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Sample records for radiosterilized freeze-dried human

  1. Clinical uses of radiosterilized freeze-dried human bone: its application in buccomaxillary surgery

    International Nuclear Information System (INIS)

    Wolfsohn, B.; Taramasso, F.; Godoy, J.; Wodowoz, O.; Saldias, M.; Silva, W.; Machin, D.; Sanchez, G.; Alvarez, I.

    2008-01-01

    Full text: The objective of this paper is to evaluate the uses of different human bone tissue allografts in bucomaxillary surgery between 2005 and 2007. Presentation of our experience using single freeze dried bone allografts and associated to bovine collagen membranes (commercial registered). Twenty patients were treated with cortical struts, cancellous chips, morsellized and morsellized demineralized bone. All the grafts were processed at the INDT multi tissue bank from cardiac arrest and brain death cadaveric donors. All the tissues were radiosterilized by Gamma radiation. Bone allografts were used: 1) to optimize bone support increasing maxillar or mandible bone before implant surgery. 2) in dehiscences and fissures during the implant surgery. 3) to stimulate bone regeneration in alveolar cavity, post-apicectomies, and cystectomies as well as for bone defects. The patients were periodically evaluated using standardized protocols. All the cases were successful showing clinic and radiologically osseointegration after 6 and 12 months. Results were evaluated considering surgical technique and patients bucomaxillary rehabilitation. Clinical uses of bone allografts confirm in our experience, as scientific literature outcomes shows, are useful in patients that refuses autografts ablation. (Author)

  2. Radiosterilization of freeze-dried human amniotic Membrane and its use in the treatment of burn wound. Algerian experience

    International Nuclear Information System (INIS)

    Djefal, A.; Mahlous, M.; Nacer Khodja, A.; Larbi, M.; Larbi Daho Bachir, M.

    2001-01-01

    The present study evaluates the usefulness of human amniotic membrane as biological dressing and its efficacy in the treatment of burns comparatively to the conventional dressing. We reported the practical methods of preparation, preservation and radiation sterilisation of amnion, and the clinical results of its successful use in the treatment of 80 cases of superficial and intermediate depth dermal burns. The increased rate of healing, pain relief, good adhesion to the bed wound and absence of infection were observed

  3. The human milk oligosaccharides are not affected by pasteurization and freeze-drying.

    Science.gov (United States)

    Hahn, Won-Ho; Kim, Jaehan; Song, Seunghyun; Park, Suyeon; Kang, Nam Mi

    2017-11-06

    Human milk oligosaccharides (HMOs) are known as important factors in neurologic and immunologic development of neonates. Moreover, freeze-drying seems to be a promising storage method to improve the processes of human milk banks. However, the effects of pasteurization and freeze-drying on HMOs were not evaluated yet. The purpose of this study is to analyze and compare the HMOs profiles of human milk collected before and after the pasteurization and freeze-drying. Totally nine fresh human milk samples were collected from three healthy mothers at the first, second, and third week after delivery. The samples were treated with Holder pasteurization and freeze-drying. HMOs profiles were analyzed by matrix-assisted laser desorption/ionization (MALDI) time-of-flight/time-of-flight (TOF/TOF) mass spectrometry and compared between samples collected before and after the treatments. Human milk samples showed significantly different HMO patterns between mothers. However, HMOs were not affected by lactation periods within 3 weeks after delivery (r 2  = 0.972-0.999, p pasteurization and freeze-drying were found not to affect HMO patterns in a correlation analysis (r 2  = 0.989-0.999, p pasteurization and freeze-drying of donor milks. We hope that introducing freeze-drying to the human milk banks would be encouraged by the present study. However, the storage length without composition changes of HMOs after freeze-drying needs to be evaluated in the further studies.

  4. Acetabular reconstruction with human and bovine freeze-dried bone grafts and a reinforcement device

    Directory of Open Access Journals (Sweden)

    Ricardo Rosito

    2008-01-01

    Full Text Available BACKGROUND: This is a cohort trial (1997-2005 of 49 patients submitted to an acetabular component revision of a total hip arthroplasty, using impacted human and bovine freeze-dried cancellous bone grafts (H&FDBG and a reinforcement device. OBJECTIVE: To compare clinical/radiographic graft incorporation capability between cancellous bone grafts. PATIENTS/METHODS: There were two groups: I (n=26 receiving human grafts and II (n=25 receiving bovine grafts. The average follow-up times were 55 and 49 months, respectively. Clinical analysis was based on the Merle d'Aubigné and Postel score, and the radiographic analysis involved an established score based on Conn's et al. criteria for radiographic bone incorporation. RESULTS: No clinical/radiographic differences were found between the groups and both showed an overall rate of 88.5% and 76% of graft incorporation (p=0.424. CONCLUSION: The results presented here are comparable to those in the literature with the use of deep-FG. Therefore, cancellous bone grafts can be safely and adequately used in acetabular component revision in total hip arthroplasty.

  5. Freeze-drying of HI-6-loaded recombinant human serum albumin nanoparticles for improved storage stability.

    Science.gov (United States)

    Dadparvar, Miriam; Wagner, Sylvia; Wien, Sascha; Worek, Franz; von Briesen, Hagen; Kreuter, Jörg

    2014-10-01

    Severe intoxications with organophosphates require the immediate administration of atropine in combination with acetyl cholinesterase (AChE) reactivators such as HI-6. Although this therapy regimen enables the treatment of peripheral symptoms, the blood-brain barrier (BBB) restricts the access of the hydrophilic antidotes to the central nervous system which could lead to a fatal respiratory arrest. Therefore, HI-6-loaded albumin nanoparticles were previously developed to enhance the transport across this barrier and were able to reactivate organophosphate-(OP)-inhibited AChE in an in vitro BBB model. Since HI-6 is known to be moisture-sensitive, the feasibility of freeze-drying of the HI-6-loaded nanoparticles was investigated in the present study using different cryo- and lyoprotectants at different concentrations. Trehalose and sucrose (3%, w/v)-containing formulations were superior to mannitol concerning the physicochemical parameters of the nanoparticles whereas trehalose-containing samples were subject of a prolonged storage stability study at temperatures between -20°C and +40°C for predetermined time intervals. Shelf-life computations of the freeze-dried HI-6 nanoparticle formulations revealed a shelf-life time of 18 months when stored at -20°C. The formulations' efficacy was proven in vitro by reactivation of OP-inhibited AChE after transport over a porcine brain capillary endothelial cell layer model. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Radio-sterilization and processing of frozen human skin

    International Nuclear Information System (INIS)

    Zarate S, Herman; Aguirre H, Paulina; Silva R, Samy; Hitschfeld G, Mario

    2006-01-01

    The Laboratory of Radio-sterilized Biological Tissues Processing (LPTR) belonging to the Chilean Commission of Nuclear Energy and the International Atomic Energy Agency have played a paramount role in our country, concerning the biological tissue processing, which can be radio-sterilized as human skin, pig skin, amniotic membrane, human bone and bovine bone. The frozen radio.-sterilized human skin processing began in 2001, by means of putting into practice the knowledge acquired in training courses through the IAEA and the experience transferred by experts who visited our laboratory. The human skin processing of dead donor can be divided into 6 stages: a) Profuse washing with physiological sterilized serum in to remove the microorganisms, chemical and pharmacological compounds; b) immersion in glycerol solution at 10% to better keep the stored tissues; c) packing, to avoid post manipulation of the sterilized tissue; d) microbiological controls which allow and guarantee a sterility assurance level of 10 6 ; e) radio-sterilization, technique that consists of exposing the grafts to electromagnetic gamma waves which eliminate the microorganisms of the tissue, f) and finally, dispatching and liberation of the frozen sterilized human skin for its clinical use in different centers that take care of burned people. The LPTR receives feedback from surgeons who have used these tissues in order to improve the processing stages based in an integral quality system ISO 9001.2000. The State Health System in our country counts on limited and scarce resources to implement synthetic substitutes that is why It is considered necessary to spread the use of these noble tissues which have sterility assurance and they are processed at low price

  7. Freeze drying method

    International Nuclear Information System (INIS)

    Coppa, N.V.; Stewart, P.; Renzi, E.

    1999-01-01

    The present invention provides methods and apparatus for freeze drying in which a solution, which can be a radioactive salt dissolved within an acid, is frozen into a solid on vertical plates provided within a freeze drying chamber. The solid is sublimated into vapor and condensed in a cold condenser positioned above the freeze drying chamber and connected thereto by a conduit. The vertical positioning of the cold condenser relative to the freeze dryer helps to help prevent substances such as radioactive materials separated from the solution from contaminating the cold condenser. Additionally, the system can be charged with an inert gas to produce a down rush of gas into the freeze drying chamber to also help prevent such substances from contaminating the cold condenser

  8. Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)–chitosan scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Zhou, Aimei; Deng, Aipeng [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Yang [Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Gao, Lihu; Zhong, Zhaocai [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Shulin, E-mail: yshulin@njust.edu.cn [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2015-04-01

    Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide–chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (T{sub f}) and cooling rates was applied to obtain scaffolds with pore size ranging from 100 μm to 120 μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of T{sub f} at a slow cooling rate of 0.7 °C/min; a more rapid cooling rate under 5 °C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC–chitosan scaffolds with appropriate pores for potential tissue engineering. - Highlights: • Fabrication of recombinant human collagen-chitosan scaffolds by freezing drying • Influence of freeze drying protocols on lyophilized scaffolds • Pore size, microstructure, porosity, swelling and cell viability were compared. • The optimized porous scaffold is suitable for cell (HUVEC) seeding.

  9. Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)–chitosan scaffolds

    International Nuclear Information System (INIS)

    Zhang, Jing; Zhou, Aimei; Deng, Aipeng; Yang, Yang; Gao, Lihu; Zhong, Zhaocai; Yang, Shulin

    2015-01-01

    Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide–chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (T f ) and cooling rates was applied to obtain scaffolds with pore size ranging from 100 μm to 120 μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of T f at a slow cooling rate of 0.7 °C/min; a more rapid cooling rate under 5 °C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC–chitosan scaffolds with appropriate pores for potential tissue engineering. - Highlights: • Fabrication of recombinant human collagen-chitosan scaffolds by freezing drying • Influence of freeze drying protocols on lyophilized scaffolds • Pore size, microstructure, porosity, swelling and cell viability were compared. • The optimized porous scaffold is suitable for cell (HUVEC) seeding

  10. Freeze-dried microarterial allografts

    International Nuclear Information System (INIS)

    Raman, J.; Hargrave, J.C.

    1990-01-01

    Rehydrated freeze-dried microarterial allografts were implanted to bridge arterial defects using New Zealand White rabbits as the experimental model. Segments of artery from the rabbit ear and thigh were harvested and preserved for a minimum of 2 weeks after freeze-drying. These allografts, approximately 1 mm in diameter and ranging from 1.5 to 2.5 cm in length, were rehydrated and then implanted in low-pressure and high-pressure arterial systems. Poor patency was noted in low-pressure systems in both allografts and autografts, tested in 12 rabbits. In the high-pressure arterial systems, allografts that were freeze-dried and reconstituted failed in a group of 10 rabbits with an 8-week patency rate of 30 percent. Gamma irradiation in an effort to reduce infection and antigenicity of grafts after freeze-drying was associated with a patency rate of 10 percent at 8 weeks in this system in another group of 10 rabbits. Postoperative cyclosporin A therapy was associated with a patency rate of 22.2 percent in the high-pressure arterial system in a 9-rabbit group. Control autografts in this system in a group of 10 rabbits showed a 100 percent patency at 8 weeks. Microarterial grafts depend on perfusion pressure of the vascular bed for long-term patency. Rehydrated freeze-dried microarterial allografts do not seem to function well in lengths of 1 to 2.5 cm when implanted in a high-pressure arterial system. Freeze-dried arterial allografts are probably not antigenic

  11. Iodine and freeze-drying enhanced high-resolution MicroCT imaging for reconstructing 3D intraneural topography of human peripheral nerve fascicles.

    Science.gov (United States)

    Yan, Liwei; Guo, Yongze; Qi, Jian; Zhu, Qingtang; Gu, Liqiang; Zheng, Canbin; Lin, Tao; Lu, Yutong; Zeng, Zitao; Yu, Sha; Zhu, Shuang; Zhou, Xiang; Zhang, Xi; Du, Yunfei; Yao, Zhi; Lu, Yao; Liu, Xiaolin

    2017-08-01

    The precise annotation and accurate identification of the topography of fascicles to the end organs are prerequisites for studying human peripheral nerves. In this study, we present a feasible imaging method that acquires 3D high-resolution (HR) topography of peripheral nerve fascicles using an iodine and freeze-drying (IFD) micro-computed tomography (microCT) method to greatly increase the contrast of fascicle images. The enhanced microCT imaging method can facilitate the reconstruction of high-contrast HR fascicle images, fascicle segmentation and extraction, feature analysis, and the tracing of fascicle topography to end organs, which define fascicle functions. The complex intraneural aggregation and distribution of fascicles is typically assessed using histological techniques or MR imaging to acquire coarse axial three-dimensional (3D) maps. However, the disadvantages of histological techniques (static, axial manual registration, and data instability) and MR imaging (low-resolution) limit these applications in reconstructing the topography of nerve fascicles. Thus, enhanced microCT is a new technique for acquiring 3D intraneural topography of the human peripheral nerve fascicles both to improve our understanding of neurobiological principles and to guide accurate repair in the clinic. Additionally, 3D microstructure data can be used as a biofabrication model, which in turn can be used to fabricate scaffolds to repair long nerve gaps. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Development of freeze-dried kit for direct 99mTc -labeling of nimotuzumab to diagnose human EGFR positive tumors

    International Nuclear Information System (INIS)

    Toledo, Darien; Figueiras, Jenneby; Rojas, Gertrudis; León, Kalet; Gongora Bravo, Magdiel; Miguel Martínez, Antonio; Michel Alonso, Luis; Hernández, Ignacio; León, Mariela; Leyva, René; Hernández, Gerardo Ramses

    2016-01-01

    Epidermal growth factor receptor (EGFR), a 170 kDa transmembrane tyrosine kinase receptor which specifically binds epidermal growth factor (EGF) and transforming growth factor-a (TGFa) that are crucial in signaling cell proliferation, differentiation, and survival1. Overexpression of EGFR has been observed in breast cancer2, colorectal cancer, ovarian cancer, squamous cell lung carcinoma3 head and neck cancer4 and bladder cancer. Molecular imaging using radiopharmaceuticals directed towards EGFR could characterize the receptor status of tumors and thereby predict response to anti-EGFR agents for the treatment of cancer. Nimotuzumab is a humanized anti-EGFR monoclonal antibody5 designed to reduce immunogenicity and rate of clearance from the body6. Radiolabelled formulations of nimotuzumab would have applications for non-invasive imaging in order to characterize EGFR-positive tumors and thus to select patient populations that could benefit from therapy7, 8. The studies described in this work were designed to develop and evaluate the in vitro and in vivo the properties of a radiolabeled freeze dried kit of nimotuzumab and to determine its potential for radio immunodiagnostic applications. (author)

  13. Preparation of redispersible liposomal dry powder using an ultrasonic spray freeze-drying technique for transdermal delivery of human epithelial growth factor.

    Science.gov (United States)

    Yin, Fei; Guo, Shiyan; Gan, Yong; Zhang, Xinxin

    2014-01-01

    In this work, an ultrasonic spray freeze-drying (USFD) technique was used to prepare a stable liposomal dry powder for transdermal delivery of recombinant human epithelial growth factor (rhEGF). Morphology, particle size, entrapment efficiency, in vitro release, and skin permeability were systematically compared between rhEGF liposomal dry powder prepared using USFD and that prepared using a conventional lyophilization process. Porous and spherical particles with high specific area were produced under USFD conditions. USFD effectively avoided formation of ice crystals, disruption of the bilayer structure, and drug leakage during the liposome drying process, and maintained the stability of the rhEGF liposomal formulation during storage. The reconstituted rhEGF liposomes prepared from USFD powder did not show significant changes in morphology, particle size, entrapment efficiency, or in vitro release characteristics compared with those of rhEGF liposomes before drying. Moreover, the rhEGF liposomal powder prepared with USFD exhibited excellent enhanced penetration in ex vivo mouse skin compared with that for powder prepared via conventional lyophilization. The results suggest that ultrasonic USFD is a promising technique for the production of stable protein-loaded liposomal dry powder for application to the skin.

  14. A freeze dried kit formulation for the preparation of 99m Tc labelled human polyclonal IgG for the detection of infection and inflammation

    International Nuclear Information System (INIS)

    Pedraza L, M.

    1996-01-01

    A freeze dried kit formulation for the preparation of 99m Tc-labelled human polyclonal IgG for the detection of infection and inflammation employing direct methods for protein labeling was developed. The method comprises reduction of intrinsic disulphide bridges within the antibody molecule by the use of the reductant 2-mercaptoethanol. Following a subsequent purification, the resulting reduced antibody is labeled via Sn 2+ reduction of pertechnetate in the presence of a weak competing ligand ethane-1-hydroxy-1,1-diphosphonate (EHDP). High labeling efficiencies (>90%) were obtained with high in vitro stability and without effect upon antibody immunoreactivity. Methods of analysis were also established permitting identification of radiochemical impurities which may be present in radiopharmaceutical solution. 99m Tc-polyclonal IgG prepared by the kit method was evaluated for scintigraphic localization of inflammatory lesions and abscesses in rabbits. Data demonstrated that the 99m Tc-polyclonal IgG after kit-reconstitution shows excellent stability and is an effective imaging agent of infection and/or inflammation. (Author)

  15. Impregnation of leather during "freeze-drying"

    DEFF Research Database (Denmark)

    Storch, Mikkel; Vestergaard Poulsen Sommer, Dorte; Hovmand, Ida

    2016-01-01

    Freeze-drying is a recognized method for the preservation of waterlogged objects. Naturally, freeze-drying has also been used for waterlogged archaeological leather often after treatment with Na2.EDTA and impregnation with PEG; but the treated leather sometimes suffers from “excessive drying......” becoming too stiff and brittle. The aim of this study was to examine the effect of a conventional freeze-drying method against an alternative freeze-drying method that preserves the natural moisture content of the leather. Both new and archaeological waterlogged leather were included in the study...... suggest that the process which takes place within the leather during the freeze-drying in not actual freeze-drying, but rather a sophisticated way of distributing the impregnating agent. The pure ice phase freezes out, but the impregnating agent remains liquid as the temperature does not become low enough...

  16. Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)-chitosan scaffolds.

    Science.gov (United States)

    Zhang, Jing; Zhou, Aimei; Deng, Aipeng; Yang, Yang; Gao, Lihu; Zhong, Zhaocai; Yang, Shulin

    2015-04-01

    Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide-chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (Tf) and cooling rates was applied to obtain scaffolds with pore size ranging from 100μm to 120μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of Tf at a slow cooling rate of 0.7°C/min; a more rapid cooling rate under 5°C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC-chitosan scaffolds with appropriate pores for potential tissue engineering. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Platelet rich fibrin combined with decalcified freeze-dried bone allograft for the treatment of human intrabony periodontal defects: a randomized split mouth clinical trail.

    Science.gov (United States)

    Agarwal, Ashish; Gupta, Narinder Dev; Jain, Avikal

    2016-01-01

    Polypeptide growth factors of platelet rich fibrin (PRF) have the potential to regenerate periodontal tissues. Osteoinductive property of demineralized freeze-dried bone allograft (DFDBA) has been successfully utilized in periodontal regeneration. The aim of the present randomized, split mouth, clinical trial was to determine the additive effects of PRF with a DFDBA in the treatment of human intrabony periodontal defects. Sixty interproximal infrabony defects in 30 healthy, non-smoker patients diagnosed with chronic periodontitis were randomly assigned to PRF/DFDBA group or the DFDBA/saline. Clinical [pocket depth (PD), clinical attachment level (CAL) and gingival recession (REC)] and radiographic (bone fill, defect resolution and alveolar crest resorption) measurements were made at baseline and at a 12-month evaluation. Compared with baseline, 12-month results indicated that both treatment modalities resulted in significant changes in all clinical and radiographic parameters. However, the PRP/DFDBA group exhibited statistically significantly greater changes compared with the DFDBA/saline group in PD (4.15 ± 0.84 vs 3.60 ± 0.51 mm), CAL (3.73 ± 0.74 vs 2.61 ± 0.68 mm), REC (0.47 ± 0.56 vs 1.00 ± 0.61 mm), bone fill (3.50 ± 0.67 vs 2.49 ± 0.64 mm) and defect resolution (3.73 ± 0.63 vs 2.75 ± 0.57 mm). Observations indicate that a combination of PRF and DFDBA is more effective than DFDBA with saline for the treatment of infrabony periodontal defects.

  18. Mechanisms of deterioration of nutrients. [of freeze dried foods

    Science.gov (United States)

    Karel, M.; Flink, J. M.

    1976-01-01

    Methods which produce freeze dried foods of improved quality were examined with emphasis on storage stability. Specific topics discussed include: microstructure of freeze dried systems, investigation of structural changes in freeze dried systems, artificial food matrices, osmotic preconcentration to yield improved quality freeze dried fruits, and storage stability of osmotically preconcentrated freeze dried fruits.

  19. Histologic and histomorphometric evaluation of bone regeneration using nanocrystalline hydroxyapatite and human freeze-dried bone graft : An experimental study in rabbit.

    Science.gov (United States)

    Sadeghi, Rokhsareh; Najafi, Mohammad; Semyari, Hassan; Mashhadiabbas, Fatemeh

    2017-03-01

    Bone regeneration is an important concern in periodontal treatment and implant dentistry. Different biomaterials and surgical techniques have been used for this purpose. The aim of the present study was to compare the effect of nanocrystalline hydroxyapatite and human freeze-dried bone graft (FDBG) in regeneration of rabbit calvarium bony defects by histologic and histomorphometric evaluation. In this experimental study, three similar defects, measuring 8 mm in diameter, were created in the calvaria of 16 white New Zealand rabbits. Two defects were filled with FDBG and nanocrystalline hydroxyapatite silica gel, while the other one remained unfilled to be considered as control. All the defects were covered with collagen membranes. During the healing period, two animals perished; so 14 rabbits were divided into two groups: half of them were euthanized after 6 weeks of healing and the other half after 12 weeks. The specimens were subjected to histologic and histomorphometric examinations for assessment of the following variables: percentage of bone formation and residual graft material, inflammation scores, patterns of bone formation and type of newly formed bone. The percentages of new bone formation after 6 weeks were 14.22 ± 7.85, 21.57 ± 6.91, and 20.54 ± 10.07% in FDBG, NanoBone, and control defects. These values were 27.54 ± 20.19, 23.86 ± 6.27, and 26.48 ± 14.18% in 12-week specimens, respectively. No significant differences were found in the amount of bone formation between the groups. With regard to inflammation, the control and NanoBone groups showed significantly less inflammation compared to FDBG at the 6-week healing phase (P = 0.04); this difference was not significant in the 12-week specimens. Based on the results of this experimental study, both NanoBone and FDBG exhibited a similar effect on bone formation.

  20. Well-plate freeze-drying

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Rantanen, Jukka; Grohganz, Holger

    2015-01-01

    Abstract Context: Freeze-drying in presence of excipients is a common practice to stabilize biomacromolecular formulations. The composition of this formulation is known to affect the quality of the final product. Objective: The aim of this study was to evaluate freeze-drying in well-plates as a h......Abstract Context: Freeze-drying in presence of excipients is a common practice to stabilize biomacromolecular formulations. The composition of this formulation is known to affect the quality of the final product. Objective: The aim of this study was to evaluate freeze-drying in well......-plates as a high throughput platform for formulation screening of freeze-dried products. Methods: Model formulations consisting of mannitol, sucrose and bovine serum albumin were freeze-dried in brass well plates, plastic well plates and vials. Physical properties investigated were solid form, residual moisture......, cake collapse and reconstitution time. Results: Samples freeze-dried in well-plates had an acceptable visual cake appearance. Solid form analysis by high throughput X-ray powder diffraction indicated comparable polymorphic outcome independent of the container. The expected increase in moisture level...

  1. Rehydration kinetics of freeze-dried carrots

    NARCIS (Netherlands)

    Vergeldt, F.J.; Dalen, van G.; Duijster, A.J.; Voda, A.; Khalloufi, S.; Vliet, van L.J.; As, van H.; Duynhoven, van J.P.M.; Sman, van der R.G.M.

    2014-01-01

    Rehydration kinetics by two modes of imbibition is studied in pieces of freeze-dried winter carrot, after different thermal pre-treatments. Water ingress at room temperature is measured in real time by in situ MRI and NMR relaxometry. Blanched samples rehydrate substantially faster compared to

  2. Sysnthesis of powders by freeze-drying

    International Nuclear Information System (INIS)

    Johnson, S.M.; Gusman, M.I.; Hildenbrand, D.L.

    1988-01-01

    The freeze-drying method of synthesizing powders of the superconducting oxide YBa 2 Cu 3 O 7 - δ is described. This process produces homogeneous, submicron powders of high purity. The effects of salt selection, solution concentration and pH on the process are described. Some evaluation of the sintering behavior and the effects on critical current density are included

  3. SOME STUDIES ON FREEZE - DRIED ARTERIES

    Directory of Open Access Journals (Sweden)

    H. Sadeghi - Nejad

    1970-01-01

    Full Text Available (1 The secondary stage of freeze - drying, particularly the last day, is not important and I suggest the whole procedure is reduced to three days, the primary stage occupying two of these. (2 The mothod used obtains the satisfactory low level of residual moisture. RESUME (3 Experiments on reconstitution with saline and distilled water show that distilled water is more satisfactory and I suggest that saline should not he used.

  4. Atmospheric freeze drying assisted by power ultrasound

    International Nuclear Information System (INIS)

    Santacatalina, J V; Cárcel, J A; Garcia-Perez, J V; Mulet, A; Simal, S

    2012-01-01

    Atmospheric freeze drying (AFD) is considered an alternative to vacuum freeze drying to keep the quality of fresh product. AFD allows continuous drying reducing fix and operating costs, but presents, as main disadvantage, a long drying time required. The application of power ultrasound (US) can accelerate AFD process. The main objective of the present study was to evaluate the application of power ultrasound to improve atmospheric freeze drying of carrot. For that purpose, AFD experiments were carried out with carrot cubes (10 mm side) at constant air velocity (2 ms −1 ), temperature (−10°C) and relative humidity (10%) with (20.5 kWm −3 ,USAFD) and without (AFD) ultrasonic application. A diffusion model was used in order to quantify the influence of US in drying kinetics. To evaluate the quality of dry products, rehydration capacity and textural properties were determined. The US application during AFD of carrot involved the increase of drying rate. The effective moisture diffusivity identified in USAFD was 73% higher than in AFD experiments. On the other hand, the rehydration capacity was higher in USAFD than in AFD and the hardness of dried samples did not show significant (p<0.05) differences. Therefore, US application during AFD significantly (p<0.05) sped-up the drying process preserving the quality properties of the dry product.

  5. Amnion s and radio-sterilized porcine skin use as potential matrices for the development of human skin substitutes

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Reyes F, M. L.; Reboyo B, D.; Velasquillo M, M. C.; Sanchez S, R.; Brena M, A. M.; Ibarra P, J. C.

    2014-10-01

    The injuries by burns constitute a primordial problem of public health; they cause a high mortality index, severe physical and psychological disability, etc. The autologous skin transplant is the replacement therapy recommended for its treatment, but in patients that present a high percentage of burnt skin; this is not possible to carry out. Another strategy is the transplant of donated skin; however, due to the little donation that exists in our country is not very feasible to apply this treatment. A challenge of the tissues engineering is to develop biological skin substitutes, based on cells and amnion s, favoring the cutaneous regeneration and quick repair of injuries, diminishing this way the hospitalization expenses. At present skin substitutes that can equal to the same skin do not exist. On the other hand, the mesenchymal stromal cells (Msc) represent an alternative to achieve this objective; since has been demonstrated that the Msc participate in the tissue repair by means of inhibition of pro-inflammatory cytokines and differentiation to dermal fibroblasts and keratinocytes. To apply the Msc in cutaneous injuries a support material is required that to allow transplanting these cells to a lesion or burn. The radio-sterilized human amnion and the radio-sterilized porcine skin, processed by the Radio-Sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares (ININ), are biomaterials that are used as temporary cutaneous coverings. We suppose that these two matrices will be appropriate for the growth and maintenance in cultivation of the Msc, to generate two biological skin substitutes, in collaboration with the Biotechnology Laboratory of the Instituto Nacional de Rehabilitacion. (Author)

  6. Initial boost release of transforming growth factor-β3 and chondrogenesis by freeze-dried bioactive polymer scaffolds.

    Science.gov (United States)

    Krüger, Jan Philipp; Machens, Isabel; Lahner, Matthias; Endres, Michaela; Kaps, Christian

    2014-12-01

    In cartilage regeneration, bio-activated implants are used in stem and progenitor cell-based microfracture cartilage repair procedures. Our aim was to analyze the chondrogenic potential of freeze-dried resorbable polymer-based polyglycolic acid (PGA) scaffolds bio-activated with transforming growth factor-β3 (TGFB3) on human subchondral mesenchymal progenitor cells known from microfracture. Progenitor cells derived from femur heads were cultured in the presence of freeze-dried TGFB3 in high-density pellet culture and in freeze-dried TGFB3-PGA scaffolds for chondrogenic differentiation. Progenitor cell cultures in PGA scaffolds as well as pellet cultures with and without continuous application of TGFB3 served as controls. Release studies showed that freeze-dried TGFB3-PGA scaffolds facilitate a rapid, initial boost-like release of 71.5% of TGFB3 in the first 10 h. Gene expression analysis and histology showed induction of typical chondrogenic markers like type II collagen and formation of cartilaginous tissue in TGFB3-PGA scaffolds seeded with subchondral progenitor cells and in pellet cultures stimulated with freeze-dried TGFB3. Chondrogenic differentiation in freeze-dried TGFB3-PGA scaffolds was comparable to cultures receiving TGFB3 continuously, while non-stimulated controls did not show chondrogenesis during prolonged culture for 14 days. These results suggest that bio-activated, freeze-dried TGFB3-PGA scaffolds have chondrogenic potential and are a promising tool for stem cell-mediated cartilage regeneration.

  7. Limonene encapsulation in freeze dried gellan systems.

    Science.gov (United States)

    Evageliou, Vasiliki; Saliari, Dimitra

    2017-05-15

    The encapsulation of limonene in freeze-dried gellan systems was investigated. Surface and encapsulated limonene content was determined by measurement of the absorbance at 252nm. Gellan matrices were both gels and solutions. For a standard gellan concentration (0.5wt%) gelation was induced by potassium or calcium chloride. Furthermore, gellan solutions of varying concentrations (0.25-1wt%) were also studied. Limonene was added at two different concentrations (1 and 2mL/100g sample). Gellan gels encapsulated greater amounts of limonene than solutions. Among all gellan gels, the KCl gels had the greater encapsulated limonene content. However, when the concentration of limonene was doubled in these KCl gels, the encapsulated limonene decreased. The surface limonene content was significant, especially for gellan solutions. The experimental conditions and not the mechanical properties of the matrices were the dominant factor in the interpretation of the observed results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Freeze-drying of mononuclear cells derived from umbilical cord blood followed by colony formation.

    Directory of Open Access Journals (Sweden)

    Dity Natan

    Full Text Available BACKGROUND: We recently showed that freeze-dried cells stored for 3 years at room temperature can direct embryonic development following cloning. However, viability, as evaluated by membrane integrity of the cells after freeze-drying, was very low; and it was mainly the DNA integrity that was preserved. In the present study, we improved the cells' viability and functionality after freeze-drying. METHODOLOGY/PRINCIPAL FINDINGS: We optimized the conditions of directional freezing, i.e. interface velocity and cell concentration, and we added the antioxidant EGCG to the freezing solution. The study was performed on mononuclear cells (MNCs derived from human umbilical cord blood. After freeze-drying, we tested the viability, number of CD34(+-presenting cells and ability of the rehydrated hematopoietic stem cells to differentiate into different blood cells in culture. The viability of the MNCs after freeze-drying and rehydration with pure water was 88%-91%. The total number of CD34(+-presenting cells and the number of colonies did not change significantly when evaluated before freezing, after freeze-thawing, and after freeze-drying (5.4 x 10(4+/-4.7, 3.49 x 10(4+/-6 and 6.31 x 10(4+/-12.27 cells, respectively, and 31+/-25.15, 47+/-45.8 and 23.44+/-13.3 colonies, respectively. CONCLUSIONS: This is the first report of nucleated cells which have been dried and then rehydrated with double-distilled water remaining viable, and of hematopoietic stem cells retaining their ability to differentiate into different blood cells.

  9. Freeze-Dried Human Red Blood Cells

    Science.gov (United States)

    1992-04-15

    period in the liquid state. 2. The levels of glycolytic intermediates (ATP, adenosine 5’triphosphate; 2,3-DPG 2, 3- diphosphoglycerate ) in rehydrated...8217 diphosphate, ADP; adenosine 5 monophosphate, AMP; 2,3- diphosphoglycerate . 2.3-DPG and lactate: (2) measurement of cell indices (mean cell volume (MCV), mean...monophosphate: 2,3-DPG. 2.3- diphosphoglycerate : MCV. Mean Cell Volume: MCH, Mean Cell Hemoglobin: MCHC, Mean Cell Hemoglobin Concentrations. ** Lactate levels

  10. Physical Stability of Freeze-Dried Isomalt Diastereomer Mixtures

    DEFF Research Database (Denmark)

    Koskinen, Anna-Kaisa; Fraser-Miller, Sara J.; Bøtker, Johan P.

    2016-01-01

    Purpose Isomalt is a sugar alcohol used as an excipient in commercially available solid oral dosage forms. The potential of isomalt as a novel freeze-drying excipient was studied in order to increase knowledge of the behavior of isomalt when it is freeze-dried. Methods Isomalt was freeze-dried in......Purpose Isomalt is a sugar alcohol used as an excipient in commercially available solid oral dosage forms. The potential of isomalt as a novel freeze-drying excipient was studied in order to increase knowledge of the behavior of isomalt when it is freeze-dried. Methods Isomalt was freeze......-dried in four different diastereomer compositions and its physical stability was investigated with differential scanning calorimetry, Fourier-transform infrared and Raman spectroscopy, X-ray powder diffraction, Karl-Fischer titration and thermogravimetric analysis in order to verify the solid state form...... of the diastereomer compositions showed signs of physical instability when stored in the highest relative humidity condition. The four different crystalline diastereomer mixtures showed specific identifiable solid state properties. Conclusions Isomalt was shown to be a suitable excipient for freeze-drying. Preferably...

  11. SOME STUDIES ABOUT CEREALS BEHAVIOR DURING FREEZE DRYING PROCESS

    Directory of Open Access Journals (Sweden)

    GABRIELA-VICTORIA MNERIE

    2009-05-01

    Full Text Available The paper presents some special method and equipment and the principal advantages of freeze-dried food. The freeze drying is a good method of freeze-drying for make some experiments with many kind of cereals, for the improvement that in food production. It is necessary and is possible to study the corn oil extract, wheat flour, the maltodextrin from corn, modified cornstarch, spice extracts, soy sauce, hydrolyzed wheat gluten, partially hydrogenated soybean and cottonseed oil etc. That is very porous, since it occupies the same volume as the original and so rehydrates rapidly. There is less loss of flavour and texture than with most other methods of drying.

  12. CFD modelling of condensers for freeze-drying processes

    Indian Academy of Sciences (India)

    Freeze-drying; condenser; CFD simulation; mathematical modelling; ... it is used for the stabilization and storage of delicate, heat-sensitive materials .... The effect of the surface mass transfer has been included in the continuity equation and.

  13. Accelerated storage testing of freeze-dried Pseudomonas ...

    African Journals Online (AJOL)

    Accelerated storage testing of freeze-dried Pseudomonas fluorescens BTP1, ... of all P. fluorescens strains were not significantly different and thermal inactivation ... useful to the development of improved reference materials and samples held ...

  14. Simulation Study on Freeze-drying Characteristics of Mashed Beef

    OpenAIRE

    Tambunan, Armansyah H; Solahudin, M; Rahajeng, Estri

    2000-01-01

    Drying characteristic of a particular product is important in analyzing the appropriateness of the drying method for the product. This is especially important for freeze drying, which is known as the most expensive drying method, asideji-om its good drying quality. The objectives of this experiment are to develop a computer simulation program using a retreating drying-frontmodel for predicting freeze drying characteristics of mashed nteat, especially for the influence of sublimation temperatu...

  15. Mechanisms of deterioration of nutrients. [improved quality of freeze-dried foods

    Science.gov (United States)

    Karel, M.; Flink, J. M.

    1978-01-01

    Methods for improving the quality of freeze-dried foods were investigated. Areas discussed include: (1) microstructure of freeze-dried systems, (2) structural changes in freeze-dried systems, (3) artificial food matrices, and (4) osmotic preconcentration to yield improved freeze-dried products.

  16. Study on irradiaiton of freezing-dried Wuchang fish

    International Nuclear Information System (INIS)

    Chen Xueling; Cheng Wei; Xiong Guangquan; Ye Lixiu; Chen Yuxia; Guan Jian; He Jianjun

    2008-01-01

    The effects of irradiation on sterilization and storage time for the freezing-dried Wuchang fish were studied. The results show that the number of the coliform group in freezing-dried Wuchang fish irradiated at 1kGy can be acceptable according to the national industrial standard and the number of bacteria decrease from 3100cfu/g to <10cfu/g after irradiation. With the optimal irradiation dose 1kGy the shelf life of Wuchang fish can be extended over one year. (authors)

  17. Preservation of pathological tissue specimens by freeze-drying for immunohistochemical staining and various molecular biological analyses.

    Science.gov (United States)

    Matsuo, S; Sugiyama, T; Okuyama, T; Yoshikawa, K; Honda, K; Takahashi, R; Maeda, S

    1999-05-01

    Conditions of preserving DNA, RNA and protein in pathological specimens are of great importance as degradation of such macromolecules would critically affect results of molecular biological analysis. The feasibility of freeze-drying as a means of preserving pathological tissue samples for molecular analysis has previously been shown. In the present study, further tests on long-term storage conditions and analyses of freeze-dried samples by polymerase chain reaction (PCR), reverse transcriptase (RT)-PCR, western blotting and immunohistochemistry are reported. Rat chromosomal DNA of freeze-dried samples stored for 4 years showed slight degradation while RNA degradation was more prominently seen at an earlier stage of storage. However, these 4 year DNA and RNA samples were still able to serve as a template for some PCR and RT-PCR analyses, respectively. Overexpression of c-erbB-2 and p53 protein was demonstrated by western blotting and immunohistochemical staining using freeze-dried human breast cancer tissues. Although macromolecules in freeze-dried samples degrade to some extent during the preservation period, they should still be of value for certain molecular biological analyses and morphological examination; hence, providing more convenient and inexpensive ways of pathological tissue storage.

  18. Microbiological problems in radiosterilization

    International Nuclear Information System (INIS)

    Czerniawski, E.

    1997-01-01

    Microbiological problems connected with radiosterilization of medical materials, pharmaceuticals and cosmetics have been discussed in detail. Dose-response relationship for different bacteria has been shown. Recommended sterilization and postirradiation control procedures have been described. 24 refs, 6 figs, 5 tabs

  19. Apparatus for freeze drying of biologic and sediment samples

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Freeze drying to obtain water from individual samples, though not complicated, usually requires considerable effort to maintain the cold traps on a 24-hr basis. In addition, the transfer of a sample from sample containers to freeze-dry flasks is usually made with some risk of contamination to the sample. If samples are large, 300 g to 600 g, usually several days are required to dry the samples. The use of an unattended system greatly improves personnel and drying efficiency. Commercial freeze dryers are not readily applicable to the problems of collecting water from individual samples, and lab-designed collectors required sample transfer and continual replenishment of the dry ice. A freeze-dry apparatus for collecting water from individual sediment and/or biological samples was constructed to determine the tritium concentrations in fish for dose calcaluations and the tritium distribution in sediment cores for water movement studies. The freeze, dry apparatus, which can handle eight samples simultaneously and conveniently, is set up for unattended 24-hr operation and is designed to avoid sample transfer problems

  20. Accelerated storage testing of freeze-dried Pseudomonas ...

    African Journals Online (AJOL)

    Erika-Chris

    Full Length Research Paper ... was possible to compare rate constants of survival for the freeze-dried P. fluorescens ... studying and predicting the survival loss rate of the ... Erlenmeyer flask containing 3000 ml King B medium. ... The strain was grown in 20 L bioreactor (Biolafite) containing 15 L .... fermented banana media.

  1. Freeze Drying of Fruits and Vegetables: A Laboratory Experiment.

    Science.gov (United States)

    Noble, Richard D.

    1979-01-01

    Describes a laboratory experiment for freeze-drying fruits and vegetables which aims to expose college students to the principles of drying and simultaneous heat and mass transfer. The experimental apparatus, procedure of the experiment, and data analysis are also included. (HM)

  2. Freeze drying method for preparing radiation source material

    International Nuclear Information System (INIS)

    Mosley, W.C.; Smith, P.K.

    1976-01-01

    Fabrication of a neutron source is specifically claimed. A palladium/californium solution is freeze dried to form a powder which, through conventional powder metallurgy, is shaped into a source containing the californium evenly distributed through a palladium metal matrix. (E.C.B.)

  3. Preparation of superconducting powders by freeze-drying

    International Nuclear Information System (INIS)

    Johnson, S.M.; Gusman, M.I.; Rowcliffe, D.J.; Geballe, T.H.; Sun, J.Z.

    1987-01-01

    A method of preparing superconducting powders by freeze-drying is described. Powders produced by this method are homogeneous, have high purities, and are very reactive. Materials sintered from these powders have densities up to 89% of the theoretical density, and exhibit very sharp resistivity drops and large Meissner effects. The microstructure of the materials is very sensitive to the sintering temperature

  4. Freeze-drying of filamentous fungi and yeasts

    NARCIS (Netherlands)

    Tan, C.S.

    2011-01-01

    The aim of this thesis was to optimize the freeze-drying protocol for fungi in general and for those genera that do not survive this preservation method, in particular. To this end, the influence of the cooling rate, the lyoprotectant and the drying process itself was examined. Since most fungi

  5. Sintering of a freeze-dried 10 mol% Y2O3-stabilized zirconia

    International Nuclear Information System (INIS)

    Rakotoson, A.; Paulus, M.

    1983-01-01

    After presenting the results of freeze drying a sulfate solution, the authors describe a preparation process in which the freeze-drying technique by addition of a suspension of stabilized zirconia in the liquid solution before freeze-drying. This process breaks the polymeric chains, increases the green density of the compact, and decreases the sintering temperature. The mechanisms involved are discussed

  6. Validation of radiosterilization dose of human skin dressings for burnt treatment: preliminary study

    International Nuclear Information System (INIS)

    Castro, E.

    2008-01-01

    Full text: Due to the need for better materials to treat burnt patients, the Peruvian Institute of Nuclear Energy (IPEN) and the Rosa Guerzoni Chambergo Tissue Bank are collaborating for developing human skin dressings. Skin was procured from living donors, who surgically were performed a dermolipectomy. Exclusion criteria, stated by the Peruvian Organization for Transplant and Donation were observed. Glycerolized human skin dressings were processed at the tissue bank and sent to IPEN, where the gamma irradiation sterilizing dose was determined. The purpose of this work is to validate the radiation sterilization dose delivered to human skin dressings using the IAEA Code of Practice for the Radiation Sterilization of Tissue Allografts: Requirements for Validation and Routine Control. A batch of human skin dressings was tested. Average values of bioburden present in ten samples was 30 UFC/item, obtaining a sub-sterilization dose of 4 kGy. Irradiations were performed in the GammacellExcel 220. Sterility tests performed fulfilled the requirements established by the Code, achieving a validated dose value of 19.7 kGy. This preliminary study, that should be repeated in two other batches of processed human skin, allows to diminish 25 kGy the sterilizing dose to the stated above dose value, in a frame of a quality assurance system that also comprises the processes held at tissue banks previous irradiation. It also permit the availability of these materials in Peruvian hospitals. (Author)

  7. Heat and Mass Transfer Model in Freeze-Dried Medium

    Science.gov (United States)

    Alfat, Sayahdin; Purqon, Acep

    2017-07-01

    There are big problems in agriculture sector every year. One of the major problems is abundance of agricultural product during the peak of harvest season that is not matched by an increase in demand of agricultural product by consumers, this causes a wasted agricultural products. Alternative way was food preservation by freeze dried method. This method was already using heat transfer through conduction and convection to reduce water quality in the food. The main objective of this research was to design a model heat and mass transfer in freeze-dried medium. We had two steps in this research, the first step was design of medium as the heat injection site and the second was simulate heat and mass transfer of the product. During simulation process, we use physical property of some agriculture product. The result will show how temperature and moisture distribution every second. The method of research use finite element method (FEM) and will be illustrated in three dimensional.

  8. Encapsulation of black carrot juice using spray and freeze drying.

    Science.gov (United States)

    Murali, S; Kar, Abhijit; Mohapatra, Debabandya; Kalia, Pritam

    2015-12-01

    Black carrot juice extracted using pectinase enzyme was encapsulated in three different carrier materials (maltodextrin 20DE, gum arabic and tapioca starch) using spray drying at four inlet temperatures (150, 175, 200 and 225 ℃) and freeze drying at a constant temperature of - 53 ℃ and vacuum of 0.22-0.11 mbar with the constant feed mixture. The products were analyzed for total anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and total colour change. For both the drying methods followed in this study, maltodextrin 20DE as the carrier material has proven to be better in retaining maximum anthocyanin and antioxidant activity compared to gum arabic and tapioca starch. The best spray dried product, was obtained at 150 ℃. The most acceptable was the freeze dried product with maximum anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and colour change. © The Author(s) 2014.

  9. The impact of freeze-drying infant fecal samples on measures of their bacterial community profiles and milk-derived oligosaccharide content

    Directory of Open Access Journals (Sweden)

    Zachery T. Lewis

    2016-01-01

    Full Text Available Infant fecal samples are commonly studied to investigate the impacts of breastfeeding on the development of the microbiota and subsequent health effects. Comparisons of infants living in different geographic regions and environmental contexts are needed to aid our understanding of evolutionarily-selected milk adaptations. However, the preservation of fecal samples from individuals in remote locales until they can be processed can be a challenge. Freeze-drying (lyophilization offers a cost-effective way to preserve some biological samples for transport and analysis at a later date. Currently, it is unknown what, if any, biases are introduced into various analyses by the freeze-drying process. Here, we investigated how freeze-drying affected analysis of two relevant and intertwined aspects of infant fecal samples, marker gene amplicon sequencing of the bacterial community and the fecal oligosaccharide profile (undigested human milk oligosaccharides. No differences were discovered between the fecal oligosaccharide profiles of wet and freeze-dried samples. The marker gene sequencing data showed an increase in proportional representation of Bacteriodes and a decrease in detection of bifidobacteria and members of class Bacilli after freeze-drying. This sample treatment bias may possibly be related to the cell morphology of these different taxa (Gram status. However, these effects did not overwhelm the natural variation among individuals, as the community data still strongly grouped by subject and not by freeze-drying status. We also found that compensating for sample concentration during freeze-drying, while not necessary, was also not detrimental. Freeze-drying may therefore be an acceptable method of sample preservation and mass reduction for some studies of microbial ecology and milk glycan analysis.

  10. Freeze-drying wet digital prints: An option for salvage?

    International Nuclear Information System (INIS)

    Juergens, M C; Schempp, N

    2010-01-01

    On the occasion of the collapse of the Historical Archive of the City of Cologne in March 2009 and the ensuing salvage effort, questions were raised about the use of freeze-drying for soaked digital prints, a technique that has not yet been evaluated for these materials. This study examines the effects of immersion, air-drying, drying in a blotter stack, freezing and freeze-drying on 35 samples of major digital printing processes. The samples were examined visually before, during and after testing; evaluation of the results was qualitative. Results show that some prints were already damaged by immersion alone (e.g. bleeding inks and soluble coatings) to the extent that the subsequent choice of drying method made no significant difference any more. For those samples that did survive immersion, air-drying proved to be crucial for water-sensitive prints, since any contact with the wet surface caused serious damage. Less water-sensitive prints showed no damage throughout the entire procedure, regardless of drying method. Some prints on coated media suffered from minor surface disruption up to total delamination of the surface coating due to the formation of ice crystals during shock-freezing. With few exceptions, freeze-drying did not cause additional damage to any of the prints that hadn't already been damaged by freezing. It became clear that an understanding of the process and materials is important for choosing an appropriate drying method.

  11. Freeze-dried processing of tungsten heavy alloys

    International Nuclear Information System (INIS)

    White, G.D.; Gurwell, W.E.

    1989-06-01

    Tungsten heavy alloy powders were produced from freeze-dried aqueous solutions of ammonium metatungstate and, principally, sulfates of Ni and Fe. The freeze-dried salts were calcined and hydrogen reduced to form very fine, homogeneous, low-density, W heavy alloy powders having a coral-like structure with elements of approximately 0.1 μm in diameter. The powders yield high green strength and sinterability. Tungsten heavy alloy powders of 70%, 90%, and 96% W were prepared by freeze drying, compacted, and solid-state (SS) sintered to fully density at temperatures as low as 1200 degree C and also at conventional liquid-phase (LP) sintering temperatures. Solid-state sintered microstructures contained polygonal W grains with high contiguity; the matrix did not coat and separate the W grains to form low-contiguity, high-ductility structures. Liquid-phase sintered microstructures were very conventional in appearance, having W spheroids of low contiguity. All these materials were found to be brittle. High levels of residual S accompanied by segregation of the S to all the microstructural interfaces are principally responsible for the brittleness; problems with S could be eliminated by using Fe and Ni nitrates rather than the sulfates. 9 refs., 22 figs., 3 tabs

  12. Effects of gamma radiation on freeze-dried wheat seeds

    International Nuclear Information System (INIS)

    Ajayi, N.O.; Larsson, B.

    1975-07-01

    The effect of radiation on freeze-dried wheat seeds are reported. The response of the various parts of the seedling to radiation was found to differ from one another. There was no significant modification of the effect of radiation on the shoot and root growth, while the growth of the coleoptile was slightly reduced in the frezze-dried seeds. The change in the shoot growth-absorbed dose relationship reported by others to occur at high doses for oven-dried as compared to air-dried barley seeds was not seen for the control and freeze-dried wheat seeds. The freeze-dried seeds are believed to show only the effect of radiation without any modification due to drying as such. The dose-effect relationships may be splited into functions characterised by different radiosensitivity. The high sensitivty effect is mainly taking place within the first 40 krad of energy absorption, and the low sensitivity is dominating at higher doses. (author)

  13. Shrinkage of spray-freeze-dried microparticles of pure protein for ballistic injection by manipulation of freeze-drying cycle.

    Science.gov (United States)

    Straller, Georg; Lee, Geoffrey

    2017-10-30

    Spray-freeze-drying was used to produce shrivelled, partially-collapsed microparticles of pure proteins that may be suitable for use in a ballistic injector. Various modifications of the freeze drying cycle were examined for their effects on collapse of the pure protein microparticles. The use of annealing at a shelf temperature of up to +10°C resulted in no visible particle shrinkage. This was because of the high T g ' of the pure protein. Inclusion of trehalose or sucrose led to particle shrinkage because of the plasticizing effects of the disaccharides on the protein. Only by extending the duration of primary drying from 240 to 2745min at shelf temperatures in the range -12 to -8°C were shrivelled, wrinkled particles of bSA and bCA of reduced porosity obtained. Manipulation of the freeze-drying cycle used for SFD can therefore be used to modify particle morphology and increase particle density. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Combined electrohydrodynamic (EHD) and vacuum freeze drying of shrimp

    International Nuclear Information System (INIS)

    Hu, Yucai; Huang, Qiang; Bai, Yaxiang

    2013-01-01

    To improve the drying qualities of shrimp, a combination of electrohydrodynamic (EHD) and vacuum freeze drying (FD) is examined. The drying rate, the shrinkage, the rehydration ratio, and the sensory properties including the color and trimness of the dried products under different drying methods (including combination drying of EHD and FD, EHD drying and FD drying) are measured. Compared with FD and EHD drying alone, the combined process consumes less drying time, and the product processed by combined drying displays lower shrinkage, higher rehydration rate and better sensory qualities.

  15. Evaluation of Genotoxicity and 28-day Oral Dose Toxicity on Freeze-dried Powder of Tenebrio molitor Larvae (Yellow Mealworm)

    OpenAIRE

    Han, So-Ri; Yun, Eun-Young; Kim, Ji-Young; Hwang, Jae Sam; Jeong, Eun Ju; Moon, Kyoung-Sik

    2014-01-01

    The larval form of Tenebrio molitor (T. molitor) has been eaten in many countries and provides benefits as a new food source of protein for humans. However, no information exists regarding its safety for humans. The objective of the present study was to evaluate the genotoxicity and repeated dose oral toxicity of the freeze-dried powder of T. molitor larvae. The genotoxic potential was evaluated by a standard battery testing: bacterial reverse mutation test, in vitro chromosome aberration tes...

  16. Radiosterilization and gas sterilization

    International Nuclear Information System (INIS)

    Schultz, H.A.; Gruenewald, T.

    1987-01-01

    The book presents a survey of the principles of cold sterilization by radiation or gas, and also of the problems involved. The reader who has to do with sterilization of some kind or other, as e.g. sterilization of medicaments, medical supplies, medical device, drugs, grafts, or food, will find comprehensive information on the various available methods and their effects, as well as on monitoring procedures and techniques, together with proposals for efficient documentation and validation of partial sterilization processes. The introduction summarizes the potentials of sterilization by radiation, and the subsequent by radiation, and the subsequent chapters explain the specific applicabilities of radiosterilization along with the most important criteria for evaluating the sterilizing efficiency. The information on the legal situation and requirements takes into account the second amendment of the Medical Preparations Act. With 38 figs., 14 tabs [de

  17. Folic acid content in thermostabilized and freeze-dried space shuttle foods

    Science.gov (United States)

    Lane, H. W.; Nillen, J. L.; Kloeris, V. L.

    1995-01-01

    This study was designed to determine whether freeze-dried and thermostabilized foods on a space shuttle contain adequate folate and to investigate any effects of freeze-drying on folacin. Frozen vegetables were analyzed after three states of processing: thawed; cooked; and rehydrated. Thermostabilized items were analyzed as supplied with no further processing. Measurable folate decreased in some freeze-dried vegetables and increased in others. Folacin content of thermostabilized food items was comparable with published values. We concluded that although the folacin content of some freeze-dried foods was low, adequate folate is available from the shuttle menu to meet RDA guidelines.

  18. Successful long-term preservation of rat sperm by freeze-drying.

    Directory of Open Access Journals (Sweden)

    Takehito Kaneko

    Full Text Available BACKGROUND: Freeze-drying sperm has been developed as a new preservation method where liquid nitrogen is no longer necessary. An advantage of freeze-drying sperm is that it can be stored at 4 °C and transported at room temperature. Although the successful freeze-drying of sperm has been reported in a number of animals, the possibility of long-term preservation using this method has not yet been studied. METHODOLOGY/PRINCIPAL FINDINGS: Offspring were obtained from oocytes fertilized with rat epididymal sperm freeze-dried using a solution containing 10 mM Tris and 1 mM EDTA adjusted to pH 8.0. Tolerance of testicular sperm to freeze-drying was increased by pre-treatment with diamide. Offspring with normal fertility were obtained from oocytes fertilized with freeze-dried epididymal sperm stored at 4 °C for 5 years. CONCLUSIONS AND SIGNIFICANCE: Sperm with -SS- cross-linking in the thiol-disulfide of their protamine were highly tolerant to freeze-drying, and the fertility of freeze-dried sperm was maintained for 5 years without deterioration. This is the first report to demonstrate the successful freeze-drying of sperm using a new and simple method for long-term preservation.

  19. Analysis for Difficulty during Freeze-Drying Feizixiao Lychees

    Directory of Open Access Journals (Sweden)

    L. L. Huang

    2017-01-01

    Full Text Available Compared to other cultivar lychees, volume density of Feizixiao lychee was higher due to serious shrinkage during freeze-drying (FD. Guiwei lychee and Nuomici lychee were used for comparison in order to illuminate the reason of the aforementioned phenomenon. Lower prefreezing temperature could not improve the volume density of Feizixiao lychee. Microstructure results show that pulp cell of Feizixiao lychee (tail was smaller and more compact than Guiwei and Nuomici lychee pulp cell. In addition, there is a membrane around the surface of Feizixiao lychee pulp. And the microstructure of Feizixiao lychee tip pulp cell is different from tail pulp cell. Membrane and tip pulp cell are both smaller and more compact than tail pulp cell. These structure differences hinder the moisture removing of Feizixiao lychee during FD. Removing the membrane and tip pulp could not improve the volume density of Feizixiao lychee. Ultrasound treatment for 30 min could significantly enhance the volume density of Feizixiao lychee.

  20. Freeze-drying behaviour of pasteurized whole egg

    International Nuclear Information System (INIS)

    Melike Sakin; Merve Samli; Gizem Kor, A.; Figen Kaymak-Ertekin

    2009-01-01

    Because it provides full nutritional and certain desirable functional attributes, egg products are widely used as ingredients in many food products. Dried egg is especially valuable for being stable, easily mixable and having a long shelf life. It is necessary to know the effects of drying conditions onto the moisture removal behaviour and the functional properties of the powder product, to serve the egg powder as an alternative. An experimental study was conducted to achieve an understanding of the freeze-drying behaviour of pasteurized whole egg having 24% dry solids. In order to determine the moisture removal behaviour; the percent moisture loss (w/w), the average moisture content and the drying rates were obtained, the drying curves were developed and total drying times were determined, also the movement of the dry-wet boundary between the frozen layer and the dry porous layer formed by sublimation of ice crystals were investigated during a complete process. The physical properties of pasteurized whole egg such as; colour, water activity (a w ), the morphological structure (through SEM analysis) and functional properties (foam stability and dissolubility) were determined. The net colour change (ΔE) was about 22, independent of layer thickness. The water activity decreased to 0.22 at the end of drying. The SEM images of freeze-dried and slightly milled egg powder samples at magnification levels of 500 and 1000 showed the porous structure caused by sublimation of ice crystals generated within the egg structure during air blast freezing. The dissolubility and foaming capacity of powder egg were observed to be lower compared to those of pasteurized liquid egg. (author)

  1. The effect of dryer load on freeze drying process design.

    Science.gov (United States)

    Patel, Sajal M; Jameel, Feroz; Pikal, Michael J

    2010-10-01

    Freeze-drying using a partial load is a common occurrence during the early manufacturing stages when insufficient amounts of active pharmaceutical ingredient (API) are available. In such cases, the immediate production needs are met by performing lyophilization with less than a full freeze dryer load. However, it is not obvious at what fractional load significant deviations from full load behavior begin. The objective of this research was to systematically study the effects of variation in product load on freeze drying behavior in laboratory, pilot and clinical scale freeze-dryers. Experiments were conducted with 5% mannitol (high heat and mass flux) and 5% sucrose (low heat and mass flux) at different product loads (100%, 50%, 10%, and 2%). Product temperature was measured in edge as well as center vials with thermocouples. Specific surface area (SSA) was measured by BET gas adsorption analysis and residual moisture was measured by Karl Fischer. In the lab scale freeze-dryer, the molar flux of inert gas was determined by direct flow measurement using a flowmeter and the molar flux of water vapor was determined by manometric temperature measurement (MTM) and tunable diode laser absorption spectroscopy (TDLAS) techniques. Comparative pressure measurement (capacitance manometer vs. Pirani) was used to determine primary drying time. For both 5% mannitol and 5% sucrose, primary drying time decreases and product temperature increases as the load on the shelves decreases. No systematic variation was observed in residual moisture and vapor composition as load decreased. Further, SSA data suggests that there are no significant freezing differences under different load conditions. Independent of dryer scale, among all the effects, variation in radiation heat transfer from the chamber walls to the product seems to be the dominant effect resulting in shorter primary drying time as the load on the shelf decreases (i.e., the fraction of edge vials increases).

  2. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    International Nuclear Information System (INIS)

    Liu, Yang; Ren, Li; Wang, Yingjun

    2014-01-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair

  3. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China)

    2014-05-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

  4. A freeze dried kit formulation for the preparation of {sup 99m} Tc labelled human polyclonal IgG for the detection of infection and inflammation; Desarrollo del nucleo equipo {sup 99m} Tc-IgG humana para la deteccion `In vivo` de procesos inflamatorios

    Energy Technology Data Exchange (ETDEWEB)

    Pedraza L, M

    1996-11-01

    A freeze dried kit formulation for the preparation of {sup 99m}Tc-labelled human polyclonal IgG for the detection of infection and inflammation employing direct methods for protein labeling was developed. The method comprises reduction of intrinsic disulphide bridges within the antibody molecule by the use of the reductant 2-mercaptoethanol. Following a subsequent purification, the resulting reduced antibody is labeled via Sn{sup 2+} reduction of pertechnetate in the presence of a weak competing ligand ethane-1-hydroxy-1,1-diphosphonate (EHDP). High labeling efficiencies (>90%) were obtained with high in vitro stability and without effect upon antibody immunoreactivity. Methods of analysis were also established permitting identification of radiochemical impurities which may be present in radiopharmaceutical solution. {sup 99m} Tc-polyclonal IgG prepared by the kit method was evaluated for scintigraphic localization of inflammatory lesions and abscesses in rabbits. Data demonstrated that the {sup 99m} Tc-polyclonal IgG after kit-reconstitution shows excellent stability and is an effective imaging agent of infection and/or inflammation. (Author).

  5. Optimization Of Freeze-Dried Starter For Yogurt By Full Factorial Experimental Design

    Directory of Open Access Journals (Sweden)

    Chen He

    2015-12-01

    Full Text Available With the rapidly development of fermented milk product, it is significant for enhancing the performance of starter culture. This paper not only investigated the influence of anti-freeze factors and freeze-drying protective agents on viable count, freeze-drying survival rate and yield of Lactobacillus bulgaricus (LB and Streptococcus thermophilus (ST, but also optimized the bacteria proportion of freeze-dried starter culture for yogurt by full factorial experimental design. The results showed as following: the freeze-drying protective agents or anti-freeze factors could enhanced survival rate of LB and ST; the freeze-dried LB and ST powders containing both of anti-freeze factors and freeze-drying protective agents had higher viable count and freeze-drying survival rate that were 84.7% and 79.7% respectively; In terms of fermentation performance, the best group of freeze-dried starter for yogurt was the compound of LB3 and ST2.

  6. Model-based optimization of the primary drying step during freeze-drying

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; Van Bockstal, Pieter-Jan; Nopens, Ingmar

    2015-01-01

    Since large molecules are considered the key driver for growth of the pharmaceutical industry, the focus of the pharmaceutical industry is shifting from small molecules to biopharmaceuticals: around 50% of the approved biopharmaceuticals are freeze-dried products. Therefore, freeze- drying is an ...

  7. Application of freeze-drying technology in manufacturing orally disintegrating films.

    Science.gov (United States)

    Liew, Kai Bin; Odeniyi, Michael Ayodele; Peh, Kok-Khiang

    2016-01-01

    Freeze drying technology has not been maximized and reported in manufacturing orally disintegrating films. The aim of this study was to explore the freeze drying technology in the formulation of sildenafil orally disintegrating films and compare the physical properties with heat-dried orally disintegrating film. Central composite design was used to investigate the effects of three factors, namely concentration of carbopol, wheat starch and polyethylene glycol 400 on the tensile strength and disintegration time of the film. Heat-dried films had higher tensile strength than films prepared using freeze-dried method. For folding endurance, freeze-dried films showed improved endurance than heat-dried films. Moreover, films prepared using freeze-dried methods were thicker and had faster disintegration time. Formulations with higher amount of carbopol and starch showed higher tensile strength and thickness whereas formulations with higher PEG 400 content showed better flexibility. Scanning electron microscopy showed that the freeze-dried films had more porous structure compared to the heat-dried film as a result of the release of water molecule from the frozen structure when it was subjected to freeze drying process. The sildenafil film was palatable. The dissolution profiles of freeze-dried and heat-dried films were similar to Viagra® with f2 of 51.04 and 65.98, respectively.

  8. Freeze-drying-induced changes in the properties of graphene oxides

    International Nuclear Information System (INIS)

    Ham, Heon; Van Khai, Tran; Gil Na, Han; Jung Kwon, Yong; Yeon Cho, Hong; Woo Kim, Hyoun; Park, No-Hyung; So, Dae Sup; Lee, Joon-Woo

    2014-01-01

    We have characterized and evaluated changes in graphene oxide (GO) induced by means of freeze-drying. In order to evaluate these changes, we investigated the effects of freeze-drying and chemical reduction processes on the structure, morphology, chemical composition, and Raman properties of GO and reduced GO. The freeze-dried GO had a pore structure, maintaining a pored morphology even after thermal annealing. The freeze-dried samples were composed of a single folded nanosheet or a few nanosheets stacked and folded. The oxygen-containing functional groups were removed not only during the freeze-drying but also during the reduction processes, with an accompanying decrease in the average size of the sp 2 carbon domain (i.e. an increase in the I D /I G value). (papers)

  9. Development of freeze-dried miyeokguk, Korean seaweed soup, as space food sterilized by irradiation

    International Nuclear Information System (INIS)

    Song, Beom-Seok; Park, Jin-Gyu; Kim, Jae-Hun; Choi, Jong-Il; Ahn, Dong-Hyun; Hao, Chen; Lee, Ju-Woon

    2012-01-01

    The purpose of this study was to evaluate microbial populations, Hunter's color values (L ⁎ , a ⁎ , b ⁎ ) and the sensory quality of freeze-dried miyeokguk, Korean seaweed soup, in order to use it as space food. Microorganisms were not detected in non-irradiated freeze-dried miyeokguk within the detection limit of 1.00 log CFU/g. However, the microbial population in rehydrated miyeokguk was 7.01 log CFU/g after incubation at 35 °C for 48 h, indicating that freeze-dried miyeokguk was not sterilized by heat treatment during the preparation process. Bacteria in the freeze-dried miyeokguk were tentatively identified as Bacillus cereus, B. subtilis, Enterobacter hormaechei, and Ancinetobacter genomosp. using the 16S rDNA sequencing. In samples that were gamma-irradiated above 10 kGy, it was confirmed that all microorganisms were inactivated. Hunter's color values of the samples irradiated at doses less than 10 kGy were not significantly altered from their baseline appearance (p>0.05). Sensory evaluation showed that preference scores in all sensory properties decreased when freeze-dried miyeokguk was irradiated at doses greater than 10 kGy. Therefore, the results of this study suggest that gamma irradiation at 10 kGy is sufficient to sterilize freeze-dried miyeokguk without significant deterioration in the sensory quality, and thus, the freeze-dried and irradiated miyeokguk at 10 kGy fulfills the microbiological requirements as space food. - Highlights: ► 10 kGy gamma-irradiation is sufficient for sterilization of freeze-dried miyeokguk. ► Sensory quality of freeze-dried miyeokguk decreased after >10 kGy gamma irradiation. ► 10 kGy gamma-irradiation sterilizes freeze-dried miyeokguk and makes it optimal for use as space food.

  10. Effects of annealing on the physical properties of therapeutic proteins during freeze drying process.

    Science.gov (United States)

    Lim, Jun Yeul; Lim, Dae Gon; Kim, Ki Hyun; Park, Sang-Koo; Jeong, Seong Hoon

    2018-02-01

    Effects of annealing steps during the freeze drying process on etanercept, model protein, were evaluated using various analytical methods. The annealing was introduced in three different ways depending on time and temperature. Residual water contents of dried cakes varied from 2.91% to 6.39% and decreased when the annealing step was adopted, suggesting that they are directly affected by the freeze drying methods Moreover, the samples were more homogenous when annealing was adopted. Transition temperatures of the excipients (sucrose, mannitol, and glycine) were dependent on the freeze drying steps. Size exclusion chromatography showed that monomer contents were high when annealing was adopted and also they decreased less after thermal storage at 60°C. Dynamic light scattering results exhibited that annealing can be helpful in inhibiting aggregation and that thermal storage of freeze-dried samples preferably induced fragmentation over aggregation. Shift of circular dichroism spectrum and of the contents of etanercept secondary structure was observed with different freeze drying steps and thermal storage conditions. All analytical results suggest that the physicochemical properties of etanercept formulation can differ in response to different freeze drying steps and that annealing is beneficial for maintaining stability of protein and reducing the time of freeze drying process. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Development of freeze-dried miyeokguk, Korean seaweed soup, as space food sterilized by irradiation

    Science.gov (United States)

    Song, Beom-Seok; Park, Jin-Gyu; Kim, Jae-Hun; Choi, Jong-Il; Ahn, Dong-Hyun; Hao, Chen; Lee, Ju-Woon

    2012-08-01

    The purpose of this study was to evaluate microbial populations, Hunter's color values (L*, a*, b*) and the sensory quality of freeze-dried miyeokguk, Korean seaweed soup, in order to use it as space food. Microorganisms were not detected in non-irradiated freeze-dried miyeokguk within the detection limit of 1.00 log CFU/g. However, the microbial population in rehydrated miyeokguk was 7.01 log CFU/g after incubation at 35 °C for 48 h, indicating that freeze-dried miyeokguk was not sterilized by heat treatment during the preparation process. Bacteria in the freeze-dried miyeokguk were tentatively identified as Bacillus cereus, B. subtilis, Enterobacter hormaechei, and Ancinetobacter genomosp. using the 16S rDNA sequencing. In samples that were gamma-irradiated above 10 kGy, it was confirmed that all microorganisms were inactivated. Hunter's color values of the samples irradiated at doses less than 10 kGy were not significantly altered from their baseline appearance (p>0.05). Sensory evaluation showed that preference scores in all sensory properties decreased when freeze-dried miyeokguk was irradiated at doses greater than 10 kGy. Therefore, the results of this study suggest that gamma irradiation at 10 kGy is sufficient to sterilize freeze-dried miyeokguk without significant deterioration in the sensory quality, and thus, the freeze-dried and irradiated miyeokguk at 10 kGy fulfills the microbiological requirements as space food.

