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Sample records for dmsa plga microspheres

  1. Development of Risperidone PLGA Microspheres

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    Susan D’Souza

    2014-01-01

    Full Text Available The aim of this study was to design and evaluate biodegradable PLGA microspheres for sustained delivery of Risperidone, with an eventual goal of avoiding combination therapy for the treatment of schizophrenia. Two PLGA copolymers (50 : 50 and 75 : 25 were used to prepare four microsphere formulations of Risperidone. The microspheres were characterized by several in vitro techniques. In vivo studies in male Sprague-Dawley rats at 20 and 40 mg/kg doses revealed that all formulations exhibited an initial burst followed by sustained release of the active moiety. Additionally, formulations prepared with 50 : 50 PLGA had a shorter duration of action and lower cumulative AUC levels than the 75 : 25 PLGA microspheres. A simulation of multiple dosing at weekly or 15-day regimen revealed pulsatile behavior for all formulations with steady state being achieved by the second dose. Overall, the clinical use of Formulations A, B, C, or D will eliminate the need for combination oral therapy and reduce time to achieve steady state, with a smaller washout period upon cessation of therapy. Results of this study prove the suitability of using PLGA copolymers of varying composition and molecular weight to develop sustained release formulations that can tailor in vivo behavior and enhance pharmacological effectiveness of the drug.

  2. PLGA/alginate composite microspheres for hydrophilic protein delivery

    International Nuclear Information System (INIS)

    Zhai, Peng; Chen, X.B.; Schreyer, David J.

    2015-01-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate. - Highlights: • A double emulsion technique is used to prepare protein-loaded PLGA or PLGA/alginate microspheres. • PLGA, alginate and protein are distributed evenly within microsphere structure. • Addition of alginate improves loading efficiency and slows degradation and protein release. • PLGA/alginate microspheres have favorable biocompatibility

  3. PLGA/alginate composite microspheres for hydrophilic protein delivery

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    Zhai, Peng [Department of Anatomy and Cell Biology, University of Saskatchewan, S7N5E5 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada); Chen, X.B. [Department of Mechanical Engineering, University of Saskatchewan, S7N5A9 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada); Schreyer, David J., E-mail: david.schreyer@usask.ca [Department of Anatomy and Cell Biology, University of Saskatchewan, S7N5E5 (Canada); Division of Biomedical Engineering, University of Saskatchewan, S7N5A9 (Canada)

    2015-11-01

    Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate. - Highlights: • A double emulsion technique is used to prepare protein-loaded PLGA or PLGA/alginate microspheres. • PLGA, alginate and protein are distributed evenly within microsphere structure. • Addition of alginate improves loading efficiency and slows degradation and protein release. • PLGA/alginate microspheres have favorable biocompatibility.

  4. PLGA and PHBV Microsphere Formulations and Solid-State Characterization

    DEFF Research Database (Denmark)

    Yang, Chiming; Plackett, David; Needham, David

    2009-01-01

    To develop and characterize the solid-state properties of poly(DL-lactic-co-glycolic acid) (PLGA) and poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) microspheres for the localized and controlled release of fusidic acid (FA). The effects of FA loading and polymer composition on the me...... of a DCM-FA-rich phase in the forming microsphere....

  5. PEGylated apoptotic protein-loaded PLGA microspheres for cancer therapy

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    Byeon HJ

    2015-01-01

    Full Text Available Hyeong Jun Byeon,1 Insoo Kim,1 Ji Su Choi,1 Eun Seong Lee,2 Beom Soo Shin,3 Yu Seok Youn11Department of Pharmaceutical Sciences, School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea; 2Division of Biotechnology, The Catholic University of Korea, Bucheon-si, Republic of Korea; 3Department of Pharmacy, College of Pharmacy, Catholic University of Daegu, Gyeongsan-si, Republic of KoreaAbstract: The aim of the current study was to investigate the antitumor potential of poly(D,L-lactic-co-glycolic acid microspheres (PLGA MSs containing polyethylene glycol (PEG-conjugated (PEGylated tumor necrosis factor–related apoptosis-inducing ligand (PEG-TRAIL. PEG-TRAIL PLGA MSs were prepared by using a water-in-oil-in-water double-emulsion method, and the apoptotic activities of supernatants released from the PLGA MSs at days 1, 3, and 7 were examined. The antitumor effect caused by PEG-TRAIL PLGA MSs was evaluated in pancreatic Mia Paca-2 cell-xenografted mice. PEG-TRAIL PLGA MS was found to be spherical and 14.4±1.06 µm in size, and its encapsulation efficiency was significantly greater than that of TRAIL MS (85.7%±4.1% vs 43.3%±10.9%, respectively. The PLGA MS gradually released PEG-TRAIL for 14 days, and the released PEG-TRAIL was shown to have clear apoptotic activity in Mia Paca-2 cells, whereas TRAIL released after 1 day had a negligible activity. Finally, PEG-TRAIL PLGA MS displayed remarkably greater antitumor efficacy than blank or TRAIL PLGA MS in Mia Paca-2 cell-xenografted mice in terms of tumor volume and weight, apparently due to increased stability and well-retained apoptotic activity of PEG-TRAIL in PLGA MS. We believe that this PLGA MS system, combined with PEG-TRAIL, should be considered a promising candidate for treating pancreatic cancer.Keywords: Poly(D,L-lactic-co-glycolic acid, controlled release, PEGylation, TRAIL, pancreatic cancer

  6. Controlled Release of Lysozyme from Double-Walled Poly(Lactide-Co-Glycolide (PLGA Microspheres

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    Rezaul H. Ansary

    2017-10-01

    Full Text Available Double-walled microspheres based on poly(lactide-co-glycolide (PLGA are potential delivery systems for reducing a very high initial burst release of encapsulated protein and peptide drugs. In this study, double-walled microspheres made of glucose core, hydroxyl-terminated poly(lactide-co-glycolide (Glu-PLGA, and carboxyl-terminated PLGA were fabricated using a modified water-in-oil-in-oil-in-water (w1/o/o/w2 emulsion solvent evaporation technique for the controlled release of a model protein, lysozyme. Microspheres size, morphology, encapsulation efficiency, lysozyme in vitro release profiles, bioactivity, and structural integrity, were evaluated. Scanning electron microscopy (SEM images revealed that double-walled microspheres comprising of Glu-PLGA and PLGA with a mass ratio of 1:1 have a spherical shape and smooth surfaces. A statistically significant increase in the encapsulation efficiency (82.52% ± 3.28% was achieved when 1% (w/v polyvinyl alcohol (PVA and 2.5% (w/v trehalose were incorporated in the internal and external aqueous phase, respectively, during emulsification. Double-walled microspheres prepared together with excipients (PVA and trehalose showed a better control release of lysozyme. The released lysozyme was fully bioactive, and its structural integrity was slightly affected during microspheres fabrication and in vitro release studies. Therefore, double-walled microspheres made of Glu-PLGA and PLGA together with excipients (PVA and trehalose provide a controlled and sustained release for lysozyme.

  7. A reproducible accelerated in vitro release testing method for PLGA microspheres.

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    Shen, Jie; Lee, Kyulim; Choi, Stephanie; Qu, Wen; Wang, Yan; Burgess, Diane J

    2016-02-10

    The objective of the present study was to develop a discriminatory and reproducible accelerated in vitro release method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro release testing of the prepared risperidone microspheres was performed using the most common in vitro release methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug release compared with less porous microspheres. Both in vitro release methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and accelerated (45 °C) testing conditions. Notably, only the accelerated USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the accelerated USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures). Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Physicochemical characterization of spray-dried PLGA/PEG microspheres, and preliminary assessment of biological response.

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    Javiya, Curie; Jonnalagadda, Sriramakamal

    2016-09-01

    The use of spray-drying to prepare blended PLGA:PEG microspheres with lower immune detection. To study physical properties, polymer miscibility and alveolar macrophage response for blended PLGA:PEG microspheres prepared by a laboratory-scale spray-drying process. Microspheres were prepared by spray-drying 0-20% w/w ratios of PLGA 65:35 and PEG 3350 in dichloromethane. Particle size and morphology was studied using scanning electron microscopy. Polymer miscibility and residual solvent levels evaluated by thermal analysis (differential scanning calorimetry - DSC and thermogravimetric analysis - TGA). Immunogenicity was assessed in vitro by response of rat alveolar macrophages (NR8383) by the MTT-based cell viability assay and reactive oxygen species (ROS) detection. The spray dried particles were spherical, with a size range of about 2-3 µm and a yield of 16-60%. Highest yield was obtained at 1% PEG concentration. Thermal analysis showed a melting peak at 59 °C (enthalpy: 170.61 J/g) and a degradation-onset of 180 °C for PEG 3350. PLGA 65:35 was amorphous, with a Tg of 43 °C. Blended PLGA:PEG microspheres showed a delayed degradation-onset of 280 °C, and PEG enthalpy-loss corresponding to 15% miscibility of PEG in PLGA. NR8383 viability studies and ROS detection upon exposure to these cells suggested that blended PLGA:PEG microspheres containing 1 and 5% PEG are optimal in controling cell proliferation and activation. This research establishes the feasibility of using a spray-drying process to prepare spherical particles (2-3 µm) of molecularly-blended PLGA 65:35 and PEG 3350. A PEG concentration of 1-5% was optimal to maximize process yield, with minimal potential for immune detection.

  9. Active self-healing encapsulation of vaccine antigens in PLGA microspheres

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    Desai, Kashappa-Goud H.; Schwendeman, Steven P.

    2013-01-01

    Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer

  10. Interaction between dimethyldioctadecylammonium bromide-modified PLGA microspheres and hyaluronic acid

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    Mulia, Kamarza; Devi, Krisanti, Elsa

    2017-02-01

    In application of intravitreal injection, an extended drug delivery system is desired so that the frequency of injection to treat diabetic retinopathy may be reduced. Poly(lactic-co-glycolic acid) polymer (PLGA) was used to encapsulate a model drug in the form of microspheres. The zeta potential of dimethyldioctadecylammonium bromide (DDAB)-modified PLGA microspheres in water was proportional to the DDAB concentration used in the preparation step, up to +57.8 mV. The scanning electron microscope pictures and the zeta potential data (SEM) confirmed that the surface of the PLGA has been modified by the cationic surfactant and that electrostatic interaction between the positively charged microspheres and the negatively charged vitreous were present.

  11. Improvement of survival in C6 rat glioma model by a sustained drug release from localized PLGA microspheres in a thermoreversible hydrogel.

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    Ozeki, Tetsuya; Kaneko, Daiki; Hashizawa, Kosuke; Imai, Yoshihiro; Tagami, Tatsuaki; Okada, Hiroaki

    2012-05-10

    A local drug delivery system based on sustained drug release is an attractive approach to treat brain tumors. We have developed a novel device using drug-incorporated poly(lactic-co-glycolic acid) (PLGA) microspheres embedded in thermoreversible gelation polymer (TGP) formulation (drug/PLGA/TGP formulation). TGP forms a gel at body temperature but sol at room temperature. Therefore, when this formulation is injected into the brain tumor, the PLGA microspheres in TGP gel are localized at the injection site and do not diffuse throughout the brain tissue; eventually, sustained drug release from PLGA microspheres is achieved at the target site. In this study, two chemotherapeutic drugs (camptothecin (CPT) or vincristine (VCR)) were incorporated into PLGA microspheres to prepare drug/PLGA/TGP formulations. VCR/PLGA microspheres exhibited the higher encapsulation efficiency than CPT/PLGA microspheres (70.1% versus 30.1%). In addition, VCR/PLGA microspheres showed a higher sustained release profile than CPT/PLGA microspheres (54.5% versus 72.5% release, at 28 days). Therapeutic effect (mean survival) was evaluated in the C6 rat glioma model (control group, 18 days; CPT/PLGA/TGP treatment group, 24 days; VCR/PLGA/TGP treatment group, 33 days). In particular, the VCR/PLGA/TGP formulation produced long-term survivors (>60 days). Therefore, this formulation can be therapeutically effective formulation for the glioma therapy. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Development of Poly Lactic/Glycolic Acid (PLGA Microspheres for Controlled Release of Rho-Associated Kinase Inhibitor

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    Sho Koda

    2017-01-01

    Full Text Available Purpose. The purpose of this study was to investigate the feasibility of poly lactic/glycolic acid (PLGA as a drug delivery carrier of Rho kinase (ROCK inhibitor for the treatment of corneal endothelial disease. Method. ROCK inhibitor Y-27632 and PLGA were dissolved in water with or without gelatin (W1, and a double emulsion [(W1/O/W2] was formed with dichloromethane (O and polyvinyl alcohol (W2. Drug release curve was obtained by evaluating the released Y-27632 by using high performance liquid chromatography. PLGA was injected into the anterior chamber or subconjunctiva in rabbit eyes, and ocular complication was evaluated by slitlamp microscope and histological analysis. Results. Y-27632 incorporated PLGA microspheres with different molecular weights, and different composition ratios of lactic acid and glycolic acid were fabricated. A high molecular weight and low content of glycolic acid produced a slower and longer release. The Y-27632 released from PLGA microspheres significantly promoted the cell proliferation of cultured corneal endothelial cells. The injection of PLGA did not induce any evident eye complication. Conclusions. ROCK inhibitor-incorporated PLGA microspheres were fabricated, and the microspheres achieved the sustained release of ROCK inhibitor over 7–10 days in vitro. Our data should encourage researchers to use PLGA microspheres for treating corneal endothelial diseases.

  13. Development of andrographolide loaded PLGA microspheres: optimization, characterization and in vitro-in vivo correlation.

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    Jiang, Yunxia; Wang, Fang; Xu, Hui; Liu, Hui; Meng, Qingguo; Liu, Wanhui

    2014-11-20

    The purpose of this study was to develop a sustained-release drug delivery system based on the injectable PLGA microspheres loaded with andrographolide. The andrographolide loaded PLGA microspheres were prepared by emulsion solvent evaporation method with optimization of formulation using response surface methodology (RSM). Physicochemical characterization, in vitro release behavior and in vivo pharmacokinetics of the optimized formulation were then evaluated. The percent absorbed in vivo was determined by deconvolution using the Loo-Riegelman method, and then the in vitro-in vivo correlation (IVIVC) was established. Results showed that the microspheres were spherical with a smooth surface. Average particle size, entrapment efficiency and drug loading were found to be 53.18±2.11 μm, 75.79±3.02% and 47.06±2.18%, respectively. In vitro release study showed a low initial burst release followed by a prolonged release up to 9 days and the release kinetics followed the Korsmeyer-Peppas model. After a single intramuscular injection, the microspheres maintained relatively high plasma concentration of andrographolide over one week. A good linear relationship was observed between the in vitro and in vivo release behavior (R(2)=0.9951). These results suggest the PLGA microspheres could be developed as a potential delivery system for andrographolide with high drug loading capacity and sustained drug release. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Poly(d,l)-lactide-co-glycolide (PLGA) microspheres as immunoadjuvant for Brugia malayi antigens.

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    Saini, Vinay; Verma, Shiv Kumar; Murthy, P Kalpana; Kohli, Dharmveer

    2013-08-28

    Recently we identified in Brugia malayi adult worm extract (BmA) a pro-inflammatory 54-68kDa SDS-PAGE resolved fraction F6 that protects the host from the parasite via Th1/Th2 type responses. We are currently investigating F6 as a potential source of vaccine candidate(s) and the present study is aimed at investigating the suitability of poly(d,l)-lactide-co-glycolide microspheres (PLGA-Ms) as immunoadjuvant for the antigen administration in a single dose. PLGA-Ms were prepared aseptically by a modified double emulsion (w/o/w) solvent evaporation technique and their size, shape, antigen adsorption efficiency, in-process stability, and antigen release were characterized. Swiss mice were immunized by a single subcutaneous administration of BmA and F6 adsorbed on PLGA-Ms (lactide:glycolide ratios 50:50 and 75:25) and the immune responses were compared with administration of 1 or 2 doses of plain BmA and F6. Specific IgG, IgG1, IgG2a, IgG2b, IgE levels in serum, cellular-proliferative response and release of IFN-γ, TNF-α and nitric oxide from the cells of immunized host in response to the antigens/LPS/Con A challenge and antibody-dependant cellular cytotoxicity (ADCC) to parasite life stages were determined. The average size of PLGA-Ms 50:50 was smaller than the size of PLGA-Ms 75:25 and the % antigen adsorption efficiency of PLGA-Ms 50:50 was greater than PLGA-Ms 75:25. Single shot injection of PLGA-Ms 50:50/75:25-BmA/F6 produced better and stronger IgG, IgG1/IgG2a and cell-mediated immune responses than even two injections of plain BmA or F6. Further, PLGA-Ms 50:50-F6 produced stronger responses than PLGA-Ms 50:50-BmA. Anti-PLGA-Ms 50:50-F6 antibodies elicited higher ADCC response to infective larval and microfilarial stages of the parasite than anti-PLGA-Ms 75:25-F6 antibodies. The findings demonstrate that PLGA-Ms 50:50 is an excellent adjuvant for use with F6 in a single administration. This is the first ever report on PLGA as immunoadjuvant for filarial antigens

  15. Sustained release donepezil loaded PLGA microspheres for injection: Preparation, in vitro and in vivo study

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    Wenjia Guo

    2015-10-01

    Full Text Available The purpose of this study was to develop a PLGA microspheres-based donepezil (DP formulation which was expected to sustain release of DP for one week with high encapsulation efficiency (EE. DP derived from donepezil hydrochloride was encapsulated in PLGA microspheres by the O/W emulsion-solvent evaporation method. The optimized formulation which avoided the crushing of microspheres during the preparation process was characterized in terms of particle size, morphology, drug loading and EE, physical state of DP in the matrix and in vitro and in vivo release behavior. DP microspheres were prepared successfully with average diameter of 30 µm, drug loading of 15.92 ± 0.31% and EE up to 78.79 ± 2.56%. Scanning electron microscope image showed it has integrated spherical shape with no drug crystal and porous on its surface. Differential scanning calorimetry and X-ray diffraction results suggested DP was in amorphous state or molecularly dispersed in microspheres. The Tg of PLGA was increased with the addition of DP. The release profile in vitro was characterized with slow but continuous release that lasted for about one week and fitted well with first-order model, which suggested the diffusion governing release mechanism. After single-dose administration of DP microspheres via subcutaneous injection in rats, the plasma concentration of DP reached peak concentration at 0.50 d, and then declined gradually, but was still detectable at 15 d. A good correlation between in vitro and in vivo data was obtained. The results suggest the potential use of DP microspheres for treatment of Alzheimer's disease over long periods.

  16. Fabrication and evaluation of a sustained-release chitosan-based scaffold embedded with PLGA microspheres

    International Nuclear Information System (INIS)

    Song, Kedong; Liu, Yingchao; Macedo, Hugo M.; Jiang, Lili; Li, Chao; Mei, Guanyu; Liu, Tianqing

    2013-01-01

    Nutrient depletion within three-dimensional (3D) scaffolds is one of the major hurdles in the use of this technology to grow cells for applications in tissue engineering. In order to help in addressing it, we herein propose to use the controlled release of encapsulated nutrients within polymer microspheres into chitosan-based 3D scaffolds, wherein the microspheres are embedded. This method has allowed maintaining a stable concentration of nutrients within the scaffolds over the long term. The polymer microspheres were prepared using multiple emulsions (w/o/w), in which bovine serum albumin (BSA) and poly (lactic-co-glycolic) acid (PLGA) were regarded as the protein pattern and the exoperidium material, respectively. These were then mixed with a chitosan solution in order to form the scaffolds by cryo-desiccation. The release of BSA, entrapped within the embedded microspheres, was monitored with time using a BCA kit. The morphology and structure of the PLGA microspheres containing BSA before and after embedding within the scaffold were observed under a scanning electron microscope (SEM). These had a round shape with diameters in the range of 27–55 μm, whereas the chitosan-based scaffolds had a uniform porous structure with the microspheres uniformly dispersed within their 3D structure and without any morphological change. In addition, the porosity, water absorption and degradation rate at 37 °C in an aqueous environment of 1% chitosan-based scaffolds were (92.99 ± 2.51) %, (89.66 ± 0.66) % and (73.77 ± 3.21) %, respectively. The studies of BSA release from the embedded microspheres have shown a sustained and cumulative tendency with little initial burst, with (20.24 ± 0.83) % of the initial amount released after 168 h (an average rate of 0.12%/h). The protein concentration within the chitosan-based scaffolds after 168 h was found to be (11.44 ± 1.81) × 10 −2 mg/mL. This novel chitosan-based scaffold embedded with PLGA microspheres has proven to be a

  17. Fabrication and evaluation of a sustained-release chitosan-based scaffold embedded with PLGA microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kedong, E-mail: kedongsong@dlut.edu.cn [Dalian R and D Center for Stem Cell and Tissue Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Liu, Yingchao [Dalian R and D Center for Stem Cell and Tissue Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Macedo, Hugo M. [Biological Systems Engineering Laboratory, Department of Chemical Engineering, Department of Chemical Engineering, South Kensington Campus, London SW7 2AZ (United Kingdom); Jiang, Lili; Li, Chao; Mei, Guanyu [Dalian R and D Center for Stem Cell and Tissue Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Liu, Tianqing, E-mail: liutq@dlut.edu.cn [Dalian R and D Center for Stem Cell and Tissue Engineering, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

    2013-04-01

    Nutrient depletion within three-dimensional (3D) scaffolds is one of the major hurdles in the use of this technology to grow cells for applications in tissue engineering. In order to help in addressing it, we herein propose to use the controlled release of encapsulated nutrients within polymer microspheres into chitosan-based 3D scaffolds, wherein the microspheres are embedded. This method has allowed maintaining a stable concentration of nutrients within the scaffolds over the long term. The polymer microspheres were prepared using multiple emulsions (w/o/w), in which bovine serum albumin (BSA) and poly (lactic-co-glycolic) acid (PLGA) were regarded as the protein pattern and the exoperidium material, respectively. These were then mixed with a chitosan solution in order to form the scaffolds by cryo-desiccation. The release of BSA, entrapped within the embedded microspheres, was monitored with time using a BCA kit. The morphology and structure of the PLGA microspheres containing BSA before and after embedding within the scaffold were observed under a scanning electron microscope (SEM). These had a round shape with diameters in the range of 27–55 μm, whereas the chitosan-based scaffolds had a uniform porous structure with the microspheres uniformly dispersed within their 3D structure and without any morphological change. In addition, the porosity, water absorption and degradation rate at 37 °C in an aqueous environment of 1% chitosan-based scaffolds were (92.99 ± 2.51) %, (89.66 ± 0.66) % and (73.77 ± 3.21) %, respectively. The studies of BSA release from the embedded microspheres have shown a sustained and cumulative tendency with little initial burst, with (20.24 ± 0.83) % of the initial amount released after 168 h (an average rate of 0.12%/h). The protein concentration within the chitosan-based scaffolds after 168 h was found to be (11.44 ± 1.81) × 10{sup −2} mg/mL. This novel chitosan-based scaffold embedded with PLGA microspheres has proven to be a

  18. [Construction and evaluation of the tissue engineered nerve of bFGF-PLGA sustained release microspheres].

    Science.gov (United States)

    Wang, Guanglin; Lin, Wei; Gao, Weiqiang; Xiao, Yuhua; Dong, Changchao

    2008-12-01

    To study the outcomes of nerve defect repair with the tissue engineered nerve, which is composed of the complex of SCs, 30% ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeable poly (D, L-lactic acid) (PDLLA) catheters. SCs were cultured and purified from the sciatic nerves of 1-day-old neonatal SD rats. The 1st passage cells were compounded with bFGF-PLGA sustained release microspheres and ECM gel, and then were injected into permeable PDLLA catheters with PLGA microfilaments inside. In this way, the tissue engineered nerve was constructed. Sixty SD rats were included. The model of 15-mm sciatic nerve defects was made, and then the rats were randomly divided into 5 groups, with 12 rats in each. In group A, autograft was adopted. In group B, the blank PDLLA catheters with PBS inside were used. In group C, PDLLA catheters, with PLGA microfilaments and 30% ECM gel inside, were used. In group D, PDLLA catheters, with PLGA microfilaments, SCs and 30% ECM gel inside, were used. In group E, the tissue engineered nerve was applied. After the operation, observation was made for general conditions of the rats. The sciatic function index (SFI) analysis was performed at 12, 16, 20 and 24 weeks after the operation, respectively. Electrophysiological detection and histological observation were performed at 12 and 24 weeks after the operation, respectively. All rats survived to the end of the experiment. At 12 and 16 weeks after the operation, group E was significantly different from group B in SFI (P fibers in group E were significantly differents from those in groups A, B and C (P fibers in group E were smaller than those in group A (P fibers in group E was significantly different from those in groups A, B, C (P fibers in group E were bigger than those in groups B and C (P < 0.05). The tissue engineered nerve with the complex of SCs, ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeable PDLLA catheters promote

  19. Collagen/silk fibroin composite scaffold incorporated with PLGA microsphere for cartilage repair

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianhua; Yang, Qiu; Cheng, Niangmei [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Tao, Xiaojun [Department of Pharmacy, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan (China); Zhang, Zhihua; Sun, Xiaomin [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Zhang, Qiqing, E-mail: zhangqiq@126.com [Institute of Biomedical and Pharmaceutical Technology, Fuzhou University, Fuzhou 350002 (China); Key Laboratory of Biomedical Materials of Tianjin, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin 300192 (China)

    2016-04-01

    For cartilage repair, ideal scaffolds should mimic natural extracellular matrix (ECM) exhibiting excellent characteristics, such as biocompatibility, suitable porosity, and good cell affinity. This study aimed to prepare a collagen/silk fibroin composite scaffold incorporated with poly-lactic-co-glycolic acid (PLGA) microsphere that can be applied in repairing cartilage. To obtain optimum conditions for manufacturing a composite scaffold, a scaffold composed of different collagen-to-silk fibroin ratios was evaluated by determining porosity, water absorption, loss rate in hot water, and cell proliferation. Results suggested that the optimal ratio of collagen and silk fibroin composite scaffold was 7:3. The microstructure and morphological characteristics of the obtained scaffold were also examined through scanning electron microscopy and Fourier transform infrared spectroscopy. The results of in vitro fluorescence staining of bone marrow stromal cells revealed that collagen/silk fibroin composite scaffold enhanced cell proliferation without eliciting side effects. The prepared composite scaffold incorporated with PLGA microsphere was implanted in fully thick articular cartilage defects in rabbits. Collagen/silk fibroin composite scaffold with PLGA microspheres could enhance articular cartilage regeneration and integration between the repaired cartilage and the surrounding cartilage. Therefore, this composite will be a promising material for cartilage repair and regeneration. - Highlights: • Collagen/silk fibroin composite scaffold incorporated with PLGA microsphere proposed for cartilage repair was created. • In vivo, scaffold could enhance cartilage regeneration and integration between the repaired and surrounding cartilage. • In vitro, scaffold exhibits excellent characteristics, such as, improved porosity water absorption and good cell affinity.

  20. Fabrication and evaluation of a sustained-release chitosan-based scaffold embedded with PLGA microspheres.

    Science.gov (United States)

    Song, Kedong; Liu, Yingchao; Macedo, Hugo M; Jiang, Lili; Li, Chao; Mei, Guanyu; Liu, Tianqing

    2013-04-01

    Nutrient depletion within three-dimensional (3D) scaffolds is one of the major hurdles in the use of this technology to grow cells for applications in tissue engineering. In order to help in addressing it, we herein propose to use the controlled release of encapsulated nutrients within polymer microspheres into chitosan-based 3D scaffolds, wherein the microspheres are embedded. This method has allowed maintaining a stable concentration of nutrients within the scaffolds over the long term. The polymer microspheres were prepared using multiple emulsions (w/o/w), in which bovine serum albumin (BSA) and poly (lactic-co-glycolic) acid (PLGA) were regarded as the protein pattern and the exoperidium material, respectively. These were then mixed with a chitosan solution in order to form the scaffolds by cryo-desiccation. The release of BSA, entrapped within the embedded microspheres, was monitored with time using a BCA kit. The morphology and structure of the PLGA microspheres containing BSA before and after embedding within the scaffold were observed under a scanning electron microscope (SEM). These had a round shape with diameters in the range of 27-55 μm, whereas the chitosan-based scaffolds had a uniform porous structure with the microspheres uniformly dispersed within their 3D structure and without any morphological change. In addition, the porosity, water absorption and degradation rate at 37 °C in an aqueous environment of 1% chitosan-based scaffolds were (92.99±2.51) %, (89.66±0.66) % and (73.77±3.21) %, respectively. The studies of BSA release from the embedded microspheres have shown a sustained and cumulative tendency with little initial burst, with (20.24±0.83) % of the initial amount released after 168 h (an average rate of 0.12%/h). The protein concentration within the chitosan-based scaffolds after 168 h was found to be (11.44±1.81)×10(-2) mg/mL. This novel chitosan-based scaffold embedded with PLGA microspheres has proven to be a promising technique

  1. Electrospray synthesis and properties of hierarchically structured PLGA TIPS microspheres for use as controlled release technologies.

    Science.gov (United States)

    Malik, Salman A; Ng, Wing H; Bowen, James; Tang, Justin; Gomez, Alessandro; Kenyon, Anthony J; Day, Richard M

    2016-04-01

    Microsphere-based controlled release technologies have been utilized for the long-term delivery of proteins, peptides and antibiotics, although their synthesis poses substantial challenges owing to formulation complexities, lack of scalability, and cost. To address these shortcomings, we used the electrospray process as a reproducible, synthesis technique to manufacture highly porous (>94%) microspheres while maintaining control over particle structure and size. Here we report a successful formulation recipe used to generate spherical poly(lactic-co-glycolic) acid (PLGA) microspheres using the electrospray (ES) coupled with a novel thermally induced phase separation (TIPS) process with a tailored Liquid Nitrogen (LN2) collection scheme. We show how size, shape and porosity of resulting microspheres can be controlled by judiciously varying electrospray processing parameters and we demonstrate examples in which the particle size (and porosity) affect release kinetics. The effect of electrospray treatment on the particles and their physicochemical properties are characterized by scanning electron microscopy, confocal Raman microscopy, thermogravimetric analysis and mercury intrusion porosimetry. The microspheres manufactured here have successfully demonstrated long-term delivery (i.e. 1week) of an active agent, enabling sustained release of a dye with minimal physical degradation and have verified the potential of scalable electrospray technologies for an innovative TIPS-based microsphere production protocol. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Core/shell PLGA microspheres with controllable in vivo release profile via rational core phase design.

    Science.gov (United States)

    Yu, Meiling; Yao, Qing; Zhang, Yan; Chen, Huilin; He, Haibing; Zhang, Yu; Yin, Tian; Tang, Xing; Xu, Hui

    2018-02-27

    Highly soluble drugs tend to release from preparations at high speeds, which make them need to be taken at frequent intervals. Additionally, some drugs need to be controlled to release in vivo at certain periods, so as to achieve therapeutic effects. Thus, the objective of this study is to design injectable microparticulate systems with controllable in vivo release profile. Biodegradable PLGA was used as the matrix material to fabricate microspheres using the traditional double emulsification-solvent evaporation method as well as improved techniques, with gel (5% gelatine or 25% F127) or LP powders as the inner phases. Their physicochemical properties were systemically investigated. Microspheres prepared by modified methods had an increase in drug loading (15.50, 16.72, 15.66%, respectively) and encapsulation efficiencies (73.46, 79.42, 74.40%, respectively) when compared with traditional methods (12.01 and 57.06%). The morphology of the particles was characterized by optical microscope (OM) and scanning electron microscopy (SEM), and the amorphous nature of the encapsulated drug was confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis. To evaluate their release behaviour, the in vitro degradation, in vitro release and in vivo pharmacodynamics were subsequently studied. Traditional microspheres prepared in this study with water as the inner phase had a relatively short release period within 16 d when compared with modified microspheres with 5% gelatine as the inner phase, which resulted in a smooth release profile and appropriate plasma LP concentrations over 21 d. Thus this type of modified microspheres can be better used in drugs requiring sustained release. The other two formulations containing 25% F127 and LP micropowders presented two-stage release profiles, resulting in fluctuant plasma LP concentrations which may be suitable for drugs requiring controlled release. All the results suggested that drug release rates from

  3. Accelerated in vitro release testing of implantable PLGA microsphere/PVA hydrogel composite coatings.

    Science.gov (United States)

    Shen, Jie; Burgess, Diane J

    2012-01-17

    Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, accelerated in vitro release testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug release kinetics were investigated under "real-time" and accelerated conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to "real-time" conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order release phase was slightly accelerated. Elevated temperatures resulted in a significant acceleration of dexamethasone release. The accelerated release data were able to predict "real-time" release when applying the Arrhenius equation. Microsphere batches with faster and slower release profiles were investigated under "real-time" and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro release testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Development of a novel AMX-loaded PLGA/zein microsphere for root canal disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, F F O [Capes Foundation, Ministry of Education of Brazil, Cx. Postal 365, BrasIlia DF 70359-970 (Brazil); Luzardo-Alvarez, A; Blanco-Mendez, J [Department of Pharmacy and Pharmaceutical Technology, School of Pharmacy, University of Santiago de Compostela, Campus Universitario Sur s/n, 15782, Santiago de Compostela (Spain); Perez-Estevez, A; Seoane-Prado, R, E-mail: franciscofabio.oliveira@rai.usc.e [Departament of Microbiology and Parasitology, Medical School, University of Santiago de Compostela, R/de San Francisco, s/n, 15782, Santiago de Compostela (Spain)

    2010-10-01

    The aim of this study was to develop polymeric biodegradable microspheres (MSs) of poly(d-l lactide-co-glycolide) (PLGA) and zein capable of delivering amoxicillin (AMX) at significant levels for root canal disinfection. PLGA/zein MSs were prepared using a spray-drying technique. The systems were characterized in terms of particle size, morphology, drug loading and in vitro release. Drug levels were reached to be effective during the intracanal dressing in between visits during the endodontic treatment. In vitro release studies were carried out to understand the release profile of the MSs. Antimicrobial activity of AMX was performed by antibiograms. Enterococcus faecalis was the bacteria selected due to its prevalence in endodontic failure. Drug microencapsulation yielded MSs with spherical morphology and an average particle size of between 5 and 38 {mu}m. Different drug-release patterns were obtained among the formulations. Release features related to the MSs were strongly dependent on drug nature as it was demonstrated by using a hydrophobic drug (indomethacin). Finally, AMX-loaded MSs were efficient against E faecalis as demonstrated by the antibiogram results. In conclusion, PLGA/zein MSs prepared by spray drying may be a useful drug delivery system for root canal disinfection.

  5. Development of a novel AMX-loaded PLGA/zein microsphere for root canal disinfection

    International Nuclear Information System (INIS)

    Sousa, F F O; Luzardo-Alvarez, A; Blanco-Mendez, J; Perez-Estevez, A; Seoane-Prado, R

    2010-01-01

    The aim of this study was to develop polymeric biodegradable microspheres (MSs) of poly(d-l lactide-co-glycolide) (PLGA) and zein capable of delivering amoxicillin (AMX) at significant levels for root canal disinfection. PLGA/zein MSs were prepared using a spray-drying technique. The systems were characterized in terms of particle size, morphology, drug loading and in vitro release. Drug levels were reached to be effective during the intracanal dressing in between visits during the endodontic treatment. In vitro release studies were carried out to understand the release profile of the MSs. Antimicrobial activity of AMX was performed by antibiograms. Enterococcus faecalis was the bacteria selected due to its prevalence in endodontic failure. Drug microencapsulation yielded MSs with spherical morphology and an average particle size of between 5 and 38 μm. Different drug-release patterns were obtained among the formulations. Release features related to the MSs were strongly dependent on drug nature as it was demonstrated by using a hydrophobic drug (indomethacin). Finally, AMX-loaded MSs were efficient against E faecalis as demonstrated by the antibiogram results. In conclusion, PLGA/zein MSs prepared by spray drying may be a useful drug delivery system for root canal disinfection.

  6. Strategies for encapsulation of small hydrophilic and amphiphilic drugs in PLGA microspheres: State-of-the-art and challenges

    NARCIS (Netherlands)

    Ramazani, F.; Chen, Weiluan; van Nostrum, C.F.; Storm, Gerrit; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria; Hennink, W.E.; Kok, R.J.

    2016-01-01

    Poly(lactide-co-glycolide) (PLGA) microspheres are efficient delivery systems for controlled release of low molecular weight drugs as well as therapeutic macromolecules. The most common microencapsulation methods are based on emulsification procedures, in which emulsified droplets of polymer and

  7. Effect of WOW process parameters on morphology and burst release of FITC-dextran loaded PLGA microspheres.

    Science.gov (United States)

    Mao, Shirui; Xu, Jing; Cai, Cuifang; Germershaus, Oliver; Schaper, Andreas; Kissel, Thomas

    2007-04-04

    Using fluorescein isothiocyanate labeled dextran (FITC-dextran 40, FD40) as a hydrophilic model compound, microspheres were prepared by a WOW double emulsion technique. Influence of process parameters on microsphere morphology and burst release of FD40 from PLGA microspheres was studied. Internal morphology of microspheres was investigated by stereological method via cryo-cutting technique and scanning electron microscopy (SEM). Drug distribution in microspheres was observed with confocal laser scanning microscopy (CLSM). Polymer nature (RG503 and RG503H) had significant influence on the micro-morphology of microspheres. Increase in continuous water phase volume (W2) led to increased surface porosity but decreased internal porosity. By increasing PVA concentration in the continuous phase from 0.1 to 1%, particle size changed marginally but burst release decreased from 12.2 to 5.9%. Internal porosity of microspheres decreased considerably with increasing polymer concentration. Increase in homogenization speed during the primary emulsion preparation led to decreased internal porosity. Burst release decreased with increasing drug loading but increased with drug molecular weight. Drug distribution in microspheres depended on preparation method. The porosity of microspheres decreased with time in the diffusion stage, but internal morphology had no influence on the release behavior in the bioerosion stage. In summary, surface porosity and internal morphology play a significant role in the release of hydrophilic macromolecules from biodegradable microspheres in the initial release phase characterized by pore diffusion.

  8. Accelerated in vitro release testing method for naltrexone loaded PLGA microspheres.

    Science.gov (United States)

    Andhariya, Janki V; Choi, Stephanie; Wang, Yan; Zou, Yuan; Burgess, Diane J; Shen, Jie

    2017-03-30

    The objective of the present study was to develop a discriminatory and reproducible accelerated release testing method for naltrexone loaded parenteral polymeric microspheres. The commercially available naltrexone microsphere product (Vivitrol ® ) was used as the testing formulation in the in vitro release method development, and both sample-and-separate and USP apparatus 4 methods were investigated. Following an in vitro drug stability study, frequent media replacement and addition of anti-oxidant in the release medium were used to prevent degradation of naltrexone during release testing at "real-time" (37°C) and "accelerated" (45°C), respectively. The USP apparatus 4 method was more reproducible than the sample-and-separate method. In addition, the accelerated release profile obtained using USP apparatus 4 had a shortened release duration (within seven days), and good correlation with the "real-time" release profile. Lastly, the discriminatory ability of the developed accelerated release method was assessed using compositionally equivalent naltrexone microspheres with different release characteristics. The developed accelerated USP apparatus 4 release method was able to detect differences in the release characteristics of the prepared naltrexone microspheres. Moreover, a linear correlation was observed between the "real-time" and accelerated release profiles of all the formulations investigated, suggesting that the release mechanism(s) may be similar under both conditions. These results indicate that the developed accelerated USP apparatus 4 method has the potential to be an appropriate fast quality control tool for long-acting naltrexone PLGA microspheres. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Preparation of a reproducible long-acting formulation of risperidone-loaded PLGA microspheres using microfluidic method.

    Science.gov (United States)

    Jafarifar, Elham; Hajialyani, Marziyeh; Akbari, Mona; Rahimi, Masoud; Shokoohinia, Yalda; Fattahi, Ali

    2017-09-01

    The aim of the present study is to prepare risperidone-loaded poly lactic-co-glycolic acid (PLGA) microspheres within microfluidic system and to achieve a formulation with uniform size and monotonic and reproducible release profile. In comparison to batch method, T-junction and serpentine chips were utilized and optimizing study was carried out at different processing parameters (e.g. PLGA and surfactant concentration and flow rates ratio of outer to inner phase). The computational fluid dynamic (CFD) modeling was performed, and loading and release study were carried out. CFD simulation indicates that increasing the flow rate of aqueous phase cause to decrease the droplet size, while the change in size of microspheres did not follow a specific pattern in the experimental results. The most uniform microspheres and narrowest standard deviation (66.79 μm ± 3.32) were achieved using T-junction chip, 1% polyvinylalcohol, 1% PLGA and flow rates ratio of 20. The microfluidic-assisted microspheres were more uniform with narrower size distribution. The release of risperidone from microspheres produced by the microfluidic method was more reproducible and closer to zero-order kinetic model. The release profile of formulation with 2:1 drug-to-polymer ratio was the most favorable release, in which 41.85% release could be achieved during 24 days.

  10. Release of a wound-healing agent from PLGA microspheres in a thermosensitive gel.

    Science.gov (United States)

    Machado, H A; Abercrombie, J J; You, T; Deluca, P P; Leung, K P

    2013-01-01

    The purpose of this research was to develop a topical microsphere delivery system in a thermosensitive 20% poloxamer 407 gel (Pluronic F127) to control release of KSL-W, a cationic antimicrobial decapeptide, for a period of 4-7 days for potential application in combat related injuries. KSL-W loaded microsphere formulations were prepared by a solvent extraction-evaporation method (water-oil-water), with poly (D,L-lactic-co-glycolic acid) (PLGA) (50 : 50, low-weight, and hydrophilic end) as the polymeric system. After optimization of the process, three formulations (A, B, and C) were prepared with different organic to water ratio of the primary emulsion while maintaining other components and manufacturing parameters constant. Formulations were characterized for surface morphology, porous nature, drug loading, in vitro drug release, and antimicrobial activity. Microspheres containing 20% peptide with porous surfaces and internal structure were prepared in satisfactory yields and in sizes varying from 25 to 50 μm. Gels of 20% Pluronic F127, which were liquid at or below 24.6°C and formed transparent films at body temperature, were used as carriers for the microspheres. Rheological studies showed a gelation temperature of 24.6°C for the 20% Pluronic F127 gel alone. Gelation temperature and viscosity of formulations A, B, and C as a function of temperature were very close to those of the carrier. A Franz diffusion cell system was used to study the release of peptide from the microspheres suspended in both, phosphate-buffered saline (PBS) and a 20% Pluronic F127 gel. In vitro release of greater than 50% peptide was found in all formulations in both PBS and the gel, and in one formulation there was a release of 75% in both PBS and the gel. Fractions collected from the release process were also tested for bactericidal activity against Staphylococcus epidermidis using the broth microdilution method and found to provide effective antimicrobial activity to warrant

  11. In vitro and in vivo evaluation of calcium phosphate composite scaffolds containing BMP-VEGF loaded PLGA microspheres for the treatment of avascular necrosis of the femoral head.

    Science.gov (United States)

    Zhang, Hao-Xuan; Zhang, Xiu-Ping; Xiao, Gui-Yong; Hou, Yong; Cheng, Lei; Si, Meng; Wang, Shuai-Shuai; Li, Yu-Hua; Nie, Lin

    2016-03-01

    Avascular necrosis of the femoral head (ANFH) is difficult to treat due to high pressure and hypoxia, and reduced levels of growth factors such as bone morphogenetic protein (BMP), and vascular endothelial growth factor (VEGF). We generated a novel calcium phosphate (CPC) composite scaffold, which contains BMP-VEGF-loaded poly-lactic-co-glycolic acid (PLGA) microspheres (BMP-VEGF-PLGA-CPC). The BMP-VEGF-loaded microspheres have an encapsulation efficiency of 89.15% for BMP, and 78.55% for VEGF. The BMP-VEGF-PLGA-CPC scaffold also demonstrated a porosity of 62% with interconnected porous structures, and pore sizes of 219 μm and compressive strength of 6.60 MPa. Additionally, bone marrow mesenchymal stem cells (BMSCs) were seeded on scaffolds in vitro. Further characterization showed that the BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. Using a rabbit model of ANFH, BMP-VEGF-PLGA-CPC scaffolds were implanted into the bone tunnels of core decompression in the femoral head for 6 and 12 weeks. Radiographic and histological analysis demonstrated that the BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. These results indicate that the BMP-VEGF-PLGA-CPC scaffold may improve the therapeutic effect of core decompression surgery and be used as a treatment for ANFH. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Preparation and in vitro and in vivo evaluation of HupA PLGA microsphere.

    Science.gov (United States)

    Ye, Liang; Fu, Fenghua; Liu, Wanhui; Sun, Kaoxiang; Li, Youxin; He, Jie; Yu, Xin; Yu, Pengfei; Tian, Jingwei

    2013-03-01

    Acetylcholinesterase inhibitors (AChEIs), including Huperzine A (HupA), have been the mainstay of treatment for Alzheimer's disease (AD). However, AChEIs can cause gastrointestinal side effects, which has been related to the high Cmax and short tmax after oral administration. Clinical trials have verified that extended-release formulation with lower Cmax and prolonged tmax, such as rivastigmine patch, could perform a similar efficacy with significantly improved tolerability compared with the oral formulations. In this study, we developed an extended-release microspheres formulation of HupA (called as HAM) with poly(lactide-co-glycolide) (PLGA) as drug carrier. HAM has showed the loading rate as 1.35% (w/w) and yielded 42% with mean particle size at 72.6 μm. In vitro and in vivo pharmacokinetics studies have showed that HAM produced a relatively smooth and continuous drug concentration in 14 days. Furthermore, in vivo pharmacokinetics data have demonstrated that the Cmax was lower and the tmax was considerably later in single intramuscular administration of HAM (1,000 μg/kg) than the counterparts in single intragastric administration of HAT (75 μg/kg/d). Meanwhile, HAM has performed a continuous inhibition to brain AChE activity in normal rats and improvement of memory deficit in Aβ1-40 i.c.v. infused AD rat model for 14 days. The results have suggested that HAM has performed good extended-release properties and good prolonged pharmacological efficacy in vivo in the 2-week period, and could exert a similar efficacy with significantly lowered gastrointestinal side effects as compared with oral formulation.

  13. In vitro and in vivo evaluation of calcium phosphate composite scaffolds containing BMP-VEGF loaded PLGA microspheres for the treatment of avascular necrosis of the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao-Xuan [Department of Orthopedics, Shandong University Qilu Hospital, Jinan, Shandong (China); Zhang, Xiu-Ping [School of Public Health, Fudan University, Shanghai (China); Xiao, Gui-Yong [School of Materials Science and Engineering, Shandong University, Jinan, Shandong (China); Key Laboratory for Liquid–Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan, Shandong (China); Hou, Yong; Cheng, Lei; Si, Meng; Wang, Shuai-Shuai [Department of Orthopedics, Shandong University Qilu Hospital, Jinan, Shandong (China); Li, Yu-Hua, E-mail: qiluyuhua@126.com [Department of Orthopedics, Shandong University Qilu Hospital, Jinan, Shandong (China); Nie, Lin, E-mail: hoho05@126.com [Department of Orthopedics, Shandong University Qilu Hospital, Jinan, Shandong (China)

    2016-03-01

    Avascular necrosis of the femoral head (ANFH) is difficult to treat due to high pressure and hypoxia, and reduced levels of growth factors such as bone morphogenetic protein (BMP), and vascular endothelial growth factor (VEGF). We generated a novel calcium phosphate (CPC) composite scaffold, which contains BMP-VEGF-loaded poly-lactic-co-glycolic acid (PLGA) microspheres (BMP-VEGF-PLGA-CPC). The BMP-VEGF-loaded microspheres have an encapsulation efficiency of 89.15% for BMP, and 78.55% for VEGF. The BMP-VEGF-PLGA-CPC scaffold also demonstrated a porosity of 62% with interconnected porous structures, and pore sizes of 219 μm and compressive strength of 6.60 MPa. Additionally, bone marrow mesenchymal stem cells (BMSCs) were seeded on scaffolds in vitro. Further characterization showed that the BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. Using a rabbit model of ANFH, BMP-VEGF-PLGA-CPC scaffolds were implanted into the bone tunnels of core decompression in the femoral head for 6 and 12 weeks. Radiographic and histological analysis demonstrated that the BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. These results indicate that the BMP-VEGF-PLGA-CPC scaffold may improve the therapeutic effect of core decompression surgery and be used as a treatment for ANFH. - Highlights: • BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. • BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. • BMP-VEGF-PLGA-CPC scaffolds provided a new approach for the treatment of avascular necrosis of the femoral head (ANFH).

  14. In vitro and in vivo evaluation of calcium phosphate composite scaffolds containing BMP-VEGF loaded PLGA microspheres for the treatment of avascular necrosis of the femoral head

    International Nuclear Information System (INIS)

    Zhang, Hao-Xuan; Zhang, Xiu-Ping; Xiao, Gui-Yong; Hou, Yong; Cheng, Lei; Si, Meng; Wang, Shuai-Shuai; Li, Yu-Hua; Nie, Lin

    2016-01-01

    Avascular necrosis of the femoral head (ANFH) is difficult to treat due to high pressure and hypoxia, and reduced levels of growth factors such as bone morphogenetic protein (BMP), and vascular endothelial growth factor (VEGF). We generated a novel calcium phosphate (CPC) composite scaffold, which contains BMP-VEGF-loaded poly-lactic-co-glycolic acid (PLGA) microspheres (BMP-VEGF-PLGA-CPC). The BMP-VEGF-loaded microspheres have an encapsulation efficiency of 89.15% for BMP, and 78.55% for VEGF. The BMP-VEGF-PLGA-CPC scaffold also demonstrated a porosity of 62% with interconnected porous structures, and pore sizes of 219 μm and compressive strength of 6.60 MPa. Additionally, bone marrow mesenchymal stem cells (BMSCs) were seeded on scaffolds in vitro. Further characterization showed that the BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. Using a rabbit model of ANFH, BMP-VEGF-PLGA-CPC scaffolds were implanted into the bone tunnels of core decompression in the femoral head for 6 and 12 weeks. Radiographic and histological analysis demonstrated that the BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. These results indicate that the BMP-VEGF-PLGA-CPC scaffold may improve the therapeutic effect of core decompression surgery and be used as a treatment for ANFH. - Highlights: • BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. • BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. • BMP-VEGF-PLGA-CPC scaffolds provided a new approach for the treatment of avascular necrosis of the femoral head (ANFH).

  15. Ammonolysis-induced solvent removal: a facile approach for solidifying emulsion droplets into PLGA microspheres.

    Science.gov (United States)

    Kim, Jayoung; Hong, Dasom; Chung, Younglim; Sah, Hongkee

    2007-12-01

    An ammonolysis-based microencapsulation technique useful for the preparation of biodegradable microspheres was described in this study. A dispersed phase consisting of poly- d, l-lactide- co-glycolide, progesterone, and methyl chloroacetate was emulsified in an aqueous phase. Upon addition of ammonia solution, the emulsion droplets were quickly transformed into poly- d, l-lactide- co-glycolide microspheres laden with progesterone. Rapid solvent removal was accompanied by ammonolysis. The chemical reaction converted water-immiscible methyl chloroacetate to water-miscible chloroacetamide and methanol. Chloroacetamide formation was proved by (1)H NMR and ESI-MS studies. Thermogravimetric analysis showed that the microspheres contained only small amounts of residual methyl chloroacetate. Incorporation efficiencies of progesterone ranged from 64.3 +/- 1.1 to 72.8 +/- 0.3%, depending upon microsphere formulations. X-ray powder diffractometry analysis substantiated that no polymorphic transition of progesterone occurred during microencapsulation. To evaluate the feasibility of this new method against the commonly used microencapsulation method, microspheres were also prepared by a typical dichloromethane-based solvent evaporation process. The important attributes of microspheres prepared from both methods were characterized for comparison. The new ammonolysis-based microencapsulation process showed interesting features distinct from those of the solvent evaporation process. The microencapsulation process reported in this study might be applicable in loading pharmaceuticals into various polymeric microspheres.

  16. Sustained release donepezil loaded PLGA microspheres for injection: Preparation, in vitro and in vivo study

    DEFF Research Database (Denmark)

    Guo, Wenjia; Quan, Peng; Fang, Liang

    2015-01-01

    -solvent evaporation method. The optimized formulation which avoided the crushing of microspheres during the preparation process was characterized in terms of particle size, morphology, drug loading and EE, physical state of DP in the matrix and in vitro and in vivo release behavior. DP microspheres were prepared...... release mechanism. After single-dose administration of DP microspheres via subcutaneous injection in rats, the plasma concentration of DP reached peak concentration at 0.50 d, and then declined gradually, but was still detectable at 15 d. A good correlation between in vitro and in vivo data was obtained...

  17. Setting accelerated dissolution test for PLGA microspheres containing peptide, investigation of critical parameters affecting drug release rate and mechanism.

    Science.gov (United States)

    Tomic, I; Vidis-Millward, A; Mueller-Zsigmondy, M; Cardot, J-M

    2016-05-30

    The objective of this study was development of accelerated in vitro release method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug release rate and mechanism. Accelerated release conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while release rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, release rate showed three-fold deceleration without significant change in release mechanism. Effect of medium composition on drug release was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug release rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide release. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the release process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for accelerated in vitro dissolution testing for a given formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Doxycycline delivery from PLGA microspheres prepared by a modified solvent removal method.

    Science.gov (United States)

    Patel, Roshni S; Cho, Daniel Y; Tian, Cheng; Chang, Amy; Estrellas, Kenneth M; Lavin, Danya; Furtado, Stacia; Mathiowitz, Edith

    2012-01-01

    We report on the development of a modified solvent removal method for the encapsulation of hydrophilic drugs within poly(lactic-co-glycolic acid) (PLGA). Using a water/oil/oil double emulsion, hydrophilic doxycycline was encapsulated within PLGA spheres with particle diameters ranging from approximately 600 nm to 19 µm. Encapsulation efficiencies of up to 74% were achieved for theoretical loadings from 1% to 10% (w/w), with biphasic release over 85 days with nearly complete release at the end of this time course. About 1% salt was added to the formulations to examine its effects on doxycycline release; salt modulated release only by increasing the magnitude of initial release without altering kinetics. Fourier transform infrared spectroscopy indicated no characteristic differences between doxycycline-loaded and control spheres. Differential scanning calorimetry and X-ray diffraction suggest that there may be a molecular dispersion of the doxycycline within the spheres and the doxycycline may be in an amorphous state, which could explain the slow, prolonged release of the drug.

  19. Porous PLGA microspheres tailored for dual delivery of biomolecules via layer-by-layer assembly.

    Science.gov (United States)

    Go, Dewi P; Palmer, Jason A; Mitchell, Geraldine M; Gras, Sally L; O'Connor, Andrea J

    2015-05-01

    Tissue engineering is a complex and dynamic process that requires varied biomolecular cues to promote optimal tissue growth. Consequently, the development of delivery systems capable of sequestering more than one biomolecule with controllable release profiles is a key step in the advancement of this field. This study develops multilayered polyelectrolyte films incorporating alpha-melanocyte stimulating hormone (α-MSH), an anti-inflammatory molecule, and basic fibroblast growth factor (bFGF). The layers were successfully formed on macroporous poly lactic-co-glycolic acid microspheres produced using a combined inkjet and thermally induced phase separation technique. Release profiles could be varied by altering layer properties including the number of layers and concentrations of layering molecules. α-MSH and bFGF were released in a sustained manner and the bioactivity of α-MSH was shown to be preserved using an activated macrophage cell assay in vitro. The system performance was also tested in vivo subcutaneously in rats. The multilayered microspheres reduced the inflammatory response induced by a carrageenan stimulus 6 weeks after implantation compared to the non-layered microspheres without the anti-inflammatory and growth factors, demonstrating the potential of such multilayered constructs for the controlled delivery of bioactive molecules. © 2014 Wiley Periodicals, Inc.

  20. Physicochemical and mechanical properties of freeze cast hydroxyapatite-gelatin scaffolds with dexamethasone loaded PLGA microspheres for hard tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Ghorbani, Farnaz, E-mail: Farnaz_ghorbani.1991@yahoo.com [Department of Biomedical Engineering, Tehran Science and Research Branch, Islamic Azad University, P. O. Box: 4515/775, Tehran (Iran, Islamic Republic of); Nojehdehian, Hanieh, E-mail: hanieh.nojehdehyan@gmail.com [Department of Dental Materials, School of Dentistry, Shahid Beheshti University of Medical Sciences, P.O. Box: 1983963113, Tehran (Iran, Islamic Republic of); Zamanian, Ali, E-mail: a-zamanian@merc.ac.ir [Biomaterials Research Group, Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, P.O. Box: 14155-4777, Tehran (Iran, Islamic Republic of)

    2016-12-01

    Hydroxyapatite (HA)-gelatin scaffolds incorporated with dexamethasone-loaded polylactic-co-glycolic acid (PLGA) microspheres were synthesized by freeze casting technique. Scanning electron microscopy (SEM) micrographs demonstrated a unidirectional microstructure and a decrease in the pore size as a function of temperature gradient. Higher amounts of HA resulted in a decrease in the pore size. According to the results, at lower cooling rates, the formation of a lamellar structure decreased the mechanical strength, but at the same time, enhanced the swelling ratio, biodegradation rate and drug release level. On the other hand, higher weight ratios of HA increased the compressive strength, and reduced the swelling ratio, biodegradation rate and drug release level. The results obtained by furrier transform infrared spectroscopy (FTIR) and bioactivity analysis illustrated that the interactions of the materials support the apatite formation in the simulated body fluid (SBF) solution. Based on the obtained results, the synthesized composite scaffolds have the necessary mechanical and physicochemical features to support the regeneration of defects and to maintain their stability during the neo-tissue formation. - Highlights: • Freeze casting technique created unidirectional lamellar type microstructure. • Unidirectional microstructure of samples improved mechanical behavior, absorption, biodegradation rate and release behavior. • Hydroxyapatite-gelatin scaffolds demonstrated bioactive behavior and support new apatite layer formation. • Controlled release rate provided by dexamethasone loaded PLGA microspheres.

  1. Modified composite microspheres of hydroxyapatite and poly(lactide-co-glycolide) as an injectable scaffold

    International Nuclear Information System (INIS)

    Hu, Xixue; Shen, Hong; Yang, Fei; Liang, Xinjie; Wang, Shenguo; Wu, Decheng

    2014-01-01

    The compound of hydroxyapatite-poly(lactide-co-glycolide) (HA-PLGA) was prepared by ionic bond between HA and PLGA. HA-PLGA was more stable than the simple physical blend of hydroxyapatite and poly(lactide-co-glycolide) (HA/PLGA). The surface of HA-PLGA microsphere fabricated by an emulsion–solvent evaporation method was rougher than that of HA/PLGA microspheres. Moreover, surface HA content of HA-PLGA microspheres was more than that of HA/PLGA microspheres. In vitro mouse OCT-1 osteoblast-like cell culture results showed that the HA-PLGA microspheres clearly promoted osteoblast attachment, proliferation and alkaline phosphatase activity. It was considered that surface rich HA component and rough surface of HA-PLGA microsphere enhanced cell growth and differentiation. The good cell affinity of the HA-PLGA microspheres indicated that they could be used as an injectable scaffold for bone tissue engineering.

  2. Modified composite microspheres of hydroxyapatite and poly(lactide-co-glycolide) as an injectable scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xixue [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190 (China); Shen, Hong, E-mail: shenhong516@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Yang, Fei [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Liang, Xinjie [CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190 (China); Wang, Shenguo, E-mail: wangsg@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Decheng, E-mail: dcwu@iccas.ac.cn [BNLMS, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-02-15

    The compound of hydroxyapatite-poly(lactide-co-glycolide) (HA-PLGA) was prepared by ionic bond between HA and PLGA. HA-PLGA was more stable than the simple physical blend of hydroxyapatite and poly(lactide-co-glycolide) (HA/PLGA). The surface of HA-PLGA microsphere fabricated by an emulsion–solvent evaporation method was rougher than that of HA/PLGA microspheres. Moreover, surface HA content of HA-PLGA microspheres was more than that of HA/PLGA microspheres. In vitro mouse OCT-1 osteoblast-like cell culture results showed that the HA-PLGA microspheres clearly promoted osteoblast attachment, proliferation and alkaline phosphatase activity. It was considered that surface rich HA component and rough surface of HA-PLGA microsphere enhanced cell growth and differentiation. The good cell affinity of the HA-PLGA microspheres indicated that they could be used as an injectable scaffold for bone tissue engineering.

  3. Usnic acid-loaded biocompatible magnetic PLGA-PVA microsphere thin films fabricated by MAPLE with increased resistance to staphylococcal colonization

    International Nuclear Information System (INIS)

    Grumezescu, V; Grumezescu, A M; Ficai, A; Vasile, B S; Holban, A M; Lazar, V; Chifiriuc, C M; Socol, G; Truscă, R; Bleotu, C; Mogosanu, G D

    2014-01-01

    Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering. (paper)

  4. Usnic acid-loaded biocompatible magnetic PLGA-PVA microsphere thin films fabricated by MAPLE with increased resistance to staphylococcal colonization.

    Science.gov (United States)

    Grumezescu, V; Holban, A M; Grumezescu, A M; Socol, G; Ficai, A; Vasile, B S; Truscă, R; Bleotu, C; Lazar, V; Chifiriuc, C M; Mogosanu, G D

    2014-09-01

    Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering.

  5. Usnic acid-loaded biocompatible magnetic PLGA-PVA microsphere thin films fabricated by MAPLE with increased resistance to staphylococcal colonization

    Energy Technology Data Exchange (ETDEWEB)

    Grumezescu, V; Grumezescu, A M; Ficai, A; Vasile, B S [Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, Polizu Street no 1-7, 011061 Bucharest (Romania); Holban, A M; Lazar, V; Chifiriuc, C M [Microbiology Immunology Department, Faculty of Biology, University of Bucharest, Aleea Portocalelor 1-3, Sector 5, 77206-Bucharest (Romania); Socol, G [Lasers Department, Plasma and Radiation Physics, National Institute for Lasers, PO Box MG-36, Bucharest-Magurele (Romania); Truscă, R [Metav SA - CD SA, 31 Rosetti Str., 020015 Bucharest (Romania); Bleotu, C [Stefan S Nicolau Institute of Virology, Bucharest (Romania); Mogosanu, G D, E-mail: grumezescu@yahoo.com [Department of Pharmacognosy and Phytotherapy, Faculty of Pharmacy, University of Medicine and Pharmacy of Craiova, 2 PetruRareş Street, 200349 Craiova (Romania)

    2014-09-01

    Due to their persistence and resistance to the current therapeutic approaches, Staphylococcus aureus biofilm-associated infections represent a major cause of morbidity and mortality in the hospital environment. Since (+)-usnic acid (UA), a secondary lichen metabolite, possesses antimicrobial activity against Gram-positive cocci, including S. aureus, the aim of this study was to load magnetic polylactic-co-glycolic acid-polyvinyl alcohol (PLGA-PVA) microspheres with UA, then to obtain thin coatings using matrix-assisted pulsed laser evaporation and to quantitatively assess the capacity of the bio-nano-active modified surface to control biofilm formation by S. aureus, using a culture-based assay. The UA-loaded microspheres inhibited both the initial attachment of S. aureus to the coated surfaces, as well as the development of mature biofilms. In vitro bioevalution tests performed on the fabricated thin films revealed great biocompatibility, which may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to S. aureus colonization and as scaffolds for stem cell cultivation and tissue engineering. (paper)

  6. Protective efficacy of cationic-PLGA microspheres loaded with DNA vaccine encoding the sip gene of Streptococcus agalactiae in tilapia.

    Science.gov (United States)

    Ma, Yan-Ping; Ke, Hao; Liang, Zhi-Ling; Ma, Jiang-Yao; Hao, Le; Liu, Zhen-Xing

    2017-07-01

    Streptococcus agalactiae (S. agalactiae) is an important fish pathogen, which has received more attention in the past decade due to the increasing economic losses in the tilapia industry worldwide. As existing effective vaccines of S. agalactiae in fish have obvious disadvantage, to select immunoprotective antigens and package materials would undoubtedly contribute to the development of novel oral vaccines. In the present study, surface immunogenic protein (sip) was selected from the S. agalactiae serovar I a genomes as immunogenic protein in DNA vaccine form with cationic chitosan and biodegradable and biocompatible PLGA. The pcSip plasmid in cationic-PLGA was successfully expressed in tissues of immunized tilapia and the immunogenicity was assessed in tilapia challenge model. A significant increase was observed in the cytokine levels of IL-1β, TNF-α, CC1, CC2 in spleen and kidney tissues. Furthermore, immunized tilapia conferred different levels of protection against challenge with a lethal dose of highly virulent serovar I a S. agalactiae. Our results indicated that the pcSip plasmid in cationic-PLGA induced high level of antibodies and protection against S. agalactiae infection, could be effective oral DNA vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Rifapentine-linezolid-loaded PLGA microspheres for interventional therapy of cavitary pulmonary tuberculosis: preparation and in vitro characterization.

    Science.gov (United States)

    Huang, Jieyun; Chen, Zhi; Li, Ying; Li, Li; Zhang, Guangyu

    2017-01-01

    In this study, we aimed to design controlled-release microspheres for the treatment of cavitary pulmonary tuberculosis (TB) for solving the issues of poor drug delivery and short duration maintained at effective drug concentration during bronchoscopic interventional therapy. We fabricated rifapentine-linezolid-loaded poly(lactic acid-co-glycolic acid) microspheres (RLPMs) using the oil-in-water emulsion solvent evaporation method and assessed their in vitro release as well as the bronchial mucosal retention characteristics. The microspheres are spherical in shape with a circular concave on the surface. The particle size of RLPMs was 27.38±1.28 μm. The drug loading of rifapentine and linezolid was 18.51±0.26 and 8.42%±0.24%, respectively, while the encapsulation efficiencies were 55.53±0.78 and 16.87%±0.47%, respectively (n=3). During the burst release phase of the in vitro release test, 21.37%±0.68% rifapentine was released in 3 days and 43.56%±2.54% linezolid was released in 1 day. Then, both the drugs entered the sustained release phase. Finally, the cumulative percentage release of rifapentine and linezolid in 14 days was 27.61±1.52 and 51.01%±3.31%, respectively (n=3). Bronchoscopic observation revealed that the controlled-release microspheres could slowly release the drugs and retain them on the surface of bronchial mucosa of canines for 20 days. These results indicated that the fabricated microspheres exhibited a significant sustained release effect and could effectively retain the drugs on the surface of bronchial mucosa. Therefore, this study provides a theoretical and practical foundation for the development of fabricated microspheres loaded with multiple anti-TB drugs in the bronchoscopic interventional therapy of cavity pulmonary TB.

  8. Rifapentine-linezolid-loaded PLGA microspheres for interventional therapy of cavitary pulmonary tuberculosis: preparation and in vitro characterization

    Directory of Open Access Journals (Sweden)

    Huang J

    2017-03-01

    Full Text Available Jieyun Huang,1,* Zhi Chen,2,* Ying Li,3 Li Li,2 Guangyu Zhang2 1The Second Clinical Medical College, Shanxi Medical University, Taiyuan, People’s Republic of China; 2Institute for Tuberculosis Research, The 309th Hospital of Chinese PLA, Beijing, People’s Republic of China; 3Department of Drug Delivery Research Center, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: In this study, we aimed to design controlled-release microspheres for the treatment of cavitary pulmonary tuberculosis (TB for solving the issues of poor drug delivery and short duration maintained at effective drug concentration during bronchoscopic interventional therapy. We fabricated rifapentine-linezolid-loaded poly(lactic acid-co-glycolic acid microspheres (RLPMs using the oil-in-water emulsion solvent evaporation method and assessed their in vitro release as well as the bronchial mucosal retention characteristics. The microspheres are spherical in shape with a circular concave on the surface. The particle size of RLPMs was 27.38±1.28 µm. The drug loading of rifapentine and linezolid was 18.51±0.26 and 8.42%±0.24%, respectively, while the encapsulation efficiencies were 55.53±0.78 and 16.87%±0.47%, respectively (n=3. During the burst release phase of the in vitro release test, 21.37%±0.68% rifapentine was released in 3 days and 43.56%±2.54% linezolid was released in 1 day. Then, both the drugs entered the sustained release phase. Finally, the cumulative percentage release of rifapentine and linezolid in 14 days was 27.61±1.52 and 51.01%±3.31%, respectively (n=3. Bronchoscopic observation revealed that the controlled-release microspheres could slowly release the drugs and retain them on the surface of bronchial mucosa of canines for 20 days. These results indicated that the fabricated microspheres exhibited

  9. PLGA-PEG-PLGA microspheres as a delivery vehicle for antisense oligonucleotides to CTGF: Implications on post-surgical peritoneal adhesion prevention

    Science.gov (United States)

    Azeke, John Imuetinyan-Jesu, Jr.

    , while both cytokines are over-expressed within the first day following injury, CTGF protein levels could not be correlated with observed adhesion development. In addition, we synthesized linear triblock copolymers of polyethylene glycol (PEG) and poly(D,L-lactide-co-glycolide) (PLGA), two of the most widely studied biodegradable polymers in use today. Bulk gels and microparticles of the copolymers were then evaluated for gelling behavior, temperature stability, and drug loading and release kinetics in order assess their suitability as potential carriers of antisense therapeutics. A novel approach to affecting the antisense oligonucleotide release kinetics by varying the relative concentrations of co-encapsulated cationic lipid transfection agents was also presented.

  10. Physicochemical and mechanical properties of freeze cast hydroxyapatite-gelatin scaffolds with dexamethasone loaded PLGA microspheres for hard tissue engineering applications.

    Science.gov (United States)

    Ghorbani, Farnaz; Nojehdehian, Hanieh; Zamanian, Ali

    2016-12-01

    Hydroxyapatite (HA)-gelatin scaffolds incorporated with dexamethasone-loaded polylactic-co-glycolic acid (PLGA) microspheres were synthesized by freeze casting technique. Scanning electron microscopy (SEM) micrographs demonstrated a unidirectional microstructure and a decrease in the pore size as a function of temperature gradient. Higher amounts of HA resulted in a decrease in the pore size. According to the results, at lower cooling rates, the formation of a lamellar structure decreased the mechanical strength, but at the same time, enhanced the swelling ratio, biodegradation rate and drug release level. On the other hand, higher weight ratios of HA increased the compressive strength, and reduced the swelling ratio, biodegradation rate and drug release level. The results obtained by furrier transform infrared spectroscopy (FTIR) and bioactivity analysis illustrated that the interactions of the materials support the apatite formation in the simulated body fluid (SBF) solution. Based on the obtained results, the synthesized composite scaffolds have the necessary mechanical and physicochemical features to support the regeneration of defects and to maintain their stability during the neo-tissue formation. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Synthesis and characterization of magnesium gluconate contained poly(lactic-co-glycolic acid)/chitosan microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Shekh M. [Department of Chemical, Biological and Bioengineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Mahoney, Christopher [Department of Bioengineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA 15250 (United States); Sankar, Jagannathan [NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Department of Mechanical Engineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); Marra, Kacey G. [NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States); Department of Bioengineering, University of Pittsburgh, 4200 Fifth Avenue, Pittsburgh, PA 15250 (United States); Department of Plastic Surgery, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15250 (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, 450 Technology Drive, Pittsburgh, PA 15250 (United States); Bhattarai, Narayan, E-mail: nbhattar@ncat.edu [Department of Chemical, Biological and Bioengineering, North Carolina A& T State University, 1601 East Market Street, Greensboro, NC 27411 (United States); NSF Engineering Research Center for Revolutionizing Metallic Biomaterials, North Carolina A& T State University, Greensboro, NC 27411 (United States)

    2016-01-15

    Graphical abstract: - Highlights: • Magnesium gluconate contained PLGA/chitosan microspheres were fabricated. • In vitro release of magnesium ions was performed using Xylidyl Blue assay. • Chitosan coated PLGA can significantly control the release of magnesium ions. • Cellular compatibility was tested using adipose-derived stem cells and PC12 cells. • The cells encounter acceptably low levels of damage in contact with microspheres. - Abstract: The goal of this study was to fabricate and investigate the chitosan coated poly(lactic-co-glycolic acid) (PLGA) microspheres for the development of controlled release magnesium delivery system. PLGA based microspheres are ideal vehicles for many controlled release drug delivery applications. Chitosan is a naturally occurring biodegradable and biocompatible polysaccharide, which can coat the surface of PLGA to alter the release of drugs. Magnesium gluconate (MgG) was encapsulated in the PLGA and PLGA/chitosan microspheres by utilizing the double emulsion solvent evaporation technique for controlled release study. The microspheres were tested with respect to several physicochemical and biological properties, including morphology, chemical structure, chitosan adsorption efficiency, magnesium encapsulation efficiency, in vitro release of magnesium ions, and cellular compatibility using both human adipose-derived stem cells (ASCs) and PC12 cells. Chitosan coated PLGA microspheres can significantly control the release of magnesium ions compared to uncoated PLGA microspheres. Both coated and uncoated microspheres showed good cellular compatibility.

  12. Caffeic Acid-PLGA Conjugate to Design Protein Drug Delivery Systems Stable to Irradiation

    Directory of Open Access Journals (Sweden)

    Francesca Selmin

    2015-01-01

    Full Text Available This work reports the feasibility of caffeic acid grafted PLGA (g-CA-PLGA to design biodegradable sterile microspheres for the delivery of proteins. Ovalbumin (OVA was selected as model compound because of its sensitiveness of γ-radiation. The adopted grafting procedure allowed us to obtain a material with good free radical scavenging properties, without a significant modification of Mw and Tg of the starting PLGA (Mw PLGA = 26.3 ± 1.3 kDa vs. Mw g-CA-PLGA = 22.8 ± 0.7 kDa; Tg PLGA = 47.7 ± 0.8 °C vs. Tg g-CA-PLGA = 47.4 ± 0.2 °C. By using a W1/O/W2 technique, g-CA-PLGA improved the encapsulation efficiency (EE, suggesting that the presence of caffeic residues improved the compatibility between components (EEPLGA = 35.0% ± 0.7% vs. EEg-CA-PLGA = 95.6% ± 2.7%. Microspheres particle size distribution ranged from 15 to 50 µm. The zeta-potential values of placebo and loaded microspheres were −25 mV and −15 mV, respectively. The irradiation of g-CA-PLGA at the dose of 25 kGy caused a less than 1% variation of Mw and the degradation patterns of the non-irradiated and irradiated microspheres were superimposable. The OVA content in g-CA-PLGA microspheres decreased to a lower extent with respect to PLGA microspheres. These results suggest that g-CA-PLGA is a promising biodegradable material to microencapsulate biological drugs.

  13. Influence of different formulations and process parameters during the preparation of drug-loaded PLGA microspheres evaluated by multivariate data analysis

    Directory of Open Access Journals (Sweden)

    Vysloužil Jakub

    2014-12-01

    Full Text Available The main objective of this study was to evaluate the influence of the formulation and process parameters on PLGA microparticles containing a practically insoluble model drug (ibuprofen prepared by the o/w solvent evaporation method. Multivariate data analysis was used. The effects of altered stirring speed of a mechanical stirrer (600, 1000 rpm, emulsifier concentrations (PVA concentration 0.1 %, 1 % and solvent selection (dichloromethane, ethyl acetate on microparticle characteristics (encapsulation efficiency, drug loading, burst effect were observed. It was found that with increased stirring speed, the PVA concentration or the use of ethyl acetate had a significantly negative effect on encapsulation efficiency. In addition, ethyl acetate had an adverse effect on the burst effect, while increased stirring speed had the opposite effect. Drug load was not affected by any particular variable, but rather by the interactions of evaluated variables.

  14. Size effect of PLGA spheres on drug loading efficiency and release profiles

    NARCIS (Netherlands)

    Dawes, G.J.S.; Fratila-Apachitei, L.E.; Mulia, K.; Apachitei, I.; Witkamp, G.J.; Duszczyk, J.

    2009-01-01

    Drug delivery systems (DDS) based on poly (lactide-co-glycolide) (PLGA) microspheres and nanospheres have been separately studied in previous works as a means of delivering bioactive compounds over an extended period of time. In the present study, two DDS having different sizes of the PLGA spheres

  15. Polymer based microspheres of aceclofenac as sustained release parenterals for prolonged anti-inflammatory effect

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet; Sharma, Sumit; Sinha, VR, E-mail: sinha_vr@rediffmail.com

    2017-03-01

    Poly(lactic-co-glycolic acid) (PLGA) (75:25) and polycaprolactone (PCL) microspheres were fabricated for prolonged release of aceclofenac by parenteral administration. Microspheres encapsulating aceclofenac were designed to release the drug at controlled rate for around one month. Biodegradable microspheres were prepared by solvent emulsification evaporation method in different polymer:drug ratios (1:1, 2:1 and 3:1). After drug loading, PLGA and PCL microspheres showed a controlled size distribution with an average size of 11.75 μm and 3.81 μm respectively and entrapment efficiency in the range of 90 ± 0.72% to 91.06 ± 4.01% with PLGA and 83.01 ± 2.13% to 90.4 ± 2.11% with PCL. Scanning electron microscopy has confirmed good spherical structures of microspheres. The percent yield of biodegradable polymeric microspheres ranged between 30.95 ± 10.14% to 92.84 ± 3.15% and 47.33 ± 4.72% to 80 ± 3.60% for PLGA and PCL microspheres respectively. PLGA microspheres followed Higuchi release pattern while Korsmeyer-Peppas explained the release pattern of PCL microspheres. Stability studies of microspheres were also carried out by storing the preparations at 2-8 °C for 30, 60 and 90 days and evaluating them for entrapment efficiency, residual drug content and polymer drug compatability. In-vivo studies showed significant anti-inflammatory activity of microspheres upto 48 hours using the carrageenan induced rat paw oedema model. - Highlights: • PLGA and PCL polymeric microspheres for parenteral prolonged drug delivery system were formulated. • Polymeric microspheres were characterized physically and drug excipient incompatability. • Three months accelerated stability studies were carried for drug loaded polymeric microspheres. • Pharmacodynamic studies prove the rationality of sustained therapeutic effect of designed drug delivery system.

  16. MICROSPHERE SIZE INFLUENCES THE FOREIGN BODY REACTION

    NARCIS (Netherlands)

    Zandstra, J.; Hiemstra, C.; Petersen, A. H.; Zuidema, J.; van Beuge, M. M.; Rodriguez, S.; Lathuile, A. A. R.; Veldhuis, G. J.; Steendam, R.; Bank, R. A.; Popa, E. R.

    2014-01-01

    Biodegradable poly-(DL-lactide-co-glycolide) (PLGA) microspheres (MSP) are attractive candidate vehicles for site-specific or systemic sustained release of therapeutic compounds. This release may be altered by the host's foreign body reaction (FBR), which is dependent on the characteristics of the

  17. Biological Properties of Low-Toxic PLGA and PLGA/PHB Fibrous Nanocomposite Scaffolds for Osseous Tissue Regeneration. Evaluation of Potential Bioactivity

    Directory of Open Access Journals (Sweden)

    Boguslawa Żywicka

    2017-10-01

    Full Text Available Abstracts: The aim of the study was to evaluate the biocompatibility and bioactivity of two new prototype implants for bone tissue regeneration made from biodegradable fibrous materials. The first is a newly developed poly(l-lactide-co-glycolide, (PLGA, and the second is a blend of PLGA with synthetic poly([R,S]-3-hydroxybutyrate (PLGA/PHB. The implant prototypes comprise PLGA or PLGA/PHB nonwoven fabrics with designed pore structures to create the best conditions for cell proliferation. The bioactivity of the proposed implants was enhanced by introducing a hydroxyapatite material and a biologically active agent, namely, growth factor IGF1, encapsulated in calcium alginate microspheres. To assess the biocompatibility and bioactivity, allergenic tests and an assessment of the local reaction of bone tissue after implantation were performed. Comparative studies of local tissue response after implantation into trochanters for a period of 12 months were performed on New Zealand rabbits. Based on the results of the in vivo evaluation of the allergenic effects and the local tissue reaction 12 months after implantation, it was concluded that the two implant prototypes, PLGA + IGF1 and PLGA/PHB + IGF1, were characterized by high biocompatibility with the soft and bone tissues of the tested animals.

  18. Combination therapy of surgical tumor resection with implantation of a hydrogel containing camptothecin-loaded poly(lactic-co-glycolic acid) microspheres in a C6 rat glioma model.

    Science.gov (United States)

    Ozeki, Tetsuya; Kaneko, Daiki; Hashizawa, Kosuke; Imai, Yoshihiro; Tagami, Tatsuaki; Okada, Hiroaki

    2012-01-01

    We have developed a drug-loaded poly(lactic-co-glycolic acid) (PLGA) microsphere-containing thermoreversible gelation polymer (TGP) (drug/PLGA/TGP) formulation as a novel device for implantation after surgical glioma resection. TGP is a thermosensitive polymer that is a gel at body temperature and a sol at room temperature. When a drug/PLGA/TGP formulation is injected into a target site, PLGA microspheres in TGP gel localize at the injection site and do not diffuse across the entire brain tissue, and thus, sustained drug release from the PLGA microspheres at the target site is expected. Using in vivo imaging, we confirmed that the implantation of indocyanine green (ICG)/PLGA/TGP formulation exhibited a stronger localization of ICG at the injection site 28 d after injection compared with that of ICG/PLGA formulation. The therapeutic effect (mean survival) was evaluated in a C6 rat glioma model. Surgical tumor resection alone showed almost no effect on survival (controls, 18 d; surgical resection; 18.5 d). Survival was prolonged after the treatment with a camptothecin (CPT; 10 µg)/PLGA/TGP formulation (24 d). The combination treatment of surgical tumor resection and CPT/PLGA/TGP showed almost the same therapeutic effect (24 d) compared with CPT/PLGA/TGP alone, while the combination treatment produced long term survivors (>60 d). Therefore, the CPT/PLGA/TGP formulation can be an effective candidate for localized and sustained long-term glioma therapy.

  19. Subcritical CO{sub 2} sintering of microspheres of different polymeric materials to fabricate scaffolds for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Bhamidipati, Manjari; Sridharan, BanuPriya [Bioengineering Graduate Program, University of Kansas, Lawrence, KS (United States); Scurto, Aaron M. [Bioengineering Graduate Program, University of Kansas, Lawrence, KS (United States); Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, KS (United States); Detamore, Michael S., E-mail: detamore@ku.edu [Bioengineering Graduate Program, University of Kansas, Lawrence, KS (United States); Department of Chemical and Petroleum Engineering, University of Kansas, Lawrence, KS (United States)

    2013-12-01

    The aim of this study was to use CO{sub 2} at sub-critical pressures as a tool to sinter 3D, macroporous, microsphere-based scaffolds for bone and cartilage tissue engineering. Porous scaffolds composed of ∼ 200 μm microspheres of either poly(lactic-co-glycolic acid) (PLGA) or polycaprolactone (PCL) were prepared using dense phase CO{sub 2} sintering, which were seeded with rat bone marrow mesenchymal stromal cells (rBMSCs), and exposed to either osteogenic (PLGA, PCL) or chondrogenic (PLGA) conditions for 6 weeks. Under osteogenic conditions, the PLGA constructs produced over an order of magnitude more calcium than the PCL constructs, whereas the PCL constructs had far superior mechanical and structural integrity (125 times stiffer than PLGA constructs) at week 6, along with twice the cell content of the PLGA constructs. Chondrogenic cell performance was limited in PLGA constructs, perhaps as a result of the polymer degradation rate being too high. The current study represents the first long-term culture of CO{sub 2}-sintered microsphere-based scaffolds, and has established important thermodynamic differences in sintering between the selected formulations of PLGA and PCL, with the former requiring adjustment of pressure only, and the latter requiring the adjustment of both pressure and temperature. Based on more straightforward sintering conditions and more favorable cell performance, PLGA may be the material of choice for microspheres in a CO{sub 2} sintering application, although a different PLGA formulation with the encapsulation of growth factors, extracellular matrix-derived nanoparticles, and/or buffers in the microspheres may be advantageous for achieving a more superior cell performance than observed here. - Highlights: • The first long-term culture of CO{sub 2}-sintered microsphere-based scaffolds. • Established important thermodynamic differences between sintering PLGA and PCL. • PCL sintering with CO{sub 2} required manipulation of both

  20. Controlled drug release from a novel injectable biodegradable microsphere/scaffold composite based on poly(propylene fumarate).

    Science.gov (United States)

    Kempen, Diederik H R; Lu, Lichun; Kim, Choll; Zhu, Xun; Dhert, Wouter J A; Currier, Bradford L; Yaszemski, Michael J

    2006-04-01

    The ideal biomaterial for the repair of bone defects is expected to have good mechanical properties, be fabricated easily into a desired shape, support cell attachment, allow controlled release of bioactive factors to induce bone formation, and biodegrade into nontoxic products to permit natural bone formation and remodeling. The synthetic polymer poly(propylene fumarate) (PPF) holds great promise as such a biomaterial. In previous work we developed poly(DL-lactic-co-glycolic acid) (PLGA) and PPF microspheres for the controlled delivery of bioactive molecules. This study presents an approach to incorporate these microspheres into an injectable, porous PPF scaffold. Model drug Texas red dextran (TRD) was encapsulated into biodegradable PLGA and PPF microspheres at 2 microg/mg microsphere. Five porous composite formulations were fabricated via a gas foaming technique by combining the injectable PPF paste with the PLGA or PPF microspheres at 100 or 250 mg microsphere per composite formulation, or a control aqueous TRD solution (200 microg per composite). All scaffolds had an interconnected pore network with an average porosity of 64.8 +/- 3.6%. The presence of microspheres in the composite scaffolds was confirmed by scanning electron microscopy and confocal microscopy. The composite scaffolds exhibited a sustained release of the model drug for at least 28 days and had minimal burst release during the initial phase of release, as compared to drug release from microspheres alone. The compressive moduli of the scaffolds were between 2.4 and 26.2 MPa after fabrication, and between 14.9 and 62.8 MPa after 28 days in PBS. The scaffolds containing PPF microspheres exhibited a significantly higher initial compressive modulus than those containing PLGA microspheres. Increasing the amount of microspheres in the composites was found to significantly decrease the initial compressive modulus. The novel injectable PPF-based microsphere/scaffold composites developed in this study

  1. Porous poly (lactic-co-glycolide) microsphere sintered scaffolds for tissue repair applications

    International Nuclear Information System (INIS)

    Wang Yingjun; Shi Xuetao; Ren Li; Wang Chunming; Wang Dongan

    2009-01-01

    In this paper, a new route to preparing porous poly (lactic-co-glycolide) (PLGA) scaffolds for bone tissue repair applications was developed. Novel porous PLGA scaffolds were fabricated via microsphere sintered technique and gas forming technique. Ammonium bicarbonate was used to regulate porosity of these porous scaffolds. Porosity of the scaffolds, and cell attachment, viability and proliferation on the scaffolds were evaluated. The results indicated that PLGA porous scaffolds were with the porosity from around 30% to 95% by regulating ammonium bicarbonate content from 0 to 10%. We also found that PLGA porous microsphere scaffolds benefited cell attachment and viability. Taken together, the achieved porous scaffolds have controlled porosity and also support mesenchymal stem cell proliferation, which could serve as potential scaffolds for bone repair applications.