  12. Chromosomal integrity of freeze-dried mouse spermatozoa after 137Cs γ-ray irradiation

    International Nuclear Information System (INIS)

    Kusakabe, Hirokazu; Kamiguchi, Yujiroh

    2004-01-01

    This study demonstrated that freeze-dried mouse spermatozoa possess strong resistance to 137 Cs γ-ray irradiation at doses of up to 8 Gy. Freeze-dried mouse spermatozoa were rehydrated and injected into mouse oocytes with an intracytoplasmic sperm injection (ICSI) technique. Most oocytes can be activated after ICSI by using spermatozoa irradiated with γ-rays before and after freeze-drying. Sperm chromosome complements were analyzed at the first cleavage metaphase. Chromosome aberrations increased in a dose-dependent manner in the spermatozoa irradiated before freeze-drying. However, no increase in oocytes with chromosome aberrations was observed when fertilized by spermatozoa that had been irradiated after freeze-drying, as compared with freeze-dried spermatozoa that had not been irradiated. These results suggest that both the chromosomal integrity of freeze-dried spermatozoa, as well as their ability to activate oocytes, were protected from γ-ray irradiation at doses at which chromosomal damage is found to be strongly induced in spermatozoa suspended in solution

  13. Simulation of the process kinetics and analysis of physicochemical properties in the freeze drying of kale

    Science.gov (United States)

    Dziki, Dariusz; Polak, Renata; Rudy, Stanisław; Krzykowski, Andrzej; Gawlik-Dziki, Urszula; Różyło, Renata; Miś, Antoni; Combrzyński, Maciej

    2018-01-01

    Investigations were performed to study the freeze-drying process of kale (Brassica oleracea L. var acephala). The process of freeze-drying was performed at temperatures of 20, 40, and 60°C for whole pieces of leaves and for pulped leaves. The kinetics of the freeze-drying of both kale leaves and kale pulp were best described by the Page model. The increasing freeze-drying temperature from 20 to 60°C induced an approximately two-fold decrease in the drying time. Freeze-drying significantly increased the value of the lightness, delta Chroma, and browning index of kale, and had little influence on the hue angle. The highest increase in the lightness and delta Chroma was observed for whole leaves freeze-dried at 20°C. An increase in the drying temperature brought about a slight decrease in the lightness, delta Chroma and the total colour difference. Pulping decreased the lightness and hue angle, and increased browning index. Freeze-drying engendered a slight decrease in the total phenolics content and antioxidant activity, in comparison to fresh leaves. The temperature of the process and pulping had little influence on the total phenolics content and antioxidant activity of dried kale, but significantly decreased the contents of chlorophyll a and chlorophyll b.

  14. Key composition optimization of meat processed protein source by vacuum freeze-drying technology

    Directory of Open Access Journals (Sweden)

    Yan Ma

    2018-05-01

    Full Text Available Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined. Keywords: Ham, Tenderloin, Vacuum freeze-dry, Processing, Optimization

  15. Mechanisms of deterioration of nutrients. [freeze drying methods for space flight food

    Science.gov (United States)

    Karel, M.; Flink, J. M.

    1974-01-01

    Methods are reported by which freeze dried foods of improved quality will be produced. The applicability of theories of flavor retention has been demonstrated for a number of food polymers, both proteins and polysacchardies. Studies on the formation of structures during freeze drying have been continued for emulsified systems. Deterioration of organoleptic quality of freeze dried foods due to high temperature heating has been evaluated and improved procedures developed. The influence of water activity and high temperature on retention of model flavor materials and browning deterioration has been evaluated for model systems and food materials.

  16. Refurbishing of a Freeze Drying Machine, used in Nuclear Medicine for Radiopharmaceuticals Production

    International Nuclear Information System (INIS)

    Gaytan-Gallardo, E.; Desales-Galeana, G.

    2006-01-01

    The refurbishing of a freeze drying machine used in the radiopharmaceuticals production, applied in nuclear medicine in the Radioactive Materials Department of the Nuclear Research National Institute in Mexico (ININ in Spanish), is presented. The freeze drying machine was acquired in the 80's decade and some components started having problems. Then it was necessary to refurbish this equipment by changing old cam-type temperature controllers and outdated recording devices, developing a sophisticated software system that substitutes those devices. The system is composed by a freeze drying machine by Hull, AC output modules for improved temperature control, a commercial data acquisition card, and the software system

  17. Amnion s and radio-sterilized porcine skin use as potential matrices for the development of human skin substitutes; Uso de amnios y piel porcina radioesterilizados como matrices potenciales para el desarrollo de sustitutos de piel humana

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E.; Reyes F, M. L.; Reboyo B, D. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Velasquillo M, M. C.; Sanchez S, R.; Brena M, A. M.; Ibarra P, J. C., E-mail: esther.martinez@inin.gob.mx [Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco No. 289, Col. Arenal de Guadalupe, 14389 Mexico D. F. (Mexico)

    2014-10-15

    The injuries by burns constitute a primordial problem of public health; they cause a high mortality index, severe physical and psychological disability, etc. The autologous skin transplant is the replacement therapy recommended for its treatment, but in patients that present a high percentage of burnt skin; this is not possible to carry out. Another strategy is the transplant of donated skin; however, due to the little donation that exists in our country is not very feasible to apply this treatment. A challenge of the tissues engineering is to develop biological skin substitutes, based on cells and amnion s, favoring the cutaneous regeneration and quick repair of injuries, diminishing this way the hospitalization expenses. At present skin substitutes that can equal to the same skin do not exist. On the other hand, the mesenchymal stromal cells (Msc) represent an alternative to achieve this objective; since has been demonstrated that the Msc participate in the tissue repair by means of inhibition of pro-inflammatory cytokines and differentiation to dermal fibroblasts and keratinocytes. To apply the Msc in cutaneous injuries a support material is required that to allow transplanting these cells to a lesion or burn. The radio-sterilized human amnion and the radio-sterilized porcine skin, processed by the Radio-Sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares (ININ), are biomaterials that are used as temporary cutaneous coverings. We suppose that these two matrices will be appropriate for the growth and maintenance in cultivation of the Msc, to generate two biological skin substitutes, in collaboration with the Biotechnology Laboratory of the Instituto Nacional de Rehabilitacion. (Author)

  18. Sperm preservation by freeze-drying for the conservation of wild animals.

    Directory of Open Access Journals (Sweden)

    Takehito Kaneko

    Full Text Available Sperm preservation is a useful technique for the maintenance of biological resources in experimental and domestic animals, and in wild animals. A new preservation method has been developed that enables sperm to be stored for a long time in a refrigerator at 4 °C. Sperm are freeze-dried in a solution containing 10 mM Tris and 1 mM EDTA. Using this method, liquid nitrogen is not required for the storage and transportation of sperm. We demonstrate that chimpanzee, giraffe, jaguar, weasel and the long-haired rat sperm remain viable after freeze-drying. In all species, pronuclei were formed after the injection of freeze-dried sperm into the mouse oocytes. Although preliminary, these results may be useful for the future establishment of "freeze-drying zoo" to conserve wild animals.

  19. Microstructure study of a material on the basis of YSZ obtained be freeze-drying

    International Nuclear Information System (INIS)

    Rizea, A.; Abrudeanu, M.; Petot, C.; Petot Ervas, G.

    2001-01-01

    Freeze-drying is a dehydration proceeding of the products in a frozen state, which is based on the ice sublimation process. It is a method, which leads to a very good homogeneity of the products and it allows obtaining very fine powders, which directs to reducing the sintering temperature. Freeze drying always supposes three stages: - freezing, sublimation and absorption of the residual water. The preparation of ZrO 20.91 Y 2 O 30.09 samples proceeds through the following stages: - a. solution preparation; b. solution spraying (into small droplets in liquid nitrogen); c. freeze drying processing; d. calcination of the freeze dried powder; e. powder compacting; f. sintering at four different temperature. The different structure of samples with different density are characterized on basis of micrographs. The results of these analyses are presented, discussed and explained through the chemical composition of the samples

  20. Freeze-drying and related preparation techniques for biological microprobe analysis

    International Nuclear Information System (INIS)

    Wroblewski, R.; Wroblewski, J.; Anniko, M.; Edstroem, L.P.

    1985-01-01

    An X-ray microanalytical and morphological investigation has been carried out on rapidly frozen, freeze-dried or freeze-substituted tissues. A comparison was made between different embedding and polymerization procedures following freeze-substitution and freeze-drying. The investigation also included an analysis of specimens infiltrated, embedded and polymerized by ultraviolet irradiation at low temperatures with Lowicryl HM20. The morphological preservation of Lowicryl embedded tissue was adequate for the identification of different cell structures like nuclei, mitochondria, lysosomes and different types of endoplasmic reticulum. X-ray microanalytical investigation of low temperature embedded material displayed an elemental composition of cells and organelles similar to that found in freeze-dried cyosections. Compared with freeze-dried cryosections, low temperature embedded material could be sectioned for light microscopy and area of interest chosen for further thin sectioning. This is of great importance in work with tissues with complicated morphology and heterogenous cell populations

  1. Sera radiosterilization: studies and applications

    International Nuclear Information System (INIS)

    Michelin, Severino C.

    2000-01-01

    The application of ionizing radiation for sterilization of animal serum increased rapidly over the last few years, due to the fact that most radiation-resistant living organisms (fungi, bacteria, viruses, etc.) can be readily inactivated without damage to the serum. The quality of sera sterilized by ionizing radiation has been investigated. Radiosterilization was carried out in the frozen state at doses between 25 and 50 kGy. The source of gamma radiation was cobalt 60. To demonstrate that serum proteins did not suffer alterations during the process of irradiation, SDS-PAGE, electrofocusing and non equilibrium pH gradient electrophoresis of the sera were carried out before and after irradiation. The biological efficiency of the irradiated sera was demonstrated by growth curves of several cell lines in cell cultures supplemented with it. The results demonstrated that radiosterilization is a simple and effective method for sera. (author)

  2. Model for heat and mass transfer in freeze-drying of pellets.

    Science.gov (United States)

    Trelea, Ioan Cristian; Passot, Stéphanie; Marin, Michèle; Fonseca, Fernanda

    2009-07-01

    Lyophilizing frozen pellets, and especially spray freeze-drying, have been receiving growing interest. To design efficient and safe freeze-drying cycles, local temperature and moisture content in the product bed have to be known, but both are difficult to measure in the industry. Mathematical modeling of heat and mass transfer helps to determine local freeze-drying conditions and predict effects of operation policy, and equipment and recipe changes on drying time and product quality. Representative pellets situated at different positions in the product slab were considered. One-dimensional transfer in the slab and radial transfer in the pellets were assumed. Coupled heat and vapor transfer equations between the temperature-controlled shelf, the product bulk, the sublimation front inside the pellets, and the chamber were established and solved numerically. The model was validated based on bulk temperature measurement performed at two different locations in the product slab and on partial vapor pressure measurement in the freeze-drying chamber. Fair agreement between measured and calculated values was found. In contrast, a previously developed model for compact product layer was found inadequate in describing freeze-drying of pellets. The developed model represents a good starting basis for studying freeze-drying of pellets. It has to be further improved and validated for a variety of product types and freeze-drying conditions (shelf temperature, total chamber pressure, pellet size, slab thickness, etc.). It could be used to develop freeze-drying cycles based on product quality criteria such as local moisture content and glass transition temperature.

  3. Key composition optimization of meat processed protein source by vacuum freeze-drying technology.

    Science.gov (United States)

    Ma, Yan; Wu, Xingzhuang; Zhang, Qi; Giovanni, Vigna; Meng, Xianjun

    2018-05-01

    Vacuum freeze-drying technology is a high technology content, a wide range of knowledge of technology in the field of drying technology is involved, it is also a method of the most complex drying equipment, the largest energy consumption, the highest cost of drying method, but due to the particularity of its dry goods: the freeze-drying food has the advantages of complex water performance is good, cooler and luster of freezing and drying food to maintain good products, less nutrient loss, light weight, easy to carry transportation, easy to long-term preservation, and on the quality is far superior to the obvious advantages of other dried food, making it become the forefront of drying technology research and development. The freeze-drying process of Chinese style ham and western Germany fruit tree tenderloin is studied in this paper, their eutectic point, melting point and collapse temperature, freeze-drying curve and its heat and mass transfer characteristics are got, then the precool temperature and the highest limiting temperature of sublimation interface are determined. The effect of system pressure on freeze-dried rate in freeze-drying process is discussed, and the method of regulating pressure circularly is determined.

  4. Effects of six substances on the growth and freeze-drying of Lactobacillus delbrueckii subsp. bulgaricus.

    Science.gov (United States)

    Chen, He; Huang, Jie; Shi, Xiaoyu; Li, Yichao; Liu, Yu

    2017-01-01

    The efficacy of Lactobacillus delbrueckii subsp. bulgaricus as starter cultures for the dairy industry depends largely on the number of viable and active cells. Freeze-drying is the most convenient and successful method to preserve the bacterial cells. However, not all strains survived during freeze-drying. The effects of six substances including NaCl, sorbitol, mannitol, mannose, sodium glutamate, betaine added to the MRS medium on the growth and freeze-drying survival rate and viable counts of Lb. delbrueckii subsp. bulgaricus were studied through a single-factor test and Plackett-Burman design. Subsequently, the optimum freeze-drying conditions of Lb. delbrueckii subsp. bulgaricus were determined. Lb. delbrueckii subsp. bulgaricus survival rates were up to the maximum of 42.7%, 45.4%, 23.6%, while the concentrations of NaCl, sorbitol, sodium glutamate were 0.6%, 0.15%, 0.09%, respectively. In the optimum concentration, the viable counts in broth is 6.1, 6.9, 5.13 (×108 CFU/mL), respectively; the viable counts in freeze-drying power are 3.09, 5.2, 2.7 (×1010 CFU/g), respectively. Three antifreeze factors including NaCl, sorbitol, sodium glutamate have a positive effect on the growth and freeze-drying of Lb. delbrueckii subsp. bulgaricus. The results are beneficial for developing Lb. delbrueckii subsp. bulgaricus.

  5. Cell growth and resistance of Lactococcus lactis subsp. lactis TOMSC161 following freezing, drying and freeze-dried storage are differentially affected by fermentation conditions.

    Science.gov (United States)

    Velly, H; Fonseca, F; Passot, S; Delacroix-Buchet, A; Bouix, M

    2014-09-01

    To investigate the effects of fermentation parameters on the cell growth and on the resistance to each step of the freeze-drying process of Lactococcus lactis subsp. lactis TOMSC161, a natural cheese isolate, using a response surface methodology. Cells were cultivated at different temperatures (22, 30 and 38°C) and pH (5·6, 6·2 and 6·8) and were harvested at different growth phases (0, 3 and 6 h of stationary phase). Cultivability and acidification activity losses of Lc. lactis were quantified after freezing, drying, 1 and 3 months of storage at 4 and 25°C. Lactococcus lactis was not damaged by freezing but was sensitive to drying and to ambient temperature storage. Moreover, the fermentation temperature and the harvesting time influenced the drying resistance of Lc. lactis. Lactococcus lactis cells grown in a whey-based medium at 32°C, pH 6·2 and harvested at late stationary phase exhibited both an optimal growth and the highest resistance to freeze-drying and storage. A better insight on the individual and interaction effects of fermentation parameters made it possible the freeze-drying and storage preservation of a sensitive strain of technological interest. Evidence on the particularly damaging effect of the drying step and the high-temperature storage is presented. © 2014 The Society for Applied Microbiology.

  6. Assessing storage of stability and mercury reduction of freeze-dried Pseudomonas putida within different types of lyoprotectant

    Science.gov (United States)

    Azoddein, Abdul Aziz Mohd; Nuratri, Yana; Azli, Faten Ahada Mohd; Bustary, Ahmad Bazli

    2017-12-01

    Pseudomonas putida is a potential strain in biological treatment to remove mercury contained in the effluent of petrochemical industry due to its mercury reductase enzyme that able to reduce ionic mercury to elementary mercury. Freeze-dried P. putida allows easy, inexpensive shipping, handling and high stability of the product. This study was aimed to freeze dry P. putida cells with addition of lyoprotectant. Lyoprotectant was added into the cells suspension prior to freezing. Dried P. putida obtained was then mixed with synthetic mercury. Viability of recovery P. putida after freeze dry was significantly influenced by the type of lyoprotectant. Among the lyoprotectants, tween 80/ sucrose was found to be the best lyoprotectant. Sucrose was able to recover more than 78% (6.2E+09 CFU/ml) of the original cells (7.90E+09CFU/ml) after freeze dry and able to retain 5.40E+05 viable cells after 4 weeks storage at 4 °C without vacuum. Polyethylene glycol (PEG) pre-treated freeze dried cells and broth pre-treated freeze dried cells after the freeze-dry process recovered more than 64% (5.0 E+09CFU/ml) and >0.1% (5.60E+07CFU/ml). Freeze-dried P. putida cells in PEG and broth cannot survive after 4 weeks storage. Freeze dry also does not really change the pattern of growth P. putida but extension of lag time was found 1 hour after 3 weeks of storage. Additional time was required for freeze-dried P. putida cells to recover before introducing freeze-dried cells to more complicated condition such as mercury solution. The maximum mercury reduction of PEG pre-treated freeze-dried cells after freeze dry and after storage of 3 weeks was 17.91 %. The maximum of mercury reduction of tween 80/sucrose pre-treated freeze-dried cells after freeze dry and after storage 3 weeks was 25.03%. Freeze dried P. putida was found to have lower mercury reduction compare to the fresh P. putida that has been grown in agar. Result from this study may be beneficial and useful as initial reference before

  7. Microbial analysis and survey test of gamma-irradiated freeze-dried fruits for patient's food

    Science.gov (United States)

    Park, Jae-Nam; Sung, Nak-Yun; Byun, Eui-Hong; Byun, Eui-Baek; Song, Beom-Seok; Kim, Jae-Hun; Lee, Kyung-A.; Son, Eun-Joo; Lyu, Eun-Soon

    2015-06-01

    This study examined the microbiological and organoleptic qualities of gamma-irradiated freeze-dried apples, pears, strawberries, pineapples, and grapes, and evaluated the organoleptic acceptability of the sterilized freeze-dried fruits for hospitalized patients. The freeze-dried fruits were gamma-irradiated at 0, 1, 2, 3, 4, 5, 10, 12, and 15 kGy, and their quality was evaluated. Microorganisms were not detected in apples after 1 kGy, in strawberries and pears after 4 kGy, in pineapples after 5 kGy, and in grapes after 12 kGy of gamma irradiation. The overall acceptance score, of the irradiated freeze-dried fruits on a 7-point scale at the sterilization doses was 5.5, 4.2, 4.0, 4.1, and 5.1 points for apples, strawberries, pears, pineapples, and grapes, respectively. The sensory survey of the hospitalized cancer patients (N=102) resulted in scores of 3.8, 3.7, 3.9, 3.9, and 3.7 on a 5-point scale for the gamma-irradiated freeze-dried apples, strawberries, pears, pineapples, and grapes, respectively. The results suggest that freeze-dried fruits can be sterilized with a dose of 5 kGy, except for grapes, which require a dose of 12 kGy, and that the organoleptic quality of the fruits is acceptable to immuno-compromised patients. However, to clarify the microbiological quality and safety of freeze-dried fruits should be verified by plating for both aerobic and anaerobic microorganisms.

  8. Physicochemical interaction mechanism between nanoparticles and tetrasaccharides (stachyose) during freeze-drying.

    Science.gov (United States)

    Kamiya, Seitaro; Nakashima, Kenichiro

    2017-12-01

    Nanoparticle suspensions are thermodynamically unstable and subject to aggregation. Freeze-drying on addition of saccharides is a useful method for preventing aggregation. In the present study, tetrasaccharides (stachyose) was employed as an additive. In addition, we hypothesize the interactive mechanism between stachyose and the nanoparticles during freeze-drying for the first time. The mean particle size of the rehydrated freeze-dried stachyose-containing nanoparticles (104.7 nm) was similar to the initial particle size before freeze-drying (76.8 nm), indicating that the particle size had been maintained. The mean particle size of the rehydrated normal-dried stachyose-containing nanoparticles was 222.2 nm. The powder X-ray diffraction of the freeze-dried stachyose-containing nanoparticles revealed a halo pattern. The powder X-ray diffraction of the normally dried stachyose-containing nanoparticles produced mainly a halo pattern and a partial peak. These results suggest an interaction between the nanoparticles and stachyose, and that this relationship depends on whether the mixture is freeze-dried or dried normally. In the case of normal drying, although most molecules cannot move rapidly thereby settling irregularly, some stachyose molecules can arrange regularly leading to some degree of crystallization and potentially some aggregation. In contrast, during freeze-drying, the moisture sublimed, while the stachyose molecules and nanoparticles were immobilized in the ice. After sublimation, stachyose remained in the space occupied by water and played the role of a buffer material, thus preventing aggregation.

  9. Bioactivity of freeze-dried platelet-rich plasma in an adsorbed form on a biodegradable polymer material.

    Science.gov (United States)

    Nakajima, Yu; Kawase, Tomoyuki; Kobayashi, Mito; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

    2012-01-01

    Owing to the necessity for the immediate preparation from patients' blood, autologous platelet-rich plasma (PRP) limits its clinical applicability. To address this concern and respond to emergency care and other unpredictable uses, we have developed a freeze-dried PRP in an adsorbed form on a biodegradable polymer material (Polyglactin 910). On the polymer filaments of PRP mesh, which was prepared by coating the polymer mesh with human fresh PRP and subsequent freeze-drying, platelets were incorporated, and related growth factors were preserved at high levels. This new PRP mesh preparation significantly and reproducibly stimulated the proliferation of human periodontal ligament cells in vitro and neovascularization in a chorioallantoic membrane assay. A full-thickness skin defect model in a diabetic mouse demonstrated the PRP mesh, although prepared from human blood, substantially facilitated angiogenesis, granulation tissue formation, and re-epithelialization without inducing severe inflammation in vivo. These data demonstrate that our new PRP mesh preparation functions as a bioactive material to facilitate tissue repair/regeneration. Therefore, we suggest that this bioactive material, composed of allogeneic PRP, could be clinically used as a promising alternative in emergency care or at times when autologous PRP is not prepared immediately before application.

  10. Effect of Freeze-Drying on the Antioxidant Compounds and Antioxidant Activity of Selected Tropical Fruits

    Directory of Open Access Journals (Sweden)

    Muhammad Redzuan Hairuddin

    2011-07-01

    Full Text Available The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L., mango (Mangifera indica L., papaya (Carica papaya L., muskmelon (Cucumis melo L., and watermelon Citruluss lanatus (Thunb. were investigated. Significant (p < 0.05 differences, for the amounts of total phenolic compounds (TPC, were found between the fresh and freeze-dried fruit samples, except muskmelon. There was no significant (p > 0.05 change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05 higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05 but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.

  11. Rehydration of freeze-dried and convective dried boletus edulis mushrooms: effect on some quality parameters.

    Science.gov (United States)

    Hernando, I; Sanjuán, N; Pérez-Munuera, I; Mulet, A

    2008-10-01

    Quality of rehydrated products is a key aspect linked to rehydration conditions. To assess the effect of rehydration temperature on some quality parameters, experiments at 20 and 70 degrees C were performed with convective dried and freeze-dried Boletus edulis mushrooms. Rehydration characteristics (through Peleg's parameter, k(1), and equilibrium moisture, W(e)), texture (Kramer), and microstructure (Cryo-Scanning Electron Microscopy) were evaluated. Freeze-dried samples absorbed water more quickly and attained higher W(e) values than convective dried ones. Convective dehydrated samples rehydrated at 20 degrees C showed significantly lower textural values (11.9 +/- 3.3 N/g) than those rehydrated at 70 degrees C (15.7 +/- 1.2 N/g). For the freeze-dried Boletus edulis, the textural values also exhibited significant differences, being 8.2 +/- 1.3 and 10.5 +/- 2.3 N/g for 20 and 70 degrees C, respectively. Freeze-dried samples showed a porous structure that allows rehydration to take place mainly at the extracellular level. This explains the fact that, regardless of temperature, freeze-dried mushrooms absorbed water more quickly and reached higher W(e) values than convective dried ones. Whatever the dehydration technique used, rehydration at 70 degrees C produced a structural damage that hindered water absorption; consequently lower W(e) values and higher textural values were attained than when rehydrating at 20 degrees C.

  12. Nanocrystals-based Macroporous Materials Synthesized by Freeze-drying Combustion

    International Nuclear Information System (INIS)

    Yan, Ruiqiang; Chen, Yu; Lin, Ye; Chen, Fanglin

    2016-01-01

    We present a novel freeze-drying combustion method for synthesis of macroporous powders with nano-network, using Sm 0.2 Ce 0.8 O 1.9 (SDC) as an example. The metal nitrate salt solution mixed with glycine is frozen to form homogeneous nitrate/glycine mixture and then freeze-dried through sublimation of ice crystals. Upon combustion of the freeze-dried mixture, SDC powders with macroporous microstructure consisting of 10–20 nm nanocrystals, high surface area and excellent sinterability are achieved. High resolution transmission electron microscopy (HRTEM) analysis indicates that nanodomains due to aggregation/segregation of dopants in the SDC powders obtained from freeze-drying combustion are much smaller than those in the SDC powders synthesized by the conventional nitrate solution combustion approach, demonstrating better elemental homogeneity and improved conductivity. Using low cost precursors and simple processing conditions, freeze-drying combustion can be a versatile method to synthesize nanocrystalline powders with excellent composition homogeneity for broad applications.

  13. Preparation and evaluation of freeze-dried Mag3 kits for 99m Tc-labelling

    International Nuclear Information System (INIS)

    El-Mohty, A.A.; El-Ghany, E.A.; El-Kolaly, M.T.; Raieh, M.; EL-Bary, A.A.

    1996-01-01

    The freeze-dried Mag 3 kits were designed for both ligand trans chelation and direct labelling techniques. The solution of Sn-Mag 3 was sterilized by 0.22 μU mill pore filtration and dispensed in a laminar flow hood (1 m I / vial) then, the vials were introduced to the lyophilized. The process of lyophilization was continued for 24 hours. At end of the cycle, the vials were closed under nitrogen. The moisture content of the freeze-dried Mag 3 kits was determined and it was found equal to 0.1% also, the losses of tin (II) during the freeze-drying cycle did not exceed 5%. It was found that the Mag 3 freeze-dried kits were sterile, pyrogen free and does not have any unexpected toxicity. The prepared Mag 3 freeze-dried kits have high radiochemical purity > 97% and high stability for more than 8 h after labelling. The biodistribution shows rapid renal excretion at 15 min post injection. 3 figs., 4 tabs

  14. Freeze-dried spermatozoa: An alternative biobanking option for endangered species.

    Science.gov (United States)

    Anzalone, Debora Agata; Palazzese, Luca; Iuso, Domenico; Martino, Giuseppe; Loi, Pasqualino

    2018-03-01

    In addition to the iconic wild species, such as the pandas and Siberian tigers, an ever-increasing number of domestic species are also threatened with extinction. Biobanking of spermatozoa could preserve genetic heritages of extinct species, and maintain biodiversity of existing species. Because lyophilized spermatozoa retain fertilizing capacity, the aim was to assess whether freeze-dried spermatozoa are an alternative option to save endangered sheep breeds. To achieve this objective, semen was collected from an Italian endangered sheep breed (Pagliarola), and a biobank of cryopreserved and freeze-dried spermatozoa was established, and evaluated using IVF (for frozen spermatozoa) and ICSI procedures (for frozen and freeze-dried spermatozoa). As expected, the fertilizing capacity of cryopreserved Pagliarola's spermatozoa was comparable to commercial semen stocks. To evaluate the activating capability of freeze-dried spermatozoa, 108 MII sheep oocytes were subjected to ICSI, and allocated to two groups: 56 oocytes were activated by incubation with ionomycin (ICSI-FDSa) and 52 were not activated (ICSI-FDSna). Pronuclear formation (2PN) was investigated at 14-16 h after ICSI in fixed presumptive zygotes. Only artificially activated oocytes developed into blastocysts after ICSI. In the present study, freeze-dried ram spermatozoa induced blastocyst development following ICSI at a relatively high proportion, providing evidence that sperm lyophilization is an alternative, low cost storage option for biodiversity preservation of domestic species. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Evaluation of Genotoxicity and 28-day Oral Dose Toxicity on Freeze-dried Powder of Tenebrio molitor Larvae (Yellow Mealworm).

    Science.gov (United States)

    Han, So-Ri; Yun, Eun-Young; Kim, Ji-Young; Hwang, Jae Sam; Jeong, Eun Ju; Moon, Kyoung-Sik

    2014-06-01

    The larval form of Tenebrio molitor (T. molitor) has been eaten in many countries and provides benefits as a new food source of protein for humans. However, no information exists regarding its safety for humans. The objective of the present study was to evaluate the genotoxicity and repeated dose oral toxicity of the freeze-dried powder of T. molitor larvae. The genotoxic potential was evaluated by a standard battery testing: bacterial reverse mutation test, in vitro chromosome aberration test, and in vivo micronucleus test. To assess the repeated dose toxicity, the powder was administered once daily by oral gavage to Sprague-Dawley (SD) rats at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 28 days. The parameters which were applied to the study were mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination. The freezedried powder of T. molitor larvae was not mutagenic or clastogenic based on results of in vitro and in vivo genotoxicity assays. Furthermore, no treatment-related changes or findings were observed in any parameters in rats after 28 days oral administration. In conclusion, the freeze-dried powder of T. molitor larvae was considered to be non-genotoxic and the NOAEL (No Observed Adverse Effect Level) was determined to be 3000 mg/kg/day in both sexes of SD rats under our experimental conditions.

  16. Evaluation of Genotoxicity and 28-day Oral Dose Toxicity on Freeze-dried Powder of Tenebrio molitor Larvae (Yellow Mealworm)

    Science.gov (United States)

    Han, So-Ri; Yun, Eun-Young; Kim, Ji-Young; Hwang, Jae Sam; Jeong, Eun Ju

    2014-01-01

    The larval form of Tenebrio molitor (T. molitor) has been eaten in many countries and provides benefits as a new food source of protein for humans. However, no information exists regarding its safety for humans. The objective of the present study was to evaluate the genotoxicity and repeated dose oral toxicity of the freeze-dried powder of T. molitor larvae. The genotoxic potential was evaluated by a standard battery testing: bacterial reverse mutation test, in vitro chromosome aberration test, and in vivo micronucleus test. To assess the repeated dose toxicity, the powder was administered once daily by oral gavage to Sprague-Dawley (SD) rats at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 28 days. The parameters which were applied to the study were mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination. The freezedried powder of T. molitor larvae was not mutagenic or clastogenic based on results of in vitro and in vivo genotoxicity assays. Furthermore, no treatment-related changes or findings were observed in any parameters in rats after 28 days oral administration. In conclusion, the freeze-dried powder of T. molitor larvae was considered to be non-genotoxic and the NOAEL (No Observed Adverse Effect Level) was determined to be 3000 mg/kg/day in both sexes of SD rats under our experimental conditions. PMID:25071922

  17. Near-Infrared Imaging for High-Throughput Screening of Moisture-Induced Changes in Freeze-Dried Formulations

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Palou, Anna; Panouillot, Pierre Emanuel

    2014-01-01

    Evaluation of freeze-dried biopharmaceutical formulations requires careful analysis of multiple quality attributes. The aim of this study was to evaluate the use of near-infrared (NIR) imaging for fast analysis of water content and related physical properties in freeze-dried formulations. Model f...... tool for formulation development of freeze-dried samples. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci....

  18. Microencapsulation of ethanol extract propolis by maltodextrin and freeze-dried preparation

    Science.gov (United States)

    Mangiring, Getta Austin; Pratami, Diah Kartika; Hermansyah, Heri; Wijanarko, Anondho; Rohmatin, Etin; Sahlan, Muhamad

    2018-02-01

    Propolis has been known to have many benefits for human health, such as anti-cancer, anti-tumor, anti-oxidant, anti-bacterial, and anti-inflammatory. Currently in Indonesia there are quite a lot of propolis-based products, such as soap, toothpaste, skin cream, or health products in liquid form. However, there is still no propolis product in powder form. In this research, microencapsulation of propolis using maltodextrin coating with freeze drying method will be done. Propolis powder has been tested for polyphenols and it was found that crude propolis (175 ml : 75 gr) had the highest polyphenols content in powder form, 434,438 µg /mL. Soft propolis (125 ml : 125 gr) has 4.533% of moisture content, which was the lowest result in these study. And also, the soft propolis (125 ml : 125 gr) has the highest solubility in water with 69% as the result. Propolis powder that has the highest solubility can be seen morphology using Scanning Electron Mocroscope (SEM). The result of the SEM test showed that the propolised powder form did not alter the morphology of maltodextrin. This indicates the success of microencapsulation, because the form of the coating agent maltodextrin was also not uniform.

  19. Screening freeze-drying cryoprotectants for Saccharomyces boulardii by Plackett-Burman design

    Directory of Open Access Journals (Sweden)

    He CHEN

    2016-12-01

    Full Text Available As a lyophilized product, Saccharomyces boulardii has been commonly used to treat diarrhea in adults. However, there are few studies focusing on the preparation of its freeze-drying powder. This paper investigated the effect of lyoprotectants on the freeze-drying survival rate and the number of viable cells for vacuum freezedried powder of S. boulardii. Single factor experiment and Plackett-Burman design were conducted to obtain the optimal compound lyoprotectant formulations. The result showed that lactose, trehalose and sodium glutamate could significantly enhance the freeze-drying survival rate of S. boulardii. Meanwhile, all these three lyoprotectants showed positive effect on the freezedrying survival rate of the yeast, and the optimal lyoprotectant composition for S. boulardii was as follows: 18g/100mL lactose, 18g/100mL trehalose and 3g/100mL sodium glutamate.

  20. Fuzzy Logic-based expert system for evaluating cake quality of freeze-dried formulations

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Wu, Jian-Xiong; van de Weert, Marco

    2013-01-01

    Freeze-drying of peptide and protein-based pharmaceuticals is an increasingly important field of research. The diverse nature of these compounds, limited understanding of excipient functionality, and difficult-to-analyze quality attributes together with the increasing importance of the biosimilar......Freeze-drying of peptide and protein-based pharmaceuticals is an increasingly important field of research. The diverse nature of these compounds, limited understanding of excipient functionality, and difficult-to-analyze quality attributes together with the increasing importance...... critical visual features such as the degree of cake collapse, glassiness, and color uniformity. On the basis of the IA outputs, a fuzzy logic system for analysis of these freeze-dried cakes was constructed. After this development phase, the system was tested with a new screening well plate. The developed...

  1. Effect of freeze-drying on the antioxidant compounds and antioxidant activity of selected tropical fruits.

    Science.gov (United States)

    Shofian, Norshahida Mohamad; Hamid, Azizah Abdul; Osman, Azizah; Saari, Nazamid; Anwar, Farooq; Dek, Mohd Sabri Pak; Hairuddin, Muhammad Redzuan

    2011-01-01

    The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p dried fruit samples, except muskmelon. There was no significant (p > 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.

  2. Mechanical properties of freeze-dried and irradiated bone chips, fascia lata and dura mater

    International Nuclear Information System (INIS)

    De Guzman, Z.M.; Vajaradul, Y.

    1996-01-01

    The comparison strengths of freeze-dried and irradiated bone chips such as three-dimensional cortex (3DC) and two-cortico cancellous (2CC) are investigated. The results show that the (3DC) exhibits a higher compression strength (1.2kN cm -2 in deep frozen states. Rehydration of the freeze-dried bone chips after 15 min with normal saline solution restores the strength of materials by 30%. The tensile strengths of fascia lata and dura mater are also studied. A marked decrease of tensile strength is noted in the irradiated and freeze-dried samples, however, reconstitution with normal saline solution restores the tensile strength of the tissues to about 40-56%. (author). 8 refs., 6figs

  3. Method of reprocessing nuclear fuel using vacuum freeze-drying method

    International Nuclear Information System (INIS)

    Otsuka, Katsuyuki; Kondo, Isao.

    1989-01-01

    Solutions of plutonium nitrate and uranyl nitrate, spent solvents and liquid wastes separated by the treatment in the solvent extractant steps in the wet processing steps of re-processing plants or fuel fabrication plants are processed by means of freeze-drying under vacuum. Then, the solutions of plutonium nitrate and uranyl nitrate are separated into nitrates and liquid condensates and the spent solvents are freeze-dried. Thus, they are separated into tri-n-butyl phosphate, diester, monoester and n-dodecane and the liquid wastes are processed by means of freeze-drying and separated into liquids and residues. In this way, since sodium carbonate, etc. are not used, the amount of resultant liquid wastes is reduced and sodium is not contained in liquid wastes sent to an asphalt solidification step and a vitrification step, the processing steps can be simplified. (S.T.)

  4. [Freeze drying process optimization of ginger juice-adjuvant for Chinese materia medica processing and stability of freeze-dried ginger juice powder].

    Science.gov (United States)

    Yang, Chun-Yu; Guo, Feng-Qian; Zang, Chen; Cao, Hui; Zhang, Bao-Xian

    2018-02-01

    Ginger juice, a commonly used adjuvant for Chinese materia medica, is applied in processing of multiple Chinese herbal decoction pieces. Because of the raw materials and preparation process of ginger juice, it is difficult to be preserved for a long time, and the dosage of ginger juice in the processing can not be determined base on its content of main compositions. Ginger juice from different sources is hard to achieve consistent effect during the processing of traditional Chinese herbal decoction pieces. Based on the previous studies, the freeze drying of ginger juice under different shelf temperatures and vacuum degrees were studied, and the optimized freeze drying condition of ginger juice was determined. The content determination method for 6-gingerol, 8-gingerol, 10-gingerol and 6-shagaol in ginger juice and redissolved ginger juice was established. The content changes of 6-gingerol, 8-gingerol, 10-gingerol, 6-gingerol, 6-shagaol, volatile oil and total phenol were studied through the drying process and 30 days preservation period. The results showed that the freeze drying time of ginger juice was shortened after process optimization; the compositions basically remained unchanged after freeze drying, and there was no significant changes in the total phenol content and gingerol content, but the volatile oil content was significantly decreased( P <0.05). Within 30 days, the contents of gingerol, total phenol, and volatile oil were on the decline as a whole. This study has preliminarily proved the feasibility of freeze-drying process of ginger juice as an adjuvant for Chinese medicine processing. Copyright© by the Chinese Pharmaceutical Association.

  5. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Ruixin [Institute of Medical Equipment, Academy of Military and Medical Sciences, No. 106, Wandong Street, Hedong District, Tianjin 300000 (China); Jiang, Wenxue, E-mail: jiangortholivea@sina.cn [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Sun, Yufu [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Hui [Tianjin Medical University General Hospital, No. 154 Anshan Road, Tianjin, TJ 300052 (China)

    2016-09-02

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  6. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    International Nuclear Information System (INIS)

    Sun, Kai; Li, Ruixin; Jiang, Wenxue; Sun, Yufu; Li, Hui

    2016-01-01

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  7. Effect of gamma irradiation on the qualitative characteristics of freeze dried forest fruits

    International Nuclear Information System (INIS)

    Nacheva, I; Miteva, P.; Metodieva, P.; Todorova, Ya.; Loginovska, K.

    2012-01-01

    The purpose of the present investigation was to establish the effect of a combined technological processing - freeze drying and gamma sterilization - with irradiation doses of 2 and 4 kGy on the qualitative characteristics on a set of forest fruits - blackberry, blueberry, aronia, strawberry and black elder. The results prove that the freeze drying technology and the applied irradiation dose of 2 kGy is sufficient to preserve the quality and prolong the shelf life of the studied products without damage of their physical-chemical and microbiological characteristics

  8. Novel Foams Based on Freeze-Dried Renewable Vital Wheat Gluten

    DEFF Research Database (Denmark)

    Blomfeldt, Thomas O.J.; Olsson, Richard T.; Menon, Mohan

    2010-01-01

    A new way of producing rigid or semi-rigid foams from vital wheat gluten using a freeze-drying process is reported. Water/gluten-based mixtures were frozen and freeze-dried. Different foam structures were obtained by varying the mixing process and wheat gluten concentration, or by adding glycerol...... or bacterial cellulose nanofibers. MIP revealed that the foams had mainly an open porosity peaking at 93%. The average pore diameter ranged between 20 and 73 µm; the sample with the highest wheat gluten concentration and no plasticizer had the smallest pores. Immersion tests with limonene revealed...

  9. Experimental and numerical investigations on freeze-drying of porous media with prebuilt porosity

    Science.gov (United States)

    Wang, Wei; Yang, Jing; Hu, Dapeng; Pan, Yanqiu; Wang, Shihao; Chen, Guohua

    2018-05-01

    Freeze-drying of initially porous frozen material was investigated aimed at improving the process economics by reducing drying time and raising productivity. Experimental results showed that freeze-drying can be significantly enhanced by the frozen material with prebuilt porosity, and about 31% of drying time can be saved compared with the conventionally solid frozen material under the tested operating conditions. A multiphase transport model was formulated based on the local mass non-equilibrium assumption. Numerical results showed excellent agreements between measured and predicted drying curves. Analyses of saturation and temperature profiles displayed that volumetric sublimation-desorption can occur for the initially porous frozen material.

  10. Present studies on the radiosterilized drugs

    International Nuclear Information System (INIS)

    Marciniec, B.; Dettlaff, K.

    2007-01-01

    Lecture presents present status of radiosterilization of drugs and medical materials as compared to other sterilization methods. Literature review is shown on degradation of different kinds of drugs sterilized upon action of the sterilising doses of radiation

  11. Radiosterilization of medical products, pharmaceuticals and bioproducts

    International Nuclear Information System (INIS)

    1967-01-01

    A Panel on the Radiosterilization of Medical Products, Pharmaceuticals and Bioproducts was convened by the International Atomic Energy Agency on 17-19 January 1966 at its headquarters in Vienna. The purpose of the meeting was to survey the activities of the Member States in this field with a view to preparing the way for an international code of practice for the radiosterilization of medical products, in conformity with existing legal international rules. Refs, figs and tabs

  12. Radiosterilization of Tissues Preserved for Clinical Purposes: Effect on Tissue Antigenicity

    International Nuclear Information System (INIS)

    Ostrowski, K.; Kossowska, B.; Moskalewski, S.; Komender, A.; Kurnatowski, W.

    1967-01-01

    The first part of the paper contains practical considerations on the radiosterilization of preserved human bone, human and calf cartilage, cow’s fascia and aponeurosis, based on material from the Tissue Bank which produces about 2500 transplants yearly. The method of preservation and packing of each type of tissue is mentioned briefly. The preserved tissues are irradiated in a cobalt bomb or in a nuclear reactor. The conditions of irradiation and the control of sterility are described. The advantages and disadvantages of radiosterilization are discussed on the basis of the authors’ own experience and clinical reports of surgeons using radiosterilized tissues in practice. In the second part of the paper, experimental studies on the influence of freezing, lyophilization and radiosterilization on tissue antigenicity are reported. The regional lymph node reacts to an antigenic stimulus by an increased production of large, pyroninophylic cells, so-called ''blast'' cells. The rabbits used as recipients received grafts of allogeneic cancellous bone, fresh or subjected to different experimental procedures. Smears from lymph node cell suspension were prepared and the percentage of blast cells was estimated. On the basis of the lymph node response, it appears that freezing and lyophilization, as well as radiosterilization, may abolish the antigenicity of cancellous bone. The practical implication of these results for methods of preservation of tissues for clinical purposes is discussed. (author)

  13. Effect of microwave freeze drying on quality and energy supply in drying of barley grass.

    Science.gov (United States)

    Cao, Xiaohuang; Zhang, Min; Mujumdar, Arun S; Zhong, Qifeng; Wang, Zhushang

    2018-03-01

    Young barley grass leaves are well-known for containing the antioxidant substances flavonoid and chlorophyll. However, low product quality and energy efficiency exist with respect to the dehydration of barley grass leaves. To improve energy supply and the quality of barley grass, microwave heating instead of contact heat was applied for the freeze drying of barley grass at a pilot scale at 1, 1.5 and 2 W g -1 , respectively; After drying, energy supply and quality parameters of color, moisture content, chlorophyll, flavonoids, odors of dried barley grass were determined to evaluate the feasibility of the study. Microwave freeze drying (MFD) allowed a low energy supply and high contents of chlorophyll and flavonoids. A lightness value of 60.0, a green value of -11.5 and an energy supply of 0.61 kW h -1  g -1 were observed in 1.5 W g -1 MFD; whereas drying time (7 h) decreased by 42% compared to contact heating. Maximum content of flavonoid and chlorophyll was 11.7 and 12.8 g kg -1 barley grass. Microwave heating leads to an odor change larger than that for contact heating observed for the freeze drying of barley grass. MFD retains chlorophyll and flavonoids, as well as colors and odors of samples, and also decreases energy consumption in the freeze drying of barley grass. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  14. Response surface optimization of lyoprotectant for Lactobacillus bulgaricus during vacuum freeze-drying.

    Science.gov (United States)

    Chen, He; Chen, Shiwei; Li, Chuanna; Shu, Guowei

    2015-01-01

    The individual and interactive effects of skimmed milk powder, lactose, and sodium ascorbate on the number of viable cells and freeze-drying survival for vacuum freeze-dried powder formulation of Lactobacillus bulgaricus were studied by response surface methodology, and the optimal compound lyoprotectant formulations were gained. It is shown that skim milk powder, lactose, and sodium ascorbate had a significant impact on variables and survival of cultures after freeze-drying. Also, their protective abilities could be enhanced significantly when using them as a mixture of 28% w/v skim milk, 24% w/v lactose, and 4.8% w/v sodium ascorbate. The optimal freeze-drying survival rate and the number of viable cells of Lactobacillus bulgaricus were observed to be (64.41±0.02)% and (3.22±0.02)×10(11) colony-forming units (CFU)/g using the optimal compound protectants, which were very close to the expected values 64.47% and 3.28×10(11) CFU/g.

  15. Conservation of a medieval climbing stem by freeze-drying and resin impregnation

    International Nuclear Information System (INIS)

    Schaudy, R.; Slais, E.; Eibner, C.

    1985-12-01

    The conservation of a climbing stem originating from a medieval mining adit is described. The fragile wet object was preserved by a combined process consisting of freeze-drying after a polyethylene glycol bath and consecutive resin impregnation with curing by gamma irradiation. The whole conservation process took 1 year. The result is discussed. (Author)

  16. Optimization of Freeze Drying Conditions for Purified Pectinase from Mango (Mangifera indica cv. Chokanan Peel

    Directory of Open Access Journals (Sweden)

    Abdul Manap Mohd Yazid

    2012-03-01

    Full Text Available Response surface methodology (RSM along with central composite design (CCD was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan peel. The effect of pectinase content (−2.66, 62.66 mg/mL, Arabic gum (−1.21, 10.21%, w/v, and maltodextrin (0.73, 7.26%, w/v as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05 effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v of Arabic gum, and 4 (%, w/v of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL, yield (86.4% and storage stability (84.2% of encapsulated pectinase were achieved.

  17. Optimization of Freeze Drying Conditions for Purified Pectinase from Mango (Mangifera indica cv. Chokanan) Peel

    Science.gov (United States)

    Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd

    2012-01-01

    Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (−2.66, 62.66 mg/mL), Arabic gum (−1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05) effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved. PMID:22489134

  18. The impact of freeze-drying on microstructure and rehydration properties of carrot

    NARCIS (Netherlands)

    Voda, A.; Homan, N.; Witek, M.; Duijster, A.; Dalen, van G.; Sman, van der R.G.M.; Nijsse, J.; Vliet, van L.J.; As, van H.; Duynhoven, van J.P.M.

    2012-01-01

    The impact of freeze-drying, blanching and freezing rate pre-treatments on the microstructure and on the rehydration properties of winter carrots were studied by µCT, SEM, MRI and NMR techniques. The freezing rate determines the size of ice crystals being formed that leave pores upon drying. Their

  19. Production of freeze-dried yeast culture for the brewing of traditional sorghum beer, tchapalo.

    Science.gov (United States)

    N'Guessan, Florent K; Coulibaly, Hermann W; Alloue-Boraud, Mireille W A; Cot, Marlène; Djè, Koffi Marcellin

    2016-01-01

    Freeze-drying is a well-known dehydration method widely used to preserve microorganisms. In order to produce freeze-dried yeast starter culture for the brewing purpose of African sorghum beer, we tested protective agents (sucrose, glucose, glycerol) in combination with support materials (millet, maize, sorghum, and cassava flours) at 1:1 ratio (v/v). The yeast strains Saccharomyces cerevisiae F 12-7 and Candida tropicalis C 0-7 previously isolated from sorghum beer were used in a mixed culture at a ratio of 2:1 (C. tropicalis/S. cerevisiae). After the freeze-drying, the residual water contents were between 0.78 -2.27%, 0.55 -4.09%, and 0.40-2.61%, respectively, with sucrose, glucose and glycerol. The dried yeasts viabilities were between 4.0% and 10.6%. Among the protective agents used, sucrose was found to be the best protectant giving cell viabilities of 8.4-10.6%. Considering the support materials, millet flour was the best support after drying. When the freeze-dried yeast powders were stored at 4°C and room temperature (25-28°C) for up to 3 months, the survival rates were the highest with cassava flour as the support material.

  20. Preparation of interconnected highly porous polymeric structures by a replication and freeze-drying process

    NARCIS (Netherlands)

    Hou, Q.; Grijpma, Dirk W.; Feijen, Jan

    2003-01-01

    Three-dimensional degradable porous polymeric structures with high porosities (93-98%) and well-interconnected pore networks have been prepared by freeze-drying polymer solutions in the presence of a leachable template followed by leaching of the template. Templates of the pore network were prepared

  1. Are freeze drying and oven drying methods for trace metal determination in zoological specimens analytically sound

    International Nuclear Information System (INIS)

    Fourie, H.O.; Peisach, M.

    1976-01-01

    High specific activity radio-isotopes of chromium, zinc and selenium were used to label these elements accumulated by the oyster Crassostrea gigas. The retention of the metabolised forms of these elements during freeze-drying or oven drying at 50, 90, 105 and 120 deg C was studied. Observed losses question the accuracy of these analytical procedures. (author)

  2. Fabrication of Li2TiO3 pebbles by a freeze drying process

    International Nuclear Information System (INIS)

    Lee, Sang-Jin; Park, Yi-Hyun; Yu, Min-Woo

    2013-01-01

    Li 2 TiO 3 pebbles were successfully fabricated by using a freeze drying process. The Li 2 TiO 3 slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li 2 TiO 3 pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined

  3. Theoretical and practical aspects of aroma retention in spray drying and freeze drying

    NARCIS (Netherlands)

    Coumans, W.J.; Kerkhof, P.J.A.M.; Bruin, S.

    1994-01-01

    A review with 75 refs. on aroma loss in slab drying, spray drying and freeze drying. For many food products the presence of volatile aroma components is a prime quality feature. Upon drying part of these components may be lost, leading to unbalanced flavor patterns in the reconstituted product. The

  4. Effect of Freeze-Drying on the Antioxidant Compounds and Antioxidant Activity of Selected Tropical Fruits

    Science.gov (United States)

    Shofian, Norshahida Mohamad; Hamid, Azizah Abdul; Osman, Azizah; Saari, Nazamid; Anwar, Farooq; Dek, Mohd Sabri Pak; Hairuddin, Muhammad Redzuan

    2011-01-01

    The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05) higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05) but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested. PMID:21845104

  5. Radiolysis and radiosterilization of drugs

    International Nuclear Information System (INIS)

    Zeegers, F.; Crucq, A.S.; Gibella, M.; Tilquin, B.

    1993-01-01

    Can the absence of increased toxicological danger in irradiated foods be applied with confidence to drugs. The World Health Organization stated that up to 10 kGy there is no toxicological hazard. However, even if the irradiated drugs meet official standards, it would have to be established that any traces of radiolysis product formed are not toxic. All the tests from PHARMACOPEIA are not appropriate to detect the radiolysis and new physicochemical tests have to be used. Chromatographic detection of the radiosterilization of antibiotics may be advantageously used when the pharmaceuticals are not radio-resistant. The main obstacle to practical application is the low sensitivity of the detectors in liquid-liquid chromatography, a re-irradiation of the suspected samples will be necessary after preliminary chromatographic studies. 8 figs

  6. Economic aspects of radiosterilization; Aspekty ekonomiczne sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The economic analysis of radiosterilization have been done. The costs have been estimated on the example of Electron Accelerator Irradiation Plant for Radiosterilization working in Institute of Nuclear Chemistry and Technology, Warsaw. 3 tabs.

  7. Spray freeze drying to produce a stable Delta(9)-tetrahydrocannabinol containing inulin-based solid dispersion powder suitable for inhalation

    NARCIS (Netherlands)

    van Drooge, Dirk-Jan; Hinrichs, Wouter L J; Dickhoff, Bastiaan H J; Elli, Marco N A; Visser, Marinella R; Zijlstra, Gerrit S; Frijlink, Henderik W

    2005-01-01

    The purpose of this study is to investigate whether spray freeze drying produces an inhalable solid dispersion powder in which Delta(9)-tetrahydrocannabinol (THC) is stabilised. Solutions of THC and inulin in a mixture of tertiary butanol (TBA) and water were spray freeze dried. Drug loads varied

  8. Preparation and Characterization of Solid Dispersions of Artemether by Freeze-Dried Method

    Directory of Open Access Journals (Sweden)

    Muhammad Tayyab Ansari

    2015-01-01

    Full Text Available Solid dispersions of artemether and polyethylene glycol 6000 (PEG6000 were prepared in ratio 12 : 88 (group-1. Self-emulsified solid dispersions of artemether were prepared by using polyethylene glycol 6000, Cremophor-A25, olive oil, Transcutol, and hydroxypropyl methylcellulose (HPMC in ratio 12 : 75 : 5 : 4 : 2 : 2, respectively (group-2. In third group, only Cremophor-A25 was replaced with Poloxamer 188 compared to group-2. The solid dispersions and self-emulsified solid dispersions were prepared by physical and freeze dried methods, respectively. All samples were characterized by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimeter, scanning electron microscopy, and solubility, dissolution, and stability studies. X-ray diffraction pattern revealed artemether complete crystalline, whereas physical mixture and freeze-dried mixture of all three groups showed reduced peak intensities. In attenuated total reflectance Fourier transform infrared spectroscopy spectra, C–H stretching vibrations of artemether were masked in all prepared samples, while C–H stretching vibrations were representative of polyethylene glycol 6000, Cremophor-A25, and Poloxamer 188. Differential scanning calorimetry showed decreased melting endotherm and increased enthalpy change (ΔH in both physical mixture and freeze-dried mixtures of all groups. Scanning electron microscopy of freeze-dried mixtures of all samples showed glassy appearance, size reduction, and embedment, while their physical mixture showed size reduction and embedment of artemether by excipients. In group-1, solubility was improved up to 15 times, whereas group-2 showed up to 121 times increase but, in group-3, when Poloxamer 188 was used instead of Cremophor-A25, solubility of freeze-dried mixtures was increased up to 135 times. In fasted state simulated gastric fluid at pH 1.6, the dissolution of physical

  9. In vitro evaluation of demineralized freeze-dried bone allograft in combination with enamel matrix derivative.

    Science.gov (United States)

    Miron, Richard J; Bosshardt, Dieter D; Laugisch, Oliver; Dard, Michel; Gemperli, Anja C; Buser, Daniel; Gruber, Reinhard; Sculean, Anton

    2013-11-01

    Preclinical and clinical studies suggest that a combination of enamel matrix derivative (EMD) with demineralized freeze-dried bone allograft (DFDBA) may improve periodontal wound healing and regeneration. To date, no single study has characterized the effects of this combination on in vitro cell behavior. The aim of this study is to test the ability of EMD to adsorb to the surface of DFDBA particles and determine the effect of EMD coating on downstream cellular pathways such as adhesion, proliferation, and differentiation of primary human osteoblasts and periodontal ligament (PDL) cells. DFDBA particles were precoated with EMD or human blood and analyzed for protein adsorption patterns via scanning electron microscopy. Cell attachment and proliferation were quantified using a commercial assay. Cell differentiation was analyzed using real-time polymerase chain reaction for genes encoding Runx2, alkaline phosphatase, osteocalcin, and collagen 1α1, and mineralization was assessed using alizarinred staining. Analysis of cell attachment revealed no significant differences among control, blood-coated, and EMD-coated DFDBA particles. EMD significantly increased cell proliferation at 3 and 5 days after seeding for both osteoblasts and PDL cells compared to control and blood-coated samples. Moreover, there were significantly higher messenger ribonucleic acid levels of osteogenic differentiation markers, including collagen 1α1, alkaline phosphatase, and osteocalcin, in osteoblasts and PDL cells cultured on EMD-coated DFDBA particles at 3, 7, and 14 days. The results suggest that the addition of EMD to DFDBA particles may influence periodontal regeneration by stimulating PDL cell and osteoblast proliferation and differentiation.

  10. Microbiological evaluation of anatomical organs submitted to glycerinization and freeze-drying techniques

    Directory of Open Access Journals (Sweden)

    Marianna Justo

    2016-06-01

    Full Text Available Alternatives conservation techniques are being requested with the proposal of formaldehyde substitution. Formaldehyde results in excessive anatomical specimens' weight and it can cause serious health problems to the manipulator, such as cancer. However, it provides an efficient germicide and fungicide action depending on concentration. The substitute techniques are glicerinization and freeze-drying which have advantages such as non-production of smells, lightness of the organs and dispenses the use of fixatives in conservation. As well as both intrinsic and extrinsic factors interfere in microbial growth, microbiological analyzes are essential to detect possible deteriorative microorganisms in organs and concluding effectively the technique used. Formalinized, glycerinated and freeze-drying organs were collected in three different times which were intercalated by two months, except formalinization that had one evaluation. The procedure required the use of sterilized swabs wetted in peptone water and molds measuring 5,0 cm x 10,0 cm positioned on two different piece's local resulting in 100 cm2 of area, to spread plate of total moulds, mesophiles (except in freeze-drying, psychrophilic (only in freeze-drying and Pseudomonas sp (except in formalinization. All the plates were counted and compared between each technique's evaluations by variance analyzes. Both alternatives techniques resulted in zero or in very low microbial quantity to cause health problems as well as it preserve pieces morphology. All values of all analyzes resulted below 1/ml, showing that glicerinization and freeze-drying techniques are so as efficient as formaldehyde. Keywords: Organs conservation, Anatomical techniques, Microbiology, Microbial growth

  11. Freeze-dried bone allografts sterilized with gamma radiation and the clinical use in harelip

    International Nuclear Information System (INIS)

    Luna Z, D.; Reyes F, M. L.; Diaz M, I.; Cruz A, L. C.; Vazquez R, M. A.

    2010-10-01

    Bone for transplant is part of the musculoskeletal tissue join with fascia lat, tendon, ligament and cartilage. Bone is formed by cells (osteocytes, osteoblasts and osteoclasts) and extracellular matrix formed mainly by collagen and hydroxyapatite, which gives strength and elasticity to the bone. The bone function in the body is to move, support, organs protection, production of blood cells and store minerals. The musculoskeletal tissue is processed in specialized tissue banks using gamma radiation of cobalt-60 for sterilization at 25 kGy doses at very low temperature or at room temperature, getting tissues with high quality for clinical applications in injured patients. The process of the bone for transplants varies depend on the size and the surgeon likes, nevertheless in general the large ones are preserved at low temperature (-80 C), meanwhile the short ones are freeze-dried preserved. The musculoskeletal diseases represent the most common physical incapacity, which affect million of people around the world. Due to the human body has 206 bones, during a bone injury each bone can be replaced or repaired with several devices, in general the surgeon goes to a specialized tissue banks, to get the bone, due to the high bone quantity on the body and the number of bone injuries and diseases, the bone is the most transplanted around the world only behind the blood. The bone can be processed in several sizes and shapes, one of these is bone powder from allograft, which is used over all for bone filling, this can be take advantage for cleft lip and palate defects, which is a birth defect, this can affect the way the child's face looks, it can also lead to problems with eating, talking and ear infections. The description of the bone powder process is presented and the clinical use of this powder in several pediatric patients for cleft lip and palate defects is described. (Author)

  12. Freeze-dried bone allografts sterilized with gamma radiation and the clinical use in harelip

    Energy Technology Data Exchange (ETDEWEB)

    Luna Z, D.; Reyes F, M. L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Diaz M, I.; Cruz A, L. C. [Centro Estatal de Trasplantes del Estado de Mexico, Pablo Sidar No. 602, Col. Universidad, Toluca 50130, Estado de Mexico (Mexico); Vazquez R, M. A., E-mail: daniel.luna@inin.gob.m [Centro de Especialidades Odontologicas, Instituto Materno Infantil del Estado de Mexico, Paseo Colon esquina Felipe Angeles s/n, Col. Villa Hogar, Toluca 50170, Estado de Mexico (Mexico)

    2010-10-15

    Bone for transplant is part of the musculoskeletal tissue join with fascia lat, tendon, ligament and cartilage. Bone is formed by cells (osteocytes, osteoblasts and osteoclasts) and extracellular matrix formed mainly by collagen and hydroxyapatite, which gives strength and elasticity to the bone. The bone function in the body is to move, support, organs protection, production of blood cells and store minerals. The musculoskeletal tissue is processed in specialized tissue banks using gamma radiation of cobalt-60 for sterilization at 25 kGy doses at very low temperature or at room temperature, getting tissues with high quality for clinical applications in injured patients. The process of the bone for transplants varies depend on the size and the surgeon likes, nevertheless in general the large ones are preserved at low temperature (-80 C), meanwhile the short ones are freeze-dried preserved. The musculoskeletal diseases represent the most common physical incapacity, which affect million of people around the world. Due to the human body has 206 bones, during a bone injury each bone can be replaced or repaired with several devices, in general the surgeon goes to a specialized tissue banks, to get the bone, due to the high bone quantity on the body and the number of bone injuries and diseases, the bone is the most transplanted around the world only behind the blood. The bone can be processed in several sizes and shapes, one of these is bone powder from allograft, which is used over all for bone filling, this can be take advantage for cleft lip and palate defects, which is a birth defect, this can affect the way the child's face looks, it can also lead to problems with eating, talking and ear infections. The description of the bone powder process is presented and the clinical use of this powder in several pediatric patients for cleft lip and palate defects is described. (Author)

  13. Healthy offspring from freeze-dried mouse spermatozoa held on the International Space Station for 9 months.

    Science.gov (United States)

    Wakayama, Sayaka; Kamada, Yuko; Yamanaka, Kaori; Kohda, Takashi; Suzuki, Hiromi; Shimazu, Toru; Tada, Motoki N; Osada, Ikuko; Nagamatsu, Aiko; Kamimura, Satoshi; Nagatomo, Hiroaki; Mizutani, Eiji; Ishino, Fumitoshi; Yano, Sachiko; Wakayama, Teruhiko

    2017-06-06

    If humans ever start to live permanently in space, assisted reproductive technology using preserved spermatozoa will be important for producing offspring; however, radiation on the International Space Station (ISS) is more than 100 times stronger than that on Earth, and irradiation causes DNA damage in cells and gametes. Here we examined the effect of space radiation on freeze-dried mouse spermatozoa held on the ISS for 9 mo at -95 °C, with launch and recovery at room temperature. DNA damage to the spermatozoa and male pronuclei was slightly increased, but the fertilization and birth rates were similar to those of controls. Next-generation sequencing showed only minor genomic differences between offspring derived from space-preserved spermatozoa and controls, and all offspring grew to adulthood and had normal fertility. Thus, we demonstrate that although space radiation can damage sperm DNA, it does not affect the production of viable offspring after at least 9 mo of storage on the ISS.

  14. Comparison of drying characteristic and uniformity of banana cubes dried by pulse-spouted microwave vacuum drying, freeze drying and microwave freeze drying.

    Science.gov (United States)

    Jiang, Hao; Zhang, Min; Mujumdar, Arun S; Lim, Rui-Xin

    2014-07-01

    To overcome the flaws of high energy consumption of freeze drying (FD) and the non-uniform drying of microwave freeze drying (MFD), pulse-spouted microwave vacuum drying (PSMVD) was developed. The results showed that the drying time can be dramatically shortened if microwave was used as the heating source. In this experiment, both MFD and PSMVD could shorten drying time by 50% as compared to the FD process. Depending on the heating method, MFD and PSMVD dried banana cubes showed trends of expansion while FD dried samples demonstrated trends of shrinkage. Shrinkage also brought intensive structure and highest fracturability of all three samples dried by different methods. The residual ascorbic acid content of PSMVD dried samples can be as high as in FD dried samples, which were superior to MFD dried samples. The tests confirmed that PSMVD could bring about better drying uniformity than MFD. Besides, compared with traditional MFD, PSMVD can provide better extrinsic feature, and can bring about improved nutritional features because of the higher residual ascorbic acid content. © 2013 Society of Chemical Industry.

  15. The effect of variety and maturity on the quality of freeze-dried carrots. The effect of microwave blanching on the nutritional and textural quality of freeze-dried spinach

    Science.gov (United States)

    1979-01-01

    Using carrots, the quality of freeze-dried products was studied to determine the optimum varieties and maturation stages for quality attributes such as appearance, flavor, texture, and nutritive value. The quality of freeze-dried carrots is discussed in terms of Gardner color, alcohol insoluble solids, viscosity, and core/cortex ratio. Also, microwave blanching of freeze-dried spinach was studied to determine vitamin interrelationships, anatomical changes, and oxidative deteriorations in terms of preprocessing microwave treatments. Statistical methods were employed in the gathering of data and interpretation of results in both studies.

  16. Dynamic Low-Vacuum Scanning Electron Microscope Freeze Drying Observation for Fresh Water Algae

    International Nuclear Information System (INIS)

    Mohsen, H.T.; Ghaly, W.A.; Zahran, N.F.; Helal, A.I.

    2010-01-01

    A new perpetration method for serving in dynamic examinations of the fresh water algae is developed in connection with the Low-Vacuum Scanning Electron Microscope (LV-SEM) freeze drying technique. Specimens are collected from fresh water of Ismailia channel then transferred directly to freeze by liquid nitrogen and dried in the chamber of the scanning electron microscope in the low vacuum mode. Scanning electron micrographs revealed that the drying method presented the microstructure of algae. Dehydration in a graded ethanol series is not necessary in the new method. Dried algae specimen is observed in SEM high vacuum mode after conductive coating at higher resolution. Low-vacuum SEM freeze drying technique is a simple, time-saving and reproducible method for scanning electron microscopy that is applicable to various aquatic microorganisms covered with soft tissues.

  17. A Dynamic Design Space for Primary Drying During Batch Freeze-Drying

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F C; Van Bockstal, Pieter Jan; Nopens, Ingmar

    2016-01-01

    Biopharmaceutical products are emerging within the pharmaceutical industry. However, biopharmaceuticals are often unstable in aqueous solution. Freeze-drying (lyophilisation) is the preferred method to achieve a stable product with an increased shelf-life. During batch freeze-drying, there are only...... two adaptable process variables, i.e. the shelf temperature and the pressure in the drying chamber. The value of both should be optimized, preferably in a dynamic way, to minimise the primary drying time while respecting process and equipment constraints and ensuring end product quality. A mechanistic...... model is used to determine the optimal values for the adaptable variables, hereby accounting for the uncertainty in all involved model parameters. A dynamic Design Space was constructed with a risk of failure acceptance level of 0.01%, i.e. a 'zero-failure' situation. Even for a risk of failure of 0...

  18. Development of freeze-dried miyeokguk, Korean seaweed soup, as a space food sterilized by irradiation

    International Nuclear Information System (INIS)

    Lee, Ju Yeon; Song, Beom Seok; Park, Jin Gyu; Cho, Won Jun; Kim, Jae Hun; Yoon Yo Han; Choi, Jong Il; Lee, Ju Woon

    2010-01-01

    This study was conducted to evaluate the microbial (Total aerobic count, Coliform, Coagulase positive Staphylococci, Salmonella, Yeast/Mold, Escherichia coli, Bacillus cereus), Hunter' color values (L*, a*, b*) and organoleptic quality of freeze-dried Miyeokguk, Korean seaweed soup in space food, Bacillus cereus was 1 log level while not detected in the sample irradiated at 10 kGy. Hunter's color values of the samples irradiated less than 10 kGy was not significantly different (p>0.05). The sensory evaluation result showed that the preference scores in all the sensory properties decreased when it was irradiated over 10 kGy, but sensory score of less than 10 kGy samples was similar in all terms. Therefore, it was considered that gamma irradiation at 10 kGy was enough to sterilize the freeze-dried Miyeokguk without deterioration of sensory quality

  19. Characterization of freeze-dried egg melange long stored after irradiation

    International Nuclear Information System (INIS)

    Bakalivanov, Stefan; Tsvetkova, Eli; Bakalivanova, Todorka; Tsvetkov, Tsvetan; Kaloyanov, Nikolay; Grigorova, Stoyanka; Alexieva, Vanja

    2008-01-01

    During the 4-year period of storage at room temperature of the freeze-dried (control group) and the freeze-dried and gamma-irradiated (2.0 and 3.5 kGy) whole hen's egg melange, no significant changes were found into the sensory and functional characteristics till the 28th month. The change in the number of SH groups was not unidirectional up to the 28th month and then it started to decrease in all investigated samples. During the entire period of investigation the amount of malondialdehyde in all three groups of egg melange was considerably below the allowed limit for foodstuffs. The most significant fractions of the protein spectra showed a general tendency of decrease during the storage

  20. Development of freeze-dried miyeokguk, Korean seaweed soup, as a space food sterilized by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju Yeon [Chonbuk National University, Jeonju (Korea, Republic of); Song, Beom Seok; Park, Jin Gyu; Cho, Won Jun; Kim, Jae Hun; Yoon Yo Han; Choi, Jong Il; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-03-15

    This study was conducted to evaluate the microbial (Total aerobic count, Coliform, Coagulase positive Staphylococci, Salmonella, Yeast/Mold, Escherichia coli, Bacillus cereus), Hunter' color values (L*, a*, b*) and organoleptic quality of freeze-dried Miyeokguk, Korean seaweed soup in space food, Bacillus cereus was 1 log level while not detected in the sample irradiated at 10 kGy. Hunter's color values of the samples irradiated less than 10 kGy was not significantly different (p>0.05). The sensory evaluation result showed that the preference scores in all the sensory properties decreased when it was irradiated over 10 kGy, but sensory score of less than 10 kGy samples was similar in all terms. Therefore, it was considered that gamma irradiation at 10 kGy was enough to sterilize the freeze-dried Miyeokguk without deterioration of sensory quality.

  1. [A case of orchitis following vaccination with freeze-dried live attenuated mumps vaccine].