  2. Poly(lactide-co-glycolide) encapsulated hydroxyapatite microspheres for sustained release of doxycycline

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoyun [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Department of Pharmacy, Shandong Drug and Food Vocational College, Science and Technology Town, Hightech Industrial Development Zone, Weihai 264210 (China); Xu Hui; Zhao Yanqiu [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Wang Shaoning, E-mail: wsn-xh@126.com [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Abe, Hiroya; Naito, Makio [Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Liu Yanli [School of Pharmacy, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China); Wang Guoqing [School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, 103, Wenhua Road, Shenyang 110016 (China)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer PLGA encapsulated HAP-MSs were used for the sustained delivery of Doxycycline (Doxy, a broad spectrum tetracycline antibiotic). Black-Right-Pointing-Pointer Sustained Doxy release without obvious burst was observed. Black-Right-Pointing-Pointer Mechanism of the sustained Doxy release was illustrated. Black-Right-Pointing-Pointer Sustained Doxy release character in vivo was also obtained, the plasma Doxy levels were relatively lower and steady compared to that of the un-encapsulated HAP-MSs. - Abstract: The purpose of this study was to prepare a poly(lactide-co-glycolide) (PLGA) encapsulated hydroxyapatite microspheres (HAP-MSs) as injectable depot for sustained delivery of Doxycycline (Doxy). Doxy loaded HAP-MSs (Doxy-HAP-MSs) were encapsulated with PLGA by solid-in-oil-in-water (S/O/W) emulsion-solvent evaporation technique, the effects of the PLGA used (various intrinsic viscosity and LA/GA ratio) and ratio of PLGA/HAP-MSs on the formation of Doxy-HAP-MSs and in vitro release of Doxy were studied. The results showed that sustained drug release without obvious burst was obtained by using PLGA encapsulated HAP-MSs as the carrier, also the drug release rate could be tailored by changing the ratio of PLGA/HAP-MSs, or PLGA of various intrinsic viscosities or LA/GA ratio. Lower ratio of PLGA/HAP-MSs corresponded faster Doxy release, e.g. for the microspheres of PLGA/HAP-MSs ratio of 8 and 0.25, the in vitro Doxy release percents at the end of 7days were about 23% and 76%, respectively. Higher hydrophilicity (higher ratio of GA to LA) and lower molecular weight of PLGA corresponded to higher Doxy release rates. For in vivo release study, PLGA encapsulated HAP-MSs were subcutaneously injected to the back of mice, and the results showed good correlation between the in vivo and in vitro drug release. Meanwhile, the plasma Doxy levels after subcutaneous administration of PLGA encapsulated Doxy-HAP-MSs were relatively lower and steady

  3. Poly(lactide-co-glycolide) encapsulated hydroxyapatite microspheres for sustained release of doxycycline

    International Nuclear Information System (INIS)

    Wang Xiaoyun; Xu Hui; Zhao Yanqiu; Wang Shaoning; Abe, Hiroya; Naito, Makio; Liu Yanli; Wang Guoqing

    2012-01-01

    Highlights: ► PLGA encapsulated HAP-MSs were used for the sustained delivery of Doxycycline (Doxy, a broad spectrum tetracycline antibiotic). ► Sustained Doxy release without obvious burst was observed. ► Mechanism of the sustained Doxy release was illustrated. ► Sustained Doxy release character in vivo was also obtained, the plasma Doxy levels were relatively lower and steady compared to that of the un-encapsulated HAP-MSs. - Abstract: The purpose of this study was to prepare a poly(lactide-co-glycolide) (PLGA) encapsulated hydroxyapatite microspheres (HAP-MSs) as injectable depot for sustained delivery of Doxycycline (Doxy). Doxy loaded HAP-MSs (Doxy-HAP-MSs) were encapsulated with PLGA by solid-in-oil-in-water (S/O/W) emulsion-solvent evaporation technique, the effects of the PLGA used (various intrinsic viscosity and LA/GA ratio) and ratio of PLGA/HAP-MSs on the formation of Doxy-HAP-MSs and in vitro release of Doxy were studied. The results showed that sustained drug release without obvious burst was obtained by using PLGA encapsulated HAP-MSs as the carrier, also the drug release rate could be tailored by changing the ratio of PLGA/HAP-MSs, or PLGA of various intrinsic viscosities or LA/GA ratio. Lower ratio of PLGA/HAP-MSs corresponded faster Doxy release, e.g. for the microspheres of PLGA/HAP-MSs ratio of 8 and 0.25, the in vitro Doxy release percents at the end of 7days were about 23% and 76%, respectively. Higher hydrophilicity (higher ratio of GA to LA) and lower molecular weight of PLGA corresponded to higher Doxy release rates. For in vivo release study, PLGA encapsulated HAP-MSs were subcutaneously injected to the back of mice, and the results showed good correlation between the in vivo and in vitro drug release. Meanwhile, the plasma Doxy levels after subcutaneous administration of PLGA encapsulated Doxy-HAP-MSs were relatively lower and steady compared to that of the un-encapsulated microspheres. In conclusion, PLGA encapsulated HAP-MSs may

  4. Biodegradable polymeric microsphere-based drug delivery for inductive browning of fat

    Directory of Open Access Journals (Sweden)

    Chunhui eJiang

    2015-11-01

    Full Text Available Brown and beige adipocytes are potent therapeutic agents to increase energy expenditure and reduce risks of obesity and its affiliated metabolic symptoms. One strategy to increase beige adipocyte content is through inhibition of the evolutionarily conserved Notch signaling pathway. However, systemic delivery of Notch inhibitors is associated with off-target effects and multiple dosages of application further faces technical and translational challenges. Here, we report the development of a biodegradable polymeric microsphere-based drug delivery system for sustained, local release of a Notch inhibitor, DBZ. The microsphere-based delivery system was fabricated and optimized using an emulsion/solvent evaporation technique to encapsulate DBZ into poly(lactide-co-glycolide (PLGA, a commonly used biodegradable polymer for controlled drug release. Release studies revealed the ability of PLGA microspheres to release DBZ in a sustained manner. Co-culture of white adipocytes with and without DBZ-loaded PLGA microspheres demonstrated that the released DBZ retained its bioactivity, and effectively inhibited Notch and promoted browning of white adipocytes. Injection of these DBZ-loaded PLGA microspheres into mouse inguinal white adipose tissue (WAT depots resulted in browning in vivo. Our results provide the encouraging proof-of-principle evidence for the application of biodegradable polymers as a controlled release platform for delivery of browning factors, and pave the way for development of new translational therapeutic strategies for treatment of obesity.

  5. A dual-application poly (dl-lactic-co-glycolic) acid (PLGA)-chitosan composite scaffold for potential use in bone tissue engineering.

    Science.gov (United States)

    Boukari, Yamina; Qutachi, Omar; Scurr, David J; Morris, Andrew P; Doughty, Stephen W; Billa, Nashiru

    2017-11-01

    The development of patient-friendly alternatives to bone-graft procedures is the driving force for new frontiers in bone tissue engineering. Poly (dl-lactic-co-glycolic acid) (PLGA) and chitosan are well-studied and easy-to-process polymers from which scaffolds can be fabricated. In this study, a novel dual-application scaffold system was formulated from porous PLGA and protein-loaded PLGA/chitosan microspheres. Physicochemical and in vitro protein release attributes were established. The therapeutic relevance, cytocompatibility with primary human mesenchymal stem cells (hMSCs) and osteogenic properties were tested. There was a significant reduction in burst release from the composite PLGA/chitosan microspheres compared with PLGA alone. Scaffolds sintered from porous microspheres at 37 °C were significantly stronger than the PLGA control, with compressive strengths of 0.846 ± 0.272 MPa and 0.406 ± 0.265 MPa, respectively (p < 0.05). The formulation also sintered at 37 °C following injection through a needle, demonstrating its injectable potential. The scaffolds demonstrated cytocompatibility, with increased cell numbers observed over an 8-day study period. Von Kossa and immunostaining of the hMSC-scaffolds confirmed their osteogenic potential with the ability to sinter at 37 °C in situ.

  6. Design of a formulation for the preparation of 99m Tc-(V)-Dmsa and 186 Re-(V)-Dmsa

    International Nuclear Information System (INIS)

    Marquez L, M.B.

    1998-01-01

    Among the radiopharmaceuticals used for neoplasia, we can find the dimercaptosuccinic acid (Dmsa) labelled with 99m Tc and 186/188 Re. Initially, the 99m Tc-(III)-Dmsa was employed as a renal image agent. Nevertheless, when it is prepared into a basic solution, the 99m Tc-(V)-Dmsa complex is produced in high yield being cumulated by cells with a great metabolic activity. This property makes it a useful radiopharmaceutical for the detection of medullary thyroid carcinoma (MTC), soft-tissue tumors and other head and neck tumors. On the other hand, the renewed interest in β - emitting radionuclides, suggests that the 186 Re-(V)-Dmsa complex could be used as antineoplastic agent in therapy. However, the techniques reported for the preparation of these compounds lack of stability studies and they are still in process of investigation, compromising to continue on the development of the radiopharmaceuticals by introducing new possibilities for better products already known, obtaining in this way, the approximation to the ideal radiopharmaceutical. The objective of this work is to design a freeze dried kit formulation for the instant preparation of 99m Tc-(V)-Dmsa and 186 Re-(V)-Dmsa complexes useful in the diagnostic and therapy of soft-tissue tumors and other head and neck tumors. We obtained a freeze dried stable formulation for the preparation of 99m Tc-(V)-Dmsa kit with a radiochemical purity higher than 90 %, which fulfills with the quality control of radiopharmaceuticals. Furthermore, we developed analytical techniques for the determination of the different chemical compounds into the lyophilized kit. On the other hand, we obtained the optimum conditions for preparation of 186 Re-(V)-Dmsa complex in high radiochemical yields (>90%). (Author)

  7. Effect of gamma-irradiation on biodegradable microspheres loaded with rasagiline mesylate

    International Nuclear Information System (INIS)

    Fernandez, Marcos; Barcia, Emilia; Negro, Sofia

    2016-01-01

    In the present study, the influence of gamma-irradiation was evaluated on the physicochemical characteristics and in vitro release of rasagiline mesylate (RM), a selective MAO-B inhibitor used in Parkinson's disease, from poly(D,L-lactide-co-glycolide) (PLGA) microspheres. Microspheres were prepared using PLGA 50:50 by the solvent evaporation technique (O/W emulsion). Microspheres were sterilized by gamma-irradiation and their influence was assessed by scanning electron microscopy (SEM), laser light diffraction, differential scanning calorimetry (DSC), X-ray diffraction (XRD), gel permeation chromatography (GPC), encapsulation efficiency (EE) and in vitro drug release. Gamma-irradiation of RM-loaded microspheres did not affect EE, DSC and XRD patterns. After gamma-irradiation, changes on the surface were observed by SEM, but no significant difference in mean particle size was observed. GPC measurements showed a decrease in molecular weight of the polymer after five days of in vitro release. The similarity factor value between irradiated and non-irradiates microspheres was <50, indicating the non-similarity of the release profiles. The sterilization technique had an effect on the integrity of polymeric system, significantly affecting in vitro release of RM from PLGA microspheres. Therefore, from our results we conclude that gamma-irradiation is not a suitable sterilization procedure for this formulation

  8. A Biomimetic Approach to Active Self-Microencapsulation of Proteins in PLGA

    Science.gov (United States)

    Shah, Ronak B.; Schwendeman, Steven P.

    2014-01-01

    A biomimetic approach to organic solvent-free microencapsulation of proteins based on the self-healing capacity of poly (DL)-lactic-co-glycolic acid (PLGA) microspheres containing glycosaminoglycan-like biopolymers (BPs), was examined. To screen BPs, aqueous solutions of BP [high molecular weight dextran sulfate (HDS), low molecular weight dextran sulfate (LDS), chondroitin sulfate (CS), heparin (HP), hyaluronic acid (HA), chitosan (CH)] and model protein lysozyme (LYZ) were combined in different molar and mass ratios, at 37 °C and pH 7. The BP-PLGA microspheres (20–63 µm) were prepared by a double water-oil-water emulsion method with a range of BP content, and trehalose and MgCO3 to control microclimate pH and to create percolating pores for protein. Biomimetic active self-encapsulation (ASE) of proteins [LYZ, vascular endothelial growth factor165 (VEGF) and fibroblast growth factor (FgF-20)] was accomplished by incubating blank BP-PLGA microspheres in low concentration protein solutions at ~24 °C, for 48 h. Pore closure was induced at 42.5 °C under mild agitation for 42 h. Formulation parameters of BP-PLGA microspheres and loading conditions were studied to optimize protein loading and subsequent release. LDS and HP were found to bind >95% LYZ at BP:LYZ >0.125 w/w, whereas HDS and CS bound > 80% LYZ at BP:LYZ of 0.25–1 and 2% w/w of LYZ). Sulfated BP-PLGA microspheres were capable of loading LYZ (~2–7 % w/w), VEGF (~ 4% w/w), and FgF-20 (~2% w/w) with high efficiency. Protein loading was found to be dependent on the loading solution concentration, with higher protein loading obtained at higher loading solution concentration within the range investigated. Loading also increased with content of sulfated BP in microspheres. Release kinetics of proteins was evaluated in-vitro with complete release media replacement. Rate and extent of release were found to depend upon volume of release (with non-sink conditions observed 90 % of protein being enzymatically

  9. Data of evolutionary structure change: 1DMSA-1TMOA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1DMSA-1TMOA 1DMS 1TMO A A LANGTVMSGSHWGVFTATVENGRATAFTPWEKDPHPTPMLEGVLDSIYSPTRIKYPMVRREFLEKGVNADRSTRGNGDFVRVSWDQALDLVAA...index> 1DMS A 1DMS...VID> 1 1DMS A 1DMSA 2.436803102493286 2 1DMS... A 1DMSA QLNGT-VLREG

  10. Synchrotron radiation-based Fourier-transform infrared spectromicroscopy for characterization of the protein/peptide distribution in single microspheres

    Directory of Open Access Journals (Sweden)

    Manli Wang

    2015-05-01

    Full Text Available The present study establishes a visualization method for the measurement of the distribution and localization of protein/peptide constituents within a single poly-lactide-co-glycolide (PLGA microsphere using synchrotron radiation–based Fourier-transform infrared spectromicroscopy (SR-FTIR. The representative infrared wavenumbers specific for protein/peptide (Exenatide and excipient (PLGA were identified and chemical maps at the single microsphere level were generated by measuring and plotting the intensity of these specific bands. For quantitative analysis of the distribution within microspheres, Matlab software was used to transform the map file into a 3D matrix and the matrix values specific for the drug and excipient were extracted. Comparison of the normalized SR-FTIR maps of PLGA and Exenatide indicated that PLGA was uniformly distributed, while Exenatide was relatively non-uniformly distributed in the microspheres. In conclusion, SR-FTIR is a rapid, nondestructive and sensitive detection technology to provide the distribution of chemical constituents and functional groups in microparticles and microspheres.

  11. Comparative assessment of in vitro release kinetics of calcitonin polypeptide from biodegradable microspheres.

    Science.gov (United States)

    Prabhu, Sunil; Sullivan, Jennifer L; Betageri, Guru V

    2002-01-01

    The objective of our study was to compare the in vitro release kinetics of a sustained-release injectable microsphere formulation of the polypeptide drug, calcitonin (CT), to optimize the characteristics of drug release from poly-(lactide-co-glycolide) (PLGA) copolymer biodegradable microspheres. A modified solvent evaporation and double emulsion technique was used to prepare the microspheres. Release kinetic studies were carried out in silanized tubes and dialysis bags, whereby microspheres were suspended and incubated in phosphate buffered saline, sampled at fixed intervals, and analyzed for drug content using a modified Lowry protein assay procedure. An initial burst was observed whereby about 50% of the total dose of the drug was released from the microspheres within 24 hr and 75% within 3 days. This was followed by a period of slow release over a period of 3 weeks in which another 10-15% of drug was released. Drug release from the dialysis bags was more gradual, and 50% CT was released only after 4 days and 75% after 12 days of release. Scanning electron micrographs revealed spherical particles with channel-like structures and a porous surface after being suspended in an aqueous solution for 5 days. Differential scanning calorimetric studies revealed that CT was present as a mix of amorphous and crystalline forms within the microspheres. Overall, these studies demonstrated that sustained release of CT from PLGA microspheres over a 3-week period is feasible and that release of drug from dialysis bags was more predictable than from tubes.

  12. Microradiographic microsphere manipulator

    International Nuclear Information System (INIS)

    Singleton, R.M.

    1980-01-01

    A method and apparatus are provided for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated to relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres

  13. New PLGA-P188-PLGA matrix enhances TGF-β3 release from pharmacologically active microcarriers and promotes chondrogenesis of mesenchymal stem cells.

    Science.gov (United States)

    Morille, Marie; Van-Thanh, Tran; Garric, Xavier; Cayon, Jérôme; Coudane, Jean; Noël, Danièle; Venier-Julienne, Marie-Claire; Montero-Menei, Claudia N

    2013-08-28

    The use of injectable scaffolding materials for in vivo tissue regeneration has raised great interest in various clinical applications because it allows cell implantation through minimally invasive surgical procedures. In case of cartilage repair, a tissue engineered construct should provide a support for the cell and allow sustained in situ delivery of bioactive factors capable of inducing cell differentiation into chondrocytes. Pharmacologically active microcarriers (PAMs), made of biodegradable poly(d,l-lactide-co-glycolide acid) (PLGA), are a unique system, which combines these properties in an adaptable and simple microdevice. However, a limitation of such scaffold is low and incomplete protein release that occurs using the hydrophobic PLGA based microspheres. To circumvent this problem, we developed a novel formulation of polymeric PAMs containing a P188 poloxamer, which protects the protein from denaturation and may positively affect chondrogenesis. This poloxamer was added as a free additive for protein complexation and as a component of the scaffold covalently linked to PLGA. This procedure allows getting a more hydrophilic scaffold but also retaining the protective polymer inside the microcarriers during their degradation. The novel PLGA-P188-PLGA PAMs presenting a fibronectin-covered surface allowed enhanced MSC survival and proliferation. When engineered with TGFβ3, they allowed the sustained release of 70% of the incorporated TGF-β3 over time. Importantly, they exerted superior chondrogenic differentiation potential compared to previous FN-PAM-PLGA-TGF-β3, as shown by an increased expression of specific cartilage markers such as cartilage type II, aggrecan and COMP. Therefore, this microdevice represents an efficient easy-to-handle and injectable tool for cartilage repair. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

    International Nuclear Information System (INIS)

    Camacho, V.; Estorch, M.; Tembl, A.; Mena, E.; Flotats, A.; Hernandez, Ma.; Fraga, G.; Carrio, I.

    2002-01-01

    DMSA study is an established method for the assessment of renal sequelae after acute pyelonephritis related to febrile urinary tract infection (UTI). However, at the moment is not established if the DMSA study performed during the acute UTI has any prognostic value for outcome assessment. Objectives: to assess the usefulness of DMSA study performed during febrile UTI as predictor of patient outcome. Methods: One hundred-fifty-two children (74 boys) with mean age 20 months (range 1m-12 y) with first febrile UTI were studied by DMSA planar scintigraphy during the acute illness period (first 5 days). All patients had positive grown bacillus in urine (78% E. coli, 8% P. mirabilis), and all followed the same antibiotic treatment. After acute UTI all patients were explored by voiding cysto urethrography for diagnosis of vesicoureteral reflux (VUR). Fifty-seven patients who had an abnormal DMSA study, VUR, or recurrent UTI underwent a DMSA control study (mean 8m after UTI). Results: DMSA study during febrile UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA studies were not performed due to a good clinical outcome (no VUR, no recurrent UTI). In the remaining 17 patients, follow-up DMSA studies were normal as well. Forty children (26%), who presented focal or diffuse cortical lesions during acute UTI, underwent a DMSA control study. Twenty-six of them presented a normal control DMSA, and 14 (9% of all patients) presented cortical lesions, 10 associated with a high-grade VUR. Fifty-seven children were followed by control DMSA, and no significant correlation between initial and follow-up study was found (κ= 0.250, p<0.007). Conclusion: These results indicate that DMSA study performed during febrile UTI may not be useful as predictor of patient outcome. Voiding cysto urethrography and control DMSA study seem to be more useful to select patients at risk of development of chronic cortical lesions

  15. Development of 99mTc-DMSA for kidney imaging

    International Nuclear Information System (INIS)

    Shafii Khamis; Nurshuhadah Mohd Yusof

    2006-01-01

    In nuclear medicine studies, 99m Tc-Dimercaptosuccinic acid ( 99m Tc-DMSA) has been shown to be an excellent radiopharmaceutical agent for detecting focal abnormalities of the renal cortex in patients. The agent, however, oxidizes readily and must be used within 30 minutes of preparation. The instability of the radiopharmaceutical renders the kit less economical to use. Several factors affecting the labeling yield such as the kit formulation, stannous and stabilizer content were investigated. The radiochemical determination of the radiolabelled product was analyzed using I TLC-SG system developed in methyl ethyl ketone and the radiolabelled 99m Tc-DMSA biological distributions were carried out in female rats. Stability study of the radiolabelled 99m Tc-DMSA was carried out using ascorbic acid as stabilizer. Comparative study was also carried out on both the prepared kit and those obtained commercially. The DMSA kit was successfully developed and the result obtained was found to be comparable to that of the commercially available kit. (Author)

  16. The DMSA scan in paediatric urinary tract infection

    International Nuclear Information System (INIS)

    Ditchfield, M.R.; Nadel, H.R.

    1998-01-01

    The objective of the present paper was to review the use of the dimercaptosuccinic acid (DMSA) scan in urinary tract infection at British Columbia's Children's Hospital to determine the frequency of cortical defects and the association between vesico-ureteric reflux and the presence of cortical defects in children with urinary tract infection. A total of 129 consecutive children with a urinary tract infection referred for a DMSA scan in a 2-year period (January 1992-January 1994) were retrospectively studied. The results were analysed in terms of kidneys, and the incidence of cortical defects was determined. Eighty-eight patients (68%) had a radiographic micturating cysto-urethrogram within 6 months of the DMSA scan, and in this group the relationship of defects with vesico-ureteric reflux was determined. Overall, 81/258 (31%) of kidneys had a cortical defect on a DMSA scan. Of those who had a micturating cysto-urethrogram, 53/176 (30%) kidneys had vesico-ureteric reflux, and of those that had reflux, 21/53 (40%) had a cortical defect on a DMSA scan. In the group of children without reflux, 38/123 (31%) had a cortical defect. Renal cortical scan defects are common findings in paediatric urinary infection, and frequently occur in the absence of vesico-ureteric reflux. These defects represent either established scars or acute pyelonephritis that can proceed to scarring. The micturating cysto-urethro-gram alone is insufficient as a screening modality to identify those kidneys at risk of renal scarring. Copyright (1998) Blackwell Science Pty Ltd

  17. Is the renal uptake of 99mTc-DMSA decreased in microalbuminuric diabetic patient?

    International Nuclear Information System (INIS)

    Kim, Seong Jang; Kim, In Ju; Kim, Yong Ki

    1999-01-01

    Diabetic nephropathy is the most common cause of end stage renal disease and the incidence is progressively increasing. The aim of this study was to investigate the differences of 99m Tc-DMSA renal uptake among diabetic patients with normoalbuminuria, microalbuminuria and overt proteinuria, and then to determine the clinical usefulness of 99m Tc-DMSA in predicting early diabetic nephropathy. 99m Tc-DMSA scan was performed and a total renal uptake of 99m Tc-DMSA was measured in 145 diabetic patients. Patients were divided into 3 groups according to the amount of 24 hour urinary albumin excretion as Group I (normoalbuminuria, 74 cases ), Group II (microalbuminuria, 39 cases), and Group III (overt proteinuria, 32 cases). The differences of 99m Tc-DMSA renal uptake among the 3 groups and the correlation between the renal uptake of 99m Tc-DMSA and other clinical parameters were analyzed. The total renal uptake of 99m Tc-DMSA of Group II (40.8±11.0%) was significantly lower than that of Group I (54.4±6.3%, p 99m Tc-DMSA total renal uptakes correlated negatively with serum creatinine level (r=0.629, p 99m Tc-DMSA total renal uptake of diabetic patients with microalbuminuria was significantly decreased compared with that of patients of normoalbuminuria. Therefore, 99m Tc-DMSA scan can be used as a diagnostic study for early detection of the diabetic nephropathy

  18. Insight into the structures and stabilities of Tc and Re DMSA complexes: A computational study

    International Nuclear Information System (INIS)

    Blanco González, Alejandro; Hernández Valdés, Daniel; García Fleitas, Ariel; Rodríguez Riera, Zalua; Jáuregui Haza, Ulises

    2016-01-01

    Meso-2,3-dimercaptosuccinic acid (DMSA) is used in nuclear medicine as ligand for preparation of radiopharmaceuticals for diagnostic and therapy. DMSA has been the subject of numerous investigations during the past three decades and new and significant information of the chemistry and pharmacology of DMSA complexes have emerged. In comparison to other ligands, the structure of some DMSA complexes is unclear up today. The structures and applications of DMSA complexes are strictly dependent on the chemical conditions of their preparation, especially pH and the ratio of components. A computational study of M-DMSA (M = Tc, Re) complexes has been performed using density functional theory. Different isomers for M(V) and M(III) complexes were study. The pH influence over ligand structures was taken into account and the solvent effect was evaluated using an implicit solvation model. The fully optimized complex syn-endo Re(V)-DMSA shows a geometry similar to the X-ray data and was used to validate the methodology. Moreover, new alternative structures for the renal agent 99mTc(III)-DMSA were proposed and computationally studied. For two complex structures, a larger stability respect to that proposed in the literature was obtained. Furthermore, Tc(V)-DMSA complexes are more stable than the Tc(III)-DMSA proposed structures. In general, Re complexes are more stables than the corresponding Tc ones. (author)

  19. In vitro evaluation and intra-articular administration of biodegradable microspheres containing naproxen sodium.

    Science.gov (United States)

    Bozdağ, S; Caliş, S; Kaş, H S; Ercan, M T; Peksoy, I; Hincal, A A

    2001-01-01

    The dispersion of non-steroidal antiinflammatory drugs (NSAIDs) into biodegradable polymeric matrices have been accepted as a good approach for obtaining a therapeutic effect in a predetermined period of time meanwhile minimizing the side effects of NSAIDs. In the present study, it was aimed to prepare Naproxen Sodium (NS), (a NSAID) loaded microsphere formulation using natural Bovine Serum Albumin (BSA) and synthetic biodegradable polymers such as poly(lactide-co-glycolic acid) (PLGA) (50:50 MW 34,000 and 88,000 Da) for intra-articular administration, and to study the retention of the drug at the site of injection in the knee joint. NS incorporated microspheres were evaluated in vitro for particle size (the mean particle size; for BSA microspheres, 10.0 +/- 0.3 microm, for PLGA microspheres, 9.0 +/- 0.2 and 5.0 +/- 0.1 microm for MW 34,000 and 88,000 Da, respectively), yield value, drug loading, surface morphology and drug release. For in vivo studies, monoarticular arthritis was induced in the left knee joints of rabbits by using ovalbumin and Freund's Complete Adjuvant as antigen and adjuvant. A certain time (4 days) is allowed for the formation of arthritis in the knee joints, then the NS loaded microspheres were injected directly into the articular cavity. At specific time points, gamma scintigrams were obtained to determine the residence time of the microspheres in knee joints, in order to determine the most suitable formulation. This study indicated that PLGA, a synthetic polymer, is more promising than the natural type BSA microspheres for an effective cure of mono-articular arthritis in rabbits.

  20. Controlled delivery of tauroursodeoxycholic acid from biodegradable microspheres slows retinal degeneration and vision loss in P23H rats.

    Directory of Open Access Journals (Sweden)

    Laura Fernández-Sánchez

    Full Text Available Successful drug therapies for treating ocular diseases require effective concentrations of neuroprotective compounds maintained over time at the site of action. The purpose of this work was to assess the efficacy of intravitreal controlled delivery of tauroursodeoxycholic acid (TUDCA encapsulated in poly(D,L-lactic-co-glycolic acid (PLGA microspheres for the treatment of the retina in a rat model of retinitis pigmentosa. PLGA microspheres (MSs containing TUDCA were produced by the O/W emulsion-solvent evaporation technique. Particle size and morphology were assessed by light scattering and scanning electronic microscopy, respectively. Homozygous P23H line 3 rats received a treatment of intravitreal injections of TUDCA-PLGA MSs. Retinal function was assessed by electroretinography at P30, P60, P90 and P120. The density, structure and synaptic contacts of retinal neurons were analyzed using immunofluorescence and confocal microscopy at P90 and P120. TUDCA-loaded PLGA MSs were spherical, with a smooth surface. The production yield was 78%, the MSs mean particle size was 23 μm and the drug loading resulted 12.5 ± 0.8 μg TUDCA/mg MSs. MSs were able to deliver the loaded active compound in a gradual and progressive manner over the 28-day in vitro release study. Scotopic electroretinografic responses showed increased ERG a- and b-wave amplitudes in TUDCA-PLGA-MSs-treated eyes as compared to those injected with unloaded PLGA particles. TUDCA-PLGA-MSs-treated eyes showed more photoreceptor rows than controls. The synaptic contacts of photoreceptors with bipolar and horizontal cells were also preserved in P23H rats treated with TUDCA-PLGA MSs. This work indicates that the slow and continuous delivery of TUDCA from PLGA-MSs has potential neuroprotective effects that could constitute a suitable therapy to prevent neurodegeneration and visual loss in retinitis pigmentosa.

  1. Assessment of relative individual renal function based on DMSA uptake corrected for renal size

    International Nuclear Information System (INIS)

    Estorch, M.; Camacho, V.; Tembl, A.; Mena, I.; Hernandez, A.; Flotats, A.; Carrio, I.; Torres, G.; Prat, L.

    2002-01-01

    Decreased relative renal DMSA uptake can be a consequence of abnormal kidney size, associated with normal or impaired renal function. The quantification of relative renal function based on DMSA uptake in both kidneys is an established method for the assessment of individual renal function. Aim: To assess relative renal function by means of quantification of renal DMSA uptake corrected for kidney size. Results were compared with relative renal DMSA uptake without size correction, and were validated against the absolute renal DMSA uptake. Material and Methods: Four-hundred-forty-four consecutive patients (147 adults, mean age 14 years) underwent a DMSA study for several renal diseases. The relative renal function, based on the relative DMSA uptake uncorrected and corrected for renal size, and the absolute renal DMSA uptake were calculated. In order to relate the relative DMSA uptake uncorrected and corrected for renal size with the absolute DMSA uptake, subtraction of uncorrected (SU) and corrected (SC) relative uptake percentages of each pair of kidneys was obtained, and these values were correlated to the matched subtraction percentages of absolute uptake (SA). If the individual relative renal function is normal (45%-55%), the subtraction value is less or equal to 10%. Results: In 227 patients (51%) the relative renal DMSA uptake value was normal either uncorrected or corrected for renal size (A), and in 149 patients (34%) it was abnormal by both quantification methods (B). Seventy-seven patients (15%) had the relative renal DMSA uptake abnormal only by the uncorrected method (C). Subtraction value of absolute DMSA uptake percentages was not significantly different of subtraction value of relative DMSA uptake percentages corrected for renal size when relative uncorrected uptake was abnormal and corrected normal. where * p<0.0001, and p=NS. Conclusion: When uncorrected and corrected relative DMSA uptake are abnormal, the absolute uptake is also impaired, while when

  2. A comparative study of 99Tcm (V)-DMSA imaging with histopathological examination in ovarian neoplasms

    International Nuclear Information System (INIS)

    Zhao Xinming; Wang Jianfang; Xu Fang; Yin Jie; Wei Lanxiu; Sun Li

    1999-01-01

    Objective: To assess the clinical value of 99 Tc m (V)-Dmsa imaging in detecting the ovarian and the pelvic cavity neoplasms. Methods: 99 Tc m (V)-DMSA imaging was performed on 24 patients with diagnosed ovarian neoplasms which were pathologically confirmed after operation. Results: 14 of the 15 patients with malignant ovarian tumors had positive 99 Tc m (V)-DMSA scintigraphy. However, 7 of 9 cases with benign ovarian tumors had negative 99 Tc m (V)-DMSA scintigraphy. The sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, false negative rate, and accuracy of 99 Tc m (V)-DMSA imaging for detecting malignant ovarian tumors were 93.33%, 77.78%, 87.50%, 87.50%, 14.29%, 6.67% and 87.50%, respectively. Conclusions: 99 Tc m (V)-DMSA imaging is of important value in detecting malignant and benign ovarian and pelvic tumors

  3. Humoral Immune Response Induced by PLGA Micro Particle Coupled Newcastle Disease Virus Vaccine in Chickens

    Directory of Open Access Journals (Sweden)

    Sanganagouda K

    2014-02-01

    Full Text Available This experiment was conducted for evaluating the humoral immune responses induced by Poly Lactide-co-Glycolide Acid (PLGA microspheres coupled inactivated Newcastle Disease Virus (NDV vaccine in comparison to an ‘in-house’ prepared inactivated and a live commercial vaccine. PLG microparticles containing inactivated NDV were prepared by a double emulsion technique based on solvent evaporation method. The size of the NDV coupled PLG microparticles was determined by Electron Microscopy. NDV coupled PLG microparticles were spherical having smooth surface, hollow core inside with no pores on the surface. The experiment was conducted in four groups of chickens (n=15. The encapsulation efficiency of NDV coupled PLG microparticles was determined by protein estimation and HA activity in elute. The mean (± SE size of PLG microspheres was found to be 2.409 ± 0.65 µm. The mean percent of encapsulation efficiency of PLG microspheres coupled to NDV was assessed based on the total protein content and HA activity in elute was found to be 8.03 ± 0.50 and 12.5 ± 0.00, respectively. In conclusion, the results of the experiment showed that PLGA coupled NDV vaccine elicited stronger and prolonged humoral immune response in chickens, in comparison to the other tested vaccines, as assessed by haemagglutination inhibition and enzyme linked immuno sorbent asaay titers.

  4. Studies on the evaluation of renal function in hydronephrosis with 99mTc-DMSA renal uptake

    International Nuclear Information System (INIS)

    Takeda, Masayuki; Katayama, Yasushi; Takahashi, Hitoshi; Sato, Shotaro

    1988-01-01

    99m Tc-dimercaptosuccinic acid renal uptake (DMSA uptake) was measured in patients with hydronephrosis and we obtained the following conclusions. 1. Grades of hydronephrosis on IVP according to Oka's classification were compared with DMSA uptake. In 73 adult patients, the grade of hydronephrosis paralleled DMSA uptake well, but in 20 children it did not. 2. The changes of DMSA uptake pre- and post-nephrostomy were measured in 21 kidneys in 19 cases with congenital hydronephrosis. DMSA uptake of 7 infantile kidneys significantly increased post-nephrostomy, but in the cases over 1 year old significantly decreased after nephrostomy. DMSA uptake of the contralateral kidney significantly increased after nephrostomy in infants, but it did not change in the group over 1 year old. 3. In 15 kidneys of 13 cases with nephrostomy, DMSA uptake during closure and after opening of the nephrostomy catheter and DMSA uptake due to the radioisotope (RI) accumulated in the renal collecting system were measured. In the group over 1 year old, DMSA uptake decreased after opening nephrostomy nearly all and the extent of the decrease almost agreed with DMSA uptake due to RI accumulated in the renal collecting system. But in infants, DMSA uptake increased after opening nephrostomy in most cases and the extent of the change in DMSA uptake did not agree with DMSA uptake due to RI accumulated in the renal collecting system. (author)

  5. Tc-99m DMSA renal uptake: influence of biochemical and physiologic factors

    International Nuclear Information System (INIS)

    Yee, C.A.; Lee, H.B.; Blaufox, M.D.

    1981-01-01

    Thirty-eight female Sprague-Dawley rats were studied to determine the effects of (a) tubular blockade and (b) commonly encountered changes in hydration and acid-base balance, on the urinary excretion and renal localization of Tc-99m dimercaptosuccinic acid (DMSA). Ten additional rats were studied to quantitate the in vivo protein binding of Tc-99m DMSA, and a final group of 12 animals was used to quantitate DMSA distribution in animals with diminished functional renal mass. Both osmotic diuresis and dehydration by water deprivation for 24 hr resulted in a plasma clearance of DMSA slower than in control animals. Acid-base imbalances significantly affected the renal accumulation of DMSA, and acidosis was associated with markedly increased background due to increased liver accumulation. The protein-bound portion of Tc-99m DMSA in the plasma was high, reaching 89% within the first 5 min, and rising very slightly (n.s.) with time. The unbound portion of DMSA had a plasma clearance slightly higher than the GFR. Ablation of large amounts of renal tissue, resulting in significant decreases in GFR, did not significantly affect the renal localization of DMSA in the intact portions of the kidneys. These data demonstrate that commonly encountered changes in acid-base balance and hydration will significantly alter the biologic distribution of Tc-99m DMSA. These factors should be controlled when carrying out clinical studies

  6. Automatic classification of DMSA scans using an artificial neural network

    Science.gov (United States)

    Wright, J. W.; Duguid, R.; Mckiddie, F.; Staff, R. T.

    2014-04-01

    DMSA imaging is carried out in nuclear medicine to assess the level of functional renal tissue in patients. This study investigated the use of an artificial neural network to perform diagnostic classification of these scans. Using the radiological report as the gold standard, the network was trained to classify DMSA scans as positive or negative for defects using a representative sample of 257 previously reported images. The trained network was then independently tested using a further 193 scans and achieved a binary classification accuracy of 95.9%. The performance of the network was compared with three qualified expert observers who were asked to grade each scan in the 193 image testing set on a six point defect scale, from ‘definitely normal’ to ‘definitely abnormal’. A receiver operating characteristic analysis comparison between a consensus operator, generated from the scores of the three expert observers, and the network revealed a statistically significant increase (α quality assurance assistant in clinical practice.

  7. Technetium-99m DMSA preparation: Trivial issues causing severe problems

    International Nuclear Information System (INIS)

    Kumar, V.

    1997-01-01

    Urinary tract infection (UTI) in children involving renal parenchyma, upper collecting system or bladder is one of the major causes for consideration in the diagnosis and management of paediatric nuclear medicine. Acute pyelonephritis is one of the prime causes of morbidity associated with urinary tract infection in children which can lead to progressive renal damage. Technetium-99m dimercaptosuccinic acid (DMSA) is used extensively for the assessment of UTI in paediatrics. The radiopharmaceutical preparation could be influenced by several factors, most of them are trivial, but invariably have severe impact on the quality of the scintiphotographs. This communication is mainly to highlight some of the issues related to 99 mTc-DMSA preparation and the possible precautionary measures that need to be taken to obviate unwarranted problems. (author)

  8. Variability in the interpretation of DMSA scintigraphy after urine infection

    International Nuclear Information System (INIS)

    Craig, J.; Howman-Giles, R.; Uren, R.; Irwig, L.; Bernard, E.; Knight, J.; Sureshkumar, P.; Roy, L.P.

    1997-01-01

    Full text: This study investigated the extent of and potential reasons for interpretation disagreement of 99m Tc-DMSA scans after urine infection in children. Methods: 441 scans were selected from children with first urine infection (UTI) from 1993-1995. 294 scans were performed at a median time of seven days after UTI and 147 in children free from infection over one year follow-up. Two nuclear medicine physicians independently reported according to whether renal abnormality was present or absent and used the four level grading system described by Goldraich: grade 1-no more than two cortical defects; grade 2 -more than 2 defects; grade 3-diffuse reduction in uptake with or without defects; grade 4 -shrunken kidney <10% function. Indices for variability used were the percentage of agreement and kappa statistic, expressed as a percentage. For the grading scale used, both measures were weighted with integers representing the number of categories from perfect agreement. Disagreement was analysed for children, kidneys and kidney zones. Results: There was agreement in 86 per cent (kappa 69%) for the normal-abnormal DMSA scan dichotomy, the weighted agreement was 94 per cent (kappa 82%) for the grading scale. Disagreement of DMSA scan interpretation ≥ two grades was present in three cases (0.7%). The same level of agreement was present for the patient, kidney and kidney zones comparisons. Agreement was not influenced by age or the timing of scintigraphy after urine infection. Conclusion: Two experienced physicians showed good agreement in the interpretation DMSA scintigraphy in children after urine infection and using the grading system of Goldraich

  9. Radiopharmaceuticals of DTPA, DMSA and EDTA labeled with holmium-166

    International Nuclear Information System (INIS)

    Rahman, M.; Matsouka, H.; Takami, S.; Terunuma, K.

    2001-01-01

    DTPA, DMSA and EDTA were labelled with 166 Ho of low specific activity, 250-275mCi/mg of Ho, produced from holmium oxide by the 165 Ho(n, g) 166 Ho reaction at a neutron flux of about 10 14 n.cm -2 .s -1 . Three pH ranges were selected in the study, viz. 2-3, 3-3.5 and 5-6. The labelling reactions were studied as chloride and nitrate solutions in aqueous and saline media at 30 min and 20-24 h of reaction. DTPA was labelled over 99, DMSA at about 90 and EDTA at 100.0% with 166 Ho. The complexes were found stable at all times of investigation. A beta chromatogram scanner was used to study by TLC the labelling reactions of DTPA and DMSA with the nuclide and by PC those of EDTA. A biodistribution study in three rats injected intravenous with a saline solution of 166 HoCl 3 [DTPA] at pH5.1 showed an initial uptake in blood, kidney and lung after 30 minutes. After four hours the complex was found to have cleared from blood and lung, and localized 100% in kidney. It was stable in vivo in the kidney after 24 hours. The g spectrum analysis did not show the formation of any impurity except the four characteristic g energies of 166 Ho. (author)

  10. Alteration of 99mTc-DMSA biodistribution in glomerulonephritis

    International Nuclear Information System (INIS)

    Rajic, M.; Bogicevic, M.; Ilic, S.; Vlajkovic, M.; Antic, S.; Mitic, B.; Avramovic, M.; Mitic-Zlatovic, M.; Stefanovic, V.