    Science.gov (United States)

    Suzuki, Masayasu; Takizawa, Akitoshi; Furuta, Akira; Yanada, Shuichi; Iwamuro, Shinya; Tashiro, Kazuya

    2002-05-01

    In Japan, freeze-dried live attenuated mumps vaccine has been used optionally since 1981. The effectiveness of mumps vaccination has been established by worldwide research since 1971. On the other hand, because of it's live activity several untoward effects have been reported. Vaccination-related mumps orchitis is a rare adverse effect of mumps vaccine. Only 9 cases of vaccination-related mumps orchitis have been reported in Japan. We describe a case of orchitis following mumps vaccination in adolescence. A 16 years-old male has admitted because of acute orchitis with high fever and painful swelling of right testis. The patient had received vaccination with freeze-dried live attenuated mumps vaccine 16 days before admission. After admission, the bed-rest had completely relieved the symptoms on 6th hospital day. The impaired testis has maintained normal size and consistency 6 months after discharge.

  2. Development of a freeze-drying process of waste-solution, 2

    International Nuclear Information System (INIS)

    Kondo, Isao; Kawasaki, Takeshi

    1988-01-01

    The waste solution treatment process in Plutonium Conversion Development Facility (PCDF) consists of Evaporation-Condensation and Neutrazation-Agglometation-Precipitation process, which produces the distillate as recovered acid at first step and separates Pu-U element from condenced solution at second step. This process needs many stages to get high decontamination efficiency and then the Evaporator is in very corrosive state because the nitric acid solution is heated over 100 degrees C to be evaporated. So, in PCDF, it was started the development of Freeze-Drying process to waste solution treatment. This process is suitable for a little quantity of the solution including nitric acid as produced in the Microwave Heating method. Moreover the process has high decontamination efficiency and has good performance of equipment. The result of the cold test of Freeze-Drying process with nitric acid is discribed in this paper. (author)

  3. Distribution of Vapor Pressure in the Vacuum Freeze-Drying Equipment

    Directory of Open Access Journals (Sweden)

    Shiwei Zhang

    2012-01-01

    Full Text Available In the big vacuum freeze-drying equipment, the drying rate of materials is uneven at different positions. This phenomenon can be explained by the uneven distribution of vapor pressure in chamber during the freeze-drying process. In this paper, a mathematical model is developed to describe the vapor flow in the passageways either between material plates and in the channel between plate groups. The distribution of vapor pressure along flow passageway is given. Two characteristic factors of passageways are defined to express the effects of structural and process parameters on vapor pressure distribution. The affecting factors and their actions are quantitatively discussed in detail. Two examples are calculated and analyzed. The analysis method and the conclusions are useful to estimate the difference of material drying rate at different parts in equipment and to direct the choice of structural and process parameters.

  4. Recovery and storage method for radioactive iodine by vacuum freeze-drying

    International Nuclear Information System (INIS)

    Otsuka, Katsuyuki; Ouchi, Hitoshi; Suzuki, Toru.

    1990-01-01

    After scrubbing off-gas formed in a re-processing process for spent nuclear fuels, scrubbing liquids after use are subjected, as they are or with addition of additives, to a precipitating treatment. Then, liquid wastes containing radioactive iodine was subjected to freeze-drying treatment by freeze-drying under vacuum to recover radioactive iodine as iodine compounds. Off-gas scrubbing is conducted by using a sodium hydroxide solution and copper or silver ions may be added as additives in the precipitating treatment. Recovered iodine compounds containing radioactive iodine are solidified, either directly or after formulating into a composition of naturally existing iodine-containing ores by means of high pressure pressing into ores. This can prevent radioactive iodine 1 29I of long half-decay time from diffusing into the circumference and store the radioactive iodine stably for a long period of time. (T.M.)

  5. Protection of fish oil from oxidation by microencapsulation using freeze-drying techniques

    DEFF Research Database (Denmark)

    Heinzelmann, K.; Franke, K.; Jensen, Benny

    2000-01-01

    (N-3)-Polyunsaturated fatty acids (PUFAs) reduce the risk of coronary heart disease. Cold sea water plankton and plankton- consuming fish are known sources of (n-3)-PUFAs. Enriching normal food components with fish oil is a tool for increasing the intake of (n-3)-PUFAs. Due to the high sensitivity...... different freezing techniques and subsequently freeze-dried. Several parameters regarding formulation and process (addition of antioxidants to the fish oil, use of carbohydrates, homogenisation and freezing conditions, initial freeze-drying temperature, grinding) were varied to evaluate their influence...... on the oxidative stability of dried microencapsulated fish oil. The shelf life of the produced samples was determined by measuring the development of volatile oxidation products vs. storage time. It could be shown that the addition of antioxidants to fish oil was necessary to produce dried microencapsulated fish...

  6. Spray freeze-dried nanofibrillated cellulose aerogels with thermal superinsulating properties.

    Science.gov (United States)

    Jiménez-Saelices, Clara; Seantier, Bastien; Cathala, Bernard; Grohens, Yves

    2017-02-10

    Nanofibrillated cellulose (NFC) aerogels were prepared by spray freeze-drying (SFD). Their structural, mechanical and thermal insulation properties were compared to those of NFC aerogels prepared by conventional freeze-drying (CFD). The purpose of this investigation is to develop superinsulating bioaerogels by reducing their pore size. Severe reduction of the aerogel pore size and skeleton architecture were observed by SEM, aerogels prepared by SFD method show a fibril skeleton morphology, which defines a mesoporous structure. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, the thermal insulation properties were significantly improved for SFD materials compared to CFD aerogel, reaching values of thermal conductivity as low as 0.018W/(mK). Moreover, NFC aerogels have a thermal conductivity below that of air in ambient conditions, making them one of the best cellulose based thermal superinsulating material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Electronic Nose Characterization of the Quality Parameters of Freeze-Dried Bacteria

    Science.gov (United States)

    Capuano, R.; Santonico, M.; Martinelli, E.; Paolesse, R.; Passot, S.; Fonseca, F.; Cenard, S.; Trelea, C.; Di Natale, C.

    2011-09-01

    Freeze-drying is the method of choice for preserving heat sensitive biological products such as microorganisms. The development of a fast analytical method for evaluating the properties of the dehydrated bacteria is then necessary for a proper utilization of the product in several food processes. In this paper, dried bacteria headspace is analyzed by a GC-MS and an electronic nose. Results indicate that headspace contains enough information to assess the products quality.

  8. Methylprednisolone and its related substances in freeze-dried powders for injections

    OpenAIRE

    LJILJANA SOLOMUN; SVETLANA IBRIĆ; VLATKA VAJS; IVAN VUČKOVIĆ; ZORICA VUJIĆ

    2010-01-01

    In this work, the behavior of the active pharmaceutical substances methylprednisolone (in a form of methylprednisolone sodium succinate) in finished pharmaceutical dosage form, i.e., freeze-dried powder for injections was examined. The goal was to evaluate the chemical stabilities of methyl-prednisolone sodium succinate packaged in a dual chamber vial, as a specific container closure system. The effect of different parameters: temperature, moisture and light were monitored. The method propose...

  9. Optimization of protectant, salinity and freezing condition for freeze-drying preservation of Edwardsiella tarda

    Science.gov (United States)

    Yu, Yongxiang; Zhang, Zheng; Wang, Yingeng; Liao, Meijie; Li, Bin; Xue, Liangyi

    2017-10-01

    Novel preservation condition without ultra-low temperature is needed for the study of pathogen in marine fishes. Freeze-drying is such a method usually used for preservation of terrigenous bacteria. However, studies using freeze-drying method to preserving marine microorganisms remain very limited. In this study, we optimized the composition of protectants during the freeze-drying of Edwardsiella tarda, a fish pathogen that causes systemic infection in marine fishes. We found that the optimal composition of protectant mixture contained trehalose (8.0%), skim milk (12.0%), sodium citrate (2.0%), serum (12.0%) and PVP (2.0%). Orthogonal and interaction analyses demonstrated the interaction between serum and skim milk or sodium citrate. The highest survival rate of E. tarda was observed when the concentration of NaCl was 10.0, 30.0 and between 5.0 and 10.0 g L-1 for preparing TSB medium, E. tarda suspension and protectant mixture, respectively. When E. tarda was frozen at -80°C or -40°C for 6 h, its survival rate was higher than that under other tested conditions. Under the optimized conditions, when the protectant mixture was used during freeze-drying process, the survival rate (79.63%-82.30%) of E. tarda was significantly higher than that obtained using single protectant. Scanning electron microscopy (SEM) image indicated that E. tarda was embedded in thick matrix with detectable aggregation. In sum, the protectant mixture may be used as a novel cryoprotective additive for E. tarda.

  10. X-ray microanalysis of freeze-dried and frozen-hydrated cryosections

    International Nuclear Information System (INIS)

    Zierold, K.

    1988-01-01

    The elemental composition and the ultrastructure of biological cells were studied by scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray microanalysis. The preparation technique involves cryofixation, cryoultramicrotomy, cryotransfer, and freeze-drying of samples. Freeze-dried cryosections 100-nm thick appeared to be appropriate for measuring the distribution of diffusible elements and water in different compartments of the cells. The lateral analytical resolution was less than 50 nm, depending on ice crystal damage and section thickness. The detection limit was in the range of 10 mmol/kg dry weight for all elements with an atomic number higher than 12; for sodium and magnesium the detection limits were about 30 and 20 mmol/kg dry weight, respectively. The darkfield intensity in STEM is linearly related to the mass thickness. Thus, it becomes possible to measure the water content in intracellular compartments by using the darkfield signal of the dry mass remaining after freeze-drying. By combining the X-ray microanalytical data expressed as dry weight concentrations with the measurements of the water content, physiologically more meaningful wet weight concentrations of elements were determined. In comparison to freeze-dried cryosections frozen-hydrated sections showed poor contrast and were very sensitive against radiation damage, resulting in mass loss. The high electron exposure required for recording X-ray spectra made reproducible microanalysis of ultrathin (about 100-nm thick) frozen-hydrated sections impossible. The mass loss could be reduced by carbon coating; however, the improvement achieved thus far is still insufficient for applications in X-ray microanalysis. Therefore, at present only bulk specimens or at least 1-micron thick sections can be used for X-ray microanalysis of frozen-hydrated biological samples

  11. [A case of freeze-dried gas gangrene antitoxin for the treatment of Clostridium perfringens sepsis].

    Science.gov (United States)

    Yoshida, Juichiro; Nakamura, Hideki; Yamada, Shinya; Sekoguchi, Satoru; Suzuki, Takahiro; Tomatsuri, Naoya; Sato, Hideki; Okuyama, Yusuke; Kimura, Hiroyuki; Yoshida, Norimasa

    2015-02-01

    A 66-year-old man was admitted to our hospital with high fever. We diagnosed a gas-containing liver abscess and performed percutaneous abscess drainage. However, 15 hours after admission, he developed massive intravascular hemolysis and acidosis. Sepsis due to Clostridium perfringens was suspected and we treated the patient intensively with multidisciplinary approaches, including antibiotics, mechanical ventilation, and renal replacement therapy. Furthermore, we administered freeze-dried gas gangrene antitoxin. Despite intensive care, the patient died 43 hours after admission.

  12. Freeze dried bone allografts in dental and maxillofacial reconstructive surgery - experience in Malaysia

    International Nuclear Information System (INIS)

    Abd Rani Samsudin; Meor Zaidi Meor Kamal

    1999-01-01

    The utilisation of vascularised and free bone autografts remain the goal standard in maxillofacial reconstructive surgery in Malaysia, but the use of freeze dried bone allograft is still widely practiced in many centres with variable results. This study evaluate the effectiveness and clinical efficacy of using radiation sterilised freeze dried bone allografts in oral and maxillofacial reconstructive surgery. The bone grafts were prepared at the Malaysian National Tissue Bank. Seventy eight patients who had undergone oral and Maxillofacial surgical procedures with reconstruction using bone allografts were included in this study. 50 patients were male and 28 patients were female and their age ranged from 14 to 75 years. Forty two patients underwent enucleation of benign cystic lesions in the jaws, 15 patients underwent repair of orbital floor fractures, 6 patients of jaw fractures with partial loss of bone while 8 patients underwent augmentation of depressed cheek bone. Another 4 patients had partial resection of the mandible because of cancer and 3 patients had facial osteotomies. A follow up period of 12 months up to 4 years was carried out. The patients were assessed both clinically and radiologically throughout their follow up visits. Clinical assessment showed no evidence of rejection of the implanted freeze dried allografts. Bone allografts implanted as inlay grafts demonstrated a better clinical performance than onlay grafts and the poorest results were obtained following bridging bony defects in the jaws. Radiation sterilised freeze dried bone allografts produced at the Malaysian National Tissue Bank are bio-compatible, functional, and provide predictable results when applied to selected areas of the facial skeleton

  13. Viability of G4 after Spray-Drying and Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Stephenie Wong

    2010-01-01

    Full Text Available Viability of Bifidobacterium pseudocatenulatum G4 following spray-drying and freeze-drying in skim milk was evaluated. After spray-drying, the strain experienced over 99% loss in viability regardless of the air outlet temperature (75 and 85 °C and the heat-adaptation temperature (45 and 65 °C, 30 min. The use of heat-adaptation treatment to improve the thermotolerance of this strain was ineffective. On the other hand, the strain showed a superior survival at 71.65%–82.07% after freeze-drying. Viable populations of 9.319–9.487 log 10 cfu/g were obtained when different combinations of skim milk and sugar were used as cryoprotectant. However, the addition of sugars did not result in increased survival during the freeze-drying process. Hence, 10% (w/v skim milk alone is recommended as a suitable protectant and drying medium for this strain. The residual moisture content obtained was 4.41% ± 0.44%.

  14. Water-Hydrogel Binding Affinity Modulates Freeze-Drying-Induced Micropore Architecture and Skeletal Myotube Formation.

    Science.gov (United States)

    Rich, Max H; Lee, Min Kyung; Marshall, Nicholas; Clay, Nicholas; Chen, Jinrong; Mahmassani, Ziad; Boppart, Marni; Kong, Hyunjoon

    2015-08-10

    Freeze-dried hydrogels are increasingly used to create 3D interconnected micropores that facilitate biomolecular and cellular transports. However, freeze-drying is often plagued by variance in micropore architecture based on polymer choice. We hypothesized that water-polymer binding affinity plays a significant role in sizes and numbers of micropores formed through freeze-drying, influencing cell-derived tissue quality. Poly(ethylene glycol)diacrylate (PEGDA) hydrogels with alginate methacrylate (AM) were used due to AM's higher binding affinity for water than PEGDA. PEGDA-AM hydrogels with larger AM concentrations resulted in larger sizes and numbers of micropores than pure PEGDA hydrogels, attributed to the increased mass of water binding to the PEGDA-AM gel. Skeletal myoblasts loaded in microporous PEGDA-AM hydrogels were active to produce 3D muscle-like tissue, while those loaded in pure PEGDA gels were localized on the gel surface. We propose that this study will be broadly useful in designing and improving the performance of various microporous gels.

  15. Freeze Drying Improves the Shelf-Life of Conductive Polymer Modified Neural Electrodes

    Directory of Open Access Journals (Sweden)

    Himadri S. Mandal

    2015-08-01

    Full Text Available Coating microelectrodes with conductive polymer is widely recognized to decrease impedance and improve performance of implantable neural devices during recording and stimulation. A concern for wide-spread use of this approach is shelf-life, i.e., the electrochemical stability of the coated microelectrodes prior to use. In this work, we investigated the possibility of using the freeze-drying process in order to retain the native low impedance state and, thereby, improve the shelf-life of conductive polymer poly(3,4-ethylenedioxythiophene (PEDOT-PSS modified neural electrodes. Control PEDOT-PSS coated microelectrodes demonstrated a significant increase in impedance at 1 kHz after 41–50 days of room temperature storage. Based on equivalent circuit modeling derived from electrochemical impedance spectroscopy, this increase in impedance could be largely attributed to a decrease in the interfacial capacitance consistent with a collapse and closing of the porous structure of the polymeric coating. Time-dependent electrochemical impedance measurements revealed higher stability of the freeze-dried coated microelectrodes compared to the controls, such that impedance values after 41–50 days appeared to be indistinguishable from the initial levels. This suggests that freeze drying PEDOT-PSS coated microelectrodes correlates with enhanced electrochemical stability during shelf storage.

  16. Synthesis, processing behavior, and characterization of bismuth superconductors using freeze dried nitrate precursors

    International Nuclear Information System (INIS)

    Coppa, N.V.; Hults, W.L.; Smith, J.L.; Brynestad, J.

    1994-01-01

    The synthesis of Bi 2-x Pb x Sr 2 Ca 2 Cu 3 O 10 (Bi2223) powders from a freeze dried nitrate precursor is reported here. We examine the composition and morphology of the precursor material, describe the chemistry and kinetics of product formation, and evaluate the phase composition and superconducting properties of the products. A nitrate solution containing the appropriate ratio of cations was rapidly frozen and then freeze dried at low temperatures to form an atomic mixture of the component salts. The thermal processing of the freeze dried material consisted of three steps: (i) dehydration, (ii) denitration, and (iii) solid state reaction to form the Bi2223 superconducting product. Calcium substituted bismuthates and strontium-substituted calcium cuprate, not Bi2201, are the intermediates between the nitrates and the superconducting products. These highly disordered phases rapidly transform into Bi2212 or Bi2223 at higher temperatures (>790 degree C). The kinetics of product formation was studied using XRD analysis and magnetic susceptibility. The kinetics were shown to follow the nucleation and growth mechanism. Bi2223 formed after only 30 min at a few degrees below the melting point, and after 37 h Bi2223 products exhibited excellent phase composition and magnetic susceptibility characteristics

  17. Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials

    Directory of Open Access Journals (Sweden)

    Angelika-Ioanna Gialleli

    2017-01-01

    Full Text Available Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C. The positive eff ect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose signifi cantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the eff ect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confi rmed by the analysis of the fi nal products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profi le and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

  18. Effect of Glycerol, as Cryoprotectant in the Encapsulation and Freeze Drying of Microspheres Containing Probiotic Cells

    Directory of Open Access Journals (Sweden)

    Oana Lelia Pop

    2015-05-01

    Full Text Available It is reported that probiotics provide several health benefits as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. Ensuring adequate dosages of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants. In this study, probiotic cells (Bifidobacterium lactis 300B were entrapped in alginate/pullulan microspheres. In the encapsulation formula glycerol was used as cryoprotectant in the freeze drying process for long time storage. It was observed that the survival of Bifidobacterium lactis 300B when encapsulated without cryoprotectant was higher than the formula with glycerol in the fresh obtained microspheres. The addition of glycerol was in order to reduce the deep freezing and freeze drying damages. In the chosen formulations, glycerol did not proved protection for the entrapped probiotic cells in the freeze drying process, for which the use of glycerol as cryoprotectant for alginate/pullulan Bifidobacterium lactis 300B entrapment is not recommended.

  19. Fuzzy Logic-based expert system for evaluating cake quality of freeze-dried formulations.

    Science.gov (United States)

    Trnka, Hjalte; Wu, Jian X; Van De Weert, Marco; Grohganz, Holger; Rantanen, Jukka

    2013-12-01

    Freeze-drying of peptide and protein-based pharmaceuticals is an increasingly important field of research. The diverse nature of these compounds, limited understanding of excipient functionality, and difficult-to-analyze quality attributes together with the increasing importance of the biosimilarity concept complicate the development phase of safe and cost-effective drug products. To streamline the development phase and to make high-throughput formulation screening possible, efficient solutions for analyzing critical quality attributes such as cake quality with minimal material consumption are needed. The aim of this study was to develop a fuzzy logic system based on image analysis (IA) for analyzing cake quality. Freeze-dried samples with different visual quality attributes were prepared in well plates. Imaging solutions together with image analytical routines were developed for extracting critical visual features such as the degree of cake collapse, glassiness, and color uniformity. On the basis of the IA outputs, a fuzzy logic system for analysis of these freeze-dried cakes was constructed. After this development phase, the system was tested with a new screening well plate. The developed fuzzy logic-based system was found to give comparable quality scores with visual evaluation, making high-throughput classification of cake quality possible. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials.

    Science.gov (United States)

    Gialleli, Angelika-Ioanna; Ganatsios, Vassilios; Terpou, Antonia; Kanellaki, Maria; Bekatorou, Argyro; Koutinas, Athanasios A; Dimitrellou, Dimitra

    2017-09-01

    Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C). The positive effect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose significantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the effect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confirmed by the analysis of the final products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profile and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

  1. Drying of α-amylase by spray drying and freeze-drying - a comparative study

    Directory of Open Access Journals (Sweden)

    S. S. de Jesus

    2014-09-01

    Full Text Available This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

  2. Application of plackett-burman design in screening freeze drying cryoprotectants for Lactobacillus bulgaricus

    Directory of Open Access Journals (Sweden)

    Guowei SHU

    2015-08-01

    Full Text Available Lactobacillus bulgaricus is the bacteria commonly used in probiotic dairy product, including yogurt and cheese. The bacteria may be stored for long periods of time if it is freeze-dried. The cryoprotectant mixture for L. bulgaricus was optimized during the process of freeze-drying using a Plackett-Burman design and the steepest ascent test. In our initial tests, the cell survival rate and the number of viable cells were associated with the type of cyroprotectant used. Therefore, our optimization protocol focused on increasing survival rate. Substances that previously had a protective effect during freeze-drying were investigated, for example: sucrose, lactose, skim milk powder, sodium bicarbonate, sodium glutamate, magnesium sulfate, sodium ascorbate, yeast extract, vitamin B2, and phosphate buffer. We determined that the optimum cryoprotectant composition for L. bulgaricus consists of 28.0 g/100 mL skim milk powder, 24.0 g/100 mL lactose and 4.8 g/100 mL sodium ascorbate. The optimized cryoprotectant provides a 63.25% cell survival rate.

  3. Determination of free amino acids and 18 elements in freeze-dried strawberry and blueberry fruit using an Amino Acid Analyzer and ICP-MS with micro-wave digestion.

    Science.gov (United States)

    Zhang, Hua; Wang, Zhen-Yu; Yang, Xin; Zhao, Hai-Tian; Zhang, Ying-Chun; Dong, Ai-Jun; Jing, Jing; Wang, Jing

    2014-03-15

    The objective of this study was to investigate the level of 18 trace elements of two freeze-dried samples from the Blueberry (Vaccinium corymbosum) and the Strawberry (Fragaria × Ananassa). The total free amino acid composition in the blueberry and strawberry was determined by an Amino Acid Analyzer. Eleven free amino acids were found in both berries. The trace elements in each dried fruit sample were determined by ICP-MS with microwave digestion. The linearity range of the standard curves was 0-1250.0 μg L(-1) (Mg, P, K, Ca),while in all cases, except for B, Na, Al, Cr, Mn, Fe, Ni, Cu, Zn, Se, Cd, Pb, Ge and As, which was 125.0 μg mL(-1), all related coefficients were above 0.9999; recovery was in the range of 79.0-106.8%. Minor concentrations of nutritional elements were found in each freeze-dried berry. In sum, the toxic trace element analysis found the content of toxic trace elements in each freeze-dried berry sample was safe for human consumption and that the overall quality of the blueberry surpassed that of the strawberry. The results certify that the two freeze-dried berries have potential for human consumption in value-added products and have a certain theoretical and practical significance. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  4. The influence of freezing rates on bovine pericardium tissue Freeze-drying

    Directory of Open Access Journals (Sweden)

    Camila Figueiredo Borgognoni

    2009-12-01

    Full Text Available The bovine pericardium has been used as biomaterial in developing bioprostheses. Freeze-drying is a drying process that could be used for heart valve's preservation. The maintenance of the characteristics of the biomaterial is important for a good heart valve performance. This paper describes the initial step in the development of a bovine pericardium tissue freeze-drying to be used in heart valves. Freeze-drying involves three steps: freezing, primary drying and secondary drying. The freezing step influences the ice crystal size and, consequently, the primary and secondary drying stages. The aim of this work was to investigate the influence of freezing rates on the bovine pericardium tissue freeze-drying parameters. The glass transition temperature and the structural behaviour of the lyophilized tissues were determined as also primary and secondary drying time. The slow freezing with thermal treatment presented better results than the other freeze-drying protocols.O pericárdio bovino é um material utilizado na fabricação de biopróteses. A liofilização é um método de secagem que vem sendo estudado para a conservação de válvulas cardíacas. A preservação das características do biomaterial é de fundamental importância no bom funcionamento das válvulas. Este artigo é a primeira etapa do desenvolvimento do ciclo de liofilização do pericárdio bovino. Liofilização é o processo de secagem no qual a água é removida do material congelado por sublimação e desorção da água incongelável, sob pressão reduzida. O congelamento influencia o tamanho do cristal de gelo e, consequentemente, a secagem primária e secundária. O objetivo deste estudo foi verificar a influência das taxas de congelamento nos parâmetros de liofilização do pericárdio bovino. Determinou-se a temperatura de transição vítrea e o comportamento estrutural do pericárdio bovino liofilizado. Determinou-se o tempo da secagem primária e secundária. O

  5. Allogenic bone rods with freeze drying and gamma rays irradiation for treatment of fracture

    International Nuclear Information System (INIS)

    Zhou Zhenbin

    1999-01-01

    Opened reduction and internal fixation are the usual treatment of fracture, but both methods need a second operation for removal implants. The benefits of the bone rods are that they can avoid the removement of internal fixation and will be absorbed spontaneously. The bone rods are made of allogeneic compact bones with freeze-drying and gamma rays irradiation supplied by Shanxi Provincial Tissue Bank. The purpose of this study is to evaluate allograft reaction, the stability of the internal fixation, osteoinduction in the treatment of fracture using allogeneic bone rods with freeze drying and gamma rays irradiation. From May 1997 to May 1998, fourteen cases (male 12, female 2) of treatment were reviewed. The mean age was 37.3 (21-5 1). There were 3 medial malleolus fractures, 7 tibia and fibula fractures, 1 ulna and radius fracture, 1 lateral condyle of humerus fracture. The clinical results were satisfactory. Because the strength of the bone rods are weaker than that of screws, the bone rods are only indicated in the fixation of cancellous bones fracture and unloaded bone fracture. It can be used as a supplementary fixation of loaded bone. It is not indicated for fixation of comminuted fracture. More than two bone rods may be used in the fixation of fracture in order to get stability of the fracture and decrease stress between rods which will prevent the break of the bone rods. Allogeneic bone rods with freeze-drying and gamma rays irradiation can be used as implants of non-immunogenicity. There are no allograft reactions in all cases (including fever, leukocytosis, exudation or swelling in the wound). Although plenty of experimental studies have showed that freeze drying with gamma rays irradiation (below 50 KGy) would not destroy BMP of bone allograft, but there is no osteoinduction in our cases. The healing of a fracture and bridging external callus are similar as other operations. This new technique may have the following advantages compare with the screws: 1

  6. Changes in non-volatile taste components of button mushroom (Agaricus bisporus) during different stages of freeze drying and freeze drying combined with microwave vacuum drying.

    Science.gov (United States)

    Pei, Fei; Shi, Ying; Gao, Xingyang; Wu, Fangning; Mariga, Alfred Mugambi; Yang, Wenjian; Zhao, Liyan; An, Xinxin; Xin, Zhihong; Yang, Fangmei; Hu, Qiuhui

    2014-12-15

    Button mushroom slices were dehydrated using freeze drying (FD) or FD combined with microwave vacuum drying (FMVD), and the non-volatile component profiles were studied. The results showed that the level of non-volatile components in button mushroom firstly increased during sublimation of FD/FMVD process and then fell during desorption in FD process and MVD in FMVD process. Compared to FD products, the contents of soluble sugars and polyols in FMVD products were relatively low, whereas the contents of total free amino acids were significantly higher, close to the level of fresh mushroom. However, there was no significant difference in the contents of 5'-nucleotides and organic acids between FD and FMVD products. The equivalent umami concentration (EUC) values for FD and FMVD products did not differ from fresh, indicating that both drying methods could effectively preserve MSG (monosodium glutamate)-like components in button mushroom. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying.

    Science.gov (United States)

    Li, Chun; Sun, Jinwei; Qi, Xiaoxi; Liu, Libo

    2015-01-01

    The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level.

  8. Uncertainty analysis as essential step in the establishment of the dynamic Design Space of primary drying during freeze-drying

    DEFF Research Database (Denmark)

    Mortier, Severine Therese F. C.; Van Bockstal, Pieter-Jan; Corver, Jos

    2016-01-01

    Large molecules, such as biopharmaceuticals, are considered the key driver of growth for the pharmaceutical industry. Freeze-drying is the preferred way to stabilise these products when needed. However, it is an expensive, inefficient, time- and energy-consuming process. During freeze-drying, the......Large molecules, such as biopharmaceuticals, are considered the key driver of growth for the pharmaceutical industry. Freeze-drying is the preferred way to stabilise these products when needed. However, it is an expensive, inefficient, time- and energy-consuming process. During freeze...... for pharmaceutical freeze-drying. Traditionally, the chamber pressure and shelf temperature are kept constant during primary drying, leading to less optimal process conditions. In this paper it is demonstrated how a mechanistic model of the primary drying step gives the opportunity to determine the optimal dynamic...

  9. A comparative evaluation of freeze dried bone allograft and decalcified freeze dried bone allograft in the treatment of intrabony defects: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Rajat Gothi

    2015-01-01

    Full Text Available Background: Ideal graft material for regenerative procedures is autogenous bone graft but the major disadvantage with this graft is the need for a secondary surgical site to procure donor material and the frequent lack of intraoral donor site to obtain sufficient quantities of autogenous bone for multiple or deep osseous defects. Hence, to overcome these disadvantages, bone allografts were developed as an alternative source of graft material. Materials and Methods: In 10 patients with chronic periodontitis, 20 bilateral infrabony defects were treated with freeze dried bone allograft (FDBA-Group A and decalcified freeze dried bone allograft (DFDBA-Group B. Clinical and radiographic parameters were assessed preoperatively and at 3 months and 6 months postoperatively. Data thus obtained was subjected to statistical analysis. Results: Significant improvement in the reduction in probing depth and relative attachment level (RAL from the baseline to 3 months to baseline to 6 months in group A and group B, which was statistically significant but no statistically significant reduction was seen between 3 months and 6 months. On inter-group comparison, no significant differences were observed at all-time points. In adjunct to the probing depth and RAL, the radiographic area of the defect showed a similar trend in intra-group comparison and no significant difference was seen on inter-group comparison at all-time points. Conclusions: Within the limitations of the current study, it can be concluded that DFDBA did not show any improvement in the clinical and radiographic parameters in the treatment of the intrabony defects as compared to FDBA.

  10. Survival of freeze-dried microcapsules of α-galactosidase producing probiotics in a soy bar matrix.

    Science.gov (United States)

    Chen, Mo; Mustapha, Azlin

    2012-05-01

    Soy oligosaccharides, mainly α-galactosides, are prevalently present in soy protein products, and can result in unfavorable digestive effects when consumed. The aim of this research was to investigate the efficiency of α-galactoside reduction by probiotic bacterial hydrolysis and if such bacteria could be maintained in a high number in a soy protein product in a microencapsulated and freeze-dried form. The probiotic bacterium, Lactobacillus acidophilus LA-2, when induced by raffinose, exhibited a high level of α-galactosidase activity at 5.0 U/mg. To preserve probiotics with high viability, cells were microencapsulated and freeze-dried. Optimization of microencapsulation presented that a combination of κ-carrageenan and inulin at a proportion of 1.9:0.1 (w:w) as capsule wall materials, significantly retained the viability of the probiotics through freeze-drying (P ≤ 0.05). Scanning electron microscopic images confirmed that the morphology of the microcapsules was well preserved after freeze-drying. Upon incorporation into soy protein bars, the freeze-dried microcapsules of L. acidophilus LA-2 remained in high numbers throughout 14 weeks of storage at 4 °C. Results of this work with the support of other studies on microencapsulation benefits indicate a promising use of freeze-dried α-galactosidase positive microencapsulated probiotics in a soy food. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Freeze drying reduces the extractability of organochlorine pesticides in fish muscle tissue by microwave-assisted method

    International Nuclear Information System (INIS)

    Zhang, Yanyan; Lin, Nan; Su, Shu; Shen, Guofeng; Chen, Yuanchen; Yang, Chunli; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Han; Wang, Xilong; Liu, Wenxin; Tao, Shu

    2014-01-01

    Samples of animal origin are usually dried before solvent extraction for analysis of organic contaminants. The freeze drying technique is preferred for hydrophobic organic compounds in practice. In this study, it was shown that the concentration of organochlorine pesticides (OCPs) extracted from fish muscle tissue significantly decreased after the samples were freeze dried. And the reason for this reduced extractability seemed to be the resistance of OCPs associated with freeze-dried muscle protein to solvent extraction. The extractability can be recovered by adding water prior to extraction. It suggests that the dietary exposure risk of OCPs from fish might be underestimated if freeze-dried samples are used. - Highlights: • Freeze drying significantly reduces extractability of OCPs in fish muscle sample. • It is the protein that causes the reduction in extractability of OCPs. • The extractability can be recovered by adding water before extraction. - Freeze drying significantly decreases the concentrations of OCPs extracted from fish muscle samples by microwave-assisted method

  12. Freeze-dried, mucoadhesive system for vaginal delivery of the HIV microbicide, dapivirine: optimisation by an artificial neural network.

    Science.gov (United States)

    Woolfson, A David; Umrethia, Manish L; Kett, Victoria L; Malcolm, R Karl

    2010-03-30

    Dapivirine mucoadhesive gels and freeze-dried tablets were prepared using a 3x3x2 factorial design. An artificial neural network (ANN) with multi-layer perception was used to investigate the effect of hydroxypropyl-methylcellulose (HPMC): polyvinylpyrrolidone (PVP) ratio (X1), mucoadhesive concentration (X2) and delivery system (gel or freeze-dried mucoadhesive tablet, X3) on response variables; cumulative release of dapivirine at 24h (Q(24)), mucoadhesive force (F(max)) and zero-rate viscosity. Optimisation was performed by minimising the error between the experimental and predicted values of responses by ANN. The method was validated using check point analysis by preparing six formulations of gels and their corresponding freeze-dried tablets randomly selected from within the design space of contour plots. Experimental and predicted values of response variables were not significantly different (p>0.05, two-sided paired t-test). For gels, Q(24) values were higher than their corresponding freeze-dried tablets. F(max) values for freeze-dried tablets were significantly different (2-4 times greater, p>0.05, two-sided paired t-test) compared to equivalent gels. Freeze-dried tablets having lower values for X1 and higher values for X2 components offered the best compromise between effective dapivirine release, mucoadhesion and viscosity such that increased vaginal residence time was likely to be achieved. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  13. Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors

    International Nuclear Information System (INIS)

    Gómez, A.; Villanueva, R.; Vie, D.; Murcia-Mascaros, S.; Martínez, E.; Beltrán, A.; Sapiña, F.; Vicent, M.; Sánchez, E.

    2013-01-01

    Nanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10–15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures. - Graphical abstract: Zr 1−x A x O 2−x/2 (A=Y, Sc; 0≤x≤0.12) solid solutions have been prepared as nanostructured powders by thermal decomposition of precursors obtained by freeze-drying, and this synthetic procedure has been scaled up to the 100 g scale. Highlights: ► Zr 1−x A x O 2−x/2 (A=Y, Sc; 0≤x≤0.12) solid solutions have been prepared as nanostructured powders. ► The synthetic method involves the thermal decomposition of precursors obtained by freeze-drying. ► The temperature of the thermal treatment controls particle sizes. ► The preparation procedure has been scaled up to the 100 g scale. ► This method is appropriate for the large-scale industrial preparation of multimetallic systems.

  14. Freeze dried blood and development of an artificial diet for blood feeding arthropods

    International Nuclear Information System (INIS)

    DeLoach, J.R.; Spates, G.E.; Kapatsa, G.M.; Sheffield, C.L.; Kabayo, J.P.

    1990-01-01

    The goals of the research were to determine the biochemical differences between freeze dried bovine and porcine blood relative to their nutritional value to Glossina palpalis palpalis and Stomoxys calcitrans and to develop an artificial diet for mass rearing these flies. Freeze dried bovine and porcine blood were found to differ in their amino acid content; total dietary lipids did not significantly differ, but some notable exceptions were found in fatty acid content. Both sonication and addition of foetal bovine serum to freeze dried bovine blood improved its nutritional value for G. p. palpalis. A two component, semi-defined artificial diet was developed for G. p. palpalis and S. calcitrans. The College Station diet consisted of lipid contaminated bovine haemoglobin (BHb) and bovine serum albumin (BSA). To conduct dietary deletion tests, a process was developed for preparing large quantities of ultrapure lipid free bovine haemoglobin. S. calcitrans fed on lipid free BHb plus BSA had zero fecundity. Lipids were re-added to the protein diet in three forms: (1) lipid contaminated BHb, (2) pure erythrocyte ghosts, and (3) pure lipids. It was found that membrane lipid from the erythrocyte is required by S. calcitrans. A defined artificial diet consisting of lipid free BHb, BSA, sphingomyelin, phosphatidyl ethanolamine, phosphatidyl serine and cholesterol gave normal adult survival, as well as near normal fecundity and percentage egg hatch for S. calcitrans. Knowing the identity of the lipids, it is now possible to prepare dietary formulations to alleviate dependency on the blood proteins BHb and BSA. (author). 34 refs, 1 fig., 15 tabs

  15. A freeze-dried graphene counter electrode enhances the performance of dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Kai-Hsiang; Wang, Hong-Wen, E-mail: hongwen@cycu.edu.tw

    2014-01-01

    A flexible graphene/polyimide (PI) counter electrode without a fluorine-doped tin oxide (FTO) layer has been fabricated for dye-sensitized solar cell (DSSCs) applications. The flexible counter electrode consists of polyimide double-sided tape as a substrate beneath a graphene film acting as the conductive and catalytic layer. Chemically reduced graphene oxide (rGO) on the PI electrode (rGO-PI) shows comparable catalytic activity to that of the reference sputtered platinum/FTO counter electrodes (Sputter-Pt/FTO). A DSSC with a freeze-dried rGO-PI (FD-rGO-PI) counter electrode shows an overall conversion efficiency (η) of 5.45%, while that of the conventional Sputter-Pt/FTO electrode is 5.52%. The DSSC with a thermally dried rGO-PI (Gel-rGO-PI) counter electrode (not freeze-dried) exhibits a smooth morphology and much poorer performance (η = 1.61%). Field emission scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry measurements demonstrate that the FD-rGO-PI electrode possesses a porous structure, numerous edges, minimum charge-transfer resistance and a higher electrocatalytic activity toward the I{sub 3}{sup −}/I{sup −} redox couple than that of the Gel-rGO-PI electrode. The high electrocatalytic activity, facile preparation procedure, absence of FTO, and material flexibility render the FD-rGO-PI electrode an ideal alternative to conventional DSSC counter electrodes. - Highlights: • Highly rough and conductive graphene-based counter electrode is synthesized. • The characteristics of graphene surface by freeze drying are different. • The graphene counter electrode exhibits comparable performance to that of sputtered Pt one.

  16. Conservation of waterlogged wood by freeze-drying and optional resin impregnation

    International Nuclear Information System (INIS)

    Schaudy, R.

    1987-09-01

    As a contribution to the 'International Comparative Study on Waterlogged Wood' (Grattan-Schweingruber-Project) of the ICOM Working Group on Waterlogged Organic Materials seven archaeological wood samples from sites in Canada, England, the Netherlands, Japan, Norway and Western Australia have been treated. The conservation process consisted of freeze-drying following a polyethylene glycol (PEG 400) treatment and - for fragile objects - of a resin impregnation using a radiation-curable impregnant and gamma radiation for curing. The results are discussed, however without paying regard to the other contributions to this international study. 20 refs., 3 tabs., 30 figs. (Author)

  17. Electrolysis of polluting wastes: I - Wastewater from a seasoning freeze-drying industry

    OpenAIRE

    Angelis, Dejanira F. de; Corso, Carlos R.; Bidoia, Ederio D.; Moraes, Peterson B.; Domingos, Roberto N.; Rocha-Filho, Romeu C.

    1998-01-01

    Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD) and chemical (COD) oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD) showed that the biodegradability of the wastewater was s...

  18. Freeze drying vs microwave drying–methods for synthesis of sinteractive thoria powders

    Energy Technology Data Exchange (ETDEWEB)

    Annie, D.; Chandramouli, V. [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India); Anthonysamy, S., E-mail: sas@igcar.gov.in [Materials Chemistry Division, Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India); Ghosh, Chanchal; Divakar, R. [Materials Synthesis and Structural Characterization Division, Materials and Metallurgy Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, 602103 (India)

    2017-02-15

    Thoria powders were synthesized by oxalate precipitation from an aqueous solution of the nitrate. The filtered precipitates were freeze dried or microwave dried before being calcined at 1073 K. The thoria powders obtained were characterized for crystallite size, specific surface area, bulk density, particle size distribution and residual carbon. Microstructure of the product was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Sinterability of the synthesized powders was studied by measuring the density of the sintered compacts. Powders that can be consolidated and sintered to densities ∼96% theoretical density (TD) at 1773 K were obtained.

  19. Microbial analysis and survey test of gamma-irradiated freeze-dried fruits for patient's food

    International Nuclear Information System (INIS)

    Park, Jae-Nam; Sung, Nak-Yun; Byun, Eui-Hong; Byun, Eui-Baek; Song, Beom-Seok; Kim, Jae-Hun; Lee, Kyung-A; Son, Eun-Joo; Lyu, Eun-Soon

    2015-01-01

    This study examined the microbiological and organoleptic qualities of gamma-irradiated freeze-dried apples, pears, strawberries, pineapples, and grapes, and evaluated the organoleptic acceptability of the sterilized freeze-dried fruits for hospitalized patients. The freeze-dried fruits were gamma-irradiated at 0, 1, 2, 3, 4, 5, 10, 12, and 15 kGy, and their quality was evaluated. Microorganisms were not detected in apples after 1 kGy, in strawberries and pears after 4 kGy, in pineapples after 5 kGy, and in grapes after 12 kGy of gamma irradiation. The overall acceptance score, of the irradiated freeze-dried fruits on a 7-point scale at the sterilization doses was 5.5, 4.2, 4.0, 4.1, and 5.1 points for apples, strawberries, pears, pineapples, and grapes, respectively. The sensory survey of the hospitalized cancer patients (N=102) resulted in scores of 3.8, 3.7, 3.9, 3.9, and 3.7 on a 5-point scale for the gamma-irradiated freeze-dried apples, strawberries, pears, pineapples, and grapes, respectively. The results suggest that freeze-dried fruits can be sterilized with a dose of 5 kGy, except for grapes, which require a dose of 12 kGy, and that the organoleptic quality of the fruits is acceptable to immuno-compromised patients. However, to clarify the microbiological quality and safety of freeze-dried fruits should be verified by plating for both aerobic and anaerobic microorganisms. - Highlights: • Dried fruits can be sterilized with a dose of 12 kGy. • Sensory survey of the hospitalized cancer patients (N=102). • Sensory quality of dried fruits is acceptable to cancer patients

  20. Experimental determination of the key heat transfer mechanisms in pharmaceutical freeze-drying.

    Science.gov (United States)

    Ganguly, Arnab; Nail, Steven L; Alexeenko, Alina

    2013-05-01

    The study is aimed at quantifying the relative contribution of key heat transfer modes in lyophilization. Measurements of vial heat transfer rates in a laboratory-scale freeze-dryer were performed using pure water, which was partially sublimed under various conditions. The separation distance between the shelf and the vial was systematically varied, and sublimation rates were determined gravimetrically. The heat transfer rates were observed to be independent of separation distance between the vial and the shelf and linearly dependent on pressure in the free molecular flow limit, realized at low pressures (120 mTorr), heat transfer rates were independent of pressure and inversely proportional to separation distance. Previous heat transfer studies in conventional freeze-drying cycles have attributed a dominant portion of the total heat transfer to radiation, the rest to conduction, whereas convection has been found to be insignificant. Although the measurements reported here confirm the significance of the radiative and gas conduction components, the convective component has been found to be comparable to the gas conduction contribution at pressures greater than 100 mTorr. The current investigation supports the conclusion that the convective component of the heat transfer cannot be ignored in typical laboratory-scale freeze-drying conditions. Copyright © 2013 Wiley Periodicals, Inc.

  1. Effect of Controlled Ice Nucleation on Stability of Lactate Dehydrogenase During Freeze-Drying.

    Science.gov (United States)

    Fang, Rui; Tanaka, Kazunari; Mudhivarthi, Vamsi; Bogner, Robin H; Pikal, Michael J

    2018-03-01

    Several controlled ice nucleation techniques have been developed to increase the efficiency of the freeze-drying process as well as to improve the quality of pharmaceutical products. Owing to the reduction in ice surface area, these techniques have the potential to reduce the degradation of proteins labile during freezing. The objective of this study was to evaluate the effect of ice nucleation temperature on the in-process stability of lactate dehydrogenase (LDH). LDH in potassium phosphate buffer was nucleated at -4°C, -8°C, and -12°C using ControLyo™ or allowed to nucleate spontaneously. Both the enzymatic activity and tetramer recovery after freeze-thawing linearly correlated with product ice nucleation temperature (n = 24). Controlled nucleation also significantly improved batch homogeneity as reflected by reduced inter-vial variation in activity and tetramer recovery. With the correlation established in the laboratory, the degradation of protein in manufacturing arising from ice nucleation temperature differences can be quantitatively predicted. The results show that controlled nucleation reduced the degradation of LDH during the freezing process, but this does not necessarily translate to vastly superior stability during the entire freeze-drying process. The capability of improving batch homogeneity provides potential advantages in scaling-up from lab to manufacturing scale. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  2. Development of a Freeze-Dried Fungal Wettable Powder Preparation Able to Biodegrade Chlorpyrifos on Vegetables

    Science.gov (United States)

    Chen, Shaohua; Xiao, Ying; Hu, Meiying; Zhong, Guohua

    2014-01-01

    Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711), a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM). The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues. PMID:25061758

  3. Production of grape juice powder obtained by freeze-drying after concentration by reverse osmosis

    Directory of Open Access Journals (Sweden)

    Poliana Deyse Gurak

    2013-12-01

    Full Text Available This study aimed to evaluate the freeze-drying process for obtaining grape juice powder by reverse osmosis using 50% grape juice pre-concentrated (28.5 °Brix and 50% hydrocolloids (37.5% maltodextrin and 12.5% arabic gum. The morphology of the glassy food showed the absence of crystalline structure, which was the amorphous wall that protected the contents of the powder. The samples were stored in clear and dark containers at room temperature, evaluated for their physical (X-ray diffraction for 65 days and chemical (polyphenol content stability for 120 days. During the storage time in plastic vessels, samples remained physically stable (amorphous and the phenolic concentration was constant, indicating the potentiality of this technique to obtain a stable product with a high concentration of phenolic compounds. Therefore, the freeze-drying process promoted the encapsulation of concentrated grape juice increasing its stability and shelf life, as well as proving to be an applicable process to food industry

  4. Microencapsulation of Natural Anthocyanin from Purple Rosella Calyces by Freeze Drying

    Science.gov (United States)

    Nafiunisa, A.; Aryanti, N.; Wardhani, D. H.; Kumoro, A. C.

    2017-11-01

    Anthocyanin extract in powder form will improve its use since the powder is easier to store and more applicable. Microencapsulation method is introduced as an efficient way for protecting pigment such as anthocyanin. This research was aimed to characterise anthocyanin encapsulated products prepared from purple Roselle calyces by freeze drying. The liquid anthocyanin extracts from ultrasound-assisted extraction were freeze-dried with and without the addition of 10% w/w maltodextrins as a carrier and coating agents. The quality attributes of the powders were characterised by their colour intensity, water content, and solubility. Analysis of encapsulated material was performed for the powder added by maltodextrin. The stability of the microencapsulated pigment in solution form was determined for 11 days. Total anthocyanin content was observed through pH differential method. The results of the colour intensity analysis confirm that the product with maltodextrin addition has more intense colour with L* value of 29.69 a* value of 54.29 and b* value of 8.39. The result with the addition of maltodextrin has less moisture content and more soluble in water. It is verified that better results were obtained for powder with maltodextrin addition. Anthocyanin in the powder form with maltodextrin addition exhibits higher stability even after 11 days. In conclusion, the microencapsulation of anthocyanin with maltodextrin as a carrier and coating agent presented a potential method to produce anthocyanin powder from purple Roselle.

  5. Evaluation of Heat Flux Measurement as a New Process Analytical Technology Monitoring Tool in Freeze Drying.

    Science.gov (United States)

    Vollrath, Ilona; Pauli, Victoria; Friess, Wolfgang; Freitag, Angelika; Hawe, Andrea; Winter, Gerhard

    2017-05-01

    This study investigates the suitability of heat flux measurement as a new technique for monitoring product temperature and critical end points during freeze drying. The heat flux sensor is tightly mounted on the shelf and measures non-invasively (no contact with the product) the heat transferred from shelf to vial. Heat flux data were compared to comparative pressure measurement, thermocouple readings, and Karl Fischer titration as current state of the art monitoring techniques. The whole freeze drying process including freezing (both by ramp freezing and controlled nucleation) and primary and secondary drying was considered. We found that direct measurement of the transferred heat enables more insights into thermodynamics of the freezing process. Furthermore, a vial heat transfer coefficient can be calculated from heat flux data, which ultimately provides a non-invasive method to monitor product temperature throughout primary drying. The end point of primary drying determined by heat flux measurements was in accordance with the one defined by thermocouples. During secondary drying, heat flux measurements could not indicate the progress of drying as monitoring the residual moisture content. In conclusion, heat flux measurements are a promising new non-invasive tool for lyophilization process monitoring and development using energy transfer as a control parameter. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  6. Effects of ultrasonic pretreatments on quality, energy consumption and sterilization of barley grass in freeze drying.

    Science.gov (United States)

    Cao, Xiaohuang; Zhang, Min; Mujumdar, Arun S; Zhong, Qifeng; Wang, Zhushang

    2018-01-01

    Barley grass is a plant resource for rehabilitation therapy. Its processing requires retaining nutrition well for rehabilitation cure of consumers. To meet the aim as well as low energy consumption and microbiological safety of products, ultrasonic treatments (UT) were applied to bathing materials at different power levels (10, 30, 45, 60W/L) for 10mins. After treatments, the bathed barley grass (100g) was freeze-dried under vacuum -0.09MPa with fixed power of 2W/g. Parameters of color, microbial colony, energy consumption, glass transition temperature, moisture content, water activity, taste substances, contents of flavonoid and chlorophyll were determined after drying. In contrast with no treatment case, UT (45W/L) decreased drying time by 14% and decreased energy consumption by 19%; UT (60W/L) decreased total microbial colonies by 33%. Also, UT (30W/L) yielded contents of flavonoid (9.2/kg) and chlorophyll (10.5g/kg) of dried sample; UT power (10W/L) yielded the highest L ∗ (51.5) and the lowest a ∗ (-9.3) value. Simultaneously, UT leads to a higher glass transition temperature (Tg), lower water activity and produces less sourness and bitterness of dried products. Ultra-sonication is an alternative to improve quality, flavor and energy consumption of barley grass in freeze drying. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Increasing the aperture of x-ray mosaic lenses by freeze drying

    International Nuclear Information System (INIS)

    Koch, F; Marschall, F; Meiser, J; Márkus, O; Faisal, A; Schröter, T; Meyer, P; Kunka, D; Last, A; Mohr, J

    2015-01-01

    Point focus x-ray mosaic lenses are limited in aperture by the aspect ratio that can be reached in the micro fabrication process. In lithography based micro fabrication processes, which are used to fabricate the lens pillar structures, the achievable aspect ratio is restricted by structure collapse due to capillary forces which occur during drying after development. Capillary forces can be avoided by freeze drying, hence avoiding the direct phase change from liquid to gas. Substituting conventional drying by freeze drying using cyclohexane at a temperature of  −10 °C, we could increase the achievable aspect ratio for the triangular pillar structures with edge length of 10 to 45 µm of the x-ray mosaic lenses by up to a factor of 2.2 with no further changes in process, material or structural geometry. A maximum aspect ratio of 30 was achieved for pillars with 10 µm edge length. The process can readily be employed to other structures or lithography techniques. (paper)

  8. Improvement of fish freshness determination method by the application of amorphous freeze-dried enzymes.

    Science.gov (United States)

    Srirangsan, Paveena; Hamada-Sato, Naoko; Kawai, Kiyoshi; Watanabe, Manabu; Suzuki, Toru

    2010-12-08

    Alkaline phosphatase (ALP), nucleoside phosphorylase (NP), and xanthine oxidase (XOD) were used in a colorimetric method for evaluation of fish freshness based on the Ki value. Two enzyme mixtures, NP-XOD and ALP-NP-XOD, were prepared with a color developing agent, and stabilities of the enzymes were improved by freeze-drying with glass-forming additives, i.e., sucrose and sucrose-gelatin. As a result, a linear relationship was obtained between the Ki values determined by the developed colorimetric method and a conventional high-performance liquid chromatography with a high correlation coefficient of 0.997. All enzyme samples containing the additive(s) were amorphous, and higher enzymes activities were maintained compared to those freeze-dried without an additive. Sucrose-gelatin/enzyme mixtures showed higher glass transition temperature; consequently, the enzymes were better stabilized than the sucrose/enzyme formulations. Using the sucrose-gelatin/enzyme mixture, Ki values of fish meat could be accurately determined even after 6-month storage of the dried enzymes at 40 °C.

  9. Quantitative analysis of d,1-HMPAO and its freeze-dried kit with HPLC

    International Nuclear Information System (INIS)

    Chen Suzhen

    1993-05-01

    A quantitative analysis method, which uses RP-HPLC (reversed phase-high performance liquid chromatography), has been established to determine the stereoisomeric purity of HMPAO and d,1-HMPAO content for d,l-HMPAO freeze-dried kit. An opitmal mobile phase is selected for obtaining chromatographic parameters that are better than those published in the references. The theoretical tray height is less than 0.06 mm. At the flowrate of 1 ml/min the total separation time is 5.5. The resolution is greater than 5. The detectable limits of meso-HMPAO and d,l-HMPAO are 1 x 10 -8 g and 5 x 10 -7 g respectively. The precision is 5% and the additional recovery is 94% ∼ 107%. This method has many advantages such as accuracy, simplicity, rapidity and stability, and it is suitable for routine inspection. It has been successfully used to determine the HMPAO stereoisomer and d,1-HMPAO of freeze-dried kit produced by China Institute of Atomic Energy and same products imported from Amersham Company of United Kingdom

  10. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  11. Atmospheric Spray Freeze-Drying: Numerical Modeling and Comparison With Experimental Measurements.

    Science.gov (United States)

    Borges Sebastião, Israel; Robinson, Thomas D; Alexeenko, Alina

    2017-01-01

    Atmospheric spray freeze-drying (ASFD) represents a novel approach to dry thermosensitive solutions via sublimation. Tests conducted with a second-generation ASFD equipment, developed for pharmaceutical applications, have focused initially on producing a light, fine, high-grade powder consistently and reliably. To better understand the heat and mass transfer physics and drying dynamics taking place within the ASFD chamber, 3 analytical models describing the key processes are developed and validated. First, by coupling the dynamics and heat transfer of single droplets sprayed into the chamber, the velocity, temperature, and phase change evolutions of these droplets are estimated for actual operational conditions. This model reveals that, under typical operational conditions, the sprayed droplets require less than 100 ms to freeze. Second, because understanding the heat transfer throughout the entire freeze-drying process is so important, a theoretical model is proposed to predict the time evolution of the chamber gas temperature. Finally, a drying model, calibrated with hygrometer measurements, is used to estimate the total time required to achieve a predefined final moisture content. Results from these models are compared with experimental data. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Stabilization of Live Attenuated Influenza Vaccines by Freeze Drying, Spray Drying, and Foam Drying.

    Science.gov (United States)

    Lovalenti, Phillip M; Anderl, Jeff; Yee, Luisa; Nguyen, Van; Ghavami, Behnaz; Ohtake, Satoshi; Saxena, Atul; Voss, Thomas; Truong-Le, Vu

    2016-05-01

    The goal of this research is to develop stable formulations for live attenuated influenza vaccines (LAIV) by employing the drying methods freeze drying, spray drying, and foam drying. Formulated live attenuated Type-A H1N1 and B-strain influenza vaccines with a variety of excipient combinations were dried using one of the three drying methods. Process and storage stability at 4, 25 and 37°C of the LAIV in these formulations was monitored using a TCID50 potency assay. Their immunogenicity was also evaluated in a ferret model. The thermal stability of H1N1 vaccine was significantly enhanced through application of unique formulation combinations and drying processes. Foam dried formulations were as much as an order of magnitude more stable than either spray dried or freeze dried formulations, while exhibiting low process loss and full retention of immunogenicity. Based on long-term stability data, foam dried formulations exhibited a shelf life at 4, 25 and 37°C of >2, 1.5 years and 4.5 months, respectively. Foam dried LAIV Type-B manufactured using the same formulation and process parameters as H1N1 were imparted with a similar level of stability. Foam drying processing methods with appropriate selection of formulation components can produce an order of magnitude improvement in LAIV stability over other drying methods.

  13. Optimization of freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel.

    Science.gov (United States)

    Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd

    2012-01-01

    Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (-2.66, 62.66 mg/mL), Arabic gum (-1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved.

  14. Separation of nitrogen-krypton by the freeze-dried cellulose acetate membrane

    International Nuclear Information System (INIS)

    Tanioka, Akihiko; Ishikawa, Kinzo; Kakuta, Akio; Ozaki, Osamu; Oono, Masanori.

    1977-01-01

    The utility of freeze-dried cellulose acetate membranes, which consist of a thin skin layer supported upon a more porous matrix substructure, was examined for separation of nitrogen-radioactive krypton 85. The high permeable and separative membranes were prepared by fixed freezed-drying of swollen membrane after evaporation of acetone for 4-6 minutes. The permeation rate of nitrogen was 10 -1 -10 -3 (cc/cm 2 .sec.atm). Knudsen flow was predominant, since the permeation rate was inversely proportional to square root of molecular weight of gases. The influence of viscous flow was also observed by slight dependence on the pressure. The mean pore size was calculated by the equation of gas permeation in porous media. There exist fine pores of 30-40A radii in the skin layer. The separation factor (dilution of Kr) was about 0.7 and the separation efficiency was 60%. The collision between different gas molecules (Present-de Bethunes' effect) and the influence of viscous flow depreciates the efficiency. The separation efficiency which was determined by the experiment coincided with the one predicted according to the Present-de Bethunes' equation, supposing that the pore size in skin layer was 10-25A. (auth.)

  15. Freeze-drying technology: A separation technique for liquid nuclear materials

    International Nuclear Information System (INIS)

    Musgrave, J.A.; Efurd, D.W.; Banar, J.C.

    1997-01-01

    Freeze-drying technology (FDT) has been around for several decades as a separation technology. Most commonly, FDT is associated with the processing of food, but the largest industrial-scale use of FDT is in the pharmaceutical industry. Through a Cooperative Research and Development Agreement (CRADA) with BOC Edwards Calumatic, we are demonstrating the feasibility of FDT as a waste minimization and pollution prevention technology. This is a novel and innovative application of FDT. In addition, we plan to demonstrate that the freeze-dried residue is an ideal feed material for ceramic stabilization of radioactive waste and excess fissile material. The objective of this work is to demonstrate the feasibility of FDT for the separation of complex radioactive and nonradioactive materials, including liquids, slurries, and sludges containing a wide variety of constituents in which the separation factors are >10 8 . This is the first application of FDT in which the condensate is of primary importance. Our focus is applying this technology to the elimination of radioactive liquid discharges from facilities at Los Alamos National Laboratory (LANL) and within the U.S. Department of Energy complex; however, successful demonstration will lead to nuclear industry-wide applications

  16. Development of a freeze-dried fungal wettable powder preparation able to biodegrade chlorpyrifos on vegetables.

    Directory of Open Access Journals (Sweden)

    Jie Liu

    Full Text Available Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711, a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM. The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues.

  17. Effects of physical parameters on the heat and mass transfer characteristics in freeze-drying processes of fruits and vegetables

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yuming; Liu, Lijuan; Liang, Li [Shanxi Agricultural Univ. (China). Coll. of Engineering and Technology], E-mail: guoyuming99@sina.com

    2008-07-01

    Studying the effects mechanism of material physical parameters on the heat and mass transfer characteristics, the process parameters and energy consumption during freeze-drying process is of importance in improving the vacuum freeze-drying process with low energy consumption. In this paper, the sliced and mashed carrots of one variety were selected to perform the vacuum freeze-drying experiments. First, the variation laws of surface temperatures and sublimation front temperatures of the two shapes samples during the freeze-drying processes were analyzed, and it was verified that the process of sliced carrots is controlled by mass transfer, while that of the mashed ones is heat-transfer control. Second, the variations of water loss rate, energy consumption and temperature of the two shapes samples under the appropriate heating plate temperature and the different drying chamber pressure were analyzed. In addition, the effects of thermal conductivity and thermal diffusivity on freeze-drying time and process parameters were discussed by utilizing the theory of heat and mass transfer. In conclusion, under the heat transfer condition, the temperature of the heating plate should be as high as possible within the permitted range, and the drying chamber pressure should be set at optimal level. While under the mass transport-limited condition, the pressure level need to be altered in short time. (author)

  18. Cell surface damage and morphological changes in Oenococcus oeni after freeze-drying and incubation in synthetic wine.

    Science.gov (United States)

    Bravo-Ferrada, Bárbara Mercedes; Gonçalves, Sónia; Semorile, Liliana; Santos, Nuno C; Brizuela, Natalia; Elizabeth Tymczyszyn, E; Hollmann, Axel

    2018-04-28

    The aim of the present study was to evaluate the effects of freeze-drying in the presence of trehalose as a cryoprotectant, followed by incubation in synthetic wine, on surface damage, viability and l-malic acid consumption of the oenological strain Oenococcus oeni UNQOe 73.2. After freeze-drying, no significant differences were observed in the number of viable cells (for both acclimated and non-acclimated cultures) respect to the fresh culture. In contrast, loss of viability was observed after wine incubation for 24 h, being acclimated freeze-dried cells the best conditions for this. After the preservation process, small changes in cell morphology were observed by Atomic Force Microscopy (AFM). The Zeta potential and AFM showed that 24 h of wine incubation was enough to induce several cell surface modifications. Plate count data allowed us to establish that surface damage is an important factor for loss of viability, regardless of the acclimation treatment. Although the number of surviving O. oeni cells decreased dramatically after incubation in synthetic wine for 15 days, the consumption of l-malic acid was higher than 70%, with freeze-dried cells showing a better performance than fresh cultures. These results demonstrate that O. oeni freeze-dried cultures could be applied to direct wine inoculation, to conduct malolactic fermentation, maintaining its technological properties and reducing the time and costs of the winemaking process. Copyright © 2018. Published by Elsevier Inc.

  19. Freeze-dried snake antivenoms formulated with sorbitol, sucrose or mannitol: comparison of their stability in an accelerated test.

    Science.gov (United States)

    Herrera, María; Tattini, Virgilio; Pitombo, Ronaldo N M; Gutiérrez, José María; Borgognoni, Camila; Vega-Baudrit, José; Solera, Federico; Cerdas, Maykel; Segura, Alvaro; Villalta, Mauren; Vargas, Mariángela; León, Guillermo

    2014-11-01

    Freeze-drying is used to improve the long term stability of pharmaceutical proteins. Sugars and polyols have been successfully used in the stabilization of proteins. However, their use in the development of freeze-dried antivenoms has not been documented. In this work, whole IgG snake antivenom, purified from equine plasma, was formulated with different concentrations of sorbitol, sucrose or mannitol. The glass transition temperatures of frozen formulations, determined by Differential Scanning Calorimetry (DSC), ranged between -13.5 °C and -41 °C. In order to evaluate the effectiveness of the different stabilizers, the freeze-dried samples were subjected to an accelerated stability test at 40 ± 2 °C and 75 ± 5% relative humidity. After six months of storage at 40 °C, all the formulations presented the same residual humidity, but significant differences were observed in turbidity, reconstitution time and electrophoretic pattern. Moreover, all formulations, except antivenoms freeze-dried with mannitol, exhibited the same potency for the neutralization of lethal effect of Bothrops asper venom. The 5% (w:v) sucrose formulation exhibited the best stability among the samples tested, while mannitol and sorbitol formulations turned brown. These results suggest that sucrose is a better stabilizer than mannitol and sorbitol in the formulation of freeze-dried antivenoms under the studied conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Freeze-dried formulation for direct {sup 99m}Tc-labeling ior-egf/r3 MAb: additives, biodistribution, and stability

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Alejo A. Morales; Nunez-Gandolff, Gilda; Perez, Niuvis Perez; Veliz, Belkis Chico; Caballero-Torres, Idania; Duconge, Jorge; Fernandez, Eduardo; Crespo, Francisco Zayas; Veloso, Ana; Iznaga-Escobar, Normando E-mail: normando@ict.sld.cu

    1999-08-01

    Monoclonal antibodies (MAbs) have been useful for immunoscintigraphic applications in clinical diagnosis since they were introduced in nuclear medicine practice. The MAb ior egf/r3 developed at the Center of Molecular Immunology (Havana, Cuba) is a murine antibody that recognizes the human epidermal growth factor receptor (EGF-R) and has been used widely in the radioimmunodiagnosis of tumors of epithelial origin. Based on the direct Schwarz method, the present report describes the preparation of a freeze-dried formulation for radiolabeling the MAb ior egf/r3 with {sup 99m}Tc for immunoscintigraphic applications. Radiolabeling efficiency, effects on immunoreactivity, biodistribution, pharmacokinetic, and stability of the formulation are reported. The study demonstrated that the freeze-dried formulation can be labeled with {sup 99m}Tc at high yield. The resulting {sup 99m}Tc-labeled ior egf/r3 MAb can be used to visualize in vivo human tumors of epithelial origin by immunoscintigraphy studies. The kit does not need any other addition or purification at the time of tagging other than the requisite amount of pertechnetate (40-50 mCi). Because the contents of the kit are lyophilized, no special storage or transportation is required.

  1. Freeze-dried formulation for direct 99mTc-labeling ior-egf/r3 MAb: additives, biodistribution, and stability

    International Nuclear Information System (INIS)

    Morales, Alejo A. Morales; Nunez-Gandolff, Gilda; Perez, Niuvis Perez; Veliz, Belkis Chico; Caballero-Torres, Idania; Duconge, Jorge; Fernandez, Eduardo; Crespo, Francisco Zayas; Veloso, Ana; Iznaga-Escobar, Normando

    1999-01-01

    Monoclonal antibodies (MAbs) have been useful for immunoscintigraphic applications in clinical diagnosis since they were introduced in nuclear medicine practice. The MAb ior egf/r3 developed at the Center of Molecular Immunology (Havana, Cuba) is a murine antibody that recognizes the human epidermal growth factor receptor (EGF-R) and has been used widely in the radioimmunodiagnosis of tumors of epithelial origin. Based on the direct Schwarz method, the present report describes the preparation of a freeze-dried formulation for radiolabeling the MAb ior egf/r3 with 99m Tc for immunoscintigraphic applications. Radiolabeling efficiency, effects on immunoreactivity, biodistribution, pharmacokinetic, and stability of the formulation are reported. The study demonstrated that the freeze-dried formulation can be labeled with 99m Tc at high yield. The resulting 99m Tc-labeled ior egf/r3 MAb can be used to visualize in vivo human tumors of epithelial origin by immunoscintigraphy studies. The kit does not need any other addition or purification at the time of tagging other than the requisite amount of pertechnetate (40-50 mCi). Because the contents of the kit are lyophilized, no special storage or transportation is required

  2. Progress of radiosterilization in the Argentine Republic

    International Nuclear Information System (INIS)

    Mariano, E.E.; Mugliaroli, H.A.

    1975-01-01

    The technological and economic advantages of radiation as a means of sterilization have led to a steady expansion of its use. With the significant increase in the radiosterilization of medical products, the health authorities have established standards for the use of radiation for that purpose. These standards will be incorporated in the next edition of the Argentine Pharmacopoeia. In general, Argentine legislation in this area is based on the IAEA's Code of Practice for Radiosterilization of Medical Products. The microbiology services of Argentina's National Atomic Energy Commission (CNEA) determine the number of viable microorganisms in each product and package the product before irradiation. The controls are carried out on random samples. At the same time, the chemistry laboratories carry out quality controls on new products which have received sterilizing doses of gamma radiation. The gas sterilization methods employed most widely in the industrial manufacture of thermolabile products involve the use of ethylene oxide or formaldehyde. The cost of this process is influenced considerably by the fact that Argentina has to import ethylene oxide. The low penetrating power of formaldehyde means that the package containing the product must still be open at the time of sterilization if an adequate safety margin is to be ensured; consequently, one needs sterile installations for the post-irradiation sealing of packages. The capital and operating coats of such installations are high. A comparison has been made of the costs of sterilizing 11000 m 3 of a product with a density of 0.1 g/cm 3 and the following relative values obtained: ethylene oxide, 399.2; formaldehyde, 947.5; gamma radiation, 166.0. Studies of the effects of sterilizing doses on certain pharmaceutical products have demonstrated that the radiosterilization of some drugs is possible. The CNEA has designed an installation for the radiosterilization of medical products; the installation would have a 500000-Ci

  3. Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part 1: Breads Containing Oil as an Ingredient

    Directory of Open Access Journals (Sweden)

    Viren Ranawana

    2016-03-01

    Full Text Available There is increasing emphasis on reformulating processed foods to make them healthier. This study for the first time comprehensively investigated the effects of fortifying bread (containing oil as an ingredient with freeze-dried vegetables on its nutritional and physico-chemical attributes. Breads fortified with carrot, tomato, beetroot or broccoli were assessed for nutrition, antioxidant potential, storage life, shelf stability, textural changes and macronutrient oxidation. Furthermore, using an in vitro model the study for the first time examined the impact of vegetable addition on the oxidative stability of macronutrients during human gastro-intestinal digestion. As expected, adding vegetables improved the nutritional and antioxidant properties of bread. Beetroot and broccoli significantly improved bread storage life. None of the vegetables significantly affected bread textural changes during storage compared to the control. Lipid oxidation in fresh bread was significantly reduced by all four types of vegetables whilst protein oxidation was lowered by beetroot, carrot and broccoli. The vegetables demonstrated varying effects on macronutrient oxidation during gastro-intestinal digestion. Beetroot consistently showed positive effects suggesting its addition to bread could be particularly beneficial.

  4. Electron accelerators for radiosterilization; Akceleratory elektronow dla potrzeb sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The applications of electron accelerators in commercial plants for radiosterilization have been shown. Advantages of such irradiation source have been presented. The types and parameters of accelerators being installed in worldwide irradiation plants for radiosterilization have been listed as well. 2 tabs.

  5. Suitability of microwave drying for mealworms (Tenebrio molitor) as alternative to freeze drying: Impact on nutritional quality and colour.

    Science.gov (United States)

    Lenaerts, S; Van Der Borght, M; Callens, A; Van Campenhout, L

    2018-07-15

    Freeze drying represents the current practice to stabilize mealworms, even though it is an energy demanding technique. Therefore, it was examined in the present study whether microwave drying could be a proper alternative. To this end, the impact of both drying techniques on the proximate composition, vitamin B 12 content, fatty acid profile, oxidation status and colour parameters of mealworms was investigated. Furthermore, the influence of the application of vacuum during microwave drying was studied. The different drying technologies resulted in small differences in the proximate composition, while the vitamin B 12 content was only reduced by microwave drying. The fat fraction of freeze dried mealworms showed a higher oxidation status than the fat of microwave dried mealworms. Application of a vacuum during the microwave drying process did not appear to offer advantages. This research shows that for mealworms microwave drying can be a proper alternative to freeze drying. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. The Production of a Stable Infliximab Powder: The Evaluation of Spray and Freeze-Drying for Production

    Science.gov (United States)

    Kanojia, Gaurav; Have, Rimko ten; Bakker, Arjen; Wagner, Koen; Frijlink, Henderik W.; Kersten, Gideon F. A.; Amorij, Jean-Pierre

    2016-01-01

    In prospect of developing an oral dosage form of Infliximab, for treatment of Crohn’s disease and rheumatoid arthritis, freeze-drying (vial vs Lyoguard trays) and spray-drying were investigated as production method for stable powders. Dextran and inulin were used in combination with sucrose as stabilizing excipients. The drying processes did not affect Infliximab in these formulations, i.e. both the physical integrity and biological activity (TNF binding) were retained. Accelerated stability studies (1 month at 60°C) showed that the TNF binding ability of Infliximab was conserved in the freeze-dried formulations, whereas the liquid counterpart lost all TNF binding. After thermal treatment, the dried formulations showed some chemical modification of the IgG in the dextran-sucrose formulation, probably due to Maillard reaction products. This study indicates that, with the appropriate formulation, both spray-drying and freeze-drying may be useful for (bulk) powder production of Infliximab. PMID:27706175

  7. Porosity and water activity effects on stability of crystalline β-carotene in freeze-dried solids.

    Science.gov (United States)

    Harnkarnsujarit, Nathdanai; Charoenrein, Sanguansri; Roos, Yrjö H

    2012-11-01

    Stability of entrapped crystalline β-carotene as affected by water activity, solids microstructure, and composition of freeze-dried systems was investigated. Aliquots (1000 mm(3) , 20% w/w solids) of solutions of maltodextrins of various dextrose equivalents (M040:DE6, M100:DE11, and M250:DE25.5), M100-sugars (1:1 glucose, fructose and sucrose), and agar for gelation with dispersed β-carotene were frozen at -20, -40, or -80 °C and freeze-dried. Glass transition and α-relaxation temperatures were determined with differential scanning calorimetry and dynamic mechanical analysis, respectively. β-Carotene contents were monitored spectrophotometrically. In the glassy solids, pore microstructure had a major effect on β-carotene stability. Small pores with thin walls and large surface area allowed β-carotene exposure to oxygen which led to a higher loss, whereas structural collapse enhanced stability of β-carotene by decreasing exposure to oxygen. As water plasticized matrices, an increase in molecular mobility in the matrix enhanced β-carotene degradation. Stability of dispersed β-carotene was highest at around 0.2 a(w) , but decreasing structural relaxation times above the glass transition correlated well with the rate of β-carotene degradation at higher a(w) . Microstructure, a(w) , and component mobility are important factors in the control of stability of β-carotene in freeze-dried solids. β-Carotene expresses various nutritional benefits; however, it is sensitive to oxygen and the degradation contributes to loss of nutritional values as well as product color. To increase stability of β-carotene in freeze-dried foods, the amount of oxygen penetration need to be limited. The modification of freeze-dried food structures, for example, porosity and structural collapse, components, and humidity effectively enhance the stability of dispersed β-carotene in freeze-dried solids. © 2012 Institute of Food Technologists®

  8. Structural determinants of hydration, mechanics and fluid flow in freeze-dried collagen scaffolds.

    Science.gov (United States)

    Offeddu, G S; Ashworth, J C; Cameron, R E; Oyen, M L

    2016-09-01

    Freeze-dried scaffolds provide regeneration templates for a wide range of tissues, due to their flexibility in physical and biological properties. Control of structure is crucial for tuning such properties, and therefore scaffold functionality. However, the common approach of modeling these scaffolds as open-cell foams does not fully account for their structural complexity. Here, the validity of the open-cell model is examined across a range of physical characteristics, rigorously linking morphology to hydration and mechanical properties. Collagen scaffolds with systematic changes in relative density were characterized using Scanning Electron Microscopy, X-ray Micro-Computed Tomography and spherical indentation analyzed in a time-dependent poroelastic framework. Morphologically, all scaffolds were mid-way between the open- and closed-cell models, approaching the closed-cell model as relative density increased. Although pore size remained constant, transport pathway diameter decreased. Larger collagen fractions also produced greater volume swelling on hydration, although the change in pore diameter was constant, and relatively small at ∼6%. Mechanically, the dry and hydrated scaffold moduli varied quadratically with relative density, as expected of open-cell materials. However, the increasing pore wall closure was found to determine the time-dependent nature of the hydrated scaffold response, with a decrease in permeability producing increasingly elastic rather than viscoelastic behavior. These results demonstrate that characterizing the deviation from the open-cell model is vital to gain a full understanding of scaffold biophysical properties, and provide a template for structural studies of other freeze-dried biomaterials. Freeze-dried collagen sponges are three-dimensional microporous scaffolds that have been used for a number of exploratory tissue engineering applications. The characterization of the structure-properties relationships of these scaffolds is

  9. Storage conditions affect oxidative stability and nutritional composition of freeze-dried Nannochloropsis salina

    DEFF Research Database (Denmark)

    Safafar, Hamed; Langvad, Sten; Møller, Peter

    2017-01-01

    composition of microalgae biomass. In order to investigate the worsening of the nutritional quality of freeze dried biomass, a multifactorial storage experiment was conducted on a high EPA (eicosapentaenoic acid) Nannochloropsis salina biomass. The storage time (0–56 days), storage temperature (5, 20,and 40...... °C and packaging conditions (under vacuum and ambient pressure)used as main factors. During the 56 days of storage, both time and temperature strongly influenced the oxidation reactions which result in deterioration of bioactive compounds such as carotenoids, tocopherols, and EPA. Lipid deterioration......, or cosmetics requires the knowledge of the optimum storage conditions to prevent the value-added compounds from deterioration. Results of this study improve our understanding of the chemical deterioration under different storage conditions and can help the producers/customers to extend the shelf life...

  10. Characteristics of Vacuum Freeze Drying with Utilization of Internal Cooling and Condenser Waste Heat for Sublimation

    Directory of Open Access Journals (Sweden)

    Muhammad Alhamid

    2013-09-01

    Full Text Available Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing by internal cooling prevents evaporation until the mass of the specimen is 0.47 g and promotes transition of the specimen into the solid phase.

  11. Freeze drying-assisted synthesis of Pt@reduced graphene oxide nanocomposites as excellent hydrogen sensor

    Science.gov (United States)

    Lu, Xiaojing; Song, Xinjie; Gu, Cuiping; Ren, Haibo; Sun, Yufeng; Huang, Jiarui

    2018-05-01

    Quick and efficient detection of low concentrations of hydrogen remains a challenge because of the stability of hydrogen. A sensor based on reduced oxide graphene functionalized with Pt nanoparticles is successfully fabricated using a freeze-drying method followed by heat treatment. The structure and morphology of the Pt@rGO nanocomposites are well analyzed by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The as-prepared Pt@rGO nanocomposites show excellent hydrogen gas sensing properties at a low working temperature of 50 °C. The sensitivity toward 0.5% hydrogen is 8%. The response and recovery times of the sensor exposed to 0.5% hydrogen are 63 and 104 s, respectively. The gas-sensing mechanism of Pt@rGO sensor is also discussed.

  12. Evaluation of 3D-Printed Polycaprolactone Scaffolds Coated with Freeze-Dried Platelet-Rich Plasma for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Junda Li

    2017-07-01

    Full Text Available Three-dimensional printing is one of the most promising techniques for the manufacturing of scaffolds for bone tissue engineering. However, a pure scaffold is limited by its biological properties. Platelet-rich plasma (PRP has been shown to have the potential to improve the osteogenic effect. In this study, we improved the biological properties of scaffolds by coating 3D-printed polycaprolactone (PCL scaffolds with freeze-dried and traditionally prepared PRP, and we evaluated these scaffolds through in vitro and in vivo experiments. In vitro, we evaluated the interaction between dental pulp stem cells (DPSCs and the scaffolds by measuring cell proliferation, alkaline phosphatase (ALP activity, and osteogenic differentiation. The results showed that freeze-dried PRP significantly enhanced ALP activity and the mRNA expression levels of osteogenic genes (ALP, RUNX2 (runt-related gene-2, OCN (osteocalcin, OPN (osteopontin of DPSCs (p < 0.05. In vivo, 5 mm calvarial defects were created, and the PRP-PCL scaffolds were implanted. The data showed that compared with traditional PRP-PCL scaffolds or bare PCL scaffolds, the freeze-dried PRP-PCL scaffolds induced significantly greater bone formation (p < 0.05. All these data suggest that coating 3D-printed PCL scaffolds with freeze-dried PRP can promote greater osteogenic differentiation of DPSCs and induce more bone formation, which may have great potential in future clinical applications.

  13. Effects of Freeze-Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages.

    Science.gov (United States)

    Eisinaite, Viktorija; Vinauskiene, Rimante; Viskelis, Pranas; Leskauskaite, Daiva

    2016-09-01

    The aim of this study was to compare the chemical composition of freeze-dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze-dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p products contained higher amounts of nitrates, total phenolic compounds and lower amounts of sucrose, parsnip had higher concentration of proteins, leek was rich in fat. The analysis of pH, water activity, lactic acid bacteria, coagulase-positive staphylococci and coliforms content showed that the incorporation of freeze-dried vegetables had no negative effect on the fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p products and control. Freeze-dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages. © 2016 Institute of Food Technologists®

  14. Inulin sugar glasses preserve the structural integrity and biological activity of influenza virosomes during freeze-drying and storage

    NARCIS (Netherlands)

    de Jonge, Jørgen; Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Wilschut, Jan; Huckriede, Anke; Frijlink, Henderik W.

    Influenza virosomes are reconstituted influenza virus envelopes that may be used as vaccines or as carrier systems for cellular delivery of therapeutic molecules. Here we present a procedure to generate influenza virosomes as a stable dry-powder formulation by freeze-drying (lyophilization) using an

  15. Fabrication of Li{sub 2}TiO{sub 3} pebbles by a freeze drying process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Jin, E-mail: lee@mokpo.ac.kr [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of); Park, Yi-Hyun [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Yu, Min-Woo [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of)

    2013-11-15

    Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by using a freeze drying process. The Li{sub 2}TiO{sub 3} slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li{sub 2}TiO{sub 3} pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined.

  16. The choice of a suitable oligosaccharide to prevent aggregation of PEGylated nanoparticles during freeze thawing and freeze drying

    NARCIS (Netherlands)

    Hinrichs, Wouter; Manceñido, F A; Sanders, N N; Braeckmans, K; De Smedt, S C; Demeester, J; Frijlink, H W

    2006-01-01

    In a previous Study we have shown that the oligosaccharide inulin can prevent aggregation of poly(ethylene glycol) (PEG) coated plasmid DNA/cationic liposome complexes ('' PEGylated lipoplexes '') during freeze thawing and freeze drying [Hinrichs et al., 2005. J. Control. Release 103, 465]. By

  17. Freeze-drying for controlled nanoparticle distribution in Co/SiO 2 Fischer–Tropsch catalysts

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; Munnik, P.; Talsma, H.; de Jongh, P.E.; de Jong, K.P.

    2013-01-01

    Controlling the nanoparticle distribution over a support is considered essential to arrive at more stable catalysts. By developing a novel freeze drying method, the nanoparticle distribution was successfully manipulated for the preparation of Co/SiO2 Fischer-Tropsch catalysts using a commercial

  18. NIR spectroscopy for the in-line monitoring of a multicomponent formulation during the entire freeze-drying process

    NARCIS (Netherlands)

    Rosas, Juan G; de Waard, Hans; De Beer, Thomas; Vervaet, Chris; Remon, Jean Paul; Hinrichs, Wouter L J; Frijlink, Henderik W; Blanco, Marcel

    2014-01-01

    Freeze drying is a complex, time consuming and thus expensive process, hence creating a need for understanding the material behaviour in the process environment and for process optimization. Near-infrared (NIR) spectroscopy offers the opportunity to monitor physicochemical changes of the formulation

  19. A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation

    NARCIS (Netherlands)

    Saluja, V.; Amorij, J-P.; Kapteyn, J. C.; de Boer, A. H.; Frijlink, H. W.; Hinrichs, W. L. J.

    2010-01-01

    The aim of this study was to investigate two different processes to produce a stable influenza subunit vaccine powder for pulmonary immunization i.e. spray drying (SD) and spray freeze drying (SFD). The formulations were analyzed by proteolytic assay, single radial immunodiffusion assay (SRID),

  20. Effects of different rearing and feeding systems on lipid oxidation and antioxidant capacity of freeze-dried egg yolks.

    Science.gov (United States)

    Pignoli, Giovanni; Rodriguez-Estrada, Maria Teresa; Mandrioli, Mara; Barbanti, Lorenzo; Rizzi, Laura; Lercker, Giovanni

    2009-12-23

    Lipid oxidation and antioxidant capacity of freeze-dried egg yolks produced with two rearing systems (battery cages and free-range) and two types of feedings (conventional and organic) were studied. Nine fresh egg yolks of each crossed treatment were pooled, frozen for a month, freeze-dried, vacuum-packed, and kept at -18 degrees C until analysis. No significant differences were observed in the lipid (58.0-62.1%) and total sterol contents (33.0-35.5 g/kg of lipids) of the freeze-dried egg yolks. Free rearing and conventional feeding systems resulted in significantly higher total tocopherol, alpha-tocopherol, and lutein contents, as compared to the battery cage and the organic feed, respectively. However, no significant differences were found in lipid oxidation (peroxide value = 0.7-0.9 mequiv of O(2)/kg of fat; thiobarbituric reactive substances = 1.0-1.3 mg of malonylaldehyde/kg of sample) and cholesterol oxidation (28.8-43.5 mg of cholesterol oxidation products/kg of lipids; 0.08-0.12% oxidized cholesterol) of freeze-dried egg yolks except for 7alpha-hydroxycholesterol, which was significantly lower in samples obtained with organic feed.

  1. First steps towards tissue engineering of small-diameter blood vessels: preparation of flat scaffolds of collagen and elastin by means of freeze drying

    NARCIS (Netherlands)

    Buttafoco, L.; Engbers-Buijtenhuijs, P.; Poot, Andreas A.; Dijkstra, Pieter J.; Daamen, W.F.; van Kuppevelt, T.H.; Vermes, I.; Feijen, Jan

    2006-01-01

    Porous scaffolds composed of collagen or collagen and elastin were prepared by freeze drying at temperatures between -18 and -196°C. All scaffolds had a porosity of 90-98% and a homogeneous distribution of pores. Freeze drying at -18°C afforded collagen and collagen/elastin matrices with average

  2. Fibres as carriers for Lactobacillus rhamnosus during freeze-drying and storage in apple juice and chocolate-coated breakfast cereals.

    Science.gov (United States)

    Saarela, Maria; Virkajärvi, Ilkka; Nohynek, Liisa; Vaari, Anu; Mättö, Jaana

    2006-11-01

    The capability of different fibre preparations to protect the viability and stability of Lactobacillus rhamnosus during freeze-drying, storage in freeze-dried form and after formulation into apple juice and chocolate-coated breakfast cereals was studied. In freeze-drying trials wheat dextrin and polydextrose proved to be promising carriers for the L. rhamnosus strains: both freeze-drying survival and storage stability at 37 degrees C were comparable to the control carrier (sucrose). Using apple fibre and inulin carriers resulted in powders with fairly good initial freeze-drying survival but with poor storage stability at 37 degrees C. When fresh L. rhamnosus cells were added into apple juice (pH 3.5) together with oat flour with 20% beta-glucan the survival of the cells was much better at 4 degrees C and at 20 degrees C than with sucrose, wheat dextrin and polydextrose, whereas with freeze-dried cells no protective effect of oat flour could be seen. The stability of freeze-dried L. rhamnosus cells at 20 degrees C was higher in chocolate-coated breakfast cereals compared to low pH apple juice. Similar to freeze-drying stability, wheat dextrin and polydextrose proved to be better carriers than oat flour in chocolate-coated breakfast cereals. Regardless of their differing capability to adhere to fibre preparations the two L. rhamnosus strains studied gave parallel results in the stability studies with different carriers.

  3. Controlled Crystallization of the Lipophilic Drug Fenofibrate During Freeze-Drying : Elucidation of the Mechanism by In-Line Raman Spectroscopy

    NARCIS (Netherlands)

    de Waard, Hans; De Beer, Thomas; Hinrichs, Wouter L J; Vervaet, Chris; Remon, Jean-Paul; Frijlink, Henderik W

    2010-01-01

    We developed a novel process, "controlled crystallization during freeze-drying" to produce drug nanocrystals of poorly water-soluble drugs. This process involves freeze-drying at a relatively high temperature of a drug and a matrix material from a mixture of tertiary butyl alcohol and water,

  4. Stability of buffer-free freeze-dried formulations: A feasibility study of a monoclonal antibody at high protein concentrations.

    Science.gov (United States)

    Garidel, Patrick; Pevestorf, Benjamin; Bahrenburg, Sven

    2015-11-01

    We studied the stability of freeze-dried therapeutic protein formulations over a range of initial concentrations (from 40 to 160 mg/mL) and employed a variety of formulation strategies (including buffer-free freeze dried formulations, or BF-FDF). Highly concentrated, buffer-free liquid formulations of therapeutic monoclonal antibodies (mAbs) have been shown to be a viable alternative to conventionally buffered preparations. We considered whether it is feasible to use the buffer-free strategy in freeze-dried formulations, as an answer to some of the known drawbacks of conventional buffers. We therefore conducted an accelerated stability study (24 weeks at 40 °C) to assess the feasibility of stabilizing freeze-dried formulations without "classical" buffer components. Factors monitored included pH stability, protein integrity, and protein aggregation. Because the protein solutions are inherently self-buffering, and the system's buffer capacity scales with protein concentration, we included highly concentrated buffer-free freeze-dried formulations in the study. The tested formulations ranged from "fully formulated" (containing both conventional buffer and disaccharide stabilizers) to "buffer-free" (including formulations with only disaccharide lyoprotectant stabilizers) to "excipient-free" (with neither added buffers nor stabilizers). We evaluated the impacts of varying concentrations, buffering schemes, pHs, and lyoprotectant additives. At the end of 24 weeks, no change in pH was observed in any of the buffer-free formulations. Unbuffered formulations were found to have shorter reconstitution times and lower opalescence than buffered formulations. Protein stability was assessed by visual inspection, sub-visible particle analysis, protein monomer content, charge variants analysis, and hydrophobic interaction chromatography. All of these measures found the stability of buffer-free formulations that included a disaccharide stabilizer comparable to buffer

  5. Effects of Radiosterilization on Sealed Aqueous Solutions

    International Nuclear Information System (INIS)

    Pandula, E.L.; Farkas, E.; Rácz, I.

    1967-01-01

    For aqueous solutions sensitive to heat,and in connection with the use of plastic ampoules, the need for applying radiosterilization is growing. Studying the possibilities of radiosterilization, experiments were made with the following: 0.1% atropine, 1.0% morphine, and 2% lidocain in aqueous solutions. The aim of the work was to establish whether the active ingredients of the injections suffer decomposition or not, to study the factors influencing the degradation and, furthermore, to make attempts to prevent decomposition. The samples were irradiated by 420 Ci 60 Co γ-radiation source. The applied doses were 1 to 2.5 Mrad, with a 10 4 to 2.5 x 10 5 rad/h dose intensity. After irradiation the change in colour, pH-value, concentration and UV-spectra were studied. Changes of the last three types were found. Studying the factors influencing decomposition it has been found that the degree of degradation was increased by the increase of radiation dose, increase of concentration, decrease of dose intensity, and increase of oxygen content in the atmosphere over the solution. Attempts were made to prevent degradation. Solutions were prepared with sulphite, ascorbic acid, and AET, and some measure of success was achieved, especially with the sulphite addition. (author)

  6. Present studies on the radio-sterilized drugs

    International Nuclear Information System (INIS)

    Marciniec, B.; Dettlaff, K.

    2007-01-01

    Lecture presents present status of radiosterilization of drugs and medical materials as compared to other sterilization methods. Literature review is shown on degradation of different kinds of drugs sterilized upon action of the sterilising doses of radiation

  7. International regulations concerning radiosterilization; Aktualne przepisy miedzynarodowe dotyczace sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Kaluska, I [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    European norms (EN 552) and international regulations (ISO 11137) concerning commercial radiosterilization have been described. Licensing of irradiation installation as well as sterilization procedure requirements, and routine control have been discussed in detail. 3 refs.

  8. Sample preservation for determination of organic compounds: microwave versus freeze-drying

    International Nuclear Information System (INIS)

    Popp, M.; Lied, W.; Meyer, A.J.; Richter, A.; Schiller, P.; Schwitte, H.

    1996-01-01

    In search of a reliable drying method, which might be used even under field conditions, microwave drying was compared to freeze-drying of plant material. Leaves of Ananas comosus and Avicennia germinans as well as buds and phloem of Acer pseudoplatanus were used and checked for one or more of the following substances: sugars, sugar alcohols, organic and amino acids, total nitrogen, and glycinebetaine. With most samples good agreement was achieved between the two drying methods. Only in the case of the Ananas comosus leaves, which exhibited low pH and high water content, did appreciable differences occur in organic and amino acids. Besides that, sucrose was the compound most susceptible to alterations, which was especially evident when leaves of Sambucus nigra were dried in the two different compartments (condenser compartment, drying bell jar) of the freeze-dryer in use. For Ananas comosus leaf samples it was shown that microwaving can also be used prior to extraction of tissue sap. (author)

  9. ALVEOLAR BONE REGENERATION AFTER DEMINERALIZED FREEZE DRIED BONE ALOGRAFT (DFDBA BONE GRAFTING

    Directory of Open Access Journals (Sweden)

    Sri Oktawati

    2006-04-01

    Full Text Available Periodontal treatment by conventional way will result in healing repair, which easily cause recurrence. Modification of treatment should be done to get an effective result, that is the regeneration of alveolar bone and to reduce inflammation. The objective of this study is to determine the alveolar bone regeneration after using DFDBA (Demineralized Freeze Dried Bone Allograft. Quasi experimental designs with pre and post test method was used in this study. From 13 patients, 26 defects got conventional or regenerative treatment. The indicator of alveolar bone regenaration in bone height in radiographic appearance and level of osteocalsin in gingival crevicular fluid (GCF were checked before and after the treatment, then the changes that occurred were analyzed. The result of the research showed that alveolar bone regeneration only occurred to the group of regenerative treatment using DFDBA. The conclusion is the effective periodontal tissue regeneration occurred at regenerative treatment by using DFDBA, and the osteocalsin in GCF can be used as indicator of bone growth.

  10. Stability of freeze-dried vaginal Lactobacillus strains in the presence of different lyoprotectors.

    Science.gov (United States)

    Juárez Tomás, María Silvina; Bru, Elena; Martos, Gladys; Nader-Macías, María Elena

    2009-05-01

    The industrial use of lactic acid bacteria as probiotic cultures depends on the preservation techniques employed, which are required to guarantee stable cultures in terms of viability and functional activity. The aim of this study was to evaluate the effects of 12% lactose and 12% sucrose suspended in water or reconstituted skim milk on the survival and expression of beneficial characteristics during freeze-drying and subsequent storage of 6 vaginal lactobacilli strains. A cubic polynomial model was also used for the first time to evaluate the effects of different protectors on survival behavior during storage. Different survival patterns were observed among the strains considered. The presence of both lactose and sucrose in water or in 6% skim milk as the suspension medium proved to be effective in maintaining a high degree of survival and expression of potentially probiotic characteristics (production of antimicrobial substances or auto-aggregation capabilities) of most strains after lyophilization and long-term storage. This study constitutes a valuable step to obtain concentrated cultures with the highest stability of microorganisms for pharmaceutical purposes.

  11. Sterilization of freeze dried manila clam (Ruditapea philippinarum) porridge for immuno-compromised patients

    International Nuclear Information System (INIS)

    Song, Beom Seok; Park, Jae Nam

    2017-01-01

    This study was conducted to evaluate the combined effect of gamma irradiation and different conditions (vacuum packaging, antioxidant and freezing) on the microbiological and sensory characteristics of freeze dried Manila clam porridge (MCP) for immuno-compromised patient food. McP can be sterilized at 1 kGy to 10 kGy. the initial counts of total aerobic bacteria and yeast molds in the non-irradiated MCP were 2.4±0.5 and 1.2±0.3 log CFU g"-'1, respectively, but gamma irradiation significantly decreased the total aerobic bacteria to below the detection limit (1 log CFU g"-"1) (5 kGy). Moreover, gamma irradiation effectively eliminated yeasts/molds at dose below than 1 kGy. However, gamma irradiation accelerated the increase of lipid oxidation and therefore, decreased the sensory characteristics of MCP as irradiation dose increased. to improve the sensory qualities of gamma irradiated MCP, combination treatment (vacuum packaging, 0.1% vitamin c) were applied. there was no significant difference in the overall acceptance scores between the combined-treatment sample (5.6 points) and the non-irradiated samples (6.0). the results indicate that combination treatment (vacuum packaging, 0.1% vitamin c) may help to maintain the quality of MCP. therefore, it considered that irradiation of MCP with combined treatment and this is an effective method for the consumption as a special purpose food such as for space travel or immuno-compromised patients

  12. Multi-scale mechanical response of freeze-dried collagen scaffolds for tissue engineering applications.

    Science.gov (United States)

    Offeddu, Giovanni S; Ashworth, Jennifer C; Cameron, Ruth E; Oyen, Michelle L

    2015-02-01

    Tissue engineering has grown in the past two decades as a promising solution to unresolved clinical problems such as osteoarthritis. The mechanical response of tissue engineering scaffolds is one of the factors determining their use in applications such as cartilage and bone repair. The relationship between the structural and intrinsic mechanical properties of the scaffolds was the object of this study, with the ultimate aim of understanding the stiffness of the substrate that adhered cells experience, and its link to the bulk mechanical properties. Freeze-dried type I collagen porous scaffolds made with varying slurry concentrations and pore sizes were tested in a viscoelastic framework by macroindentation. Membranes made up of stacks of pore walls were indented using colloidal probe atomic force microscopy. It was found that the bulk scaffold mechanical response varied with collagen concentration in the slurry consistent with previous studies on these materials. Hydration of the scaffolds resulted in a more compliant response, yet lesser viscoelastic relaxation. Indentation of the membranes suggested that the material making up the pore walls remains unchanged between conditions, so that the stiffness of the scaffolds at the scale of seeded cells is unchanged; rather, it is suggested that thicker pore walls or more of these result in the increased moduli for the greater slurry concentration conditions. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Spray Freeze-drying - The Process of Choice for Low Water Soluble Drugs?

    International Nuclear Information System (INIS)

    Leuenberger, H.

    2002-01-01

    Most of the novel highly potent drugs, developed on the basis of modern molecular medicine, taking into account cell surface recognition techniques, show poor water solubility. A chemical modification of the drug substance enhancing the solubility often decreases the pharmacological activity. Thus, as an alternative an increase of the solubility can be obtained by the reduction of the size of the drug particles. Unfortunately, it is often difficult to obtain micro or nanosized drug particles by classical or more advanced crystallization using supercritical gases or by milling techniques. In addition, nanosized particles are often not physically stable and need to be stabilized in an appropriate matrix. Thus, it may be of interest to manufacture directly nanosized drug particles stabilized in an inert hydrophilic matrix, i.e. nanostructured and nanocomposite systems. Solid solutions and solid dispersions represent nanostructured and nanocomposite systems. In this context, the use of the vacuum-fluidized-bed technique for the spray-drying of a low water soluble drug cosolubilized with a hydrophilic excipient in a polar organic solvent is discussed. In order to avoid the use of organic solvents, a special spray-freeze-drying technique working at atmospheric pressure is presented. This process is very suitable for temperature and otherwise sensitive drugs such as pharmaproteins

  14. Effects of freezing, freeze drying and convective drying on in vitro gastric digestion of apples.

    Science.gov (United States)

    Dalmau, Maria Esperanza; Bornhorst, Gail M; Eim, Valeria; Rosselló, Carmen; Simal, Susana

    2017-01-15

    The influence of processing (freezing at -196°C in liquid N2, FN sample; freeze-drying at -50°C and 30Pa, FD sample; and convective drying at 60°C and 2m/s, CD sample) on apple (var. Granny Smith) behavior during in vitro gastric digestion was investigated. Dried apples (FD and CD samples) were rehydrated prior to digestion. Changes in carbohydrate composition, moisture, soluble solids, acidity, total polyphenol content (TPC), and antioxidant activity (AA) of apple samples were measured at different times during digestion. Processing resulted in disruption of the cellular structure during digestion, as observed by scanning electron microscopy, light microscopy, and changes in carbohydrate composition. Moisture content increased (6-11% dmo), while soluble solids (55-78% dmo), acidity (44-72% dmo), total polyphenol content (30-61% dmo), and antioxidant activity (41-87%) decreased in all samples after digestion. Mathematical models (Weibull and exponential models) were used to better evaluate the influence of processing on apple behavior during gastric digestion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. DEHYDRATION OF CHEESE BY HOT AIR, MICROWAVE AND FREEZE-DRYING

    Directory of Open Access Journals (Sweden)

    ANA RITA C. PINHO

    2017-12-01

    Full Text Available The objective of this work was to study the dehydration of skim cheese through different methods, in particular by hot air, microwave and freeze-drying, in order to assess which of these methods would be more suitable for the development of a new product (cheese snack. For the three processes of dehydration, several temperatures, powers and times were used, respectively. The drying time was optimized to allow the water activity of the final product to be between 0.3 and 0.4. The color and texture of the product obtained by the three processes were evaluated, and the nutritional analysis (protein, lipids, ash of the product dried by hot air at 52 ºC and by microwave at 750 W and 850 W was performed. The sensory analysis of the microwave dehydrated products was also carried out. The results obtained revealed that the temperature played a relevant role in the drying time and the hardness of the product. In the dehydration by microwave, the power of 850 W resulted in a lower drying time and a better color preservation, but in a high hardness of the samples. Among the three processes studied, the microwave drying was the fastest for the water removal from the cheese.

  16. Freeze-dried plasma at the point of injury: from concept to doctrine.

    Science.gov (United States)

    Glassberg, Elon; Nadler, Roy; Gendler, Sami; Abramovich, Amir; Spinella, Philip C; Gerhardt, Robert T; Holcomb, John B; Kreiss, Yitshak

    2013-12-01

    While early plasma transfusion for the treatment of patients with ongoing major hemorrhage is widely accepted as part of the standard of care in the hospital setting, logistic constraints have limited its use in the out-of-hospital setting. Freeze-dried plasma (FDP), which can be stored at ambient temperatures, enables early treatment in the out-of-hospital setting. Point-of-injury plasma transfusion entails several significant advantages over currently used resuscitation fluids, including the avoidance of dilutional coagulopathy, by minimizing the need for crystalloid infusion, beneficial effects on endothelial function, physiological pH level, and better maintenance of intravascular volume compared with crystalloid-based solutions. The Israel Defense Forces Medical Corps policy is that plasma is the resuscitation fluid of choice for selected, severely wounded patients and has thus included FDP as part of its armamentarium for use at the point of injury by advanced life savers, across the entire military. We describe the clinical rationale behind the use of FDP at the point-of-injury, the drafting of the administration protocol now being used by Israel Defense Forces advanced life support providers, the process of procurement and distribution, and preliminary data describing the first casualties treated with FDP at the point of injury. It is our hope that others will be able to learn from our experience, thus improving trauma casualty care around the world.

  17. Apoptosis-like death was involved in freeze-drying-preserved fungus Mucor rouxii and can be inhibited by L-proline.

    Science.gov (United States)

    Wang, Xiaoyun; Wang, Youzhi

    2016-02-01

    Freeze-drying is one of the most effective methods to preserve fungi for an extended period. However, it is associated with a loss of viability and shortened storage time in some fungi. This study evaluated the stresses that led to the death of freeze-dried Mucor rouxii by using cell apoptotic methods. The results showed there were apoptosis-inducing stresses, such as the generation of obvious intracellular reactive oxygen species (ROS) and metacaspase activation. Moreover, nuclear condensation and a delayed cell death peak were determined after rehydration and 24 h incubation in freeze-dried M. rouxii via a propidium iodide (PI) assay, which is similar to the phenomenon of cryopreservation-induced delayed-onset cell death (CIDOCD). Then, several protective agents were tested to decrease the apoptosis-inducing stresses and to improve the viability. Finally, it was found that 1.6 mM L-proline can effectively decrease the nuclear condensation rate and increase the survival rate in freeze-dried M. rouxii. (1) apoptosis-inducing factors occur in freeze-dried M. rouxii. (2) ROS and activated metacaspases lead to death in freeze-dried M. rouxii. (3)L-proline increases the survival rate of freeze-dried M. rouxii. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens.

    Science.gov (United States)

    Fombong, Forkwa Tengweh; Van Der Borght, Mik; Vanden Broeck, Jozef

    2017-09-16

    The longhorn grasshopper, Ruspolia differens (Serville), plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying), employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November-December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44%) and palmitic acid (28%) were the two most abundant fatty acids; while the presence of arachidonic acid (0.6%) and docosahexaenoic acid (0.21%) suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896-1035 mg/100 g), potassium (779-816 mg/100 g) and phosphorus (652-685 mg/100 g) were quite high among the minerals. The presence of the trace elements iron (217-220 mg/100 g), zinc (14.2-14.6 mg/100 g), manganese (7.4-8.3 mg/100 g) and copper (1.66 mg/100 g) suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes.

  19. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens

    Directory of Open Access Journals (Sweden)

    Forkwa Tengweh Fombong

    2017-09-01

    Full Text Available The longhorn grasshopper, Ruspolia differens (Serville, plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying, employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November–December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44% and palmitic acid (28% were the two most abundant fatty acids; while the presence of arachidonic acid (0.6% and docosahexaenoic acid (0.21% suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896–1035 mg/100 g, potassium (779–816 mg/100 g and phosphorus (652–685 mg/100 g were quite high among the minerals. The presence of the trace elements iron (217–220 mg/100 g, zinc (14.2–14.6 mg/100 g, manganese (7.4–8.3 mg/100 g and copper (1.66 mg/100 g suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes.

  20. Rapid formation of phase-clean 110 K (Bi-2223) powders derived via freeze-drying process

    Science.gov (United States)

    Balachandran, U.

    1996-06-04

    A process for the preparation of amorphous precursor powders for Pb-doped Bi{sub 2}Sr{sub 2} Ca{sub 2}Cu{sub 3}O{sub x} (2223) includes a freeze-drying process incorporating a splat-freezing step. The process generally includes splat freezing a nitrate solution of Bi, Pb, Sr, Ca, and Cu to form flakes of the solution without any phase separation; grinding the frozen flakes to form a powder; freeze-drying the frozen powder; heating the dried powder to form a dry green precursor powders; denitrating the green-powders; heating the denitrated powders to form phase-clean Bi-2223 powders. The grain boundaries of the 2223 grains appear to be clean, leading to good intergrain contact between 2223 grains. 11 figs.

  1. Detecting phase separation of freeze-dried binary amorphous systems using pair-wise distribution function and multivariate data analysis

    DEFF Research Database (Denmark)

    Chieng, Norman; Trnka, Hjalte; Boetker, Johan

    2013-01-01

    The purpose of this study is to investigate the use of multivariate data analysis for powder X-ray diffraction-pair-wise distribution function (PXRD-PDF) data to detect phase separation in freeze-dried binary amorphous systems. Polymer-polymer and polymer-sugar binary systems at various ratios were...... freeze-dried. All samples were analyzed by PXRD, transformed to PDF and analyzed by principal component analysis (PCA). These results were validated by differential scanning calorimetry (DSC) through characterization of glass transition of the maximally freeze-concentrate solute (Tg'). Analysis of PXRD......-PDF data using PCA provides a more clear 'miscible' or 'phase separated' interpretation through the distribution pattern of samples on a score plot presentation compared to residual plot method. In a phase separated system, samples were found to be evenly distributed around the theoretical PDF profile...

  2. Biophysical evaluation of aminoclay as an effective protectant for protein stabilization during freeze-drying and storage

    Directory of Open Access Journals (Sweden)

    Song JG

    2016-12-01

    Full Text Available Jae Geun Song, Sang Hoon Lee, Hyo-Kyung Han College of Pharmacy, Dongguk University, Goyang, South Korea Abstract: This study aimed to evaluate aminoclay (3-aminopropyl-functionalized magnesium phyllosilicate as an effective protectant for the stabilization of protein formulation in freeze-drying. Bovine serum albumin (BSA, as a model protein, was freeze-dried with aminoclay at various concentrations, and the effects of aminoclay on the structural stability of proteins were compared with those of the conventional stabilizers. The structural characteristics of the protein were determined by size exclusion chromatography (SEC, circular dichroism (CD, and Fourier transform infrared (FTIR spectroscopy. Furthermore, physicochemical and morphological characteristics were examined by X-ray powder diffraction (XRPD, differential scanning calorimetry (DSC, and scanning electron microscopy (SEM. XRPD and DSC patterns indicated that the glass transition temperature (Tg of the amorphous formulation of aminoclay mixed with proteins was gradually elevated as the concentration of aminoclay increased. FTIR and CD spectral analysis suggested that the protein structure was well maintained with aminoclay during the freeze-drying process and 3 months of storage at 4°C and 40°C. Furthermore, aminoclay conferred the greatest protection against aggregation and retained the monomer content of BSA even at a high temperature. The morphological characteristics of lyophilized proteins were also well conserved during the storage with aminoclay. These results suggested that aminoclay may be useful as an alternative stabilizer for maintaining the structural stability of protein formulations. Keywords: aminoclay, cryoprotectant, lyoprotectant, freeze-drying, protein, stability

  3. Effect of freeze-dried leek powder (FDLP) and nitrite level on processing and quality characteristics of fermented sausages.

    Science.gov (United States)

    Tsoukalas, D S; Katsanidis, E; Marantidou, S; Bloukas, J G

    2011-02-01

    Fermented sausages were produced with 0.84% and 1.68% freeze-dried leek powder (FDLP), providing 75 and 150 mg/kg NaNO(3), respectively, and three levels of added nitrite (0, 75, and 150 mg/kg NaNO(2). A control treatment was also produced with 150 mg/kg NaNO(2). Sausages with FDLP were darker and yellower (pnitrite. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Stabilization of protein by freeze-drying in the presence of trehalose: a case study of tubulin

    Czech Academy of Sciences Publication Activity Database

    Dráber, Pavel; Sulimenko, Vadym; Sulimenko, Tetyana; Dráberová, Eduarda

    2014-01-01

    Roč. 1129, February (2014), s. 443-458 ISSN 1064-3745 R&D Projects: GA MŠk LH12050; GA AV ČR M200521203; GA ČR GAP302/10/1701; GA ČR GPP302/11/P709 Institutional support: RVO:68378050 Keywords : Freeze-drying * Microtubules * Stability * Trehalose * Tubulin Subject RIV: EB - Genetics ; Molecular Biology

  5. Preparation of a ceramic superconductor from ultrafine particles by freeze-dry process in Ba-Y-Cu-O system

    International Nuclear Information System (INIS)

    Chen Zuyao; Qian Yitai; Wan Yanjian; Rong Jingfang; Zhang Han; Pan Guoqiang; Zhao Yong; Zhang Qirui

    1989-01-01

    Freeze-dry technique is first reported for preparing ceramic ultrafines. The single-phase complex oxide Ba 2 YCu 3 O/sub 9-δ/, a poly-crystallized compound, and ceramic superconductor have been synthesized successfully. The experimental results show that not only is the ceramic superconductor obtained uniform with fine particles and excellent superconductivity, but the conditions for solid reactions are relatively limited

  6. Identification of Components or Fractions Associated with Adverse Changes in Freeze Dried Chicken and Pork during Storage

    Science.gov (United States)

    1978-06-01

    objective of which was to further define and correlate the majur physical, chemical. and sensory changes which occur during the storage deterioration of pr...changes in freeze-dried chicken and pork during high temper-ao -r ature, oxygen-free storage. This effort was undertaken as part of the U.S. Air Force ...for 20 minutes, drained for five minutes, and weighed. Water was expressed from the rehydrated samples by a 500-kg Instron activated force acting

  7. Recent developments in high efficient freeze-drying of fruits and vegetables assisted by microwave: A review.

    Science.gov (United States)

    Fan, Kai; Zhang, Min; Mujumdar, Arun S

    2018-01-10

    Microwave heating has been applied in the drying of high-value solids as it affords a number of advantages, including shorter drying time and better product quality. Freeze-drying at cryogenic temperature and extremely low pressure provides the advantage of high product quality, but at very high capital and operating costs due partly to very long drying time. Freeze-drying coupled with a microwave heat source speeds up the drying rate and yields good quality products provided the operating unit is designed and operated to achieve the potential for an absence of hot spot developments. This review is a survey of recent developments in the modeling and experimental results on microwave-assisted freeze-drying (MFD) over the past decade. Owing to the high costs involved, so far all applications are limited to small-scale operations for the drying of high-value foods such as fruits and vegetables. In order to promote industrial-scale applications for a broader range of products further research and development efforts are needed to offset the current limitations of the process. The needs and opportunities for future research and developments are outlined.

  8. SOS gene induction and possible mutagenic effects of freeze-drying in Escherichia coli and Salmonella typhimurium.

    Science.gov (United States)

    Rosen, Rachel; Buchinger, Sebastian; Pfänder, Ramona; Pedhazur, Rami; Reifferscheid, Georg; Belkin, Shimshon

    2016-11-01

    We report the results of a study of the potential negative effects of the freeze-drying process, normally considered a benign means for long-term conservation of living cells and the golden standard in bacterial preservation. By monitoring gene induction using a whole-cell Escherichia coli bioreporter panel, in which diverse stress-responsive gene promoters are fused to luminescent or fluorescent reporting systems, we have demonstrated that DNA repair genes belonging to the SOS operon (recA, sulA, uvrA, umuD, and lexA) were induced upon resuscitation from the freeze-dried state, whereas other stress-responsive promoters such as grpE, katG, phoA, soxS, and sodA were not affected. This observation was confirmed by the UMU-chromotest (activation of the umuD gene promoter) in Salmonella typhimurium, as well as by real-time PCR analyses of selected E. coli SOS genes. We further show that a functional SOS operon is important in viability maintenance following resuscitation, but that at the same time, this repair system may introduce significantly higher mutation rates, comparable to those induced by high concentrations of a known mutagen. Our results also indicate that the entire freeze-drying process, rather than either freezing or drying separately, is instrumental in the induction of DNA damage.

  9. Spray-Freeze Drying: a Suitable Method for Aerosol Delivery of Antibodies in the Presence of Trehalose and Cyclodextrins.

    Science.gov (United States)

    Pouya, Maryam Amini; Daneshmand, Behnaz; Aghababaie, Shabnam; Faghihi, Homa; Vatanara, Alireza

    2018-05-08

    We aimed to prepare spray-freeze-dried powder of IgG considering physicochemical stability and aerodynamic aspects. Spray-freeze drying (SFD) exposes proteins to various stresses which should be compensated by suitable stabilizers. The competence of cyclodextrins (CDs), namely beta-cyclodextrin (βCD) and hydroxypropyl βCD (HPβCD), at very low concentrations, was investigated in the presence of separate mannitol- and trehalose-based formulations. Spray-freeze-dried preparations were quantified in terms of monomer recovery and conformation by size exclusion chromatography (SEC-HPLC) and Fourier transform infrared (FTIR) spectroscopy, respectively. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) were employed to identify the thermal characteristics of powders. Particle morphology was visualized by scanning electron microscopy (SEM). Aerodynamic behavior of powders was checked through an Anderson cascade impactor (ACI). Although all formulations protected antibody from aggregation during the SFD process (aggregation < 1%), mannitol-containing ones failed upon the storage (19.54% in the worst case). Trehalose-HPβCD incomparably preserved the formulation with fine particle fraction (FPF) of 51.29%. Crystallization of mannitol resulted in IgG destabilization upon storage. Although employed concentration of CDs is too low (less than 50:1 molar ratio to protein), they successfully served as stabilizing agents in SFD with perfect improvement in aerosol functionality. Graphical Abstract ᅟ.

  10. Effects of sugar alcohol and proteins on the survival of Lactobacillus bulgaricus LB6 during freeze drying.

    Science.gov (United States)

    Chen, He; Chen, Shiwei; Chen, Hongli; Wu, Yanyan; Shu, Guowei

    2015-01-01

    Lactobacillus bulgaricus LB6 is a bacterium which was selected in the commercial yoghurt with high angiotensin converting enzyme (ACE) inhibitory activity. Preparation of concentrated starter cultures via freeze drying is of practical importance to dairy and food industries. We optimized the optimal sugar alcohol and proteins for Lactobacillus bulgaricus LB6 during the process of freeze drying using a Plackett-Burman design. In our initial tests survival rate and the number of viable cells were associated with the type of lyoprotectant used and so our optimization protocol focused on increasing survival rate. Substances that had previously had a protective effect during freeze drying were investigated, for example: mannitol, sorbitol, xylitol, meso-erythritol, lactitol, whey protein isolate 90, bovine serum albumin, and whey protein concentrate 80 and soy protein isolate 70. We found that the optimum sugar alcohol and proteins for survival of Lactobacillus bulgaricus LB6 were whey protein concentrate (p = 0.0040 for survival rate), xylitol (p = 0.0067 for survival rate) and sorbitol (p = 0.0073 for survival rate), they showed positive effect (whey protein concentrate and sorbitol) or negative effect (xylitol). The effectiveness of three chosen sugar alcohols and protein implied that they could be used as lyoprotectant for Lactobacillus bulgaricus LB6 in the further research, the optimal composition of sugar alcohol and protein for the lyoprotectant use must be established.

  11. Potential of Near-Infrared Chemical Imaging as Process Analytical Technology Tool for Continuous Freeze-Drying.

    Science.gov (United States)

    Brouckaert, Davinia; De Meyer, Laurens; Vanbillemont, Brecht; Van Bockstal, Pieter-Jan; Lammens, Joris; Mortier, Séverine; Corver, Jos; Vervaet, Chris; Nopens, Ingmar; De Beer, Thomas

    2018-04-03

    Near-infrared chemical imaging (NIR-CI) is an emerging tool for process monitoring because it combines the chemical selectivity of vibrational spectroscopy with spatial information. Whereas traditional near-infrared spectroscopy is an attractive technique for water content determination and solid-state investigation of lyophilized products, chemical imaging opens up possibilities for assessing the homogeneity of these critical quality attributes (CQAs) throughout the entire product. In this contribution, we aim to evaluate NIR-CI as a process analytical technology (PAT) tool for at-line inspection of continuously freeze-dried pharmaceutical unit doses based on spin freezing. The chemical images of freeze-dried mannitol samples were resolved via multivariate curve resolution, allowing us to visualize the distribution of mannitol solid forms throughout the entire cake. Second, a mannitol-sucrose formulation was lyophilized with variable drying times for inducing changes in water content. Analyzing the corresponding chemical images via principal component analysis, vial-to-vial variations as well as within-vial inhomogeneity in water content could be detected. Furthermore, a partial least-squares regression model was constructed for quantifying the water content in each pixel of the chemical images. It was hence concluded that NIR-CI is inherently a most promising PAT tool for continuously monitoring freeze-dried samples. Although some practicalities are still to be solved, this analytical technique could be applied in-line for CQA evaluation and for detecting the drying end point.

  12. Response Surface Optimization of Lyoprotectant from Amino Acids and Salts for Bifidobacterium Bifidum During Vacuum Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Qi Kangru

    2017-12-01

    Full Text Available High quality probiotic powder can lay the foundation for the commercial production of functional dairy products. The freeze-drying method was used for the preservation of microorganisms, having a deleterious effect on the microorganisms viability. In order to reduce the damage to probiotics and to improve the survival rate of probiotics during freeze-drying, the Response Surface Methodology (RSM was adopted in this research to optimize lyoprotectant composed of amino acids (glycine, arginine and salts (NaHCO3 and ascorbic acid. Probiotic used was Bifidobacterium bifidum BB01. The regression model (p<0.05 was obtained by Box–Behnken experiment design, indicating this model can evaluate the freeze-drying survival rate of B. bifidum BB01 under different lyoprotectants. The results indicated these concentrations as optimal (in W/V: glycine 4.5%, arginine 5.5%, NaHCO3 0.8% and ascorbic acid 2.3%, respectively. Under these optimal conditions, the survival rate of lyophilized powder of B. bifidum BB01 was significantly increased by 80.9% compared to the control group (6.9±0.62%, the results were agreement with the model prediction value (88.7%.

  13. Effect of chemical stabilizers on the thermostability and infectivity of a representative panel of freeze dried viruses.

    Directory of Open Access Journals (Sweden)

    Boris Pastorino

    Full Text Available As a partner of the European Virus Archive (EVA FP7 project, our laboratory maintains a large collection of freeze-dried viruses. The distribution of these viruses to academic researchers, public health organizations and industry is one major aim of the EVA consortium. It is known that lyophilization requires appropriate stabilizers to prevent inactivation of the virus. However, few studies have investigated the influence of different stabilizers and lyophilization protocols on the thermostability of different viruses. In order to identify optimal lyophilization conditions that will deliver maximum retention of viral infectivity titre, different stabilizer formulations containing trehalose, sorbitol, sucrose or foetal bovine serum were evaluated for their efficacy in stabilizing a representative panel of freeze dried viruses at different storage temperatures (-20°C, +4°C and +20°C for one week, the two latter mimicking suboptimal shipping conditions. The Tissue Culture Infectious Dose 50% (TCID50 assay was used to compare the titres of infectious virus. The results obtained using four relevant and model viruses (enveloped/non enveloped RNA/DNA viruses still serve to improve the freeze drying conditions needed for the development and the distribution of a large virus collection.

  14. Microencapsulation of Purified Amylase Enzyme from Pitaya (Hylocereus polyrhizus Peel in Arabic Gum-Chitosan using Freeze Drying

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2014-03-01

    Full Text Available Amylase is one of the most important enzymes in the world due to its wide application in various industries and biotechnological processes. In this study, amylase enzyme from Hylocereus polyrhizus was encapsulated for the first time in an Arabic gum-chitosan matrix using freeze drying. The encapsulated amylase retained complete biocatalytic activity and exhibited a shift in the optimum temperature and considerable increase in the pH and temperature stabilities compared to the free enzyme. Encapsulation of the enzyme protected the activity in the presence of ionic and non-ionic surfactants and oxidizing agents (H2O2 and enhanced the shelf life. The storage stability of amylase is found to markedly increase after immobilization and the freeze dried amylase exhibited maximum encapsulation efficiency value (96.2% after the encapsulation process. Therefore, the present study demonstrated that the encapsulation of the enzyme in a coating agent using freeze drying is an efficient method to keep the enzyme active and stable until required in industry.

  15. Controlled ice nucleation using freeze-dried Pseudomonas syringae encapsulated in alginate beads.

    Science.gov (United States)

    Weng, Lindong; Tessier, Shannon N; Swei, Anisa; Stott, Shannon L; Toner, Mehmet

    2017-04-01

    The control of ice nucleation is of fundamental significance in many process technologies related to food and pharmaceutical science and cryobiology. Mechanical perturbation, electromagnetic fields and ice-nucleating agents (INAs) have been known to induce ice nucleation in a controlled manner. But these ice-nucleating methods may suffer from cumbersome manual operations, safety concerns of external fields, and biocompatibility and recovery issues of INA particles, especially when used in living systems. Given the automatic ice-seeding nature of INAs, a promising solution to overcome some of the above limitations is to engineer a biocomposite that accommodates the INA particles but minimizes their interactions with biologics, as well as enabling the recovery of used particles. In this study, freeze-dried Pseudomonas syringae, a model ice-nucleating agent, was encapsulated into microliter-sized alginate beads. We evaluated the performance of the bacterial hydrogel beads to initiate ice nucleation in water and aqueous glycerol solution by investigating factors including the size and number of the beads and the local concentration of INA particles. In the aqueous sample of a fixed volume, the total mass of the INA particles (m) was found to be the governing parameter that is solely responsible for determining the ice nucleation performance of the bacterial hydrogel beads. The freezing temperature has a strong positive linear correlation with log 10 m. The findings in this study provide an effective, predictable approach to control ice nucleation, which can improve the outcome and standardization of many ice-assisted process technologies. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. [Optimization of trehalose loading in red blood cells before freeze-drying].

    Science.gov (United States)

    Zhuang, Yuan; Liu, Jing-Han; Ouyang, Xi-Lin; Chen, Lin-Feng; Che, Ji

    2007-04-01

    The key points for better protection of trehalose in freeze-drying red blood cells (RBCs) are to resolve non-osmosis of trehalose to red blood cells and to make cytoplasmic trehalose to reach effective concentration. This study was aimed to investigate the regularity of loading RBCs with trehalose, screen out optimal loading condition and evaluate the effect of trehalose on physico-chemical parameters of RBCs during the period of loading. The cytoplasmic trehalose concentration in red blood cells, free hemoglobin and ATP level were determined at different incubation temperatures (4, 22 and 37 degrees C), different trehaolse concentrations (0, 200, 400, 600, 800 and 1000 mmol/L) and different incubation times (2, 4, 6, 8 and 10 hours), the cytoplasmic trehalose, free hemoglobin (FHb), hemoglobin (Hb) and mean corpuscular volume (MCV) in fresh RBCs and RBCs stored for 72 hours at 4 degrees C were compared, when loading condition was ensured. The results showed that with increase of incubation temperature, time and extracellular trehalose concentration, the loading of trehalose in RBCs also increased. Under the optimal loading condition, cytoplasmic trehalose concentration and free hemoglobin level of fresh RBCs and RBCs stored for 72 hours at 4 degrees C were 65.505 +/- 6.314 mmol/L, 66.2 +/- 5.002 mmol/L and 6.567 +/- 2.568 g/L, 16.168 +/- 3.922 g/L respectively. It is concluded that the most optimal condition of loading trehalose is that fresh RBCs incubate in 800 mmol/L trehalose solution for 8 hours at 37 degrees C. This condition can result in a efficient cytoplasmic trehalose concentration. The study provides an important basis for long-term preservation of RBCs.

  17. Sterilization of freeze dried manila clam (Ruditapea philippinarum) porridge for immuno-compromised patients

    Energy Technology Data Exchange (ETDEWEB)

    Song, Beom Seok; Park, Jae Nam [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2017-02-15

    This study was conducted to evaluate the combined effect of gamma irradiation and different conditions (vacuum packaging, antioxidant and freezing) on the microbiological and sensory characteristics of freeze dried Manila clam porridge (MCP) for immuno-compromised patient food. McP can be sterilized at 1 kGy to 10 kGy. the initial counts of total aerobic bacteria and yeast molds in the non-irradiated MCP were 2.4±0.5 and 1.2±0.3 log CFU g{sup -}'1, respectively, but gamma irradiation significantly decreased the total aerobic bacteria to below the detection limit (1 log CFU g{sup -1}) (5 kGy). Moreover, gamma irradiation effectively eliminated yeasts/molds at dose below than 1 kGy. However, gamma irradiation accelerated the increase of lipid oxidation and therefore, decreased the sensory characteristics of MCP as irradiation dose increased. to improve the sensory qualities of gamma irradiated MCP, combination treatment (vacuum packaging, 0.1% vitamin c) were applied. there was no significant difference in the overall acceptance scores between the combined-treatment sample (5.6 points) and the non-irradiated samples (6.0). the results indicate that combination treatment (vacuum packaging, 0.1% vitamin c) may help to maintain the quality of MCP. therefore, it considered that irradiation of MCP with combined treatment and this is an effective method for the consumption as a special purpose food such as for space travel or immuno-compromised patients.

  18. The effects of freeze-dried Ganoderma lucidum mycelia on a recurrent oral ulceration rat model.

    Science.gov (United States)

    Xie, Ling; Zhong, Xiaohong; Liu, Dongbo; Liu, Lin; Xia, Zhilan

    2017-12-01

    Conventional scientific studies had supported the use of polysaccharides and β-glucans from a number of fungi, including Ganoderma lucidum for the treatment of recurrent oral ulceration (ROU). Our aim of the present study was to evaluate whether freeze-dried powder from G. lucidum mycelia (FDPGLM) prevents ROU in rats. A Sprague-Dawley (SD) rat model with ROU was established by autoantigen injection. The ROU rats were treated with three different dosages of FDPGLM and prednisone acetate (PA), and their effects were evaluated according to the clinical therapeutic evaluation indices of ROU. High-dose FDPGLM induced significantly prolonged total intervals and a reduction in the number of ulcers and ulcer areas, thereby indicating that the treatment was effective in preventing ROU. Enzyme-linked immunosorbent assay (ELISA) showed that high-dose FDPGLM significantly enhanced the serum transforming growth factor-β1 (TGF-β1) levels, whereas reduced those of interleukin-6 (IL-6) and interleukin-17 (IL-17). Flow cytometry (FCM) showed that the proportion of CD4 + CD25 + Foxp3 + (forkhead box P3) regulatory T cells (Tregs) significantly increased by 1.5-fold in the high-dose FDPGLM group compared to that in the rat model group (P < 0.01). The application of middle- and high-dose FDPGLM also resulted in the upregulation of Foxp3 and downregulation of retinoid-related orphan receptor gamma t(RORγt) mRNA. High-dose FDPGLM possibly plays a role in ROU by promoting CD4 + CD25 + Foxp3 + Treg and inhibiting T helper cell 17 differentiation. This study also shows that FDPGLM may be potentially used as a complementary and alternative medicine treatment scheme for ROU.

  19. Retention of metabolized antimony, cobalt, iodine, mercury, selenium and zinc in various tissues of the rat following freeze-drying and oven-drying at different temperatures

    International Nuclear Information System (INIS)

    Iyengar, G.V.; Kasperek, K.; Feinendegen, L.E.

    1977-01-01

    Loss of Sb, Co, I, Hg, Se, and Zn during freeze-drying and oven-drying at 80 0 C, 105 0 C, and 120 0 C were studied in rat tissues that contained metabolized radioactive isotopes. No loss was observed for any of the 6 elements on freeze-drying. However, tissue-specific differences were observed in many cases for the elements Hg, Se, I, and Sb on oven-drying. Although the losses were statistically significant, they remained in most cases between 2 and 10%, with the exception of Hg at 120 0 C, where the losses in some of the tissues were unpredictable. With respect to urine, freeze-drying and oven-drying at 80 0 C were found to be relatively safe for the elements Hg and I. At 105 0 C and above, serious loss of Hg was observed. For Se only freeze-drying was found to be safe

  20. Clinical and Histomorphometric Assessment of Lateral Alveolar Ridge Augmentation Using a Corticocancellous Freeze-Dried Allograft Bone Block.

    Science.gov (United States)

    Ahmadi, Roya Shariatmadar; Sayar, Ferena; Rakhshan, Vahid; Iranpour, Babak; Jahanbani, Jahanfar; Toumaj, Ahmad; Akhoondi, Nasrin

    2017-06-01

    Horizontal ridge augmentation with allografts has attracted notable attention because of its proper success rate and the lack of disadvantages of autografts. Corticocancellous block allografts have not been adequately studied in humans. Therefore, this study clinically and histomorphometrically evaluated the increase in ridge width after horizontal ridge augmentation using corticocancellous block allografts as well as implant success after 12 to 18 months after implantation. In 10 patients receiving implants (3 women, 7 men; mean age = 45 years), defective maxillary alveolar ridges were horizontally augmented using freeze-dried bone allograft blocks. Ridge widths were measured before augmentation, immediately after augmentation, and ∼6 months later in the reentry surgery for implantation. This was done at points 2 mm (A) and 5 mm (B) apically to the crest. Biopsy cores were acquired from the implantation site. Implant success was assessed 15.1 ± 2.7 months after implantation (range = 12-18 months). Data were analyzed using Friedman and Dunn tests (α = 0.05). At point A, ridge widths were 2.77 ± 0.37, 8.02 ± 0.87, and 6.40 ± 0.66 mm, respectively, before surgery, immediately after surgery, and before implantation. At point B, ridge widths were 3.40 ± 0.39, 9.35 ± 1.16, and 7.40 ± 1.10 mm, respectively, before surgery, immediately after surgery, and before implantation. The Friedman test showed significant increases in ridge widths, both at point A and point B (both P = .0000). Postaugmentation resorption was about 1.5-2 mm and was statistically significant at points A and B (P < .05, Dunn). The percentage of newly formed bone, residual graft material, and soft tissue were 33.0% ± 11.35% (95% confidence interval [CI] = 24.88%-41.12%), 37.50% ± 19.04% (95% CI = 23.88%-51.12%), and 29.5%, respectively. The inflammation was limited to grades 1 or zero. Twelve to 18 months after implantation, no implants caused pain or showed exudates or pockets. Radiographic

  1. Raman microscopy of freeze-dried mouse eyeball-slice in conjunction with the "in vivo cryotechnique".

    Science.gov (United States)

    Terada, Nobuo; Ohno, Nobuhiko; Saitoh, Sei; Fujii, Yasuhisa; Ohguro, Hiroshi; Ohno, Shinichi

    2007-07-01

    The wavelength of Raman-scattered light depends on the molecular composition of the substance. This is the first attempt to acquire Raman spectra of a mouse eyeball removed from a living mouse, in which the eyeball was preserved using the "in vivo cryotechnique" followed by freeze-drying. Eyeballs were cryofixed using a rapid freezing cryotechnique, and then sliced in the cryostat machine. The slices were sandwiched between glass slides, freeze-dried, and analyzed with confocal Raman microscopy. Important areas including various eyeball tissue layers were selected using bright-field microscopy, and then the Raman spectra were obtained at 240 locations. Four typical patterns of Raman spectra were electronically mapped on the specimen images obtained by the bright-field microscopy. Tissue organization was confirmed by embedding the same eyeball slice used for Raman spectra into epoxy resin and the thick sections were prepared with the inverted capsule method. Each Raman spectral pattern represents a different histological layer in the eyeball which was mapped by comparing the images of toluidine blue staining and Raman mapping with different colors. In the choroid and pigment cell layer, the Raman spectrum had two peaks, corresponding to melanin. Some of the peaks of the Raman spectra obtained from the blood vessels in sclera and the photoreceptor layer were similar to those obtained from the purified hemoglobin and rhodopsin proteins, respectively. Our experimental protocol can distinguish different tissue components with Raman microscopy; therefore, this method can be very useful for examining the distribution of a biological structures and/or chemical components in rapidly frozen freeze-dried tissue.

  2. Fabrication and electrical characterization of 15% yttrium-doped barium zirconate-nitrate freeze drying method combined with vacuum heating

    International Nuclear Information System (INIS)

    Imashuku, Susumu; Uda, Tetsuya; Nose, Yoshitaro; Awakura, Yasuhiro

    2011-01-01

    Research highlights: → Very fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from powder mixed by the nitrate freeze-drying method. → Large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained using the synthesized powder. → Grain boundary resistance was not inversely proportional to the grain size as theoretically expected. → Specific grain boundary conductivity varies with samples because impurities and/or evaporation loss of barium oxide might affect the grain-boundary resistance in 15% yttrium-doped barium zirconate. - Abstract: We applied a nitrate freeze-drying method to obtain a fine synthesized powder of 15% yttrium-doped barium zirconate. Fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from a powder mixed by the nitrate freeze-drying method. However, we could not obtain such fine powder by synthesizing in air. Using the powder synthesized in vacuum, large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained after sintering. Then, the bulk and grain boundary resistance were evaluated by AC 2-terminal measurement of sample in the form of bar and pellet and DC 4-terminal measurement of bar-shape sample. The grain boundary resistance was not inversely proportional to the grain size as theoretically expected. We concluded that specific grain boundary conductivity varies with samples. Some impurities, evaporation loss of barium oxide and/or other unexpected reasons might affect the grain boundary resistance in 15% yttrium-doped barium zirconate.

  3. Management of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow.

    Science.gov (United States)

    Datta, N K; Das, K P; Alam, M S; Kaiser, M S

    2014-07-01

    Unicameral bone cyst is a common benign bone tumor and most frequent cause of the pathological fracture in children. We have started a prospective study for that treatment of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnated with autogenous bone marrow in the department of Orthopaedics, Bangabandhu Sheikh Mujib Medical University (BSMMU) during May 1999 to April 2012. Aim of this study was to see Freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow a satisfactory graft material in the treatment of unicameral bone cyst as well as factors such as patients age, sex, cyst size and site of lesion influence on cyst healing. A total 35 patients of unicameral bone cyst were operated. In this study out of 35 patients, male were 22(62.86%) and female were 13(37.14). Male Female ratio 22:13(1.70:1) Age of the patients ranging from 2 years 6 month to 20 years, mean age 12.18 years more common 11 years to 20 years 29(82.86%) patients. Common bones sites involvements are proximal end of Humerus 20(57.14%), proximal end of Femur 7(20 %), proximal end of Tibia 3(8.57%), Calcanium 2(5.71%), proximal end of Ulna 1(2.86%), shaft of Radius 1(2.86%) and Phalanx 1(2.86%). Final clinical outcome of unicameral bone cyst treated by thorough curettage of cavity and tightly filled with freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow in which healed (success rate) 88.57% (31) and recurrence rate is 11.43% (4). P value is unicameral bone cyst.

  4. Effects of Freeze-dried Mulberry on Antioxidant Activities and Fermented Characteristics of Yogurt during Refrigerated Storage

    OpenAIRE

    Sung, Jung-Min; Kim, Young-Boong; Kum, Jun-Seok; Choi, Yun-Sang; Seo, Dong-Ho; Choi, Hyun-Wook; Park, Jong-Dae

    2015-01-01

    This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h....

  5. Optimization of a pharmaceutical freeze-dried product and its process using an experimental design approach and innovative process analyzers.

    Science.gov (United States)

    De Beer, T R M; Wiggenhorn, M; Hawe, A; Kasper, J C; Almeida, A; Quinten, T; Friess, W; Winter, G; Vervaet, C; Remon, J P

    2011-02-15

    The aim of the present study was to examine the possibilities/advantages of using recently introduced in-line spectroscopic process analyzers (Raman, NIR and plasma emission spectroscopy), within well-designed experiments, for the optimization of a pharmaceutical formulation and its freeze-drying process. The formulation under investigation was a mannitol (crystalline bulking agent)-sucrose (lyo- and cryoprotector) excipient system. The effects of two formulation variables (mannitol/sucrose ratio and amount of NaCl) and three process variables (freezing rate, annealing temperature and secondary drying temperature) upon several critical process and product responses (onset and duration of ice crystallization, onset and duration of mannitol crystallization, duration of primary drying, residual moisture content and amount of mannitol hemi-hydrate in end product) were examined using a design of experiments (DOE) methodology. A 2-level fractional factorial design (2(5-1)=16 experiments+3 center points=19 experiments) was employed. All experiments were monitored in-line using Raman, NIR and plasma emission spectroscopy, which supply continuous process and product information during freeze-drying. Off-line X-ray powder diffraction analysis and Karl-Fisher titration were performed to determine the morphology and residual moisture content of the end product, respectively. In first instance, the results showed that - besides the previous described findings in De Beer et al., Anal. Chem. 81 (2009) 7639-7649 - Raman and NIR spectroscopy are able to monitor the product behavior throughout the complete annealing step during freeze-drying. The DOE approach allowed predicting the optimum combination of process and formulation parameters leading to the desired responses. Applying a mannitol/sucrose ratio of 4, without adding NaCl and processing the formulation without an annealing step, using a freezing rate of 0.9°C/min and a secondary drying temperature of 40°C resulted in

  6. Developing a framework to model the primary drying step of a continuous freeze-drying process based on infrared radiation

    DEFF Research Database (Denmark)

    Van Bockstal, Pieter-Jan; Corver, Jos; Mortier, Séverine Thérèse F.C.

    2018-01-01

    . These results assist in the selection of proper materials which could serve as IR window in the continuous freeze-drying prototype. The modelling framework presented in this paper fits the model-based design approach used for the development of this prototype and shows the potential benefits of this design...... requires the fundamental mechanistic modelling of each individual process step. Therefore, a framework is presented for the modelling and control of the continuous primary drying step based on non-contact IR radiation. The IR radiation emitted by the radiator filaments passes through various materials...

  7. Viability of L. casei during fermentation in soymilk and freeze-dried soymilk; effect of cryoprotectant, rehydration and storage temperature

    Directory of Open Access Journals (Sweden)

    Kristina Mladenovska

    2005-12-01

    Full Text Available The aim of the work was to investigate the behaviour of L. casei and the effect of sorbitol on its viability during fermentation in soymilk drink. Values for pH, ranging from 6.82 to 3.42 in the soymilk drink without sorbitol and from 6.74 to 3.41 in the drink with sorbitol were noted during 72 h of fermentation at 25oC. The corresponding values for titratable acidity ranged from 0.071% to 0.758% and from 0.073% to 0.761%, respectively. Soymilk was found to support the growth of L. casei with improvement in viability for 0.24 log at the end of fermentation when sorbitol was added. Survival of L. casei and the effectiveness of sorbitol in improving viability during freeze-drying, subsequent rehydration and during a 5-week period of storage under different temperatures were also investigated. After freeze-drying, L. casei exhibited a survival percent of approximately 46%. Sorbitol improved the viability of L. casei by 0.51 log immediately after freeze-drying and by 1.30 log and 0.47 log during five weeks of storage at 25oC and 4oC, respectively. Further study revealed that the freeze-dried fermented soymilk rehydrated at 45oC was optimum for the recovery of L. casei with improvement in recovery for 0.68 log when sorbitol was added. A higher percent of survival was noted when the dried soymilk was stored at 4oC than at 25oC with improved viability at the end of 5 weeks storage for approximately 6 log for drinks with and without sorbitol. Fermented dried soymilk with sorbitol afforded significant tolerance of L. casei to acid stress. Generally, a stable probiotic diary product was prepared in which the concentration of L. casei remained above therapeutic level of 107 cfu/ml.