    2002-01-01

    The aim of this study was to assess the relation between 99T c-DMSA biodistribution and its reliability as a marker of renal function in patients with glomerular kidney diseases. Sixty-seven patients involved in this study were classified into two groups according to 99T c-DTPA clearance and serum creatinine values: the 1. group consisted of 42 patients without renal failure while the 2nd group included 25 patients with renal failure. 99T c-DMSA biodistribution was determined by measuring kidney, blood and urine activity at 2 h and 4 h. The results, compared with those of 23 healthy volunteers, indicated the quantitative alteration of 99T c-DMSA distribution in both glomerulonephritis patient groups. In reference to the control mean values of 2 h and 4 h, in patients without renal failure, kidney activity was found decreased to 52% and 57%, while the blood activity increase of 37% and 44% was recorded together with the urine activity increase of 38% and 23%. In patients with renal failure the alterations of renal and blood activity were more remarkable, but the urine loss was found to be unchanged. It is suggested that these biodistribution changes originate mainly from tubular impairment. However, in glomerulonephritis patients, altered glomerular filtration might considerably affect biodistribution of this radiopharmaceutical and limits its suitability for precise quantitative estimation of renal function. (author)

  11. 99mTc DMSA scintigraphic findings in renal tuberculosis

    International Nuclear Information System (INIS)

    Moon, Tae Yong; Kim, Kun Il; Yoon, Chi Soon; Lee, Suck Hong; Kim, Byung Soo

    1993-01-01

    Evaluations of residual renal function and the therapeutic effectiveness in renal tuberculosis have largely been dependent on intravenous pyelogram or Contrast-CT scan, even though, exact renal functions are not evaluate with there methods. 99m Tc- DMSA is a radiopharmaceutical that is trapped in the functioning tubular cells of the kidney and therefore, quantitative renal function could be evaluated by insuring the counts of renal radioactivity and concomitant evaluation of renal morphology could be passable with the analog images of the radioactivity. The authors retrospectively analyzed 99mTc-DMSA scans of 75 kidneys of 67 patients with confirmed renal tuberculosis. We classified the morphologies of tuberculous kidneys as 6 types. We classified the morphologies of tuberculous kidneys as 6 types such as the type with small cortical defect, with parenchymal ulcerocavernous lesions, ulcerocavernous fistula to pelvis, mass-like defects, contracted kidney with ureter visualization, and the type with non visualization of kidney, corresponding to the characters of renal tuberculous pathogenesis with abscess formation, ulcerocavernous fistula, and fibrosis, and corresponding to the renal anatomy with parenchyma, and pelvocalyceal collecting system. Their mean residual renal functions measured with 99mTc-DMSA uptake rates were 19.0%,18.4%, 7.9%, 12%, 4.1%, 3.4% respectively

  12. Renal parenchymal damage on DMSA-scintigraphy in pelviureteric obstruction

    International Nuclear Information System (INIS)

    Kullendorff, C.M.; Evander, E.

    1989-01-01

    During a 1.5 year period 21 children were investigated with 99-m-technetium dimercaptosuccini acid (DMSA) before operation for hydronephrosis due to pelviureteric obstruction. The age at investigation was 0.2-11.5 years. Fourty-two kidneys were examined. Hydronephrosis existed on the right side in 8 cases, left side in 9 and bilateral in 4 cases. Seventeen kidneys had no obstruction. The scintigraphy was interpreted as normal in 19 kidneys. Decreased isotope uptake was found in 23 kidneys and localized to the upper pole area in 19 kidneys. middle-lateral part in 7, lower pole area in 15 and the middle-medial part in 12 kidneys. There were no predominance for any part of the kidney to be affected by parenchymal damage. In 8 children investigated before the age of 1 year, 4 of 10 hydronephrotic kidneys revealed normal DMSA scintigram. DMSA scintigraphy delineates functioning renal parenchyma. It can be recommended as a routine method for evaluation of the renal parenchyma before surgery and for follow up studies in all ages of childhood

  13. Self-Assembly of pH-Responsive Microspheres for Intestinal Delivery of Diverse Lipophilic Therapeutics.

    Science.gov (United States)

    Zhou, Xing; Zhao, Yang; Chen, Siyu; Han, Songling; Xu, Xiaoqiu; Guo, Jiawei; Liu, Mengyu; Che, Ling; Li, Xiaohui; Zhang, Jianxiang

    2016-08-08

    Targeted delivery of therapeutics to the intestine is preferred for the management of many diseases due to its diverse advantages. Currently, there are still challenges in creating cost-effective and translational pH-responsive microspheres for intestinal delivery of various hydrophobic drugs. Herein we report a multiple noncovalent interactions-mediated assembly strategy in which carboxyl-bearing compounds (CBCs) are guest molecules, while poly(N-isopropylacrylamide) (PNIPAm) serves as a host polymer. Formation of microparticles and therapeutic packaging can be achieved simultaneously by this assembly approach, leading to well-shaped microspheres with extremely higher drug loading capacity as compared to microspheres based on two FDA-approved materials of poly(d,l-lactide-co-glycolide) (PLGA) and an enteric coating polymer EudragitS 100 (S100). Also, carboxyl-deficient hydrophobic drugs can be effectively entrapped. These assembled microspheres, with excellent reconstitution capability as well as desirable scalability, could selectively release drug molecules under intestinal conditions. By significantly enhancing drug dissolution/release in the intestine, these pH-responsive assemblies may notably improve the oral bioavailability of loaded therapeutics. Moreover, the assembled microspheres possessed superior therapeutic performance in rodent models of inflammation and tumor over the control microspheres derived from PLGA and S100. Therapy with newly developed microspheres did not cause undesirable side effects. Furthermore, in vivo evaluation in mice revealed the carrier material PNIPAm was safe for oral delivery at doses as high as 10 g/kg. Collectively, our findings demonstrated that this type of pH-responsive microsphere may function as superior and translational intestine-directed delivery systems for a diverse array of therapeutics.

  14. 99m-Tc DMSA scintigraphy and color/power doppler sonography for children pyelonephritis diagnosis and follow-up

    International Nuclear Information System (INIS)

    Hitzel, A.; Manrique, A.; Gardin, I.; Vera, P.; Hitzel, A.; Dacher, J.N.; Manrique, A.; Menard, J.F.; Gardin, I.; Vera, P.; Dacher, J.N.; Liard, A.; Menard, J.F.

    2004-01-01

    Early diagnosis of acute pyelonephritis is essential to avoid scarring development. This study was performed to evaluate capabilities of color/doppler sonography to detect pyelonephritis and to predict scarring when compared with 99m Tc-DMSA scintigraphy. Fifty-seven children were evaluated during pyelonephritis: biology (CRP, creatinine, blood formula), color/power doppler sonography and 99m Tc-DMSA scintigraphy (DMSA1). 7 ± 2 months later, follow-up consisted in biological tests and a 99m 'Tc-DMSA scintigraphy (DMSA2). During pyelonephritis, body temperature, CRP value and neutrophil counts were significantly higher in patients with an abnormal DMSA1 but not in patients with abnormal doppler sonography. When compared with DMSA1, doppler sonography sensitivity and specificity were 80% and 81% respectively. DMSA1 and doppler sonography were concordant in 86% of children with a pyelonephritis. At follow-up, all clinical et biological parameters were normalized. DMSA2 was abnormal in 51% of children. When compared with DMSA2, positive and negative predictive values for scarring of doppler sonography were 57% and 75% respectively. DMSA 1, positive and negative predictive values for scarring were 62% and 100%. In conclusion, color/power doppler sonography is a reliable tool for pyelonephritis diagnosis, but its predictive value for scarring is poor. Negative predictive value of DMSA scintigraphy is excellent. (author)

  15. Renal handling of technetium-99m DMSA: Evidence for glomerular filtration and peritubular uptake

    International Nuclear Information System (INIS)

    de Lange, M.J.; Piers, D.A.; Kosterink, J.G.; van Luijk, W.H.; Meijer, S.; de Zeeuw, D.; van der Hem, G.K.

    1989-01-01

    The finding of an enhanced excretion of [ 99m Tc]dimercaptosuccinic acid (DMSA) in patients with tubular reabsorption disorders prompted us to investigate the role of filtration in the renal handling of [ 99m Tc]DMSA. Our studies in human serum indicated that binding to serum proteins was approximately 90%. Chromatography of human urine and studies in rats showed that the complex was excreted unaltered into the urine. Renal extraction of [ 99m Tc]DMSA in a human volunteer was 5.8%. Continuous infusion of [ 99m Tc]DMSA in 13 individuals with normal renal function gave the following results (mean +/- s.d.): plasma clearance of [ 99m Tc]DMSA 34 +/- 4 ml/min, urinary clearance of [ 99m Tc]DMSA 12 +/- 3 ml/min. The calculated filtered load of [ 99m Tc]DMSA closely resembled the urinary clearance, whereas the plasma clearance was about three times faster. This indicates that peritubular uptake accounts for approximately 65% and filtration for approximately 35% of the renal handling of [ 99m Tc]DMSA

  16. Renal damage detected by DMSA, despite normal renal ultrasound, in children with febrile UTI.

    Science.gov (United States)

    Bush, N C; Keays, M; Adams, C; Mizener, K; Pritzker, K; Smith, W; Traylor, J; Villanueva, C; Snodgrass, W T

    2015-06-01

    2011 American Academy of Pediatrics guidelines recommended renal-bladder ultrasound (RBUS) as the only evaluation after febrile urinary tract infection (FUTI) in infants aged 2-24 months. We determined the sensitivity, specificity, and false negative rate of RBUS to identify DMSA-detected renal damage in this age group as well as in older children. Consecutive patients referred to pediatric urology with a history of FUTI underwent DMSA ≥ 3 months after FUTI. Abnormal RBUS was defined as: Society of Fetal Urology hydronephrosis grades I-IV; hydroureter ≥ 7 mm; renal scar defined as focal parenchymal thinning; and/or size discrepancy ≥ 1 cm between kidneys. Abnormal DMSA was presence of any focal uptake defects and/or split renal function 24 months. RBUS had poor sensitivity (34%) and low positive predictive value (47%) to identify patients with renal damage. 99/149 (66%) children with renal damage on DMSA had normal RBUS. After FUTI, 66% of children with reduced renal function and/or renal cortical defects found by DMSA scintigraphy had a normal RBUS. Since abnormal DMSA may correlate with increased risk for VUR, recurrent FUTI and renal damage, our data suggest RBUS alone will fail to detect a significant proportion of patients at risk. The data suggest that imaging after FUTI should include acute RBUS and delayed DMSA, reserving VCUG for patients with abnormal DMSA and/or recurrent FUTI. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  17. Acute pyelonephritis in pediatric age: comparative study between power Doppler ultrasound scan and DMSA

    International Nuclear Information System (INIS)

    Muro, M. D.; Sanguesa, C.; Otero, M. C.; Piqueras, A. I.; Lloret, M. T.

    2002-01-01

    To evaluate the usefulness of power Doppler (PD) Ultrasound Scan in the study of acute pyelonephritis (APN). To compare ultrasound scan results with those obtained with renal gammagraphy (DMSA). To relate the findings to the clinical criteria and to determine the presence of vesicoureteral reflux (VUR) in the serial micturition cystography (SMC). Prospective study of 92 patients (ages between 1 month and 10 years) with suspected clinical PNA. All children were initially subjected to PD ultrasound scan and DMSA. Those under 3 years old were also subjected to SMC for the study of VUR. PNA in the PD ultrasound scan was manifested by decrease in vascularisation and in the DMSA by decrease in caption in the affected zones. 87 renal units (RU) with PNA foci were detected. Conformity between the PD ultrasound scan and DMSA was 157 RU (92%): 52 positives, 22 negatives with PNA and 83 normal RU. The sensitivities of PD and DMSA were 65.5% and 69.0%. 51 SMC were performed, with VUR being detected in 18 (13 bilateral and 5 unilateral), in which the sensitivities of PD and DMSA were 65.5% and 69.0%. 51 SMC were performed, with VUR being detected in 18 (13 bilateral and 5 unilateral), in which the sensitivities of PD and DMSA were 80% and 85%, respectively. Mode B ultrasound scan and PD can replace DMSA in the initial study of PPNA. It is non-invasive, simple, economical and just as reliable as DMSA in expert hands. it can also postpone by up to 6 months the need to perform DMSA for detection of permanent renal damage. (Author) 22 refs

  18. Metallic coating of microspheres

    International Nuclear Information System (INIS)

    Meyer, S.F.

    1980-01-01

    Extremely smooth, uniform metal coatings of micrometer thicknesses on microscopic glass spheres (microspheres) are often needed as targets for inertial confinement fusion (ICF) experiments. The first part of this paper reviews those methods used successfully to provide metal coated microspheres for ICF targets, including magnetron sputtering, electro- and electroless plating, and chemical vapor pyrolysis. The second part of this paper discusses some of the critical aspects of magnetron sputter coating of microspheres, including substrate requirements, the sticking of microspheres during coating (preventing a uniform coating), and the difficulties in growing the desired dense, smooth, uniform microstructure on continuously moving spherical substrates

  19. Biodistribution of Ru-97-labeled DTPA, DMSA and transferrin

    International Nuclear Information System (INIS)

    Som, P.; Oster, Z.H.; Fairchild, R.G.; Atkins, H.L.; Brill, A.B.; Gil, M.C.; Srivastava, S.C.; Meinken, G.E.; Goldman, A.G.; Richards, P.

    1980-01-01

    Ruthenium-97 is being produced at the Brookhaven Linac Isotope Producer (BLIP). The favorable physical properties of Ru-97 and chemical reactivity of ruthenium offer a potential for using this isotope to label compounds useful for delayed scanning. Diethylenetriamine pentaacetic acid (DTPA), 2,3-Dimercaptosuccinic acid (DMSA), and Transferrin (TF) were labeled with Ru-97-chloride. Ru-97-DTPA and In-111-DTPA, injected intravenously, showed similar organ distribution, kinetics, and more than 80% excretion by 0.5 h. Ru-97-DTPA and In-111-DTPA injected into the cisterna magna of dogs showed similar kinetics in brain, blood, and urinary bladder. The energy deposited by 1 mCi In-111-DTPA is twice that from 1 mCi Ru-97-DTPA. High quality camera images of the CSF space in the dog were obtained with both isotopes. Ru-97-DMSA was prepared with and without the addition of SnCl 2 .2H 2 O. Tin-free DMSA was rapidly excreted via the kidneys, whereas for maximum cortical deposition, the tin-containing preparation was superior. This compound is suitable for delayed imaging of both normal and impaired kidneys. Tissue distribution studies were performed in abscess-bearing rats with Ru-97-transferrin. Although blood levels were higher than with Ga-67-citrate, the abscess had twice as much Ru-97-TF as Ga-67-citrate and the Ru-97 muscle activity was one-third that of Ga-67. Imaging of abscess-bearing rabbits with Ru-97-TF visualized the abscesses as early as 1/2 hr after injection. Since the initial images visualize the abscess so clearly and since the TF portion of the compound binds to the abscess, Tc-99m-TF is being studied for the same purpose. Ru-97-labeled compounds are a promising replacement for In-111 and possibly also for Ga-67 compounds with the advantages of lower radiation dose and high quality image

  20. PEG modulated release of etanidazole from implantable PLGA/PDLA discs.

    Science.gov (United States)

    Wang, Fangjing; Lee, Timothy; Wang, Chi-Hwa

    2002-09-01

    In this work, etanidazole (one type of hypoxic radiosensitizer) is encapsulated into spray dried poly(D),L-lactide-co-glycolide) (PLGA) microspheres and then compressed into discs for controlled release applications. Etanidazole is characterized by intracellular glutathione depletion and glutathione transferases inhibition, thereby enhancing sensitivity to radiation. It is also cytotoxic to tumor cells and can chemosensitize some alkylating agents by activating their tumor cell killing capabilities. We observed the release characteristics of etanidazole in the dosage forms of microspheres and discs, subjected to different preparation conditions. The release characteristics, morphology changes, particle size, and encapsulation efficiency of microspheres are also investigated. The release rate of etanidazole from implantable discs (13 mm in diameter, 1 mm in thickness, fabricated by a press) is much lower than microspheres due to the reduced specific surface. After the initial burst of 1% release for the first day, the cumulative release within the first week is less than 2% until a secondary burst of release (caused by polymer degradation) occurs after one month. Some key preparation conditions such as drug loadings, disc thickness and diameter, and compression pressure can affect the initial burst of etanidazole from the discs. However, none of them can significantly make the release more uniform. In contrast, the incorporation of polyethylene glycol (PEG) can greatly enhance the release rate of discs and also reduces the secondary burst effect, thereby achieving a sustained release for about 2 months.

  1. The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood

    International Nuclear Information System (INIS)

    Supavekin, S.; Pravisithikul, N.; Kutanavanishapong, S.; Chiewvit, S.; Surapaitoolkorn, W.

    2013-01-01

    The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI. A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97±1.57 years (0.02-7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI. Of 67 children, 17 (25.4%), 23 (34.3%) and 20 (29.9%) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and <0.001 in patients and at p values 0.024 and <0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I-III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV-V) had significant correlations with abnormal DMSA renal scintigraphy at p values <0.001 and <0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2%) developed persistent renal scarring. Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first

  2. Renal function assessed by 99mTc-DMSA scintigraphy before and after percutaneous nephrostolithotripsy (PNL)

    International Nuclear Information System (INIS)

    Sakurai, Masaki; Hioki, Takuichi; Kitano, Tokio; Nakagawa, Tsuyoshi; Yamaguchi, Nobuo; Kawamura, Juichi

    1988-01-01

    99m Tc-DMSA scintigraphy was carried out in 43 patients with unilateral renal stones before and after PNL. This study was repeated about one year after PNL in 12 patients. DMSA renal uptake was calculated two hours after injection of 99m Tc-DMSA. The study was performed using the dual type gamma camera. The renal function was assessed by the formula : 99m Tc-DMSA renal uptake of the operated side/ 99m Tc-DMSA renal uptake of the contralateral side. The change (ratio before/after PNL) x 100 was regarded as the percent change of renal function. Local abnormalities in the 99m Tc-DMSA renal scintigram after PNL were observed in 15 patients. The renal function decreased significantly to 95.8 ± 8.7 % from the base line 4 - 8 weeks after PNL. The renal function improved significantly to 98.6 ± 14.7 % from 92.1 ± 11.9 % in 12 patients about one year after PNL. It is concluded that although the renal function slightly decreased 4 - 8 weeks after PNL, it is expected to improve within 1 year after PNL. 99M Tc-DMSA scintigraphy is a useful adjunct to evaluate the renal function before and after PNL. (author)

  3. PLGA-based microcarriers induce mesenchymal stem cell chondrogenesis and stimulate cartilage repair in osteoarthritis.

    Science.gov (United States)

    Morille, Marie; Toupet, Karine; Montero-Menei, Claudia N; Jorgensen, Christian; Noël, Danièle

    2016-05-01

    In the present study, we aimed at evaluating the ability of novel PLGA-P188-PLGA-based microspheres to induce the differentiation of mesenchymal stem/stromal cells (MSC) into chondrocytes. To this aim, we tested microspheres releasing TGFβ3 (PAM-T) in vitro and in situ, in a pathological osteoarthritic (OA) environment. We first evaluated the chondrogenic differentiation of human MSCs seeded onto PAM-T in vitro and confirmed the up-regulation of chondrogenic markers while the secretome of the cells was not changed by the 3D environment. We then injected human MSC seeded onto PAM-T in the knee joints of mice with collagenase-induced OA. After 6 weeks, histological analysis revealed that formation of a cartilage-like tissue occurred at the vicinity of PAM-T that was not observed when MSCs were seeded onto PAM. We also noticed that the endogenous articular cartilage was less degraded. The extent of cartilage protection was further analysed by confocal laser microscopy. When MSCs seeded onto PAM-T were injected early after OA induction, protection of cartilage against degradation was evidenced and this effect was associated to a higher survival of MSCs in presence of TGFβ3. This study points to the interest of using MSCs seeded onto PAM for cartilage repair and stimulation of endogenous cartilage regeneration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Automatic classification of DMSA scans using an artificial neural network

    International Nuclear Information System (INIS)

    Wright, J W; Duguid, R; Mckiddie, F; Staff, R T

    2014-01-01

    DMSA imaging is carried out in nuclear medicine to assess the level of functional renal tissue in patients. This study investigated the use of an artificial neural network to perform diagnostic classification of these scans. Using the radiological report as the gold standard, the network was trained to classify DMSA scans as positive or negative for defects using a representative sample of 257 previously reported images. The trained network was then independently tested using a further 193 scans and achieved a binary classification accuracy of 95.9%. The performance of the network was compared with three qualified expert observers who were asked to grade each scan in the 193 image testing set on a six point defect scale, from ‘definitely normal’ to ‘definitely abnormal’. A receiver operating characteristic analysis comparison between a consensus operator, generated from the scores of the three expert observers, and the network revealed a statistically significant increase (α < 0.05) in performance between the network and operators. A further result from this work was that when suitably optimized, a negative predictive value of 100% for renal defects was achieved by the network, while still managing to identify 93% of the negative cases in the dataset. These results are encouraging for application of such a network as a screening tool or quality assurance assistant in clinical practice. (paper)

  5. Tc-DMSA (V) imaging for subacute back pain

    International Nuclear Information System (INIS)

    Baldey, A.; Salehi, N.; Thomas, C.; Schlict, S.; Lichtenstein, M.

    1997-01-01

    Full text: Background: Low back pain is a common disabling illness in the Western world creating $25 billion medical costs in the USA alone. The overall outcome of back pain has not been shown to be influenced by the currently available treatments. Diagnostic techniques are also imprecise. Some back pain may be due to minor currently undetectable ligamentous tears which generate a scarring fibrotic reaction. Aim: To detect minor ligamentous tears and ultimately assess steroid injection treatment using scintigraphic techniques. Methods: Technetium [valency (5)] dimercaptosuccinic acid [ 99m Tc (V) DMSA] is a radiopharmaceutical which has been demonstrated to accumulate in fibrotic tissues 2- Technetium-99m (V) DMSA single photon emission computed tomographic (SPECT) scans were performed in ten patients with subacute (2-12 months duration) back pain. These scans were compared to SPECT bone scans also performed in these patients. Results: One patient was excluded post imaging due to likely infection or tumour. Of the nine patients remaining, five showed lesions presumed to be due to healing scars. Hence new abnormalities are detectable by this technique. Conclusion: Accrual is continuing but definitive results will not be available until the clinical results of scan directed steroid injections are evaluated

  6. DMSA 99mTc an old molecule for a new future

    International Nuclear Information System (INIS)

    Moretti, J.L.

    1992-01-01

    This lecture is concerned with the use of DMSA 99m Tc in nephrology. It described human pharmaceutic and clinical applications of this radiopharmaceutical. As DMSA 99m Tc concentrates actively in the proximal convoluted tubule, it gives an image of functional renal mass. Its integrity is dependent upon several factors, predominantly intrarenal blood flow and intact enzyme function. Its role in pathology is clear in pyelonephritis, hydronephrotic kidney and pediatric diseases. The irradiation dosimetry of DMSA 99m Tc is well established, the critical organ is the renal cortex which receives between 15 and 250 mGy per MBq. Dosimetry remains favourable for the patients if compared with intravenous urography

  7. Guidelines on {sup 99m}Tc-DMSA scintigraphy in children; Empfehlungen zur Durchfuehrung der DMSA-Szintigraphie bei Kindern

    Energy Technology Data Exchange (ETDEWEB)

    Piepsz, A. [CHU St. Pierre, Bruessel (Belgium); Colarinha, P. [Instituto Portugues de Oncologia, Lissabon (Portugal); Gordon, I. [Great Ormend Street Hospital for Children, London (United Kingdom); Hahn, K. [Muenchen Univ. (Germany). Klinik fuer Nuklearmedizin; Olivier, P. [CHU Vandoeuvre, Nancy (France); Roca, I.; Velzen, J. van [Hospital Vall d' Hebron, Barcelona (Spain); Sixt, R. [The Queen Silvia Children' s Hospital, Goeteborg (Sweden)

    2000-11-01

    The guidelines are intended to help nuclear medical teams in their daily routine. The guidelines give information relating to indications, imaging parameters, data evaluation and interpretation. The guidelines are in line with the opinions of the Paediatric Committee of EANM and hence focus on approaches adopted in Europe, e.g. as regards selection of the radiopharmaceuticals or activity levels applied. The guidelines should be seen in the context of local quality standards and regulatory requirements. (orig./CB) [German] Zweck dieser Empfehlung ist es, dem Nuklearmedizinischen Team bei Tc-DMSA-Szintigraphie von Kindern Hilfestellung fuer die taegliche Routinepraxis zu geben. Die Empfehlung enthaelt Informationen ueber Indikationen, Aufnahmeparameter, Auswertung und Interpretation der DMSA-Szintigraphie bei Kindern. Die vorliegende Empfehlung fasst die Meinung des Paediatric Committee der EANM zusammen und ist daher mehr auf die Europaeische Vorgehensweise, z.B. bei der Wahl des Radiopharmazeutikums und den verwendeten Aktivitaetsmengen, ausgerichtet. Sie sollte immer in Zusammenhang mit lokalen Qualitaetsstandards und Vorschriften gesehen werden. (orig.)

  8. Hydrogel-PLGA delivery system prolongs 2-methoxyestradiol-mediated anti-tumor effects in osteosarcoma cells.

    Science.gov (United States)

    Maran, Avudaiappan; Dadsetan, Mahrokh; Buenz, Colleen M; Shogren, Kristen L; Lu, Lichun; Yaszemski, Michael J

    2013-09-01

    Osteosarcoma is a bone tumor that affects children and young adults. 2-Methoxyestradiol (2-ME), a naturally occurring estrogen metabolite, kills osteosarcoma cells, but does not affect normal osteoblasts. In order to effectively target osteosarcoma and improve the therapeutic index of the drug 2-ME, we have encapsulated 2-ME in a composite of oligo-(polyethylene glycol) fumarate (OPF) hydrogel and poly (lactic-co-glycolic acid) (PLGA) microspheres and investigated the effect of polymer composition on 2-ME release kinetics and osteosarcoma cell survival. The in vitro study shows that 2-ME can be released in a controlled manner over 21-days. The initial burst releases observed on day 1 were 50% and 32% for OPF and OPF/PLGA composites, respectively. The extended release kinetics show that 100% of the encapsulated 2-ME is released by day 12 from OPF, whereas the OPF/PLGA composites showed a release of 85% on day 21. 2-ME released from the polymers was biologically active and blocked osteosarcoma cell proliferation in vitro. Also, comparison of 2-ME delivery in osteosarcoma cells in culture, shows that direct treatment has no effect after 3 days, whereas polymer-mediated delivery produces anti-tumor effects that could be sustained for 21 days. These findings show that the OPF and PLGA polymeric system may prove to be useful in controlled and sustained delivery of 2-ME and could be further explored in the treatment of osteosarcoma. Copyright © 2012 Wiley Periodicals, Inc.

  9. Microsphere erosion in outer hydrogel membranes creating macroscopic porosity to counter biofouling-induced sensor degradation.

    Science.gov (United States)

    Vaddiraju, S; Wang, Y; Qiang, L; Burgess, D J; Papadimitrakopoulos, F

    2012-10-16

    Biofouling and tissue inflammation present major challenges toward the realization of long-term implantable glucose sensors. Following sensor implantation, proteins and cells adsorb on sensor surfaces to not only inhibit glucose flux but also signal a cascade of inflammatory events that eventually lead to permeability-reducing fibrotic encapsulation. The use of drug-eluting hydrogels as outer sensor coatings has shown considerable promise to mitigate these problems via the localized delivery of tissue response modifiers to suppress inflammation and fibrosis, along with reducing protein and cell absorption. Biodegradable poly (lactic-co-glycolic) acid (PLGA) microspheres, encapsulated within a poly (vinyl alcohol) (PVA) hydrogel matrix, present a model coating where the localized delivery of the potent anti-inflammatory drug dexamethasone has been shown to suppress inflammation over a period of 1-3 months. Here, it is shown that the degradation of the PLGA microspheres provides an auxiliary venue to offset the negative effects of protein adsorption. This was realized by: (1) the creation of fresh porosity within the PVA hydrogel following microsphere degradation (which is sustained until the complete microsphere degradation) and (2) rigidification of the PVA hydrogel to prevent its complete collapse onto the newly created void space. Incubation of the coated sensors in phosphate buffered saline (PBS) led to a monotonic increase in glucose permeability (50%), with a corresponding enhancement in sensor sensitivity over a 1 month period. Incubation in serum resulted in biofouling and consequent clogging of the hydrogel microporosity. This, however, was partially offset by the generated macroscopic porosity following microsphere degradation. As a result of this, a 2-fold recovery in sensor sensitivity for devices with microsphere/hydrogel composite coatings was observed as opposed to similar devices with blank hydrogel coatings. These findings suggest that the use of

  10. Design of a formulation for the preparation of {sup 99m} Tc-(V)-Dmsa and {sup 186} Re-(V)-Dmsa; Diseno de una formulacion para la obtencion de {sup 99m} Tc-(V)-DMSA y {sup 186} Re-(V)-DMSA

    Energy Technology Data Exchange (ETDEWEB)

    Marquez L, M B [Universidad Autonoma del Estado de Mexico. Facultad de Quimica. Toluca (Mexico)

    1998-06-01

    Among the radiopharmaceuticals used for neoplasia, we can find the dimercaptosuccinic acid (Dmsa) labelled with {sup 99m} Tc and {sup 186/188} Re. Initially, the {sup 99m} Tc-(III)-Dmsa was employed as a renal image agent. Nevertheless, when it is prepared into a basic solution, the {sup 99m} Tc-(V)-Dmsa complex is produced in high yield being cumulated by cells with a great metabolic activity. This property makes it a useful radiopharmaceutical for the detection of medullary thyroid carcinoma (MTC), soft-tissue tumors and other head and neck tumors. On the other hand, the renewed interest in {beta} - emitting radionuclides, suggests that the {sup 186} Re-(V)-Dmsa complex could be used as antineoplastic agent in therapy. However, the techniques reported for the preparation of these compounds lack of stability studies and they are still in process of investigation, compromising to continue on the development of the radiopharmaceuticals by introducing new possibilities for better products already known, obtaining in this way, the approximation to the ideal radiopharmaceutical. The objective of this work is to design a freeze dried kit formulation for the instant preparation of {sup 99m} Tc-(V)-Dmsa and {sup 186} Re-(V)-Dmsa complexes useful in the diagnostic and therapy of soft-tissue tumors and other head and neck tumors. We obtained a freeze dried stable formulation for the preparation of {sup 99m} Tc-(V)-Dmsa kit with a radiochemical purity higher than 90 %, which fulfills with the quality control of radiopharmaceuticals. Furthermore, we developed analytical techniques for the determination of the different chemical compounds into the lyophilized kit. On the other hand, we obtained the optimum conditions for preparation of {sup 186} Re-(V)-Dmsa complex in high radiochemical yields (>90%). (Author).

  11. Importance of DMSA scintigraphy in children with the first urinary infection

    International Nuclear Information System (INIS)

    Petrovski, Z.P.

    2002-01-01

    The purpose of the study was to evaluate the role of Tc-99m DMSA scintigraphy in children with onset of symptoms of urinary tract infection (UTI). Diagnosis of UTI was confirmed with clinical and biological data and urinary culture.We observed 36 children(29 female and 4 male) without known previous UTI, aged between 1-8 years with average age of 3,7 yrs. DMSA images were obtained within 10 days of diagnosis. Focal cortical defects suggestive of renal scarring with reduction of DMSA uptake were found in 11(30,5%)patients, unilateral in 9 and bilateral in 2 children. Changes of DMSA scan were classified in three groups (A and B-with focal changes of different intensity, C-global contraction of kidney or shrinken kidney). Among the 14 children with clinical symptoms for acute pyelonephritis (APN),8(57%) pts showed abnormal DMSA scintigraphy findings, while 3(13,6%) pts of the 22 children considered as UTI also revealed pathology in DMSA scintigraphy. After treatment 6 months later, 11 abnormal scintigrams were repeated, from which 45,4%(5/11) did completely normalized, 27,3%(3/11) showed partial recovery and 27,3% (3/11) revealed constantly renal lesions in DMSA scan. As a conclusion, the first UTI in childhood is a well recognised cause of chronic renal scarring and renal failure in a small percentage of children. Tc-99m DMSA scintigraphy should be a routine examination in the first UTI with and without clinical findings of APN

  12. Optimizing renal DMSA-scintigraphy with 7-pinhole collimator

    International Nuclear Information System (INIS)

    Botsch, H.; Pottmeyer, A.; Savaser, A.; Lochner, B.; Felix, R.

    1982-01-01

    Multiple pinhole emission tomographic imaging techniques are currently being applied to imaging of organs of a limited size. The purpose of this study was to evaluate the feasibility of this technique in kidney imaging with Tcsup(99m)-DMSA. A 7-pinhole collimator having 4.5 mm. pinhole apertures was used in conjunction with a widefield camera. Left and right kidney were imaged separately. Twelve small renal cysts with a diameter of 1 to 3.5 cm. verified by US or CAT were investigated by 7-pinhole and planar scintigraphy. Eight of 12 renal cysts were identified by 7-pinhole scintigraphy whereas only one cyst was seen by planar scintigraphy. The borderline of cysts detection was 1.5 cm. in 7-pinhole tomography. Basing on these comparative studies and experiences on many patient investigations it seems reasonable to perform renal scintigraphy with 7-pinhole tomography in a routine manner. (orig.)

  13. Accuracy of early DMSA scan for VUR in young children with febrile UTI.

    Science.gov (United States)

    Zhang, Xin; Xu, Hong; Zhou, Lijun; Cao, Qi; Shen, Qian; Sun, Li; Fang, Xiaoyan; Guo, Wei; Zhai, Yihui; Rao, Jia; Pa, Mier; Zhao, Ruifang; Bi, Yunli

    2014-01-01

    To evaluate the accuracy of an acute (99m)Tc-dimercaptosuccinic acid (DMSA) scan in predicting dilating vesicoureteral reflux (VUR) among young children with a febrile urinary tract infection (UTI). The medical records of children (≤ 2 years of age), presenting with febrile UTI between January 2000 and December 2011, were retrospectively reviewed. A total of 523 children were included in this study, of whom 397 children (75.9%) had abnormal DMSA results and 178 children (34.0%) were identified as VUR on micturating cystourethrography (MCU). Among all the patients, the number of children with dilating VUR was 151 (28.9%). The rate of abnormal results on DMSA for the dilating VUR group was significantly higher than the rates for the non-VUR and low-grade VUR groups (P UTI, an acute DMSA scan is valuable in the exclusion of dilating VUR. The likelihood of the presence of dilating VUR on MCU is rather low when the result of DMSA is negative. DMSA should be conducted to assess the need for an MCU.

  14. Glass microspheres for brachytherapy

    International Nuclear Information System (INIS)

    Prado, Miguel O.; Prastalo, Simon; Blaumann, Herman; Longhino, Juan M.; Repetto Llamazares, A.H.V.

    2007-01-01

    We developed the capacity to produce glass microspheres containing in their structure one or more radioactive isotopes useful for brachytherapy. We studied the various facts related with their production: (Rare earth) alumino silicate glass making, glass characterization, microspheres production, nuclear activation through (n,γ) nuclear reactions, mechanical characterization before and after irradiation. Corrosion tests in simulated human plasma and mechanical properties characterization were done before and after irradiation. (author) [es

  15. Renal function study assessed by 99mTc-DMSA renal scintigraphy before and after PNL

    International Nuclear Information System (INIS)

    Sakurai, Masaki; Hioki, Takuichi; Okuno, Toshiyuki; Sugimura, Yoshiki; Yamakawa, Kensuke; Yanagawa, Makoto; Tajima, Kazuhiro; Tochigi, Hiromi; Kawamura, Juichi

    1990-01-01

    99m Tc-DMSA renal scintigraphy was carried out in 54 patients with unilateral renal stones before and after PNL. Four to 8 weeks after PNL the DMSA renal uptake significantly decreased to 17.2±6.0% from 18.2±6.7% before PNL. DMSA renal uptake did not change in the contralateral side. Since in some patients changes in the DMSA renal uptake of 5-7% were observed after PNL not only in the PNL side but also in the contralateral side, the renal function was assessed by the formula: DMSA renal uptake in the PNL side/DMSA renal uptake in the contralateral side, and the change of this ratio was evaluated in 44 patients, in whom the renal DMSA uptake in the PNL side was less than two times that in the contralateral side. The DMSA renal uptake ratio decreased to 95.6±8.7% from the base line 4-8 weeks after PNL. This change was statistically significant. Some functional risks such as massive bleeding with PNL, the fever after PNL and the number of nephrostomy tract did not affect the decrease in the renal function. In 29 patients in whom renal function was reevaluated one year after PNL, the DMSA renal uptake ratio significantly decreased to 94.2±9.6% from the base line 4-8 weeks after PNL. But the ratio significantly improved to 99.6±11.6% about one year after PNL. In two patients with a cold area on the renal image, the renal function of the operated side still remained at about 80% levels from the base line even one year after PNL. It is concluded that although renal function slightly decreased 4-8 weeks after PNL, it is expected to improve within one year after PNL. But in the case with a cold area on the renal image, the complete functional recovery would not be expected. 99m Tc-DMSA renal scintigraphy is a useful adjunct to evaluate the renal function before and after PNL. (author)

  16. Method for sizing hollow microspheres

    Science.gov (United States)

    Farnum, E.H.; Fries, R.J.

    1975-10-29

    Hollow Microspheres may be effectively sized by placing them beneath a screen stack completely immersed in an ultrasonic bath containing a liquid having a density at which the microspheres float and ultrasonically agitating the bath.

  17. Development of methods of labeling pentavalent DMSA with 99mTc and 188Re

    International Nuclear Information System (INIS)

    Brambilla, Tania de Paula

    2009-01-01

    Technetium-99 m is the most useful radionuclide in diagnostic imaging procedures in Nuclear Medicine, more than 80 percent of radiopharmaceuticals are 99m Tc-labeled compounds. 99m Tc-DMSA(V) has been used for imaging of soft tissue, head and neck tumors. It shows a particularly high specificity for medullary thyroid carcinoma and bone metastases in a variety of cancers. Biodistribution studies of 188 Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of 99m Tc-DMSA(V), so this agent could be used for targeted radiotherapy of these tumors. The aim of this work is the development of methods of labeling DMSA(V) with 99m Tc and 188 Re. 99m Tc-DMSA(V) can be prepared by two methods. One of them is the indirect one, through the use of a commercial kit of DMSA (III), by adjusting the pH from 2.5 to ∼ 8.5 with NaHCO 3 . This method was evaluated and optimized presenting high labeling yields. The other method is the direct one, through the preparation of a lyophilised kit ready for labeling with 99m Tc, being the method of interest of this work, due to the easy of its clinical use. The most adequate formulation of the kit was: 1.71 mg of DMSA, 0.53 mg of SnCl 2 .2H 2 O and 0.83 mg of ascorbic acid (pH 9). Labeling yields higher than 95% were achieved labeling this kit with 1 to 2 m L of 99m Tc with activities up to 4736 MBq (128 mCi). The kit was stable up to 6 months and biodistribution studies confirmed the quality of the DMSA (V) labeled with 99m Tc using this kit. The reduction potential of Re is lower than the one for Tc, so the labeling conditions of 188 Re-DMSA(V) are different from the ones used for 99m Tc- DMSA(V). 188 Re-DMSA(V) is prepared in acid solution, that makes it possible to use the DMSA (III) commercial kit developed for labeling with 99m Tc, prepared in pH 2.5, for labeling with 188 Re. Labeling yields higher than 95% were achieved with this methodology, with a rection time of 30 minutes at 100 deg C using no more

  18. Study of {sup 99m}Tc-DMSA biodistribution in experimental animals

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Thais O.M. de; Silva, Natanael G. da; Colturato, Maria T.; Felgueiras, Carlos F.; Mengatti, Jair; Fukumori, Neuza T.O.; Matsuda, Margareth M.N.; Araújo, Elaine B. de, E-mail: thais.castrom@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia

    2017-11-01

    {sup 99m}Tc-DMSA, succimer ({sup 99m}Tc), is a radiopharmaceutical commonly used in nuclear medicine for renal function evaluation by imaging. In order to achieve adequate labeling of the product with good radiochemical yield and standardized biological distribution, the interval of 185 - 3700 MBq should be kept in a maximum volume of 3 mL for product labeling. Moreover, one should avoid exposing the reconstituted solution to oxygen and using the product after four hours post labeling. The aim of the study was to quantify and evaluate the influence of different DMSA complexes on biological distribution of the radiopharmaceutical in experimental animals, taking in account variations in the labeling parameters. Radiochemical purity was determined by paper and thin layer chromatography using both acetone/Whatman 3MM, 0.9% NaCl/TLC-SG and n-propanol/ H{sub 2}O/acetic acid (4:3:1 V/V/V)/TLC-SG systems respectively for quantification of {sup 99m}TcO{sub 4} - and {sup 99m}TcO{sub 2} plus some {sup 99m}Tc-DMSA complexes. The labeling activity did not significantly affect the extent of the main complex generation. The presence of oxygen and the concentration of {sup 99}Tc did not markedly change the percentage of the radiochemical impurities in the preparation. Radiochemical purity tests of the DMSA-{sup 99m}Tc based on IPEN-CNEN DMSA-TEC reagent and on another producer's reagent showed similar results. Although the routine method used by IPEN-CNEN to determine the radiochemical yield of {sup 99m}Tc-DMSA was not able to discriminate among {sup 99m}Tc-DMSA complexes, the renal uptake and the kidney to liver plus spleen uptake ratio in rats met the official compendia criteria for the radiopharmaceutical. (author)

  19. Optimization of labelling procedure of 188rE-DMSA(v)

    International Nuclear Information System (INIS)

    Dantas, Danielle M.; Brambilla, Tania P.; Reis, Nicoli F.; Osso Junior, Joao A.

    2011-01-01

    Radionuclide therapy (RNT) is emerging as an important tool of nuclear medicine. Apart from the well established 131 I, several other promising radionuclides have been identified, among them 188 Re, 90 Y and 177 Lu. 188 Re has received a lot of attention in the past decade, due to its favourable nuclear characteristics [t 1/2 16.9 h, E b eta m ax 2.12 MeV and E g amma 155 keV (15%) suitable for imaging, including the fact that it is carrier-free and can be obtained cost-effectively through the generator 188 W- 188 Re. Biodistribution studies of 188 Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of 99m Tc-DMSA(V), so this agent could be used for targeted radiotherapy of medullary thyroid carcinoma, bone metastases, soft tissue and others tumors. The aim of this work is to evaluate two labeling procedures for the preparation of 188 Re-DMSA(V). The first method was prepared using a commercial kit of DMSA(III) for labeling with 99m Tc at high temperature (100 deg C). The second method was prepared in a vial containing 2.5 mg of DMSA, 1.00 mg of SnCl 2 .2H 2 O and 10 mg of sodium oxalate, 10 mg of cyclodextrin, in a total volume of 2.0 mL. The pH was adjusted to 3 with 37% HCl. After labeling the solution was stirred and incubated for 30 min at room temperature. The radiochemical purity was determined using TLC-SG developed with two different solvent systems: Acetone and glycine. Preliminary results for both methods of labeling 188 Re-DMSA(V) showed that the labeling yield was >95%. Further experiments are also necessary to optimize the labeling methodology of 188 Re-DMSA(V).author)

  20. Pentavalent 99Tcm - DMSA SPECT in primary brain tumours of glial cell origin

    International Nuclear Information System (INIS)

    Chung, D.K.; Evans, S.G.; Larcos, G.; Gruenewald, S.; Kumar, V.; Barton, M.