  8. Preparation of therapeutic dose of 177Lu-DOTA-TATE using a novel single vial freeze-dried kit: a comparison with 'in-situ' preparation at hospital radiopharmacy.

    Science.gov (United States)

    Das, Tapas; Banerjee, Sharmila; Shinto, Ajit; Kamaleshwaran, K K; Sarma, H D

    2014-01-01

    Patient dose of (177)Lu-DOTA-TATE, used for providing radiotherapeutic treatment to the patients suffering from cancers of neuroendocrine origin, could be prepared at the hospital radiopharmacy either 'in-situ' or by using freezedried kits. The objective of the present work is to formulate and evaluate a single vial freeze-dried DOTA-TATE kit, which is capable of producing up to 7.4 GBq (200 mCi) dose of (177)Lu-DOTA-TATE and to compare the two methodologies presently used for the preparation of the agent. Freeze-dried DOTA-TATE kits, comprising a lyophilized mixture of DOTA-TATE, gentisic acid and ammonium acetate, were prepared and used for the formulation of patient doses of (177)Lu-DOTA-TATE. The kits were subjected to detailed radiochemical evaluation and the shelf-life of the kits was determined. The pharmacokinetic behavior of the agent was studied in normal Wistar rats. These kits were utilized for treating the patients suffering from various types of neuroendocrine cancers. The freeze-dried kits were used for the preparation of up to 7.4 GBq (200 mCi) therapeutic doses of (177)Lu- DOTA-TATE with a radiochemical purity of >99% and were found to have sufficiently long shelf-life. Biological studies carried out in normal Wistar rats exhibited no significant accumulation of activity in any of the vital organs/tissue except in kidneys and non-accumulated activity showed major renal clearance. Clinical studies carried out in cancer patients exhibited accumulation of activity in the cancerous lesions and metastatic sites. The kit was useful for the convenient preparation of therapeutic dose of (177)Lu-DOTA-TATE, suitable for human administration. The use of kit is expected to reduce the batch failure and radiation exposure to the working personnel.

  9. Vial freeze-drying, part 1: new insights into heat transfer characteristics of tubing and molded vials.

    Science.gov (United States)

    Hibler, Susanne; Wagner, Christophe; Gieseler, Henning

    2012-03-01

    In order to optimize a freeze-drying cycle, information regarding the heat transfer characteristics of the container system is imperative. Two most recently developed tubing (TopLyo™) and molded (EasyLyo™) vial designs were compared with a standard serum tubing and molded vial, a polymer vial (TopPac™), and an amber molded EasyLyo™. In addition, the impact of methodology on the determination of reliable vial heat transfer coefficient (K(v) ) data is examined in detail. All K(v) s were gravimetrically determined by sublimation tests with pure water at 50, 100, 200, and 400 mTorr. In contrast to the traditional assumption that molded vials exhibit inefficient heat transfer characteristics, these vials showed a very similar performance compared with their serum tubing counterparts in the relevant pressure range for freeze-drying. At 100 mTorr, the TopLyo™ center vials show only 4% higher K(v) values than the EasyLyo™ center vials. All glass vials outmatch the polymer vial in terms of heat transfer, up to 30% elevated heat transfer for the TopLyo™ center vials at 400 mTorr. Sublimation tests have demonstrated to be a valuable tool to investigate the heat transfer characteristics of vials, but results are dependent on methodology. New developments in molded vial manufacturing lead to improved heat transfer performance. Copyright © 2011 Wiley Periodicals, Inc.

  10. Microencapsulation by freeze-drying of potassium norbixinate and curcumin with maltodextrin: stability, solubility, and food application.

    Science.gov (United States)

    Sousdaleff, Mirian; Baesso, Mauro Luciano; Medina Neto, Antonio; Nogueira, Ana Cláudia; Marcolino, Vanessa Aparecida; Matioli, Graciette

    2013-01-30

    Stability of potassium norbixinate and curcumin by microencapsulation with maltodextrin DE20 and freeze-drying was evaluated as a function of exposition to light, air, different pH, water solubility, and in food applications. The best results were obtained with microencapsulated potassium norbixinate 1:20, which, when vacuum-packed and in the presence of natural light, showed color retention of 78%, while microencapsulated curcumin 1:20 showed color retention of 71%. Differential scanning calorimetry and thermogravimetry provided an indication of interaction between colorants and maltodextrin. Photoacoustic spectroscopy (PAS) showed that free and microencapsulated colorants exhibited high rates of absorption throughout the measured spectral region. This work evidenced that the freeze-drying process is favorable for microencapsulation of curcumin by maltodextrin, providing improved solubility to the microencapsulated colorant. Both microencapsulated colorants showed relevant results for use in a wide range of pH and food applications. The PAS technique was useful for the evaluation of the stability of free and microencapsulated colorants.

  11. Application of the Quality by Design Approach to the Freezing Step of Freeze-Drying: Building the Design Space.

    Science.gov (United States)

    Arsiccio, Andrea; Pisano, Roberto

    2018-06-01

    The present work shows a rational method for the development of the freezing step of a freeze-drying cycle. The current approach to the selection of freezing conditions is still empirical and nonsystematic, thus resulting in poor robustness of control strategy. The final aim of this work is to fill this gap, describing a rational procedure, based on mathematical modeling, for properly choosing the freezing conditions. Mechanistic models are used for the prediction of temperature profiles during freezing and dimension of ice crystals being formed. Mathematical description of the drying phase of freeze-drying is also coupled with the results obtained by freezing models, thus providing a comprehensive characterization of the lyophilization process. In this framework, deep understanding of the phenomena involved is required, and according to the Quality by Design approach, this knowledge can be used to build the design space. The step-by-step procedure for building the design space for freezing is thus described, and examples of applications are provided. The calculated design space is validated upon experimental data, and we show that it allows easy control of the freezing process and fast selection of appropriate operating conditions. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Changes of hydrogen peroxide and radical-scavenging activity of raspberry during osmotic, convective, and freeze-drying.

    Science.gov (United States)

    Novaković, Miroslav M; Stevanović, Snežana M; Gorjanović, Stanislava Ž; Jovanovic, Predrag M; Tešević, Vele V; Janković, Miodrag A; Sužnjević, Desanka Ž

    2011-05-01

    This study was conducted to investigate the influence of different drying treatments on antioxidant (AO) activity and phenolic content of raspberry (Rubus idaeus), cultivar Willamette. Whole raspberry fruits were dried convectively (air-drying), osmotically, and freeze-dried. Acetone-water extracts of fresh and dried raspberries were assessed for total phenolic content by standard Folin-Ciocalteau method. Two AO assays were applied, a recently developed direct current (DC) polarographic assay based on decrease of anodic oxidation current of hydrogen peroxide and widely used radical scavenge against the 1,1-diphenyl-2-picrylhydrazyl (DPPH). Strong correlation has been obtained between both AO assays and total phenolic content. In addition, some individual phenolic compounds present in raspberry have been assessed using DPPH and DC polarographic assay. Comparison and evaluation of drying methods has been based on preservation of AO activity and total phenolic content. Obtained results confirmed superiority of freeze-drying; convective drying caused slight changes while osmotic dehydration showed a significant decrease of phenolic compounds and AO activity. © 2011 Institute of Food Technologists®

  13. Effect of amino acids on the stability of spray freeze-dried immunoglobulin G in sugar-based matrices.

    Science.gov (United States)

    Emami, Fakhrossadat; Vatanara, Alireza; Najafabadi, Abdolhosein Rouholamini; Kim, Yejin; Park, Eun Ji; Sardari, Soroush; Na, Dong Hee

    2018-07-01

    The purpose of this study was to prepare spray freeze-dried particles of immunoglobulin G (IgG) using various combinations of trehalose and different amino acids (leucine, phenylalanine, arginine, cysteine, and glycine), and investigate the effect of the amino acids on the stability of IgG during the spray freeze-drying (SFD) process and storage. The morphology and structural integrity of the processed particles were evaluated by physical and spectroscopic techniques. SFD-processed IgG without any excipient resulted in the formation of aggregates corresponding to approximately 14% of IgG. In contrast, IgG formulations stabilized using an optimal level of leucine, phenylalanine, or glycine in the presence of trehalose displayed aggregates <2.2%. In particular, phenylalanine combined with trehalose was most effective in stabilizing IgG against shear, freezing, and dehydration stresses during SFD. Arginine and cysteine were destabilizers displaying aggregation and fragmentation of IgG, respectively. Aggregation and fragmentation were evaluated by dynamic light scattering, ultraviolet spectrophotometry, size-exclusion chromatography, and microchip capillary gel electrophoresis. The IgG formulations prepared with leucine, phenylalanine, or glycine in the presence of trehalose showed good stability after storage at 40 °C and 75% relative humidity for 2 months. Thus, a combination of the excipients trehalose and uncharged, nonpolar amino acids appears effective for production of stable SFD IgG formulations. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Solubility enhancement of BCS Class II drug by solid phospholipid dispersions: Spray drying versus freeze-drying.

    Science.gov (United States)

    Fong, Sophia Yui Kau; Ibisogly, Asiye; Bauer-Brandl, Annette

    2015-12-30

    The poor aqueous solubility of BCS Class II drugs represents a major challenge for oral dosage form development. Using celecoxib (CXB) as model drug, the current study adopted a novel solid phospholipid nanoparticle (SPLN) approach and compared the effect of two commonly used industrial manufacturing methods, spray- and freeze-drying, on the solubility and dissolution enhancement of CXB. CXB was formulated with Phospholipoid E80 (PL) and trehalose at different CXB:PL:trehalose ratios, of which 1:10:16 was the optimal formulation. Spherical amorphous SPLNs with average diameters <1μm were produced by spray-drying; while amorphous 'matrix'-like structures of solid PL dispersion with larger particle sizes were prepared by freeze-drying. Formulations from both methods significantly enhanced the dissolution rates, apparent solubility, and molecularly dissolved concentration of CXB in phosphate buffer (PBS, pH 6.5) and in biorelevant fasted state simulated intestinal fluid (FaSSIF, pH 6.5) (p<0.05). While similar dissolution rates were found, the spray-dried SPLNs had a larger enhancement in apparent solubility (29- to 132-fold) as well as molecular solubility (18-fold) of CXB at equilibrium (p<0.05). The strong capability of the spray-dried SPLNs to attain 'true' supersaturation state makes them a promising approach for bioavailability enhancement of poorly soluble drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Quality by design in formulation and process development for a freeze-dried, small molecule parenteral product: a case study.

    Science.gov (United States)

    Mockus, Linas N; Paul, Timothy W; Pease, Nathan A; Harper, Nancy J; Basu, Prabir K; Oslos, Elizabeth A; Sacha, Gregory A; Kuu, Wei Y; Hardwick, Lisa M; Karty, Jacquelyn J; Pikal, Michael J; Hee, Eun; Khan, Mansoor A; Nail, Steven L

    2011-01-01

    A case study has been developed to illustrate one way of incorporating a Quality by Design approach into formulation and process development for a small molecule, freeze-dried parenteral product. Sodium ethacrynate was chosen as the model compound. Principal degradation products of sodium ethacrynate result from hydrolysis of the unsaturated ketone in aqueous solution, and dimer formation from a Diels-Alder condensation in the freeze-dried solid state. When the drug crystallizes in a frozen solution, the eutectic melting temperature is above -5°C. Crystallization in the frozen system is affected by pH in the range of pH 6-8 and buffer concentration in the range of 5-50 mM, where higher pH and lower buffer concentration favor crystallization. Physical state of the drug is critical to solid state stability, given the relative instability of amorphous drug. Stability was shown to vary considerably over the ranges of pH and buffer concentration examined, and vial-to-vial variability in degree of crystallinity is a potential concern. The formulation design space was constructed in terms of pH and drug concentration, and assuming a constant 5 mM concentration of buffer. The process design space is constructed to take into account limitations on the process imposed by the product and by equipment capability.

  16. Enhanced dissolution and oral bioavailability of valsartan solid dispersions prepared by a freeze-drying technique using hydrophilic polymers.

    Science.gov (United States)

    Xu, Wei-Juan; Xie, Hong-Juan; Cao, Qing-Ri; Shi, Li-Li; Cao, Yue; Zhu, Xiao-Yin; Cui, Jing-Hao

    2016-01-01

    This study aimed to improve the dissolution rate and oral bioavailability of valsartan (VAL), a poorly soluble drug using solid dispersions (SDs). The SDs were prepared by a freeze-drying technique with polyethylene glycol 6000 (PEG6000) and hydroxypropylmethylcellulose (HPMC 100KV) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant without using any organic solvents. In vitro dissolution rate and physicochemical properties of the SDs were characterized using the USP paddle method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and Fourier transform-infrared (FT-IR) spectroscopy, respectively. In addition, the oral bioavailability of SDs in rats was evaluated by using VAL (pure drug) as a reference. The dissolution rates of the SDs were significantly improved at pH 1.2 and pH 6.8 compared to those of the pure drug. The results from DSC, XRD showed that VAL was molecularly dispersed in the SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between VAL and its carriers. The SDs exhibited significantly higher values of AUC 0-24 h and Cmax in comparison with the pure drug. In conclusion, hydrophilic polymer-based SDs prepared by a freeze-drying technique can be a promising method to enhance dissolution rate and oral bioavailability of VAL.

  17. Effect of physical properties on the stability of Lactobacillus bulgaricus in a freeze-dried galacto-oligosaccharides matrix.

    Science.gov (United States)

    Tymczyszyn, E Elizabeth; Sosa, Natalia; Gerbino, Esteban; Hugo, Ayelen; Gómez-Zavaglia, Andrea; Schebor, Carolina

    2012-04-16

    The ability of galacto-oligosaccharides (GOS) to protect Lactobacillus delbrueckii subsp. bulgaricus upon freeze drying was analyzed on the basis of their capacity to form glassy structures. Glass transition temperatures (T(g)) of a GOS matrix at various relative humidities (RH) were determined by DSC. Survival of L. bulgaricus in a glassy GOS matrix was investigated after freezing, freeze drying, equilibration at different RHs and storage at different temperatures. At 32 °C, a drastic viability loss was observed. At 20 °C, the survival was affected by the water content, having the samples stored at lower RHs, the highest survival percentages. At 4°C, no decay in the cells count was observed after 45 days of storage. The correlation between molecular mobility [as measured by Proton nuclear magnetic resonance (¹H NMR)] and loss of viability explained the efficiency of GOS as cryoprotectants. The preservation of microorganisms was improved at low molecular mobility and this condition was obtained at low water contents and low storage temperatures. These results are important in the developing of new functional foods containing pre and probiotics. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Beef, chicken and lamb fatty acid analysis--a simplified direct bimethylation procedure using freeze-dried material.

    Science.gov (United States)

    Lee, M R F; Tweed, J K S; Kim, E J; Scollan, N D

    2012-12-01

    When fractionation of meat lipids is not required, procedures such as saponification can be used to extract total fatty acids, reducing reliance on toxic organic compounds. However, saponification of muscle fatty acids is laborious, and requires extended heating times, and a second methylation step to convert the extracted fatty acids to fatty acid methyl esters prior to gas chromatography. Therefore the development of a more rapid direct methylation procedure would be of merit. The use of freeze-dried material for analysis is common and allows for greater homogenisation of the sample. The present study investigated the potential of using freeze-dried muscle samples and a direct bimethylation to analyse total fatty acids of meat (beef, chicken and lamb) in comparison with a saponification procedure followed by bimethylation. Both methods compared favourably for all major fatty acids measured. There was a minor difference in relation to the C18:1 trans 10 isomer with a greater (Psaponification. However, numerically the difference was small and likely as a result of approaching the limits of isomer identification by single column gas chromatography. Differences (Psaponification to analyse total fatty acids from muscle samples. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Novel Budesonide Particles for Dry Powder Inhalation Prepared Using a Microfluidic Reactor Coupled With Ultrasonic Spray Freeze Drying.

    Science.gov (United States)

    Saboti, Denis; Maver, Uroš; Chan, Hak-Kim; Planinšek, Odon

    2017-07-01

    Budesonide (BDS) is a potent active pharmaceutical ingredient, often administered using respiratory devices such as metered dose inhalers, nebulizers, and dry powder inhalers. Inhalable drug particles are conventionally produced by crystallization followed by milling. This approach tends to generate partially amorphous materials that require post-processing to improve the formulations' stability. Other methods involve homogenization or precipitation and often require the use of stabilizers, mostly surfactants. The purpose of this study was therefore to develop a novel method for preparation of fine BDS particles using a microfluidic reactor coupled with ultrasonic spray freeze drying, and hence avoiding the need of additional homogenization or stabilizer use. A T-junction microfluidic reactor was employed to produce particle suspension (using an ethanol-water, methanol-water, and an acetone-water system), which was directly fed into an ultrasonic atomization probe, followed by direct feeding to liquid nitrogen. Freeze drying was the final preparation step. The result was fine crystalline BDS powders which, when blended with lactose and dispersed in an Aerolizer at 100 L/min, generated fine particle fraction in the range 47.6% ± 2.8% to 54.9% ± 1.8%, thus exhibiting a good aerosol performance. Subsequent sample analysis confirmed the suitability of the developed method to produce inhalable drug particles without additional homogenization or stabilizers. The developed method provides a viable solution for particle isolation in microfluidics in general. Copyright © 2017 American Pharmacists Association®. All rights reserved.

  20. Freeze-drying for sustainable synthesis of nitrogen doped porous carbon cryogel with enhanced supercapacitor and lithium ion storage performance

    International Nuclear Information System (INIS)

    Ling, Zheng; Yu, Chang; Fan, Xiaoming; Liu, Shaohong; Yang, Juan; Zhang, Mengdi; Wang, Gang; Xiao, Nan; Qiu, Jieshan

    2015-01-01

    A chitosan (CS) based nitrogen doped carbon cryogel with a high specific surface area (SSA) has been directly synthesized via a combined process of freeze-drying and high-temperature carbonization without adding any activation agents. The as-made carbon cryogel demonstrates an SSA up to 1025 m 2 g −1 and a high nitrogen content of 5.98 wt%, while its counterpart derived from CS powder only shows an SSA of 26 m 2 g −1 . Freeze-drying is a determining factor for the formation of carbon cryogel with a high SSA, where the CS powder with a size of ca. 200 μm is transformed into the sheet-shaped cryogel with a thickness of 5–8 μm. The as-made carbon cryogel keeps the sheet-shaped structure and the abundant pores are formed in situ and decorated inside the sheets during carbonization. The carbon cryogel shows significantly enhanced performance as supercapacitor and lithium ion battery electrodes in terms of capacity and rate capability due to its quasi two-dimensional (2D) structure with reduced thickness. The proposed method may provide a simple approach to configure 2D biomass-derived advanced carbon materials for energy storage devices. (paper)

  1. Dielectric properties of a BaTiO3 ceramic prepared by using the freeze drying method

    International Nuclear Information System (INIS)

    Al-Shakarchi, Emad K.

    2010-01-01

    A modified catecholate process has been developed to synthesize high-purity barium titanate by using a freeze drying method to produce ultra-fine powders from a barium titanium catechol complex, Ba[Ti(C 6 H 4 O 2 ) 3 ]. The complex prepared from TiCl 4 , C 6 H 4 (OH) 2 and BaCO 3 . The freeze drying of the complex Ba[Ti(C 6 H 4 O 2 ) 3 ] under a primary vacuum at a freezing temperature of -50 .deg. C for a long time 24 hrs is necessary to transfer the complex Ba[Ti(C 6 H 4 O 2 ) 3 ] from a liquid phase to a solid phase. A subsequent calcination of the complex for 12 hrs at a temperature of 700 .deg. C was very important to remove the acetates from the mixture. Finally, a sintering process was required for the pellets so that high density samples could be investigated. The dielectric properties, the structural phase, and the particle size of the sintered pellets have investigated as functions of frequency and temperature in order to determine the critical temperature for the phase transition. X-ray diffraction was used to investigate the structural properties and the particle size. The tetragonal phase of BaTiO 3 with the lattice constants a = b = 3.9734 A, and c = 4.012 A was successfully obtained.

  2. Determination of the dried product resistance variability and its influence on the product temperature in pharmaceutical freeze-drying.

    Science.gov (United States)

    Scutellà, Bernadette; Trelea, Ioan Cristian; Bourlès, Erwan; Fonseca, Fernanda; Passot, Stephanie

    2018-07-01

    During the primary drying step of the freeze-drying process, mass transfer resistance strongly affects the product temperature, and consequently the final product quality. The main objective of this study was to evaluate the variability of the mass transfer resistance resulting from the dried product layer (R p ) in a manufacturing batch of vials, and its potential effect on the product temperature, from data obtained in a pilot scale freeze-dryer. Sublimation experiments were run at -25 °C and 10 Pa using two different freezing protocols: with spontaneous or controlled ice nucleation. Five repetitions of each condition were performed. Global (pressure rise test) and local (gravimetric) methods were applied as complementary approaches to estimate R p . The global method allowed to assess variability of the evolution of R p with the dried layer thickness between different experiments whereas the local method informed about R p variability at a fixed time within the vial batch. A product temperature variability of approximately ±4.4 °C was defined for a product dried layer thickness of 5 mm. The present approach can be used to estimate the risk of failure of the process due to mass transfer variability when designing freeze-drying cycle. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Application of fourier-transform infrared (ft-ir) spectroscopy for determination of total phenolics of freeze dried lemon juices

    International Nuclear Information System (INIS)

    Sherazi, S.T.H.; Bhutto, A.A.; Mehesar, S.A.

    2017-01-01

    A cost effective and environmentally safe analytical method for rapid assessment of total phenolic content (TPC) in freeze dried lemon juice samples was developed using transmission Fourier-transform infrared spectroscopy (FT-IR) in conjunction with chemometric techniques. Two types of calibrations i.e. simple Beer's law and partial least square (PLS) were applied to investigate most accurate calibration model based on region from1420 to 1330 cm-1. The better analytical performance was obtained by PLS technique coefficient of determination (R2), root mean square error of calibration (RMSEC) with the value of 0.999 and 0.00864, respectively. The results of TPC in freeze dried lemon juice samples obtained by transmission FT-IR were compared with TPC observed by Folin-Ciocalteu (FC) assay and found to be comparable. Outcomes of the present study indicate that transmission FT-IR spectroscopic approach could be used as an alternative approach in place of Folin-Ciocalteu (FC) assay which is expensive and time-consuming conventional chemical methods for determination of the total phenolic content of lemon fruits. (author)

  4. Optimisation of phenolic extraction from Averrhoa carambola pomace by response surface methodology and its microencapsulation by spray and freeze drying.

    Science.gov (United States)

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2015-03-15

    Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Fast freeze-drying cycle design and optimization using a PAT based on the measurement of product temperature.

    Science.gov (United States)

    Bosca, Serena; Barresi, Antonello A; Fissore, Davide

    2013-10-01

    This paper is focused on the use of an innovative Process Analytical Technology for the fast design and optimization of freeze-drying cycles for pharmaceuticals. The tool is based on a soft-sensor, a device that uses the experimental measure of product temperature during freeze-drying, a mathematical model of the process, and the Extended Kalman Filter algorithm to estimate the sublimation flux, the residual amount of ice in the vial, and some model parameters (heat and mass transfer coefficients). The accuracy of the estimations provided by the soft-sensor has been shown using as test case aqueous solutions containing different excipients (sucrose, polyvinylpyrrolidone), processed at various operating conditions, pointing out that the soft-sensor allows a fast estimation of model parameters and product dynamics without involving expensive hardware or time consuming analysis. The possibility of using the soft-sensor to calculate in-line (or off-line) the design space of the primary drying phase is here presented and discussed. Results evidences that by this way, it is possible to identify the values of the heating fluid temperature that maintain product temperature below the limit value, as well as the operating conditions that maximize the sublimation flux. Various experiments have been carried out to test the effectiveness of the proposed approach for a fast design of the cycle, evidencing that drying time can be significantly reduced, without impairing product quality. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Use of a soft sensor for the fast estimation of dried cake resistance during a freeze-drying cycle.

    Science.gov (United States)

    Bosca, Serena; Barresi, Antonello A; Fissore, Davide

    2013-07-15

    This paper deals with the determination of dried cake resistance in a freeze-drying process using the Smart Soft Sensor, a process analytical technology recently proposed by the authors to monitor the primary drying stage of a freeze-drying process. This sensor uses the measurement of product temperature, a mathematical model of the process, and the Kalman filter algorithm to estimate the residual amount of ice in the vial as a function of time, as well as the coefficient of heat transfer between the shelf and the product and the resistance of the dried cake to vapor flow. It does not require expensive (additional) hardware in a freeze-dryer, provided that thermocouples are available. At first, the effect of the insertion of the thermocouple in a vial on the structure of the product is investigated by means of experimental tests, comparing both sublimation rate and cake structure in vials with and without thermocouple. This is required to assess that the temperature measured by the thermocouple is the same of the product in the non-monitored vials, at least in a non-GMP environment, or when controlled nucleation methods are used. Then, results about cake resistance obtained in an extended experimental campaign with aqueous solutions containing different excipients (sucrose, mannitol and polyvinylpyrrolidone), processed in various operating conditions, are presented, with the goal to point out the accuracy of the proposed methodology. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Role of mono- and oligosaccharides from FOS as stabilizing agents during freeze-drying and storage of Lactobacillus delbrueckii subsp. bulgaricus.

    Science.gov (United States)

    Romano, Nelson; Schebor, Carolina; Mobili, Pablo; Gómez-Zavaglia, Andrea

    2016-12-01

    The aim of this work was to assess the role of mono- and oligosaccharides present in fructo-oligosaccharides (FOS) mixtures as protective agents during freeze-drying and storage of Lactobacillus delbrueckii subsp. bulgaricus CIDCA 333. Different FOS mixtures were enzymatically obtained from sucrose and further purified by removing the monosaccharides produced as secondary products. Their glass transition temperatures (T g ) were determined at 11, 22 and 33% relative humidity (RH). Bacterial cultures were freeze-dried in the presence of 20% w/v solutions of the studied FOS. Their protective effect during freeze-drying was assessed by bacterial plate counting, and by determining the lag time from growth kinetics and the uptake of propidium iodide (PI). Plate counting during bacterial storage at 4°C, and 11, 22 and 33% RH for 80days completed this rational analysis of the protective effect of FOS. Purification of FOS led to an increase of T g in all the conditions assayed. Microorganisms freeze-dried in the presence of non-purified FOS were those with the shortest lag times. Bacteria freeze-dried with pure or commercial FOS (92% of total FOS) showed larger lag times (8.9-12.6h). The cultivability of microorganisms freeze-dried with non-purified FOS and with sucrose was not significantly different from that of bacteria before freeze-drying (8.74±0.14logCFU/mL). Pure or commercial FOS were less efficient in protecting bacteria during freeze-drying. All the protectants prevented membrane damage. The cultivability of bacteria freeze-dried with FOS decayed <1logarithmicunit after 80days of storage at 11% RH. When storing at 22 and 33% RH, pure and commercial FOS were those that best protected bacteria, and FOS containing monosaccharides were less efficient. The effect of FOS on bacterial protection is the result of a balance between monosaccharides, sucrose and larger FOS in the mixtures: the smallest sugars are more efficient in protecting lipid membranes, and the

  8. Headspace Moisture Mapping and the Information That Can Be Gained about Freeze-Dried Materials and Processes.

    Science.gov (United States)

    Cook, Isobel A; Ward, Kevin R

    2011-01-01

    Regulatory authorities require proof that lyophilization (freeze drying) cycles have been developed logically and demonstrate uniformity. One measure of uniformity can be consistency of residual water content throughout a batch. In primary drying, heat transfer is effected by gaseous convection and conduction as well as the degree of shelf contact and evenness of heat applied; therefore residual water can be affected by container location, degree of container/tray/shelf contact, radiative heating, packing density, product formulation, and the cycle conditions themselves. In this study we have used frequency modulation spectroscopy (FMS) to create a map of headspace moisture (HSM) for 100% of vials within a number of freeze-dried batches. Karl Fischer (KF)/HSM correlations were investigated in parallel with the moisture mapping studies. A clear, linear relationship was observed between HSM and KF values for vials containing freeze-dried sucrose, implying a relatively straightforward interaction between water and the lyophilized cake for this material. Mannitol demonstrated a more complex correlation, with the interaction of different crystalline forms giving important information on the uniformity of the material produced. It was observed that annealing had a significant impact on the importance of heat transfer by conduction for vials in direct and non-direct contact with the shelf. Moisture mapping of all vials within the freeze dryer enabled further information to be obtained on the relationship of the formulation, process conditions, and equipment geometry on the intra-batch variability in HSM level. The ability of FMS to allow 100% inspection could mean that this method could play an important part in process validation and quality assurance. Lyophilization, also known as freeze drying, is a relatively old technique that has been used in its most basic form for thousands of years (e.g., preservation of fish and meat products). In its more advanced form it is

  9. Radiosterilization process control in plants using electron accelerators

    International Nuclear Information System (INIS)

    Stuglik, Z.

    1997-01-01

    Electron beam parameters deciding the irradiation dose in radiosterilization plants should be continuously controlled during the process. Dosimetric procedure suitable to irradiated material and dose range should be chosen. The practical advice and directions in this subject have been done. 7 refs

  10. Microbiological problems in radiosterilization; Zagadnienia mikrobiologiczne w sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Czerniawski, E [Lodz Univ. (Poland)

    1997-10-01

    Microbiological problems connected with radiosterilization of medical materials, pharmaceuticals and cosmetics have been discussed in detail. Dose-response relationship for different bacteria has been shown. Recommended sterilization and postirradiation control procedures have been described. 24 refs, 6 figs, 5 tabs.

  11. Characterization and in vitro evaluation of freeze-dried microparticles composed of granisetron-cyclodextrin complex and carboxymethylcellulose for intranasal delivery.

    Science.gov (United States)

    Cho, Hyun-Jong; Balakrishnan, Prabagar; Shim, Won-Sik; Chung, Suk-Jae; Shim, Chang-Koo; Kim, Dae-Duk

    2010-11-15

    The aim of this study was to prepare microparticles (MPs) of granisetron (GRN) in combination with hydroxypropyl-β-cyclodextrin (HP-β-CD) and sodium carboxymethylcellulose (CMC-Na) by the simple freeze-drying method for intranasal delivery. The composition of MPs was determined from the phase-solubility study of GRN in various CDs. Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis and differential scanning calorimetry (DSC) studies were performed to evaluate possible interactions between GRN and excipients. The results indicated the formation of inclusion complex between GRN and CD, and the conversion of drug into amorphous state. The in vitro release of GRN from MPs was determined in phosphate buffered saline (pH 6.4) at 37°C. Cytotoxicity of the MPs and in vitro permeation study were conducted by using primary human nasal epithelial (HNE) cells and their monolayer system cultured by air-liquid interface (ALI) method, respectively. The MPs showed significantly higher GRN release profile compared to pure GRN. Moreover, the prepared MPs showed significantly lower cytotoxicity and higher permeation profile than that of GRN powder (p<0.05). These results suggested that the MPs composed of GRN, HP-β-CD and CMC-Na represent a simple and new GRN intranasal delivery system as an alternative to the oral and intravenous administration of GRN. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

    Science.gov (United States)

    Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

    2016-11-01

    Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite-collagen composite) -alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union-related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone.

  13. Safety assessment of freeze-dried powdered Tenebrio molitor larvae (yellow mealworm) as novel food source: Evaluation of 90-day toxicity in Sprague-Dawley rats.

    Science.gov (United States)

    Han, So-Ri; Lee, Byoung-Seok; Jung, Kyung-Jin; Yu, Hee-Jin; Yun, Eun-Young; Hwang, Jae Sam; Moon, Kyoung-Sik

    2016-06-01

    Worldwide demand for novel food source has grown and edible insects are a promising food sources for humans. Tenebrio molitor, as known as yellow mealworm, has advantages of being rich in protein, and easy to raise as a novel food source. The objective of this study was to evaluate subchronic toxicity, including potential hypersensitivity, of freeze-dried powdered T. molitor larvae (fdTML) in male and female Sprague-Dawley rats. The fdTML was administered orally once daily at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 90 days. A toxicological assessment was performed, which included mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings, histopathologic examination and allergic reaction. There were no fdTML- related findings in clinical signs, urinalysis, hematology and serum chemistry, gross examination, histopathologic examination or allergic reaction. In conclusion, the No Observed Adverse Effect Level (NOAEL) for fdTML was determined to be in excess of 3000 mg/kg/day in both sexes of rats under the experimental conditions of this study. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Encapsulation of antioxidant phenolic compounds extracted from spent coffee grounds by freeze-drying and spray-drying using different coating materials

    DEFF Research Database (Denmark)

    Ballesteros, Lina F.; Ramirez, Monica J.; Orrego, Carlos E.

    2017-01-01

    Freeze-drying and spray-drying techniques were evaluated for encapsulation of phenolic compounds (PC) extracted from spent coffee grounds. Additionally, the use of maltodextrin, 29 gum arabic and a mixture of these components (ratio 1:1) as wall material to retain the PC and preserve their antiox......Freeze-drying and spray-drying techniques were evaluated for encapsulation of phenolic compounds (PC) extracted from spent coffee grounds. Additionally, the use of maltodextrin, 29 gum arabic and a mixture of these components (ratio 1:1) as wall material to retain the PC and preserve...... the technique and the coating material greatly influenced the encapsulation of antioxidant PC. The best results were achieved when PC were encapsulated by freeze-drying using maltodextrin as wall material. Under these conditions, the amount of PC and FLA retained in the encapsulated sample corresponded to 62...

  15. Rapid formation of the 110 K phase in Bi-Pb-Sr-Ca-Cu-O through freeze-drying powder processing

    International Nuclear Information System (INIS)

    Song, K.H.; Liu, H.K.; Dou, S.X.; Sorrell, C.C.

    1990-01-01

    This paper reports three techniques for processing Bi-Pb-Sr-Ca-Cu-O (BPSCCO) powders investigated: dry-mixing, sol-gel formation, and freeze-drying. It was found that sintering for 120 h at 850 degrees C is required to form nearly single-phase (Bi,Pb) 2 Sr 2 Ca 2 Cu 3 O 10-y by dry-mixing, whereas sintering for 30 h at 840 degrees C was sufficient to form the 110 K (2223) phase when freeze-drying was used. The sol-gel route was found to be intermediate in efficiency between these two techniques. Freeze-drying provided highly reactive, intimately mixed, and carbon-free precursors. The presence of carbonates in the uncalcined powders was the major cause of phase segregation and sluggishness of the 110 K phase formation

  16. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process

    DEFF Research Database (Denmark)

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka

    2013-01-01

    Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate...... the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near......-dried formulations an increase in protein concentration resulted in a shift from ß-mannitol to a-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying...

  17. Effect of acid whey and freeze-dried cranberries on lipid oxidation and fatty acid composition of nitrite-/nitrate-free fermented sausage made from deer meat

    Directory of Open Access Journals (Sweden)

    Małgorzata Karwowska

    2017-01-01

    Full Text Available Objective This study evaluated the effect of acid whey and freeze-dried cranberries on the physicochemical characteristics, lipid oxidation and fatty acid composition of nitrite-free fermented sausage made from deer meat and pork fat. Antioxidant interactions between acid whey and cranberry compounds were also explored. Methods Four formulations of fermented venison sausage were prepared: F1 (control, F2 (with 5% liquid acid whey, F3 (with 0.06% of freeze-dried cranberries, and F4 (with 5% liquid acid whey and 0.06% of freeze-dried cranberries. Each sample was analyzed for pH, water activity (aw, heme iron content, 2-thiobarbituric acid reactive substances (TBARS value and conjugated dienes at the end of the manufacturing process and at 30 and 90 days of refrigerated storage. Fatty acid composition was measured once at the end of the manufacturing process. Results At the end of ripening, all samples presented statistically different values for a pH range of 4.47 to pH 4.59. The sum of the unsaturated fatty acids was higher, while the conjugated diene and the TBARS values were lower in sausages with freeze-dried cranberries as compared to the control sausage. The highest content of heme iron (21.52 mg/kg at day 90 was found in the sausage formulation with the addition of freeze-dried cranberries, which suggests that the addition of cranberries stabilized the porphyrin ring of the heme molecule during storage and thereby reduced the release of iron. The use of liquid acid whey in combination with cranberries appears to not be justified in view of the oxidative stability of the obtained products. Conclusion The results suggest that the application of freeze-dried cranberries can lower the intensity of oxidative changes during the storage of nitrite-free fermented sausage made from deer meat.

  18. The performance of five fruit-derived and freeze-dried potentially probiotic Lactobacillus strains in apple, orange and grape juices.

    Science.gov (United States)

    Garcia, Estefânia Fernandes; de Oliveira Araújo, Amanda; Luciano, Winnie Alencar; de Albuquerque, Thatyane Mariano Rodrigues; de Oliveira Arcanjo, Narciza Maria; Madruga, Marta Suely; Dos Santos Lima, Marcos; Magnani, Marciane; Saarela, Maria; de Souza, Evandro Leite

    2018-03-30

    This study assessed the survival of the fruit-derived and freeze-dried L. plantarum 49, L. brevis 59, L. paracasei 108, L. fermentum 111 and L. pentosus 129 strains during frozen storage and when incorporated into apple, orange and grape juice stored under refrigeration. Physicochemical parameters of juices containing the freeze-dried Lactobacillus strains and the survival of the test strains in the fruit juices during in vitro digestion were also evaluated. No decreases in survival rates (log N/log N0) of the freeze-dried cells were observed up to 1 month of storage. The survival rates of the freeze-dried strains L. plantarum 49 and L. paracasei 108 were >0.75 up to 4 months of storage. All freeze-dried strains exhibited survival rates of >0.75 up to 2 weeks of storage in apple juice; only L. plantarum 49 and L. paracasei 108 showed similar survival rates in orange and grape juices up to 2 weeks of storage. The contents of the monitored organic acids or sugars during storage varied depending on the added strain and the type of fruit juice. At the end of the in vitro digestion, L. brevis 59, L. paracasei 108 and L. fermentum 111 showed survival rates of >0.80 in apple juice. Apple juice was as the best substrate to the survival of the tested freeze-dried Lactobacillus strains over time. L. paracasei 108 and L. plantarum 49 as the strains presenting the best performance for incorporation in potentially probiotic fruit juices. This article is protected by copyright. All rights reserved.

  19. Fabrication of highly porous keratin sponges by freeze-drying in the presence of calcium alginate beads

    International Nuclear Information System (INIS)

    Hamasaki, Shinichi; Tachibana, Akira; Tada, Daisuke; Yamauchi, Kiyoshi; Tanabe, Toshizumi

    2008-01-01

    Novel fabrication method of highly porous and flexible keratin sponges was developed by combining a particulate-leaching method and a freeze-drying method. Reduced keratin aqueous solution was mixed with dried calcium alginate beads and was lyophilized to give keratin/calcium alginate complex, which was subsequently treated with EDTA solution to leach out calcium alginate beads. The resultant keratin sponge was flexible enough to handle even in dried state because of its quite high porosity (98.9 ± 0.1%), which was brought about by the large and small pores formed by the elimination of calcium alginate beads and water. The sponge supported the attachment and the proliferation of mouse fibroblast cells. Thus, the keratin sponge given by the present fabrication method afforded one alternative as a cell scaffold for tissue engineering

  20. Research Article: Effects of long-term simulated Martian conditions on a freeze-dried and homogenized bacterial permafrost community

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Jensen, Lars Liengård; Kristoffersen, Tommy

    2009-01-01

    Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation......, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead......, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core...

  1. Freeze drying synthesis of LiNi0.5Mn0.5O2 cathode materials

    International Nuclear Information System (INIS)

    Shlyakhtin, O.A.; Yoon, Young Soo; Choi, Sun Hee; Oh, Young-Jei

    2004-01-01

    The influence of several processing conditions on the phase formation and electrochemical performance of LiNi 0.5 Mn 0.5 O 2 powders, obtained by freeze drying method, is studied. Thermal processing in pellets at maximum heating rate promotes better crystallographic ordering of hexagonal LiNi 0.5 Mn 0.5 O 2 and maximum capacity values irrespectively of chemical composition of the precursor. Instead, intense mechanical processing of precursors exerts considerable negative effect on the electrochemical performance. Cathode materials containing superstoichiometric amount of lithium (Li 1.3 Mn 0.5 Ni 0.5 O 2+δ ) demonstrate reversible capacity values up to 190 mAh/g between 2.5 and 4.6 V

  2. Socket preservation using freeze-dried bone allograft with and without plasma rich in growth factors in dogs

    Science.gov (United States)

    Samandari, Mohammad Hasan; Haghighat, Abbas; Torabinia, Nakisa; Taghian, Mehdi; Sadri, Leyli; Naemy, Vahid

    2016-01-01

    Background: Plasma rich in growth factors (PRGF) and freeze-dried bone allograft (FDBA) are shown to promote bone healing. This study was aimed to histologically and histomorphometrically investigate the effect of combined use of PRGF and FDBA on bone formation, and compare it to FDBA alone and control group. Materials and Methods: The distal roots of the lower premolars were extracted bilaterally in four female dogs. Sockets were randomly divided into FDBA + PRGF, FDBA, and control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 4 weeks. Sockets were assessed histologically and histomorphometrically. Data were analyzed by Kruskal–Wallis test followed by Mann–Whitney U-tests utilizing the SPSS software version 20. P PRGF groups was not significant in middle and apical portions. Conclusion: The superiority of PRGF+FDBA overFDBA in socket preservation cannot be concluded from this experiment. PMID:27857769

  3. Process Analytical Technology in Freeze-Drying: Detection of the Secondary Solute + Water Crystallization with Heat Flux Sensors.

    Science.gov (United States)

    Wang, Qiming; Shalaev, Evgenyi

    2018-04-01

    In situ and non-invasive detection of solute crystallization during freeze-drying would facilitate cycle optimization and scale-up from the laboratory to commercial manufacturing scale. The objective of the study is to evaluate heat flux sensor (HFS) as a tool for monitoring solute crystallization and other first-order phase transitions (e.g., onset of freezing). HFS is a thin-film differential thermopile, which acts as a transducer to generate an electrical signal proportional to the total heat applied to its surface. In this study, HFS is used to detect both primary (ice formation) and secondary (also known as eutectic) solute + water crystallization during cooling and heating of solutions in a freeze-dryer. Binary water-solute mixtures with typical excipients concentrations (e.g., 0.9% of NaCl and 5% mannitol) and fill volumes (1 to 3 ml/vial) are studied. Secondary crystallization is detected by the HFS during cooling in all experiments with NaCl solutions, whereas timing of mannitol crystallization depends on the cooling conditions. In particular, mannitol crystallization takes place during cooling, if the cooling rate is lower than the critical value. On the other hand, if the cooling rate exceeds the critical cooling rate, mannitol crystallization during cooling is prevented, and crystallization occurs during subsequent warming or annealing. It is also observed that, while controlled ice nucleation allows initiation of the primary freezing event in different vials simultaneously, there is a noticeable vial-to-vial difference in the timing of secondary crystallization. The HFS could be a valuable process monitoring tool for non-invasive detection of various crystallization events during freeze-drying manufacturing.

  4. Preparation of freeze dried kit of sodium citrate labeled with Tc-99m used as a new kidney functional agent

    International Nuclear Information System (INIS)

    Merzah, K. S.; Abdulkrim, H. M.; Resen, H. M.; Badi, J. M.

    2012-12-01

    A new freeze-dried kit of sodium citrate complex has been prepared, to be labeled with technetium-99m can be used for diagnosis of kidney function. The labeling conditions of Tc-99m citrate complex using stannous chloride as a reducing agent for pertechnetate have been described. The GCS method reveals that the labeling efficiency of Tc-99m citrate complex is promoted by raisinng the pH of the preparation to (pH=4) using 1 N NaOH. The optimal amounts of the reactants in the preparation to obtain labeled and stable complex with high kidney uptake were found to be not less than (1 mg) sodium citrate and not more than (100μg) SnCI 2 2HO. The results show that high labeling yield (≥95%) for the labeled complex (Tc-99 Sn- citrate) can be perform due to the suitable reactant materials. The data of biodistribution experiments in the laboratory animals (Mice), clear high radioactivity accumulation labeled complex in kidney at 5 minutes post injection. The results of the radiochemical purity and biodistribution studies of the lyophilized kit approved that it was stable for about more than seven moths under normal conditions (2-8 o C ). The results of biodistribution of labeled kit have shown a good biological behavior with low radioactivity accumulation in the non-target organs (blood, liver and other organs). the aim of this study was to evaluate the potential of Tc-99-citrate complex as a new kidney functional agents and the efficiency of the freeze dried kit in the diagnosis of kidney function. (Author)

  5. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Vavpetič, P., E-mail: primoz.vavpetic@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, K. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Jeromel, L. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potočnik, N. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); FOM-Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Pongrac, P. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Department of Plant Physiology, University of Bayreuth, Universitätstr. 30, 95447 Bayreuth (Germany); Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm{sup 2} and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  6. Rational design of an influenza subunit vaccine powder with sugar glass technology : preventing conformational changes of haemagglutinin during freezing and freeze-drying

    NARCIS (Netherlands)

    Amorij, J-P; Meulenaar, J; Hinrichs, W L J; Stegmann, T; Huckriede, A; Coenen, F; Frijlink, H W

    2007-01-01

    The development of a stable influenza subunit vaccine in the dry state was investigated. The influence of various carbohydrates, buffer types and freezing rates on the integrity of haemagglutinin after freeze-thawing or freeze-drying was investigated with a range of analytical and immunological

  7. Effects of protectant and rehydration conditions on the survival rate and malolactic fermentation efficiency of freeze-dried Lactobacillus plantarum JH287.

    Science.gov (United States)

    Lee, Sae-Byuk; Kim, Dong-Hwan; Park, Heui-Dong

    2016-09-01

    In this study, Lactobacillus plantarum JH287 was used as a malolactic fermentation starter in Campbell Early wine production. L. plantarum JH287 was first lyophilized, and the malolactic fermentation potential of freeze-dried L. plantarum JH287 was investigated. Different protective media and rehydration conditions were tested to improve the survival rate of freeze-dried L. plantarum JH287. Optimal protective medium contained 10 % sorbitol and 10 % skim milk. The optimal rehydration condition was a 1-h rehydration time conducted in the same protective media, and the combination of these two methods produced a survival rate of 86.37 %. In addition, a 77.71 % survival rate was achieved using freeze-dried samples that were stored at 4 °C for 2 months. Freeze-dried L. plantarum JH287 and Saccharomyces cerevisiae Fermivin were used to inoculate the Campbell Early grape must to decrease its malic acid content. Using this mixed-fermentation method, wine showed a decrease in malic acid content after 9 days of fermentation. GC-MS analysis detected 15 volatile ester compounds in the wine. A sensory evaluation showed that the taste and aroma of mix-fermented wine were better than those of the control that had not been inoculated with L. plantarum JH287.

  8. Global Sensitivity Analysis as Good Modelling Practices tool for the identification of the most influential process parameters of the primary drying step during freeze-drying

    DEFF Research Database (Denmark)

    Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F.C.; Corver, Jos

    2018-01-01

    Pharmaceutical batch freeze-drying is commonly used to improve the stability of biological therapeutics. The primary drying step is regulated by the dynamic settings of the adaptable process variables, shelf temperature Ts and chamber pressure Pc. Mechanistic modelling of the primary drying step...

  9. Influence of different sugar cryoprotectants on the stability and physico-chemical characteristics of freeze-dried 5-fluorouracil plurilamellar vesicles

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmoud Nounou

    2005-07-01

    Full Text Available Lyophilization increases the shelf-life of liposomes by preserving it in a dry form as lyophilized cake to be reconstituted with water immediately prior to administration. Aiming at increasing stability and availability of 5-Fluorouracil liposomal products, 5-Fluorouacil Stable Plurilamellar Vesicles were prepared. Freeze dried liposomal dispersions were prepared with or without cryoprotectants. The cryoprotectants used were glucose, mannitol or trehalose in 1, 2 and 4 grams per gram phospholipids. The results showed that lyophilized cake of liposomes without cryoprotectants was compact and difficult to reconstitute, in comparison with fluffy cakes which reconstituted easily and quickly when using cryoprotectants. The percentage of 5-Fluorouracil retained in liposomes freeze-dried without cryoprotectants was 18.29% ± 0.96% and the percentage of 5-Fluorouracil retained in stable plurilamellar vesicles was 31.22% ± 0.62% using 4 grams trehalose as cryoprotectant per gram of lipid. Physico-chemical and release stability studies showed superior potentials of the lyophilized product after reconstitution in comparison to dispersion product. It may be concluded that all tested sugars have cryoprotectant effects that stabilized liposomes in the freeze dried state, where trehalose offered the most superior cryoprotectant effect for freeze dried 5-fluorouracil liposomes.

  10. Reversed phase HPLC analysis of stability and microstructural effects on degradation kinetics of β-carotene encapsulated in freeze-dried maltodextrin-emulsion systems.

    Science.gov (United States)

    Harnkarnsujarit, Nathdanai; Charoenrein, Sanguansri; Roos, Yrjö H

    2012-09-26

    Degradation of dispersed lipophilic compounds in hydrophilic solids depends upon matrix stability and lipid physicochemical properties. This study investigated effects of solid microstructure and size of lipid droplets on the stability of dispersed β-carotene in freeze-dried systems. Emulsions of β-carotene in sunflower oil were dispersed in maltodextrin systems (M040/DE6, M100/DE11, and M250/DE25.5) (8% w/w oil) and prefrozen at various freezing conditions prior to freeze-drying to control nucleation and subsequent pore size and structural collapse of freeze-dried solids. The particle size, physical state, and β-carotene contents of freeze-dried emulsions were measured during storage at various water activity (a(w)) using a laser particle size analyzer, differential scanning calorimeter, and high performance liquid chromatography (HPLC), respectively. The results showed that M040 stabilized emulsions in low temperature freezing exhibited lipid crystallization. Collapse of solids in storage at a(w) which plasticized systems to the rubbery state led to flow and increased the size of oil droplets. Degradation of β-carotene analyzed using a reversed-phase C(30) column followed first-order kinetics. Porosity of solids had a major effect on β-carotene stability; however, the highest stability was found in fully plasticized and collapsed solids.

  11. Quantitative risk assessment via uncertainty analysis in combination with error propagation for the determination of the dynamic Design Space of the primary drying step during freeze-drying

    DEFF Research Database (Denmark)

    Van Bockstal, Pieter Jan; Mortier, Séverine Thérèse F.C.; Corver, Jos

    2017-01-01

    of a freeze-drying process, allowing to quantitatively estimate and control the risk of cake collapse (i.e., the Risk of Failure (RoF)). The propagation of the error on the estimation of the thickness of the dried layer Ldried as function of primary drying time was included in the uncertainty analysis...

  12. On adaptive time stepping for large-scale parabolic problems: Computer simulation of heat and mass transfer in vacuum freeze-drying

    Czech Academy of Sciences Publication Activity Database

    Georgiev, K.; Kosturski, N.; Margenov, S.; Starý, Jiří

    2009-01-01

    Roč. 226, č. 2 (2009), s. 268-274 ISSN 0377-0427 Institutional research plan: CEZ:AV0Z30860518 Keywords : Vacuum freeze drying * Zeolites * Heat and mass transfer * Finite element method * MIC(0) preconditioning Subject RIV: BA - General Mathematics Impact factor: 1.292, year: 2009 http://apps.isiknowledge.com

  13. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process.

    Science.gov (United States)

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka; Yang, Mingshi

    2013-04-15

    Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near-infrared spectroscopy in combination with multivariate analysis and further, results were verified with X-ray powder diffraction. It was seen that the prevalence of the mannitol polymorphic form shifted from β-mannitol to δ-mannitol with increasing protein concentration in freeze-dried formulations. In spray-dried formulations an increase in protein concentration resulted in a shift from β-mannitol to α-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying process in itself, rather than the temperature, that leads to the observed solid state changes. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Effect of whey protein isolate and β-cyclodextrin wall systems on stability of microencapsulated vanillin by spray-freeze drying method.

    Science.gov (United States)

    Hundre, Swetank Y; Karthik, P; Anandharamakrishnan, C

    2015-05-01

    Vanillin flavour is highly volatile in nature and due to that application in food incorporation is limited; hence microencapsulation of vanillin is an ideal technique to increase its stability and functionality. In this study, vanillin was microencapsulated for the first time by non-thermal spray-freeze-drying (SFD) technique and its stability was compared with other conventional techniques such as spray drying (SD) and freeze-drying (FD). Different wall materials like β-cyclodextrin (β-cyd), whey protein isolate (WPI) and combinations of these wall materials (β-cyd + WPI) were used to encapsulate vanillin. SFD microencapsulated vanillin with WPI showed spherical shape with numerous fine pores on the surface, which in turn exhibited good rehydration ability. On the other hand, SD powder depicted spherical shape without pores and FD encapsulated powder yielded larger particle sizes with flaky structure. FTIR analysis confirmed that there was no interaction between vanillin and wall materials. Moreover, spray-freeze-dried vanillin + WPI sample exhibited better thermal stability than spray dried and freeze-dried microencapsulated samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Development of Biomimetic Hybrid Porous Scaffold of Chitosan/Polyvinyl Alcohol/Carboxymethyl Cellulose by Freeze-Dried and Salt Leached Technique.

    Science.gov (United States)

    Kanimozhi, K; Basha, S Khaleel; Kumari, V Sugantha; Kaviyarasu, K

    2018-07-01

    Freeze drying and salt leaching methods were applied to fabricate Chitosan/Poly(vinyl alcohol)/Carboxymethyl cellulose (CPCMC) biomimetic porous scaffolds for soft tissue engineering. The properties of these scaffolds were investigated and compared to those by freeze drying and salt leaching methods respectively. The salt-leached CS/PVA/CMC scaffolds were easily formed into desired shapes with a uniformly distributed and interconnected pore structure with an average pore size. The mechanical strength of the scaffolds increased with the porosity, and were easily modulated by the addition of carboxymethyl cellulose. The morphology of the porous scaffolds observed using a SEM exhibited good porosity and interconnectivity of pores. MTT assay using L929 fibroblast cells demonstrated that the cell viability of the porous scaffold was good. Scaffolds prepared by salt leached method show larger swelling capacity, and mechanical strength, potent antibacterial activity and more cell viability than freeze dried method. It is found that salt leaching method has distinguished characteristics of simple, efficient, feasible and less economic than freeze dried scaffolds.

  16. Analysis of the efficacy of Taiwanese freeze-dried neurotoxic antivenom against Naja kaouthia, Naja siamensis and Ophiophagus hannah through proteomics and animal model approaches.

    Science.gov (United States)

    Liu, Chien-Chun; You, Chen-Hsien; Wang, Po-Jung; Yu, Jau-Song; Huang, Guo-Jen; Liu, Chien-Hsin; Hsieh, Wen-Chin; Lin, Chih-Chuan

    2017-12-01

    In Southeast Asia, envenoming resulting from cobra snakebites is an important public health issue in many regions, and antivenom therapy is the standard treatment for the snakebite. Because these cobras share a close evolutionary history, the amino acid sequences of major venom components in different snakes are very similar. Therefore, either monovalent or polyvalent antivenoms may offer paraspecific protection against envenomation of humans by several different snakes. In Taiwan, a bivalent antivenom-freeze-dried neurotoxic antivenom (FNAV)-against Bungarus multicinctus and Naja atra is available. However, whether this antivenom is also capable of neutralizing the venom of other species of snakes is not known. Here, to expand the clinical application of Taiwanese FNAV, we used an animal model to evaluate the neutralizing ability of FNAV against the venoms of three common snakes in Southeast Asia, including two 'true' cobras Naja kaouthia (Thailand) and Naja siamensis (Thailand), and the king cobra Ophiophagus hannah (Indonesia). We further applied mass spectrometry (MS)-based proteomic techniques to characterize venom proteomes and identify FNAV-recognizable antigens in the venoms of these Asian snakes. Neutralization assays in a mouse model showed that FNAV effectively neutralized the lethality of N. kaouthia and N. siamensis venoms, but not O. hannah venom. MS-based venom protein identification results further revealed that FNAV strongly recognized three-finger toxin and phospholipase A2, the major protein components of N. kaouthia and N. siamensis venoms. The characterization of venom proteomes and identification of FNAV-recognizable venom antigens may help researchers to further develop more effective antivenom designed to block the toxicity of dominant toxic proteins, with the ultimate goal of achieving broadly therapeutic effects against these cobra snakebites.

  17. Standardization of Procedures for the Preparation of (177)Lu- and (90)Y-labeled DOTA-Rituximab Based on the Freeze-dried Kit Formulation.

    Science.gov (United States)

    Wojdowska, Wioletta; Karczmarczyk, Urszula; Maurin, Michal; Garnuszek, Piotr; Mikołajczak, Renata

    2015-01-01

    Rituximab when radiolabelled with (177)Lu or (90)Y has been investigated for the treatment of patients with Non-Hodgkin's Lymphoma. In this study, we optimized the preparation of antibody conjugates with chelating agent in the freeze-dried kit. It shortens procedures needed for the successful radiolabeling with lutetium-177 and yttrium-90 and assures reproducible labelling yields. Various molar ratios of Rituximab:DOTA (from 1:5 to 1:100) were used at the conjugation step and different purification method to remove unbound DOTA were investigated (size-exclusion chromatography, dialysis, ultrafiltration). The final monoclonal antibody concentration was quantified by Bradford method, and the number of DOTA molecules was determined by radiolabeling assay using (64)Cu. The specific activity of (177)Lu-DOTA-Rituximab and (90)Y-DOTA-Rituximab were optimized using various amounts of radiometal. Quality control (SE-HPLC, ITLC) and stability study were performed. An average of 4.2 ± 0.8 p-SCN-Bz-DOTA molecules could be randomly conjugated to a single molecule of Rituximab. The ultrafiltration system was the most efficient for purification and resulted in the highest recovery efficiency (77.2%). At optimized conditions the (177)Lu-DOTARituximab and (90)Y-DOTA-Rituximab were obtained with radiochemical purity >99% and specific activity ca. 600 MBq/mg. The radioimmunoconjugates were stable in human serum and 0.9% NaCl. After 72 h of incubation the radiochemical purity of (177)Lu-DOTA-Rituximab decreased to 94% but it was still more than 88% for (90)Y-DOTA-Rituximab. The radioimmunoconjugate showed stability after six months storage at 2 - 8(0)C, as a lyophilized formulation. Our study shows that Rituximab-DOTA can be efficiently radiolabeled with (177)Lu and (90)Y via p-SCN-Bn-DOTA using a freezedried kit.

  18. Evolution of the Radio-sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Reyes F, M. L.; Luna Z, D.

    2013-10-01

    The Radio-sterilized Tissues Bank (RTB) of the Instituto Nacional de Investigaciones Nucleares (ININ) was established in 1997, as national project supported by the IAEA, who provided equipment, training and expert missions. In July of 1999, the Secretaria de Salud (Mexico) granted the sanitary license to the RTB. The first radio-sterilized tissue was the amnion. Later on, the process of frozen and lyophilized pig skin was development. Both tissue types are used as biological dressings in patient with burns, ulcers or on injuries difficult to heal, the amnion is also used for the damage treatment in the ocular surface. In 2003, the ININ improved the facilities of the RTB and in August of that same year the certification of the Quality Administration System was obtained under the standard ISO 9001:2000, at the present time ISO 9001:2008. The support of the IAEA granted to Mexico was of 1997-2004 and 2009-2012, by means of regional and inter regional projects where was obtained equipment and training mainly, for personal of the ININ and other institutions. With the last project supported by the IAEA, two very important documents were generated for the tissues bank of Argentina, Brazil, Colombia, Costa Rica, Cuba, Ecuador, El Salvador, Mexico, Peru, Uruguay and Venezuela, strengthening the interaction among these countries. To offer more radio-sterilized tissues to the medical community, in June of 2007 the RTB signed and agreement with the Secretaria de Salud of the Mexico State by means of the Centro Estatal de Transplantes del Estado de Mexico, for the process of muscle-skeletal tissue, skin and amnion. At present, besides amnion and pig skin, in the RTB there is in existence powdered and chips bone; concluding the validation stage the human skin process is. As a social function of the ININ, the RTB has contributed to the health improvement of patients of more than 50 hospital institutions, mainly those that assist to patient of low resources in different cities of

  19. Effects of Freeze-dried Mulberry on Antioxidant Activities and Fermented Characteristics of Yogurt during Refrigerated Storage

    Science.gov (United States)

    2015-01-01

    This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h. The total polyphenol and anthocyanin content of FDMJ yogurt was higher than that of control due to the presence of phytochemical contents in mulberry. Moreover, antioxidant activity such as DPPH and reducing power was highest 5% FDMJ yogurt. During cold storage, pH decreased or remained constant in all yogurts with values ranging from 4.08 to 4.78 units. In sensory evaluation, the score of 1% FDMJ yogurt was ranked higher when compared with other yogurts. It is proposed that mulberry fruit juice powder can be used to improve sensory evaluation and enhance functionality of yogurt. PMID:26877641

  20. Is the Freeze Drying Method Effect on the Phase Transition Temperature ofβ/β́́ Lithium Zirconium Phosphate?

    Directory of Open Access Journals (Sweden)

    S. M. Seyedahmadian

    2014-07-01

    Full Text Available Spherical granules of the superionic conductor β/β́ LiZr2(PO43 in the range of sub 100 nm sizewere synthesizedvia freeze drying methodand fully reviewed in all aspects. Samples were characterized by the X-ray diffractometry (XRD, the Thermal analysis (TG, DSC, theFourier Transform Infra-Red Spectroscopy (FTIR and the Scanning Electron Microscopy (SEM.Their structuredepends largely on the method of synthesis, thermaltreatment, and conditions of storing samples. Degree of Crystallinity and phase purity in different annealing time were tested. The synthesize temperature does not exceed 873 K in any step of the synthesis.The low temperature phases (β with the Pbna space group and β́ with the P21/n space group were preparedat optimum condition. By the Differential Scanning Calorimetry it was shown the phase transition from β↔β́ occurred at about 567-597 K. The temperature of annealing the phosphate and calcination time is not very effective to phase transition temperature.

  1. Immunomodulatory effects of supercritical fluid CO2 extracts from freeze-dried powder of Tenebrio molitor larvae (yellow mealworm

    Directory of Open Access Journals (Sweden)

    QingFeng TANG

    2016-01-01

    Full Text Available Abstract In order to take full advantage of Tenebrio molitor larvae (yellow mealworm resources, the supercritical CO2 fluid freeze-dried powder of T. molitor larvae (fdTML extraction on the immune systems of mice was carried out. The results about the effects of supercritical CO2 fluid fdTML extraction on carbon expurgation and phagocytosis of peritoneal macrophages experiments of mice indicated that the fdTML extraction enhanced observably carbon expurgatory index, phagocytic rate and phagocytic index. The fdTML extraction could stimulate response of delayed hypersensitivity. The proliferation of ConA-induced mitogenic reponse for spleen lymphocyte was also increased. The amount of hemolytic antibody in mice serum increased compared with those of the control group mice. The half of hemolysis values in serum of treated mice increased compared to the control group. Furthermore, serum NO content in all treatment groups was higher than that of the control group whereas acid phosphatase and alkaline phosphatase activity was only significantly higher relative to the control group. Our findings suggest that supercritical CO2 fluid the fdTML extraction has potential as a health food supplement.

  2. Bulk specimen X-ray microanalysis of freeze-fractured, freeze-dried tissues in gerontological research

    International Nuclear Information System (INIS)

    Nagy, I.

    1988-01-01

    The rationale for choosing the freeze-fracture freeze-drying (FFFD) method of biological bulk specimen preparation as well as the theoretical and practical problems of this method are treated. FFFD specimens are suitable for quantitative X-ray microanalysis of biologically relevant elements. Although the spatial resolution of this analytical technique is low, the application of properly selected bulk standard crystals as well as the measurement of the intracellular water and dry mass content by means of another method developed in the same laboratory, allow us to obtain useful information about the age-dependent changes of ionic composition in the main intracellular compartments. The paper summarizes the problems with regard to specimen preparation, beam penetration and the quantitative analysis of FFFD specimens. The method has been applied so far mainly for the analysis of intranuclear and intracytoplasmic concentrations of Na, C1 and K in various types of cells and has resulted in a significant contribution to our understanding of the cellular mechanisms of aging. 84 references

  3. Freeze dried samples of volcanic gases - a new method for the determination of trace elements by NAA

    International Nuclear Information System (INIS)

    Bichler, M.; Sortino, F.

    1997-01-01

    A new routine technique for the determination of trace elements in volcanic gases by NAA is presented. For time and money saving reasons this method is applicable to samples, collected by the conventional method. This technique uses evacuated glass bottles, partly filled with NaOH solution to absorb acidic gas components and CO 2 , which is the main constituent of the incondensable gas fraction at ambient conditions. The application of NAA to samples collected by this method shows two main sources of difficulties: drying of NaOH without loosing volatile elements of interest (in particular Hg and Se) and the high activities of 24 Na after neutron irradiation. The first can be avoided by liquid irradiation, thereby limiting the irradiation time, the second excludes the determination of short and medium lived nuclides because of the high γ-background due to 24 Na. A new freeze drying technique enables the application of long irradiation times and therefore the use of long-lived activation products for analysis. The samples of volcanic gases were collected at the fumarole fields of La Fossa volcano on the island Vulcano. Southern Italy. This technique allows very sensitive determinations of trace elements in volcanic gases and adds highly valuable information to the understanding and modeling of volcanic gas sources. (orig.)

  4. Screening Quality Evaluation Factors of Freeze-Dried Peach (Prunus Persica L. Batsch Powders from Different Ripening Time Cultivars

    Directory of Open Access Journals (Sweden)

    Chun-ju Liu

    2017-01-01

    Full Text Available The quality evaluation of processed products is complex. To simplify the quality evaluation process and improve the efficiency, fourteen evaluation factors of freeze-dried powders of seventeen cultivars of peach at different ripening times were analyzed. The most important evaluation indicators and criteria were obtained by analysis of variance (ANOVA, correlation analysis (CA, principal component analysis (PCA, system cluster analysis (SCA, and analytic hierarchy process (AHP. Results showed that the peach powders had the significant differences in quality (P<0.05, and some processing factors were related with some physicochemical and nutritional factors. Five principle components were extracted by PCA and the cumulative contribution achieved was 84.46%. Through the score plot of the first two principal components, a clear differentiation among ripening times was found and three distinct groups were separated according to ripening time. Five characteristic factors were obtained as titratable acid, browning index, hemicellulose, hygroscopicity, and vitamin C by SCA. Their weights of 0.1249, 0.3007, 0.0514, 0.4916, and 0.0315 were obtained by AHP, respectively. The peach cultivars were divided into four evaluation grades by the comprehensive quality score.

  5. Influence of product thickness, chamber pressure and heating conditions on production rate of freeze-dried yoghurt

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, N.K. [G.B. Pant Univ., of Agriculture and Technology (India). Dept. of Mechanical Engineering; Arora, C.P. [Indian Inst. of Tech., New Delhi (India)

    1995-06-01

    The effects of product thickness, chamber pressure and heating conditions on product temperature profiles and production rate of freeze-dried yoghurt were investigated experimentally. Three sample thicknesses - 3.8 mm, 6.2 mm and 9.4 mm - were tested at chamber pressures of 0.01 and 0.5 mmHg. The production rate increased by decreasing product thickness in contact heating through the bottom of the frozen layer, whereas no significant change was observed in radiant heating. A reduction in chamber pressure from 0.50 to 0.01 mmHg increased the drying time in radiant heating. Maximum production rate was obtained when the thickness of dried product was 6.2 mm, when heat was transferred simultaneously through the frozen and dried layers, and the chamber pressure was at 0.01 mmHg. Use of the product tray developed in this study prevents the growth of dry layers at the contact surfaces. (Author)

  6. Determination of phospholipids extracted from Tsukamurella paurometabola C-924 after freeze-drying and during the subsequent storage [abstract

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    Coulibaly, I.

    2010-01-01

    Full Text Available The total lipids of Tsukamurella paurometabola C-924 were analyzed after freeze-drying. Seven individual lipids classes were identified namely neutral lipids (NLs, fatty acids (FAs, phospholipids (PLs, sterol ester (SEs, triglycerides (TGs, diglycerides (DGs and monoglycerides (MGs. The principal fatty acids identified in most lipid classes were palmitic (C16:0, palmitoleic (C16:1, oleic (C18:1, linoleic (C18:2, and linolenic (C18:3. PLs were the major constituents and accounted for 50-60% of the total lipids. PLs were fractionated. PLs of Tsukamurella paurometabola content phosphatidic acid (PA, phosphatidylethanolamine (PE, phosphatidylinositol (PI, phosphatidylcholine (PC, sphingomyelin (SM, lysophosphatidylcholine (LPC and phosphatidylglycerol (PG. It was observed that PG had the highest proportion at most points relative to other PLs and was the predominant component of PLs (30%-56%. Evolution of individual rate was followed during storage at 20°C and 40°C with or without lithothamne400®, respectively.

  7. Determination of orthodontic tooth movement and tissue reaction following demineralized freeze-dried bone allograft grafting intervention

    Science.gov (United States)

    Seifi, Massoud; Ghoraishian, Seyed Ahmad

    2012-01-01

    Background: Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. Materials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA) (CenoBone®) was used as the graft material. The defects were made by the extraction of 3rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM), alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. Results: There was a slight increase in OTM at grafted sites as they were compared to the control sites (Presorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (Presorption. PMID:22623939

  8. High homogeneity powder of Ti-Ba-Ca-Cu-O (2223) prepared by Freeze-Drying method

    International Nuclear Information System (INIS)

    Al-Shakarchi, Emad Kh.; Toma, Ziad A.