    1999-01-01

    Full text: 99 Tc m (V)-DMSA [DMSA(V)] has shown promise in brain tumour imaging. This study aimed to assess the role of DMSA(V) brain SPET in glioma for: (1) predicting the histopathological grade of malignancy, (2) monitoring response to therapy and (3) discriminating recurrent tumour from post-radiotherapy necrosis. Twenty-three patients (pts) (14 men, 9 women) of mean age 57 years (range 20-79) were referred with a lesion on CT/MRI (14 new presentations, 5 known and 4 suspected tumour recurrence). Up to 555 MBq of 99 Tc m (V)DMSA were administered and SPET was acquired at 3 h. Tumour uptake ratio (UR) was calculated by the ratio of activity in the tumour to a region in the contralateral brain. All 19 pts with known tumour showed DMSA(V) uptake. The 14 pts with new tumours (10 grade IV, I grade III, 2 grade II and 1 necrotic tumour) had a pre-therapy mean UR of 7.7 (range 2.8-13.6). The 3 lower-grade tumours were scattered widely within this range. Four pts completed radiotherapy and returned for a post-therapy scan, where the UR was less than the pre-therapy UR in 2, unchanged in 1 and greater in 1. The 5 known recurrent tumours had a mean UR of 13.5 (range 7.3-24.9). In the 4 pts with suspected recurrence, the DMSA(V) scan result agreed with clinical course or PET in 3 but was falsely positive in 1. In summary, 99 Tc m (V)-DMSA: (1) showed uptake in all known glial cell tumours in this series, however the UR did not correlate with the histopathological grade; (2) may be useful for discriminating tumour recurrence from post-radiotherapy necrosis; and (3) may have a role in predicting post-therapy prognosis

  1. Study of "9"9"mTc-DMSA biodistribution in experimental animals

    International Nuclear Information System (INIS)

    Castro, Thais O.M. de; Silva, Natanael G. da; Colturato, Maria T.; Felgueiras, Carlos F.; Mengatti, Jair; Fukumori, Neuza T.O.; Matsuda, Margareth M.N.; Araújo, Elaine B. de

    2017-01-01

    "9"9"mTc-DMSA, succimer ("9"9"mTc), is a radiopharmaceutical commonly used in nuclear medicine for renal function evaluation by imaging. In order to achieve adequate labeling of the product with good radiochemical yield and standardized biological distribution, the interval of 185 - 3700 MBq should be kept in a maximum volume of 3 mL for product labeling. Moreover, one should avoid exposing the reconstituted solution to oxygen and using the product after four hours post labeling. The aim of the study was to quantify and evaluate the influence of different DMSA complexes on biological distribution of the radiopharmaceutical in experimental animals, taking in account variations in the labeling parameters. Radiochemical purity was determined by paper and thin layer chromatography using both acetone/Whatman 3MM, 0.9% NaCl/TLC-SG and n-propanol/ H_2O/acetic acid (4:3:1 V/V/V)/TLC-SG systems respectively for quantification of "9"9"mTcO_4 - and "9"9"mTcO_2 plus some "9"9"mTc-DMSA complexes. The labeling activity did not significantly affect the extent of the main complex generation. The presence of oxygen and the concentration of "9"9Tc did not markedly change the percentage of the radiochemical impurities in the preparation. Radiochemical purity tests of the DMSA-"9"9"mTc based on IPEN-CNEN DMSA-TEC reagent and on another producer's reagent showed similar results. Although the routine method used by IPEN-CNEN to determine the radiochemical yield of "9"9"mTc-DMSA was not able to discriminate among "9"9"mTc-DMSA complexes, the renal uptake and the kidney to liver plus spleen uptake ratio in rats met the official compendia criteria for the radiopharmaceutical. (author)

  2. Recurrent urinary tract infections in young children: role of DMSA scintigraphy in detecting vesicoureteric reflux

    International Nuclear Information System (INIS)

    Awais, Muhammad; Rehman, Abdul; Nadeem, Naila; Zaman, Maseeh Uz

    2015-01-01

    Performing micturiting cystourethrography (MCUG) in young children with recurrent urinary tract infections is controversial with discrepancy among the major guidelines. Previous studies have shown that a normal dimercaptosuccinic acid (DMSA) scintigraphy may avoid the need of performing MCUG for detecting vesicoureteric reflux in children with first febrile urinary tract infection. However, the role of DMSA for ruling out vesicoureteric reflux in children with recurrent urinary tract infections has not been studied. Approval from institutional ethical review committee was sought and the requirement of informed consent was waived. A total of 50 children under the age of 10 years with recurrent urinary tract infections underwent MCUG scan within 3 months of DMSA scan from January 2011 to September 2012 at our institution. Diagnosis of recurrent urinary tract infections and grading of vesicoureteric reflux was according to previously established standards. Abnormalities on DMSA scan - scarring, hydronephrosis and reduced differential renal function - were compared with presence of vesicoureteric reflux on MCUG. High-grade vesicoureteric reflux was noted on MCUG in 22 (44%) cases. The findings on DMSA included hydronephrosis and scarring in 25 (50%) and 25 (50%) cases, respectively. Abnormalities on DMSA scan for detecting the presence of high-grade vesicoureteric reflux on MCUG examination had sensitivity, specificity, positive and negative predictive values of 95.45%, 35.71%, 53.85% and 90.91%, respectively. The positive and negative likelihood ratios were 1.48 and 0.13 respectively. DMSA scan had high overall sensitivity and negative predictive value with a low negative likelihood ratio for ruling out high-grade vesicoureteric reflux on MCUG, which may obviate the need of invasive MCUG along with its associated drawbacks. (orig.)

  3. Recurrent urinary tract infections in young children: role of DMSA scintigraphy in detecting vesicoureteric reflux

    Energy Technology Data Exchange (ETDEWEB)

    Awais, Muhammad; Rehman, Abdul; Nadeem, Naila [Aga Khan University Hospital, Department of Radiology, Karachi (Pakistan); Zaman, Maseeh Uz [Aga Khan University Hospital, Nuclear Medicine, Department of Radiology, Karachi (Pakistan)

    2014-07-04

    Performing micturiting cystourethrography (MCUG) in young children with recurrent urinary tract infections is controversial with discrepancy among the major guidelines. Previous studies have shown that a normal dimercaptosuccinic acid (DMSA) scintigraphy may avoid the need of performing MCUG for detecting vesicoureteric reflux in children with first febrile urinary tract infection. However, the role of DMSA for ruling out vesicoureteric reflux in children with recurrent urinary tract infections has not been studied. Approval from institutional ethical review committee was sought and the requirement of informed consent was waived. A total of 50 children under the age of 10 years with recurrent urinary tract infections underwent MCUG scan within 3 months of DMSA scan from January 2011 to September 2012 at our institution. Diagnosis of recurrent urinary tract infections and grading of vesicoureteric reflux was according to previously established standards. Abnormalities on DMSA scan - scarring, hydronephrosis and reduced differential renal function - were compared with presence of vesicoureteric reflux on MCUG. High-grade vesicoureteric reflux was noted on MCUG in 22 (44%) cases. The findings on DMSA included hydronephrosis and scarring in 25 (50%) and 25 (50%) cases, respectively. Abnormalities on DMSA scan for detecting the presence of high-grade vesicoureteric reflux on MCUG examination had sensitivity, specificity, positive and negative predictive values of 95.45%, 35.71%, 53.85% and 90.91%, respectively. The positive and negative likelihood ratios were 1.48 and 0.13 respectively. DMSA scan had high overall sensitivity and negative predictive value with a low negative likelihood ratio for ruling out high-grade vesicoureteric reflux on MCUG, which may obviate the need of invasive MCUG along with its associated drawbacks. (orig.)

  4. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2011-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  5. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2010-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  6. Ceramic microspheres for cementing applications

    NARCIS (Netherlands)

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  7. Labeling mesenchymal cells with DMSA-coated gold and iron oxide nanoparticles: assessment of biocompatibility and potential applications.

    Science.gov (United States)

    Silva, Luisa H A; da Silva, Jaqueline R; Ferreira, Guilherme A; Silva, Renata C; Lima, Emilia C D; Azevedo, Ricardo B; Oliveira, Daniela M

    2016-07-18

    Nanoparticles' unique features have been highly explored in cellular therapies. However, nanoparticles can be cytotoxic. The cytotoxicity can be overcome by coating the nanoparticles with an appropriated surface modification. Nanoparticle coating influences biocompatibility between nanoparticles and cells and may affect some cell properties. Here, we evaluated the biocompatibility of gold and maghemite nanoparticles functionalized with 2,3-dimercaptosuccinic acid (DMSA), Au-DMSA and γ-Fe2O3-DMSA respectively, with human mesenchymal stem cells. Also, we tested these nanoparticles as tracers for mesenchymal stem cells in vivo tracking by computed tomography and as agents for mesenchymal stem cells magnetic targeting. Significant cell death was not observed in MTT, Trypan Blue and light microscopy analyses. However, ultra-structural alterations as swollen and degenerated mitochondria, high amounts of myelin figures and structures similar to apoptotic bodies were detected in some mesenchymal stem cells. Au-DMSA and γ-Fe2O3-DMSA labeling did not affect mesenchymal stem cells adipogenesis and osteogenesis differentiation, proliferation rates or lymphocyte suppression capability. The uptake measurements indicated that both inorganic nanoparticles were well uptaken by mesenchymal stem cells. However, Au-DMSA could not be detected in microtomograph after being incorporated by mesenchymal stem cells. γ-Fe2O3-DMSA labeled cells were magnetically responsive in vitro and after infused in vivo in an experimental model of lung silicosis. In terms of biocompatibility, the use of γ-Fe2O3-DMSA and Au-DMSA as tracers for mesenchymal stem cells was assured. However, Au-DMSA shown to be not suitable for visualization and tracking of these cells in vivo by standard computed microtomography. Otherwise, γ-Fe2O3-DMSA shows to be a promising agent for mesenchymal stem cells magnetic targeting.

  8. Repair of rat cranial bone defect by using bone morphogenetic protein-2-related peptide combined with microspheres composed of polylactic acid/polyglycolic acid copolymer and chitosan

    International Nuclear Information System (INIS)

    Li, Jingfeng; Jin, Lin; Zhu, Shaobo; Wang, Mingbo; Xu, Shuyun

    2015-01-01

    The effects of the transplanted bone morphogenetic protein-2 (BMP2) -related peptide P24 and rhBMP 2 combined with poly(lactic-co-glycolic acid) (PLGA)/chitosan (CS) microspheres were investigated in promoting the repair of rat cranial bone defect. Forty white rats were selected and equally divided into four groups (group A: 1 μg of rhBMP 2 /PLGA/CS composite; group B: 3 mg of P24/PLGA/CS composite; group C: 0.5 μg of rhBMP 2 + 1.5 mg of P24/PLGA/CS composite; group D: blank PLGA/CS material), and rat cranial bone defect models with a diameter of 5 mm were established. The materials were transplanted to the cranial bone defects. The animals were sacrificed on weeks 6 and 12 post-operation. Radiographic examinations (x-ray imaging and 3D CT scanning) and histological evaluations were performed. The repaired areas of cranial bone defects were measured, and the osteogenetic abilities of various materials were compared. Cranial histology, imaging, and repaired area measurements showed that the osteogenetic effects at two time points (weeks 6 and 12) in group C were better than those in groups A and B. The effects in groups A and B were similar. Group D achieved the worst repair effect of cranial bone defects, where a large number of fibrous connective tissues were observed. The PLGA/CS composite microspheres loaded with rhBMP 2 and P24 had optimal concrescence and could mutually increase their osteogenesis capability. rhBMP 2 + P24/PLGA/CS composite is a novel material for bone defect repair with stable activity to induce bone formation. (paper)

  9. Preparation of alumina microspheres

    International Nuclear Information System (INIS)

    Santos, W.R. dos; Abrao, A.

    1980-01-01

    Inorganic exchangers are widely used for adsorption and column partition chromatography. The main difficulty of using commercial alumina (in powder) for column chromatography is related to its packing, and the operations through the column become diffcult and time-consuming; also it turns to be virtually impossible to use large dimension columns. In order to eliminate these problems, a process for the preparation of alumina micro-spheres was developed as an adaptation of a similar process used to prepare nuclear fuel microspheres (UO 2 , ThO 2 ). The flowsheet of this process is presented together with the analytical results of sphericity after calcination, granulometry, density and characterization by X-ray diffractometry. Solubility tests showed that the so-prepared microspheres are well resistant to strong acids and bases; retention tests showed their efficiency, mainly to copper. (C.L.B.) [pt

  10. Evaluation of pentavalent Tc-99m DMSA scintigraphy in small cell and nonsmall cell lung cancers

    Energy Technology Data Exchange (ETDEWEB)

    Atasever, T.; Guendogdu, C.; Vural, G.; Kapucu, L.Oe.; Karalezli, A.; Uenlue, M. [Gazi Univ., Faculty of Medicine, Nuclear Medicine Department and Atatuerk Chest Diseases and Surgery Center, Ankara (Turkey)

    1997-10-01

    Aim: The purpose of this study was to evaluate the clinical usefulness of Tc-99m (V) DMSA in patients suspected of lung cancer and determine whether this agent may have value in differentiation between small cell (SCLC) and non-small cell (NSCLC) lung carcinoma. Methods: Thirty-six patients with clinical and radiological suspicion of primary lung carcinoma were injected 450-600 MBq of Tc-99m (V) DMSA intravenously. Whole body and planar anterior, posterior thorax images were obtained 4-5 h after injection of the radioactive complex. Results: Histopathological results confirmed 23 NSCLC, 10 SCLC and 1 metastatic lung carcinoma and 2 lung abscess. Nineteen of the 23 (82%) NSCLC and all of the 10 (100%) SCLC cases showed Tc-99m (V) DMSA uptake. Single metastatic lung cancer also accumulated radiotracer. Lung abscess did not show uptake. Lesion/Nonlesion (L/N) ratio of SCLC (1.59{+-}0.32) and NSCLC (1.43{+-}0.19) tumour types did not show statistical difference (p>0.05). Tc-99m (V) DMSA whole body imaging also showed bone metastases. Conclusion: Tc-99m (V) DMSA is a noninvasive and cheap imaging method to detect malignant lung cancers and their bone metastases but, differentiation of SCLC and NSCLC is not possible. (orig.) [Deutsch] Ziel: Pruefung der klinischen Brauchbarkeit von {sup 99m}Tc-(V) DMSA bei Patienten mit Verdacht auf Bronchialkarzinom im Hinblick auf die Moeglichkeit einer Differenzierung zwischen Kleinzeller (KLZ) und Nichtkleinzeller (NKLZ). Methoden: Bei 36 Patienten mit klinischem und radiologischem Hinweis auf Bronchialkarzinom wurden 450 bis 600 MBq {sup 99m}Tc-(V) DMSA i.v. appliziert. 4-5 h spaeter wurden Ganzkoerper- und planare Szintigramme des Thorax durchgefuehrt. Ergebnisse: Feingewebliche Untersuchungen bestaetigten in 23 Faellen NKLZ, zehnmal KLZ, einmal ein metastasierendes Bronchialkarzinom und zwei Lungenabszesse. 19 der 23 NKLZ- (82%) und 100% der KLZ-Faelle zeigten eine {sup 99m}Tc-(V) DMSA-Speicherung ebenso wie das metastasierende

  11. Variability in DMSA reporting following urinary tract infection in children: pinhole, planar, and pinhole with planar

    International Nuclear Information System (INIS)

    Rossleigh, M.A.; Christian, C.L.; Craig, J.C.; Howman-Giles, R.B.; Grunewald, S.

    2004-01-01

    Purpose: To determine whether the provision of DMSA images obtained by pinhole collimation reduces inter-observer variability of reporting compared with planar DMSA images alone. Methods: One hundred consecutive DMSA images were independently interpreted three times (pinhole alone, planar alone, pinhole and planar) by four participating nuclear medicine specialists from different departments and in random order. The presence or absence of renal parenchymal abnormality was classified using the modified four level grading system of Goldraich with mean values for the 6 comparisons reported. Results: The proportion of DMSA images interpreted as abnormal was 31% for planar, 34% for pinhole and 33% for planar with pinhole. Agreement was 89% for planar alone, 89% for pinhole alone and 90% for planar with pinhole, with kappa values 0.74, 0.75 and 0.80 respectively for the normal-abnormal scan classification of individual children. These results did not vary appreciably whether interpretation of patients, kidneys or kidney zones was compared. Reasons for disagreement in reporting included different interpretations of 'abnormalities' as normal anatomical variations (splenic impression, fetal lobulation, duplex collecting systems, column of Bertin) or true parenchymal abnormalities, different adjustments in thresholds for reporting abnormality when images were technically suboptimal, different weighting given to pinhole and planar images when both were provided, and error. Conclusion: Four experienced nuclear medicine physicians showed substantial agreement in the interpretation of planar alone, pinhole alone and planar with pinhole DMSA images, but the provision of both sets of images, planar and pinhole, did not reduce variability. (authors)

  12. Synthesis of {sup 188}Re-DMSA complex using carrier-free {sup 188}Re

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Kazuyuki; Izumo, Mishiroku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Islam, M S

    1997-03-01

    The synthesis of rhenium-DMSA labelled compound using carrier-free {sup 188}Re from the {sup 188}W/{sup 188}Re generator has been carried out. Stannous chloride was used as the reducing agent for reduction of rhenium and ascorbic acid was used as an antioxidant in the reaction media. The dependence of the yield of Re-DMSA complex upon the concentration of reducing agent, pH, reaction time, anti-oxidant, carrier and temperature was investigated. Under optimum conditions, the yield of Re-DMSA complexes were more than 98% for the carrier-free as well as carrier-added {sup 188}Re. The stability of the Re-DMSA complexes at different pH and time were also investigated. It was found that the Re-DMSA complex was very stable and did not undergo any changes or decomposition with the changes of pH from its initial values even after 48 hours of pH change for carrier-free as well as carrier-added complexes. (author)

  13. Evaluation of pentavalent Tc-99m DMSA scintigraphy in small cell and nonsmall cell lung cancers

    International Nuclear Information System (INIS)

    Atasever, T.; Guendogdu, C.; Vural, G.; Kapucu, L.Oe.; Karalezli, A.; Uenlue, M.

    1997-01-01

    Aim: The purpose of this study was to evaluate the clinical usefulness of Tc-99m (V) DMSA in patients suspected of lung cancer and determine whether this agent may have value in differentiation between small cell (SCLC) and non-small cell (NSCLC) lung carcinoma. Methods: Thirty-six patients with clinical and radiological suspicion of primary lung carcinoma were injected 450-600 MBq of Tc-99m (V) DMSA intravenously. Whole body and planar anterior, posterior thorax images were obtained 4-5 h after injection of the radioactive complex. Results: Histopathological results confirmed 23 NSCLC, 10 SCLC and 1 metastatic lung carcinoma and 2 lung abscess. Nineteen of the 23 (82%) NSCLC and all of the 10 (100%) SCLC cases showed Tc-99m (V) DMSA uptake. Single metastatic lung cancer also accumulated radiotracer. Lung abscess did not show uptake. Lesion/Nonlesion (L/N) ratio of SCLC (1.59±0.32) and NSCLC (1.43±0.19) tumour types did not show statistical difference (p>0.05). Tc-99m (V) DMSA whole body imaging also showed bone metastases. Conclusion: Tc-99m (V) DMSA is a noninvasive and cheap imaging method to detect malignant lung cancers and their bone metastases but, differentiation of SCLC and NSCLC is not possible. (orig.) [de

  14. Renal handling of technetium-99m DMSA in rats with proximal tubular dysfunction

    International Nuclear Information System (INIS)

    Provoost, A.P.; Van Aken, M.

    1985-01-01

    The renal handling of technetium-/sup 99m/ dimercaptosuccinic acid ([/sup 99m/Tc]DMSA) was studied in rats before and after treatment with Na-maleate (2 mmol/kg i.v.). In the control period, when measured 2 hr after the intravenous injection of [/sup 99m/Tc]DMSA, 39.9% of the injected dose was in the kidneys and 14.6% was in the bladder. After Na-maleate treatment, only 6.4% of the injected dose of [/sup 99m/Tc]DMSA was retained in the kidneys while 37.9% was found in the bladder. Subsequent studies revealed that Na-maleate produced a fall in the glomerular filtration rate, the effective renal plasma flow, and a generalized proximal tubular dysfunction. The latter was characterized by polyuria and an increased excretion of glucose, protein, albumin, calcium, and inorganic phosphate. It was concluded that proximal tubular dysfunction markedly alters the renal handling of [/sup 99m/Tc]DMSA. Whether this augmented urinary excretion is due to an inhibition of reabsorption or an enhanced cellular efflux of [/sup 99m/Tc]DMSA remains to be answered

  15. Childhood acute pyelonephritis: comparison of power Doppler sonography and Tc-DMSA scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Stogianni, Aggeliki; Oikonomou, Ippoliti; Dimitriadis, Athanasios [Aristotle University of Thessaloniki, Department of Radiology, AHEPA Hospital, Thessaloniki (Greece); Nikolopoulos, Panagiotis [424 Army Hospital, Department of Radiology, Thessaloniki (Greece); Gatzola, Magdalini [Aristotle University of Thessaloniki, 2nd Paediatric Clinic, AHEPA Hospital, Thessaloniki (Greece); Balaris, Vassilios [Aristotle University of Thessaloniki, Department of Nuclear Medicine, AHEPA Hospital, Thessaloniki (Greece); Farmakiotis, Dimitrios [Infectious Diseases Hospital of Thessaloniki, Department of Medicine, Thessaloniki (Greece)

    2007-07-15

    Tc 99m DMSA scintigraphy is regarded as the gold standard for the detection and localization of acute pyelonephritis (APN) in children. Power Doppler sonography (PD US) is a radiation-free and cost-effective technique that could be useful in the diagnosis of APN in children. To compare the predictive value of PD US with DMSA scintigraphy in the diagnosis of APN in children. A total of 74 neonates and children with clinical findings consistent with possible upper urinary tract infection were evaluated with PD US and DMSA scintigraphy. Children with anatomic (grey-scale) abnormalities were excluded. A total of 147 kidneys were examined within the first 48 h after the onset of symptoms. Each kidney was divided into three zones (upper, middle, and lower third). APN was diagnosed by PD US in 46 kidneys. Sensitivity and specificity for detecting APN using DMSA scintigraphy as the reference standard were 73.8% and 85.7%, respectively. There was good agreement between PD US and DMSA scintigraphy in the localization of lesions. In clinically suspected APN, PD US has acceptable specificity and sensitivity, if performed within the first 48 h and could be helpful in neonates and children under 3 months of age in whom the use of scintigraphy is generally discouraged. (orig.)

  16. Is Ureter Visualization Possible on Tc-99m DMSA Scintigraphy with Vesicoureteral Reflux Patients?

    Directory of Open Access Journals (Sweden)

    Hasan Atilgan

    2014-12-01

    Full Text Available Aim: Ureter or pelvicalyceal system is not be vizualized with 99mTechnetium- dimercaptosuccinic acid (99mTc-DMSA which is accumulated by renal cortex normally. In this study the cases whose ureters are visible were reviewed with 99mTc-DMSA scintigraphy. Material and Method: 18 patients (5 females, 13 males with median age 3.5 years (min 2 months-max 18 years were included in this study. Twenty ureters and/or pelvis of 18 patients were visible in 99mTc-DMSA scintigraphy. In two patients%u2019s both ureters were visible. Vesicoureteral reflux (VUR grade, 99mTc-DMSA uptake, renal size, status of pelvicalyceal system, urea, creatinine levels were evaluated in all patients. Results: Three of the visible ureters were actually due to pelvicaliectasis. These pelvicaliectasic patients were excluded from the study. In the evaluation of the remaining 17 ureters of patients, congenital megaureter was present in three patients. Grade 3 VUR was detected in three patients, grade 4 was in three patients. VUR is seen as grade five in eight kidneys of seven patients because one of these patients has bilateral vizualized ureter. Discussion: In patients with congenital megaureter and VUR, ureters can be visible with 99mTc-DMSA scintigraphy and further imaging modalities are recommended for these patients.

  17. Silicon Microspheres Photonics

    International Nuclear Information System (INIS)

    Serpenguzel, A.

    2008-01-01

    Electrophotonic integrated circuits (EPICs), or alternatively, optoelectronic integrated circuit (OEICs) are the natural evolution of the microelectronic integrated circuit (IC) with the addition of photonic capabilities. Traditionally, the IC industry has been based on group IV silicon, whereas the photonics industry on group III-V semiconductors. However, silicon based photonic microdevices have been making strands in siliconizing photonics. Silicon microspheres with their high quality factor whispering gallery modes (WGMs), are ideal candidates for wavelength division multiplexing (WDM) applications in the standard near-infrared communication bands. In this work, we will discuss the possibility of using silicon microspheres for photonics applications in the near-infrared

  18. The value of filtered planar images in pediatric DMSA scans

    International Nuclear Information System (INIS)

    Mohammed, A.M.; Naddaf, S.Y.; Elgazzar, A.H.; Al-Abdul Salam, A.A.; Omar, A.A.

    2006-01-01

    The study was designed to demonstrate the value of filtered planar images in paediatric DMSA scanning. One hundred and seventy three patients ranged in age from 15 days to 12 years (mean: 4.3 years) with urinary tract infection (UTI) and clinical and/or laboratory suspicion of acute pyelonephritis (APN) were retrospectively studied. Planar images were filtered using Butterworth filter. The scan findings were reported as positive, negative or equivocal for cortical defects. Each scan was read in a double-blind fashion by two nuclear medicine physicians to evaluate inter-observer variations. Each kidney was divided into three zones, upper, middle and lower, and each zone was graded as positive, negative or equivocal for the presence of renal defects. Renal cortical defects were found in 66 patients (91 kidneys and 186 zones) with filtered images, 58 patients (81 kidneys and 175 zones) with planar images, and 69 patients (87 kidneys and 180 zones) with SPECT images. McNemar's test revealed statistically significant difference between filtered and planar images (p=0.038 for patients, 0.021 for kidneys and 0.034 for number of zones). Inter-observer agreement was 0.877 for filtered images, 0.915 for planar images and 0.915 for SPECT images. It was concluded that filtered planar images of renal cortex are comparable to SPECT images and can be used effectively in place of SPECT, when required, to shorten imaging time and eliminate motion artifacts, especially in the paediatric population. (author)

  19. Acute pyelonephritis in pediatric age: comparative study between power Doppler ultrasound scan and DMSA; Pielonefritis aguda en la edad pediatrica: estudio comparative entre la ecografiapower-Doppler y el DMSA

    Energy Technology Data Exchange (ETDEWEB)

    Muro, M. D.; Sanguesa, C.; Otero, M. C.; Piqueras, A. I.; Lloret, M. T. [Hospital Infantil Universitario La Fe. Valencia (Spain)

    2002-07-01

    To evaluate the usefulness of power Doppler (PD) Ultrasound Scan in the study of acute pyelonephritis (APN). To compare ultrasound scan results with those obtained with renal gammagraphy (DMSA). To relate the findings to the clinical criteria and to determine the presence of vesicoureteral reflux (VUR) in the serial micturition cystography (SMC). Prospective study of 92 patients (ages between 1 month and 10 years) with suspected clinical PNA. All children were initially subjected to PD ultrasound scan and DMSA. Those under 3 years old were also subjected to SMC for the study of VUR. PNA in the PD ultrasound scan was manifested by decrease in vascularisation and in the DMSA by decrease in caption in the affected zones. 87 renal units (RU) with PNA foci were detected. Conformity between the PD ultrasound scan and DMSA was 157 RU (92%): 52 positives, 22 negatives with PNA and 83 normal RU. The sensitivities of PD and DMSA were 65.5% and 69.0%. 51 SMC were performed, with VUR being detected in 18 (13 bilateral and 5 unilateral), in which the sensitivities of PD and DMSA were 65.5% and 69.0%. 51 SMC were performed, with VUR being detected in 18 (13 bilateral and 5 unilateral), in which the sensitivities of PD and DMSA were 80% and 85%, respectively. Mode B ultrasound scan and PD can replace DMSA in the initial study of PPNA. It is non-invasive, simple, economical and just as reliable as DMSA in expert hands. it can also postpone by up to 6 months the need to perform DMSA for detection of permanent renal damage. (Author) 22 refs.

  20. IVIVC from Long Acting Olanzapine Microspheres

    Directory of Open Access Journals (Sweden)

    Susan D'Souza

    2014-01-01

    Full Text Available In this study, four PLGA microsphere formulations of Olanzapine were characterized on the basis of their in vitro behavior at 37°C, using a dialysis based method, with the goal of obtaining an IVIVC. In vivo profiles were determined by deconvolution (Nelson-Wagner method and using fractional AUC. The in vitro and in vivo release profiles exhibited the same rank order of drug release. Further, in vivo profiles obtained with both approaches were nearly superimposable, suggesting that fractional AUC could be used as an alternative to the Nelson-Wagner method. A comparison of drug release profiles for the four formulations revealed that the in vitro profile lagged slightly behind in vivo release, but the results were not statistically significant (P0.96 between in vitro release and in vivo measurements confirmed the excellent relationship between in vitro drug release and the amount of drug absorbed in vivo. The results of this study suggest that proper selection of an in vitro method will greatly aid in establishing a Level A IVIVC for long acting injectables.

  1. Docetaxel-loaded PLGA and PLGA-PEG nanoparticles for intravenous application: pharmacokinetics and biodistribution profile.

    Science.gov (United States)

    Rafiei, Pedram; Haddadi, Azita

    2017-01-01

    Docetaxel is a highly potent anticancer agent being used in a wide spectrum of cancer types. There are important matters of concern regarding the drug's pharmacokinetics related to the conventional formulation. Poly(lactide- co -glycolide) (PLGA) is a biocompatible/biodegradable polymer with variable physicochemical characteristics, and its application in human has been approved by the United States Food and Drug Administration. PLGA gives polymeric nanoparticles with unique drug delivery characteristics. The application of PLGA nanoparticles (NPs) as intravenous (IV) sustained-release delivery vehicles for docetaxel can favorably modify pharmacokinetics, biofate, and pharmacotherapy of the drug in cancer patients. Surface modification of PLGA NPs with poly(ethylene glycol) (PEG) can further enhance NPs' long-circulating properties. Herein, an optimized fabrication approach has been used for the preparation of PLGA and PLGA-PEG NPs loaded with docetaxel for IV application. Both types of NP formulations demonstrated in vitro characteristics that were considered suitable for IV administration (with long-circulating sustained-release purposes). NP formulations were IV administered to an animal model, and docetaxel's pharmacokinetic and biodistribution profiles were determined and compared between study groups. PLGA and PEGylated PLGA NPs were able to modify the pharmacokinetics and biodistribution of docetaxel. Accordingly, the mode of changes made to pharmacokinetics and biodistribution of docetaxel is attributed to the size and surface properties of NPs. NPs contributed to increased blood residence time of docetaxel fulfilling their role as long-circulating sustained-release drug delivery systems. Surface modification of NPs contributed to more pronounced docetaxel blood concentration, which confirms the role of PEG in conferring long-circulation properties to NPs.

  2. The Effect of Antiseptic on 99mTc-DMSA Scans.

    Science.gov (United States)

    Firuzyar, Tahereh; Ghaedian, Tahereh

    2017-03-01

    Approximately 30 years ago, it has been suggested that chlorhexidine, which is used as antiseptic, can produce Tc colloid complex during Tc-dimercaptosuccinic acid (DMSA) preparation. However, in all cases of liver and spleen uptake in Tc-DMSA scan, it should still be kept in mind because of the introduction of new antiseptic brands with different formulation under various names. Our case is just a sample of this effect, which resulted from application of a new brand of antiseptic by technologists in our center that unintentionally led to low-quality Tc-DMSA scans for a period, and after restrict control of all other confounding factors in the preparation of kit, it was just resolved by changing antiseptic to ethanol.

  3. Selection of micronutrients used along with DMSA in the treatment of moderately lead intoxicated mice

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Yingjun [China Medical University, Department of Physiology, School of Basic Medicine, Shenyang, Liaoning (China); Yu, Fei; Zhi, Xuping; An, Li; Yang, Jun [China Medical University, Department of Nutrition and Food Hygiene, School of Public Health, Shenyang, Liaoning (China); Jin, Yaping; Lu, Chunwei; Li, Gexin [China Medical University, Department of Environmental and Occupational Health, School of Public Health, Shenyang, Liaoning (China)

    2008-01-15

    The objective of this study was to explore the optimum combination of micronutrients used with 2,3-dimercaptosuccinic acid (DMSA) in the treatment of moderately lead-intoxicated mice. Experiment was carried out based on the orthogonal design L{sub 8}(2{sup 7}) setting six factors with two different levels of each, and eight groups of mice were needed. Mice were exposed to lead by drinking water contaminated with 0.1% lead acetate for four consecutive weeks, and then supplemented by gavage with different combinations of micronutrients with and without DMSA as designed in the orthogonal table. Lead levels in blood, liver, kidney, brain and bone and activities of blood {delta}-aminolevulinic acid dehydratase (ALAD) were analyzed after cessation of supplementation. The results suggested that DMSA was the only factor which could decrease significantly lead levels in blood, liver, kidney and bone; calcium and ascorbic acid were the notable factors decreasing lead levels in blood, liver, kidney, bone and brain; zinc and calcium were the notable factors reversing the lead-inhibited activities of blood ALAD; taurine was the notable factor decreasing lead levels in kidney and brain; and thiamine was the notable factor decreasing lead levels in brain. The lowest lead level in blood, liver, kidney and bone was shown in the mice supplemented with combination of calcium and ascorbic acid along with DMSA. In conclusion, the optimum combination of micronutrients used with DMSA suggested in present study was calcium and ascorbic acid, which seemed to potentiate the chelating efficacy of DMSA in the treatment of moderately lead intoxicated mice. (orig.)

  4. Paediatric renal length measurements from ultrasound and DMSA scans: does clinical practice reflect theoretical normal values?

    International Nuclear Information System (INIS)

    Que, L.; Rutland, M.D.; Hassan, I.M.

    1999-01-01

    Full text: Renal length measurement is a routine part of ultrasound examination in children and those results are plotted on a normogram style graph, so that each child's results are compared to a normal range (mean ± 2 S.D.). Renal length measurements from the posterior oblique views of dimercaptosuccinic acid (DMSA) scans in our department have not always correlated well with the ultrasound measurements on the same patients. Renal lengths from the DMSA scans of 120 patients with apparently normal kidneys were recorded and used to generate a normogram of renal length at different ages (0.5-7 years). This DMSA normogram was compared to the ultrasound (US) normogram used in the Paediatric Radiology Department, and it showed slight differences in renal lengths (3-8 mm), but that the US normogram had smaller coefficients of variation (US = 6.6%, NM 8.3%), implying a 'tighter' normal range. 39 of these patients had DMSA and ultrasound measurements of renal length within 3 months, and these were studied first by calculating the mean and CV values for different age groups, and then by plotting individual renal lengths on the appropriate normograms. The measured data produced much greater variability in the ultrasound measurements than the DTPA measurements, and the individual points produced 4/78 (5.1%) abnormal results for DMSA, but 21/78 (26.9%) abnormal results for ultrasound. Thus, in routine clinical use, using patients with apparently normal kidneys, ultrasound was unable to match the 'normal range' set by their current normogram, but the nuclear medicine showed 5.1% of values outside the normal (DMSA) range, which was completely appropriate for a range of ± 2 standard deviations

  5. Evaluation of regenerative capacity after kidney ischemic/reperfustion injury using 99mTc-DMSA

    International Nuclear Information System (INIS)

    Kwak, W. J.; Kim, J. W.; Park, K. M.; Lee, S. W.; Ahn, B. C.; Lee, J. T.; Yoo, J. S.

    2007-01-01

    Acute renal failure can be caused by a reduced renal blood flow induced because of ischemic injury. The damaged kidney can be completely restored in structure and function. 99m Tc-DMSA binds to cortical tubules in kidney and its uptake has been suggested to indicate function of cortical mass. Herein, the generative capacity of kidney after bilateral or unilateral ischemia/reperfusion (I/R) injury was evaluated non-invasively by scintigraphic imaging. Three different animal models were used. One or both kidneys of mice were subjected ischemic for 30 min for unilateral or bilateral I/R model, respectively. In third model, one kidney was excised and the other kidney was subjected ischemic for 30 min to give nephrectomy model. At 1 hr, 1 d, 3 d, 1 w, 2 w, 3 w after reperfusion, 99m Tc-DMSA (27.7 MBq) was injected via tail vein. After 3 hr, the mice were scanned for 30 min with pinhole equipped gamma camera. The ratio of ROI counts of kidney to total counts was calculated. In unilateral I/R mouse, the 99m Tc-DMSA uptake of injured kidney was decreased continuously up to 3 w (13.9 to 7.7%), while uptake in normal kidney is slowly increased. In case of nephrectomy model, 99m Tc-DMSA uptake of injured kidney was rapidly restored within 1 w after I/R operation (8.5 to 30%). Bilateral model showed reduced 99m Tc-DMSA uptake at 1 d, but total uptake in both I/R kidney was also increase up to 30% after 1 w and the uptake was maintained up to 3 w. In unilateral model, the 99m Tc-DMSA uptake of injured kidney kept decreasing up to 3 w while normal kidney showed increased 99m Tc-DMSA uptake. The restoration of I/R kidney was not observed within 3 w. However, in case of animal models which have only I/R kidneys such as bilateral and nephrectomy models, the 99m Tc-DMSA uptake was restored within 1 w and the excised kidney size was also normal in contrast to much smaller I/R kidney of unilateral model

  6. Computer analysis of the amount functioning renal parenchyma according scintigraphy with 99mTc - DMSA

    International Nuclear Information System (INIS)

    Nyikolov, M.O.; Suprunyuk, D.O.; Chizhevs'kij, V.B.; Kamyins'ka, A.L.; Makarenko, A.V.

    2014-01-01

    To assess the definition of information values of focal changes in the renal parenchyma as a fuzzy set according kidney scan with 99m Tc-DMSA. The results of kidney scan of 99m Tc-DMSA 15 patients. It is shown that it is advisable to determine the degree of damage to the renal parenchyma as a fuzzy set, it count lower, upper limits of defeat and 'average' rating. Segmentation algorithms developed scintigraphic imaging of the kidneys are informative, independent and requires their simultaneous use

  7. 99mTc-DMSA scintigraphy in acute urinary tract infection in children

    International Nuclear Information System (INIS)

    Verboven, M.; Ingels, M.; Delree, M.; Piepsz, A.; Vrije Univ., Brussels

    1990-01-01

    24 children with symptomatic urinary tract infection (UTI) underwent systematically ultrasound studies (US) and 99m Tc-DMSA renal scans. Among the 15 patients considered as acute pyelonephritis (APN) on clinical grounds, the scan was abnormal in 12 cases, in contrast with only 1 abnormal scan in the clinical subgroup of the lower UTI. Among the 10 abnormal scans that were repeated later on, 6 did completely normalize. US showed only once a parenchymal appearance suggestive for APN. Our findings suggest that the DMSA scan has to be considered at present as the most sensitive imaging technique for the detection of APN. (orig.)

  8. Standardization of a method to calculate absolute renal uptake of {sup 99m} Tc-DMSA in children; Padronizacao do metodo para calculo da captacao renal absoluta do {sup 99m}Tc-DMSA em criancas

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Carla Rachel; Sapienza, Marcelo Tatit; Watanabe, Tomoco; Costa, Paulo Luiz Aguirre; Okamoto, Miriam Roseli Yoshie; Garcez, Alexandre Teles; Buchpiguel, Carlos Alberto [Sao Paulo Univ., SP (Brazil). Hospital das Clinicas. Servico de Medicina Nuclear]. E-mail: crachelo@usp.br; Machado, Beatriz Marcondes; Machado, Marcia Melo Campos [Paulo Univ., SP (Brazil). Faculdade de Medicina. Hospital Universitario; Liberato Junior, Waldyr de Paula

    2006-01-15

    Objective:To standardize a method and determine normal values for absolute renal uptake of 99m Tc-DMSA in children with normal creatinine clearance. Materials and methods: Twenty-two children (between 7 months and 10 years of age; mean 4.5 years) without clinical evidence of renal disease were studied using 99m Tc-DMSA scintigraphy. Eighteen had normal renal ultrasonography, micturating urethrocystography, creatinine clearance and visual interpretation of the scintigraphy with 99m Tc-DMSA. Four children were excluded, one with incomplete creatinine clearance and three due to reduction in the creatinine clearance. Absolute renal uptake of 99m Tc-DMSA (DMSA-Abs) was expressed as the fraction of the administered dose retained by each kidney six hours after administration of the radiopharmaceutical. Results: DMSA-Abs was 21.8 +- 3.2% for the right kidney and 23.1 +-3.3% for the left kidney. There was no correlation between renal uptake and the age groups studied, although there was a tendency to an increase in the creatinine clearance with age. Conclusion: Normal values of DMSA-Abs can be used as an additional parameter for the initial diagnostic evaluation and during follow-up of renal diseases, mainly when bilateral impairment of renal function is suspected or in a patient with a single functioning kidney (in which renal differential function is of limited value). (author)

  9. From Single Microparticles to Microfluidic Emulsification: Fundamental Properties (Solubility, Density, Phase Separation from Micropipette Manipulation of Solvent, Drug and Polymer Microspheres

    Directory of Open Access Journals (Sweden)

    Koji Kinoshita

    2016-11-01

    Full Text Available The micropipette manipulation technique is capable of making fundamental single particle measurements and analyses. This information is critical for establishing processing parameters in systems such as microfluidics and homogenization. To demonstrate what can be achieved at the single particle level, the micropipette technique was used to form and characterize the encapsulation of Ibuprofen (Ibp into poly(lactic-co-glycolic acid (PLGA microspheres from dichloromethane (DCM solutions, measuring the loading capacity and solubility limits of Ibp in typical PLGA microspheres. Formed in phosphate buffered saline (PBS, pH 7.4, Ibp/PLGA/DCM microdroplets were uniformly solidified into Ibp/PLGA microparticles up to drug loadings (DL of 41%. However, at DL 50 wt% and above, microparticles showed a phase separated pattern. Working with single microparticles, we also estimated the dissolution time of pure Ibp microspheres in the buffer or in detergent micelle solutions, as a function of the microsphere size and compare that to calculated dissolution times using the Epstein-Plesset (EP model. Single, pure Ibp microparticles precipitated as liquid phase microdroplets that then gradually dissolved into the surrounding PBS medium. Analyzing the dissolution profiles of Ibp over time, a diffusion coefficient of 5.5 ± 0.2 × 10−6 cm2/s was obtained by using the EP model, which was in excellent agreement with the literature. Finally, solubilization of Ibp into sodium dodecyl sulfate (SDS micelles was directly visualized microscopically for the first time by the micropipette technique, showing that such micellization could increase the solubility of Ibp from 4 to 80 mM at 100 mM SDS. We also introduce a particular microfluidic device that has recently been used to make PLGA microspheres, showing the importance of optimizing the flow parameters. Using this device, perfectly smooth and size-homogeneous microparticles were formed for flow rates of 0.167 mL/h for

  10. {sup 99M}Tc - DMSA renal scintigraphy in the diagnosis and follow-up of acute pyelonephritis in children

    Energy Technology Data Exchange (ETDEWEB)

    Wallin, L

    1997-06-01

    The aim of the present thesis was to define and evaluate a strategy for identification of children who are at risk of developing progressive renal lesions after acute pyelonephritis. Qualitative and quantitative evaluation standards were elaborated to improve the interpretation of DMSA scintigraphy. The normal DMSA distribution pattern, the average background uptake, and scintigraphic kidney length according to age were assessed in 95 presumably healthy kidneys. Furthermore, typical DMSA distribution patterns in acute pyelonephritis were assessed on 65 kidneys in 38 children, and typical DMSA distribution patterns of 152 kidneys with VUR in 101 children with and without previous pyelonephritis. Measurement of scintigraphic kidney length, width and volume was validated in piglets and on a kidney phantom. The scintigraphic kidney length was found to be an accurate measure of renal size, whereas kidney width and volume were less reliable, at least on small kidneys. Criteria of kidney swelling in acute pyelonephritis were defined, and found to be beneficial for identifying reinfections in the absence of clinical symptoms. In 34 children with acute pyelonephritis quantitative and qualitative DMSA scintigraphic findings were correlated to clinical symptoms and laboratory data, in the acute stage and at follow up. We found that quantitative DMSA scintigraphy in the acute stage of pyelonephritis and again after one year will identify children who are at risk of developing progressive renal lesions. Qualitative assessment of DMSA distribution pattern is not reliable enough in this respect. 116 refs., 7 figs.