    1999-01-01

    Full text.Homogeneous high temerature superconductor ceramic powder of TI-Ba-Ca-Cu-O with transition temperature [Tc=123K] have been successfully prepared from the mixture of nitrate salts [TlNO 3 , Ba(NO 3 ) 2 , Ca(NO 3 ) 2 .4H 2 O and Cu(NO 3 ) 2 .3H 2 O] by using freeze-drying method. Freeze-dryer that was used in this work designed locally in our laboratory. This technique consider a better to get a fine powder of ceramic materials by depending on the procedure of frozen droplets with present of liquid nitrogen. SEM pictures showed the size of grains of about [0.8 μm]. We conclude that the high sintering temperature, for the prepared powders in this technique, for long time [120 hrs] will increase the inter diffusion between the grains ahich caused the decreasing in the density of the sample which may be given a better results than the obtained in a previous works

  9. Labeling of new formulation of tin-sucralfate freeze-dried kit with technetium-99m and its biological evaluation

    International Nuclear Information System (INIS)

    Al-Azzawi, H.M.A.K.; Abas, S.A.E.; Ahmed, S.S.; Omran, S.G.; Risen, R.H.; Al-Nuzal, S.M.D.

    2012-01-01

    The present investigation deals with a simple preparation of new formulation of tin-sucralfate freeze-dried kit (F.D.K.), to be directly labeled with 99m Tc at optimal pH value of 7.0. The lyophilized form containing 100 mg sucralfate and 11.3 mg dihydrated stannous chloride. Other optimal pH values of the preparation were found to be from 4.0 to 11.0. The range of sucralfate amount studied (50-500 mg) not affected the radiochemical purity of the labeled complex. The radiochemical purity and the stability of the labeled preparation that assessed by filtration were more than 95%. 99m Tc sucralfate was radiochemical stable up to a specific activity of 1,000 mCi per gram which was more stable than earlier published value (700 mCi per gram) without any radiolytic decomposition. The biological behavior of 99m Tc-pertechnetate was evaluated in two groups of animals, the first group (neither fasted nor ulcerated) and the second group (fasted and ulcerated mice). The data of organ distribution of 99m Tc-sucralfate in ulcerated fasted mice showed that more than 99% of the administered dose was accumulated in the stomach (87.92%) and intestine (11.43%). The radioanalytical results together with the in vivo-biological behavior of the labeled preparation demonstrate it's stability, efficacy and usefulness in medical applications for the detection of gastrointestinal ulcers. (author)

  10. ANTIOXIDANT CAPACITY OF PEQUI (Caryocar brasiliense Camb. PULP IS PRESERVED BY FREEZE-DRYING AND LIGHT-RESISTANT PACKAGING

    Directory of Open Access Journals (Sweden)

    NARA RÚBIA RODRIGUES DO NASCIMENTO

    Full Text Available ABSTRACT Pequi (Caryocar brasiliense Camb. pulp is rich in bioactive compounds. However, seasonality and perishability limit its availability in the market. This work aimed to determine the physicochemical characteristics, including phenolic compounds and carotenoid concentrations, as well as the antioxidant capacity of lyophilized pequi pulp during storage in various packaging materials for 180 days. Pequi fruits were pulped, ground, freeze-dried and then vacuum packaged in transparent polyethylene (TP, polyethylene coated by aluminum foil (PA and laminated foil (LA, respectively. The samples were stored under controlled temperature, humidity and luminosity. Proximate composition, phenolic compounds and carotenoids concentrations, and antioxidant capacity (DPPH• assay were determined at the beginning of the study and the end of each month, during 180 days. Lyophilized pequi pulp had 48.87, 6.17, and 4.20 g.100 g-1 lipids, proteins, and total dietary fiber, respectively, and 556.79 kcal.100 g-1 energy. PA and LA had similar effects against light-induced carotenoid oxidation. Negative correlations between the phenolic compound concentration and storage period, and antioxidant capacity and storage period; and a positive correlation between antioxidant capacity and phenolic compound content were observed. Light-resistant packaging decreased the carotenoid loss. Among the packaging, LA preserved the phenolic compounds and antioxidant capacity most effectively.

  11. Socket preservation using freeze-dried bone allograft with and without plasma rich in growth factors in dogs

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    Mohammad Hasan Samandari

    2016-01-01

    Full Text Available Background: Plasma rich in growth factors (PRGF and freeze-dried bone allograft (FDBA are shown to promote bone healing. This study was aimed to histologically and histomorphometrically investigate the effect of combined use of PRGF and FDBA on bone formation, and compare it to FDBA alone and control group. Materials and Methods: The distal roots of the lower premolars were extracted bilaterally in four female dogs. Sockets were randomly divided into FDBA + PRGF, FDBA, and control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 4 weeks. Sockets were assessed histologically and histomorphometrically. Data were analyzed by Kruskal-Wallis test followed by Mann-Whitney U-tests utilizing the SPSS software version 20. P < 0.05 was considered statistically significant. Results: While the difference in density of fibrous tissue in three groups was not statistically significant (P = 0.343, the bone density in grafted groups was significantly higher than the control group (P = 0.021. The least decrease in all socket dimensions was observed in the FDBA group. However, these differences were only significant in coronal portion at week 4. Regarding socket dimensions and bone density, the difference between FDBA and FDBA+PRGF groups was not significant in middle and apical portions. Conclusion: The superiority of PRGF+FDBA overFDBA in socket preservation cannot be concluded from this experiment.

  12. {sup 68}Ga Labeling of DOTMP using Freeze-dried Kit for the Imaging of Bone Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Dho, So Hee; Choi, Sangmu; Kim, Sooyong; Cho, Eunha; Lee, Soyoung; Jung, Sunghee; Lim, Jaecheong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Bone is a favorable site of metastasis and is invaded common primary tumors such as prostate, breast, and lung. Due to the progressive pain and mortality of the bone metastasis, effort has been focused on the detection of bone metastasis in the field of nuclear medicine (Mitterhauser, Toegel et al. 2007, Mirzaei, Jalilian et al. 2015). In designing suitable imaging agents for bone metastasis, multidentate polyaminophosphonate are regarded as the most promising candidates as carrier ligands owing to their high bone affinity, selective localization in skeletal lesions and ability to form metal chelates with high in-vivo stability (Chakraborty, Das et al. 2008). 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene. Freeze-dried DOTMP kit vial was consist of 400 μ of DOTMP, 19.27 mg of ammonium acetate and 17.62 mg of ascorbic acid. All the preparative steps were carried out under aseptic conditions, and the prepared kit vials were shown in Fig. 3(A). The easy and efficient labeling of this kit with 68Ga make them suitable for preparing 68Ga-DOTMP for imaging of bone metastasis.

  13. Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part II: Breads Not Containing Oil as an Ingredient

    Directory of Open Access Journals (Sweden)

    Viren Ranawana

    2016-09-01

    Full Text Available The present article describes the second part of a study investigating the effect of adding vegetables on the nutritional, physico-chemical, and oxidative properties of wheat bread, and specifically focuses on bread that does not contain oil as an added ingredient. Wheat flour breads fortified with freeze-dried carrot, tomato, beetroot or broccoli were developed and assessed for their nutritional composition, antioxidant potential, oxidative stability, and storage properties. Using a simulated in vitro model, the study also examined the impact of vegetable addition on the oxidative stability of macronutrients during gastro-intestinal digestion. Adding vegetables improved the nutritional and functional attributes of the oil-free breads. However, they demonstrated a lower antioxidant potential compared to their oil-containing counterparts. Similarly, the textural and storage properties of the oil-free vegetable breads were poorer compared to the oil-containing breads. As expected, in the absence of oil the oil-free breads were associated with lower lipid oxidation both in their fresh form and during gastro-intestinal digestion. Adding vegetables reduced protein oxidation in the fresh oil-free breads but had no effect during gastro-intestinal digestion. The impact of vegetables on macronutrient oxidation in the oil-free breads during digestion appears to be vegetable-specific with broccoli exacerbating it and the others having no effect. Of the evaluated vegetables, beetroot showed the most promising nutritional and physico-chemical benefits when incorporated into bread that does not contain added oil.

  14. The Palatability of Lopinavir and Ritonavir Delivered by an Innovative Freeze-Dried Fast-Dissolving Tablet Formulation

    Directory of Open Access Journals (Sweden)

    David W. Pittman

    2018-01-01

    Full Text Available Negative hedonic sensory qualities of HIV antiretroviral drugs often reduce patient adherence particularly in pediatric populations requiring oral consumption. This study examines the palatability of an innovative delivery mechanism utilizing a freeze-drying-in-blister approach to create fast-dissolving tablets (FDTs containing a fixed-dose combination of lopinavir and ritonavir (LPV/r. Consumption patterns of solutions during brief-access and long-term testing and baby foodstuff consumption were analyzed to evaluate the orosensory detection and avoidance of placebo FDTs containing no LPV/r (FDT− and FDTs containing LPV/r (FDT+. Rats showed no change in consumption patterns for the placebo FDT− compared with control solutions. Rats can detect but do not avoid FDT+ at body-weight-adjusted dosages in both brief-access (30-s and long-term (23 h consumption tests. There is an aversive response to concentrated doses of FDT+ during brief-access tests that cannot be masked by 25% sucrose. However, the strongest FDT+ concentration was not rejected when mixed with 50 g of applesauce, banana sauce, or rice cereal baby foodstuffs. The averseness of the FDT+ was associated with the presence of LPV/r and not the FDT− formulation itself. The novel FDT formulation appears to be a palatable delivery mechanism for oral antiretroviral pharmaceuticals especially when mixed with baby foodstuffs.

  15. Synthesis and characterization of LiFePo4/C cathode material by freeze drying method with PVP

    Directory of Open Access Journals (Sweden)

    Kuzmanović Maja D.

    2014-01-01

    Full Text Available Lithium iron phosphate is a promising cathode material for lithium ion battery application thanks to its good characteristics. Here is presented the freeze drying method for the preparation of carbon coated LiFePO4, where PVP is used as a carbon source. The main advantage of this method is mixing at the atomic level and introducing the carbon source into the precursor solution. The synthesis process can be divided into three stages: freezing of a precursor solution, drying under vacuum until water evaporates and calicination of as-dried powder at slightly reductive atmosphere. Powder X-ray diffraction measurement demonstrated single phase LiFePO4 with crystallite size of 45.8 nm. Morphology and particle size was revealed with scanning electron microscopy and particle size analyzer. Galvanostatic cycling from 2.3 to 4.1 V vs. Li/Li+, shows typical LiFePO4 redox behavior with plateau at 3.4 V. The discharge capacity value obtained at C/10 rate was 154 mAh- 1, with decrease on greater C-rates.

  16. Effects of Freeze-dried Mulberry on Antioxidant Activities and Fermented Characteristics of Yogurt during Refrigerated Storage.

    Science.gov (United States)

    Sung, Jung-Min; Kim, Young-Boong; Kum, Jun-Seok; Choi, Yun-Sang; Seo, Dong-Ho; Choi, Hyun-Wook; Park, Jong-Dae

    2015-01-01

    This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h. The total polyphenol and anthocyanin content of FDMJ yogurt was higher than that of control due to the presence of phytochemical contents in mulberry. Moreover, antioxidant activity such as DPPH and reducing power was highest 5% FDMJ yogurt. During cold storage, pH decreased or remained constant in all yogurts with values ranging from 4.08 to 4.78 units. In sensory evaluation, the score of 1% FDMJ yogurt was ranked higher when compared with other yogurts. It is proposed that mulberry fruit juice powder can be used to improve sensory evaluation and enhance functionality of yogurt.

  17. Okara: A Nutritionally Valuable By-product Able to Stabilize Lactobacillus plantarum during Freeze-drying, Spray-drying, and Storage

    Science.gov (United States)

    Quintana, Gabriel; Gerbino, Esteban; Gómez-Zavaglia, Andrea

    2017-01-01

    Okara is a nutritionally valuable by-product produced in large quantities as result of soymilk elaboration. This work proposes its use as both culture and dehydration medium during freeze-drying, spray-drying, and storage of Lactobacillus plantarum CIDCA 83114. Whole and defatted okara were employed as culture media for L. plantarum CIDCA 83114. The growth kinetics were followed by plate counting and compared with those of bacteria grown in MRS broth (control). No significant differences in plate counting were observed in the three media. The fatty acid composition of bacteria grown in whole and defatted okara showed a noticeable increase in the unsaturated/saturated (U/S) fatty acid ratio, with regard to bacteria grown in MRS. This change was mainly due to the increase in polyunsaturated fatty acids, namely C18:2. For dehydration assays, cultures in the stationary phase were neutralized and freeze-dried (with or without the addition of 250 mM sucrose) or spray-dried. Bacteria were plate counted immediately after freeze-drying or spray-drying and during storage at 4°C for 90 days. Freeze-drying in whole okara conducted to the highest bacterial recovery. Regarding storage, spray-dried bacteria previously grown in whole and defatted okara showed higher plate counts than those grown in MRS. On the contrary, freeze-dried bacteria previously grown in all the three culture media were those with the lowest plate counts. The addition of sucrose to the dehydration media improved their recovery. The higher recovery of microorganisms grown in okara after freeze-drying and spray-drying processes and during storage was ascribed to both the presence of fiber and proteins in the dehydration media, and the increase in U/S fatty acids ratio in bacterial membranes. The obtained results support for the first time the use of okara as an innovative matrix to deliver L. plantarum. Considering that okara is an agro-waste obtained in large quantities, these results represent an

  18. Radiochemical studies, pre-clinical investigation and preliminary clinical evaluation of "1"7"0Tm-EDTMP prepared using in-house freeze-dried EDTMP kit

    International Nuclear Information System (INIS)

    Das, Tapas; Shinto, Ajit; Kamaleshwaran, Koramadai K.; Sarma, Haladhar D.; Mohammed, Sahiralam Khan; Mitra, Arpit; Lad, Sangita; Rajan, M.G.R.; Banerjee, Sharmila

    2017-01-01

    The objective of the present work is to formulate "1"7"0Tm-EDTMP using an in-house freeze-dried EDTMP kit and evaluate its potential as a bone pain palliation agent. Patient dose of "1"7"0Tm-EDTMP was prepared with high radiochemical purity using the lyophilized kit at room temperature within 15 min. Pre-clinical evaluation in normal Wistar rats revealed selective skeletal accumulation with extended retention. Preliminary clinical investigation in 8 patients with disseminated skeletal metastases exhibited selective uptake in the bone and retention therein for a long duration. - Highlights: • Formulation of patient dose of "1"7"0Tm-EDTMP using freeze-dried EDTMP kit. • Radiochemical studies and pre-clinical evaluation of the agent in animal model. • Clinical evaluation in eight cancer patients with disseminated skeletal metastases.

  19. Effect of Microencapsulation by Spray-Drying and Freeze-Drying Technique on the Antioxidant Properties of Blueberry (Vaccinium myrtillus Juice Polyphenolic Compounds

    Directory of Open Access Journals (Sweden)

    Wilkowska Agnieszka

    2016-03-01

    Full Text Available Blueberry juice with high polyphenol concentration was spray- or freeze-dried using different coating materials: HP-β-cyclodextrin and β-cyclodextrin. The quality of the obtained powders was characterised by their anthocyanin content, total polyphenols and antioxidant capacity. SEM was used for monitoring structures and size (2–20 μm of the microparticles. The losses of total phenolic compounds during spray-drying reached 76–78% on average, while these of anthocyanins about 57%. Freeze-dried powders showed better retention values of anthocyanins, which was about 1.5-fold higher than for the spray-dried counterparts. All blueberry preparations studied were characterised by very high radical scavenging activity.

  20. Evaluation of shrinkage temperature of bovine pericardium tissue for bioprosthetic heart valve application by differential scanning calorimetry and freeze-drying microscopy

    Directory of Open Access Journals (Sweden)

    Virgilio Tattini Jr

    2007-03-01

    Full Text Available Bovine pericardium bioprosthesis has become a commonly accepted device for heart valve replacement. Present practice relies on the measurement of shrinkage temperature, observed as a dramatic shortening of tissue length. Several reports in the last decade have utilized differential scanning calorimetry (DSC as an alternative method to determine the shrinkage temperature, which is accompanied by the absorption of heat, giving rise to an endothermic peak over the shrinkage temperature range of biological tissues. Usually, freeze-drying microscope is used to determine collapse temperature during the lyophilization of solutions. On this experiment we used this technique to study the shrinkage event. The aim of this work was to compare the results of shrinkage temperature obtained by DSC with the results obtained by freeze-drying microscopy. The results showed that both techniques provided excellent sensitivity and reproducibility, and gave information on the thermal shrinkage transition via the thermodynamical parameters inherent of each method.

  1. ESR measurements and the detection of radiosterilization of drugs

    International Nuclear Information System (INIS)

    Gibella, M.; Crucq, A.S.; Tilquin, B.

    1993-01-01

    The ESR spectrum of trapped radicals in irradiated solid antibiotics could permit the detection of the radiosterilization. The ESR signal is detected only after radiolysis; at room temperature, this ESR spectrum is observable for a few hours or until several years. The rate of the metathesis reactions can be fast or very slow, the reaction path is unknown,. However, in many cases, the polycrystalline solid phase exhibits its ability to keep radicals for a long period of time and the detection of the radiolysis is possible during this period. 10 figs., 1 tab

  2. Role of hydroxypropyl-β-cyclodextrin on freeze-dried and gamma-irradiated PLGA and PLGA–PEG diblock copolymer nanospheres for ophthalmic flurbiprofen delivery

    Directory of Open Access Journals (Sweden)

    Vega E

    2012-03-01

    Full Text Available Estefanía Vega1, M Antònia Egea1, Ana Cristina Calpena2, Marta Espina1, M Luisa García11Department of Physical Chemistry, 2Department of Biopharmacy and Pharmaceutical Technology, Institute of Nanoscience and Nanotechnology, Faculty of Pharmacy, University of Barcelona, Barcelona, SpainAbstract: Poly(D,L-lactide-co-glycolide and poly(D,L-lactide-co-glycolide with poly(ethylene glycol nanospheres (NSs incorporating flurbiprofen (FB were freeze-dried with several cryoprotective agents and sterilized by γ-irradiation. Only when 5.0% (w/v hydroxypropyl-β-cyclodextrin (HPβCD was used, a complete resuspension by manual shaking and almost identical particle size of the NSs was obtained after freeze-drying. In vitro drug release and ex vivo corneal permeation of NSs with and without HPβCD were evaluated. The presence of HPβCD resulted in a reduction of burst effect, providing a more sustained release of the drug. A significant decrease in the FB transcorneal permeation of NSs containing HPβCD was obtained, related to the slower diffusion of FB observed in the in vitro results. The uptake mechanism of the NSs was examined by confocal microscopy, suggesting that NSs penetrate corneal epithelium through a transcellular pathway. Ocular tolerance was assessed in vitro and in vivo by the Eytex™ and Draize test, respectively. Long-term stability studies revealed that γ-irradiated NSs stored as freeze-dried powders maintained their initial characteristics. Stability studies of the resuspended NSs after 3 months of storage in the aqueous form showed that NSs were stable at 4°C, while formulations stored at 25°C and 40°C increased their initial particle size.Keywords: nanospheres, poly(D,L-lactide-co-glycolide, poly(ethylene glycol, hydroxypropyl-β-cyclodextrin, freeze-drying, γ-irradiation 

  3. Effect of molecular weight and ratio of poly ethylene glycols' derivatives in combination with trehalose on stability of freeze-dried IgG.

    Science.gov (United States)

    Mohammad Zadeh, Amir Hossein; Rouholamini Najafabadi, Abdolhosein; Vatanara, Alireza; Faghihi, Homa; Gilani, Kambiz

    2017-12-01

    The influence of poly ethylene glycol (PEG) at different molecular weights (MWs) and ratios was studied on the stability of freeze-dried immune globulin G (IgG). PEGs (600-4000 Dalton) at concentrations of 0.5 and 5% W/V were applied in the presence of 40 and 60% W/W of trehalose to prepare freeze-dried IgG formulations. Size-exclusion chromatography, infra-red spectroscopy, differential scanning calorimeter, and gel electrophoresis were performed to characterize lyophilized samples. Pure IgG demonstrated the highest aggregation of 5.77 ± 0.10% after process and 12.66 ± 0.50% as well as 44.69 ± 0.50% upon 1 and 2 months of storage at 45 °C, respectively. 5% W/V of PEGs 4000 in combination with 40% W/W trehalose, significantly suppressed aggregation, 0.05 ± 0.01%, with minimum aggregation rate constant of 0.32 (1/month). The integrity of IgG molecules and secondary conformation were properly preserved in all formulations comparing native IgG. It could be concluded that appropriate concentration and MW of PEGs, prominently augmented stabilizing effect of trehalose on freeze-dried antibody through inserting additional supportive mechanisms of actions.

  4. Robustness testing in pharmaceutical freeze-drying: inter-relation of process conditions and product quality attributes studied for a vaccine formulation.

    Science.gov (United States)

    Schneid, Stefan C; Stärtzel, Peter M; Lettner, Patrick; Gieseler, Henning

    2011-01-01

    The recent US Food and Drug Administration (FDA) legislation has introduced the evaluation of the Design Space of critical process parameters in manufacturing processes. In freeze-drying, a "formulation" is expected to be robust when minor deviations of the product temperature do not negatively affect the final product quality attributes. To evaluate "formulation" robustness by investigating the effect of elevated product temperature on product quality using a bacterial vaccine solution. The vaccine solution was characterized by freeze-dry microscopy to determine the critical formulation temperature. A conservative cycle was developed using the SMART™ mode of a Lyostar II freeze dryer. Product temperature was elevated to imitate intermediate and aggressive cycle conditions. The final product was analyzed using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Karl Fischer, and modulated differential scanning calorimetry (MDSC), and the life cell count (LCC) during accelerated stability testing. The cakes processed at intermediate and aggressive conditions displayed larger pores with microcollapse of walls and stronger loss in LCC than the conservatively processed product, especially during stability testing. For all process conditions, a loss of the majority of cells was observed during storage. For freeze-drying of life bacterial vaccine solutions, the product temperature profile during primary drying appeared to be inter-related to product quality attributes.

  5. Phase formation of V2O5.xNb2O5 compounds via gels and freeze-dried precursors

    International Nuclear Information System (INIS)

    Langbein, Hubert; Mayer-Uhma, Tobias

    2009-01-01

    An X-ray powder diffraction study of the phase formation in the system V 2 O 5 /Nb 2 O 5 is performed. Freeze-dried ammonium vanadate and ammonium oxalato niobate, alkoxide-derived xerogels and a mixture of active oxides are used as precursors to compare the resulting phase composition. Thermal decomposition of the freeze-dried precursor is monitored with DTA/TG and mass spectrometry. In the quasi-binary system V 2 O 5 -Nb 2 O 5 metastable VNbO 5 , V 4 Nb 18 O 55 , VNb 9 O 25 and solid solutions of V 2 O 5 in TT-Nb 2 O 5 as also thermodynamically stable VNb 9 O 25 exist. The thermal decomposition of freeze-dried vanadate-oxalatoniobate solution allows the synthesis of all these phases in a relative simple manner. Structural relationships between an intermediate phase and the product, or, in the case of solid-state reactions, between one of the starting oxide and the product, favour the desired reaction. Therefore, the structure of a former phase influences or directs the structure of the product similar to a topotactic reaction

  6. Protein crowding in solution, frozen and freeze-dried states: small-angle neutron and X-ray scattering study of lysozyme/sorbitol/water systems

    Science.gov (United States)

    Krueger, Susan; Khodadadi, Sheila; Clark, Nicholas; McAuley, Arnold; Cristiglio, Viviana; Theyencheri, Narayanan; Curtis, Joseph; Shalaev, Evgenyi

    2015-03-01

    For effective preservation, proteins are often stored as frozen solutions or in glassy states using a freeze-drying process. However, aggregation is often observed after freeze-thaw or reconstitution of freeze-dried powder and the stability of the protein is no longer assured. In this study, small-angle neutron and X-ray scattering (SANS and SAXS) have been used to investigate changes in protein-protein interaction distances of a model protein/cryoprotectant system of lysozyme/sorbitol/water, under representative pharmaceutical processing conditions. The results demonstrate the utility of SAXS and SANS methods to monitor protein crowding at different stages of freezing and drying. The SANS measurements of solution samples showed at least one protein interaction peak corresponding to an interaction distance of ~ 90 Å. In the frozen state, two protein interaction peaks were observed by SANS with corresponding interaction distances at 40 Å as well as 90 Å. On the other hand, both SAXS and SANS data for freeze-dried samples showed three peaks, suggesting interaction distances ranging from ~ 15 Å to 170 Å. Possible interpretations of these interaction peaks will be discussed, as well as the role of sorbitol as a cryoprotectant during the freezing and drying process.

  7. Impact of different cryoprotectants on the survival of freeze-dried Lactobacillus rhamnosus and Lactobacillus casei/paracasei during long-term storage.

    Science.gov (United States)

    Jofré, A; Aymerich, T; Garriga, M

    2015-01-01

    The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (≥ 94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ≤ 0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures.

  8. PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

    International Nuclear Information System (INIS)

    Sultana, Naznin; Wang Min

    2012-01-01

    Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(l-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

  9. Spectroscopic investigation of the aggregation state of amphotericin B during loading, freeze-drying, and reconstitution of polymeric micelles.

    Science.gov (United States)

    Adams, Monica; Kwon, Glen S

    2004-11-22

    To investigate the relative aggregation state of amphotericin B (AmB) during loading and reconstitution of polymeric micelles. Hexanoate and stearate derivatives of PEO-b-p (L-Asp) were prepared. The polymers and AmB were dissolved in methanol (MeOH). Milli-Q water was then added slowly, and the MeOH was removed via rotary evaporation. The solutions were freeze-dried in the presence of trehalose. During micelle preparation, the aggregation state of AmB was assessed using absorption spectroscopy. Upon reconstitution, the samples were analyzed using vapor-pressure osmometry, size-exclusion chromatography (SEC), and absorption spectroscopy. The absorption spectrum of AmB in the presence of the block copolymers was compared to that of AmB alone under the same conditions. AmB was loaded into micelles prepared from acyl derivatives of PEO-b-p (L-Asp). Absorption spectroscopy indicated that the aggregation state was preserved during the loading process. AmB exists in a self-aggregated state in polymeric micelles containing hexanoate ester cores and in a relatively monomeric state in polymeric micelles containing stearate ester cores. Vapor-pressure osmometry confirmed the isotonicity of the formulations, while SEC indicated that the micelles were approximately 10(6) g/mol. Depending on the polymer structure and assembly conditions, it is possible to encapsulate AmB in a relatively nonaggregated or aggregated state in micelles prepared from acyl derivatives of PEO-b-p (L-Asp). In polymeric micelles containing stearate side chains, AmB was loaded in a nearly monomeric state, possibly due to interaction with the stearate side chains. The final aggregation state of the drug is preserved during lyophilization and reconstitution of polymeric micelles prepared by a novel solvent evaporation procedure.

  10. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Science.gov (United States)

    Mogharehabed, Ahmad; Birang, Reza; Torabinia, Nakisa; Nasiri, Saman; Behfarnia, Parichehr

    2014-01-01

    Background: The accelerating effect of plasma rich in growth factors (PRGFs) in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA). Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA). Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm). The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm²). The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm²). The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm²). Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant. PMID:25225559

  11. Strategies for multivariate modeling of moisture content in freeze-dried mannitol-containing products by near-infrared spectroscopy.

    Science.gov (United States)

    Yip, Wai Lam; Gausemel, Ingvil; Sande, Sverre Arne; Dyrstad, Knut

    2012-11-01

    Accurate determination of residual moisture content of a freeze-dried (FD) pharmaceutical product is critical for prediction of its quality. Near-infrared (NIR) spectroscopy is a fast and non-invasive method routinely used for quantification of moisture. However, several physicochemical properties of the FD product may interfere with absorption bands related to the water content. A commonly used stabilizer and bulking agent in FD known for variation in physicochemical properties, is mannitol. To minimize this physicochemical interference, different approaches for multivariate correlation between NIR spectra of a FD product containing mannitol and the corresponding moisture content measured by Karl Fischer (KF) titration have been investigated. A novel method, MIPCR (Main and Interactions of Individual Principal Components Regression), was found to have significantly increased predictive ability of moisture content compared to a traditional PLS approach. The philosophy behind the MIPCR is that the interference from a variety of particle and morphology attributes has interactive effects on the water related absorption bands. The transformation of original wavelength variables to orthogonal scores gives a new set of variables (scores) without covariance structure, and the possibility of inclusion of interaction terms in the further modeling. The residual moisture content of the FD product investigated is in the range from 0.7% to 2.6%. The mean errors of cross validated prediction of models developed in the investigated NIR regions were reduced from a range of 24.1-27.6% for traditional PLS method to 15.7-20.5% for the MIPCR method. Improved model quality by application of MIPCR, without the need for inclusion of a large number of calibration samples, might increase the use of NIR in early phase product development, where availability of calibration samples is often limited. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Determination of orthodontic tooth movement and tissue reaction following demineralized freeze-dried bone allograft grafting intervention

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2012-01-01

    Full Text Available Background: Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. Materials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA (CenoBone® was used as the graft material. The defects were made by the extraction of 3 rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM, alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. Results: There was a slight increase in OTM at grafted sites as they were compared to the control sites (P<0.05. Also a significant bone resorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (P<0.05. Conclusion: Using socket preservation, tooth movement can be immediately started without waiting for the healing of the recipient site. This can provide some advantages like enhanced rate of OTM, its approved effects on ridge preservation that reduces the chance of dehiscence and the reduction of root resorption.

  13. Evaluation of spray and freeze dried excipient bases containing disintegration accelerators for the formulation of metoclopramide orally disintegrating tablets

    International Nuclear Information System (INIS)

    Alanazi, Fars K.

    2007-01-01

    Orally disintegrating tablets (ODT) are gaining attractiveness over conventional tablets especially for patients having difficulty in swallowing such as pediatric, geriatric, bedridden and disable patients. ODT technologies render the tablets disintegrate in the mouth without chewing or additional water intake. So far there have been many patents for ODT, but only few publications are dealing with this dosage form. The aim of the present study was to formulate metoclopramide in ODT with sufficient mechanical strength and fast disintegration from bases prepared by both spray (SD) and freeze drying (FD) techniques. Different disintegration accelerators (DA) were utilized to prepare proper ODT using various super-disintegrants (Ac-Di-Sol, Kollidon and Sodium Starch glycolate), a volatilizing solvent (ethanol) and an amino acid (glycine). Metoclopramide, an antiemetic medication, was used a model drug in the formulated ODT. It was noted that the disintegration of ODT depends on utilization of DA in both SD and FD techniques to prepare tablet bases for ODT and so many other factors such as drying processes. The good disintegration property of the prepared tablets was related to the excellent wettability of the ingredients after being subjected to the drying processes. Results also showed that the addition of DA to the tablet bases before drying process results in lengthening of the disintegration time in comparison to their addition to the tablet bases after the drying process. Those findings be utilized for many drugs and they may be considered versatile in their applications. Also, the disintegration of the ODT in the buccal cavity may favor fast absorption via the mucus membrane in the oral cavity. (author)

  14. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Directory of Open Access Journals (Sweden)

    Ahmad Mogharehabed

    2014-01-01

    Full Text Available Background: The accelerating effect of plasma rich in growth factors (PRGFs in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA. Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA. Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm. The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm². The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm². The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm². Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

  15. Effects of Long-Term Simulated Martian Conditions on a Freeze-Dried and Homogenized Bacterial Permafrost Community

    Science.gov (United States)

    Hansen, Aviaja A.; Jenson, Lars L.; Kristoffersen, Tommy; Mikkelsen, Karina; Merrison, Jonathan; Finster, Kai W.; Lomstein, Bente Aa.

    2009-03-01

    Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core, while the number of viable cells was reduced in the upper 15 mm. The number of cultured aerobic bacteria was reduced in the upper 6 mm of the soil core, whereas the community structure of cultured anaerobic bacteria was relatively unaffected by the exposure conditions. As explanations for the observed changes, we propose three causes that might have been working on the biological material either individually or synergistically: (i) UV radiation, (ii) UV-generated reactive oxygen species, and (iii) freeze-thaw cycles. Currently, the production and action of reactive gases is only hypothetical and will be a central subject in future investigations. Overall, we conclude that in a stable environment (no wind-/pressure-induced mixing) biological material is efficiently shielded by a 2 cm thick layer of dust, while it is relatively rapidly destroyed in the surface layer, and that biomolecules like proteins and polynucleotides are more resistant to destruction than living biota.

  16. Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a "pH memory" effect?

    Science.gov (United States)

    Vetráková, Ľubica; Vykoukal, Vít; Heger, Dominik

    2017-09-15

    The concept of "pH memory" has been established in the literature for the correlation between the pH of a pre-lyophilization solution and the ionization state of freeze-dried powder (lyophile). In this paper, the concept of "pH memory" is explored for the system of an aqueous solution, a frozen solution, and a lyophile. Sodium and potassium phosphate buffers in the pH range of 5-9 were frozen and lyophilized with sulfonephthalein indicators as acidity probes, and their Hammett acidity functions were compared to the initial pH of the aqueous solution. The results show that the acidities of the lyophiles are somewhat changed compared to the initial pHs, but the acidities in the frozen state differ more substantially. The Hammett acidity functions of the frozen buffers were found to be markedly dissimilar from the initial pH, especially in the sodium phosphate frozen at 233K, where an increase in the initial pH led to a decrease in the Hammett acidity function of the frozen state at a certain pH range. The large acidification observed after freezing the sodium phosphate buffer was not detected in the lyophiles after the sample had been dried; the phenomenon is explained considering the formed crystals analyzed by X-ray powder diffraction. The results suggest that monitoring the final acidity of a lyophile is not sufficient to predict all the acidity changes throughout the whole lyophilization process. The importance of well-controlled freezing and lyophilization conditions follows from the results of the research. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Radiosterilization or sterilization by steam. Procedures for sterilization of spices

    International Nuclear Information System (INIS)

    Warmbold, J.

    1994-01-01

    The article compares two different methods for the sterilization of spices, namely radiosterilization and sterilization with steam. The first method applies ionizing radiation which can alter the chemical composition of the products. Tests have shown, however, that radiation doses up to 10 kGy will not induce the formation of carcinogenic agents in the foodstuffs, or of toxic substances, and thus are a wholesome method of preservation. Any modifications of taste, color or smell, or loss of vitamins, can be avoided by proper dose control and standard irradiation conditions. Sterilization by steam is a method achieving substantial suppression of the formation of germs, aerobic spores, yeasts, mould, and gramnegative germs, while preserving in most cases the essential oils. It may result in sensoric alterations, i.e affect the color, smell or taste, but in general the spices thus treated preserved their characteristic properties. The method is a good alternative to radiosterilization. The article adds some concluding information on mandatory labelling of irradiated food imported from third countries

  18. Present studies on the radio-sterilized drugs; Aktualny stan badan nad lekami sterylizowanymi radiacyjnie

    Energy Technology Data Exchange (ETDEWEB)

    Marciniec, B; Dettlaff, K [Department of Pharmaceutical Chemistry, Poznan University of Medical Sciences, Poznan (Poland)

    2007-07-01

    Lecture presents present status of radiosterilization of drugs and medical materials as compared to other sterilization methods. Literature review is shown on degradation of different kinds of drugs sterilized upon action of the sterilising doses of radiation.

  19. Requirements concerning radiosterilization process organization; Wymagania dotyczace organizacji procesu sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Kaluska, I [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Administrative procedure connecting for licensing new materials or consumer products appropriated to radiosterilization have been performed and explained. Also the organization of irradiation process for attaining the proper result have been described in detail. 4 refs, 1 tab.

  20. Spray-freeze-drying of nanosuspensions: the manufacture of insulin particles for needle-free ballistic powder delivery

    Science.gov (United States)

    Schiffter, Heiko; Condliffe, Jamie; Vonhoff, Sebastian

    2010-01-01

    The feasibility of preparing microparticles with high insulin loading suitable for needle-free ballistic drug delivery by spray-freeze-drying (SFD) was examined in this study. The aim was to manufacture dense, robust particles with a diameter of around 50 µm, a narrow size distribution and a high content of insulin. Atomization using ultrasound atomizers showed improved handling of small liquid quantities as well as narrower droplet size distributions over conventional two-fluid nozzle atomization. Insulin nanoparticles were produced by SFD from solutions with a low solid content (ballistic injection, the insulin nanoparticles were suspended in matrix formulations with a high excipient content (>300 mg ml−1) consisting of trehalose, mannitol, dextran (10 kDa) and dextran (150 kDa) (abbreviated to TMDD) in order to maximize particle robustness and density after SFD. With the increase in insulin content, the viscosity of the nanosuspensions increased. Liquid atomization was possible up to a maximum of 250 mg of nano-insulin suspended in a 1.0 g matrix. However, if a narrow size distribution with a good correlation between theoretical and measurable insulin content was desired, no more than 150 mg nano-insulin could be suspended per gram of matrix formulation. Particles were examined by laser light diffraction, scanning electron microscopy and tap density testing. Insulin stability was assessed using size exclusion chromatography (SEC), reverse phase chromatography and Fourier transform infrared (FTIR) spectroscopy. Densification of the particles could be achieved during primary drying if the product temperature (Tprod) exceeded the glass transition temperature of the freeze concentrate (Tg′) of −29.4°C for TMDD (3∶3∶3∶1) formulations. Particles showed a collapsed and wrinkled morphology owing to viscous flow of the freeze concentrate. With increasing insulin loading, the d (v, 0.5) of the SFD powders increased and particle size distributions got wider

  1. Spray-freeze-drying of nanosuspensions: the manufacture of insulin particles for needle-free ballistic powder delivery.

    Science.gov (United States)

    Schiffter, Heiko; Condliffe, Jamie; Vonhoff, Sebastian

    2010-08-06

    The feasibility of preparing microparticles with high insulin loading suitable for needle-free ballistic drug delivery by spray-freeze-drying (SFD) was examined in this study. The aim was to manufacture dense, robust particles with a diameter of around 50 microm, a narrow size distribution and a high content of insulin. Atomization using ultrasound atomizers showed improved handling of small liquid quantities as well as narrower droplet size distributions over conventional two-fluid nozzle atomization. Insulin nanoparticles were produced by SFD from solutions with a low solid content (300 mg ml(-1)) consisting of trehalose, mannitol, dextran (10 kDa) and dextran (150 kDa) (abbreviated to TMDD) in order to maximize particle robustness and density after SFD. With the increase in insulin content, the viscosity of the nanosuspensions increased. Liquid atomization was possible up to a maximum of 250 mg of nano-insulin suspended in a 1.0 g matrix. However, if a narrow size distribution with a good correlation between theoretical and measurable insulin content was desired, no more than 150 mg nano-insulin could be suspended per gram of matrix formulation. Particles were examined by laser light diffraction, scanning electron microscopy and tap density testing. Insulin stability was assessed using size exclusion chromatography (SEC), reverse phase chromatography and Fourier transform infrared (FTIR) spectroscopy. Densification of the particles could be achieved during primary drying if the product temperature (T(prod)) exceeded the glass transition temperature of the freeze concentrate (T(g)') of -29.4 degrees C for TMDD (3331) formulations. Particles showed a collapsed and wrinkled morphology owing to viscous flow of the freeze concentrate. With increasing insulin loading, the d (v, 0.5) of the SFD powders increased and particle size distributions got wider. Insulin showed a good stability during the particle formation process with a maximum decrease in insulin monomer of

  2. Freeze-dried plasma enhances clot formation and inhibits fibrinolysis in the presence of tissue plasminogen activator similar to pooled liquid plasma.

    Science.gov (United States)

    Huebner, Benjamin R; Moore, Ernest E; Moore, Hunter B; Sauaia, Angela; Stettler, Gregory; Dzieciatkowska, Monika; Hansen, Kirk; Banerjee, Anirban; Silliman, Christopher C

    2017-08-01

    Systemic hyperfibrinolysis is an integral part of trauma-induced coagulopathy associated with uncontrolled bleeding. Recent data suggest that plasma-first resuscitation attenuates hyperfibrinolysis; however, the availability, transport, storage, and administration of plasma in austere environments remain challenging and have limited its use. Freeze-dried plasma (FDP) is a potential alternative due to ease of storage, longer shelf life, and efficient reconstitution. FDP potentially enhances clot formation and resists breakdown better than normal saline (NS) and albumin and similar to liquid plasma. Healthy volunteers underwent citrated blood draw followed by 50% dilution with NS, albumin, pooled plasma (PP), or pooled freeze-dried plasma (pFDP). Citrated native and tissue plasminogen activator (t-PA)-challenge (75 ng/mL) thrombelastography were done. Proteins in PP, pFDP, and albumin were analyzed by mass spectroscopy. pFDP and PP had superior clot-formation rates (angle) and clot strength (maximum amplitude) compared with NS and albumin in t-PA-challenge thrombelastographies (angle: pFDP, 67.9 degrees; PP, 67.8 degrees; NS, 40.6 degrees; albumin, 35.8 degrees; maximum amplitude: pFDP, 62.4 mm; PP, 63.5 mm; NS, 44.8 mm; albumin, 41.1 mm). NS and albumin dilution increased susceptibility to t-PA-induced hyperfibrinolysis compared with pFDP and PP (NS, 62.4%; albumin, 62.6%; PP, 8.5%; pFDP, 6.7%). pFDP was similar to PP in the attenuation of t-PA-induced fibrinolysis. Most proteins (97%) were conserved during the freeze-dry process, with higher levels in 12% of pFDP proteins compared with PP. pFDP enhances clot formation and attenuates hyperfibrinolysis better than NS and albumin and is a potential alternative to plasma resuscitation in the treatment of hemorrhagic shock. © 2017 AABB.

  3. Effects of hot air and freeze drying methods on antioxidant activity, colour and some nutritional characteristics of strawberry tree (Arbutus unedo L) fruit.

    Science.gov (United States)

    Orak, H H; Aktas, T; Yagar, H; İsbilir, S Selen; Ekinci, N; Sahin, F Hasturk

    2012-08-01

    Antioxidant activity, colour and some nutritional properties of hot air and freeze-dried strawberry tree (Arbutus unedo L.) fruits were investigated. Additionally, the effects of two pre-treatments, namely ethyl oleate and water blanching, were compared in terms of drying characteristics. For determination of antioxidant activities in ethanol extracts, two different analytical methods were used: 1,1-diphenyl-2-picrylhydrazyl scavenging activity and β-carotene bleaching activity. As a result, the ethyl oleate pre-treatment shortened the drying time by hot air method and gave a higher 1,1-diphenyl-2-picrylhydrazyl scavenging activity (82.16 ± 0.34%), total phenolic content (7.62 ± 1.09 µg GAE/g extract), ascorbic acid content (236.93 ± 20.14 mg/100 g), besides hydromethylfurfural was not observed. Freeze-dried fruits exhibited higher ascorbic acid content (368.63 ± 17.16 mg/100 g) than those fresh fruits (231.33 ± 19.51 mg/100 g) and nearly 1,1-diphenyl-2-picrylhydrazyl activity (93.52 ± 0.41 %) to fresh fruits (94.03 ± 1.18%). Colour characteristics, sugar content and mineral contents of fruits were significantly affected by pre-treatments and drying methods (p drying of strawberry tree fruits should bring a valuable and attractive foodstuff to food industry due to the rich nutritional components, antioxidant activity and colour. Another conclusion from this study is that the freeze-drying is the best drying method to keep the nutritional value, antioxidant activity and sensory properties of fruits.

  4. Effect of baking and steaming on physicochemical and thermal properties of sweet potato puree preserved by freezing and freeze-drying

    Directory of Open Access Journals (Sweden)

    Bernarda Svrakačić

    2016-01-01

    Full Text Available Thermal treatments could be one of the hurdles in applications of sweet potato purees for food different products formulation. Sweet potato purees (SPP were prepared from raw, baked and steamed roots and they were preserved by freezing and freeze-drying. The effects of baking and steaming on thermal properties (melting temperature-Tm, melting transition energy - ΔH, and glass transition temperatures - Tg of sweet potato (cultivar Beauregard, were measured by means of a Differential scanning calorimetry (DSC. The SPP made from baked roots had higher total and soluble solids (20.32 and 18.95%, respectively than SPP made from raw and steamed roots. It can be also noticed that starch content was reduced by steaming and baking which reflected on amount of total and reducing sugars. The increase of reducing sugars level in baked SPP for 3.78% and steamed for 0.86% SPP was the result of yielding the maltose. The chemical changes of SPP also influenced the thermal behavior such that SPP prepared from baked sweet potato roots had the lowest initial freezing point (-2.80 °C followed by SPP prepared from steamed (-2.63 °C and raw (-0.71 °C roots. The highest energy for melting (transition was needed for SPP prepared from raw potato roots followed by steamed and baked roots, -103.79, -103.63, and -102.90 J/g, respectively. The glass transition in freeze-dried SPP prepared from raw roots was not detected. However, in the freeze-dried SPP prepared from baked and steamed roots the glass transition was detected in the range of 39 and 42 °C but with no significant difference (p > 0.05.

  5. Application of Optical Coherence Tomography Freeze-Drying Microscopy for Designing Lyophilization Process and Its Impact on Process Efficiency and Product Quality.

    Science.gov (United States)

    Korang-Yeboah, Maxwell; Srinivasan, Charudharshini; Siddiqui, Akhtar; Awotwe-Otoo, David; Cruz, Celia N; Muhammad, Ashraf

    2018-01-01

    Optical coherence tomography freeze-drying microscopy (OCT-FDM) is a novel technique that allows the three-dimensional imaging of a drug product during the entire lyophilization process. OCT-FDM consists of a single-vial freeze dryer (SVFD) affixed with an optical coherence tomography (OCT) imaging system. Unlike the conventional techniques, such as modulated differential scanning calorimetry (mDSC) and light transmission freeze-drying microscopy, used for predicting the product collapse temperature (Tc), the OCT-FDM approach seeks to mimic the actual product and process conditions during the lyophilization process. However, there is limited understanding on the application of this emerging technique to the design of the lyophilization process. In this study, we investigated the suitability of OCT-FDM technique in designing a lyophilization process. Moreover, we compared the product quality attributes of the resulting lyophilized product manufactured using Tc, a critical process control parameter, as determined by OCT-FDM versus as estimated by mDSC. OCT-FDM analysis revealed the absence of collapse even for the low protein concentration (5 mg/ml) and low solid content formulation (1%w/v) studied. This was confirmed by lab scale lyophilization. In addition, lyophilization cycles designed using Tc values obtained from OCT-FDM were more efficient with higher sublimation rate and mass flux than the conventional cycles, since drying was conducted at higher shelf temperature. Finally, the quality attributes of the products lyophilized using Tc determined by OCT-FDM and mDSC were similar, and product shrinkage and cracks were observed in all the batches of freeze-dried products irrespective of the technique employed in predicting Tc.

  6. Survival rate of Saccharomyces boulardii adapted to a functional freeze-dried yoghurt, related to processing, storage and digestion by experimental Wistar rats

    Directory of Open Access Journals (Sweden)

    Eunice Tranquilino-Rodriguez

    2017-02-01

    Full Text Available Background: Saccharomycesboulardiiis a probiotic clinically effective inthe prevention and treatment of antibiotic induced diarrheain both children and adults, Clostridium difficile infections, inflammatory bowel disease, and other gastrointestinal disorders. However, the microorganisms need to survive the gastrointestinal transit and arrive to their action site alive in order to exert their beneficial effects. Microencapsulation is an alternative to improve the viability of probiotic in foods which can also survive in the gastrointestinal conditions. Freeze--drying is a method of dehydration that does not affect nutrients and bioactive compounds,such as probiotics contained in foods.All of them will increase the survival rate of S.boulardii.Purpose of this study:This study focused on formulae freeze-dried yogurt containing inulin, vegetable palm oil,and S.boulardii, both asfree cells and in microencapsulated form.Also,the effect of ampicillin associated S.boulardii. Methods. Yogurts were given to an “in vivo” digestion process, using male Wistar rats.The survival of S. boulardiiwas subsequently evaluated in colon and feces.For this study, six treatmentsof four of rats were used:i control rats ii rats fed with yogurt containing S. boulardiias free cells, iii rats fed with yogurt containing S. boulardiiinmicro-encapsulated form, iv control rats fed with penicillin,v rats fed with ampicillin plus yogurtcontaining S. boulardiias free cells, and vi rats fed with penicillin plus yogurt containing S. boulardiiin micro-encapsulated form. Results:The study demonstrated it was feasible to freeze-drythe S. boulardiiand incorporate it into a yogurtmade with skim milk,inulin, and unsaturated vegetable oil.The freeze-drying process not affected thesurvival of the S. boulardii(p<0.05. Microencapsulation increased the survival of S. boulardii on 1.77-Log CFU/g, and the presence of S. boulardii was only detected in colon and fecesof those rats which

  7. Factors affecting the stability and biodistribution of {sup 99m} Tc labelled Sn-pyrophosphate freeze dried kits in normal mice.

    Energy Technology Data Exchange (ETDEWEB)

    Elkolaly, M T; Elwatery, A S; Elghany, E A [Radioisotope production and labelled compounds department, hot lab. center, Atomic Energy Authority, Cairo, (Egypt)

    1995-10-01

    The present study has shown that about 5% of Sn (II) in {sup 99m} Tc labelled Sn-pyrophosphate (Sn-PYP) freeze dried kit was oxidized during kit formulation. Also, {gamma}-irradiation doses of 25 and 50 KGy led to Sn (II) losses of about 9.8 and 27.7%, respectively. In-vitro stability and radiochemical purity were biologically confirmed in mice and a high quality scan was achieved on waiting for 3 hours after injection. 3 figs., 6 tabs.

  8. A botanical containing freeze dried açai pulp promotes healthy aging and reduces oxidative damage in sod1 knockdown flies

    OpenAIRE

    Laslo, Mara; Sun, Xiaoping; Hsiao, Cheng-Te; Wu, Wells W.; Shen, Rong-Fong; Zou, Sige

    2012-01-01

    Superoxide dismutase 1 (SOD1), a critical enzyme against oxidative stress, is implicated in aging and degenerative diseases. We previously showed that a nutraceutical containing freeze-dried açai pulp promotes survival of flies fed a high-fat diet or sod1 knockdown flies fed a standard diet. Here, we investigated the effect of açai supplementation initiated at the early or late young adulthood on lifespan, physiological function, and oxidative damage in sod1 knockdown flies. We found that Aça...

  9. Comparative study of two drying techniques used in radioactive source preparation: Freeze-drying and evaporation using hot dry nitrogen jets

    International Nuclear Information System (INIS)

    Branger, T.; Bobin, C.; Iroulart, M.-G.; Lepy, M.-C.; Le Garreres, I.; Morelli, S.; Lacour, D.; Plagnard, J.

    2008-01-01

    Quantitative solid sources are used widely in the field of radionuclide metrology. With the aim to improve the detection efficiency for electrons and x-rays, a comparative study between two source drying techniques has been undertaken at LNE-Laboratoire National Henri Becquerel (LNE-LNHB, France). In this paper, freeze-drying using commercial equipment is compared with a system of drying using hot jets of nitrogen developed at Institute for Reference Materials and Measurements (IRMM, Belgium). In order to characterize the influence of self-absorption, the detection efficiencies for 51 Cr sources have been measured by coincidence counting and photon spectrometry

  10. The effect of sublethal injury by heating, freezing, drying and gamma-radiation on the duration of the lag phase of Salmonella typhimurium

    International Nuclear Information System (INIS)

    Mackey, B.M.; Derrick, C.M.

    1982-01-01

    The duration of the lag phase of Salmonella typhimurium surviving heat, freezing, drying and gamma-radiation was used to indicate the time needed to repair sublethal injury. Following equivalent lethal treatments, heat and freeze-injured cells needed longer to repair than those injured by drying or gamma-radiation. Measurement of repair on membrane filters showed that in a heat-injured population having a lag time of 9 h, some individual cells needed up to 14 h to recover maximum tolerance to 3% NaCl. (author)

  11. Radiosterilization of Medical Products and Recommended Code of Practice. Proceedings of a Symposium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-09-15

    Proceedings of a Symposium organized by the IAEA and held in Budapest, 5-9 June 1967, together with the IAEA recommended 'Code of Practice for Radiosterilization of Medical Products' resulting from a panel meeting held in Vienna, December 1966, and considered at the Symposium. The meeting was attended by 160 participants from 25 Member States and 3 international organizations. The commercial use of ionizing radiation for sterilizing medical supplies extends back to the early 1960s. The ability of the process to sterilize products made of materials such as plastics, which are destroyed by traditional sterilization procedures, has promoted much new thinking in product design. Most important is the ability of the radiation to sterilize items finally sealed and packed for dispatch, eliminating risk of recontamination. Some new fields of research are discussed in the Proceedings. The Code of Practice, drawn up by experts at several meetings, is aimed at producing uniform, safe procedures throughout the world, facilitating international trade in radiosterilized products. Contents: Introductory lecture; Radiosterilization of pharmaceuticals and bioproducts (12 papers); Radiosterilization of biological tissues (6 papers); Vaccine production by ionizing radiation (5 papers); Radiosterilization of medical devices and supplies (4 papers); Radiosensitivity of micro-organisms and microbiological testing (4 papers); Technical and economic aspects of radiosterilization (6 papers); Code of practice for radiosterilization (full code and 1 review paper). The Code of Practice is in English. Each paper is in its original language (29 English, 5 French, 4 Russian and 1 Spanish) and is preceded by an abstract in English with one in the original language if this is not English. Discussions are in English. (author)

  12. Radiosterilization of Medical Products and Recommended Code of Practice. Proceedings of a Symposium

    International Nuclear Information System (INIS)

    1967-01-01

    Proceedings of a Symposium organized by the IAEA and held in Budapest, 5-9 June 1967, together with the IAEA recommended 'Code of Practice for Radiosterilization of Medical Products' resulting from a panel meeting held in Vienna, December 1966, and considered at the Symposium. The meeting was attended by 160 participants from 25 Member States and 3 international organizations. The commercial use of ionizing radiation for sterilizing medical supplies extends back to the early 1960s. The ability of the process to sterilize products made of materials such as plastics, which are destroyed by traditional sterilization procedures, has promoted much new thinking in product design. Most important is the ability of the radiation to sterilize items finally sealed and packed for dispatch, eliminating risk of recontamination. Some new fields of research are discussed in the Proceedings. The Code of Practice, drawn up by experts at several meetings, is aimed at producing uniform, safe procedures throughout the world, facilitating international trade in radiosterilized products. Contents: Introductory lecture; Radiosterilization of pharmaceuticals and bioproducts (12 papers); Radiosterilization of biological tissues (6 papers); Vaccine production by ionizing radiation (5 papers); Radiosterilization of medical devices and supplies (4 papers); Radiosensitivity of micro-organisms and microbiological testing (4 papers); Technical and economic aspects of radiosterilization (6 papers); Code of practice for radiosterilization (full code and 1 review paper). The Code of Practice is in English. Each paper is in its original language (29 English, 5 French, 4 Russian and 1 Spanish) and is preceded by an abstract in English with one in the original language if this is not English. Discussions are in English. (author)

  13. A novel freeze-dried storage and preparation method for the determination of mycophenolic acid in plasma by high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Lei; Qiang, Wei; Li, Ying; Cheng, Zeneng; Xie, Mengmeng

    2017-09-01

    Plasma samples were conventionally stored at freezing conditions until the time of detection. Such a technique, when carried out over an extended period, is energy consuming; in addition, preparation and transportation of stored samples is inconvenient. In this study, a freeze-dried storage and preparation method was proposed to determine the presence of mycophenolic acid (MPA) in plasma. Fresh plasma samples were freeze-dried using a device, and then stored at ambient temperature. After the stored samples were soaked with methanol spiked with the internal standard, high-performance liquid chromatography was conducted to detect MPA. The proposed method was demonstrated to be precise and accurate over the linear range of 0.5-50 μg mL -1 , with both intra- and inter-day precision being plasma concentration, time point of maximum plasma concentration and elimination half-life, among others, were consistent with the results in the published study. This proposed technique was proved to be simple, reproducible and energy saving. This approach could also simplify the storage and analysis of samples in clinical and scientific drug research. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Influence of the freezing process on the pore structure of freeze-dried collagen sponges; Einfluss des Einfriervorganges auf die Porenstruktur gefriergetrockneter Kollagenschwaemme

    Energy Technology Data Exchange (ETDEWEB)

    Schoof, H.; Bruns, L.; Apel, J.; Heschel, I.; Rau, G. [Helmholz-Inst. fuer Biomedizinische Technik, Aachen (Germany)

    1997-12-31

    Freeze-dried sponges are used as colonisable tissue implants. As their porous structure is important for rapid colonisation it was found desirable to be able to produce homogeneous pore structures to specification. The structure of freeze-dried sponges is largely the same as the ice crystal morphology of frozen samples. In industrial manufacture suspensions are solidified in a cold bath. Freezing conditions are not stationary in this process, rendering ice crystal morphology inhomogeneous. However, studies on directed solidification as it is used in the Bridgman or the power-down method have shown that certain freezing conditions permit the production of collagen sponges of homogenous predefined pore size. [Deutsch] Gefriergetrocknete Kollagenschwaemme werden als besiedelbare Gewebeimplantate eingesetzt. Da die poroese Struktur fuer eine zuegige Besiedelung von grosser Bedeutung ist, sollen Kollagenschwaemme mit einer einstellbaren und homogenen Porenstruktur hergestellt werden. Die Struktur der gefriergetrockneten Schwaemme entspricht weitestgehend der Eiskristallmorphologie der gefrorenen Probe. Bei der industriellen Herstellung werden Suspensionen in einem Kaeltebad erstarrt. Die Einfrierbedingungen sind dabei nicht stationaer, was zu einer inhomogenen Eiskristallmorphologie fuehrt. Untersuchungen zur gerichteten Erstarrung nach dem Bridgman- und dem Power-Down-Verfahren ergaben jedoch, dass unter bestimmten Einfrierbedingungen Kollagenschwaemme mit homogener und definierbarer Porengroesse hergestellt werden koennen. (orig.)

  15. A comparative evaluation of extraction socket preservation with demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Dhaval J Thakkar

    2016-01-01

    Full Text Available Aims: To investigate clinically and radiographically, the bone fill in extraction sockets using demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin (PRF. Materials and Methods: A randomized controlled clinical trial was carried out on 36 nonrestorable single-rooted teeth sites. Sites were randomized into demineralized freeze-dried bone allograft (DFDBA combined with PRF - test and DFDBA - control groups using a coin toss method. After the placement of graft material, collagen membrane was used to cover it. The clinical parameters recorded were ridge width and ridge height. All the parameters were recorded at baseline and at 90 and 180 days. Statistical Analysis Used: Independent t-test and paired t-test. Results: In both groups, there is significant reduction in loss of ridge width and ridge height from baseline to 90 days (P < 0.001, baseline to 180 days (P < 0.001, and 90-180 days (P < 0.001. However, when both the groups were compared the test group favored in the reduction of ridge width while there was no statistical difference in reduction of ridge height among at different intervals. Conclusions: Although DFDBA is considered as an ideal graft material, PRF can be used as an adjunctive with DFDBA for socket preservation.

  16. The Resistance to Freeze-Drying and to Storage Was Determined as the Cellular Ability to Recover Its Survival Rate and Acidification Activity

    Directory of Open Access Journals (Sweden)

    Ibourahema Coulibaly

    2010-01-01

    Full Text Available The protective effects of the fatty acid composition and membrane action of the acidification activity of two strains of Lactobacillus kept at 20∘C were studied. The addition of sorbitol, monosodium glutamate and glycerol during storage is causing the decline of acidification and increased concentrations of unsaturated fatty acids observed in both strains. The addition of sorbitol and monosodium glutamate does not alter the fatty acid composition, whatever the strain, but increases the resistance to freeze-drying of L. plantarum CWBI-B1419 and improves survival during storage. The addition of these preservatives and decreased activity of acidification improves the ratio unsaturated. These results indicate that the survival during storage and freeze-drying resistance are closely related to the composition of membrane fatty acids. This behaviour can be interpreted as an adaptation of L. plantarum B1419-CWBI supplemented by cryoprotectant additives such as sorbitol or monosodium glutamate sorbitol and monosodium glutamate as an additive. L. plantarum CWBI-B1419 presents a greater adaptation to culture conditions than L. paracasei ssp. paracasei LMG9192T.

  17. An Insight into the Convenience and Efficiency of the Freeze-Drying Route to Construct 3D Graphene-Based Hybrids for Lithium-Ion Batteries

    International Nuclear Information System (INIS)

    Ding, Caihua; Zhao, Yongjie; Yan, Dong; Zhao, Yuzhen; Zhou, Heping; Li, Jingbo; Jin, Haibo

    2016-01-01

    Constructing hybrids of transition metal oxides with different kinds of carbon based materials has attracted a lot of attention recently. However, scalable synthesis of homogeneous hybrids with active controllable of microstructure remains great challenge. Here, we proposed a convenient and efficient strategy named freeze-drying process for scalable production of 3D NiO/graphene hybrids. With a controllable procedure, NiO microflowers and graphene layers could preserve uniform configuration from fully mixed solvent to final hybrids materials. The mechanical stability and electrical conductivity of NiO microflowers was increased by graphene. NiO microflowers as spacers intercalated into graphene layers and effectively prevented it from aggregation or restacking, leading to a high specific surface area in hybrids. The NiO/graphene exhibited enhanced cycle stability and rate performance when evaluated as an anode for lithium ion batteries. It rendered high specific capacities about 1000 mA h g −1 after 70 cycles, and 770 mA h g −1 after 100 cycles at 300 mA g −1 . Excellent electrochemical properties were probably ascribed to the synergistic effect of NiO microflowers and graphene layers, as a result of smart structure design by a freeze-drying route. This strategy with merits of rational construction and scalable production could establish new aspects for diverse hybrid towards industrialization.

  18. Freeze drying synthesis of Li{sub 3}MnO{sub 4} cathode material for Li-ion batteries: A physico-electrochemical study

    Energy Technology Data Exchange (ETDEWEB)

    Surace, Yuri; Simões, Mário; Karvonen, Lassi; Yoon, Songhak; Pokrant, Simone [Laboratory Materials for Energy Conversion, EMPA – Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Weidenkaff, Anke, E-mail: weidenkaff@imw.uni-stuttgart.de [Materials Chemistry, Institute for Materials Science, University of Stuttgart, Heisenbergstrasse 3, DE-70569 Stuttgart (Germany)

    2015-09-25

    Highlights: • Facilitated synthesis of Li{sub 3}MnO{sub 4} with a smaller thermal budget via freeze drying. • Electrochemical activity enhanced by micro- and nanostructure modifications. • Capacity increase of 30% at 1st discharge versus standard synthesis process. - Abstract: Li{sub 3}MnO{sub 4}, a lithium rich phase containing manganese (V), is a promising cathode material for Li-ion batteries due to its very high theoretical capacity (698 A h kg{sup −1}). Li{sub 3}MnO{sub 4} was synthesized from freeze dried precursors at 398 K. Combined structural, morphological and chemical characterization by XRD, TGA, SEM, TEM and XPS revealed improvements in the micro- and nanostructure in comparison to the material synthesized by a standard solid state chemistry route. The average particle size decreased from 10 μm to 3.5 μm and the average crystallite size from close to 100 nm to around 30 nm. These modifications enhanced the capacity (23% at 10 A kg{sup −1} and up to 31% at 50 A kg{sup −1} with a maximum discharge capacity of 290 A h kg{sup −1}) and the rate capability.

  19. Encapsulation of antioxidant phenolic compounds extracted from spent coffee grounds by freeze-drying and spray-drying using different coating materials.

    Science.gov (United States)

    Ballesteros, Lina F; Ramirez, Monica J; Orrego, Carlos E; Teixeira, José A; Mussatto, Solange I

    2017-12-15

    Freeze-drying and spray-drying techniques were evaluated for encapsulation of phenolic compounds (PC) extracted from spent coffee grounds. Additionally, the use of maltodextrin, gum arabic and a mixture of these components (ratio 1:1) as wall material to retain the PC and preserve their antioxidant activity was also assessed. The contents of PC and flavonoids (FLA), as well as the antioxidant activity of the encapsulated samples were determined in order to verify the efficiency of each studied condition. Additional analyses for characterization of the samples were also performed. Both the technique and the coating material greatly influenced the encapsulation of antioxidant PC. The best results were achieved when PC were encapsulated by freeze-drying using maltodextrin as wall material. Under these conditions, the amount of PC and FLA retained in the encapsulated sample corresponded to 62% and 73%, respectively, and 73-86% of the antioxidant activity present in the original extract was preserved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effect of Hot-Water Blanching Pretreatment on Drying Characteristics and Product Qualities for the Novel Integrated Freeze-Drying of Apple Slices

    Directory of Open Access Journals (Sweden)

    Hai-ou Wang

    2018-01-01

    Full Text Available The effect of hot-water blanching (HWB on drying characteristics and product qualities of dried apple slices with the novel integrated freeze-drying (NIFD process was investigated by comparing with 3 different FD methods. Compared with the NIFD process without HWB pretreatment (VF-FD, the NIFD process with HWB pretreatment (HWB-VF-FD resulted in a significantly higher mass loss and more sufficient freezing in vacuum-frozen samples, significantly higher rehydration ratio (RR, higher shrinkage ratio (SR, smaller Vitamin C (VC content and lower hardness and better apparent shape in freeze-dried samples, and fewer change to the color of the dried or rehydrated samples (p<0.05. Compared with the conventional FD process with HWB pretreatment (HWB-PF-FD, HWB-VF-FD cost significantly less processing time and FD time and obtained significantly higher RR (p<0.05, almost the equivalent SR, VC content, and hardness, and similar appearance in dried samples. The microstructure of apple cell tissues was analyzed by transmission electron microscopy and scanning electron microscopy to interpret the above differences in drying characteristics and product qualities. The results suggested that the NIFD process of apple slices with HWB pretreatment was a promising alternative method to decrease drying time, achieve similar product quality, and simplify the process steps of the conventional FD technology.

  1. Investigation of optimal manufacturing process for freeze-dried formulations: Observation of frozen solutions by low temperature X-ray diffraction measurements

    International Nuclear Information System (INIS)

    Egawa, Hiroaki; Yonemochi, Etsuo; Terada, Katsuhide

    2005-01-01

    Freeze-drying is used for the production of sterile injections in the pharmaceutical industry. However, most pharmaceutical compounds are obtained as less stable amorphous form. Freeze crystallization by annealing is an effective method for pharmaceutical compounds that fail to crystallize in the freeze-drying process. Crystallization occurs in the frozen solution during the thermal treatment. In order to establish suitable annealing conditions efficiently, it is important to observe the crystallization process directly in the frozen solution. Recently, low temperature X-ray diffraction has been used to observe frozen solutions. In order to investigate the crystallization process kinetically, the temperature of the low temperature X-ray diffraction instrument must be accurately controlled. We calibrated the temperature of X-ray diffraction instrument by measuring eutectic temperatures of solutions for a series of compounds. Each eutectic crystal was observed in frozen solution with ice crystal below the eutectic temperature. Eutectic temperatures were detected by the decrease in diffraction intensity associated with heating from below the eutectic temperature. Good correlation was obtained between values in the literature and experimental values

  2. Criteria for permission of radiosterilized products to application in medicine; Zasady dopuszczania wyrobow sterylizowanych radiacyjnie do stosowania w medycynie

    Energy Technology Data Exchange (ETDEWEB)

    Achmatowicz, T [Instytut Lekow, Warsaw (Poland)

    1997-10-01

    The criteria being used in Poland for permission of radiosterilized medical materials to commercial application result from regulations being in force. The international regulations are also taken into account. The all criteria and procedure needed for any product become accepted for radiosterilization and commercial medical use have been presented and discussed. 1 tab.

  3. Bone regeneration: in vitro evaluation of the behaviour of osteoblast-like MG63 cells placed in contact with polylactic-co-glycolic acid, deproteinized bovine bone and demineralized freeze-dried bone allograft.

    Science.gov (United States)

    Pappalardo, S; Mastrangelo, F; Reale Marroccia, D; Cappello, V; Ciampoli, C; Carlino, V; Tanteri, L; Costanzo, M; Sinatra, F; Tetè, S

    2008-01-01

    Insufficient bone density of the alveolar crests, caused by loss of the dental elements, sometimes impedes the primary stability of an integrated bone implant. The techniques of bone regeneration allow to obtain a sufficient quantity of alveolar bone to permit the implant rehabilitation of the edentulous crests. Today several grafting materials are available and they have different characteristics, according to their structure, which influence the different behaviour of the grafting materials to the bone and the implant surface. The aim of this study is to evaluate the interaction between a human osteosarcoma MG63 cell line and three different biomaterials: polylactic-co-glycolic acid (PLAGA), deproteinized bovine bone and demineralised freeze-dried bone allograft (DFDBA). From this study a different behaviour emerges of the osteoblast-like MG63 cells in relation to the sublayer on which these cells were placed in culture. The results of the study, in fact, demonstrate that the most osteoconductive material of the three analysed is the DFDBA, followed by DPBB. On the contrary, the PLGA, because of its roughness, does not seem to represent a valid support for cell growth, and does not encourage any morphologic modification in tumor cells. Furthermore, deproteinized bovine bone shows a differentiating effect which could lead to hypothesise an osteoconductive capacity of this biomaterial. Further studies should be carried out with the aim of explaining the results obtained.

  4. Radiosterilization and steam autoclaving sterilization effects on phosphite antioxidant stability

    International Nuclear Information System (INIS)

    Yagoubi, N.; Boucherie, P.; Ferrier, D.

    1997-01-01

    While the radiosterilization by γ rays, is mainly employed for medical devices, this procedure is not commonly used to sterilize and decontaminate raw material and finished product used in the pharmaceutical industry. Depending on the countries, the requirements for obtaining approval to treat this class of product with γ rays may be different. Usually it is the responsibility of the manufacturer to demonstrate not only the integrity of the irradiated product, but olso its efficiency, safety and quality. Our work consists of a comparative study of the effects of γ radiotreatment at 25 kGy and steam sterilisation on phosphite antioxidant incorporated in polypropylene. The γ radiosensitivity compared with thermolability of this antioxidant was studied by reversed phase HPLC, Fourier transform infrared (IRFT) and differential scanning calorimetry (DSC). The results obtained proved that the phosphite incorporated into the polymer and treated with the two types of sterilisation is rapidly oxidized in phosphate. Nevertheless, this oxidation is more important when using radiotreatment at 25 kGy. (orig.)