  11. 99MTc - DMSA renal scintigraphy in the diagnosis and follow-up of acute pyelonephritis in children

    International Nuclear Information System (INIS)

    Wallin, L.

    1997-06-01

    The aim of the present thesis was to define and evaluate a strategy for identification of children who are at risk of developing progressive renal lesions after acute pyelonephritis. Qualitative and quantitative evaluation standards were elaborated to improve the interpretation of DMSA scintigraphy. The normal DMSA distribution pattern, the average background uptake, and scintigraphic kidney length according to age were assessed in 95 presumably healthy kidneys. Furthermore, typical DMSA distribution patterns in acute pyelonephritis were assessed on 65 kidneys in 38 children, and typical DMSA distribution patterns of 152 kidneys with VUR in 101 children with and without previous pyelonephritis. Measurement of scintigraphic kidney length, width and volume was validated in piglets and on a kidney phantom. The scintigraphic kidney length was found to be an accurate measure of renal size, whereas kidney width and volume were less reliable, at least on small kidneys. Criteria of kidney swelling in acute pyelonephritis were defined, and found to be beneficial for identifying reinfections in the absence of clinical symptoms. In 34 children with acute pyelonephritis quantitative and qualitative DMSA scintigraphic findings were correlated to clinical symptoms and laboratory data, in the acute stage and at follow up. We found that quantitative DMSA scintigraphy in the acute stage of pyelonephritis and again after one year will identify children who are at risk of developing progressive renal lesions. Qualitative assessment of DMSA distribution pattern is not reliable enough in this respect. 116 refs., 7 figs

  12. Standardization of a method to calculate absolute renal uptake of 99m Tc-DMSA in children

    International Nuclear Information System (INIS)

    Ono, Carla Rachel; Sapienza, Marcelo Tatit; Watanabe, Tomoco; Costa, Paulo Luiz Aguirre; Okamoto, Miriam Roseli Yoshie; Garcez, Alexandre Teles; Buchpiguel, Carlos Alberto; Machado, Beatriz Marcondes; Machado, Marcia Melo Campos; Liberato Junior, Waldyr de Paula

    2006-01-01

    Objective:To standardize a method and determine normal values for absolute renal uptake of 99m Tc-DMSA in children with normal creatinine clearance. Materials and methods: Twenty-two children (between 7 months and 10 years of age; mean 4.5 years) without clinical evidence of renal disease were studied using 99m Tc-DMSA scintigraphy. Eighteen had normal renal ultrasonography, micturating urethrocystography, creatinine clearance and visual interpretation of the scintigraphy with 99m Tc-DMSA. Four children were excluded, one with incomplete creatinine clearance and three due to reduction in the creatinine clearance. Absolute renal uptake of 99m Tc-DMSA (DMSA-Abs) was expressed as the fraction of the administered dose retained by each kidney six hours after administration of the radiopharmaceutical. Results: DMSA-Abs was 21.8 +- 3.2% for the right kidney and 23.1 +-3.3% for the left kidney. There was no correlation between renal uptake and the age groups studied, although there was a tendency to an increase in the creatinine clearance with age. Conclusion: Normal values of DMSA-Abs can be used as an additional parameter for the initial diagnostic evaluation and during follow-up of renal diseases, mainly when bilateral impairment of renal function is suspected or in a patient with a single functioning kidney (in which renal differential function is of limited value). (author)

  13. Synthesis of magnetic polymeric microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2010-05-13

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  14. Synthesis of magnetic polymeric microspheres

    International Nuclear Information System (INIS)

    Gervald, A Yu; Gritskova, Inessa A; Prokopov, Nikolai I

    2010-01-01

    The key types of magnetic polymeric microspheres are considered. Methods of synthesis of different types of magnetic nanoparticles and of preparation of stable magnetic fluids on their basis are outlined. The overview of the methods for the manufacture of magnetic polymeric microspheres is presented. The effect of the synthesis conditions on the characteristics of magnetic polymeric microspheres such as the diameter and the particle size distribution and the content of magnetic material is discussed by particular examples. The application fields of magnetic polymeric microspheres are briefly surveyed.

  15. Renal function study by sup(99m)Tc-DMSA renal scintigraphy in non-obstructive upper urinary tract infection

    International Nuclear Information System (INIS)

    Kawamura, Juichi; Itoh, Hitoshi; Wang, Pan-Chin; Hosokawa, Shinichi; Yoshida, Osamu

    1979-01-01

    Kidney function study was carried out in 90 patients with non-obstructive upper urinary tract infection using sup(99m)Tc-DMSA (dimercaptosuccinic acid) renal scintigraphy. sup(99m)Tc-DMSA renal scintigram demonstrated well pyelonephritic cortical lesions which were not easily visualized on IVP. A variety of sup(99m)Tc-DMSA renal uptake paralleled the grading of pyelonephritic changes in IVP, however, there was a discrepancy between some of grade II pyelonephritic changes in reflux kidneys and DMSA renal uptake. This may be partly attributed to hydrodynamic effects of VUR in addition to inflammatory changes. The severity of reflux and changes in pelviocaliceal system on VCG also paralleled DMSA renal uptake in reflux kidneys. A ratio of sup(99m)Tc-DMSA renal uptake in the healthy side to that in pathological side was observed in 23 cases with VUR before and after the anti-VUR operation was performed. In patients with more than 3.5 of preoperative DMSA uptake ratio, there were few increments postoperatively in kidney functions of the pathological side, while the contralateral healthy kidney showed a compensatory increase in kidney function. This DMSA renal uptake ratio between healthy and pathological side seems to be one of predictable determinants for postoperative recovery of the pathological side. Thus, by comparing the DMSA uptake between right and left kidney in the chronic course or pre- and postoperative periods, an effect of renal function in the pathological side on that in the healthy side was investigated from the point of renal counterbalance. (author)

  16. 99mTc-DMSA Uptake in a Sister Mary Joseph's Nodule From Ovarian Cancer.

    Science.gov (United States)

    Naddaf, Sleiman; Azzumeea, Fahad; Fahad Alzayed, Mohammed

    2016-12-01

    A 50-year-old woman with ovarian cancer underwent Tc-DMSA scan to evaluate the functional status of the right hydronephrotic kidney. The images incidentally revealed a well-defined focus of mild radiotracer uptake at the midanterior abdominal wall, which correlated with a metastatic Sister Mary Joseph's nodule seen on CT performed a week earlier.

  17. DMSA SPECT imaging using oblique reconstruction in a paediatric population - benefits and technical considerations

    International Nuclear Information System (INIS)

    Parsons, G.; Ford, M.; Crisp, J.; Bernard, E.; Howman-Giles, R.

    1997-01-01

    Full text: DMSA renal scans are frequently requested for the diagnosis and follow-up of acute pyelonephritis and cortical scarring. This study was designed to:- 1. evaluate oblique reconstruction of DMSA SPECT over standard plane reconstruction and planar imaging; and 2. report on the technical aspects important in obtaining high quality DMSA SPECT, particularly in neonates. Over seven months, 210/231 (91 %) of DMSA scans were performed with SPECT on children from age nine days to 16 years, the median age being 2.5 years. 65 patients (31 %) were under one year and 39 (18%) were under six months. Planar and SPECT imaging with standard plane reconstruction and oblique reorientation was performed on the Siemens triple-headed gamma camera. High quality SPECT images were obtained on the smallest babies using a paediatric palette, and were of comparable quality to those of older children. At the time of reporting, the nuclear medicine physician assessed the diagnostic value of the three types of date presented: (1) planar images; (2) standard plane SPECT reconstruction; and (3) oblique SPECT reconstruction. Cortical defects were identified separately for upper, middle and lower poles. Three physicians concluded that high quality SPECT is superior to planar images when assessing the renal cortex. In addition, oblique reorientation is superior to standard reconstruction, particularly at the upper and lower poles. SPECT is now performed routinely on patients of all ages, and the oblique sagittal and coronal reorientation is now used in place of the standard reconstruction

  18. The Hydrophobic Region of the DmsA Twin-Arginine Leader Peptide Determines Specificity with Chaperone DmsD

    OpenAIRE

    Winstone, Tara M. L.; Tran, Vy A.; Turner, Raymond J.

    2013-01-01

    The system specific chaperone DmsD plays a role in the maturation of the catalytic subunit of dimethyl sulfoxide (DMSO) reductase, DmsA. Pre-DmsA contains a 45-amino acid twin-arginine leader peptide that is important for targeting and translocation of folded and cofactor-loaded DmsA by the twin-arginine translocase. DmsD has previously been shown to interact with the complete twin-arginine leader peptide of DmsA. In this study, isothermal titration calorimetry was used to investigate the the...

  19. Fabrication of Nanostructured PLGA Scaffolds Using Anodic Aluminum Oxide Templates

    OpenAIRE

    Hsueh , Cheng-Chih; Wang , Gou-Jen; Hsu , Shan-Hui; Hung , Huey-Shan

    2008-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838); International audience; PLGA (poly(lactic-co-glycolic acid)) is one of the most used biodegradable and biocompatible materials. Nanostructured PLGA even has great application potentials in tissue engineering. In this research, a fabrication technique for nanostructured PLGA membrane was investigated and developed. In this novel fabrication approach, an anodic aluminum oxide (AAO) film was use as the...

  20. Optimization of labelling procedure of {sup 188}rE-DMSA(v)

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Danielle M.; Brambilla, Tania P.; Reis, Nicoli F.; Osso Junior, Joao A., E-mail: jaosso@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Radionuclide therapy (RNT) is emerging as an important tool of nuclear medicine. Apart from the well established {sup 131}I, several other promising radionuclides have been identified, among them {sup 188}Re, {sup 90}Y and {sup 177}Lu. {sup 188}Re has received a lot of attention in the past decade, due to its favourable nuclear characteristics [t{sub 1/2} 16.9 h, E{sub b}eta{sub m}ax 2.12 MeV and E{sub g}amma 155 keV (15%) suitable for imaging, including the fact that it is carrier-free and can be obtained cost-effectively through the generator {sup 188}W-{sup 188}Re. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of medullary thyroid carcinoma, bone metastases, soft tissue and others tumors. The aim of this work is to evaluate two labeling procedures for the preparation of {sup 188}Re-DMSA(V). The first method was prepared using a commercial kit of DMSA(III) for labeling with {sup 99m}Tc at high temperature (100 deg C). The second method was prepared in a vial containing 2.5 mg of DMSA, 1.00 mg of SnCl{sub 2}.2H{sub 2}O and 10 mg of sodium oxalate, 10 mg of cyclodextrin, in a total volume of 2.0 mL. The pH was adjusted to 3 with 37% HCl. After labeling the solution was stirred and incubated for 30 min at room temperature. The radiochemical purity was determined using TLC-SG developed with two different solvent systems: Acetone and glycine. Preliminary results for both methods of labeling {sup 188}Re-DMSA(V) showed that the labeling yield was >95%. Further experiments are also necessary to optimize the labeling methodology of {sup 188}Re-DMSA(V).author)

  1. Biokinetics and dosimetric studies about 99mTc(V)DMSA distribution

    International Nuclear Information System (INIS)

    Correia, M.B.L.; Magnata, S.S.L.P.; Silva, I.M.S.; Lima, F.F.; Catanho, M.T.J.A.

    2008-01-01

    Research for radiodiagnostic agents should considerate biological critical parameters as half-life effective, target/not target uptake ratio and metabolites that together will determinate the biokinetic. Each parameter give own contribution in the absorbed dose. The dimercaptosuccinic acid (DMSA) labeled with 99m Tc(VN) is a radiopharmaceutical which has well established role in medullar thyroid carcinoma and has been proposed in complementary evaluation of bone metastasis. The aim of this work was study the biokinetics and dosimetry of 99m Tc(V)-DMSA by animal model. The 99m Tc(V)-DMSA was prepared by (III)DMSA kit alkalized. The methodology used mice, 70 days old, both males and females. The animals (n=5) received 99m Tc(V)DMSA administered IV (tail vein). After determinate times (30 min, 1h, 5h and 12h) the animals were sacrificed, the organs (blood, lungs, kidneys, muscle and bone) were excised and the activities were measured by a gamma counter. The results were evaluated based on %activity/g and the absorbed dose was estimated by extrapolation of data from animal to human, using the residence time to each organ in the MIRDOSE 3.0 program. The results show that the majority of organs reaches the top uptake at 30 min, the kidney has the greatest uptake in this time, (4.81 ± 1.38) % activity per gram, while the bone presents its highest uptake at 1h (5.49 ± 0.47)% activity per gram, after 1h all the organs had activity exponential decrease. About the absorbed dose estimated to human scale, the preliminary results showed higher value to bone, being the soft tissue dose relatively low. These dose values, however, are submitted to biological implications which are under studying yet. The biokinetic profile of 99m Tc(V)-DMSA, prepared from a DMSA kit by IPEN, was well established, allowing quantifying of residence time, while the dosimetric model presented preliminary data which directs to new analyzes

  2. Morphological classification of Renal Disease Using 99mTc-DMSA Scintigram

    International Nuclear Information System (INIS)

    Moon, Tae Yong

    1991-01-01

    99m Tc-DMSA renal scan has been evaluated not only the renal functional cell mass but also some anatomical structures at a loss of the renal parenchymal function. The author classified a renal morphology of the posterior image of 99m Tc-DMSA renal scan as the groups of symmetic and asymmetric morphology, the groups of the large, normal and small sized kidneys, the groups of the central photon defects (PD) which could be noted in a dilated pelvocalyceal system due to obstructive uropathy and the cortical photon defects (CD) due to focal parenchymal lesions or scars after a loss of function and the last groups of the single and multiple CD for a suggestion of the clinical usefulness. Regarding to measurement of norrnal renal size, the longest size of the kidneys were evaluated with 5 cm of a lead scale on the posterior renal image, and those were decided to the limits beteen 104.1 and 119. 4 mm as comparison with the renal size of intravenous pyelogram (IVP) in 59 cases who were underwent 99m Tc-DMSA and IVP concommitantly. Among 85 cases of PD in 99m Tc-DMSA renal scan, the 61 (71.8%) were cases of a dilated pelvocalyceal system related with obstructive uropathy, meanwhile the 28 (27.0%) of 162 cases with CD were cases of obstructive and infectious uropathy. The probability of a presence of some uropathy in cases of CD were 99.3%, meanwhile that of the presence of CD in cases of some uropathy were 37.9%. Besides, there were some specific anatomical findings such as polycystic kidneys with symmetric enlarged kidneys with multiple CD and the kidneys of chronic renal failure and/or hypertension with syrnmetric small size in 99m Tc-DMSA renal scan.

  3. 99mTc-DMSA renal scintigraphy in children with urinary tract infections and vesicouretheric reflux

    International Nuclear Information System (INIS)

    Ajdinovic, B.A.; Baskot, B.B.; Spaic, R.S.; Markovic, S.M.

    2002-01-01

    Aim: Comparison of results 99mTc-DMSA renal scintigraphy in children with urinary tract infections (UTI) and vesicouretheric reflux (VUR) to results in children with UTI without VUR. Material and Methods: 99mTc-DMSA renal scintigraphy was done in 170 children with UTI, in 88 of whom were presented VUR, proved by micturating cysto-urethrography (MCU). In 13 of them grade of VUR was I, in 30 grade II, in 23 grade was III, in 17 IV, and in 5 grade of was V. In 82 children with UTI, VUR could not be detected by MCU. Findings of 99mTc-DMSA renal scintigraphy were classified as: 1. normal, 2. probably normal, 3. equivocal, 4. probably abnormal, 5. abnormal. Results:In patients with UTI and VUR incidence of abnormal findings was 49% (43/88), normal 43% (38/88), and equivocal findings were 8% (7/88). The highest abnormal finding incidence was found in 5 patients with VUR grade V (100%). In VUR grade IV incidence of abnormal findings was 71%. In patients with VUR grade I 77% findings were normal, in patients with VUR grade II 53% findings were normal, and in patients with VUR grade III 30% findings were normal. In patients with UTI without VUR incidence of abnormal findings was 10% (8/82), normal 83% (68/82), and equivocal findings were 7% (6/82). Conclusion: In patients with UTI and VUR incidence of abnormal 99mTc-DMSA renal scintigraphy findings was significantly higher, particularly in children with higher grade of VUR, than in patients with UTI without VUR (p<0,001). Results of our study confirmed importance of 99mTc-DMSA renal scintigraphy in investigation of children with UTI

  4. Amikacin loaded PLGA nanoparticles against Pseudomonas aeruginosa.

    Science.gov (United States)

    Sabaeifard, Parastoo; Abdi-Ali, Ahya; Soudi, Mohammad Reza; Gamazo, Carlos; Irache, Juan Manuel

    2016-10-10

    Amikacin is a very effective aminoglycoside antibiotic but according to its high toxicity, the use of this antibiotic has been limited. The aim of this study was to formulate and characterize amikacin loaded PLGA nanoparticles. Nanoparticles were synthetized using a solid-in-oil-in-water emulsion technique with different ratio of PLGA 50:50 (Resomer 502H) to drug (100:3.5, 80:3.5 and 60:3.5), two different concentrations of stabilizer (pluronic F68) (0.5% or 1%) and varied g forces to recover the final products. The most efficient formulation based on drug loading (26.0±1.3μg/mg nanoparticle) and encapsulation efficiency (76.8±3.8%) was the one obtained with 100:3.5 PLGA:drug and 0.5% luronic F68, recovered by 20,000×g for 20min. Drug release kinetic study indicated that about 50% of the encapsulated drug was released during the first hour of incubation in phospahte buffer, pH7.4, 37°C, 120rpm. Using different cell viability/cytotoxicity assays, the optimized formulation showed no toxicity against RAW macrophages after 2 and 24h of exposure. Furthermore, released drug was active and maintained its bactericidal activity against Pseudomonas aeruginosa in vitro. These results support the effective utilization of the PLGA nanoparticle formulation for amikacin in further in vivo studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Bone Regeneration from PLGA Micro-Nanoparticles.

    Science.gov (United States)

    Ortega-Oller, Inmaculada; Padial-Molina, Miguel; Galindo-Moreno, Pablo; O'Valle, Francisco; Jódar-Reyes, Ana Belén; Peula-García, Jose Manuel

    2015-01-01

    Poly-lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules and as component of tissue engineering applications. Its properties and versatility allow it to be a reference polymer in manufacturing of nano- and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules. It additionally facilitates and extends its use to encapsulate biomolecules such as proteins or nucleic acids that can be released in a controlled way. This review focuses on the use of nano/microparticles of PLGA as a delivery system of one of the most commonly used growth factors in bone tissue engineering, the bone morphogenetic protein 2 (BMP2). Thus, all the needed requirements to reach a controlled delivery of BMP2 using PLGA particles as a main component have been examined. The problems and solutions for the adequate development of this system with a great potential in cell differentiation and proliferation processes under a bone regenerative point of view are discussed.

  6. Progesterone PLGA/mPEG-PLGA Hybrid Nanoparticle Sustained-Release System by Intramuscular Injection.

    Science.gov (United States)

    Xie, Bin; Liu, Yang; Guo, Yuting; Zhang, Enbo; Pu, Chenguang; He, Haibing; Yin, Tian; Tang, Xing

    2018-02-14

    To prepare sustained-release PLGA/mPEG-PLGA hybrid nanoparticles of progesterone (PRG), and evaluate the descending required administration dosage in vivo. PRG hybrid nanoparticles (PRG H-NPs) based on PLGA/mPEG-PLGA were compared with PRG nanoparticles (PRG-NPs) of pure PLGA as the matrix and PRG-oil solutions. Nanoparticles (NPs) were formed by the method of nanoemulsion, and the pharmacokinetics of the sustained-release PRG H-NPs in male Sprague dawley (SD) rats were investigated. The rats were randomly divided into four groups, each group received: single dose of PRG H-NPs (14.58 mg/kg, i.m.) and PRG-NPs (14.58 mg/kg, i.m.), repeated dosing for 7 days of PRG-oil (2.08 mg/kg, i.m.) solution (Oil-L) and a higher dosage of PRG-oil (6.24 mg/kg, i.m.) solution (Oil-H), respectively. In the pharmacokinetic test, the PRG H-NPs exhibited a comparatively good sustained-release effect against the PRG-NPs without mPEG-PLGA and PRG-oil solution. The pharmacokinetic parameters of the PRG H-NPs, PRG-NPs, Oil-L and Oil-H were AUC 0-t (ng·h·mL -1 ) 8762.1, 1546.1, 1914.5, and 12,138.9, t 1/2 (h)52.7, 44.1, 8.4 and 44.6 respectively. Owing to the modification of PEG, PRG H-NPs can act as safe delivery platforms for sustained-release of drugs with a lower dosage required.

  7. Comparison of 99Tcm(V)-DMSA and 99Tcm-MIBI scintigraphy in medullary thyroid carcinoma

    International Nuclear Information System (INIS)

    Deng Bo; Xiao Huan; Chen Xiaofeng; Chen Huaming

    2004-01-01

    SPECT scintigraphy is used in 62 patients with medullary thyroid carcinoma (MTC), which are divided into two groups: 32 patients by 99 Tc m (V)-DMSA and 30 patients by 99 Tc m -MIBI. The qualitative analysis and half quantitative analysis are performed to the early and delayed images. Comparing the results with two groups, there is no difference in the masculine rate of MTC primary focus, but the results of 99 Tc m (V)-DMSA scintigraphy is obviously larger than 99 Tc m -MIBI by half quantitative analysis. The results show that the 99 Tc m (V)-DMSA scintigraphy is more predominant than the 99 Tc m -(V)-DMSA scintigraphy may be superior to 99 Tc m -MIBI in MTC primary focus and metastasis focus before surging for MTC patients. (authors)

  8. An investigation into the effects of residual water on the glass transition temperature of polylactide microspheres using modulated temperature DSC.

    Science.gov (United States)

    Passerini, N; Craig, D Q

    2001-05-18

    The objective of the study was to ascertain residual water levels in polylactide and polylactide-co-glycolide microspheres prepared using the solvent evaporation technique and to investigate the effects of that water on the glass transitional behaviour of the microspheres. Microspheres were prepared from polylactic acid (PLA) and polylactide-co-glycolide (PLGA) 50:50 and 75:25 using a standard solvent evaporation technique. The glass transition was measured as a function of drying conditions using modulated temperature DSC. The microspheres were found to contain very low levels of dichloromethane, while residual water levels of up to circa 3% w/w were noted after freeze or oven drying, these levels being higher for microspheres containing higher glycolic acid levels. The residual water was found to lower the T(g) following the Gordon-Taylor relationship. The data indicate that the microparticles may retain significant water levels following standard preparation and drying protocols and that this drying may markedly lower the T(g) of the spheres.

  9. Can MRI replace DMSA in the detection of renal parenchymal defects in children with urinary tract infections?

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Eoin C.; Ryan, Stephanie; McCourbrey, Siobhan; O' Connor, Rachel; Donoghue, Veronica [Children' s University Hospital, Department of Radiology, Dublin (Ireland); Awan, Atif [Children' s University Hospital, Department of Paediatrics, Dublin (Ireland)

    2005-03-01

    Renal parenchymal defects may be a consequence of urinary tract infections (UTI) in childhood. MRI is a non-radiation imaging modality compared with DMSA scanning. To compare DMSA with MRI for the detection of renal parenchymal defects in children presenting for radiological investigation after a first UTI. Both DMSA and MRI were performed at the same appointment in 37 children (aged 4 months-13 years; mean 4.5 years) with a history of UTI. Both planar and SPECT DMSA were performed. MRI of the kidneys employed axial and coronal T1-, T2- and fat-saturated T1-weighted (T1-W) sequences. Some children had imaging after IV contrast medium. The coronal fat-saturated T1-W sequence was the best sequence and it detected all the findings on MRI. MRI had a sensitivity of 77% and a specificity of 87% for the detection of a scarred kidney using DMSA as the gold standard. MRI diagnosed pyelonephritis in two children that had been interpreted as scarring on DMSA. Renal MRI using a single, coronal, fat-saturated T1-W sequence is a rapid, accurate and minimally invasive technique for the detection of renal scarring that does not employ ionizing radiation. (orig.)

  10. The Clinical Role of 99mTc-(V)-DMSA Imaging in Patients with Head and Neck Cancer

    International Nuclear Information System (INIS)

    Bae, Sun Kun; Lee, Jae Tae; Park, June Sik

    1995-01-01

    99m Tc-(V)-DMSA is a tumor seeking agent that has been used to image medullary carcinoma of thyroid, soft tissue sarcoma and lung cancer. This study was designed to assess the clinical role of DMSA in the diagnosis of head and neck cancers. We has evaluated the diagnostic efficacy of planar and SPECT imaging using 99m Tc-(V)-DMSA. Sixty-eight patients with head and neck mass were included in this study. All subjects were diagnosed by biopsy or surgery. Planar and SPECT images were obtained at 2 or 3 hour after intravenous injection of 740 MBq(20 mCi) 99m Tc-(V)-DMSA. Seventeen patients also underwent SPECT imaging using dual head camera. The diagnostic sensitivity of 99m Tc-(V)-DMSA planar and SPECT imaging was 65% and 90%, and specificity was 80% and 66%, respectively. The sensitivity of planar imaging in squamous cell carcinoma was similar to overall sensitivity. Six metastatic lesion were first diagnosed by scintigraphy. But benign lesions such as Kikuchi syndrome, tuberculous lymphadenitis also revealed increased uptake. 99m Tc-(V)-DMSA imaging seems to be a promising method in the evaluation of patients with head and neck mass. We recommend SPECT imaging to delineate anatomic localization of the lesion.

  11. Can MRI replace DMSA in the detection of renal parenchymal defects in children with urinary tract infections?

    International Nuclear Information System (INIS)

    Kavanagh, Eoin C.; Ryan, Stephanie; McCourbrey, Siobhan; O'Connor, Rachel; Donoghue, Veronica; Awan, Atif

    2005-01-01

    Renal parenchymal defects may be a consequence of urinary tract infections (UTI) in childhood. MRI is a non-radiation imaging modality compared with DMSA scanning. To compare DMSA with MRI for the detection of renal parenchymal defects in children presenting for radiological investigation after a first UTI. Both DMSA and MRI were performed at the same appointment in 37 children (aged 4 months-13 years; mean 4.5 years) with a history of UTI. Both planar and SPECT DMSA were performed. MRI of the kidneys employed axial and coronal T1-, T2- and fat-saturated T1-weighted (T1-W) sequences. Some children had imaging after IV contrast medium. The coronal fat-saturated T1-W sequence was the best sequence and it detected all the findings on MRI. MRI had a sensitivity of 77% and a specificity of 87% for the detection of a scarred kidney using DMSA as the gold standard. MRI diagnosed pyelonephritis in two children that had been interpreted as scarring on DMSA. Renal MRI using a single, coronal, fat-saturated T1-W sequence is a rapid, accurate and minimally invasive technique for the detection of renal scarring that does not employ ionizing radiation. (orig.)

  12. Electrospinnability of poly lactic-co-glycolic acid (PLGA)

    DEFF Research Database (Denmark)

    Liu, Xiaoli; Baldursdottir, Stefania G.; Aho, Johanna

    2017-01-01

    PURPOSE: In this study, the electrospinnability of poly(lactic-co-glycolic acid) (PLGA) solutions was investigated, with a focus on understanding the influence of molecular weight of PLGA, solvent type and solvent composition on the physical properties of electrospun nanofibers. METHOD: Various s...

  13. Prognostic value of the acute DMSA scan in hospitalized children with urinary tract infection

    Directory of Open Access Journals (Sweden)

    Hashemian H

    2008-12-01

    Full Text Available "nBackground: Urinary Tract Infection (UTI is one of the major etiological factors of permanent kidney impairment, resulting in renal scarring and severe and pernicious side effects, such as arterial hypertension and renal failure. The purpose of this study was to clarify the impression of renal parenchyma involvement by first UTI (on the basis of acute DMSA scan and vesicoureteral reflux (VUR-on the basis of VCUG/ RNC on the renal scar formation (on the basis of late DMSA scan. "nMethods: Children diagnosed with their first UTI at the Children's Hospital Medical Center, Tehran, Iran, were evaluated. For each patient, we recorded age, sex, results of VCUG/RNCs and acute DMSA scan, as well as those of a late DMSA scan performed 4-6 months later. The results of acute and late DMSA scans were compared along with the results of VCUG/RNCs. "nResults: This study included a total of 103 children, of whom 16 (15.5% were boys and 87 (84.5% were girls. The mean age was 27.2±27.7 months. The frequency of renal scars in kidneys with mild (28.6%, 8.7% and moderate (33.3%, 18.2% pyelonephritis with or without VUR was not significantly different, while the frequency of renal scars in kidneys with severe pyelonephritis (84.6%, 23.1% in the presence of VUR was significantly higher than non-refluxing kidneys with severe pyelonephritis (p=0.005. Furthermore, the frequency of renal scars in refluxing kidneys increased significantly with the severity of pyelonephritis (normal 8.3%, mild 28.6%, moderate 33.3%, and severe 84.6%; p=0.001. This pattern was not significant in non-refluxing kidneys (0%, 10.3%, 18.2%, and 23.1%, respectively; p=0.062. "nConclusion: The present study indicates that the incidence of renal scarring increases with pyelonephritis severity in patients with VUR. Furthermore, we can estimate the risk of renal scar formation from the results of acute DMSA scan and VCUG/RNC.

  14. EFFECT OF DMPS AND DMSA ON THE PLACENTAL AND FETAL DISPOSITION OF METHYLMERCURY

    Science.gov (United States)

    Bridges, Christy C.; Joshee, Lucy; Zalups, Rudolfs K.

    2009-01-01

    Methylmercury (CH3Hg+) is a serious environmental toxicant. Exposure to this metal during pregnancy can cause serious neurological and developmental defects in a developing fetus. Surprisingly, little is known about the mechanisms by which mercuric ions are transported across the placenta. Although it has been shown that 2,3-dimercaptopropane-1-sulfonate (DMPS) and 2,3-dimercaptosuccinic acid (DMSA) are capable of extracting mercuric ions from various organs and cells, there is no evidence that they are able to extract mercury from placental or fetal tissues following maternal exposure to CH3Hg+. Therefore, the purpose of the current study was to evaluate the ability of DMPS and DMSA to extract mercuric ions from placental and fetal tissues following maternal exposure to CH3Hg+. Pregnant Wistar rats were exposed to CH3HgCl, containing [203Hg], on day 11 or day 17 of pregnancy and treated 24 h later with saline, DMPS or DMSA. Maternal organs, fetuses, and placentas were harvested 48 h after exposure to CH3HgCl. The disposition of mercuric ions in maternal organs and tissues was similar to that reported previously by our laboratory. The disposition of mercuric ions in placentas and fetuses appeared to be dependent upon the gestational age of the fetus. The fetal and placental burden of mercury increased as fetal age increased and was reduced by DMPS and DMSA, with DMPS being more effective. The disposition of mercury was examined in liver, total renal mass, and brain of fetuses harvested on gestational day 19. On a per gram tissue basis, the greatest amount of mercury was detected in the total renal mass of the fetus, followed by brain and liver. DMPS and DMSA reduced the burden of mercury in liver and brain while only DMPS was effective in the total renal mass. The results of the current study are the first to show that DMPS and DMSA are capable of extracting mercuric ions, not only from maternal tissues, but also from placental and fetal tissues following maternal

  15. Formulation, radiopharmaceutical kinetics and dosimetry of the {sup 188}Re(V)-DMSA complex; Formulacion, radiofarmacocinetica y dosimetria del complejo {sup 188}Re(V)-DMSA

    Energy Technology Data Exchange (ETDEWEB)

    Garcia S, L; Ferro F, G [Departamento de Materiales Radiactivos. Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Salazar, Estado de Mexico (Mexico); Murphy, C.A. de; Pedraza L, M [Departamento de Medicina Nuclear, Instituto Nacional de la Nutricion, Salvador Zubiran, Mexico D.F. (Mexico); Azorin N, J [Departamento de Fisica, Universidad Autonoma Metropolitana Iztapalapa, Mexico D.F. (Mexico)

    1999-07-01

    It was developed through experimental design (ANOVA), a formulation to prepare the {sup 188} Re(V)-Dmsa complex. Likewise, there were realized studies of radiopharmaceutical kinetics and internal dosimetry in animals, its normal and with induced tumors, considering an open bi compartmental model using the MIRD methodology. The {sup 188} Re(V)-Dmsa complex was obtained with a radiochemical purity greater than 95% incubating 30 min at 90 Centigrade under the following formulation: [SnCl{sub 2}] = 1.4 mg/ml, [ascorbic acid] = 0.5 mg/ml, p H = 2.0 - 3.0. The stability test of the formulation, shows that after 48 h of its preparation, does not produce radiolytic degradation neither chemical decomposition. The radiopharmaceutical kinetics data show an average residence time 7.2h, velocity constant {alpha} = 0.6508h{sup -1} and {beta} = 0.1046 h{sup -1} with an apparent distribution volume 6.9 l. The main elimination via was renal and it was observed osseous caption with an accumulated activity 522.049 {+-} 62 MBq h (residence time 14.1094 {+-} 1.69h). In according with the dosimetric calculations, by each 37 MBq injected, the equivalent dose at the tumor was 9.67{+-} 0.33 Sv/g, for an effective dose 0.292 {+-} 0.0017 mSv/MBq. The images obtained in the gamma camera of the mice with induced tumors, show that do not have significant accumulation in the metabolic organs. The caption in bone and in tumors induced of the {sup 188} Re(V)-Dmsa complex, show its potential for be used as a palliative agent for pain in patients with osseous metastasis and in the treatment of tumors of soft tissue. (Author)

  16. CO2-assisted high pressure homogenization: a solvent-free process for polymeric microspheres and drug-polymer composites.

    Science.gov (United States)

    Kluge, Johannes; Mazzotti, Marco

    2012-10-15

    The study explores the enabling role of near-critical CO(2) as a reversible plasticizer in the high pressure homogenization of polymer particles, aiming at their comminution as well as at the formation of drug-polymer composites. First, the effect of near-critical CO(2) on the homogenization of aqueous suspensions of poly lactic-co-glycolic acid (PLGA) was investigated. Applying a pressure drop of 900 bar and up to 150 passes across the homogenizer, it was found that particles processed in the presence of CO(2) were generally of microspherical morphology and at all times significantly smaller than those obtained in the absence of a plasticizer. The smallest particles, exhibiting a median x(50) of 1.3 μm, were obtained by adding a small quantity of ethyl acetate, which exerts on PLGA an additional plasticizing effect during the homogenization step. Further, the study concerns the possibility of forming drug-polymer composites through simultaneous high pressure homogenization of the two relevant solids, and particularly the effect of near-critical CO(2) on this process. Therefore, PLGA was homogenized together with crystalline S-ketoprofen (S-KET), a non-steroidal anti-inflammatory drug, at a drug to polymer ratio of 1:10, a pressure drop of 900 bar and up to 150 passes across the homogenizer. When the process was carried out in the presence of CO(2), an impregnation efficiency of 91% has been reached, corresponding to 8.3 wt.% of S-KET in PLGA; moreover, composite particles were of microspherical morphology and significantly smaller than those obtained in the absence of CO(2). The formation of drug-polymer composites through simultaneous homogenization of the two materials is thus greatly enhanced by the presence of CO(2), which increases the efficiency for both homogenization and impregnation. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Review: microspheres for radioembolization therapy

    International Nuclear Information System (INIS)

    Zhao Mingqiang; Xu Shuhe

    2007-12-01

    Radioembolization of liver cancer has been proven to be an effective therapy in nuclear medicine. The yttrium-90 glass microspheres has been used to treat both primary and metastatic liver tumors in clinic which shown encouraging results. The preparation, stability, degradation and application for medical purpose of radioactive microspheres are reviewed. At first, the theory of radioem- bolization treating cancer is discussed; and then three major radiolabled micro- sphere materials are expounded: viz. glass, resin-based and polymer-based; Future improvements in the preparation and use of radioactive microspheres are prospected at last. (authors)

  18. Review: microspheres for radioembolization therapy

    Energy Technology Data Exchange (ETDEWEB)

    Mingqiang, Zhao; Shuhe, Xu [China Inst. of Atomic Energy, Beijing (China)

    2007-12-15

    Radioembolization of liver cancer has been proven to be an effective therapy in nuclear medicine. The yttrium-90 glass microspheres has been used to treat both primary and metastatic liver tumors in clinic which shown encouraging results. The preparation, stability, degradation and application for medical purpose of radioactive microspheres are reviewed. At first, the theory of radioem- bolization treating cancer is discussed; and then three major radiolabled micro- sphere materials are expounded: viz. glass, resin-based and polymer-based; Future improvements in the preparation and use of radioactive microspheres are prospected at last. (authors)

  19. Development of methods of labeling pentavalent DMSA with {sup 99m}Tc and {sup 188}Re; Desenvolvimento de metodos para marcacao de DMSA pentavalente com {sup 99m}Tc e {sup 188}Re

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Tania de Paula, email: jtoniolo@ipen.br

    2009-07-01

    Technetium-99 m is the most useful radionuclide in diagnostic imaging procedures in Nuclear Medicine, more than 80 percent of radiopharmaceuticals are {sup 99m}Tc-labeled compounds. {sup 99m}Tc-DMSA(V) has been used for imaging of soft tissue, head and neck tumors. It shows a particularly high specificity for medullary thyroid carcinoma and bone metastases in a variety of cancers. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of these tumors. The aim of this work is the development of methods of labeling DMSA(V) with {sup 99m}Tc and {sup 188}Re. {sup 99m}Tc-DMSA(V) can be prepared by two methods. One of them is the indirect one, through the use of a commercial kit of DMSA (III), by adjusting the pH from 2.5 to {approx} 8.5 with NaHCO{sub 3}. This method was evaluated and optimized presenting high labeling yields. The other method is the direct one, through the preparation of a lyophilised kit ready for labeling with {sup 99m}Tc, being the method of interest of this work, due to the easy of its clinical use. The most adequate formulation of the kit was: 1.71 mg of DMSA, 0.53 mg of SnCl{sub 2}.2H{sub 2}O and 0.83 mg of ascorbic acid (pH 9). Labeling yields higher than 95% were achieved labeling this kit with 1 to 2 m L of {sup 99m}Tc with activities up to 4736 MBq (128 mCi). The kit was stable up to 6 months and biodistribution studies confirmed the quality of the DMSA (V) labeled with {sup 99m}Tc using this kit. The reduction potential of Re is lower than the one for Tc, so the labeling conditions of {sup 188}Re-DMSA(V) are different from the ones used for {sup 99m}Tc- DMSA(V). {sup 188}Re-DMSA(V) is prepared in acid solution, that makes it possible to use the DMSA (III) commercial kit developed for labeling with {sup 99m}Tc, prepared in pH 2.5, for labeling with {sup 188}Re. Labeling yields higher than 95% were

  20. Triple Detector SPECT Imaging with 99mTc-DMSA in Adult Patients with Urinary Tract Infection

    International Nuclear Information System (INIS)

    Ryu, Jin Sook; Bea, Woon Gyu; Moon, Dae Hyuk; Lee, Myung Hae; Kim, Soon Bae; Park, Su Kil; Park, Jung Sik; Hong, Chang Gi; Cho, Kyung Sik

    1992-01-01

    Although early diagnosis of urinary tract infection is important, the radiologic evaluation is still controversial because of the low sensitivity and the lack of cost-effectiveness. This study was carried out to evaluate the clinical utility of high resolution triple head 99m Tc-DMSA SPECT imaging in urinary tract infection. We prospectively performed 99m Tc-DMSA planar and SPECT imaging, ultrasound of kidney (US), intravenous pyelography (IVP) and voiding cystourethrography (VCU) in all 60 adult patients with UTI [26 with first episode of acute pyelonephritis (APN), 22 with recurrent APN, and 12 persistent asymptomatic pyuria] and 25 normal persons. To assess reversibility of the renal cortical defect (RCD), 99m Tc-DMSA SPECT was repeated 1 to 8 months later in those patients with abnormal initial findings. Overall detection rate of 99m Tc-DMSA SPECT imaging was 83% (50/60), but planar, US, IVP and VCU showed abnormal findings in 68%, 28%, 32% and 13%, respectively. 25 out of 27 patients with normal or single RCD were all normal in other radiological studies. Only two patients showed vesicoureteral reflux (VUR) on VCU (grade I) and mild hydronephrosis on IVP. But, high proportion of those with multiple RCD showed abnormal findings on US (17/33), IVP (18/33), and VCU (7/33): 67% in any of these 3 studies. Especially, 3 out 7 patients with VUR showed multiple RCD on 99m Tc-DMSA SPECT without any abnormality on IVP or US. 25 normal persons showed normal findings in all studies except one false positive finding on 99m Tc-DMSA SPECT imaging. Follow-up 99m Tc-DMSA SPECT was done in 28 patients (13 with single RCD, 15 with multiple RCD). All 13 patients with single RCD showed improvement. Those with multiple RCD presented improvement in 4, no change in 10, and aggravation in 1 on follow-up studies. With these results, we conclude: 1) 99m Tc-DMSA SPECT imaging is superior to planar imaging, US, IVP or VCU in detection of renal lesion in urinary tract infection. 99m Tc-DMSA

  1. Physicochemical and biological study of a renal scintigraphy agent: the DMSA - 99mTc complex

    International Nuclear Information System (INIS)

    Laroche, Dominique

    1979-01-01

    This research thesis deals with the study of the dimercaptosuccinic acid (DMSA) marked with 99m Tc, a recently developed scintigraphy agent used for the kidney isotopic exploration. The author notably studied the relationships between the physicochemical properties of solutions of dimercaptosuccinic acid marked with 99m Tc and the biological distribution of 99m Tc in order to reach a better understanding of the biological mechanism which results in technetium fixation to the kidney

  2. sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

    Energy Technology Data Exchange (ETDEWEB)

    Hosokawa, S; Daijo, K; Okabe, T; Kawamura, J; Hara, A [Kyoto Univ. (Japan). Hospital

    1979-08-01

    Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1.

  3. sup(99m)Tc-DMSA renal scintigraphy in renal failure due to various renal diseases

    International Nuclear Information System (INIS)

    Hosokawa, Shin-ichi; Daijo, Kazuyuki; Okabe, Tatsushiro; Kawamura, Juichi; Hara, Akira

    1979-01-01

    Renal contours in renal failure were studied by means of sup(99m)Tc-dimercaptosuccinic acid (DMSA) renoscintigraphy. Renal cortical images were obtained even in renal failure cases. Causes of renal failure were chronic glomerulonephritis in 7, bilateral renal tuberculosis in 2, chronic pyelonephritis in 3, bilateral renal calculi in 3, diabetic nephropathy in 2, polycystic kidney disease in 2 and stomach cancer in 1. (author)

  4. Uncomplicated duplex kidney and DMSA scintigraphy in children with urinary tract infection

    Energy Technology Data Exchange (ETDEWEB)

    Stokland, Eira [The Sahlgrenska Academy at Goeteborg University, Department of Paediatric Radiology, Goeteborg (Sweden); The Queen Silvia Children' s Hospital, Department of Paediatric Radiology, Goeteborg (Sweden); Jodal, Ulf; Swerkersson, Svante; Hansson, Sverker [The Sahlgrenska Academy at Goeteborg University, Department of Paediatrics, Goeteborg (Sweden); Sixt, Rune [The Sahlgrenska Academy at Goeteborg University, Department of Paediatric Clinical Physiology, Goeteborg (Sweden)

    2007-08-15

    Renal duplication is the most common malformation of the urinary tract and is frequently seen among children with urinary tract infection (UTI). To evaluate problems in the interpretation of dimercaptosuccinic acid (DMSA) scintigraphy and to establish the range of relative function in uncomplicated unilateral duplication. Retrospective analysis of 303 children less than 2 years of age with first time non-obstructive urinary tract infection investigated by both urography and DMSA scintigraphy. At DMSA scintigraphy, renal lesions and/or relative function below 45% was considered abnormal. Urography was used as reference for the diagnosis of duplication. Duplex kidneys were found in 22 of 303 patients (7%). Of the 16 children with unilateral duplication, 10 had bilaterally undamaged kidneys with a range of relative function varying between 51% and 57% in the duplex kidney. In two of the children with unilateral duplication the imaging results were discordant. There was risk of underdiagnosis as well as overdiagnosis of renal damage at scintigraphy. Although it is important to be aware of this risk, the rate of misinterpretation was low. A range of 51% to 57% can be used as the limit for normality of the relative function of a unilateral duplex kidney. (orig.)

  5. Uncomplicated duplex kidney and DMSA scintigraphy in children with urinary tract infection

    International Nuclear Information System (INIS)

    Stokland, Eira; Jodal, Ulf; Swerkersson, Svante; Hansson, Sverker; Sixt, Rune

    2007-01-01

    Renal duplication is the most common malformation of the urinary tract and is frequently seen among children with urinary tract infection (UTI). To evaluate problems in the interpretation of dimercaptosuccinic acid (DMSA) scintigraphy and to establish the range of relative function in uncomplicated unilateral duplication. Retrospective analysis of 303 children less than 2 years of age with first time non-obstructive urinary tract infection investigated by both urography and DMSA scintigraphy. At DMSA scintigraphy, renal lesions and/or relative function below 45% was considered abnormal. Urography was used as reference for the diagnosis of duplication. Duplex kidneys were found in 22 of 303 patients (7%). Of the 16 children with unilateral duplication, 10 had bilaterally undamaged kidneys with a range of relative function varying between 51% and 57% in the duplex kidney. In two of the children with unilateral duplication the imaging results were discordant. There was risk of underdiagnosis as well as overdiagnosis of renal damage at scintigraphy. Although it is important to be aware of this risk, the rate of misinterpretation was low. A range of 51% to 57% can be used as the limit for normality of the relative function of a unilateral duplex kidney. (orig.)

  6. Surface characteristics of PLA and PLGA films

    Energy Technology Data Exchange (ETDEWEB)

    Paragkumar N, Thanki [Laboratoire de Chimie-Physique Macromoleculaire (LCPM), UMR CNRS-INPL 7568, Groupe ENSIC, 1 rue Grandville, B.P. 20451, 54001 Nancy Cedex (France); Edith, Dellacherie [Laboratoire de Chimie-Physique Macromoleculaire (LCPM), UMR CNRS-INPL 7568, Groupe ENSIC, 1 rue Grandville, B.P. 20451, 54001 Nancy Cedex (France); Six, Jean-Luc [Laboratoire de Chimie-Physique Macromoleculaire (LCPM), UMR CNRS-INPL 7568, Groupe ENSIC, 1 rue Grandville, B.P. 20451, 54001 Nancy Cedex (France)]. E-mail: Jean-Luc.Six@ensic.inpl-nancy.fr

    2006-12-30

    Surface segregation and restructuring in polylactides (poly(D,L-lactide) and poly(L-lactide)) and poly(D,L-lactide-co-glycolide) (PLGA) films of various thicknesses were investigated using both attenuated total reflection FTIR (ATR-FTIR) and contact angle relaxation measurements. In case of poly(D,L-lactide) (DLPLA), it was observed that the surface segregation and the surface restructuring of methyl side groups are influenced by the polymer film thickness. This result has been confirmed by X-ray photoelectron spectroscopy (XPS). In the same way, PLGA thick films were also characterized by an extensive surface segregation of methyl side groups. Finally, surface restructuring was investigated by dynamic contact angle measurements and it was observed when film surface comes into contact with water. In parallel, we also found that poly(L-lactide) (PLLA) thin and clear films with thickness {approx}15 {mu}m undergo conformational changes on the surface upon solvent treatment with certain solvents. The solvent treated surface of PLLA becomes hazy and milky white and its hydrophobicity increases compared to untreated surface. FTIR spectroscopic analysis indicated that polymer chains at the surface undergo certain conformational changes upon solvent treatment. These changes are identified as the restricted motions of C-O-C segments and more intense and specific vibrations of methyl side groups. During solvent treatment, the change in water contact angle and FTIR spectrum of PLLA is well correlated.

  7. Calcium phosphate cement scaffolds with PLGA fibers.

    Science.gov (United States)

    Vasconcellos, Letícia Araújo; dos Santos, Luís Alberto

    2013-04-01

    The use of calcium phosphate-based biomaterials has revolutionized current orthopedics and dentistry in repairing damaged parts of the skeletal system. Among those biomaterials, the cement made of hydraulic grip calcium phosphate has attracted great interest due to its biocompatibility and hardening "in situ". However, these cements have low mechanical strength compared with the bones of the human body. In the present work, we have studied the attainment of calcium phosphate cement powders and their addition to poly (co-glycolide) (PLGA) fibers to increase mechanical properties of those cements. We have used a new method that obtains fibers by dripping different reagents. PLGA fibers were frozen after lyophilized. With this new method, which was patented, it was possible to obtain fibers and reinforcing matrix which furthered the increase of mechanical properties, thus allowing the attainment of more resistant materials. The obtained materials were used in the construction of composites and scaffolds for tissue growth, keeping a higher mechanical integrity. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Thiolated Chitosan Masked Polymeric Microspheres with Incorporated Mesocellular Silica Foam (MCF for Intranasal Delivery of Paliperidone

    Directory of Open Access Journals (Sweden)

    Stavroula Nanaki

    2017-11-01

    Full Text Available In this study, mesocellular silica foam (MCF was used to encapsulate paliperidone, an antipsychotic drug used in patients suffering from bipolar disorder. MCF with the drug adsorbed was further encapsulated into poly(lactic acid (PLA and poly(lactide-co-glycolide (PLGA 75/25 w/w microspheres and these have been coated with thiolated chitosan. As found by TEM analysis, thiolated chitosan formed a thin layer on the polymeric microspheres’ surface and was used in order to enhance their mucoadhesiveness. These microspheres aimed at the intranasal delivery of paliperidone. The DSC and XRD studies showed that paliperidone was encapsulated in amorphous form inside the MCF silica and for this reason its dissolution profile was enhanced compared to the neat drug. In coated microspheres, thiolated chitosan reduced the initial burst effect of the paliperidone dissolution profile and in all cases sustained release formulations have been prepared. The release mechanism was also theoretically studied and three kinetic models were proposed and successfully fitted for a dissolution profile of prepared formulations to be found.

  9. Assessment of 99mTc-DMSA renoscintigraphy and uptake compared with creatinine clearance in rats with drug-induced nephrotoxicity, 1

    International Nuclear Information System (INIS)

    Yamada, Masafumi

    1991-01-01

    For evaluation of technetium-99m dimercaptosuccinic acid ( 99m Tc-DMSA) renal uptake as an absolute renal function, 99m Tc-DMSA uptake was compared with endogenous creatinine clearance (Ccr) in gentamicin-induced nephrotoxicity. Gentamicin (40 mg/kg/day) was given subcutaneously to male Wistar rats for periods of 3, 6, 9 and 12 days. On the next day, the renoscintigraphy was performed 2 hours following intravenous injection of 99m Tc-DMSA and Ccr was measured. On the 7th day, 99m Tc-DMSA uptake was significantly lower in the treated rats than that in control (32.27±0.92 vs 39.84±2.24%; p 99m Tc-DMSA uptake was measured and the histological examination was done. On the 4th day, 99m Tc-DMSA uptake was significantly lower than that on the 1st day (32.32±3.00 vs 38.91±1.95%; p 99m Tc-DMSA uptake reduces earlier than Ccr in gentamicin-induced nephrotoxicity and 99m Tc-DMSA uptake is a reliable indicator in the evaluation of a renal function in drug-induced nephrotoxicity. (author)

  10. Assessment of 99mTc-DMSA renoscintigraphy and uptake compared with creatinine clearance in rats with drug-induced nephrotoxicity, 2

    International Nuclear Information System (INIS)

    Yamada, Masafumi

    1991-01-01

    For evaluation of technetium-99m dimercaptosuccinic acid ( 99m Tc-DMSA) renal uptake as an absolute renal function, 99m Tc-DMSA uptake was compared with endogenous creatinine clearance (Ccr) in cisplatin-induced nephrotoxicity. At first, male Wistar rats were given intraperitoneally 1.8 mg/kg/day of cisplatin for periods of 3, 5, 7 and 9 days. On the next day, 99m Tc-DMSA uptake and Ccr were measured. Ccr of 5-day treated group was significantly lower than that of control (0.13±0.10 vs 0.34±0.05 ml/min/100 g; p 99m Tc-DMSA uptake did not change. 99m Tc-DMSA uptake of 7-day treated group was significantly lower than that of control (28.57±7.23 vs 39.84±2.23%; p 99m Tc-DMSA uptake was lower than that of control on the 8th, 11th and 15th day (32.40±3.86, 32.56±1.19, 35.21±2.97 vs 39.84±2.23%, respectively; p 99m Tc-DMSA uptake and Ccr was observed in the cisplatin-induced nephrotoxicity. 99m Tc-DMSA uptake was suggested to be a reliable indicator of a renal function in a different way from Ccr. (author)

  11. Critical aspects in the determination of the antifouling compound dichlofluanid and its metabolite DMSA (N,N-dimethyl-N′-phenylsulfamide) in seawater and marine sediments

    NARCIS (Netherlands)

    Schouten, A.; Mol, H.; Hamwijk, C.; Ravensberg, J.C.; Schmidt, K.; Kugler, M.

    2005-01-01

    A straightforward method based on GC-MS was developed to determine the booster biocide dichlofluanid and its metabolite DMSA in sediment and water. Special attention was paid to conservation of samples, conversion of dichlofluanid to DMSA during analysis and the effect dichlofluanid-containing paint

  12. Bone morphogenetic protein-2 loaded poly(D,L-lactide-co-glycolide microspheres enhance osteogenic potential of gelatin/hydroxyapatite/β-tricalcium phosphate cryogel composite for alveolar ridge augmentation

    Directory of Open Access Journals (Sweden)

    Hao-Chieh Chang

    2017-12-01

    Full Text Available Background/Purpose: Sufficient bony support is essential to ensure the success of dental implant osseointegration. However, the reconstruction of vertical ridge deficiencies is still a major challenge for dental implants. This study introduced a novel treatment strategy by infusing poly(D,L-lactide-co-glycolide (PLGA microspheres encapsulating bone morphogenetic protein-2 (BMP-2 within a gelatin/hydroxyapatite/β-tricalcium phosphate (gelatin/HA/β-TCP cryogel composite to facilitate supra-alveolar ridge augmentation. Methods: The gelatin scaffold was crosslinked using cryogel technique, and HA/β-TCP particles were mechanically entrapped to form the gelatin/HA/β-TCP composite. Co-axial electrohydrodynamic atomization technology was used to fabricate PLGA microspheres encapsulating BMP-2. The composites of gelatin/HA/β-TCP alone, with infusion of BMP-2 solution (BMPi or microspheres (BMPm, were fixed on rat mandibles using a titanium mini-implant for 4 weeks, and the therapeutic efficiency was evaluated by micro-computed tomography, bone fluorochrome, and histology. Results: The gelatin/HA/β-TCP composite was homogenously porous, and BMP-2 was sustained release from the microspheres without initial burst release. Ridge augmentation was noted in all specimens treated with the gelatin/HA/β-TCP composite, and greater bone deposition ratio were noted in Groups BMPi and BMPm. Compared with Group BMPi, specimens in Group BMPm showed significantly greater early osteogenesis and evident osseointegration in the supra-alveolar level. Conclusion: BMP-2 loaded PLGA microspheres effectively promoted osteogenic potential of the gelatin/HA/β-TCP composite and facilitated supra-alveolar ridge augmentation in vivo. Keywords: bone morphogenetic protein-2, bone regeneration, dental implant, tissue engineering, tissue scaffolds

  13. Comparison of morphology and mechanical properties of PLGA bioscaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Leung, L; Chan, C; Baek, S; Naguib, Hani [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King' s College Road, Toronto, Ontario, M5S 3G8 (Canada)], E-mail: naguib@mie.utoronto.ca

    2008-06-01

    In this study, bioscaffolds using poly(DL-lactide-co-glycolide) acid (PLGA) were fabricated and studied. The gas foaming/salt leaching technique in a batch foaming setup was employed, and the effects of material composition of PLGA on the morphology and mechanical properties using this process were investigated. Two material compositions of PLGA 50/50 and 85/15 were used, and characterization of scaffolds fabricated with these materials showed that a lower relative density can be achieved with an increasing poly(DL-lactide) acid (PDLLA) content; however, higher open-cell porosity was obtained with lower PDLLA content. Furthermore, the effect of PLGA composition on modulus of the scaffolds was minor.

  14. Permeation of PLGA nanoparticles across different in vitro models

    CSIR Research Space (South Africa)

    Nkabinde, LA

    2012-07-01

    Full Text Available of drug candidates when formulated as nanoparticles. PLGA nanoparticles were prepared by means of a double emulsion solvent evaporation technique and evaluated in terms of size, encapsulation efficiency, surface charge, isoniazid release and in vitro...

  15. Gastroretentive Floating Microspheres of Silymarin: Preparation and ...

    African Journals Online (AJOL)

    Methods: Cellulose microspheres – formulated with hydroxylpropyl methylcellulose (HPMC) and ethyl cellulose (EC) – and Eudragit microspheres – formulated with Eudragit® S 100 (ES) and Eudragit® RL (ERL) - were prepared by an emulsion-solvent evaporation method. The floating microspheres were evaluated for flow ...

  16. Diagnostic usefulness of technetium-99m (V) DMSA scintigraphy in cases of soft tissue tumors; In comparison with that of Ga-67 citrate scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hisataka; Kotoura, Yoshihiko; Hanbara, Harumi; Hosono, Makoto; Yamamuro, Takao; Konishi, Junji (Kyoto Univ. (Japan). Faculty of Medicine)

    1994-05-01

    Technetium-99m (V) DMSA scintigraphy was performed in 76 patients with pathologically confirmed soft tissue diseases. In 56 patients, gallium-67 citrate scintigraphy was performed within two weeks after technetium-99m (V) DMSA scintigraphy. Significant uptake of technetium-99m (V) DMSA was found in all cases of sarcoma, metastatic carcinoma, progressive benignancy (extra-abdominal desmoid etc.) and granulomatous lesions, but was not found in cases of benign, solid tumors in the soft tissue (leiomyoma, neurinoma, lipoma etc.). In conclusion, it is not necessary to treat patients with soft tissue tumors in which technetium-99m (V) DMSA did not accumulate. Therefore, it can be stated that technetium-99m (V) DMSA scintigraphy is useful for the screening of malignant tumors. (author).

  17. 99mTc-DMSA complex preparation. The effect of pH and tin(II) chloride amount on reaction

    International Nuclear Information System (INIS)

    Benkovsky, I.; Stanik, R.

    2010-01-01

    Labelling of meso-2,3-dimercaptosuccinic acid (DMSA) with technetium-99m was reinvestigated. Dependence of the 99m Tc-DMSA complex formation on the molar ratio of DMSA:reducing agent (SnCl 2 · 2H 2 O) and pH was studied. Five different types of 99m Tc-DMSA complexes were determined. Especially three different complexes were established in the clinically used and prepared DMSA kit labelled with 99m Tc under alkaline condition. This radiopharmaceutical is used as imaging agent of the primary medullary carcinoma in the thyroid gland and different metastasis types. The existence of all complexes was observed by paper chromatography, paper electrophoresis and high performance liquid chromatography. (author)

  18. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    Science.gov (United States)

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Burboa, María G.; Taboada, Pablo; Juárez, Josué; Valdez, Miguel A.

    2015-09-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air-water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction.

  19. Synthesis and characterization of magnetite/PLGA/chitosan nanoparticles

    International Nuclear Information System (INIS)

    Ibarra, Jaime; Melendres, Julio; Almada, Mario; Juárez, Josué; Valdez, Miguel A; Burboa, María G; Taboada, Pablo

    2015-01-01

    In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air–water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction. (paper)

  20. Correlation between differential renal uptake of 99mTc-MAG3 and 99mTc-DMSA

    International Nuclear Information System (INIS)

    Obaldo, J.M.; Gruenwald, F.; Menzel, C.; Biersack, H.J.

    1994-01-01

    We reviewed the quantitative indices obtained from sequential 99m Tc-MAG3 and 99m Tc-DMSA imaging studies performed in 134 patients with a variety of renal disorders in order to determine the correlation between the measured differential renal function using these two agents. Overall correlation was high with r=.86 and the derived regression equation was R.F. DMSA =8.2+0.84 (R.F. MAG3 ), where F.F. is the relative function. Highly divergent values for differential function were obtained however in some subjects. Patients with renal obstructive disorders had a correlation coefficient of.81 which was lower than those with nonobstructive pathologies (r=.95). Although relative kidney function measured using 99m Tc-MAG3 and 99m Tc-DMSA correlate significantly, certain patients such as those with renal obstruction may necessitate quantitation using different renal parameters. (orig.) [de

  1. Potential place of {sup 99m}Tc-DMSA scintigraphy in the management of children with urinary tract infection; Stellenwert der {sup 99m}Tc-DMSA-Szintigrafie bei der Behandlung von Kindern mit Harnwegsinfektionen

    Energy Technology Data Exchange (ETDEWEB)

    Piepsz, A. [Univ. Hospital St Pierre, Dept. Radioisotopes, Brussels (Belgium)

    2010-09-15

    Cortical {sup 99m}Tc DMSA scintigraphy is accepted as a highly sensitive technique for the detection of regional lesions. It reflects accurately the histological changes and the interobserver reproducibility in reporting is high. Potential technical pitfalls should be recognized, such as the normal variants and the difficulty to differentiate acute lesions from permanent ones, or acquired lesions from congenital ones. Although DMSA scintgraphy seems to play a minor role in the traditional approach of urinary tract infection, recent studies suggest that this examination might influence the treatment of the acute phase, the indication of chemoprophylaxis and of micturating cystography, as well as the duration of follow-up. (orig.)

  2. Antimicrobial Properties and Cytocompatibility of PLGA/Ag Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mariangela Scavone

    2016-01-01

    Full Text Available The purpose of this study was to investigate the antimicrobial properties of multifunctional nanocomposites based on poly(dl-Lactide-co-Glycolide (PLGA and increasing concentration of silver (Ag nanoparticles and their effects on cell viability for biomedical applications. PLGA nanocomposite films, produced by solvent casting with 1 wt%, 3 wt% and 7 wt% of Ag nanoparticles were investigated and surface properties were characterized by atomic force microscopy and contact angle measurements. Antibacterial tests were performed using an Escherichia coli RB and Staphylococcus aureus 8325-4 strains. The cell viability and morphology were performed with a murine fibroblast cell line (L929 and a human osteosarcoma cell line (SAOS-2 by cell viability assay and electron microscopy observations. Matrix protein secretion and deposition were also quantified by enzyme-linked immunosorbent assay (ELISA. The results suggest that the PLGA film morphology can be modified introducing a small percentage of silver nanoparticles, which induce the onset of porous round-like microstructures and also affect the wettability. The PLGA/Ag films having silver nanoparticles of more than 3 wt% showed antibacterial effects against E. coli and S. aureus. Furthermore, silver-containing PLGA films displayed also a good cytocompatibility when assayed with L929 and SAOS-2 cells; indicating the PLGA/3Ag nanocomposite film as a promising candidate for tissue engineering applications.

  3. Renal SPECT with {sup 99m} Tc-Dmsa. Reorientation and processing; SPECT renal con {sup 99m} Tc-Dmsa. Reorientacion y procesamiento

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.L.; Perera, A.; Fraxedas, R. [Centro de InvestigacionesClinicas 34 no.4501 e/45 y 47 Kohly, Playa C. Habana (Cuba)

    1998-12-31

    For the study of different renal affections with repercussion in the parenchyma is widely used the plane gammagraphy wit {sup 99m} Tc-Dmsa though not in the same way the SPECT technique. In general, the different inclination and orientation of the longitudinal axes of both kidneys in the patients entail aid to high variability in the detection of the different types of defects which leads to a possible mistaken diagnostic. With a view to this,it was developed in our centre a methodology for the automated reorientation of the different renal volumes obtained by SPECT and its posterior processing, obtaining as result a software with a high grade of independence from the operator. In this way, it is obtained a procedure standardization and so it let us with major rigor to realize evolutive studies of the patients. (Author)

  4. Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin.

    Directory of Open Access Journals (Sweden)

    Chunmei Qi

    Full Text Available Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA modified ultra-small super paramagnetic iron oxide (USPIO was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI.Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30. Group A with atherosclerosis plaque (n = 10 were controls. VP was established in groups B (n = 10 and C (n = 10 using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured.DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P <0.05.After successfully establishing a VP model in rabbits, DMSA-USPIO was used to enhance MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels.

  5. Development of a single-dose recombinant CAMP factor entrapping poly(lactide-co-glycolide) microspheres-based vaccine against Streptococcus agalactiae.

    Science.gov (United States)

    Liu, Gang; Yin, Jinhua; Barkema, Herman W; Chen, Liben; Shahid, Muhammad; Szenci, Otto; De Buck, Jeroen; Kastelic, John P; Han, Bo

    2017-03-01

    Streptococcus agalactiae is an important contagious bovine mastitis pathogen. Although it is well controlled and even eradicated in most Northern European and North American dairy herds, the prevalence of this pathogen remains very high in China. However, research on development of a vaccine against S. agalactiae mastitis is scarce. The aims of the present study were to: (1) develop a single-dose vaccine against S. agalactiae based on poly(lactic-co-glycolic acid) (PLGA) microspheres (MS) encapsulated CAMP factor, a conserved virulent protein encoded by S. agalactiae's cfb gene; and (2) evaluate its immunogenicity and protective efficacy in a mouse model. The cfb gene was cloned and expressed in a recombinant Escherichia coli strain Trans1-T1. The CAMP factor was tested to determine a safe dose range and then encapsulated in MS of PLGA (50:50) to assess its release pattern in vitro and immune reaction in vivo. Furthermore, a mouse model and a histopathological assay were developed to evaluate bacterial burden and vaccine efficacy. In the low dosage range (S. agalactiae challenge. Additionally, no pathological lesions were detected in the vaccinated group. Therefore, PLGA-CAMP conferred protective efficacy against S. agalactiae in our mouse model, indicating its potential as a vaccine against S. agalactiae mastitis. Furthermore, the slow-release kinetics of PLGA MS warranted optimism for development of a single-dose vaccine. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  6. Temperature influence in crystallinity of polymer microspheres

    International Nuclear Information System (INIS)

    Rezende, Cristiane de P.; Novack, Katia M.

    2011-01-01

    Drug delivery technology is evolving through the creation of new techniques of drug delivery effectively. The new methods used in drugs administration are based in microencapsulation process. Microsphere encapsulation modifies drug delivery bringing benefits and efficiency. In this work has been evaluated the influence of temperature in microspheres preparation. Microspheres were obtained by PMMA-co-PEG (COP) copolymer with indomethacin inserted in polymer matrix. Samples were characterized by SEM, DSC and XRD. SEM micrographs confirmed the formation of different sizes of microspheres and it was verified that higher temperatures make more crystalline microspheres. (author)

  7. Potential place of 99mTc-DMSA scintigraphy in the management of children with urinary tract infection

    International Nuclear Information System (INIS)

    Piepsz, A.

    2010-01-01

    Cortical 99m Tc DMSA scintigraphy is accepted as a highly sensitive technique for the detection of regional lesions. It reflects accurately the histological changes and the interobserver reproducibility in reporting is high. Potential technical pitfalls should be recognized, such as the normal variants and the difficulty to differentiate acute lesions from permanent ones, or acquired lesions from congenital ones. Although DMSA scintgraphy seems to play a minor role in the traditional approach of urinary tract infection, recent studies suggest that this examination might influence the treatment of the acute phase, the indication of chemoprophylaxis and of micturating cystography, as well as the duration of follow-up. (orig.)

  8. Studies on 99mTc-DMSA samples: some results concerning stability in time

    International Nuclear Information System (INIS)

    Metello, L.F.; Cunha, L.; Veiga, J.; Gomes, C.; Botelho, M.F.

    2002-01-01

    Aim: It has been decided to study the stability period of the 99mTc-DMSA after the advent of unclear situations, where this radiopharmaceutical was administered in a distant moment related to the preparation time, and also because of some rare imagiological findings, not exactly predictable and/or compatible when considering their relations with the specific clinical environment, even if it was happening clearly inside the stability time given as reference by the producer of the radiopharmaceutical. The first thing to be found was that the concerned information in current bibliography is quite uncertain, some authors defending kits stability in time from half hour till six hours and with most authors making reference to half hour, which clearly and obviously contradicts the literature furnished with the kits, that usually refers stability periods between four and six hours. Methods and Conclusions: As developed methodology, it was decided to establish and use a Quality Control Program, consisting on running in parallel the three specific methods indicated to study this radiopharmaceutical properties and purity, over the time, starting on the fifth minute after completion of the kits and going until a maximum of eight hours after this moment, having always previously studied the radiochemical purity of the 99mTc-eluate being used. In the development of this study, we used several lyophilised formulations, from distinct producers. We easily arrived to the conclusion that, if the free pertechnetate and the colloidal technetium remains more or less stable on his relative amount over the time, the relative amounts concerning the DMSA III (oxidation state III) and the DMSA V (oxidation state V) are quite distinct from the expected and described on the literature, putting once again in evidence the urgent need to implement Quality Control as a indispensable part of the each day routine on a Nuclear Medicine Department

  9. Formulation, radiopharmaceutical kinetics and dosimetry of the 188Re(V)-DMSA complex

    International Nuclear Information System (INIS)

    Garcia S, L.; Ferro F, G.; Murphy, C.A. de; Pedraza L, M.; Azorin N, J.

    1999-01-01

    It was developed through experimental design (ANOVA), a formulation to prepare the 188 Re(V)-Dmsa complex. Likewise, there were realized studies of radiopharmaceutical kinetics and internal dosimetry in animals, its normal and with induced tumors, considering an open bi compartmental model using the MIRD methodology. The 188 Re(V)-Dmsa complex was obtained with a radiochemical purity greater than 95% incubating 30 min at 90 Centigrade under the following formulation: [SnCl 2 ] = 1.4 mg/ml, [ascorbic acid] = 0.5 mg/ml, p H = 2.0 - 3.0. The stability test of the formulation, shows that after 48 h of its preparation, does not produce radiolytic degradation neither chemical decomposition. The radiopharmaceutical kinetics data show an average residence time 7.2h, velocity constant α = 0.6508h -1 and β = 0.1046 h -1 with an apparent distribution volume 6.9 l. The main elimination via was renal and it was observed osseous caption with an accumulated activity 522.049 ± 62 MBq h (residence time 14.1094 ± 1.69h). In according with the dosimetric calculations, by each 37 MBq injected, the equivalent dose at the tumor was 9.67± 0.33 Sv/g, for an effective dose 0.292 ± 0.0017 mSv/MBq. The images obtained in the gamma camera of the mice with induced tumors, show that do not have significant accumulation in the metabolic organs. The caption in bone and in tumors induced of the 188 Re(V)-Dmsa complex, show its potential for be used as a palliative agent for pain in patients with osseous metastasis and in the treatment of tumors of soft tissue. (Author)

  10. Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

    DEFF Research Database (Denmark)

    Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Nasri-Nasrabadi, Bijan

    2016-01-01

    Poly(lactic-co-glycolic.acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical...... the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nano fibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss...... properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results...

  11. SPECT and 3D display quantitative evaluation in renal DMSA scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, M; Skouroliakou, K; Emmanouilides, I; Stratis, I [Univerisity of Athens, Department of Radiology and Department of Mathematics, Athens (Greece)

    1999-12-31

    The evaluation of cortical damage to the kidneys, especially in children, is currently performed by means of Tc99m-DMSA renal scan. The routine involves the acquisition of planar images and their qualitative and quantitative evaluation. Many studies have dealt with the possible advantage that SPECT could possess on qualitative criteria. This study attempts to quantitatively deal with the issue by the calculation of an index. The results exhibit a clear advantage of tomographic and 3D reconstructed images over the conventional planar ones. (authors) 14 refs., 3 figs., 1 tabs.

  12. Development and in vitro characterization of poly(lactide-co-glycolide microspheres loaded with an antibacterial natural drug for the treatment of long-term bacterial infections

    Directory of Open Access Journals (Sweden)

    Reinbold J

    2016-09-01

    Full Text Available Jochen Reinbold,1 Teresa Hierlemann,1 Helena Hinkel,1 Ingrid Müller,2 Martin E Maier,3 Tobias Weindl,4 Christian Schlensak,1 Hans Peter Wendel,1 Stefanie Krajewski1 1Department of Thoracic, Cardiac and Vascular Surgery, University Hospital Tuebingen, Tuebingen, 2Department of Pharmaceutical Engineering, Albstadt-Sigmaringen University, Sigmaringen, 3Institute of Organic Chemistry, University Tuebingen, Tuebingen, 4Aimecs GmbH, Pfarrkirchen, Germany Abstract: Biodegradable polymers, especially poly(lactide-co-glycolide (PLGA, have good biocompatibility and toxicological properties. In combination with active ingredients, a specialized drug delivery system can be generated. The aim of the present study was to develop a drug delivery system consisting of PLGA microspheres loaded with the natural active ingredient totarol, which has several antimicrobial mechanisms. Totarol, isolated from the Podocarpus totara tree, was purified using column chromatography, and the eluate was checked for purity using thin layer chromatography. The spherically shaped microspheres with mean diameters of 147.21±3.45 µm and 131.14±3.69 µm (totarol-loaded and -unloaded microspheres, respectively were created using the single emulsion evaporation method. Furthermore, the encapsulation efficiency, in a range of 84.72%±6.68% to 92.36%±0.99%, was measured via UV/vis spectroscopy. In a 90-day in vitro drug release study, the release of totarol was investigated by UV/vis spectroscopy as well, showing a release of 53.76%. The toxicity on cells was determined using BJ fibroblasts or Human Embryonic Kidney cells and an 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay, which showed no influence on the cell growth. The minimal inhibitory concentration was ascertained. A totarol concentration between 64 µg/mL and 128 µg/mL was necessary to inhibit the bacterial growth over a period of 24 hours. Biofilm formation on the surface of totarol

  13. Microsphere-Based Scaffolds Carrying Opposing Gradients of Chondroitin Sulfate and Tricalcium Phosphate

    Directory of Open Access Journals (Sweden)

    Vineet eGupta

    2015-07-01

    Full Text Available Extracellular matrix (ECM components such as chondroitin sulfate (CS and tricalcium phosphate (TCP serve as raw materials and thus spatial patterning of these raw materials may be leveraged to mimic the smooth transition of physical, chemical and mechanical properties at the bone-cartilage interface. We hypothesized that encapsulation of opposing gradients of these raw materials in high molecular weight poly(D,L-lactic-co-glycolic acid (PLGA microsphere-based scaffolds would enhance differentiation of rat bone marrow stromal cells (rBMSCs. The raw material encapsulation altered the microstructure of the microspheres and also influenced the cellular morphology that depended on the type of material encapsulated. Moreover, the mechanical properties of the raw material encapsulating microsphere-based scaffolds initially relied on the composition of the scaffolds and later on were primarily governed by the degradation of the polymer phase and newly synthesized extracellular matrix by the seeded cells. Furthermore, raw materials had a mitogenic effect on the seeded cells and led to increased glycosaminoglycan (GAG, collagen, and calcium content. Interestingly, the initial effects of raw material encapsulation on a per-cell basis might have been overshadowed by medium-regulated environment that appeared to favor osteogenesis. However, it is to be noted that in vivo, differentiation of the cells would be governed by the surrounding native environment. Thus, the results of this study demonstrated the potential of the raw materials in facilitating neo-tissue synthesis in microsphere-based scaffolds and perhaps in combination with bioactive signals, these raw materials may be able to achieve intricate cell differentiation profiles required for regenerating the osteochondral interface.

  14. Continuous delivery of propranolol from liposomes-in-microspheres significantly inhibits infantile hemangioma growth

    Directory of Open Access Journals (Sweden)

    Guo XN

    2017-09-01

    Full Text Available Xiaonan Guo,1,* Xiaoshuang Zhu,1,* Dakan Liu,1 Yubin Gong,1 Jing Sun,2 Changxian Dong1 1Department of Hemangioma and Vascular Malformation, Henan Provincial People’s Hospital, Zhengzhou, People’s Republic of China; 2Department of Pharmacy, Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: To reduce the adverse effects and high frequency of administration of propranolol to treat infantile hemangioma, we first utilized propranolol-loaded liposomes-in-microsphere (PLIM as a novel topical release system to realize sustained release of propranolol.Methods: PLIM was developed from encapsulating propranolol-loaded liposomes (PLs in microspheres made of poly(lactic-co-glycolic acid-b-poly(ethylene glycol-b-poly(lactic-co-glycolic acid copolymers (PLGA-PEG-PLGA. The release profile of propranolol from PLIM was evaluated, and its biological activity was investigated in vitro using proliferation assays on hemangioma stem cells (HemSCs. Tumor inhibition was studied in nude mice bearing human subcutaneous infantile hemangioma.Results: The microspheres were of desired particle size (~77.8 µm and drug encapsulation efficiency (~23.9% and achieved sustained drug release for 40 days. PLIM exerted efficient inhibition of the proliferation of HemSCs and significantly reduced the expression of two angiogenesis factors (vascular endothelial growth factor-A [VEGF-A] and basic fibroblast growth factor [bFGF] in HemSCs. Notably, the therapeutic effect of PLIM in hemangioma was superior to that of propranolol and PL in vivo, as reflected by significantly reduced hemangioma volume, weight, and microvessel density. The mean hemangioma weight of the PLIM-treated group was significantly lower than that of other groups (saline =0.28 g, propranolol =0.21 g, PL =0.13 g, PLIM =0.03 g; PLIM vs saline: P<0.001, PLIM vs propranolol: P<0.001, PLIM vs PL: P<0.001. The mean microvessel density of

  15. The preparation for an instant kit of 99mTc(V) DMSA as a tumor-seeking imaging agent and animal experimentation

    International Nuclear Information System (INIS)

    Li Yunlong; Li Hongyu; Jing Hui; Guo Hongyuan; Liu Yingmei; Zhao Hui

    1997-10-01

    A method for preparing an instant kit of 99m Tc(V) DMSA was described. The effect of pH on labelling efficiency of the kit was investigated. 99m Tc(V) DMSA was characterized by TLC on silica-gel sheets, eluting with n-butanol: acetic acid: water = 3:2:3 (volume ratio). Radiochemical purity and stability of 99m Tc(V) DMSA in vitro were studied. The results clearly demonstrated that the yield of 99m Tc(V) DMSA was more than 95% at pH 8∼8.5 and the agent was stable in 3 h at room temperature. Effect of temperature, moisture and luminosity on the stability of the freeze-dried kit were considered. The biological distributions of 99m Tc(V) DMSA were measured in mice bearing tumor S180. The results indicated that during 1∼6 h after i.v. injection, 99m Tc(V) DMSA was highly up taken in tumor tissue, the ratios of tumor: muscle and tumor: bone were in the ranges of 1.4∼2.4 and 1.2∼1.8, respectively. This peculiarity indicated that 99m Tc(V) DMSA has tumor-seeking property and could be used as a tumor-seeking imaging agent. (9 refs., 11 tabs.)

  16. Microsphere-based gradient implants for osteochondral regeneration: a long-term study in sheep

    Science.gov (United States)

    Mohan, Neethu; Gupta, Vineet; Sridharan, Banu Priya; Mellott, Adam J; Easley, Jeremiah T; Palmer, Ross H; Galbraith, Richard A; Key, Vincent H; Berkland, Cory J; Detamore, Michael S

    2015-01-01

    Background: The microfracture technique for cartilage repair has limited ability to regenerate hyaline cartilage. Aim: The current study made a direct comparison between microfracture and an osteochondral approach with microsphere-based gradient plugs. Materials & methods: The PLGA-based scaffolds had opposing gradients of chondroitin sulfate and β-tricalcium phosphate. A 1-year repair study in sheep was conducted. Results: The repair tissues in the microfracture were mostly fibrous and had scattered fissures with degenerative changes. Cartilage regenerated with the gradient plugs had equal or superior mechanical properties; had lacunated cells and stable matrix as in hyaline cartilage. Conclusion: This first report of gradient scaffolds in a long-term, large animal, osteochondral defect demonstrated potential for equal or better cartilage repair than microfracture. PMID:26418471

  17. Preparation of biodegradable magnetic microspheres with poly(lactic acid)-coated magnetite

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hong; Saatchi, Katayoun [Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, 6T 1Z3 (Canada); Haefeli, Urs O. [Faculty of Pharmaceutical Sciences, University of British Columbia, 2146 East Mall, Vancouver, BC, V6T 1Z3 (Canada)], E-mail: uhafeli@interchange.ubc.ca

    2009-05-15

    Poly(lactic acid) (PLA)-coated magnetic nanoparticles were made using uncapped PLA with free carboxylate groups. The physical properties of these particles were compared to those of oleate-coated or oleate/sulphonate bilayer (W40) coated magnetic particles. Magnetic microspheres (MMS) with the matrix material poly(lactide-co-glycolide) (PLGA) or PLA were then formed by the emulsion solvent extraction method with encapsulation efficiencies of 40%, 83% and 96% for oleate, PLA and oleate/sulfonate-coated magnetic particles, respectively. MMS made from PLA-coated magnetite were hemocompatible and produced no hemolysis, whereas the other MMS were hemolytic above 0.3 mg/mL of blood.

  18. Preparation of biodegradable magnetic microspheres with poly(lactic acid)-coated magnetite

    International Nuclear Information System (INIS)

    Zhao Hong; Saatchi, Katayoun; Haefeli, Urs O.

    2009-01-01

    Poly(lactic acid) (PLA)-coated magnetic nanoparticles were made using uncapped PLA with free carboxylate groups. The physical properties of these particles were compared to those of oleate-coated or oleate/sulphonate bilayer (W40) coated magnetic particles. Magnetic microspheres (MMS) with the matrix material poly(lactide-co-glycolide) (PLGA) or PLA were then formed by the emulsion solvent extraction method with encapsulation efficiencies of 40%, 83% and 96% for oleate, PLA and oleate/sulfonate-coated magnetic particles, respectively. MMS made from PLA-coated magnetite were hemocompatible and produced no hemolysis, whereas the other MMS were hemolytic above 0.3 mg/mL of blood.

  19. Pre- and Post-operative cortical function of the kidney with staghorn calculi assessed by sup(99m)Tc-DMSA renal scintigraphy

    International Nuclear Information System (INIS)

    Kawamura, Juichi

    1982-01-01

    sup(99m)Tc-DMSA renal scintigraphy consisting of the cortical image and DMSA renal uptake was used to assess the pre- and post-operative renal function in 39 patients with staghorn calculi or complicated calculi occupying more than 2 major calices. Extended pyelolithotomy was performed on 14 patients, nephrolithotomy on 14 patients, pyelolithotomy combined with nephrotomy on 7 patients, and partial nephrectomy on 4 patients. Nine out of 14 patients who underwent pyelolithotomy and 4 out of 14 patients who underwent nephrolithotomy showed an increase or no change in the postoperative DMSA renal uptake in the diseased kidney. However, there was no increase in the postoperative DMSA renal uptake in the patients who underwent pyelolithotomy combined with nephrotomy or partial nephrectomy. Eight percent of the preoperative DMSA renal uptake in the diseased kidney seems to be the absolute level for predicting a postoperative recovery of the kidney function. The contralateral kidney function can affect the postoperative recovery of the function in the operative side. It seems to be hard to expect an increment in the DMSA renal uptake postoperatively when the ratio of DMSA renal uptake in the operative side to the total DMSA renal uptake is less than 20%. At least 6 months of the follow-up period is necessary for the evaluation of the kidney function in the operative side. DMSA renal scintigraphy is a useful modality to assess pre- and post-operative kidney function in nephrolithiasis from the point of both morphological and functional changes in the renal cortex. (author)

  20. An analysis of motion correction for 99Tcm DMSA renal imaging in paediatrics

    International Nuclear Information System (INIS)

    Meadows, A.; Hogg, P.