  5. Characterization of biomasses, concentrates, and permeates of dried powder of Kombucha fermentation of spinach (Amaranthus sp.) and broccoli (Brassica oleracea) with membrane microfiltration and freeze drying techniques for natural sources of folic acid

    Science.gov (United States)

    Nugraha, Tutun; Susilowati, Agustine; Aspiyanto, Lotulung, Puspa Dewi; Maryati, Yati

    2017-11-01

    Fermentation of spinach (Amaranthus sp) and Broccoli (Brassica oleracea) using Kombucha Culture has been shown to produce biomass that has the potential to become natural sources of folic acid. To produce the materials, following the fermentation, the biomass was filtered using membrane microfiltration (0.15 µm) at a pressure of 40 psia, at room temperature, yielding the concentrate and the permeate fractions. Following this step, freeze drying process was done on the biomass feeds, as well as on the concentrate and permeate fractions. For the freeze drying stage, the samples were frozen, and the condenser was kept at -50°C for 40 hours, while the pressure in the chamber was set at 200 Pa. Freeze drying results showed that the final products, have differences in compositions, as well as differences in the dominat monomers of folates. After water content was driven out, freeze drying increased the concentrations of folic acid in the dried products, and was found to be the highest in the concentrate fractions. Freeze drying has been shown to be capable of protecting the folates from heat and oxidative damages that typicaly occur with other types of drying. The final freeze dried concentrates of fermentation of spinach and broccoli were found to contain folic acid at 2531.88 µg/mL and 1626.94 µg/mL, total solids at 87.23% and 88.65 %, total sugar at 22.66 µg/mL and 25.13 µg/mL, total reducing sugar at 34.46 mg/mL and 15.22 mg/mL, as well as disolved protein concentrations at 0.93 mg/mL and 1.45 mg/mL. Liquid Chromatography Mass Spectometry (LC-MS) identification of the folates in the freeze dried concentrates of fermented spinach and broccoli was done using folic acid and glutamic acid standard solutions as the reference materials. The results showed the presence of folic acid and showed that the dominant monomers of molecules of folates with molecular weights of 441.44 Da. and 441.54 Da. for spinach and broccoli respectively. Moreover, the monomers of glutamic

  6. Helicopter In-flight Resuscitation with Freeze-dried Plasma of a Patient with a High-velocity Gunshot Wound to the Neck in Afghanistan - A Case Report.

    Science.gov (United States)

    Gellerfors, Mikael; Linde, Joacim; Gryth, Dan

    2015-10-01

    Massive hemorrhage with coagulopathy is one of the leading causes of preventable death in the battlefield. The development of freeze-dried plasma (FDP) allows for early treatment with coagulation-optimizing resuscitation fluid in the prehospital setting. This report describes the first prehospital use of FDP in a patient with carotid artery injury due to a high-velocity gunshot wound (HVGSW) to the neck. It also describes in-flight constitution and administration of FDP in a Medevac Helicopter. Early administration of FDP may contribute to hemodynamic stabilization and reduction in trauma-induced coagulopathy and acidosis. However, large-scale studies are needed to define the prehospital use of FDP and other blood products.

  7. The pharmaceutical applications of a biopolymer isolated from Trigonella foenum-graecum seeds: Focus on the freeze-dried matrix forming capacity

    Directory of Open Access Journals (Sweden)

    Sonia Iurian

    2017-12-01

    The FSM dispersions revealed shear thinning flow type. Based on colloidal dispersions' rheological properties, five FSM concentrations were taken forward to the lyophilization step. Completely dry and elegant tablets were obtained. Texture analysis indicated highly porous structures, confirmed by SEM analysis, which explain the fast disintegration properties. All the prepared tablets disintegrated in less than 47 s. The disintegration process was prolonged by the increase in FSM content, due to the high viscosity the polymer creates in aqueous media. FSM tablets presented longer disintegration times, as compared to gelatin tablets, but also higher crushing strength. Considering the fast disintegration and the high crushing strength, FSM is a good candidate as matrix forming agent for fast disintegrating dosage forms or other freeze-dried preparations.

  8. Freeze-dried allograft-mediated gene or protein delivery of growth and differentiation factor 5 reduces reconstructed murine flexor tendon adhesions

    DEFF Research Database (Denmark)

    Svensson, Sys Hasslund; Dadali, Tulin; Ulrich-Vinther, Michael

    2014-01-01

    reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and in vivo bioluminescent imaging. We then reconstructed flexor digitorum longus (FDL) tendons of the mouse hindlimb with allografts loaded with low and high doses of recombinant GDF-5 protein and r......Advances in allograft processing have opened new horizons for clinical adaptation of flexor tendon allografts as delivery scaffolds for antifibrotic therapeutics. Recombinant adeno-associated-virus (rAAV) gene delivery of the growth and differentiation factor 5 (GDF-5) has been previously...... associated with antifibrotic effects in a mouse model of flexor tendoplasty. In this study, we compared the effects of loading freeze-dried allografts with different doses of GDF-5 protein or rAAV-Gdf5 on flexor tendon healing and adhesions. We first optimized the protein and viral loading parameters using...

  9. A Comparison between Use of Spray and Freeze Drying Techniques for Preparation of Solid Self-Microemulsifying Formulation of Valsartan and In Vitro and In Vivo Evaluation

    Science.gov (United States)

    Singh, Sanjay Kumar; Vuddanda, Parameswara Rao; Singh, Sanjay; Srivastava, Anand Kumar

    2013-01-01

    The objective of the present study was to develop self micro emulsifying formulation (SMEF) of valsartan to improve its oral bioavailability. The formulations were screened on the basis of solubility, stability, emulsification efficiency, particle size and zeta potential. The optimized liquid SMEF contains valsartan (20% w/w), Capmul MCM C8 (16% w/w), Tween 80 (42.66% w/w) and PEG 400 (21.33% w/w) as drug, oil, surfactant and co-surfactant, respectively. Further, Liquid SMEF was adsorbed on Aerosol 200 by spray and freeze drying methods in the ratio of 2 : 1 and transformed into free flowing powder. Both the optimized liquid and solid SMEF had the particle size valsartan as compared to existing formulations with improved bioavailability. PMID:23971048

  10. Crystal phase evolution of TiO2 nanoparticles with reaction time in acidic solutions studied via freeze-drying method

    International Nuclear Information System (INIS)

    Shin, Hyunho; Jung, Hyun Suk; Hong, Kug Sun; Lee, Jung-Kun

    2005-01-01

    The crystal phase evolution of TiO 2 nanoparticles, during hydrolysis and condensation of titanium tetraisopropoxide, was quenched at various reaction times by a freeze-drying method, followed by various characterizations. Three types of solutions with different acid input times were studied: (1) addition in infinite time (no addition) (2) addition at 24h after the hydrolysis/condensation reaction started, and (3) addition from the beginning of the reaction. The acid-free solution yielded amorphous TiO 2 , which transformed to anatase very slowly. The acid input in 24h resulted in a fast transformation of amorphous to a metastable anatase having a highly distorted atomic arrangement: thereby its transformation to a more stable phase, rutile, was suitable. The acid addition from the beginning of the reaction yielded the formation of a relatively stable anatase from the hydrolysis seed, thereby the subsequent transformation to rutile was sluggish

  11. Anthocyanins standards (cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside isolation from freeze-dried açaí (Euterpe oleraceae Mart. by HPLC

    Directory of Open Access Journals (Sweden)

    Ana Cristina Miranda Senna Gouvêa

    2012-03-01

    Full Text Available Availability of analytical standards is a critical aspect in developing methods for quantitative analysis of anthocyanins. The anthocyanins cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were isolated from samples of freeze-dried açaí (Euterpe oleraceae Mart., which is a round and purple well-known palm fruit in Brazil, and then used as standards. The isolation of the anthocyanins was performed by High Performance Liquid Chromatography (HPLC, using an adapted six-channel selection valve. The identification of anthocyanin pigments in açaí was based on mass spectrometric data for molecular ions and MS-MS product ions and on previous published data. After the collection procedure, standards with a high purity grade were obtained and an external standard curve of each anthocyanin was plotted.

  12. Freeze-drying synthesis of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode material for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Qiao, Y.Q. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Wang, X.L., E-mail: wangxl@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Mai, Y.J.; Xia, X.H.; Zhang, J.; Gu, C.D. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Tu, J.P., E-mail: tujp@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C was synthesized by freeze-drying method. Black-Right-Pointing-Pointer A specific capacity of 105.6 mAh g{sup -1} can be obtained at 14.8 C. Black-Right-Pointing-Pointer 93.3 mAh g{sup -1} can be delivered at a higher current density of 29.6 C. Black-Right-Pointing-Pointer The Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C electrode shows a good cycling performance. - Abstract: Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C cathode material was synthesized by using a freeze-drying method followed by carbon-thermal reduction. This as-prepared material has a uniform particle size distribution and a well carbon coating on the surface of Li{sub 3}V{sub 2}(PO{sub 4}){sub 3} particles. The Li{sub 3}V{sub 2}(PO{sub 4}){sub 3}/C exhibits good electrochemical performance and cycling stability. Between 3.0 and 4.3 V, the composite delivered a reversible capacity of 125.2 mAh g{sup -1} at a charge-discharge rate of 1.48 C (1 C = 133 mA g{sup -1}) and without obviously capacity fading after 100 cycles. Even at 14.8 C and 29.6 C rates, it can still deliver discharge capacities of 105.6 mAh g{sup -1} and 93.3 mAh g{sup -1}, and the discharge capacities of 84.5 and 60.5 mAh g{sup -1} are sustained after 500 cycles, respectively.

  13. The effect of freeze-dried antibody concentrations on its stability in the presence of trehalose and hydroxypropyl-β-cyclodextrin: a Box-Behnken statistical design.

    Science.gov (United States)

    Faghihi, Homa; Khalili, Fatemeh; Amini, Mohsen; Vatanara, Alireza

    2017-09-01

    The present study aimed at preparation and optimization of stable freeze-dried immunoglobulin G (IgG) applying proper amount of antibody with efficient combination of trehalose and hydroxypropyl-β-cyclodextrin (HPβCD). Response surface methodology was employed through a three-factor, three-level Box-Behnken design. Amounts of IgG (X 1 ), trehalose (X 2 ) and HPβCD (X 3 ) were independent variables. Aggregation following process (Y 1 ), after one month at 45 °C (Y 2 ), upon two month at 45 °C (Y 3 ) and beta-sheet content of IgG (Y 4 ) were determined as dependent variables. Results were fitted to quadratic models (except for beta-sheet content), describing the inherent relationship between main factors. Optimized formulation composed of 55.85 mg IgG, 52.51 mg trehalose and 16.01 mg HPβCD was prepared. The calculated responses of the optimized formulation were as follows: Y 1  = 0.19%, Y 2  = 0.78%, Y 3  = 1.88% and Y 4  = 68.60%, respectively. The thermal analysis confirmed the amorphous nature of optimum formulation and the integrity of IgG was shown to be favorably preserved. Validation of the optimization study demonstrated high degree of prognostic ability. The DOE study successfully predicted the optimum values of antibody as well as stabilizers for desirable process and storage stabilization of freeze-dried IgG.

  14. Conformational and bioactivity analysis of insulin: freeze-drying TBA/water co-solvent system in the presence of surfactant and sugar.

    Science.gov (United States)

    Zhang, Yong; Deng, Yingjie; Wang, Xueli; Xu, Jinghua; Li, Zhengqiang

    2009-04-17

    Despite the extensive research into the freeze-drying of aqueous solutions of proteins, it remains unknown whether proteins can survive the lyophilization process in a water-organic co-solvent system and how the process and additives affect the structural stability and activity of the proteins. In the present study, a conformational analysis of insulin in the absence/presence of bile salt and trehalose was carried out, before and after freeze-drying of a tert-butyl alcohol (TBA)/water co-solvent system at volume ratios of TBA to water ranging from 50/50 to 0/100. The study involved the use of ultraviolet derivative and fluorescence spectroscopy, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy. Also the bioactivity of insulin was evaluated in vivo using the streptozotocin (STZ)-induced diabetic mice as an animal model. Initial investigations indicate that the extent of the structural change of insulin depends significantly both on the TBA content and on the concentration of additives, such as sodium deoxycholate, prior to lyophilization. This could be accounted for by the phase behavior properties of the TBA/water co-solvent system, surface denaturation together with the selective and/or forced dispersion of insulin during phase separation. Lyophilized insulin in the presence of bile salt and trehalose retained more of its bioactivity and native-like structure in the solid state compared with that in the absence of additives at various TBA/water ratios, although in all cases there was a major and reversible rearrangement of secondary structure after rehydration, except for insulin at 50% TBA (v/v). Furthermore, both lyophilization in non-eutectic systems and less structural changes in the formulation process lead to more bioactivity.

  15. Freeze-drying synthesis of Li3V2(PO4)3/C cathode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    Qiao, Y.Q.; Wang, X.L.; Mai, Y.J.; Xia, X.H.; Zhang, J.; Gu, C.D.; Tu, J.P.

    2012-01-01

    Highlights: ► Li 3 V 2 (PO 4 ) 3 /C was synthesized by freeze-drying method. ► A specific capacity of 105.6 mAh g −1 can be obtained at 14.8 C. ► 93.3 mAh g −1 can be delivered at a higher current density of 29.6 C. ► The Li 3 V 2 (PO 4 ) 3 /C electrode shows a good cycling performance. - Abstract: Li 3 V 2 (PO 4 ) 3 /C cathode material was synthesized by using a freeze-drying method followed by carbon-thermal reduction. This as-prepared material has a uniform particle size distribution and a well carbon coating on the surface of Li 3 V 2 (PO 4 ) 3 particles. The Li 3 V 2 (PO 4 ) 3 /C exhibits good electrochemical performance and cycling stability. Between 3.0 and 4.3 V, the composite delivered a reversible capacity of 125.2 mAh g −1 at a charge–discharge rate of 1.48 C (1 C = 133 mA g −1 ) and without obviously capacity fading after 100 cycles. Even at 14.8 C and 29.6 C rates, it can still deliver discharge capacities of 105.6 mAh g −1 and 93.3 mAh g −1 , and the discharge capacities of 84.5 and 60.5 mAh g −1 are sustained after 500 cycles, respectively.

  16. Pulmonary delivery of an inulin-stabilized influenza subunit vaccine prepared by spray-freeze drying induces systemic, mucosal humoral as well as cell-mediated immune responses in BALB/c mice

    NARCIS (Netherlands)

    Amorij, J-P.; Saluja, V.; Petersen, A.H.; Hinrichs, W.L.J.; Huckriede, A.; Frijlink, H.W.

    2007-01-01

    In this study pulmonary vaccination with a new influenza subunit vaccine powder was evaluated. Vaccine powder was produced by spray-freeze drying (SFD) using the oligosaccharide inulin as stabilizer. Immune responses after pulmonary vaccination of BALB/c mice with vaccine powder were determined and

  17. Freeze drying optimization of polymeric nanoparticles for ocular flurbiprofen delivery: effect of protectant agents and critical process parameters on long-term stability.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; Calpena Campmany, Ana Cristina; Egea Gras, María Antonia; Espina García, Marta; García López, María Luisa

    2017-04-01

    The stabilization of flurbiprofen loaded poly-ɛ-caprolactone nanoparticles (FB-PɛCL-NPs) for ocular delivery under accurate freeze-drying (FD) process provides the basis for a large-scale production and its commercial development. Optimization of the FD to improve long-term stability of ocular administration's FB-PɛCL-NPs. FB-PɛCL-NPs were prepared by solvent displacement method with poloxamer 188 (P188) as stabilizer. Freezing and primary drying (PD) were studied and optimized through freeze-thawing test and FD microscopy. Design of experiments was used to accurate secondary drying (SD) conditions and components concentration. Formulations were selected according to desired physicochemical properties. Furthermore, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to study interactions components. Optimized FB-PɛCL-NPs, stabilized with 3.5% (w/w) P188 and protected with 8% (w/w) poly(ethylene glycol), was submitted to precooling at +10 °C for 1 h, freezing at -50 °C for 4 h, PD at +5 °C and 0.140 mbar for 24 h and a SD at +45 °C during 10 h. These conditions showed 188.4 ± 1.3 nm, 0.087 ± 0.014, 85.5 ± 1.4%, 0.61 ± 0.12%, -16.4 ± 0.1 mV and 325 ± 7 mOsm/kg of average size, polydispersity index, entrapment efficiency, residual moisture, surface charge and osmolality, respectively. It performed a long-term stability >12 months. DSC and XRD spectra confirmed adequate chemical interaction between formulation components and showed a semi-crystalline state after FD. An optimal freeze dried ocular formulation was achieved. Evidently, the successful design of this promising colloidal system resulted from rational cooperation between a good formulation and the right conditions in the FD process.

  18. The influence of freeze drying and ϒ-irradiation in pre-clinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using D-(+-trehalose and polyethylene glycol

    Directory of Open Access Journals (Sweden)

    Ramos Yacasi GR

    2016-08-01

    Full Text Available Gladys Rosario Ramos Yacasi, María Luisa García López, Marta Espina García, Alexander Parra Coca, Ana Cristina Calpena Campmany Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, University of Barcelona, Barcelona, Spain Abstract: This study investigated the suspension of poly(ε-caprolactone nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5% and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350 and d-(+-trehalose (TRE. Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen’s egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE. IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over .30 days. This study concludes that both formulations meet the Goldman’s criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics

  19. The high water solubility of inclusion complex of taxifolin-γ-CD prepared and characterized by the emulsion solvent evaporation and the freeze drying combination method.

    Science.gov (United States)

    Zu, Yuangang; Wu, Weiwei; Zhao, Xiuhua; Li, Yong; Zhong, Chen; Zhang, Yin

    2014-12-30

    This study selected γ-cyclodextrin (γ-CD) as the inclusion material and prepared inclusion complex of taxifolin-γ-CD by the emulsion solvent evaporation and the freeze drying combination method to achieve the improvement of the solubility and oral bioavailability of taxifolin. We selected ethyl acetate as the oil phase, deionized water as the water phase. The taxifolin emulsion was prepared using adjustable speed homogenate machine in the process of this experiment, whose particle size was related to the concentration of taxifolin solution, the volume ratio of water phase to oil phase, the speed and time of homogenate. We knew through the single-factor test that, the optimum conditions were: the concentration of taxifolin solution was 40 mg/ml, the volume ratio of water phase to oil phase was 1.5, the speed of homogenate was 5,000 rpm, the homogenate time was 11 min. Taxifolin emulsion with a MPS of 142.5 nm was obtained under the optimum conditions, then the high-concentration taxifolin solution (3mg/ml) was obtained by the rotary evaporation process. Finally, the inclusion complex of taxifolin-γ-CD was prepared by vacuum freeze-dry. The characteristics of the inclusion complex of taxifolin-γ-CD were analyzed using SEM, FTIR, XRD, DSC, and TG. The FTIR results analyzed the interaction of taxifolin and γ-CD and determined the molecular structure of the inclusion complex of taxifolin-γ-CD. The analysis results of XRD, DSC and TG indicated that the inclusion complex of taxifolin-γ-CD was obtained and showed significantly different characteristics with taxifolin. In addition, dissolving capability test, antioxidant capacity test, solvent residue test were also carried out. The experimental datas showed that the solubility of inclusion complex of taxifolin-γ-CD at 25°C and 37°C were about 18.5 times and 19.8 times of raw taxifolin, the dissolution rate of inclusion complex of taxifolin-γ-CD were about 2.84 times of raw taxifolin, the bioavailability of

  20. Oral application of freeze-dried yeast particles expressing the PCV2b Cap protein on their surface induce protection to subsequent PCV2b challenge in vivo.

    Science.gov (United States)

    Patterson, Robert; Eley, Thomas; Browne, Christopher; Martineau, Henny M; Werling, Dirk

    2015-11-17

    Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a "proof of concept" vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNFα and IL-1β but higher concentrations of IFNα and IFNγ in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage. Copyright © 2015 The

  1. Radiosterilization dosimetry by electron-spin resonance spectroscopy. Cefotetan

    International Nuclear Information System (INIS)

    Basly, J.P.; Longy, I.; Bernard, M.

    1998-01-01

    As an alternative to heat and gas exposure sterilization, ionizing radiation is gaining interest as a sterilization process for medicinal products. Nevertheless, essentially for economic profit, unauthorized and uncontrolled use of radiation processes may be expected. In this context, it is necessary to find methods of distinguishing between irradiated and nonirradiated pharmaceuticals. In the absence of suitable detection methods, our attention was focused on electron-spin resonance (ESR) spectrometry. A third generation cephalosporin, cefotetan, was chosen as a model; this antibiotic is a potential candidate for radiation treatment due to its thermosensitivity. While the ESR spectra of a nonirradiated sample presents no signal, a nonsymmetrical signal, dependent on the irradiation dose, is found in irradiated samples. The number of free radicals was estimated by comparing the second integral from radiosterilized samples and a diphenylpicryl hydrazyl reference. Estimation of the number of free radicals gives 7x10 17 radicals g -1 at 20kGy (1.1x10 16 radicals in 15mg). From this result, the G-value (number of radicals (100eV) -1 ) could be estimated as 0.6. Decay of radicals upon storage were modeled using a bi-exponential function. The limit of detection of free radicals after irradiation at 25kGy is up to two years. This result agrees with those obtained on other cephalosporins. Aside from qualitative detection, ESR spectrometry can be used for dose estimation. Linear regression is applicable for doses lower than 20kGy. Since the radiation dose selected must always be based upon the bioburden of the products and the degree of sterility required (EN 552 and ANSI/AAMI/ISO 11137), 25kGy could no longer be accepted as a 'routine' dose for sterilizing a pharmaceutical. Doses in the 5-20kGy range could be investigated and linear regression appeared to be the least expensive route to follow. The best results for the integration of the curves were obtained with

  2. Polifenoles y Actividad Antioxidante del Fruto Liofilizado de Palma Naidi (Açai Colombiano (Euterpe oleracea Mart Polyphenols and Antioxidant Activity of the Freeze-Dried Palm Naidi (Colombian Açai (Euterpe oleracea Mart

    Directory of Open Access Journals (Sweden)

    Benjamín Alberto Rojano

    2011-12-01

    Full Text Available Euterpe oleracea es una palmera indígena autóctona de América del Sur. El fruto conocido como açaí en Brasil y palma naidi en Colombia, es de gran valor económico para los pueblos nativos. Para los análisis se usó una pulpa liofilizada, proveniente del Pacifico colombiano. Entre los muchos hallazgos, se presenta un alto porcentaje de minerales (6,94%, específicamente sodio, hierro y potasio. La palma naidi es rica en compuestos polifenólicos, tipo antocianinas (268,5 mg Cianidin-3-Glucosido/ 100 g de liofilizado donde el 95% de las antocianinas corresponden al Cianidin-3-Glucosido (255,1 mg/ 100 g de liofilizado y de otros compuestos fenólicos como los ácidos fenólicos: ferúlico (10,27 mg/100 g de liofilizado, caféico (7,06 mg/100 g de liofilizado, p-coumárico (2,81 mg/100 g de liofilizado y menor cantidad clorogénico 0,30 mg/100 g de liofilizado. Los polifenoles contribuyen a la capacidad antioxidante del naidi; medida por las técnicas ABTS, DPPH y FRAP y específicamente un valor ORAC (Hidrofílico (Oxygen Radical Absorbance Capacity de 98142,0 Micromol Tx/100 g de liofilizado; además un valor ORAC Lipofílico de 3194,1 Micromol Tx/ 100 g de liofilizado. Un valor ORAC total igual a 101336,1 Micromol Tx/ 100 g de liofilizado.Euterpe oleracea Mart is a native palm tree native of South America. The fruit known as açaí in Brazil and naidi palm in Colombia and is of great economic value to the native peoples. For the analysis was used freeze-dried pulp, from the Colombian Pacific. This fruit has a high percentage of minerals (6.94%, specifically sodium, potassium and iron. Naidi palm is rich in polyphenolic compounds, especially anthocyanins (268.5 mg cyanidin-3-glucoside per 100 g of freeze dried and phenolic acid as ferulic (10.27 mg/100 g of freeze dried , caffeic (7.06 mg/100 g of freeze dried, p-Coumaric (2.81 mg/100 g of freeze dried and fewer chlorogenic (0.30 mg/100 g of freeze dried; which provides high antioxidant

  3. Mechanical performance and thermal stability of glass fiber reinforced silica aerogel composites based on co-precursor method by freeze drying

    Science.gov (United States)

    Zhou, Ting; Cheng, Xudong; Pan, Yuelei; Li, Congcong; Gong, Lunlun; Zhang, Heping

    2018-04-01

    In order to maintain the integrity, glass fiber (GF) reinforced silica aerogel composites were synthesized using methltrimethoxysilane (MTMS) and water glass co-precursor by freeze drying method. The composites were characterized by scanning electron microscopy, Brunauer-Emmett-Teller analysis, uniaxial compressive test, three-point bending test, thermal conductivity analysis, contact angle test, TG-DSC analysis. It was found that the molar ratio of MTMS/water glass could significantly affect the properties of composites. The bulk density and thermal conductivity first decreased and then increased with the increasing molar ratio. The composites showed remarkable mechanical strength and flexibility compared with pure silica aerogel. Moreover, when the molar ratio is 1.8, the composites showed high specific surface area (870.9 m2/g), high contact angle (150°), great thermal stability (560 °C) and low thermal conductivity (0.0248 W/m·K). These outstanding properties indicate that GF/aerogels have broad prospects in the field of thermal insulation.

  4. Global Sensitivity Analysis as Good Modelling Practices tool for the identification of the most influential process parameters of the primary drying step during freeze-drying.

    Science.gov (United States)

    Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F C; Corver, Jos; Nopens, Ingmar; Gernaey, Krist V; De Beer, Thomas

    2018-02-01

    Pharmaceutical batch freeze-drying is commonly used to improve the stability of biological therapeutics. The primary drying step is regulated by the dynamic settings of the adaptable process variables, shelf temperature T s and chamber pressure P c . Mechanistic modelling of the primary drying step leads to the optimal dynamic combination of these adaptable process variables in function of time. According to Good Modelling Practices, a Global Sensitivity Analysis (GSA) is essential for appropriate model building. In this study, both a regression-based and variance-based GSA were conducted on a validated mechanistic primary drying model to estimate the impact of several model input parameters on two output variables, the product temperature at the sublimation front T i and the sublimation rate ṁ sub . T s was identified as most influential parameter on both T i and ṁ sub , followed by P c and the dried product mass transfer resistance α Rp for T i and ṁ sub , respectively. The GSA findings were experimentally validated for ṁ sub via a Design of Experiments (DoE) approach. The results indicated that GSA is a very useful tool for the evaluation of the impact of different process variables on the model outcome, leading to essential process knowledge, without the need for time-consuming experiments (e.g., DoE). Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Localization of tritiated 1-(2, 4-dichlorobenzyl)-1H-indazole-3-carboxylic acid ([3H] AF 1890) in rat testis using freeze-drying autoradiography

    International Nuclear Information System (INIS)

    Hilderbrandt-Stark, H.E.; Mills, J.W.; Fawcett, D.W.

    1982-01-01

    Tritiated 1-(2, 4-dichlorobenzyl)- 1 H-indazole-3-carboxylic acid ([ 3 H]AF 1890) was localized within rat testis using freeze-drying autoradiographic techniques. Ligated seminiferous tubule preparations were exposed in vitro to 80 microCi of [ 3 H]AF 1890 in the absence or presence of excess unlabeled AF 1890 for 30 min at 31 degrees C. Autoradiographs showed a generalized distribution of silver grains over the seminiferous epithelium, in the tubular lumen, and in the interstitial spaces. In addition, clusters of grains were concentrated over the seminiferous epithelium in regions of spermatid heads and tails and in the basal portion of the Sertoli cell cytoplasm, and over Leydig cells in the interstitial space. The generalized distribution was reduced and the grain clusters eliminated by incubation in an excess of unlabeled AF 1890. [ 3 H]inulin was used to assess the effectiveness of the tubular ligation because inulin does not normally penetrate the blood-testis barrier. This extracellular marker was not localized in the tubular lumen or in the seminiferous epithelium. Therefore, the labeling observed with [ 3 H]AF 1890 indicates that this compound crosses the blood-testis barrier

  6. Elimination of bicarbonate interference in the binding of U(VI) in mill-waters to freeze-dried Chlorella vulgaris

    International Nuclear Information System (INIS)

    Greene, B.; Henzl, M.T.; Hosea, J.M.; Darnall, D.W.

    1986-01-01

    Freeze-dried preparations of Chlorella vulgaris will accumulate U(Vl) from alkaline, bicarbonate-containing waters collected from uranium mill process streams, provided that the pH is pre-adjusted to between 4.0 and 6.0. Bicarbonate ion complexes the uranyl ion in these waters and seriously interferes with the binding of U(Vl) to the algal cells at pH values above 6.0. No binding of U(Vl) to the algae occurred at the natural pH of 8.0 when Chlorella vulgaris was suspended in untreated mull-waters containing up to 2.5 x 10 -4 M U(Vl). However, when the pH of these waters was lowered from 8.0 to near 5.0, with nitric acid, nearly quantitative binding of U(Vl) to the alga was achieved. Binding is rapid and largely unaffected by ions including Na + , Cl - , NO 3 - , - OAc, and SO 4 2- . Our results indicate that provided steps are taken to eliminate bicarbonate interference, such as adjustment of the pH to near 5.0, dried algal biomass could prove useful for the removal and recovery of U(Vl) from high carbonate-containing waters

  7. Comparison of blueberry powder produced via foam-mat freeze-drying versus spray-drying: evaluation of foam and powder properties.

    Science.gov (United States)

    Darniadi, Sandi; Ho, Peter; Murray, Brent S

    2018-03-01

    Blueberry juice powder was developed via foam-mat freeze-drying (FMFD) and spray-drying (SD) via addition of maltodextrin (MD) and whey protein isolate (WPI) at weight ratios of MD/WPI = 0.4 to 3.2 (with a fixed solids content of 5 wt% for FMFD and 10 wt% for SD). Feed rates of 180 and 360 mL h -1 were tested in SD. The objective was to evaluate the effect of the drying methods and carrier agents on the physical properties of the corresponding blueberry powders and reconstituted products. Ratios of MD/WPI = 0.4, 1.0 and 1.6 produced highly stable foams most suitable for FMFD. FMFD gave high yields and low bulk density powders with flake-like particles of large size that were also dark purple with high red values. SD gave low powder recoveries. The powders had higher bulk density and faster rehydration times, consisting of smooth, spherical and smaller particles than in FMFD powders. The SD powders were bright purple but less red than FMFD powders. Solubility was greater than 95% for both FMFD and SD powders. The FMFD method is a feasible method of producing blueberry juice powder and gives products retaining more characteristics of the original juice than SD. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  8. Characterization of critical physical and mechanical properties of freeze-dried grape powder for development of a clinical patient delivery system.

    Science.gov (United States)

    Hu, Daniel; Haware, Rahul V; Hamad, Mazen L; Morris, Kenneth R

    2013-02-01

    Grapes are hypothesized to be a "food medicine." Freeze-dried grape powder (FDGP) is being used to test clinical activity for a variety of applications and a reproducible and reliable delivery system was required. The FDGP was characterized using traditional physico-chemical methods to generate the data needed to identify its primary liability, i.e. moisture sorption. Above a threshold level of moisture content (~25% w/w, at RT), the material becomes both difficult to handle and exhibits significant degradation of several potentially clinically important chemical components (catechin, epicatechin, resveratrol). A moisture sorption isotherm was then used to tie the threshold to the exposure relative humidity above which this occurs. Kinetic uptake studies were used to estimate the maximum safe exposure time at a given humidity (a square root time dependence of moisture uptake was observed). Armed with this knowledge, a FDGP compact coated with a compression coat [100% bees wax or combinations of carnauba wax (70%) with HPC (30%) or Avicel(®) PH 102 (30%) or lactose monohydrate (30%)] was developed that will insure the shelf life of the material without the need for special handling for approximately more than 3 months.

  9. Water binding of proteins in the processing frankfurter-type sausages. Part. 1. Water-binding ability of freeze-dried meat fractions containing myofibrillar and stromal proteins.

    Science.gov (United States)

    Heinevetter, L; Gassmann, B; Kroll, J

    1987-01-01

    As soon as possible and 48 h after slaughter respectively, from both blade-bone muscle groups of cattle and pig carcasses the "thick pieces" were excised, extracted, and fractionated. Residues and precipitates from water and salt extracts resulted were freeze-dried, and an improved Baumann capillary suction apparatus was used to measure their water binding capacity (WBC) with and without addition of 2% sodium chloride and/or heating to 80 degrees C. With one exception the WBC results followed a relative pattern demonstrating the final residues (stromal proteins and leavings of myofibrillar proteins) binding the highest amount of added water, precipitates of dialysis (mainly containing myofibrillar proteins) a remarkable amount and powdered meats the least. As scanning electron micrographs confirmed, there were no fibrous structures in the precipitates resulted from dialysis of salt solutions (1.0 mol/1). Heating decreased the spontaneous water uptake of all fractions. Addition of sodium chloride had only a noticeable capillary-suction and swelling effect on unheated samples. Hence swelling of undissolved protein structures (extraction of myosin and possibly of actomyosin) is therefore not the only way for water binding in frankfurter-type sausages.

  10. Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

    Science.gov (United States)

    Fujita, Yukiko; Iwase, Hiroaki; Shida, Kenji; Liao, Jinsun; Fukui, Takehisa; Matsuda, Motohide

    2017-09-01

    Li2FeSiO4 is a promising cathode active material for lithium-ion batteries due to its high theoretical capacity. Spray-freezing/freeze-drying, a practical process reported for the synthesis of various ceramic powders, is applied to the synthesis of Li2FeSiO4/C composite powders and high-performance Li2FeSiO4/C composite powders are successfully synthesized by using starting solutions containing both Indian ink and glucose as carbon sources followed by heating. The synthesized composite powders have a unique structure, composed of Li2FeSiO4 nanoparticles coated with a thin carbon layer formed by the carbonization of glucose and carbon nanoparticles from Indian ink. The carbon layer enhances the electrochemical reactivity of the Li2FeSiO4, and the carbon nanoparticles play a role in the formation of electron-conducting paths in the cathode. The composite powders deliver an initial discharge capacity of 195 and 137 mAh g-1 at 0.1 C and 1 C, respectively, without further addition of conductive additive. The discharge capacity at 1 C is 72 mAh g-1 after the 100th cycle, corresponding to approximately 75% of the capacity at the 2nd cycle.

  11. Thermoelectrical and thermal analyses of copper(II) acetate monohydrate ZnO-matrix composite powder obtained by freeze-drying

    International Nuclear Information System (INIS)

    Bellini, Jusmar Valentin; Pineda, Edgardo Alfonso Gomez; Rocha, Raquel de Almeida; Ponzoni, Andre Luis de Lima; Paesano, Andrea

    2006-01-01

    The thermal history of freeze-dried mixtures of composite powders containing ZnO-matrix and (CH 3 COO) 2 Cu.H 2 O (copper(II) acetate monohydrate) was undertaken by thermal analysis (TA) coupled to thermoelectrical analysis (TEA). Experiments were carried out on compacted samples, under non-isothermal conditions, in air, up to 350 deg. C, by measuring the electrical resistance during heating, called thermoelectrical resistometry (TER), and by differential scanning calorimetry (DSC). Activation energy (E a ) for exothermal events related to the decomposition of (CH 3 COO) 2 Cu (copper(II) acetate, CuAc 2 ), observed within the range 225-325 deg. C, was estimated according to ASTM E 698 method. Values of E a equal to 154 and 155 kJ/mol were obtained by TER and DSC, respectively. TER showed that the thermal decomposition of CuAc 2 involves the liberation of electrons. Results also indicated that TER may be used as an alternative or complementary method for the study of the thermal decomposition mechanisms of transition metal(II) acetates

  12. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    Science.gov (United States)

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p < 0.01) in cells per scaffold mass vs. AD constructs. Collagen was ∼31% greater (p < 0.01) on FDAD compared to AD scaffolds not evident in microscopy of microsphere surfaces. Alternatively, AD scaffolds demonstrated a superior threefold increase in compressive strength over FDAD (12 vs. 4 MPa) with minimal degradation. Inclusion of FD spheres within the FDAD scaffolds allowed increased cellular activity through improved seeding, proliferation, and extracellular matrix production (as collagen), although mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  13. Complex formation of blueberry (Vaccinium angustifolium) anthocyanins during freeze-drying and its influence on their biological activity.

    Science.gov (United States)

    Correa-Betanzo, Julieta; Padmanabhan, Priya; Corredig, Milena; Subramanian, Jayasankar; Paliyath, Gopinadhan

    2015-03-25

    Biological activity of polyphenols is influenced by their uptake and is highly influenced by their interactions with the food matrix. This study evaluated the complex formation of blueberry polyphenols with fruit matrixes such as pectin and cellulose and their effect on the biological and antiproliferative properties of human colon cell lines HT-29 and CRL 1790. Free or complexed polyphenols were isolated by dialyzing aqueous or methanolic blueberry homogenates. Seven phenolic compounds and thirteen anthocyanins were identified in blueberry extracts. Blueberry extracts showed varying degrees of antioxidant and antiproliferative activities, as well as α-glucosidase activity. Fruit matrix containing cellulose and pectin, or purified polygalacturonic acid and cellulose, did not retain polyphenols and showed very low antioxidant or antiproliferative activities. These findings suggest that interactions between polyphenols and the food matrix may be more complex than a simple association and may play an important role in the bioefficacy of blueberry polyphenols.

  14. Use of a non-linear method for including the mass uncertainty of gravimetric standards and system measurement errors in the fitting of calibration curves for XRFA freeze-dried UNO3 standards

    International Nuclear Information System (INIS)

    Pickles, W.L.; McClure, J.W.; Howell, R.H.

    1978-05-01

    A sophisticated nonlinear multiparameter fitting program was used to produce a best fit calibration curve for the response of an x-ray fluorescence analyzer to uranium nitrate, freeze dried, 0.2% accurate, gravimetric standards. The program is based on unconstrained minimization subroutine, VA02A. The program considers the mass values of the gravimetric standards as parameters to be fit along with the normal calibration curve parameters. The fitting procedure weights with the system errors and the mass errors in a consistent way. The resulting best fit calibration curve parameters reflect the fact that the masses of the standard samples are measured quantities with a known error. Error estimates for the calibration curve parameters can be obtained from the curvature of the ''Chi-Squared Matrix'' or from error relaxation techniques. It was shown that nondispersive XRFA of 0.1 to 1 mg freeze-dried UNO 3 can have an accuracy of 0.2% in 1000 s

  15. In vivo gene transfer using pDNA/chitosan/chondroitin sulfate ternary complexes: influence of chondroitin sulfate on the stability of freeze-dried complexes and transgene expression in vivo.

    Science.gov (United States)

    Hagiwara, Kenji; Kishimoto, Satoko; Ishihara, Masayuki; Koyama, Yoshiyuki; Mazda, Osam; Sato, Toshinori

    2013-02-01

    Chitosan has been investigated as a promising nonviral vector. However, several problems still remain, such as a relatively low transfection efficiency and instability under physiological conditions. We previously demonstrated that a chondroitin sulfate (CS) coating enhanced the transfection efficiency and physicochemical stability of plasmid DNA (pDNA)/chitosan complexes in vitro. In the present study, the effects of coating pDNA/chitosan complexes with CS on the stability in freeze-dry rehydration processes and gene expression in vivo were investigated. Freeze-drying storage at -20 °C, 4 °C, or room temperature, freezing storage at -20 °C, or liquid storage at 4 °C or room temperature, were examined for preservation conditions of pDNA/chitosan/CS ternary complexes by a gel retardation assay, measurements of sizes and zeta potentials, and a luciferase assay. Moreover, to determine the transfection efficiency of the ternary complexes in vivo, suicide gene therapy was carried out in Huh-7-implanted mice using herpes simplex virus thymidine kinase coding pDNA and ganciclovir. The freeze-dried pDNA/chitosan/CS ternary complexes showed sufficient cell transfection ability in vitro and in vivo. In addition, ternary complexes were associated with a significant suppression of tumor growth and a histopathologically high anti-tumor effect by intratumoral injection to tumor-bearing mice. The CS coating enhanced the preservation stability of the pDNA/chitosan complexes after freeze-drying-rehydration and their transgene expression in vivo. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Heat Transfer Analysis of an Optimized, Flexible Holder System for Freeze-Drying in Dual Chamber Cartridges Using Different State-of-the-Art PAT Tools.

    Science.gov (United States)

    Korpus, Christoph; Pikal, Michael; Friess, Wolfgang

    2016-11-01

    The aim of this study was to determine the heat transfer characteristics of an optimized flexible holder device, using Tunable Diode Laser Absorption Spectroscopy, the Pressure Rise Test, and the gravimetric procedure. Two different controlled nucleation methods were tested, and an improved sublimation process, "preheated plate," was developed. Tunable Diode Laser Absorption Spectroscopy identified an initial sublimation burst phase. Accordingly, steady-state equations were adapted for the gravimetric procedure, to account for this initial non-steady-state period. The heat transfer coefficient, K DCC , describing the transfer from the holder to the DCC, was the only heat transfer coefficient showing a clear pressure dependence with values ranging from 3.81E-04 cal/(g·cm 2 ·K) at 40 mTorr to 7.38E-04 cal/(g·cm 2 ·K) at 200 mTorr. The heat transfer coefficient, K tot , reflecting the overall energy transfer via the holder, increased by around 24% from 40 to 200 mTorr. This resulted in a pressure-independent sublimation rate of around 42 ± 1.06 mg/h over the whole pressure range. Hence, this pressure-dependent increase in energy transfer completely compensated the decrease in driving force of sublimation. The "flexible holder" shows a substantially reduced impact of atypical radiation, improved drying homogeneity, and ultimately a better transferability of the freeze-drying cycle for process optimization. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  17. Microbial Diversity of a Camembert-Type Cheese Using Freeze-Dried Tibetan Kefir Coculture as Starter Culture by Culture-Dependent and Culture-Independent Methods

    Science.gov (United States)

    Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

    2014-01-01

    The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese. PMID:25360757

  18. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen's egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman's criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials.

  19. Preparation of liposomes containing zedoary turmeric oil using freeze-drying of liposomes via TBA/water cosolvent systems and evaluation of the bioavailability of the oil.

    Science.gov (United States)

    Yang, Zhiwen; Yu, Songlin; Fu, Dahua

    2010-02-01

    The purpose of this study was to enhance the absorption of zedoary turmeric oil (ZTO) in vivo and develop new formulations of a water-insoluble oily drug. This study described a method for preparing ZTO liposomes, which involved freeze-drying (FD) of liposomes with TBA/water cosolvent systems. The TBA/water cosolvent systems were used to investigate a feasible method of liposomes manufacture; the two factors, sugar/lipid mass ratio and TBA content (concentration), of the preparation process were evaluated in this study. The results showed that the addition of TBA content could significantly enhance the sublimation of ice resulting in short FD cycles time, and reduce the entrapment efficiency of liposomes. In addition, the residual TBA solvents levels were determined to be less than 0.37% under all optimum formulations and processing conditions. Several physical properties of liposomes were examined by H-600 transmission electron microscope (TEM) and zetamaster analyser system. The results revealed that the liposomes were smooth and spherical with an average particle size of 457 +/- 7.8 nm and the zeta potential was more than 3.65 Mv. The bioavailability of the liposomes was evaluated in rabbits, compared with the conventional self-emulsifying formulation for oral administration. Compared with the conventional self-emulsifying formulation, the plasma concentration-time profiles with improved sustained-release characteristics were achieved after oral administration of the liposomes with a bioavailability of 257.7% (a good strategy for improving the bioavailability of an oily drug). In conclusion, the present experimental findings clearly demonstrated the usefulness of ZTO liposome vesicles in improving therapeutic efficacy by enhancing oral bioavailability. Our study offered an alternative method for designing sustained-release preparations of oily drugs.

  20. Microbial diversity of a Camembert-type cheese using freeze-dried Tibetan kefir coculture as starter culture by culture-dependent and culture-independent methods.

    Directory of Open Access Journals (Sweden)

    Jun Mei

    Full Text Available The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR-denaturing gradient gel electrophoresis (DGGE analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates. Meanwhile, Kazachstania servazzii (51 isolates represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates. However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

  1. Effect of mangosteen peel extract combined with demineralized freezed-dried bovine bone xenograft on osteoblast and osteoclast formation in post tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2016-12-01

    Full Text Available Background: Tooth extraction, a common procedure in dentistry, can cause bone resorption during socket healing. Therefore, it is important to perform socket preservation procedure to maintain alveolar bone. Providing a combination of mangosteen peel extract with demineralized freezed-dried bovine bone xenograft (DFDBBX in tooth extraction socket was expected to accelerate alveol bone formation. Purpose: This study aims to determine the effect of mangosteen peel extract combined with DFDBBX introduced into the socket of post tooth extraction on the formation of osteoblasts and osteoclasts. Method: Twenty-eight (28 Cavia cobayas were divided into four groups. Extraction to the lower left incisor of Cavia cobaya was performed. The extraction socket was filled with 25 gram of PEG (group I as a control, active materials consisted of mangosteen peel extract and DFDBBX 0.5% (group II, active materials consisted of mangosteen peel extract and DFDBBX 1% (group III, and active materials consisted of mangosteen peel extract and DFDBBX 2% (group IV. After thirty days, those Cavia cobayas were sacrificed. By using HE on Histopatological examination, the number of osteoblasts and osteoclasts were measured by light microscope with 400 times of magnification. The statistical analysis was then performed using oneway Anova & TukeyHSD test. Result: The component active materials consisted of mangosteen peel extract and DFDBBX 2% had the most significant results related to the formation of osteoblasts and osteoclasts. Conclusion: Mangosteen peel extract combined with DFDBBX can increase osteoblasts and decrease osteoclasts in the socket of tooth extraction in Cavia cobaya. The combination of mangosteen peel extract and DFDBBX 2% is the most effective material in increasing osteoblast and decreasing osteoclast.

  2. Histologic Evaluation of Wound Healing After Ridge Preservation With Cortical, Cancellous, and Combined Cortico-Cancellous Freeze-Dried Bone Allograft: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Demetter, Randy S; Calahan, Blaine G; Mealey, Brian L

    2017-09-01

    Cortical and cancellous mineralized freeze-dried bone allografts (FDBA) are available for use in alveolar ridge preservation after tooth extraction. There are currently no data regarding use of a combination 50%/50% cortico-cancellous FDBA compared with a 100% cortical or 100% cancellous FDBA in ridge preservation. The primary objective of this study is to dimensionally and histologically evaluate healing after ridge preservation in non-molar sites using 50%/50% cortico-cancellous FDBA versus 100% cortical and 100% cancellous FDBA. Sixty-six patients requiring extraction of a non-molar tooth were enrolled and randomized into three groups to receive ridge preservation with the following: 1) 100% cortical FDBA; 2) 100% cancellous FDBA; or 3) 50%/50% cortico-cancellous FDBA. After 18 to 20 weeks of healing, a biopsy was harvested, and an implant was placed. The alveolar ridge was measured pre- and postoperatively to evaluate change in ridge height and width. Percentages of vital bone, residual graft, and connective tissue (CT)/other were determined via histomorphometric analysis. Histomorphometric analysis revealed no significant differences among groups regarding percentage of vital bone or CT/other. The 100% cortical FDBA group had significantly greater residual graft material (P = 0.04). Dimensional analysis revealed no significant between-group differences in any parameter measured. To the best knowledge of the authors, this study offers the first histologic evidence demonstrating no significant difference in vital bone formation or dimensional changes among 50%/50% cortico-cancellous FDBA, 100% cortical FDBA, and 100% cancellous FDBA when used in ridge preservation of non-molar tooth sites.

  3. Kinetics of the Degradation of Anthocyanins, Phenolic Acids and Flavonols During Heat Treatments of Freeze-Dried Sour Cherry Marasca Paste

    Directory of Open Access Journals (Sweden)

    Zoran Zorić

    2014-01-01

    Full Text Available The effect of heating temperature (80–120 °C and processing time (5–50 min on the stability of anthocyanins (cyanidin-3-glucosylrutinoside, cyanidin-3-rutinoside and cyanidin- 3-glucoside, quercetin-3-glucoside and phenolic acids (chlorogenic, neochlorogenic, p-coumaric and ferulic acids in freeze-dried Marasca sour cherry pastes was studied. The degradation rates of individual anthocyanins, quercetin-3-glucoside and phenolic acids followed the first order reaction kinetics. Cyanidin-3-glucoside was found to be the most unstable among the anthocyanins, together with p-coumaric and neochlorogenic acids among other phenols. Activation energies for anthocyanin degradation ranged from 42 (cyanidin-3-glucosylrutinoside to 55 kJ/mol (cyanidin-3-glucoside, and for other phenols from 8.12 (chlorogenic acid to 27 kJ/mol (neochlorogenic acid. By increasing the temperature from 80 to 120 °C, the reaction rate constant of cyanidin-3-glucosylrutinoside increased from 2.2·10–2 to 8.5·10–2 min–1, of p-coumaric acid from 1.12·10–2 to 2.5·10–2 min–1 and of quercetin-3-glucoside from 1.5·10–2 to 2.6·10–2 min–1. The obtained results demonstrate that at 80°C the half-life of anthocyanins ranges from 32.10 min for cyanidin-3-glucosylrutinoside to 45.69 min for cyanidin-3-rutinoside, and of other phenolic compounds from 43.39 for neochlorogenic acid to 66.99 min for chlorogenic acid. The results show that the heating temperature and duration affect the anthocyanins considerably more than the other phenols in terms of degradation.

  4. Evaluation of bioactive glass and demineralized freeze dried bone allograft in the treatment of periodontal intraosseous defects: A comparative clinico-radiographic study

    Directory of Open Access Journals (Sweden)

    Kishore Kumar Katuri

    2013-01-01

    Full Text Available Aim: The purpose of this study was to evaluate the efficacy of demineralized freeze dried bone allograft (DFDBA and bioactive glass by clinically and radiographically in periodontal intrabony defects for a period of 12 months. Materials and Methods: Ten systemically healthy patients diagnosed with chronic periodontitis, with radiographic evidence of at least a pair of contralateral vertical osseous defects were included in this study. Defect on one-side is treated with DFDBA and the other side with bioactive glass. Clinical and radiographic measurements were made at baseline 6 month and 12 month after the surgery. Results: Compared to baseline, the 12 month results indicated that both treatment modalities resulted in significant changes in all clinical parameters (gingival index, probing depth, clinical attachment level (CAL and radiographic parameters (bone fill; P < 0.001FNx01. However, sites treated with DFDBA exhibited statistically significantly more changes compared to the bioactive glass in probing depth reduction (2.5 ± 0.1 mm vs. 1.8 ± 0.1 mm CAL gain 2.4 ± 0.1 mm versus 1.7 ± 0.2 mm; ( P < 0.001FNx01. At 12 months, sites treated with bioactive glass exhibited 56.99% bone fill and 64.76% bone fill for DFDBA sites, which is statistically significant ( P < 0.05FNx01. Conclusion: After 12 months, there was a significant difference between the two materials with sites grafted with DFDBA showing better reduction in probing pocket depth, gain in CAL and a greater percentage of bone fill when compared to that of bioactive glass.

  5. Clinical application of radiation sterilized demineralized freeze dried bone allograft (DFDBA) and DFDBA combined with bovine periosteum membrane in periodontal defects

    International Nuclear Information System (INIS)

    Tantin R Dwijartini; Paramita Pandansari; Basril Abbas; Nazly Hilmy

    2008-01-01

    Full text: The objective of this report is to evaluate the effects of Radiation Sterilized Demineralized Freeze Dried Bone Allograft (DFDBA) and DFDBA combined with Bovine Periosteum Membrane (BPM) as well as BPM only in some cases of Periodontal Defects. BPM was used as a guided tissue regeneration. This study was carried out to 26 patients as follows : 10 cases for periodontal pocket using only DFDBA and DFDBA combined with BPM for 16 cases which consist of 10 cases of post extraction socket, 5 cases of gingival recession and one case of maxillary bone defect. DFDBA and periosteum membrane used were produced by BATAN Research Tissue Bank. Flap operation was done for all of the treatments, and followed by filling with DFDBA and/or DFDBA combined with periosteum membrane or BPM only. Evaluations were done up to 6 months. Parameters observed were the improvement of bone level, clinical attachment level, pocket depth and gingival margin location as well as increasing the thickness of maxillary bone. All of those evaluations were done by clinical observation and x-ray examination. Results obtained show that the improvement of clinical attachment level, reduces the pocket depth and increases bone density happened in all cases observed. It was also shows that BPM can be used as a guided tissue regeneration. No rejection could be observed in all of those cases. This study clearly indicated that DFDBA had an inductive effect on the formation of new bone and connective tissue. It can be concluded that DFDBA and Bovine Periosteum Membrane are promising to be used in treatment of the case of Periodontal Defects. (Author)

  6. Microbial diversity of a Camembert-type cheese using freeze-dried Tibetan kefir coculture as starter culture by culture-dependent and culture-independent methods.

    Science.gov (United States)

    Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

    2014-01-01

    The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

  7. A comparision of two types of decalcified freeze-dried bone allograft in treatment of dehiscence defects around implants in dogs

    Directory of Open Access Journals (Sweden)

    Ahmad Moghareh Abed

    2011-01-01

    Full Text Available Background: Decalcified freeze-dried bone allograft (DFDBA may have the potential to enhance bone formation around dental implants. Our aim in this study was the evaluation and comparison of two types of DFDBA in treatment of dehiscence defects around Euroteknika® implants in dogs. Methods : In this prospective clinical trial animal study, all mandibular premolars of three Iranian dogs were extracted. After 3 months of healing, fifteen SLA type Euroteknika® dental implants (Natea with 4.1mm diameter and 10mm length were placed in osteotomy sites with dehiscence defects of 5mm length, 4 mm width, and 3mm depth. Guided bone regeneration (GBR procedures were performed using Cenobone and collagen membrane for six implants, the other six implants received Dembone and collagen membrane and the final three implants received only collagen membrane. All implants were submerged. After 4 months of healing, implants were uncovered and stability (Implant Stability Quotient of all implants was measured. Then, block biopsies of each implant site were taken and processed for ground sectioning and histomorphometric analysis. The data was analyzed by ANOVA and Pearson tests. P value less than 0.05 was considered to be significant. Results: All implants osseointegrated after 4 months. The mean values of bone to implant contact for histomorphometric measurements of Cenobone, Denobone, and control groups were 77.36 ± 9.96%, 78.91 ± 11.9% and 71.56 ± 5.61% respectively, with no significant differences among the various treatment groups. The correlation of Implant Stability Quotient and histomorphometric techniques was 0.692. Conclusion: In treating of dehiscence defects with GBR technique in this study, adding DFDBA did not significantly enhance the percentages of bone-to-implant contact measurements; and Implant Stability Quotient Resonance Frequency Analysis appeared to be a precise technique.

  8. Effect of glass-forming biopreservatives on head group rotational dynamics in freeze-dried phospholipid bilayers: A 31P NMR study

    Science.gov (United States)

    Jain, P.; Sen, S.; Risbud, S. H.

    2009-07-01

    P31 NMR spectroscopy has been used to elucidate the role of glass-forming sugars in the preservation of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers. P31 wideline NMR spectra of freeze-dried pure DPPC, DPPC/trehalose, DPPC/glucose, and DPPC/hydroxyethyl starch (HES) mixtures collected in the temperature range of 25-80 °C have been simulated to obtain quantitative information about rotational dynamics and orientation of the lipid head groups in these media. In the case of pure DPPC, DPPC/glucose, and DPPC/HES, the gel-to-liquid crystalline phase transition of DPPC bilayer is characterized by a sudden increase in the rate of rotational diffusion of the PO4 head groups near 40 °C. The corresponding rotational jump frequency increases from a few kilohertz in the gel phase to at least several megahertz in the liquid crystalline phase. On the other hand, in the case of DPPC/trehalose mixture the temperature of this onset of rapid head group dynamics is increased by ˜10 °C. Trehalose reduces the lipid head group motions most effectively in the temperature range of T ≤50 °C relevant for biopreservation. Additionally, and possibly more importantly, trehalose is found to strongly restrict any change in the orientation of the diffusion axis of the PO4 head groups during the phase transformation. This unique ability of trehalose to maintain the dynamical and orientational rigidity of lipid head groups is likely to be responsible for its superior ability in biopreservation.

  9. FREEZE DRYING PROCESS: A REVIEW

    OpenAIRE

    Soham Shukla

    2011-01-01

    Among the various methods of drying, this article has mentioned only one most important method, “Freeze drying”. This method is mainly used for the drying of thermo labile materials. This method works on the principle of sublimation. This method is divided into 3 steps for its better understanding; these are Freezing, Primary drying, and secondary drying. There are many advantages and disadvantages of this method, but still this is the most useful drying method nowadays.

  10. Al2O3 Coated Concentration-Gradient Li[Ni0.73Co0.12Mn0.15]O2 Cathode Material by Freeze Drying for Long-Life Lithium Ion Batteries

    International Nuclear Information System (INIS)

    Wang, Jingpeng; Du, Chunyu; Yan, Chunqiu; He, Xiaoshu; Song, Bai; Yin, Geping; Zuo, Pengjian; Cheng, Xinqun

    2015-01-01

    Highlights: • Al 2 O 3 -coated concentration-gradient oxide is synthesized by a freeze drying method. • The effect of Al 2 O 3 -coating on concentration-gradient cathode is firstly studied. • Al 2 O 3 -coated sample exhibits high capacity and significantly enhanced cyclability. • Improved cyclability is ascribed to the effective protection of uniform Al 2 O 3 layer. - Abstract: In order to enhance the electrochemical performance of the high capacity layered oxide cathode with a Ni-rich core and a concentration-gradient shell (NRC-CGS), we use a freeze drying method to coat Al 2 O 3 layer onto the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material. The samples are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, charge-discharge measurements and electrochemical impedance spectroscopy. It is revealed that an amorphous Al 2 O 3 layer of about 5 nm in thickness is uniformly formed on the surface of NRC-CGS Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material by the freeze drying procedure. The freeze drying Al 2 O 3 -coated (FD-Al 2 O 3 -coated) sample demonstrates similar discharge capacity and significantly enhanced cycling performances, in comparison to the pristine and conventional heating drying Al 2 O 3 -coated (HD-Al 2 O 3 -coated) samples. The capacity decay rate of FD-Al 2 O 3 -coated Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material is 1.7% after 150 cycles at 55 °C, which is 9 and 12 times lower than that of the pristine and HD-Al 2 O 3 -coated samples. The superior electrochemical stability of the FD-Al 2 O 3 -coated sample is attributed to the synergistic protection of CGS and high-quality Al 2 O 3 coating that effectively protect the active material from electrolyte attack. The freeze drying process provides an effective method to prepare the high performance surface-coated electrode materials

  11. Formulation and evaluation of freeze-dried DOTMP kit for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP at the hospital radiopharmacy

    Energy Technology Data Exchange (ETDEWEB)

    Das, Tapas; Banerjee, Sharmila [Bhabha Atomic Research Centre, Radiopharmaceuticals Chemistry Section, Mumbai (India); Chakraborty, Sudipta [Bhabha Atomic Research Centre, Isotope Production and Applications Div., Mumbai (India); Sarma, Haladhar D. [Bhabha Atomic Research Centre, Radiation Biology and Health Sciences Div., Mumbai (India)

    2015-07-01

    The objective of the present work is to develop and evaluate freeze-dried DOTMP kit, which could be utilized for the convenient and single-step preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP, both of which have shown potential as alternative agents for metastatic bone pain palliation. Freeze-dried DOTMP kits, each comprising a lyophilized mixture of 20 mg DOTMP and 8.75 mg NaOH, were prepared. The kits were used for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP complexes. The agents were prepared by dissolving the lyophilized powder in 1 mL of normal saline and incubating with {sup 177}LuCl{sub 3} or {sup 153}SmCl{sub 3}, produced in-house, for 15 min at room temperature. Pharmacokinetic behavior and biological distribution of the agents were studied by carrying out biodistribution as well as scintigraphic studies in normal male Wistar rats. Shelf-life of the freeze-dried kits was also ascertained. Clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP complexes, comprising up to 3.7 GBq (100 mCi) of activity, were prepared with > 99% radiochemical purity using the freeze-dried kits. The complexes exhibited high in vitro stability when stored at room temperature. Biological studies showed selective skeletal accumulation and insignificant uptake of the radiotracers in any of the vital organs/tissue. The non-accumulated activity exhibited primary urinary clearance. The kits had a shelf-life of 2 years when stored at 4 C temperature. Freeze-dried DOTMP kits, suitable for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP, have been developed and the radiochemical and biological behaviors of the radiolabeled agents have been studied. The use of the kit at the hospital radiopharmacy is expected to make the preparations easy and convenient. This in turn will enable the widespread dissemination of these promising agents towards their application for regular use.

  12. Evolution of the Radio-sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares; Evolucion del Banco de Tejidos Radioesterilizados del Instituto Nacional de Investigaciones Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E.; Reyes F, M. L.; Luna Z, D., E-mail: esther.martinez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The Radio-sterilized Tissues Bank (RTB) of the Instituto Nacional de Investigaciones Nucleares (ININ) was established in 1997, as national project supported by the IAEA, who provided equipment, training and expert missions. In July of 1999, the Secretaria de Salud (Mexico) granted the sanitary license to the RTB. The first radio-sterilized tissue was the amnion. Later on, the process of frozen and lyophilized pig skin was development. Both tissue types are used as biological dressings in patient with burns, ulcers or on injuries difficult to heal, the amnion is also used for the damage treatment in the ocular surface. In 2003, the ININ improved the facilities of the RTB and in August of that same year the certification of the Quality Administration System was obtained under the standard ISO 9001:2000, at the present time ISO 9001:2008. The support of the IAEA granted to Mexico was of 1997-2004 and 2009-2012, by means of regional and inter regional projects where was obtained equipment and training mainly, for personal of the ININ and other institutions. With the last project supported by the IAEA, two very important documents were generated for the tissues bank of Argentina, Brazil, Colombia, Costa Rica, Cuba, Ecuador, El Salvador, Mexico, Peru, Uruguay and Venezuela, strengthening the interaction among these countries. To offer more radio-sterilized tissues to the medical community, in June of 2007 the RTB signed and agreement with the Secretaria de Salud of the Mexico State by means of the Centro Estatal de Transplantes del Estado de Mexico, for the process of muscle-skeletal tissue, skin and amnion. At present, besides amnion and pig skin, in the RTB there is in existence powdered and chips bone; concluding the validation stage the human skin process is. As a social function of the ININ, the RTB has contributed to the health improvement of patients of more than 50 hospital institutions, mainly those that assist to patient of low resources in different cities of

  13. PENGGUNAAN BERBAGAI JENIS BAHAN PELINDUNG UNTUK MEMPERTAHANKAN VIABILITAS BAKTERI ASAM LAKTAT YANG DI ISOLASI DARI AIR SUSU IBU PADA PROSES PENGERINGAN BEKU [Utilization of various cryogenic agents during freeze drying to Maintain the viability of Lactic Acid Bacteria Isolated from breast milk

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Puspawati1*

    2010-06-01

    Full Text Available Lactic acid bacteria are the most important bacteria having potential as probiotic. The objectives of the present study were to examine the growth of Lactic Acid Bacteria, identify the Lactic Acid Bacteria capable of surviving and evaluate the best cryogenic agents that protect the viability of Lactic Acid Bacteria during freeze drying. Four cryogenic agents, i.e. sucrose, lactose, skim milk and maltodextrin, were used in freeze drying of three species of Lactic Acid Bacteria, i.e. Pediococcus pentosaceus A16, Lactobacillus brevis A17 and Lactobacillus rhamnosus R21 isolated from breast milk. Evaluation included viability before and after freeze drying, survival of freeze dried culture in 0.5 % bile salt and low pH for 5 hours. The result showed that three of cryogenics, i.e. sucrose, lactose and skim milk improved the viability of freeze dried of all lactobacilli, except maltodextrin that did not give protection to L. rhamnosus R21. Evaluation on the survival of LAB in 0.5 % bile salt showed that cryogenic agents improved the survival rate of all Lactic Acid Bacteria during freeze drying. The cryogenic also improved the survival rate of LAB at low pH, with the best protection given by skim milk on L. rhamnosus R21.

  14. Rapid diagnosis of avian influenza virus in wild birds: Use of a portable rRT-PCR and freeze-dried reagents in the field

    Science.gov (United States)

    Takekawa, John Y.; Hill, N.J.; Schultz, A.K.; Iverson, S.A.; Cardona, C.J.; Boyce, W.M.; Dudley, J.P.

    2011-01-01

    Wild birds have been implicated in the spread of highly pathogenic avian influenza (HPAI) of the H5N1 subtype, prompting surveillance along migratory flyways. Sampling of wild birds for avian influenza virus (AIV) is often conducted in remote regions, but results are often delayed because of the need to transport samples to a laboratory equipped for molecular testing. Real-time reverse transcriptase polymerase chain reaction (rRT-PCR) is a molecular technique that offers one of the most accurate and sensitive methods for diagnosis of AIV. The previously strict lab protocols needed for rRT-PCR are now being adapted for the field. Development of freeze-dried (lyophilized) reagents that do not require cold chain, with sensitivity at the level of wet reagents has brought on-site remote testing to a practical goal. Here we present a method for the rapid diagnosis of AIV in wild birds using an rRT-PCR unit (Ruggedized Advanced Pathogen Identification Device or RAPID, Idaho Technologies, Salt Lake City, UT) that employs lyophilized reagents (Influenza A Target 1 Taqman; ASAY-ASY-0109, Idaho Technologies). The reagents contain all of the necessary components for testing at appropriate concentrations in a single tube: primers, probes, enzymes, buffers and internal positive controls, eliminating errors associated with improper storage or handling of wet reagents. The portable unit performs a screen for Influenza A by targeting the matrix gene and yields results in 2-3 hours. Genetic subtyping is also possible with H5 and H7 primer sets that target the hemagglutinin gene. The system is suitable for use on cloacal and oropharyngeal samples collected from wild birds, as demonstrated here on the migratory shorebird species, the western sandpiper (Calidrus mauri) captured in Northern California. Animal handling followed protocols approved by the Animal Care and Use Committee of the U.S. Geological Survey Western Ecological Research Center and permits of the U.S. Geological Survey

  15. Compatibility of polymeric materials with the radiosterilization of disposable medical products

    International Nuclear Information System (INIS)

    Gonzalez, M.E.

    1990-01-01

    The semiindustrial plant of irradiation located at the Atomic Center of Ezeiza entered into operation 20 years ago. This plant has a nominal activity of 3.7 x 10 16 Bq (10 6 Ci) and is presently operating with 1.78 x 10 16 Bq (4.8 x 10 5 Ci). The facility allows working in pilot plant scale for the study of industrial applications and also performs commercial services, the most important of which considering its volume, economic significance and social function is the radiosterilization of disposable medical products. Approximately 29,000 m 3 have been processed in this period, most of the materials being polymers, as component parts of the products as well as packaging. To validate the process of radiosterilization the materials compatibility with ionizing radiation must be known. In the department that operates the irradiation plant, the polymer laboratory is involved in the development of industrial applications and also in the subject of compatibility of polymers with radiosterilization. The laboratory gives advice on request about selection of materials as well as relevant information for the evaluation of radiation resistance and stability, including exposition doses for the samples and mechanical, physical or chemical tests according to the kind of product. In many occasions this laboratory has had to undertake these tests because local manufacturers of medical products not always have adequate facilities for quality control. Among mechanical tests the area under the stress-strain curve as a measure of the strain the material can undergo without fracture is perhaps the best for the evaluation of degradation. Among physical properties it is important to evaluate discoloration, usual in plastics irradiation, and concerning chemical tests the detection of migration of components from the polymer proves important in some cases. Although the irradiator cannot assume any responsibility concerning compatibility, local experience has shown the importance of having a

  16. Radiosterilization process control in plants using electron accelerators; Kontrola procesu sterylizacji radiacyjnej w stacjach korzystajacych z akceleratorow elektronow

    Energy Technology Data Exchange (ETDEWEB)

    Stuglik, Z [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Electron beam parameters deciding the irradiation dose in radiosterilization plants should be continuously controlled during the process. Dosimetric procedure suitable to irradiated material and dose range should be chosen. The practical advice and directions in this subject have been done. 7 refs.

  17. Review of the Code of Practice for the Radiosterilization of Medical Products

    International Nuclear Information System (INIS)

    Kallings, L.O.

    1967-01-01

    The background of the IAEA recommendations for a Code of Practice is outlined. The possibility of laying down broad safety margins based on scientific foresight and detailed advanced planning will serve to guide the rapidly accelerating acceptance of radiosterilization by industry, especially in those firms producing supplies for use in medicine and surgery. Production control should be attuned to the scientific and technological advances, and it is becoming clear that the focus of control should be moved away from sterility testing of the finished products to hygienic and sterile operations during the manufacturing operations themselves. The contamination of the product before sterilization should already have been kept to a minimum, and this pre-sterilization level of contamination should be regularly recorded using bacteriological tests. The choice of dosage should be based on average pre-sterilization counts and the inactivation factors found desirable for die intended use of the product. On commissioning, or whenever an existing process is altered, the efficiency of the irradiation facility must be tested using microbiological reference standards. The margin of safety should be checked by using deliberately contaminated articles. However, the backbone of the control procedures must still be dosimetry. The preparation of a Code of Practice for the Radiosterilization of Medical Products will constitute a challenge to operators working with other sterilizing procedures. (author)

  18. Freeze-drying synthesis of three-dimensional porous LiFePO{sub 4} modified with well-dispersed nitrogen-doped carbon nanotubes for high-performance lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Tu, Xiaofeng; Zhou, Yingke, E-mail: zhouyk888@hotmail.com; Song, Yijie

    2017-04-01

    Highlights: • Three-dimensional porous LiFePO{sub 4}/N-CNTs is synthesized by a freeze-drying method. • The N-CNTs conductive network enhances the electron transport within the LiFePO{sub 4} electrode. • The continuous pores accelerate the diffusion of lithium ions. • LiFePO{sub 4}/N-CNTs demonstrates an excellent electrochemical Li-insertion performance. - Abstract: The three-dimensional porous LiFePO{sub 4} modified with uniformly dispersed nitrogen-doped carbon nanotubes has been successfully prepared by a freeze-drying method. The morphology and structure of the porous composites are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performances are evaluated using the constant current charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The nitrogen-doped carbon nanotubes are uniformly dispersed inside the porous LiFePO{sub 4} to construct a superior three-dimensional conductive network, which remarkably increases the electronic conductivity and accelerates the diffusion of lithium ion. The porous composite displays high specific capacity, good rate capability and excellent cycling stability, rendering it a promising positive electrode material for high-performance lithium-ion batteries.

  19. Effect of freeze-drying and self-ignition process on the microstructural and electrochemical properties of Li{sub 4}Ti{sub 5}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Jamin, Claire [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Traina, Karl [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Eskenazi, David [Chemical Engineering Laboratory, Department of Applied Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Krins, Natacha; Cloots, Rudi; Vertruyen, Bénédicte [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Boschini, Frédéric, E-mail: frederic.boschini@ulg.ac.be [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium)

    2013-11-15

    Graphical abstract: - Highlights: • Li{sub 4}Ti{sub 5}O{sub 12} is prepared by a method involving self-ignition of a freeze-dried gel. • Addition of NH{sub 4}NO{sub 3} modifies the self-ignition propagation mode. • Well-crystallized Li{sub 4}Ti{sub 5}O{sub 12} phase is obtained after only 2 h at 800 °C. • Li{sub 4}Ti{sub 5}O{sub 12} powder has 161 mAh g{sup −1} capacity and good retention at C/4 rate. - Abstract: Crystalline Li{sub 4}Ti{sub 5}O{sub 12} is synthesized by a method involving the freeze-drying and self-ignition of a gel prepared from titanium isopropoxide, lithium nitrate and hydroxypropylmethylcellulose (HPMC). This synthesis route yields crystalline Li{sub 4}Ti{sub 5}O{sub 12} particles after calcination at 800 °C for 2 h. In an alternative route, addition of ammonium nitrate shifts the self-ignition mode from wave-like propagation to simultaneous. Powders with different microstructures are thereby obtained. Electrochemical characterization shows that the best results for Li{sup +} intercalation/desintercalation are obtained for the powder prepared without ammonium nitrate addition. These results highlight the necessity for a control of the self-ignition mode to obtain adequate properties.

  20. Freeze-drying synthesis of three-dimensional porous LiFePO4 modified with well-dispersed nitrogen-doped carbon nanotubes for high-performance lithium-ion batteries

    International Nuclear Information System (INIS)

    Tu, Xiaofeng; Zhou, Yingke; Song, Yijie

    2017-01-01

    Highlights: • Three-dimensional porous LiFePO 4 /N-CNTs is synthesized by a freeze-drying method. • The N-CNTs conductive network enhances the electron transport within the LiFePO 4 electrode. • The continuous pores accelerate the diffusion of lithium ions. • LiFePO 4 /N-CNTs demonstrates an excellent electrochemical Li-insertion performance. - Abstract: The three-dimensional porous LiFePO 4 modified with uniformly dispersed nitrogen-doped carbon nanotubes has been successfully prepared by a freeze-drying method. The morphology and structure of the porous composites are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performances are evaluated using the constant current charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The nitrogen-doped carbon nanotubes are uniformly dispersed inside the porous LiFePO 4 to construct a superior three-dimensional conductive network, which remarkably increases the electronic conductivity and accelerates the diffusion of lithium ion. The porous composite displays high specific capacity, good rate capability and excellent cycling stability, rendering it a promising positive electrode material for high-performance lithium-ion batteries.

  1. Characterization of phenolics, glucosinolates and antioxidant activity of beverages based on apple juice with addition of frozen and freeze-dried curly kale leaves (Brassica oleracea L. var. acephala L.).

    Science.gov (United States)

    Biegańska-Marecik, Róża; Radziejewska-Kubzdela, Elżbieta; Marecik, Roman

    2017-09-01

    The aim of this study was to determine the polyphenols, glucosinolates and ascorbic acid content as well as antioxidant activity of beverages on the base of apple juice with addition of frozen and freeze-dried curly kale leaves. Upon enrichment with frozen (13%) and freeze-dried curly kale (3%), the naturally cloudy apple juice was characterized by an increase in phenolic compounds by 2.7 and 3.3-times, accordingly. The antioxidant activity of beverages with the addition of curly kale ranged from 6.6 to 9.4μmol Trolox/mL. The obtained beverages were characterized glucosinolates content at 117.6-167.6mg/L and ascorbic acid content at 4,1-31,9mg/L. The results of sensory evaluation of colour, taste and consistency of apple juice and beverages with the addition of kale did not differ significantly prior to pasteurization (P≤0.05), whereas after the pasteurization the evaluated factors decreased significantly. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Development of a computational system for management of risks in radiosterilization processes of biological tissues

    International Nuclear Information System (INIS)

    Montoya, Cynara Viterbo

    2009-01-01

    Risk management can be understood to be a systematic management which aims to identify record and control the risks of a process. Applying risk management becomes a complex activity, due to the variety of professionals involved. In order to execute risk management the following are requirements of paramount importance: the experience, discernment and judgment of a multidisciplinary team, guided by means of quality tools, so as to provide standardization in the process of investigating the cause and effects of risks and dynamism in obtaining the objective desired, i.e. the reduction and control of the risk. This work aims to develop a computational system of risk management (software) which makes it feasible to diagnose the risks of the processes of radiosterilization of biological tissues. The methodology adopted was action-research, according to which the researcher performs an active role in the establishment of the problems found, in the follow-up and in the evaluation of the actions taken owing to the problems. The scenario of this action-research was the Laboratory of Biological Tissues (LTB) in the Radiation Technology Center IPEN/CNEN-SP - Sao Paulo/Brazil. The software developed was executed in PHP and Flash/MySQL language, the server (hosting), the software is available on the Internet (www.vcrisk.com.br), which the user can access from anywhere by means of the login/access password previously sent by email to the team responsible for the tissue to be analyzed. The software presents friendly navigability whereby the user is directed step-by-step in the process of investigating the risk up to the means of reducing it. The software 'makes' the user comply with the term and present the effectiveness of the actions taken to reduce the risk. Applying this system provided the organization (LTB/CTR/IPEN) with dynamic communication, effective between the members of the multidisciplinary team: a) in decision-making; b) in lessons learned; c) in knowing the new risk

  3. Eletrólise de resíduos poluidores: I - Efluente de uma indústria liofilizadora de condimentos Electrolysis of polluting wastes: I - Wastewater from a seasoning freeze-drying industry

    Directory of Open Access Journals (Sweden)

    Dejanira F. de Angelis

    1998-02-01

    Full Text Available Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD and chemical (COD oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD showed that the biodegradability of the wastewater was significantly increased; furthermore, Fe2+ ions liberated by the electrodes cause microorganisms to die and, when oxidised to Fe3+, contribute for the flocculation and sedimentation of solid residues.

  4. Freeze-drying synthesis of three-dimensional porous LiFePO4 modified with well-dispersed nitrogen-doped carbon nanotubes for high-performance lithium-ion batteries

    Science.gov (United States)

    Tu, Xiaofeng; Zhou, Yingke; Song, Yijie

    2017-04-01

    The three-dimensional porous LiFePO4 modified with uniformly dispersed nitrogen-doped carbon nanotubes has been successfully prepared by a freeze-drying method. The morphology and structure of the porous composites are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performances are evaluated using the constant current charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The nitrogen-doped carbon nanotubes are uniformly dispersed inside the porous LiFePO4 to construct a superior three-dimensional conductive network, which remarkably increases the electronic conductivity and accelerates the diffusion of lithium ion. The porous composite displays high specific capacity, good rate capability and excellent cycling stability, rendering it a promising positive electrode material for high-performance lithium-ion batteries.

  5. PENGARUH DEFATTING, FREKUENSI PENCUCIAN DAN JENIS DRYOPROTECTANT TERHADAP MUTU TEPUNG SURIMI IKAN LELE KERING BEKU [Effect of Defatting, Washing Cycle and Dryoprotectant Type on the Quality of Freeze Dried Catfish Surimi Powder

    Directory of Open Access Journals (Sweden)

    Wahyu Ramadhan*

    2014-06-01

    Full Text Available Freeze dried surimi powder is a surimi type processed by freeze drying. To utilize oversized catfish and to reduce surimi handling cost, oversized catfish has been used as raw material of surimi powder. The study aimed to determine the effect of defatting (NaHCO3 concentration and soaking duration, washingcycle,and dryoprotectant type on catfish surimi, as well as quality differences between surimi powder and wet surimi. With regard to defatting step, soaking in NaHCO3 0.75% for 10 minutes was found as the best treatment and resulting in a fat content of 1.52%. Moreover, one time of washing cycle was found as the most appropriate procedure to obtain a superior quality of surimi with whiteness value 57.21%, water holding capacity 73.28%, salts soluble protein 7.17%, pH 6.69, and gel strength 482.3 g/cm2, folding value of 4.84, and teeth cutting value of 8.26. Trehalose 6% was the most suitable dryoprotectant resulting in surimi powder with water holding capacity of 8.01 mL/g, gel strength 826.3 g/cm2, salt soluble protein 18.98%, density 4.06 mL/10 g, rehydration capacity 3.81, emulsion capacity 69.3%, emulsion stability 59.3%, foaming capacity 25.33% and foaming stability 9.40%. The microstructure profile of surimi powder added with trehalose had more compact tissues, without any damage and clots, than that treated with other dryoprotectants. However, surimi powder still had lower protein content than wet surimi, and lower physical and chemical properties, particularly in its teeth cutting and folding characteristics.

  6. Radiopharmaceutical development of a freeze-dried kit formulation for the preparation of [99mTc-EDDA-HYNIC-D-Phe1, Tyr3]-octreotide, a somatostatin analog for tumor diagnosis.

    Science.gov (United States)

    Guggenberg, Elisabeth Von; Mikolajczak, Renata; Janota, Barbara; Riccabona, Georg; Decristoforo, Clemens

    2004-10-01

    [(99m)Tc-EDDA-HYNIC-D-Phe(1),Tyr(3)]-Octreotide ((99m)Tc-EDDA/HYNIC-TOC) is a promising new radiopharmaceutical with the potential to replace [(111)In-DTPA-D-Phe(1)]-Octreotide ((111)In-DTPA-OCT) as the radiopharmaceutical for somatostatin receptor scintigraphy due to the advantage of improved image quality, lower radiation dose for the patient, and daily availability. Here we describe the development of a freeze-dried kit formulation based on the Tricine/EDDA exchange labeling approach for the preparation of this radiopharmaceutical in a clinical setting. Three parameters were of major importance to achieve a suitable formulation with a radiochemical purity (RCP) >90%: addition of bulking agent, the pH of the freeze-drying solution, and the content of stannous chloride. The final formulation consisted of 20 mg Tricine, 10 mg EDDA, 50 mg Mannitol, 20 microg SnCl(2). 2H(2)O, and 20 microg [HYNIC-D-Phe(1), Tyr(3)]-Octreotide (HYNIC-TOC). Radiolabeling was performed by addition of 0.2 M Na(2)HPO(4) to adjust the pH to 6-7, followed by 0.5-2 GBq (99m)Tc sodium pertechnetate, in a total volume of 2 mL and incubation for 10 min in a boiling water bath. Mean RCP values of 10 batches showed values >90% over a storage period of up to 1 year, a high stability up to 24 h of the final preparation, and retained biological activity. The developed kit formulation forms the basis for further clinical evaluation of this promising new radiopharmaceutical. Copyright 2004 Wiley-Liss, Inc. and the American Pharmacists Association

  7. Assessment of changes in chemical structure of vitamin K (K-thrombyl), due to γ-radiosterilization

    International Nuclear Information System (INIS)

    Ossman, A.R.E.

    1986-01-01

    The present application of radiosterilization is confined primarily to those materials which cannot be heat sterilized. This study involves: a) Finding the lowest possible dose that will produce a sterile product. b) Comparison of the physical and chemical properties of the irradiated products of different dose levels with those sterilized by other stated method (pharmacopoeial or currently applied methods), and of control composed of untreated ampoules. (orig.) [de

  8. Preliminary field studies on the control of the red palm weevil, Rhynchophorus ferrugineus Oliv., using radiosterilized males

    International Nuclear Information System (INIS)

    Rahalkar, G.W.; Harwalkar, M.R.; Rananavare, H.D.

    1977-01-01

    Feasibility of using sterile male release method for the control of red palm weevil, Rhynchophorus ferrungineus Oliv., a serious pest of coconut and other cultivated palms in India was investigated. A total of over 5000 radiosterilized males were released in an 800 acre coconut plantation near Kayangulam in Kerala. Data on the fertility pattern of native females is presented and the factors affecting the efficacy of sterile male release for control of this insect are discussed. (author)

  9. Chromosome studies on bone marrow cells of chinese hamsters fed a radiosterilized diet

    International Nuclear Information System (INIS)

    Renner, H.W.

    1977-01-01

    Metaphase preparations of chromosomes from bone marrow cells of Chinese hamsters were examined for mutagenic effects following the feeding of a radiosterilized diet. No increase in the incidence of structural chromosomal aberrations was observed. As far as numerical aberrations were concerned, the proportion of cells with polyploidy increased to between 4 to 5 times the control level, irrespective of the moisture content of the diet. This polyploidy effect occurred very early, being detectable within 24 h, if the diet fed had been irradiated with an absorbed dose of 4.5x10 6 rad. The incidence of polyploidy remained below 0.5%, however, nor did it rise with higher radiation doses. When the feeding of the irradiated diet was stopped, the proportion of polyploid cells returned to the control level within a maximum of 6 weeks. If the diet was stored (initially) for 6 weeks following irradiation before being fed to the animals no increase in the number of polyploid cells was noted. These results are not interpreted as a mutagenic effect of the irradiated diet. (author)

  10. Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

    Science.gov (United States)

    Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

    2013-01-01

    Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

  11. Pulmonary immunization of chickens using non-adjuvanted spray-freeze dried whole inactivated virus vaccine completely protects against highly pathogenic H5N1 avian influenza virus

    NARCIS (Netherlands)

    Peeters, Ben; Tonnis, Wouter F.; Murugappan, Senthil; Rottier, Peter; Koch, Guus; Frijlink, Henderik W.; Huckriede, Anke; Hinrichs, Wouter L. J.

    2014-01-01

    Highly pathogenic avian influenza (HPAI) H5N1 virus is a major threat to public health as well as to the global poultry industry. Most fatal human infections are caused by contact with infected poultry. Therefore, preventing the virus from entering the poultry population is a priority. This is,

  12. Through-vial impedance spectroscopy of the mechanisms of annealing in the freeze-drying of maltodextrin: the impact of annealing hold time and temperature on the primary drying rate.

    Science.gov (United States)

    Smith, Geoff; Arshad, Muhammad Sohail; Polygalov, Eugene; Ermolina, Irina

    2014-06-01

    The study aims to investigate the impact of annealing hold time and temperature on the primary drying rate/duration of a 10% (w/v) solution of maltodextrin with an emphasis on how the mechanisms of annealing might be understood from the in-vial measurements of the ice crystal growth and the glass transition. The electrical impedance of the solution within a modified glass vial was recorded between 10 and 10(6) Hz during freeze-drying cycles with varying annealing hold times (1-5 h) and temperatures. Primary drying times decreased by 7%, 27% and 34% (1.1, 4.3 and 5.5 h) with the inclusion of an annealing step at temperatures of -15°C, -10°C and -5°C, respectively. The glass transition was recorded at approximately -16°C during the re-heating and re-cooling steps, which is close to the glass transition (Tg ') reported for 10% (w/v) maltodextrin and therefore indicates that a maximum freeze concentration (∼86%, w/w, from the Gordon-Taylor equation) was achieved during first freezing, with no further ice being formed on annealing. This observation, coupled to the decrease in electrical resistance that was observed during the annealing hold time, suggests that the reduction in the drying time was because of improved connectivity of ice crystals because of Ostwald ripening rather than devitrification. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  13. Application of process analytical technology for monitoring freeze-drying of an amorphous protein formulation: use of complementary tools for real-time product temperature measurements and endpoint detection.

    Science.gov (United States)

    Schneid, Stefan C; Johnson, Robert E; Lewis, Lavinia M; Stärtzel, Peter; Gieseler, Henning

    2015-05-01

    Process analytical technology (PAT) and quality by design have gained importance in all areas of pharmaceutical development and manufacturing. One important method for monitoring of critical product attributes and process optimization in laboratory scale freeze-drying is manometric temperature measurement (MTM). A drawback of this innovative technology is that problems are encountered when processing high-concentrated amorphous materials, particularly protein formulations. In this study, a model solution of bovine serum albumin and sucrose was lyophilized at both conservative and aggressive primary drying conditions. Different temperature sensors were employed to monitor product temperatures. The residual moisture content at primary drying endpoints as indicated by temperature sensors and batch PAT methods was quantified from extracted sample vials. The data from temperature probes were then used to recalculate critical product parameters, and the results were compared with MTM data. The drying endpoints indicated by the temperature sensors were not suitable for endpoint indication, in contrast to the batch methods endpoints. The accuracy of MTM Pice data was found to be influenced by water reabsorption. Recalculation of Rp and Pice values based on data from temperature sensors and weighed vials was possible. Overall, extensive information about critical product parameters could be obtained using data from complementary PAT tools. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Effects of a Proprietary Freeze-Dried Water Extract of Eurycoma longifolia (Physta) and Polygonum minus on Sexual Performance and Well-Being in Men: A Randomized, Double-Blind, Placebo-Controlled Study.

    Science.gov (United States)

    Udani, Jay K; George, Annie A; Musthapa, Mufiza; Pakdaman, Michael N; Abas, Azreena

    2014-01-01

    Background. Physta is a proprietary product containing a freeze-dried water extract of Eurycoma longifolia (tongkat ali), which is traditionally used as an energy enhancer and aphrodisiac. We aim to evaluate a 300 mg combination of Physta and Polygonum minus, an antioxidant, with regard to sexual performance and well-being in men. Methods. Men that aged 40-65 years were screened for this 12-week randomized, double-blind, placebo-controlled, parallel-group study. Outcome measures included validated questionnaires that aimed to evaluate erectile function, satisfaction with intervention, sexual intercourse performance, erectile hardness, mood, and overall quality of life. Results. 12 subjects in the active group and 14 in the placebo group completed the study. Significant improvements were noted in scores for the Sexual Intercourse Attempt diary, Erection Hardness Scale, Sexual Health Inventory of Men, and Aging Male Symptom scale (P < 0.05 for all). Three adverse events were reported in the active group and four in the placebo group, none of which were attributed to study product. Laboratory evaluations, including liver and kidney function testing, showed no clinically significant abnormality. Conclusion. Supplementation for twelve weeks with Polygonum minus and the proprietary Eurycoma longifolia extract, Physta, was well tolerated and more effective than placebo in enhancing sexual performance in healthy volunteers.

  15. Effects of a Proprietary Freeze-Dried Water Extract of Eurycoma longifolia (Physta and Polygonum minus on Sexual Performance and Well-Being in Men: A Randomized, Double-Blind, Placebo-Controlled Study

    Directory of Open Access Journals (Sweden)

    Jay K. Udani

    2014-01-01

    Full Text Available Background. Physta is a proprietary product containing a freeze-dried water extract of Eurycoma longifolia (tongkat ali, which is traditionally used as an energy enhancer and aphrodisiac. We aim to evaluate a 300 mg combination of Physta and Polygonum minus, an antioxidant, with regard to sexual performance and well-being in men. Methods. Men that aged 40–65 years were screened for this 12-week randomized, double-blind, placebo-controlled, parallel-group study. Outcome measures included validated questionnaires that aimed to evaluate erectile function, satisfaction with intervention, sexual intercourse performance, erectile hardness, mood, and overall quality of life. Results. 12 subjects in the active group and 14 in the placebo group completed the study. Significant improvements were noted in scores for the Sexual Intercourse Attempt diary, Erection Hardness Scale, Sexual Health Inventory of Men, and Aging Male Symptom scale (P<0.05 for all. Three adverse events were reported in the active group and four in the placebo group, none of which were attributed to study product. Laboratory evaluations, including liver and kidney function testing, showed no clinically significant abnormality. Conclusion. Supplementation for twelve weeks with Polygonum minus and the proprietary Eurycoma longifolia extract, Physta, was well tolerated and more effective than placebo in enhancing sexual performance in healthy volunteers.

  16. The effect of combined Moringa oleifera and demineralized freeze-dried bovine bone xenograft on the amount of osteoblast and osteoclast in the healing of tooth extraction socket of Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Rostiny Rostiny

    2016-12-01

    Full Text Available Background: Alveolar bone has an important role in providing support to teeth and dentures. Loss of support caused by alveolar resorption will cause functional and aesthetic problems. Preservation socket using bone graft is one way to maintain the dimensions of the alveolar bone. Moringa oleifera leaf can increase the activity of bone graft in the formation of new bone. Purpose: This study was aimed to evaluate the effect of combined Moringa oleivera leaf extract and demineralized freeze-dried bovine bone xenograft (DFDBBX towards the formation of osteoblasts and osteoclasts in the tooth extraction sockets of cavia cobaya. Method: This study used 28 cavia cobayas divided into four groups. The combination of Moringa oleifera leaf extract and DFDBBX was inducted into the sockets of lower incisor tooth with certain dose in each group, ointment 1 containing PEG (a mixture of PEG 400 and PEG 4000 for control group, ointment 2 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active subtance consentration of 0.5% for group 1, ointment 3 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance concentration of 1% for group 2, and Ointment 4 containing Moringa oleifera leaf extract and DFDBBX and PEG (at active substance consentration of 2% for group 3. paraffin block preparations were made for histopathology examination using hematoxylin eosin staining. Result: The results showed that there were significant differences of the number of osteoblasts and osteoclasts in each treatment group (p <0.05. Conclusion: It can be concluded that the combination of Moringa oleifera leaf extract and DFDBBX at 2% cocentration can increase the number of osteoblasts and decrease osteoclasts in the healing of tooth extraction sockets of cavia cobaya.

  17. Comparison between autogenous iliac bone and freeze-dried bone allograft for repair of alveolar clefts in the presence of plasma rich in growth factors: A randomized clinical trial.

    Science.gov (United States)

    Shirani, Gholamreza; Abbasi, Amir J; Mohebbi, Simin Z; Moharrami, Mohammad

    2017-10-01

    This study aimed to compare the effectiveness of alveolar cleft repair using iliac bone and freeze-dried bone allograft (FDBA) in the presence of plasma rich in growth factors (PRGF). Patients with unilateral alveolar cleft (n = 32) were randomly allocated to either the iliac plus PRGF group or the FDBA plus PRGF group. CBCT images were obtained before and 6 months after the surgery to assess the regenerated bone volume. Paired t-tests and two-way analysis of variance (ANOVA) were applied to analyze the data using SPSS 16.0 software. The patients' mean age was 15 ± 5.7 years (range = 8-27). In the iliac plus PRGF group, the mean volume of cleft before the surgery and the mean regenerated bone volume 6 months after were 1.67 ± 0.66 and 1.14 ± 0.47 cm 3 , respectively. The corresponding values were 1.5 ± 0.54 and 0.72 ± 0.23 cm 3 in the FDBA plus PRGF group. The remaining bone to cleft volume ratio was not associated with grafting time (secondary or tertiary) and the original cleft volume. Iliac bone reinforced with PRGF was more successful than FDBA plus PRGF in repairing alveolar cleft (p = 0.007). Due to the poor performance of the allograft, autografts should still be preferred in spite of possible donor site morbidity. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  18. A comparative evaluation of freeze-dried bone allograft with and without bioabsorbable guided tissue regeneration membrane Healiguide® in the treatment of Grade II furcation defects: A clinical study

    Directory of Open Access Journals (Sweden)

    Deept Jain

    2015-01-01

    Full Text Available Background: Furcation defects represent one of the most demanding therapeutic challenges for periodontal therapy. Various treatment modalities have been tried with different success rates. The present study was undertaken to evaluate the efficacy of freeze-dried bone allograft (FDBA with and without bioabsorbable guided tissue regeneration (GTR membrane Healiguide® in the treatment of Grade II furcation defects. Materials and Methods: Ten patients with bilateral Grade II furcation defects were selected for the study. After phase I therapy, subjects were divided into two arms and treated in a split-mouth design. Ten defects were treated with FDBA alone in the control arm. Ten defects were treated with FDBA in conjunction with bioabsorbable GTR membrane Healiguide® in test arm. Clinical parameters like plaque index, gingival index, vertical probing depth, horizontal probing depth, and relative attachment level (RAL were assessed at baseline, 3 months, and 6 months postoperatively. Results: At 6 months, clinical improvement was seen in both the arms with mean pocket depth reduction of 1.2 ± 1.032 mm and 1.7 ± 0.948 mm and mean horizontal probing depth reduction being 2.1 ± 1.969 mm and 1.6 ± 1.264 mm in control and test arm, respectively. Both surgical procedures resulted in a statistically significant reduction in vertical and horizontal probing depths. Conclusion: Both the arms demonstrated a significant improvement in the probing depth, horizontal furcation depth, and RAL at 6 months postsurgery in the treatment of Grade II furcation defects. However, on the intergroup comparison, there was no statistically significant difference in the results achieved between two arms.

  19. Incorporating freeze-dried strawberry powder into a high-fat meal does not alter postprandial vascular function or blood markers of cardiovascular disease risk: a randomized controlled trial.

    Science.gov (United States)

    Richter, Chesney K; Skulas-Ray, Ann C; Gaugler, Trent L; Lambert, Joshua D; Proctor, David N; Kris-Etherton, Penny M

    2017-02-01

    Postprandial dysmetabolism-an exaggerated spike in triglycerides, glucose, and insulin-increases cardiovascular disease risk by inducing oxidative stress, inflammation, and endothelial dysfunction. Polyphenol-rich foods may blunt these effects when they are incorporated into a high-fat, calorie-dense meal. Strawberries are a rich source of polyphenols, but there is little research on their postprandial effects. This study was designed to investigate the effect of adding 40 g freeze-dried strawberry powder (∼1 lb. or 0.45 kg fresh strawberries) to a high-fat (50 g total fat) meal on postprandial vascular function, as well as triglyceride, glucose, and insulin responses. Healthy, overweight or obese [mean ± SEM body mass index (in kg/m 2 ): 31 ± 0.5] adults (mean ± SEM age: 28 ± 2 y; 17 men and 13 women) consumed a control meal and a strawberry meal in a randomized crossover design. Testing sessions were separated by ≥1 wk for men and ∼1 mo for women to control for hormonal variations. Blood samples were obtained before the meal and 0.5, 1, 2, and 4 h after the meal. Central blood pressure and arterial stiffness indexes were measured at baseline and 2 and 4 h postmeal with the use of pulse waveform analysis. There were no significant differences between the strawberry and control meals for any outcomes. Consumption of either meal significantly decreased the augmentation index at 2 and 4 h (P triglycerides, insulin, and glucose at all time points (P triglycerides, glucose, or insulin relative to the control meal. Additional research is needed to clarify whether strawberries or other polyphenol-rich interventions improve postprandial responses, and future studies should take into account the acute meal-induced improvements in measures of vascular function. This trial was registered at clinicaltrials.gov as NCT01989637. © 2017 American Society for Nutrition.

  20. Estabilidade da microestrutura e do teor de carotenóides de pós obtidos da polpa de pequi (Caryocar brasiliense Camb. liofilizada Stability of the microstructure and carotenoids contents of the freeze-dried pequi (Caryocar brasiliense Camb. pulp in the powdered form

    Directory of Open Access Journals (Sweden)

    Cibele Cristina de Oliveira Alves

    2008-12-01

    Full Text Available Pós obtidos a partir da polpa (mesocarpo interno de pequi (Caryocar brasiliense Camb. liofilizada, elaborados com adição de alcoóis (etanol e isopropanol, em concentrações de 0, 5 e 10% e de açúcares (sacarose e frutose, em concentrações de 0, 5 e 10%, foram desenvolvidos neste trabalho. Análises microestruturais por microscopia fotônica dos pós de pequi liofilizados foram feitas para visualizar o grau de cristalinidade. Também foram feitas análises de cor usando colorímetro Minolta e dos teores de carotenóides totais por espectrofotometria. Os resultados mostraram que tratamentos constituídos da combinação de sacarose e etanol foram os que apresentaram formação de estruturas cristalinas e melhor preservação dos carotenóides. O teor de carotenóides nos pós obtidos da polpa de pequi liofilizada é mais bem preservado quanto maior for a concentração do álcool adicionado nos pré-tratamentos. Tratamentos com frutose e isopropanol produziram pós tipicamente amorfos, com ocorrência do fenômeno de caking. Pré-tratamentos com sacarose e etanol são os indicados para a produção de pós de pequi liofilizados com estabilidade físico-química e microestrutural.In this study, food powders obtained from the freeze-dried pequi (Caryocar brasiliense Camb. pulps (internal mesocarp were developed by adding alcohols (ethanol and isopropyl alcohol in concentrations of 0, 5, and 10% and sugars (sucrose and fructose in concentrations of 0, 5, and 10%. Microstructure analyses by photonic microscopy of the freeze-dried powders were used to evaluate the degree of crystallization. Color analyses using a Minolta colorimeter and the total carotenoid values using a spectrophotometer were also done. The results show that treatments with a sucrose and ethanol combination presented the formation of crystalline structures and the best preservation of the carotenoid contents. The higher the concentration of the alcohol added in the pre

  1. Embriões liofilizados e flocos de Artemia no cultivo pós-larval de Litopenaeus vannamei (Boone, 1931 = Use of freeze-dried embryos and Artemia flakes in the post-larval culture of Litopenaeus vannamei (Boone, 1931

    Directory of Open Access Journals (Sweden)

    Pedro Hercílio de Oliveira Cavalcante

    2008-01-01

    Full Text Available O objetivo do estudo foi avaliar o crescimento e sobrevivência de 1pós-larvas de Litopenaeus vannamei que receberam embriões liofilizados (EMB e flocos (FLO de Artemia como suplementos alimentares a uma dieta microparticulada (DMP. Nos tratamentos T1,T2 e T3, os camarões receberam DMP e após 2h, acréscimos de FLO (T1; de EMB (T2; e da mesma DMP, anteriormente, ofertada (T3. No T4, as pós-larvas foram alimentadas com DMP, mas sem suplementações posteriores. Não houve diferença significativa (p > 0,05 na sobrevivência dos camarões após o período experimental de 21 dias. Por outro lado, o ganho de peso absoluto (mg peso seco das pós-larvas, cuja dieta foi suplementada com BEM, foi significativamente superior (p The objective of the study was to evaluate the growth and survival of Litopenaeus vannamei post-larvae fed with freeze-driedembryos and Artemia flakes as feeding supplements to a microparticulate diet (DMP. In treatments T1, T2 and T3, the shrimp were fed with DMP and after 2 hours, received supplements of FLO (T1; EMB (T2; and the same DMP previously offered (T3. In T4,post-larvae were fed with DMP but without additional supplementation. There was no significant difference (p > 0.05 in shrimp survival after the experimental period of 21 days. On the other hand, the absolute weight gain (mg of dry weight of post-larvae whose dietwas supplemented with EMB (T2 was significantly higher (p < 0.05 than growth found in the other experimental groups (T1, T3 and T4. Shrimp fed with DMP and EMB obtained a significantly higher absolute weight gain (6.7 mg than those found in treatments that used DMP and FLO (5.4 mg or DMP alone (5.8 mg in T3 and 5.7 mg in T4. Theseresults underline the nutritional value of freeze-dried Artemia embryos and recommend their inclusion in the post-larval diet of Litopenaeus vannamei.

  2. Fotossensibilidade e termoestabilidade de vacinas contra o sarampo (cepa Biken CAM-70 liofilizadas e/ou reconstituídas para administração Photosensitivity and stability of freeze-dried and reconstituted (Biken CAM-70 strain measles vaccines

    Directory of Open Access Journals (Sweden)

    Edda de Rizzo

    1990-02-01

    ou reconstituídos para administração apresentaram, além de baixa estabilidade ao calor, pouca homogeneidade com relação a este parâmetro.Three different lots of measles vaccines produced with the Biken CAM-70 virus strain were requested from the central cold store of the Public Health Department of the State of S. Paulo, Brazil, and assays on photosensitivity at 2-8° C, and on stability at 28, 36.5 and 45° C were carried out to find out for how long these vaccines would maintain their minimum potency, established as being 3.70 log10 or 5000 TCID50 (50% tissue culture infective dose per human dose. The analysis of the adjusted straight regression lines indicated that, with the passage of time, the potency of lyophilized or reconstituted vaccines, as well as of vaccines exposed to or protected from light decreased. Light-exposed vaccines, however, became less potent than vaccines protected from the light. None of the vaccine lots studied, reconstituted and stored at 2-8° C, exhibited homogeneity as to sensitivity to light. When freeze-dried vaccines had their photosensitivity studied at 2-8° C, lots 1 and 2 presented greater thermal degradation when exposed to light than when protected from it. However, in both instances, it was found that potency fell bellow that taken as minimum for the Biken CAM-70 virus strain. At all other temperatures considered, even when protected from light, lots 1 and 2 did not retain the minimum potency. Lot 3 kept the expected stability for 60 days at 2-8° C when protected from light and for 40 days when unprotected, but its thermal degradation at other temperatures was more intense (28° C: 5 days; 36.5° C: 2 days; 45° C: 0.5 day. Taking into account the potency that measles vaccines produced with the Biken CAM-70 virus strain are required to contain in order to induce effective immunity, the three vaccine lots studied were found to possess low thermal stability and to lack homogeneity both in the freeze-dried as well as in

  3. Cinética de degradação do ácido ascórbico em ameixas liofilizadas Kinetic of ascorbic acid degradation in freeze-dried prunes

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Gabas

    2003-12-01

    Full Text Available Realizou-se a modelagem da degradação de vitamina C em ameixas desidratadas e submetidas a diferentes condições de temperatura e umidade relativa, com o auxílio da equação de Bigelow. As ameixas in natura foram liofilizadas e acondicionadas em dessecadores contendo diferentes soluções salinas saturadas na temperatura de 4ºC. Após atingir o equilíbrio, os dessecadores foram submetidos a temperaturas na faixa que variou entre 40 e 80ºC. A degradação de vitamina C foi analisada ao longo de 5 dias, aplicando-se o método de titulação com solução padronizada de 2,6-diclorofenolindofenol 0,01%. As amostras apresentaram os seguintes conteúdos de umidade: 0,05; 0,11; 0,18; 0,38 e 1,40g água/g sólido seco. A partir dos parâmetros da equação de Bigelow, tempo de redução decimal (D T e valor z, os resultados indicaram que as amostras submetidas à faixa de temperatura entre 40 - 60ºC apresentaram uma perda mais lenta de vitamina C (D T no conteúdo de umidade de 0,05 apresentou valores na faixa de 1672 - 275h. Por outro lado, em altas temperaturas a degradação do ácido ascórbico ocorreu mais rapidamente (D T para X = 0,05 forneceu valores entre 110 e 47h. Os parâmetros z e D T apresentaram uma dependência linear e quadrática com o conteúdo de umidade das amostras, respectivamente. De modo geral, em altos teores de umidade, houve uma maior perda de vitamina C, devido a sua alta solubilidade.The degradation of vitamin C in prunes submitted to different conditions of temperature and moisture content was modeling by using the Bigelow equation. Firstly, plums were freeze-dried and conditioned in dessecators with different saturated salt solutions at 4ºC. After reaching the equilibrium, dessecators were submitted to a range of temperature between 40 to 80ºC. The vitamin C degradation was analyzed during 5 days, by applying the titration method with patronized solution of 2,6-dichlorophenolindophenol 0.01%. Samples presented

  4. Determination of sensitivity of staphylococcus SPP to xeno-graft of pig to be radio-sterilized subsequently with ionizing

    International Nuclear Information System (INIS)

    Rojas Tapia, Carolina

    2011-01-01

    The use of the pork skin heterograft or xenograft, as a temporary biological dressing in the treatment of extreme burns patients, may cause a risk due to the transmission of pathogenic bacteria of the genus Staphylococcus spp colonizing the outer part of the skin. The objective of this study was to determine the sensitivity of Staphylococcus spp from porcine xenograft, against ionizing energy and by antibiogram, which was carried out in the Radio-sterilized Biological Tissue Processing Laboratory (LPTR) of the Chilean Nuclear Energy Commission, in together with the Microbiology Laboratory of the Santo Tomas University. The hides of pigs are processed to obtain sterile porcine xenograft. The determination of the radiosensitivity of Staphylococcus hyicus and epidermidis, required the use of 15 samples of pig skin of 0.5g sterile, for each species of Staphylococcus analyzed. Subsequently, the pig skins are contaminated with Staphylococcus hyicus and epidermidis. Once the contamination was finished, the samples were subjected to an irradiation dose of 0.2; 0.4; 0.6; 0.8 KGy, plus a control (without irradiation), to finally perform a microbiological count, which allowed to determine a DIO value that for Staphylococcus hyicus that was approximately 0.25KGy and for Staphylococcus epidermidis was approximately 0.29KGy. The microbial susceptibility tested by traditional antibiogram for Staphylococcus aureus, hyicus and epidermidis, allowed concluding that all staphylococci analyzed in the present study were sensitive to antibiotics: Cloxacillin, Amoxicillin + Ac clavulanic and Gentamicin, however were resistant to Penicillin and Erythromycin

  5. Immunogenicity and safety of a novel MMR vaccine (live, freeze-dried) containing the Edmonston-Zagreb measles strain, the Hoshino mumps strain, and the RA 27/3 rubella strain: Results of a randomized, comparative, active controlled phase III clinical trial.

    Science.gov (United States)

    Sood, Ashwani; Mitra, Monjori; Joshi, Himanshu Arvind; Nayak, Uma Siddhartha; Siddaiah, Prashanth; Babu, T Ramesh; Mahapatro, Samarendra; Sanmukhani, Jayesh; Gupta, Gaurav; Mittal, Ravindra; Glueck, Reinhard

    2017-07-03

    This phase III clinical trial was conducted to evaluate the immunogenicity and safety of the single-dose and multi-dose formulations of a novel MMR vaccine (live, freeze-dried) developed by M/s Cadila Healthcare Limited, India (Cadila MMR vaccine), containing the Hoshino mumps strain, compared to that of an existing MMR vaccine (live, freeze-dried) developed by M/s Serum Institute of India Limited, India (Serum MMR vaccine). These two vaccines have similar measles and rubella strains, but different mumps strains (Hoshino in Cadila MMR vaccine, and L-Zagreb in Serum MMR vaccine). Three hundred and twenty-eight subjects of either sex, aged 15-18 months, were randomized in a 2:1 ratio to receive either the Cadila or Serum MMR vaccine. Immunogenicity assessments (IgG antibodies against measles, mumps, and rubella viruses) were done at baseline and 42 d after vaccination. Solicited (local and systemic) and unsolicited adverse events were recorded for up to 42 d following vaccination. The Cadila MMR vaccine was found to be non-inferior to the Serum MMR vaccine in terms of end-of-study proportion of subjects seropositive for anti-measles antibodies (100.0% in both groups), anti-mumps antibodies (94.5% vs. 94.0%), and anti-rubella antibodies (95.5% vs. 91.0%). Both vaccines were well tolerated by all study participants; the most common adverse event reported in both groups was fever, followed by rash. The results of this phase III clinical trial show that the novel Cadila MMR vaccine is non-inferior to the Serum MMR vaccine.

  6. Radiation preservation of biological tissues with special emphasis on immunological alterations. Part of a coordinated programme on radiosterilization of medical products and biological tissues

    International Nuclear Information System (INIS)

    Feher, I.

    1977-01-01

    A method suitable for clinical use and preparations of tendon and skin preserved by lyophilization and radiosterilization were investigated. The fate of the graft was detected by histological and electronmicroscopical investigations. We demonstrated that the implanted preparation was desorganized and was absorbed within six weeks. Clinical examinations were made on pig-tendon preparations. Patients recovered without difficulties in every case. Skin preparations were prepared of pig-skin. It was demonstrated by indirect haemagglutination that pig-skin antigenity was decreased by approximately two orders of magnitude during the preservation process. The clinical application of skin preparations has been used for nearly two years. It is effectively used as a biological dressing for the covering of wound surface in case of burn injuries

  7. Effect of electron beam radio-sterilization on cyclo olefin copolymers and its impact on the interactions with other active molecules

    International Nuclear Information System (INIS)

    Barakat, H.

    2013-01-01

    The aim of this work was to study the effect of electron beam radio-sterilization on cyclo olefins copolymers (COC) used as pharmaceutical storage materials, as well as to investigate its impact on the interaction with pharmaceuticals formulations. Due to the analytical methodology used which has dealt with different techniques of characterization such as size exclusion chromatography, reversed phase high performance liquid chromatography, Fourier transformed infrared spectroscopy, atomic force microscopy and contact angle measurements, we have been able to put into evidence different kinds of modifications both in the bulk and on the surface of the sterilized material and also after ageing. The principal modification of material's bulk, observed at the recommended dose for sterilization (25 kGy), was polymer chains scissions, accompanied with creation of low molecular weight compounds, that are potentials migrants that are likely to affect the safe use of COC. Indeed, some of these compounds have been found with a relatively important concentration in the solutions where sterilized COC has been stored, especially in aqueous solutions. However, the preliminary study of toxicity has shown the absence of cytotoxicity of the extractable by-products obtained at the sterilization dose. Surface modifications of radio-sterilized COC are of two types: a physical one, with an increase of the surface's roughness and a chemical one with the formation of polar oxidation products; these two modifications result in an increase of surface's wettability that may be important. However, in some cases such as for aged samples, these modifications are relatively weak even at doses higher than the one recommended for sterilization, which can explain the absence of the effect of radiation on the behavior of COC concerning drug solutions. Indeed, no variation of drug sorption has been observed between irradiated aged COC and no-irradiated aged COC. (author)

  8. A freeze-dried kit formulation for the preparation of Lys27(99mTc-EDDA/HYNIC)-Exendin(9-39)/99mTc-EDDA/HYNIC-Tyr3-Octreotide to detect benign and malignant insulinomas

    International Nuclear Information System (INIS)

    Medina-García, Veronica; Ocampo-García, Blanca E.; Ferro-Flores, Guillermina; Santos-Cuevas, Clara L.; Aranda-Lara, Liliana; García-Becerra, Rocio; Ordaz-Rosado, David; Melendez-Alafort, Laura

    2015-01-01

    About 90% of insulinomas are benign and 5%–15% are malignant. Benign insulinomas express the glucagon-like peptide-1 receptor (GLP-1R) and low levels of somatostatin receptors (SSTR), while malignant insulinomas over-express SSTR or GLP-1R in low levels. A kit for the preparation of Lys 27 ( 99m Tc-EDDA/HYNIC)-Exendin(9-39)/ 99m Tc-EDDA/HYNIC-Tyr 3 Octreotide was formulated to detect 100% of insulinomas. The formulation showed radiochemical purity of 97 ± 1%, high stability in human serum, and GLP-1R and SSTR affinity. The biodistribution and imaging studies demonstrated properties suitable for its use as a target-specific agent for the simultaneous molecular imaging of GRP-1R- and/or SSTR-positive tumors.

  9. A freeze-dried kit formulation for the preparation of Lys(27)(99mTc-EDDA/HYNIC)-Exendin(9-39)/99mTc-EDDA/HYNIC-Tyr3-Octreotide to detect benign and malignant insulinomas.

    Science.gov (United States)

    Medina-García, Veronica; Ocampo-García, Blanca E; Ferro-Flores, Guillermina; Santos-Cuevas, Clara L; Aranda-Lara, Liliana; García-Becerra, Rocio; Ordaz-Rosado, David; Melendez-Alafort, Laura

    2015-12-01

    About 90% of insulinomas are benign and 5%-15% are malignant. Benign insulinomas express the glucagon-like peptide-1 receptor (GLP-1R) and low levels of somatostatin receptors (SSTR), while malignant insulinomas over-express SSTR or GLP-1R in low levels. A kit for the preparation of Lys(27)((99m)Tc-EDDA/HYNIC)-Exendin(9-39)/(99m)Tc-EDDA/HYNIC-Tyr(3)Octreotide was formulated to detect 100% of insulinomas. The formulation showed radiochemical purity of 97±1%, high stability in human serum, and GLP-1R and SSTR affinity. The biodistribution and imaging studies demonstrated properties suitable for its use as a target-specific agent for the simultaneous molecular imaging of GRP-1R- and/or SSTR-positive tumors. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Biochemical effects on long-term frozen human costal cartilage

    International Nuclear Information System (INIS)

    Santin, Stefany P.; Martinho Junior, Antonio C.; Yoshito, Daniele; Soares, Fernando A.N.; Mathor, Monica B.

    2011-01-01

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  11. Biochemical effects on long-term frozen human costal cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Santin, Stefany P.; Martinho Junior, Antonio C.; Yoshito, Daniele; Soares, Fernando A.N.; Mathor, Monica B., E-mail: mathor@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Currently, the progresses on treatment of musculoskeletal diseases with the evolving of artificial implants and the success of tissue transplantation between genetically different individuals have conducted to an increase in radiosterilization. Regarding to tissue transplantation, it is essential to have sterile tissue and many tissue banks use radiosterilization as an effective method to sterilize these tissues. However, high doses of ionizing radiation and the preservation method may induce structural modifications in the tissues, as degradation of structural scaffold, decreasing its mechanical properties. Particularly, cartilage have been preserved in high concentrations of glycerol or deep-frozen at -70 degree C for storage after radiosterilization. Therefore, it is important to study the modifications induced in cartilage by preservation methods and by radiosterilization to determine the appropriated parameters for high quality of human allografts. Costal cartilages were obtained from cadaveric donors and were frozen at -20 degree C for 2 years long in order to compare with previous studies for fresh, deep-frozen and glycerolised cartilages. The mechanical tests were carried out in a universal testing machine until sample failure. According our results, there is no significant statistical difference between stress at break of fresh, long-term - 20 degree C frozen cartilages and deep-frozen cartilage. This early result suggests, regarding to tensile property, that long-term - 20 degree C frozen cartilages corresponds to glycerolised costal cartilages irradiated with 25 kGy or deep-frozen cartilages irradiated with 25 and 50 kGy. Thus, this long-term frozen cartilages may be used for tissue banks, but more studies about effects of ionizing radiation are necessary. (author)

  12. Lithium-Rich Nanoscale Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 Cathode Material Prepared by Co-Precipitation Combined Freeze Drying (CP-FD) for Lithium-Ion Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Ying; Li, Yu; Wu, Chuan; Lu, Jun; Li, Hui; Liu, Zhaolin; Zhong, Yunxia; Chen, Shi; Zhang, Cunzhong; Amine, Khalil; Wu, Feng

    2015-07-14

    Nanoscale Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 material is synthesized by a co-precipitation combined freeze drying (CP-FD) method, and compared with a conventional co-precipitation method combined vacuum drying (CP-VD). With the combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM), it is found that the sample from CP-FD method consists of a pure phase with good crystallinity and small, homogenous particles (100-300 nm) with uniform particle size distribution. Inductively coupled plasma spectroscopy (ICP) shows that the sample has a stoichiometric ratio of n((Li)): n((Mn)): n((Ni)): n((Co))=9: 4: 1: 1; and its Brunauer-Emmett-Teller (BET) specific surface area is 5.749 m(2)g(-1). This sample achieves excellent electrochemical properties: its initial discharge capacities are 298.9 mAhg(-1) at 0.1C (20 mAg(-1)), 246.1 mAhg(-1) at 0.5C, 215.8 mAhg(-1) at 1C, and 154.2 mAhg(-1) at 5C (5C charge and 5C discharge), as well as good cycling performance. In addition, the Li+ chemical diffusion coefficient of Li1.2Mn0.54Ni0.13Co0.13O2 material prepared by the CP-FD method is 4.59 x 10(-11) cm(2) s(-1), which is higher than that of the Li1.2Mn0.54Ni0.13Co0.13O2 material prepared by CP-VD. This phenomenon illustrates the potential for Li1.2Mn0.54Ni0.13Co0.13O2 with good rate performance synthesized by CP-FD method.

  13. Anthocyanins standards (cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside isolation from freeze-dried açaí (Euterpe oleraceae Mart. by HPLC Isolamento de padrões de antocianinas (cianidina-3-O-glucosídeo e cianidina -3-O-rutinosídeo de açaí liofilizado (Euterpe oleraceae Mart. por CLAE

    Directory of Open Access Journals (Sweden)

    Ana Cristina Miranda Senna Gouvêa

    2012-03-01

    Full Text Available Availability of analytical standards is a critical aspect in developing methods for quantitative analysis of anthocyanins. The anthocyanins cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside were isolated from samples of freeze-dried açaí (Euterpe oleraceae Mart., which is a round and purple well-known palm fruit in Brazil, and then used as standards. The isolation of the anthocyanins was performed by High Performance Liquid Chromatography (HPLC, using an adapted six-channel selection valve. The identification of anthocyanin pigments in açaí was based on mass spectrometric data for molecular ions and MS-MS product ions and on previous published data. After the collection procedure, standards with a high purity grade were obtained and an external standard curve of each anthocyanin was plotted.Disponibilidade de padrões analíticos é um aspecto crítico no desenvolvimento de métodos de análises quantitativas de antocianinas. Para a obtenção dos padrões isolados de antocianinas cianidina-3-O-glicosídeo e cianidina-3-O-rutinosídeo foram utilizadas amostras liofilizadas de açaí (Euterpe oleraceae Mart., que é um conhecido fruto de palmeiras no Brasil de forma arredondada e roxo. O isolamento das antocianinas foi realizado por Cromatografia Líquida de Alta Eficiência (CLAE, utilizando uma válvula seletora de seis canais. A identificação de antocianinas no açaí foi baseada em dados publicados na literatura e por espectrometria de massas. Após a coleta, padrões com um alto grau de pureza foram obtidos e uma curva para padronização externa de cada antocianina foi feita.

  14. Embriões liofilizados e flocos de Artemia no cultivo pós-larval de Litopenaeus vannamei (Boone, 1931 - DOI: 10.4025/actascibiolsci.v30i1.1424 Use of freeze-dried embryos and Artemia flakes in the post-larval culture of Litopenaeus vannamei (Boone, 1931 - DOI: 10.4025/actascibiolsci.v30i1.1424

    Directory of Open Access Journals (Sweden)

    Pedro Hercílio de Oliveira Cavalcante

    2008-03-01

    Full Text Available O objetivo do estudo foi avaliar o crescimento e sobrevivência de pós-larvas de Litopenaeus vannamei que receberam embriões liofilizados (EMB e flocos (FLO de Artemia como suplementos alimentares a uma dieta microparticulada (DMP. Nos tratamentos T1, T2 e T3, os camarões receberam DMP e após 2h, acréscimos de FLO (T1; de EMB (T2; e da mesma DMP, anteriormente, ofertada (T3. No T4, as pós-larvas foram alimentadas com DMP, mas sem suplementações posteriores. Não houve diferença significativa (p > 0,05 na sobrevivência dos camarões após o período experimental de 21 dias. Por outro lado, o ganho de peso absoluto (mg peso seco das pós-larvas, cuja dieta foi suplementada com BEM, foi significativamente superior (p Artemia e recomendam sua inclusão na dieta pós-larval de Litopenaeus vannameiThe objective of the study was to evaluate the growth and survival of Litopenaeus vannamei post-larvae fed with freeze-dried embryos and Artemia flakes as feeding supplements to a microparticulate diet (DMP. In treatments T1, T2 and T3, the shrimp were fed with DMP and after 2 hours, received supplements of FLO (T1; EMB (T2; and the same DMP previously offered (T3. In T4, post-larvae were fed with DMP but without additional supplementation. There was no significant difference (p > 0.05 in shrimp survival after the experimental period of 21 days. On the other hand, the absolute weight gain (mg of dry weight of post-larvae whose diet was supplemented with EMB (T2 was significantly higher (p Artemia embryos and recommend their inclusion in the post-larval diet of Litopenaeus vannamei

  15. Freeze drying method for preparing radiation source material

    International Nuclear Information System (INIS)

    Mosley, W.C. Jr.; Smith, P.K.

    1975-01-01

    A solution containing radioisotope and palladium values is atomized into an air flow entering a cryogenically cooled chamber where the solution is deposited on the chamber walls as a thin layer of frozen material. The solvent portion of the frozen material is sublimated into a cold trap by elevating the temperature within the chamber while withdrawing solvent vapors. The residual crystals are heated to provide a uniformly mixed powder of palladium metal and a refractory radioisotope compound. The powder is thereafter consolidated into a pellet and further shaped into rod, wire or sheet form for easy apportionment into individual radiation sources. (U.S.)

  16. Improving the Quality of Freeze Dried Rice: Initial Evaluations

    Science.gov (United States)

    2015-05-01

    a soft consistency and swells more during this period without disintegration of cell walls [10]. Evaluation of freshly cooked rice 4.1.2...synthetic/ plastic aroma and flavour. Comparison between Parboiled and Control-A 4.1.6. A more detailed series of rehydration tests with texture...the clumps rapidly and easily disintegrated into individual grains. Control-C and Parboiled differed in colour post- cooking due to the different

  17. Proximate composition and sensory properties of freeze-dried ...

    African Journals Online (AJOL)

    These instant soups and the freshly prepared portions were subjected to proximate and sensory analysis using standard methods. The results of the analysis showed that instant egusi soup contained 10.89 % moisture, 16.93 % ash, 19.73 % crude protein, 15.19 % fat, 13.95 % crude fibre and 23.30 % carbohydrate; while ...

  18. Analysis of food components of freeze-dried Alaska Pollack ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... companies. MATERIALS AND METHODS. Material preparation. Hwangtae, a product prepared in Yongdaeri (Inje, Korea), was used in this study. Sample was ground to make fine powder using liquid nitrogen with a mortar and a pestle. The powder was used for the analyses of minerals, amino acids, fatty ...

  19. Assessment of Delayed Skin Sensitivity Induced by Freeze-Dried ...

    African Journals Online (AJOL)

    The 8 schools which had already participated in the 1971 trial were again included on purpose. A Sub A .... field worker approximates this trial even more closely to routine field conditions than would have been the case .... percutaneous vaccine-a phenomenon which was hardly ever observed with the Glaxo percutaneous ...

  20. The reduction of population of cabbage pests plutela maculipennis curtis and crocidolomia binotalis zell as affected by the release of radiosterilized moths

    International Nuclear Information System (INIS)

    Hoedaya, M.S.; Sutrisno, S.; Nasroh, A.; Sastradihardja, S.I.

    1983-01-01

    Moths of plutella maculipennis curtis and crocidolimia binotalis zell radiosterilized with 30 Krad and 40 Krad of gamma radiation respectively were released into a laboratory-cage of 90 cm x 60 cm x 60 cm, a field-cage of 2 m x 2 m x 2 m and an experimental plot of 10 m x 15 m to study their effect on the reduction of F1-population. The release of 450 irradiated moths in the laboratory-cage containing 50 unirradiated moths can reduce the F1-population of plutella maculipennis and crocidolomia binotalis by 61.1% and 65.3% respectively. While in the field-cage the F1-population of plutella maculipennis and crocidolomia binotalis decreased by 55.6% and 50.55% respectively. The release of about 4.500 irradiated crocidolomia binotalis into an experimental plot containing 500 normal moths can reduce the F1-population by 41.02% in the dry season and 50.55% in the rainy season. The release of about 5.000 irradiated moths of plutella maculipennis into an experimental plot containing about 350 moths of natural population, resulted in a reduction of egg hatch from 85.9% in the unreleased plot to 17.0% in the released plot. (author)

  1. Reduction of population of cabbage pests plutela maculipennis curtis and crocidolomia binotalis zell as affected by the release of radiosterilized moths

    Energy Technology Data Exchange (ETDEWEB)

    Hoedaya, M.S.; Sutrisno, S.; Nasroh, A.; Sastradihardja, S.I. (National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre)

    1983-10-01

    Moths of plutella maculipennis curtis and crocidolimia binotalis zell radiosterilized with 30 Krad and 40 Krad of gamma radiation respectively were released into a laboratory-cage of 90 cm x 60 cm x 60 cm, a field-cage of 2 m x 2 m x 2 m and an experimental plot of 10 m x 15 m to study their effect on the reduction of F1-population. The release of 450 irradiated moths in the laboratory-cage containing 50 unirradiated moths can reduce the F1-population of plutella maculipennis and crocidolomia binotalis by 61.1% and 65.3% respectively, while in the field-cage the F1-population of plutella maculipennis and crocidolomia binotalis decreased by 55.6% and 50.55% respectively. The release of about 4,500 irradiated crocidolomia binotalis into an experimental plot containing 500 normal moths can reduce the F1-population by 41.02% in the dry season and 50.55% in the rainy season. The release of about 5,000 irradiated moths of plutella maculipennis into an experimental plot containing about 350 moths of natural population resulted in a reduction of egg hatch from 85.9% in the unreleased plot to 17.0% in the released plot.

  2. KIT of human polyclonal IGG for the I diagnostic of infectious processes

    International Nuclear Information System (INIS)

    Perera, Alejandro

    1997-01-01

    Early diagnosis of infections can be performed by using non-invasive techniques of Nuclear Medicine, even before appearing anatomical damage of the tissues. The main aim of the present work was to obtain a freeze-dried kit for direct labelling of human polyclonal IgG, for the detection of septic processes by scintigraphy. 99mT c-IgG labelling procedure was carried out by Schwarz method Its was obtained the best yields of 99m Tc using using sodium pyrophosphate decahydrate as a week chelating agent

  3. Development of a computational system for management of risks in radiosterilization processes of biological tissues; Desenvolvimento de um sistema computacional de gerenciamento de riscos em processos de radioesterilizacao de tecidos biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Cynara Viterbo

    2009-07-01

    Risk management can be understood to be a systematic management which aims to identify record and control the risks of a process. Applying risk management becomes a complex activity, due to the variety of professionals involved. In order to execute risk management the following are requirements of paramount importance: the experience, discernment and judgment of a multidisciplinary team, guided by means of quality tools, so as to provide standardization in the process of investigating the cause and effects of risks and dynamism in obtaining the objective desired, i.e. the reduction and control of the risk. This work aims to develop a computational system of risk management (software) which makes it feasible to diagnose the risks of the processes of radiosterilization of biological tissues. The methodology adopted was action-research, according to which the researcher performs an active role in the establishment of the problems found, in the follow-up and in the evaluation of the actions taken owing to the problems. The scenario of this action-research was the Laboratory of Biological Tissues (LTB) in the Radiation Technology Center IPEN/CNEN-SP - Sao Paulo/Brazil. The software developed was executed in PHP and Flash/MySQL language, the server (hosting), the software is available on the Internet (www.vcrisk.com.br), which the user can access from anywhere by means of the login/access password previously sent by email to the team responsible for the tissue to be analyzed. The software presents friendly navigability whereby the user is directed step-by-step in the process of investigating the risk up to the means of reducing it. The software 'makes' the user comply with the term and present the effectiveness of the actions taken to reduce the risk. Applying this system provided the organization (LTB/CTR/IPEN) with dynamic communication, effective between the members of the multidisciplinary team: a) in decision-making; b) in lessons learned; c) in knowing

  4. Preparation of Tc-99m human serum albumin using stannous citrate and stannous chloride

    International Nuclear Information System (INIS)

    El-Asrag, H.A.; El-Wetery, A.S.; El-Mohty, A.A.

    1988-01-01

    99mTc-albumin is widely used as radioactive indicator in the measurement of cardiac output by external counting techniques and in blood volume studies. The quality of 99mTc-albumin depends on the method of preparation. A comparative study had been carried out on the 99mTc-albumin preparation by the stannous chloride, stannous tartarate and stannous citrate method. The different parameters investigated for each method include: pH, albumin concentration, reductant concentration and ascorbic acid as antioxidant stabilizer. The biological distribution of 99mTc-albumin, prepared by different methods, were determined in mice and rats. A procedure was developed for the preparation of stannous human serum albumin (HSA) kit for human application the kit provides a freeze dried sterile formulation for reconstitution with sterile 99mTc pertechnetate solution to give 99mTc-Hsa, the effect of irradiation sterilization on the freeze dried kit was studied by spectrophotometric determination and biological distribution in mice and rats

  5. Gamma radiation effects on liofilized human serum

    International Nuclear Information System (INIS)

    Padron Soler, E.; Romay Penabad, Z.; Chavez Ardanza, A.; Hernandez Gonzalez, C.; Martin Gonzalez, O.; Garcia Gonzalez, I.; Prieto Miranda, E.

    1995-01-01

    Human freeze dried serum was artificially contaminated with Flavobacterium sp. for studying the effects of gamma radiation of it. The radiobiological parameters of the contaminator were determined and the sterilization dose was set. The quality of the product irradiated at both, calculated sterilization dose (8.5 kGy) an another one about 25 kGy was determined. It was made according to: sterility testing, total proteins, pH enzymes (alanina-aminotransferase, aspartato-aminotransferase, alkaline phosphatase), protein electrophoresis, fast performance liquid chromatographic and effect on the cellular growth. From the latter was concluded that the calculated sterilization dose was adequate form keeping the biological properties and viability of the irradiated serum. Nevertheless, the dose of 25 k Gy was not adequate because of its dangerous effects on the cell culture

  6. Progress in the processing of radioesterilized tissue

    International Nuclear Information System (INIS)

    Zarate S, H; Espinoza B, J; Ribbeck N, J; Vargas Q, M; Gutierrez D, K

    2003-01-01

    Since 1996, the Chilean Nuclear Energy Commission has been carrying out work to implement the first Radiosterilized Tissue Processing Laboratory (RTPL) in Chile, in order to introduce the use of sterilized biological tissue for clinical application. The International Atomic Energy Agency (IAEA) has provided collaboration and technical assistance for this work. The processing of biological tissues has been done in conjunction with physicians from different state hospital centers, mostly in the Metropolitan Region. Among the tissues primarily processed are allografts such as frozen human skin at - 80 o C, freeze-dried human bone and amniotic membrane. We have also been working with xenograft developments such as freeze-dried pig skin and demineralized ground cow bone. All these tissues are sterilized by means of gamma radiation, in order to obtain a sterility assurance level (SAL) of 10 -6 . This laboratory has already completed various stages, from the beginning when it was only just an idea up to the production stage where a large quantity of processed tissues have been delivered to physicians of different specialties, resulting in a contribution to medical science as well as to the treatment quality of a great many patients. The preliminary results and the opinions of those physicians who have used the processed products from our laboratory have encouraged us to continue developing new products, thus enlarging the scope of application (author)

  7. The effect of radiation sterilization on human transplantable bone

    International Nuclear Information System (INIS)

    Triantafyllou, N.; Karatzas, P.

    1974-11-01

    In order to study the effect of radiation sterilization on human transplantable bones, work was carried out on human and bovine bone tissue samples. Factors causing possible alterations in the mechanical structures of the preserved bone allografts were considered to be deep freezing (-35degC), lyophylization, irradiation, or a combination of lyophylization and irradiation. The latter could be shown to lower the mechanical strength of the bone. Crystal lattice of the bone did not show any alterations in x-ray diffraction pattern, following freeze drying and/or irradiation with doses up to 10 Mrad of gamma radiation. Deterioration in mechanical properties is probably due to damage to the organic phase of the bone matrix

  8. Measurement of the intracellular ph in human stomach cells: a novel approach to evaluate the gastric acid secretory potential of coffee beverages.

    Science.gov (United States)

    Weiss, Carola; Rubach, Malte; Lang, Roman; Seebach, Elisabeth; Blumberg, Simone; Frank, Oliver; Hofmann, Thomas; Somoza, Veronika

    2010-02-10

    As the consumption of coffee beverages sometimes is reported to cause gastric irritation, for which an increased stomach acid secretion is one of the promoting factors, different processing technologies such as steam-treatment have been developed to reduce putative stomach irritating compounds. There is evidence-based data neither on the effect of detailed processing variations nor on individual coffee components affecting the proton secretory activity (PSA). This work aimed at developing a screening model suitable for investigating the effects of commercial coffee beverages and components thereof on human parietal cells. Human gastric cancer cells (HGT-1) were treated with reconstituted freeze-dried coffee beverages prepared from customary coffee products such as regular coffee (RC, n = 4), mild bean coffee (MBC, n = 5), stomach friendly coffee (SFC, n = 4), and SFC decaffeinated (SFCD, n = 3). PSA was analyzed by flow cytometry using the pH-sensitive dye SNARF-AM. Treatment of the cells with MBC did not result in a PSA different from RC treatment (p stomach irritating compounds revealed significantly reduced contents of (beta)N-alkanoyl-5-hydroxytryptamides, caffeine, N-methylpyridinium, and catechol in SFCD compared to RC. However, none of these compounds seem to act as the sole key bioactive reducing the PSA of SFCD, since their contents in MBC and SFC samples were not different from those in RC samples, although the PSA of these beverages was significantly lower than that of reconstituted freeze-dried RC beverage.

  9. Distributions of elements in the human retinal pigment epithelium

    International Nuclear Information System (INIS)

    Ulshafer, R.J.; Allen, C.B.; Rubin, M.L.

    1990-01-01

    Distributions of elements above the atomic number of sodium were mapped in the retinal pigment epithelia of eight human eyes. X-ray energy spectra and maps were collected from cryofixed, freeze-dried, and epoxy-embedded tissues using energy-dispersive x-ray microanalysis. All eyes had high concentrations of phosphorus in the nuclei of retinal pigment epithelial cells. Melanosomes were rich in sulfur, zinc, calcium, and iron. Lipofuscin and cytoplasm contained only phosphorus and sulfur in detectable amounts. Drusen, when present, contained phosphorus and calcium. Six eyes had a prominent aluminum peak recorded from melanosomes, nuclei, and Bruch's membrane. In one pair of 90-year-old eyes, small, electron-dense deposits surrounded many melanosomes and contained mercury and selenium. Retinal pigment epithelial melanosomes may bind and accumulate metals and other potentially toxic ions over time, preventing them from reaching the neural retina

  10. IBA and ICP-OES determination of trace elements in indigenous medicinal herbs and their extracts on the infertility in the human male reproductive system

    Energy Technology Data Exchange (ETDEWEB)

    Mars, J.A.; Fisher, D.; Henkel, R. [Department of Medical Bioscience, Universily of the Weslern Cape, Bellville (South Africa); Weilz, F. [Department of Biodiversily and Conservation Biology, University of the Weslern Cape, Bellville (South Africa)

    2013-07-01

    Full text: The abnormality of infertility in humans is biologically defined (Mader, 2004; Wood, 1994; Ellison, 2001) as the inability of a species to reproduce its own kind after period of 12 month of unprotected sexual intercourse/copulation. It is however difficult when one wishes to quantify the occurrence of infertility, since it is seldom expressed explicitly, but mostly in conjunction with population growth dynamics which include socio-economic factors. Various plants (herbs) have been used as treatment for infertility. These plants however have not yet been scientifically analysed. In this paper we determined the major and trace element composition of Typha capensis (rhizome and leaves) Cissampe/os capensis (Ieaves) and Hermannia cilliata, which were sourced from the Cape Flats Nature Reserve, Bellville, Western Cape Province, South Africa. The trace element concentration determination are at time cumbersome, especially when destructive analytical methods such as ICP-OES are used. For our determination, the various samples were freeze-dried. Part of the freeze-dried sample was used for ICP-OES and the other for PIXE analysis. For PIXE the dried sample was pressed into a pellet, then coated with a layer of carbon and irradiated with a 3 MeV proton beam. We report on the trace element content of the various parts of the plant and comment on the applicability of the part in male infertility. (author)

  11. IBA and ICP-OES determination of trace elements in indigenous medicinal herbs and their extracts on the infertility in the human male reproductive system

    International Nuclear Information System (INIS)

    Mars, J.A.; Fisher, D.; Henkel, R.; Weilz, F.

    2013-01-01

    Full text: The abnormality of infertility in humans is biologically defined (Mader, 2004; Wood, 1994; Ellison, 2001) as the inability of a species to reproduce its own kind after period of 12 month of unprotected sexual intercourse/copulation. It is however difficult when one wishes to quantify the occurrence of infertility, since it is seldom expressed explicitly, but mostly in conjunction with population growth dynamics which include socio-economic factors. Various plants (herbs) have been used as treatment for infertility. These plants however have not yet been scientifically analysed. In this paper we determined the major and trace element composition of Typha capensis (rhizome and leaves) Cissampe/os capensis (Ieaves) and Hermannia cilliata, which were sourced from the Cape Flats Nature Reserve, Bellville, Western Cape Province, South Africa. The trace element concentration determination are at time cumbersome, especially when destructive analytical methods such as ICP-OES are used. For our determination, the various samples were freeze-dried. Part of the freeze-dried sample was used for ICP-OES and the other for PIXE analysis. For PIXE the dried sample was pressed into a pellet, then coated with a layer of carbon and irradiated with a 3 MeV proton beam. We report on the trace element content of the various parts of the plant and comment on the applicability of the part in male infertility. (author)

  12. Determination of mercury in human serum and packed blood cells by neutron activation analysis

    International Nuclear Information System (INIS)

    Versieck, J.; Vanballenberghe, L.; Wittoek, A.; Vermeir, G.; Vandecasteele, C.

    1990-01-01

    A method is described for the determination of mercury in human blood serum and packed blood cells employing neutron activation analysis. Great attention was devoted to the collection and manipulation of the samples. The accuracy and precision of the method were tested by analyzing biological reference materials and by comparing the concentrations measured in a number of serum samples to those obtained by another, independent technique (cold vapor atomic absorption spectrometry) in the same samples. The article reports the levels measured in blood serum and packed blood cells samples from 15 adult volunteers, as well as the figures determined in a open-quotes second-generationclose quotes biological reference material (freeze-dried human serum), prepared and conditioned at the University of Ghent

  13. A Preliminary Study of Human Amniotic Membrane as a Potential Chondrocyte Carrier

    Directory of Open Access Journals (Sweden)

    L Boo

    2009-11-01

    Full Text Available PURPOSE: To investigate the feasibility of using processed human amniotic membrane (HAM to support the attachment and proliferation of chondrocytes in vitro which in turn can be utilised as a cell delivery vehicle in tissue engineering applications. METHODS: Fresh HAM obtained from patients undergoing routine elective caesarean sections was harvested, processed and dried using either freeze drying (FD or air drying (AD methods prior to sterilisation by gamma irradiation. Isolated, processed and characterised rabbit autologous chondrocytes were seeded on processed HAM and cultured for up to three weeks. Cell attachment and proliferation were examined qualitatively using inverted brightfield microscopy. RESULTS: Processed HAM appeared to allow cell attachment when implanted with chondrocytes. Although cells seeded on AD and FD HAM did not appear to attach as strongly as those seeded on glycerol preserved intact human amniotic membrane, these cells to be proliferated in cell culture conditions. CONCLUSION: Preliminary results show that processed HAM promotes chondrocyte attachment and proliferation.