    2007-01-01

    Movement artefact during paediatric 99 Tc m DMSA renal imaging can reduce image quality and therefore render images non-diagnostic. This research assessed software used for the correction of movement artefact in children. The software comprised a count rate dependent dynamic acquisition with a 256 x 256 pixel frame-shift motion correction algorithm. A Williams' phantom was used to generate data during dynamic (experimental) and static (control) image acquisitions. During image acquisition, the Williams' phantom was moved to simulate seven typical paediatric patient movements; acquisitions also considered no movement (Gold Standard). Seven image data sets with motion artefact were corrected using the frame-shift software. The corrected, uncorrected, and static images were rated for quality by suitably qualified and experienced nuclear medicine professionals. The images were scored using an image quality assessment instrument, based on a Likert rating scale. Inferential statistics were applied to these data. The image quality ratings demonstrated a statistically significant (P 99 Tc m DMSA renal scans

  1. 99mTc-DMSA assessment of unilateral renal function: comparative study of two methods

    International Nuclear Information System (INIS)

    Llamas, J.M.; Torres, M.; Mallol, J.; Latre, J.M.; Martinez Paredes, M.; Carreras, J.L.

    1987-01-01

    Results obtained with two different methods of assessing unilateral renal function by measuring the percentage of relative uptake following the administration of a tracing dose of Tc 99m -DMSA are compared in a sample of 40 patients with various conditions. As a reference test, I 131 -hippurate 1'-2' relative uptake, corrected by normalized background and attenuation, was employed. Tc 99m -DMSA relative uptake was determined at 24 hours using the following methods: 1) Percentage of accumulated counts over each renal area in relation to the total, for two minutes, corrected by normalized background and attenuation. 2) Percentage of accumulated counts over each renal area in relation to the total, obtained from the geometrical mean value of accumulated counts in AP and PA projections. A correlation analysis between the two methods, and between these and the reference test, were performed. Good correlations among them (r=0,98 between double-image DMS and Hippurate; p<0,001 in all cases) were found. (author)

  2. An audit of RCP guidelines on DMSA scanning after urinary tract infection.

    Science.gov (United States)

    Deshpande, P V; Jones, K V

    2001-04-01

    To assess the outcome of imaging investigations carried out in children with urinary tract infection (UTI), to compare the investigations with national guidelines, and to assess the impact on management. Retrospective review of inpatients and outpatients, aged 0-12 years, referred to the University Hospital of Wales Healthcare Trust between February 1997 and January 1998 with UTI. All children without bacterial evidence of UTI and children previously investigated for antenatal urological anomalies, major congenital anomalies, or UTI were excluded. A total of 164 children (51 boys, 113 girls) were included. Thirteen of 56 infants (23%) and 82/108 older children (76%) were diagnosed at home over one year. The prevalence of dilatation on ultrasound was 8%, renal scarring on dimercaptosuccinic acid (DMSA) scan was 11%, and vesicoureteric reflux (VUR) was 34% when investigations were carried out following guidelines published by the Royal College of Physicians. In children aged 1-6 years, the prevalence of scarring was 1/54 (2%) in those treated at home and 6/18 (33%) in inpatients. The low yield of positive results and lack of evidence of impact on management indicate that DMSA scanning, with all the implications of isotope exposure, intravenous injection, staff time, psychological trauma, and expense, could be omitted in children over 1 year with first simple UTI not sufficiently ill to be admitted to hospital. The low rate of detection of UTI in primary care in infants may represent under diagnosis.

  3. Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Jae Baek Lee

    2015-01-01

    Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.

  4. HDL-mimetic PLGA nanoparticle to target atherosclerosis plaque macrophages.

    Science.gov (United States)

    Sanchez-Gaytan, Brenda L; Fay, Francois; Lobatto, Mark E; Tang, Jun; Ouimet, Mireille; Kim, YongTae; van der Staay, Susanne E M; van Rijs, Sarian M; Priem, Bram; Zhang, Liangfang; Fisher, Edward A; Moore, Kathryn J; Langer, Robert; Fayad, Zahi A; Mulder, Willem J M

    2015-03-18

    High-density lipoprotein (HDL) is a natural nanoparticle that exhibits an intrinsic affinity for atherosclerotic plaque macrophages. Its natural targeting capability as well as the option to incorporate lipophilic payloads, e.g., imaging or therapeutic components, in both the hydrophobic core and the phospholipid corona make the HDL platform an attractive nanocarrier. To realize controlled release properties, we developed a hybrid polymer/HDL nanoparticle composed of a lipid/apolipoprotein coating that encapsulates a poly(lactic-co-glycolic acid) (PLGA) core. This novel HDL-like nanoparticle (PLGA-HDL) displayed natural HDL characteristics, including preferential uptake by macrophages and a good cholesterol efflux capacity, combined with a typical PLGA nanoparticle slow release profile. In vivo studies carried out with an ApoE knockout mouse model of atherosclerosis showed clear accumulation of PLGA-HDL nanoparticles in atherosclerotic plaques, which colocalized with plaque macrophages. This biomimetic platform integrates the targeting capacity of HDL biomimetic nanoparticles with the characteristic versatility of PLGA-based nanocarriers.

  5. A method for estimating DMSA SPECT renal function for assessing the effect of percutaneous nephrolithotripsy on the treated pole

    International Nuclear Information System (INIS)

    AGUIAR, Pablo; RUIBAL, Álvaro; CORTÉS, Julia; PÉREZ-FENTES, Daniel; GARCÍA, Camilo; GARRIDO, Miguel

    2016-01-01

    The aim of this study was to develop a method for estimating DMSA SPECT renal function on each renal pole in order to evaluate the effect of percutaneous nephrolithotripsy by focusing the measurements on the region through which the percutaneous approach is performed. Twenty patients undergoing percutaneous nephrolithotripsy between November 2010 and June 2012 were included in this study. Both Planar and SPECT-DMSA studies were carried out before and after nephrolithotripsy. The effect of percutaneous nephrolithotripsy was evaluated by estimating the total renal function and the regional renal function of each renal pole. Despite PCNL has been previously reported as a minimally invasive technique, our results showed regional renal function decreases in the treated pole in most patients, affecting the total renal function in a few of them. A quantification method was used for estimating the SPECT DMSA renal function of the upper, inter polar and lower renal poles. Our results confirmed that total renal function was preserved after nephrolithotripsy. Nevertheless, the proposed method showed that the regional renal function of the treated pole decreased in most patients (15 of 20 patients), allowing us to find differences in patients who had not shown changes in the total renal function obtained from conventional quantification methods. In conclusion, a method for estimating the SPECT DMSA renal function focused on the treated pole enabled us to show for the first time that nephrolithotripsy can lead to a renal parenchymal damage restricted to the treated pole.

  6. Qualitative and quantitative evaluation of renal parenchymal damage by 99mTc-DMSA planar and SPECT scintigraphy

    International Nuclear Information System (INIS)

    Itoh, Kazuo; Yamashita, Tetsufumi; Tsukamoto, Eriko; Nonomura, Katsuya; Furudate, Masayori; Koyanagi, Tomohiko

    1995-01-01

    The initial 99m Tc-DMSA studies carried out over a four year period in 229 patients with various heterogenic causes of lower urinary tract abnormalities were reviewed. Anatomical damage to the renal parenchyma was graded by means of planar and SPECT studies into a six group classification proposed by Monsour et al.: grade 0 (normal), I (equivocal), II (single defect), III (more than 2 defects), IV (contracted or small) and V (no visualization). Parenchymal uptake of 99m Tc-DMSA was quantitated from planar images at 2 hours postinjection by a computer assisted gamma camera method. SPECT studies could enhance the pick-up rate for parenchymal uptake defects by a factor of 1.5 in comparison with planar imaging. The incidence of anatomical damage to the renal parenchyma increased with a high radiological grade for VUR, and renal uptake per injection dose of 99m Tc-DMSA by the individual kidney significantly decreased in grades III and IV of the anatomical classification. These data revealed that 99m Tc-DMSA planar is still useful for evaluating gross structural damage and for quantitative evaluation of the kidney with computer assistance. SPECT scintigraphy is more effective in disclosing anatomical damage to the renal parenchyma than planar, although it needs further discussion as to whether SPECT may increase sensitivity with minimal or no adverse affect on specificity. (author)

  7. Differentiation of pituitary adenomas from other sellar and parasellar tumors by {sup 99m}Tc(V)-DMSA scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Koji [Yokohama City Univ. (Japan). Medical Center; Suzuki, Shinichi; Yamamoto, Isao [Yokohama City Univ. (Japan). School of Medicine

    2003-04-01

    Pentavalent technetium-99m dimercaptosuccinic acid [{sup 99m}Tc(V)-DMSA] scintigraphy was evaluated for the differentiation of pituitary adenomas, especially non-functioning adenomas, from other sellar and parasellar lesions. Diffuse {sup 99m}Tc(V)-DMSA accumulation within the tumor was found in seven of seven non-functioning, three of four growth hormone-secreting, and seven of eight prolactin-secreting adenomas, but only partial accumulation in only two of 16 non-pituitary adenomas and normal pituitary glands. There were no significant relationship between tumor-to-background ratios and tumor size or serum hormone level. {sup 99m}Tc(V)-DMSA scintigraphy showed overall sensitivity of 81% (17/21 cases) for detecting pituitary adenomas, in particular 100% for non-functioning adenomas. {sup 99m}Tc(V)-DMSA may be useful for detecting pituitary adenomas, especially non-functioning adenomas, and for the differentiation of non-functioning pituitary adenomas from other sellar and parasellar lesions. (author)

  8. Validity of 99mTc-DMSA renal uptake by planar posterior-view method in children

    International Nuclear Information System (INIS)

    Tsukamoto, Eriko; Katoh, Chietsugu; Mochizuki, Takafumi; Shiga, Toru; Morita, Koichi; Tamaki, Nagara; Itoh, Kazuo

    1999-01-01

    Renal uptake 99m Tc-DMSA has been quantified by various methods. The aim of this study is to obtain a normal value for 99m Tc-DMSA renal uptake calculated by the posterior view method and age variation, and to assess its clinical validity. Scintigrams of 238 children (0-12 years) with 99m Tc-DMSA were reviewed. All the children had a clinical history of primary vesicoureteral reflux and/or neurogenic bladder, ureteral or urethral anomalies. Their kidneys were divided into two groups, ''normal'' and abnormal'' according to their scintigraphic findings and split renal functions. Percent renal uptake per injected dose (% RU) was quantitated from planar images at 2 hours after injection of an age-adjusted dose (26-95 MBq) of 99m Tc-DMSA. Calculated total % RU, individual % UR of the right and left kidneys (mean±sd) in patients with normal kidneys were 40.7±5.0%, 20.2±3.0%, 20.4±2.7%, respectively. There was no significant correlation between % RU and age (r=0.231). Longitudinal variation in the % RU in 9 patients ranged from 1.2% to 18%. Our conventional method for quantifying % RU is simple, practical and feasible in routine clinical practice, especially for children under follow up. (author)

  9. Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

    International Nuclear Information System (INIS)

    Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Nasri-Nasrabadi, Bijan; Ghaedi, Kamran; Salehi, Hossein; Dolatshahi-Pirouz, Alireza; Arpanaei, Ayyoob

    2016-01-01

    Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes. - Highlights: • PLGA-based random nanofibers embedded with mesoporous silica nanoparticles were fabricated using electrospinning method • Incorporation of gelatin and MSNPs into PLGA-based scaffolds increased the hydrophilicity of scaffold • Addition of nanoparticles also improved the tensile mechanical properties of scaffolds • Introduction of MSNPs led to improved cell attachment and proliferation

  10. Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties

    Energy Technology Data Exchange (ETDEWEB)

    Mehrasa, Mohammad [Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of); Asadollahi, Mohammad Ali, E-mail: ma.asadollahi@ast.ui.ac.ir [Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Nasri-Nasrabadi, Bijan [Department of Chemical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Ghaedi, Kamran [Department of Biology, Faculty of Science, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Salehi, Hossein [Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Dolatshahi-Pirouz, Alireza [DTU Nanotech, Center for Nanomedicine and Theranostics, Technical University of Denmark (DTU), DK-2800 Kgs. Lyngby (Denmark); Arpanaei, Ayyoob, E-mail: arpanaei@yahoo.com [Department of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran (Iran, Islamic Republic of)

    2016-09-01

    Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974 ± 68 nm for the pure PLGA scaffolds vs 832 ± 70, 764 ± 80, and 486 ± 64 for the PLGA/gelatin, PLGA/10 wt% MSNPs, and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes. - Highlights: • PLGA-based random nanofibers embedded with mesoporous silica nanoparticles were fabricated using electrospinning method • Incorporation of gelatin and MSNPs into PLGA-based scaffolds increased the hydrophilicity of scaffold • Addition of nanoparticles also improved the tensile mechanical properties of scaffolds • Introduction of MSNPs led to improved cell attachment and proliferation.

  11. Preparing microspheres of actinide nitrides from carbon containing oxide sols

    International Nuclear Information System (INIS)

    Triggiani, L.V.

    1975-01-01

    A process is given for preparing uranium nitride, uranium oxynitride, and uranium carboxynitride microspheres and the microspheres as compositions of matter. The microspheres are prepared from carbide sols by reduction and nitriding steps. (Official Gazette)

  12. Studies on the evaluation of renal function in urological renal disorders with 99mTc-DMSA renal uptake, 1

    International Nuclear Information System (INIS)

    Takeda, Masayuki

    1987-01-01

    The change of normal value of 99m Tc-dimercaptosuccinic acid (DMSA) renal uptake with age was investigated, and the correlation between total renal uptake of 99m Tc-DMSA and 24-hour endogenous creatinine clearance was studied in each age group separately. (1) 99m Tc-DMSA renal uptake was measured in 107 normal controls without renal or urinary tract diseases between 0 and 67 years old and normal values were analyzed in each age group. The normal value was highest in the age group of 0 ∼ 9 years old and was gradually decreased with age. Over 20 years old, the normal value hardly changed. (2) The lower limit of normal values of 99m Tc-DMSA renal uptake in each kidney was 19.62, 13.89, 13.18, 11.58, 12.00, 10.24 % in the age groups of 0 ∼ 9, 10 ∼ 19, 20 ∼ 29, 30 ∼ 39, 40 ∼ 49, 50 ∼ 59 years old, respectively. (3) Correlations between total renal uptake and 24-hour endogenous creatinine clearance were investigated in each age group in 248 patients between 0 and 79 years old. Positive linear correlations were found in the age groups of 0 ∼ 9, 10 ∼ 19, 20 ∼ 29, 30 ∼ 39, 40 ∼ 49, 50 ∼ 59, 60 ∼ 69, 70 ∼ 79 years old, and especially above 50 years old closer correlations were found. It is concluded that although 99m Tc-DMSA renal uptake is a useful method for renal function test through life, the change with age must be considered in the evaluation of its value. (author)

  13. Identifying Vulnerable Atherosclerotic Plaque in Rabbits Using DMSA-USPIO Enhanced Magnetic Resonance Imaging to Investigate the Effect of Atorvastatin

    Science.gov (United States)

    Li, Dongye; Wu, Weiheng; Gong, Lei; Li, Yong; Zhang, Qingdui; Zhang, Tao; Zhang, Chao; Zhang, Yu

    2015-01-01

    Background Rupture of an atherosclerotic plaque is the primary cause of acute cardiovascular and cerebrovascular syndromes. Early and non-invasive detection of vulnerable atherosclerotic plaques (VP) would be significant in preventing some aspects of these syndromes. As a new contrast agent, dimercaptosuccinic acid (DMSA) modified ultra-small super paramagnetic iron oxide (USPIO) was synthesized and used to identify VP and rupture plaque by magnetic resonance imaging (MRI). Methods Atherosclerosis was induced in male New Zealand White rabbits by feeding a high cholesterol diet (n = 30). Group A with atherosclerosis plaque (n = 10) were controls. VP was established in groups B (n = 10) and C (n = 10) using balloon-induced endothelial injury of the abdominal aorta. Adenovirus-carrying p53 genes were injected into the aortic segments rich in plaques after 8 weeks. Group C was treated with atorvastatin for 8 weeks. Sixteen weeks later, all rabbits underwent pharmacological triggering, and imaging were taken daily for 5 d after DMSA-USPIO infusion. At the first day and before being killed, serum MMP-9, sCD40L, and other lipid indicators were measured. Results DMSA-USPIO particles accumulated in VP and rupture plaques. Rupture plaques appeared as areas of hyper-intensity on DMSA-USPIO enhanced MRI, especially T2*-weighted sequences, with a signal strength peaking at 96 h. The group given atorvastatin showed few DMSA-USPIO particles and had lower levels of serum indicators. MMP-9 and sCD40L levels in group B were significantly higher than in the other 2 groups (P MRI for clear identification of plaque inflammation and rupture. Rupture plaques were detectable in this way probably due to an activating inflammatory process. Atorvastatin reduced the inflammatory response and stabilizing VP possibly by decreasing MMP-9 and sCD40L levels. PMID:25973795

  14. Gentamicin Sulfate PEG-PLGA/PLGA-H Nanoparticles: Screening Design and Antimicrobial Effect Evaluation toward Clinic Bacterial Isolates

    Science.gov (United States)

    Dorati, Rossella; DeTrizio, Antonella; Spalla, Melissa; Migliavacca, Roberta; Pagani, Laura; Pisani, Silvia; Chiesa, Enrica; Modena, Tiziana; Genta, Ida

    2018-01-01

    Nanotechnology is a promising approach both for restoring or enhancing activity of old and conventional antimicrobial agents and for treating intracellular infections by providing intracellular targeting and sustained release of drug inside infected cells. The present paper introduces a formulation study of gentamicin loaded biodegradable nanoparticles (Nps). Solid-oil-in water technique was studied for gentamicin sulfate nanoencapsulation using uncapped Polylactide-co-glycolide (PLGA-H) and Polylactide-co-glycolide-co-Polyethylenglycol (PLGA-PEG) blends. Screening design was applied to optimize: drug payload, Nps size and size distribution, stability and resuspendability after freeze-drying. PLGA-PEG concentration resulted most significant factor influencing particles size and drug content (DC): 8 w/w% DC and 200 nm Nps were obtained. Stirring rate resulted most influencing factor for size distribution (PDI): 700 rpm permitted to obtain homogeneous Nps dispersion (PDI = 1). Further experimental parameters investigated, by 23 screening design, were: polymer blend composition (PLGA-PEG and PLGA-H), Polyvinylalcohol (PVA) and methanol concentrations into aqueous phase. Drug content was increased to 10.5 w/w%. Nanoparticle lyophilization was studied adding cryoprotectants, polyvinypirrolidone K17 and K32, and sodiumcarboxymetylcellulose. Freeze-drying protocol was optimized by a mixture design. A freeze-dried Nps powder free resuspendable with stable Nps size and payload, was developed. The powder was tested on clinic bacterial isolates demonstrating that after encapsulation, gentamicin sulfate kept its activity. PMID:29329209

  15. Chitosan Microspheres as Radiolabeled Delivery Devices

    International Nuclear Information System (INIS)

    Permtermsin, Chalermsin; Ngamprayad, Tippanan; Phumkhem, Sudkanung; Srinuttrakul, Wannee; Kewsuwan, Prartana

    2007-08-01

    Full text: This study optimized conditions for preparing, characterizing, radiolabeled of chitosan microspheres and the biodistribution of 99mTc-Chitosan microspheres after intravenous administration. Particle size distribution of the microspheres was determined by light scattering. Zeta potential was studied by dynamic light scattering and electrophoresis technique. Biodistribution studies were performed by radiolabeling using 99mTc. The results shown that geometric mean diameter of the microspheres was found to be 77.26?1.96 ?m. Microsphere surface charge of chitosan microspheres was positive charge and zeta potential was 25.80 ? 0.46 mV. The labeling efficiency for this condition was more than 95% and under this condition was stable for at least 6 h. Radioactivity

  16. In vitro Evaluation of Nateglinide-Loaded Microspheres Formulated ...

    African Journals Online (AJOL)

    Keywords: Nateglinide, Microspheres, Micromeritics, Drug release, Ionic ... Oral drug delivery systems (DDS) are commonly divided into immediate release and modified release systems. ..... Albumin Microspheres for Potential Intramuscular.

  17. Interaction of PLGA and trimethyl chitosan modified PLGA nanoparticles with mixed anionic/zwitterionic phospholipid bilayers studied using molecular dynamics simulations

    Science.gov (United States)

    Novak, Brian; Astete, Carlos; Sabliov, Cristina; Moldovan, Dorel

    2012-02-01

    Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable polymer. Nanoparticles of PLGA are commonly used for drug delivery applications. The interaction of the nanoparticles with the cell membrane may influence the rate of their uptake by cells. Both PLGA and cell membranes are negatively charged, so adding positively charged polymers such as trimethyl chitosan (TMC) which adheres to the PLGA particles improves their cellular uptake. The interaction of 3 nm PLGA and TMC-modified-PLGA nanoparticles with lipid bilayers composed of mixtures of phosphatidylcholine and phosphatidylserine lipids was studied using molecular dynamics simulations. The free energy profiles as function of nanoparticles position along the normal direction to the bilayers were calculated, the distribution of phosphatidylserine lipids as a function of distance of the particle from the bilayer was calculated, and the time scale for particle motion in the directions parallel to the bilayer surface was estimated.

  18. Fabrication of Fucoxanthin-Loaded Microsphere(F-LM) By Two Steps Double-Emulsion Solvent Evaporation Method and Characterization of Fucoxanthin before and after Microencapsulation.

    Science.gov (United States)

    Noviendri, Dedi; Jaswir, Irwandi; Taher, Muhammad; Mohamed, Farahidah; Salleh, Hamzah Mohd; Noorbatcha, Ibrahim Ali; Octavianti, Fitri; Lestari, Widya; Hendri, Ridar; Ahmad, Hasna; Miyashita, Kazuo; Abdullah, Alias

    2016-08-01

    Microencapsulation is a promising approach in drug delivery to protect the drug from degradation and allow controlled release of the drug in the body. Fucoxanthin-loaded microsphere (F-LM) was fabricated by two step w/o/w double emulsion solvent evaporation method with poly (L-lactic-coglycolic acid) (PLGA) as carrier. The effect of four types of surfactants (PVA, Tween-20, Span-20 and SDS), homogenization speed, and concentration of PLGA polymer and surfactant (PVA), respectively, on particle size and morphology of F-LM were investigated. Among the surfactants tested, PVA showed the best results with smallest particle size (9.18 µm) and a smooth spherical surface. Increasing the homogenization speed resulted in a smaller mean F-LM particle size [d(0.50)] from 17.12 to 9.18 µm. Best particle size results and good morphology were attained at homogenization speed of 20 500 rpm. Meanwhile, increased PLGA concentration from 1.5 to 11.0 (% w/v) resulted in increased F-LM particle size. The mean particle size [d(0.5)] of F-LM increased from 3.93 to 11.88 µm. At 6.0 (% w/v) PLGA, F-LM showed the best structure and external morphology. Finally, increasing PVA concentration from 0.5 to 3.5 (% w/v) resulted in decreased particle size from 9.18 to 4.86 µm. Fucoxanthin characterization before and after microencapsulation was carried out to assess the success of the microencapsulation procedure. Thermo gravimetry analysis (TGA), glass transition (Tg) temperature of F-LM and fucoxanthin measured using DSC, ATR-FTIR and XRD indicated that fucoxanthin was successfully encapsulated into the PLGA matrix, while maintaining the structural and chemical integrity of fucoxanthin.

  19. Evaluation of radiolabelled microspheres as digesta markers

    International Nuclear Information System (INIS)

    Young, B.A.; Turner, B.V.; Dixon, A.E.; Exley, D.M.; Young, S.B.; Abidin, Z.

    1991-01-01

    The suitability of microspheres as markers for measuring digesta kinetics in sheep was examined. Microspheres offer advantages of uniformity of size and density, and stability during passage through the gastrointestinal tract. They are commercially available labelled with the choice of one of eleven different radionuclides and can be easily measured in digesta and faecal material. Tests comparing several types of digesta markers gave different measures of kinetic parameters when the measurements were made concurrently in the same sheep. However, concurrent measurements derived from use of microspheres were consistent. Microspheres offer a new alternative for digestive studies. (author). 19 refs, 4 tabs

  20. Reversible diminished renal sup(99m)Tc-DMSA uptake during converting-enzyme inhibition in a patient with renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Kremer Hovinga, T K; Beukhof, J R; Donker, A J.M.; Luyk, W H.J. van; Piers, D A

    1984-03-01

    A patient is described who had accelerated hypertension and unilateral renal artery stenosis, and who developed further deterioration in renal function during treatment with captopril, an angiotension-I (AI) converting-enzyme inhibitor. sup(99m)Tc-DMSA uptake was greatly diminished in the stenotic kidney, although renal blood flow and handling of /sup 131/I hippurate was preserved. Uptake of sup(99m)Tc-DMSA in the affected kidney returned after substitution of captopril by the vasodilator minoxidil, while a comparable degree of blood pressure control was maintained. This, caution must be taken when interpreting results of sup(99m)Tc-DMSA scintigraphy in patients with proven or suspected renal artery stenosis treated with an AI converting-enzyme inhibiting drug. Moreover, our finding points to the importance of glomerular filtration in the renal handling of /sup 99/Tc-DMSA.

  1. Reversible diminished renal sup(99m)Tc-DMSA uptake during converting-enzyme inhibition in a patient with renal artery stenosis

    International Nuclear Information System (INIS)

    Kremer Hovinga, T.K.; Beukhof, J.R.; Donker, A.J.M.; Luyk, W.H.J. van; Piers, D.A.

    1984-01-01

    A patient is described who had accelerated hypertension and unilateral renal artery stenosis, and who developed further deterioration in renal function during treatment with captopril, an angiotension-I (AI) converting-enzyme inhibitor. sup(99m)Tc-DMSA uptake was greatly diminished in the stenotic kidney, although renal blood flow and handling of 131 I hippurate was preserved. Uptake of sup(99m)Tc-DMSA in the affected kidney returned after substitution of captopril by the vasodilator minoxidil, while a comparable degree of blood pressure control was maintained. This, caution must be taken when interpreting results of sup(99m)Tc-DMSA scintigraphy in patients with proven or suspected renal artery stenosis treated with an AI converting-enzyme inhibiting drug. Moreover, our finding points to the importance of glomerular filtration in the renal handling of 99 Tc-DMSA. (orig.)

  2. Fabrication of orderly nanostructured PLGA scaffolds using anodic aluminum oxide templates.

    Science.gov (United States)

    Wang, Gou-Jen; Lin, Yan-Cheng; Li, Ching-Wen; Hsueh, Cheng-Chih; Hsu, Shan-Hui; Hung, Huey-Shan

    2009-08-01

    In this research, two simple fabrication methods to fabricate orderly nanostructured PLGA scaffolds using anodic aluminum oxide (AAO) template were conducted. In the vacuum air-extraction approach, the PLGA solution was cast on an AAO template first. The vacuum air-extraction process was then applied to suck the semi-congealed PLGA into the nanopores of the AAO template to form a bamboo sprouts array of PLGA. The surface roughness of the nanostructured scaffolds, ranging from 20 nm to 76 nm, can be controlled by the sucking time of the vacuum air-extraction process. In the replica molding approach, the PLGA solution was cast on the orderly scraggy barrier-layer surface of an AAO membrane to fabricate a PLGA scaffold of concave nanostructure. Cell culture experiments using the bovine endothelial cells (BEC) demonstrated that the nanostructured PLGA membrane can increase the cell growing rate, especially for the bamboo sprouts array scaffolds with smaller surface roughness.

  3. Engineering of lipid-coated PLGA nanoparticles with a tunable payload of diagnostically active nanocrystals for medical imaging.

    Science.gov (United States)

    Mieszawska, Aneta J; Gianella, Anita; Cormode, David P; Zhao, Yiming; Meijerink, Andries; Langer, Robert; Farokhzad, Omid C; Fayad, Zahi A; Mulder, Willem J M

    2012-06-14

    Polylactic-co-glycolic acid (PLGA) based nanoparticles are biocompatible and biodegradable and therefore have been extensively investigated as therapeutic carriers. Here, we engineered diagnostically active PLGA nanoparticles that incorporate high payloads of nanocrystals into their core for tunable bioimaging features. We accomplished this through esterification reactions of PLGA to generate polymers modified with nanocrystals. The PLGA nanoparticles formed from modified PLGA polymers that were functionalized with either gold nanocrystals or quantum dots exhibited favorable features for computed tomography and optical imaging, respectively.

  4. A PLGA-PEG-PLGA Thermosensitive Gel Enabling Sustained Delivery of Ropivacaine Hydrochloride for Postoperative Pain Relief.

    Science.gov (United States)

    Fu, Xudong; Zeng, Huilin; Guo, Jiaping; Liu, Hong; Shi, Zhen; Chen, Huhai; Li, Dezong; Xie, Xiangyang; Kuang, Changchun

    2017-01-01

    Postoperative pain is a complex physiological response to disease and tissue injury. Moderate-to-severe pain typically occurs within 48 h after surgery. Amino amide local anesthetics are widely applied to manage postoperative pain, and they have high efficacy, a low risk for addiction and limited side effects. However, these anesthetics also have short half-lives, often necessitating continuous injection to obtain satisfactory pain relief. In the current work, we used a poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) temperature-sensitive gel to deliver a local anesthetic, ropivacaine hydrochloride (RP), to prolong its analgesic effect. We investigated the influence of polymer and drug concentration on gelation temperature and the in vitro drug release rate from the temperature-sensitive gel. RP-loaded PLGA-PEG-PLGA solution is a liquid at room temperature and forms a gel at temperatures slightly lower than body temperature. With regard to the gel's drug release rate, 37.5, 51.3 and 72.6% of RP was released at 12, 24 and 48 h, respectively. This in vitro drug release profile conformed to the Higuchi equation. To assess pain control efficacy when using the gel, we evaluated the mechanical paw withdrawal reflex threshold, thermal pain threshold and incision cumulative pain scores in a rat incisional model. The results showed that the anti-pain effect of a single injection of RP-loaded gel at the incision site lasted for 48 h, which is significantly longer than the effect produced by injection of RP solution alone. The use of RP-loaded thermosensitive gels could provide a promising method for managing postoperative pain.

  5. Optimization of administered radionuclide activity in renal studies using 99mTc -DMSA in Cuba

    International Nuclear Information System (INIS)

    Diaz Barreto, M.; Perez Diaz, M.; Lopez Bejerano, G. M.; Varela Corona, C.; Paz Viera, J. E.

    2009-01-01

    The present research is focused on the optimization of administered radionuclide activity in renal studies using 9 9mTc-DMSA. The patients sample included 35 subjects, 23 of them were children and the other 12 were adults. Physical and metabolic characteristics of patients, total time of the study as well as radiopharmaceuticals quality and gamma camera performance was considered in the experiments. Image quality of each study was evaluated using subjective criteria from two expert observers, without previous information about administered activity, and objective criteria based on signal/noise ratios and variance of the random noise in the images. They were used to develop clustering and discriminant analysis over the independent variables to detect groups of images with differentiated quality from the physical and mathematical point of view. As a conclusion, we found that it is possible to reduce the given activities in 50%. (Author) 30 refs.

  6. Renal SPECT with 99m Tc-Dmsa. Reorientation and processing

    International Nuclear Information System (INIS)

    Rodriguez, J.L.; Perera, A.; Fraxedas, R.

    1998-01-01

    For the study of different renal affections with repercussion in the parenchyma is widely used the plane gammagraphy wit 99m Tc-Dmsa though not in the same way the SPECT technique. In general, the different inclination and orientation of the longitudinal axes of both kidneys in the patients entail aid to high variability in the detection of the different types of defects which leads to a possible mistaken diagnostic. With a view to this,it was developed in our centre a methodology for the automated reorientation of the different renal volumes obtained by SPECT and its posterior processing, obtaining as result a software with a high grade of independence from the operator. In this way, it is obtained a procedure standardization and so it let us with major rigor to realize evolutive studies of the patients. (Author)

  7. Value of comprehensive renal ultrasound in children with acute urinary tract infection for assessment of renal involvement: comparison with DMSA scintigraphy and final diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Brader, Peter; Riccabona, Michael [Medical University Graz, Division of Pediatric Radiology, Department of Radiology, Graz (Austria); Schwarz, Thomas [Medical University Graz, Division of Nuclear Medicine, Department of Radiology, Graz (Austria); Seebacher, Ursula [Medical University Graz, Department of Pediatric Surgery, Graz (Austria); Ring, Ekkehard [Medical University Graz, Department of Pediatrics, Graz (Austria)

    2008-12-15

    The aim of this study was to evaluate the value of comprehensive renal ultrasound (US), i.e., combining greyscale US and amplitude-coded color Doppler sonography (aCDS), for assessment of urinary tract infection (UTI) in infants and children, compared to (1) {sup 99m}Tc DMSA scintigraphy and (2) final diagnosis. Two hundred eighty-seven children with UTI underwent renal comprehensive US and DMSA scintigraphy. The results were compared with regard to their reliability to diagnose renal involvement, using (1) DMSA scintigraphy and (2) final diagnosis as the gold standard. Sixty-seven children clinically had renal involvement. Sensitivity increased from 84.1% using only aCDS to 92.1% for the combined US approach, using DMSA scintigraphy as the reference standard. When correlated with the final diagnosis, sensitivity for DMSA scintigraphy was 92.5%; sensitivity for comprehensive US was 94.0%. Our data demonstrate an increasing sensitivity using the combination of renal greyscale US supplemented by aCDS for differentiation of upper from lower UTI. Sensitivity for DMSA and comprehensive US was similar for both methods compared to the final diagnosis. Comprehensive US should gain a more important role in the imaging algorithm of children with acute UTI, thereby reducing the radiation burden. (orig.)

  8. Role of Tc99m-dimercaptosuccinic acid (DMSA) in diagnosis of acute urinary tract infection (UTI) in Sudanese children patients

    International Nuclear Information System (INIS)

    Abu baker, S. E. E.

    2003-01-01

    Pediatric nuclear medicine, in order to survive, must be innovative in finding ways of competing with other pediatric imaging studies for better health care. In this study a group of thirty-one patients with urinary tract infection confirmed by clinical investigation, (fever, pain, ....ect), laboratory investigation (RBC and pus cell)and urine culture, were evaluate by nuclear medicine study. The aim of the study was to compare the diagnostic value of cortical scintigraphy using Tc 99m dimercaptosuccinic acid (Tc 99m -DMSA), with two other routine investigations; the intravenous urographic (IVU), and ultrasonography (US), for diagnosis of renal parenchymal abnormality in children. The Tc 99m -DMSA renal scan was utilized as the gold standard test for renal involvement. All patients had Tc 99m -DMSA renal scan, and US, and only 22 patients had contrast IVU. The Tc 99m -DMSA renal scan showed abnormality renal scanning in about 94% of patients, US abnormalities were detected in about 81% of patient, while the IVU detected defects in about 87%. Because the prevalence of upper UTI in children is high, Tc 99m -DMSA renal scan is undoubtedly the available tool for pediatriacicians as a guide in giving appropriate antibiotic therapy and to prevent further renal damage. The study concludes that, the renal cortical scintigraphy with Tc 99m -DMSA has been reported to be a useful children diagnostic study of acute parenchymal renal infections, moreover, is presently the method of choice to detect acute parenchymal infection. (Author)

  9. Comparative study between intravenous urography and renal scintigraphy with DMSA for the diagnosis of renal scars in children with vesicoureteral reflux

    Directory of Open Access Journals (Sweden)

    Clarissa B. Araújo

    2003-12-01

    Full Text Available PURPOSE: To assess the value of intravenous urography (IVU in detecting and grading the renal scar, comparing its results with those of scintigraphy with dimercaptosuccinic acid (DMSA. MATERIALS AND METHODS: The study included 43 children investigated by DMSA and IVU, who had vesicoureteral reflux diagnosed and classified through voiding cystourethrography. RESULTS: Among the kidneys with reflux, there was agreement between the results of DMSA and IVU concerning the presence and the absence of scars in 82.4% of the cases. Based on the results obtained, IVU would have a sensitivity of 66.6%, specificity of 94.4%; accuracy of 82.5%; positive predictive value (PPV of 90% and negative predictive value (NPV of 79%, when compared with DMSA results. Our data also confirm the close relation between the reflux grade and the presence of renal scar, since 75% of the kidneys with grade IV and V reflux presented scars. In relation to the grading of nephropathy, in 78% of patients the classification of the scar by both methods was identical. The highest disagreement was verified in the group with segmental scar on DMSA, where 41.6% of the kidneys were classified as normal on IVU. CONCLUSION: The data obtained confirm that the scintigraphy with DMSA is essential in the investigation of patients with renal scar, and cannot be replaced by IVU, due to its low sensitivity and lower ability of satisfactory grading.

  10. Value of comprehensive renal ultrasound in children with acute urinary tract infection for assessment of renal involvement: comparison with DMSA scintigraphy and final diagnosis

    International Nuclear Information System (INIS)

    Brader, Peter; Riccabona, Michael; Schwarz, Thomas; Seebacher, Ursula; Ring, Ekkehard

    2008-01-01

    The aim of this study was to evaluate the value of comprehensive renal ultrasound (US), i.e., combining greyscale US and amplitude-coded color Doppler sonography (aCDS), for assessment of urinary tract infection (UTI) in infants and children, compared to (1) 99m Tc DMSA scintigraphy and (2) final diagnosis. Two hundred eighty-seven children with UTI underwent renal comprehensive US and DMSA scintigraphy. The results were compared with regard to their reliability to diagnose renal involvement, using (1) DMSA scintigraphy and (2) final diagnosis as the gold standard. Sixty-seven children clinically had renal involvement. Sensitivity increased from 84.1% using only aCDS to 92.1% for the combined US approach, using DMSA scintigraphy as the reference standard. When correlated with the final diagnosis, sensitivity for DMSA scintigraphy was 92.5%; sensitivity for comprehensive US was 94.0%. Our data demonstrate an increasing sensitivity using the combination of renal greyscale US supplemented by aCDS for differentiation of upper from lower UTI. Sensitivity for DMSA and comprehensive US was similar for both methods compared to the final diagnosis. Comprehensive US should gain a more important role in the imaging algorithm of children with acute UTI, thereby reducing the radiation burden. (orig.)

  11. Tc-99m-DMSA renal uptake rate and renal volume of elderly persons

    International Nuclear Information System (INIS)

    Ohishi, Yukihiko; Machida, Toyohei; Kido, Akira

    1987-01-01

    Renal function of erderly persons was evaluated by the radionuclide renal function test based on the renal uptake rate and the renal volume determined by Tc-99m-DMSA transectional tomographic images using single photon emission computed tomography (SPECT). Forty-three erderly cases (13 healthy persons and 30 patients with various types of renal disorders) aged between 60 and 87 on an average of 70 were studied and compared with results obtained from 20 healthy adults (18 - 45 years old). Renal volume was calculated from the summation of voxels in the region districted by equi-count threshold level (percentage to maximum count) on each section of the SPECT image. Attenuation correction was made by GE-STAR protocol utilizing Sorrenson's precorrection method. The renal uptake rate was expressed as a percentage of the total radioactivity detected within the renal volume, against an amount of dose injected. In the 26 kidneys of 13 healthy elderly persons, Tc-99m-DMSA renal uptake was 23 ± 5 %, which was significantly lower (p < 0.01) than that of healthy adults being 27 ± 2 %. A correlation coefficient between renal volume and uptake of 79 kidneys of 43 elderly persons was 0.5081 (p < 0.01). Creatinine clearance (Ccr) was better correlated with the total renal uptake (r = 0.6471, p < 0.01) than with the total renal volume (r = 0.3592, p < 0.01). This method is considered to be useful for clinical purpose as a test of renal function for elderly persons since it requires neither blood nor urine samples. (author)

  12. Glass microspheres for medical applications

    Science.gov (United States)

    Conzone, Samuel David

    Radioactive dysprosium lithium borate glass microspheres have been developed as biodegradable radiation delivery vehicles for the radiation synovectomy treatment of rheumatoid arthritis. Once injected into a diseased joint, the microspheres deliver a potent dose of radiation to the diseased tissue, while a non-uniform chemical reaction converts the glass into an amorphous, porous, hydrated dysprosium phosphate reaction product. The non-radioactive, lithium-borate component is dissolved from the glass (up to 94% weight loss), while the radioactive 165Dy reacts with phosphate anions in the body fluids, and becomes "chemically" trapped in a solid, dysprosium phosphate reaction product that has the same size as the un-reacted glass microsphere. Ethylene diamine tetraacetate (EDTA) chelation therapy can be used to dissolve the dysprosium phosphate reaction product after the radiation delivery has subsided. The dysprosium phosphate reaction product, which formed in vivo in the joint of a Sprague-Dawley rat, was dissolved by EDTA chelation therapy in 100 Gy) of localized beta radiation to a treatment site within the body, followed by complete biodegradability. The non-uniform reaction process is a desirable characteristic for a biodegradable radiation delivery vehicle, but it is also a novel material synthesis technique that can convert a glass to a highly porous materials with widely varying chemical composition by simple, low-temperature, glass/solution reaction. The reaction product formed by nonuniform reaction occupies the same volume as the un-reacted glass, and after drying for 1 h at 300°C, has a specific surface area of ≈200 m2/g, a pore size of ≈30 nm, and a nominal crushing strength of ≈10 MPa. Finally, rhenium glass microspheres, composed of micron-sized, metallic rhenium particles dispersed within a magnesium alumino borate glass matrix were produced by sintering ReO2 powder and glass frit at 1050°C. A 50 mg injection of radioactive rhenium glass

  13. Evaluation of kidney repair capacity using 99mTc-DMSA in ischemia/reperfusion injury models.

    Science.gov (United States)

    Kwak, Wonjung; Jang, Hee-Seong; Belay, Takele; Kim, Jinu; Ha, Yeong Su; Lee, Sang Woo; Ahn, Byeong-Cheol; Lee, Jaetae; Park, Kwon Moo; Yoo, Jeongsoo

    2011-03-04

    Quantitative (99m)Tc-DMSA renal uptake was studied in different renal ischemia/reperfusion (I/R) mice models for the assessment of renal repair capacity. Mice models of nephrectomy, uni- and bi-lateral I/R together with sham-operated mice were established. At 1h, 1d, 4d, 1, 2 and 3 wk after I/R, (99m)Tc-DMSA (27.7 ± 1.3 MBq) was injected via tail vein and after 3h post-injection, the mice were scanned for 30 min with pinhole equipped gamma camera. Higher uptake of (99m)Tc-DMSA was measured in normal kidneys of uni-lateral I/R model and nephrectomized kidney I/R model at 3 wk post-surgery. Comparing the restoration capacities of the affected kidneys of nephrectomy, uni- and bi-lateral I/R models, higher repair capacity was observed in the nephrectomized model followed by bi-lateral then uni-lateral models. The normal kidney may retard the restoration of damaged kidney in uni-lateral I/R model. Moreover, 3 wk after Uni-I/R, the size of injured kidney was significantly smaller than non-ischemic contralateral and sham operated kidneys, while nephrectomy I/R kidneys were significantly enlarged compared to all others at 3 wk post-surgery. Very strong correlation between (99m)Tc-DMSA uptake and weight of dissected kidneys in I/R models was observed. Consistent with (99m)Tc-DMSA uptake results, all histological results indicate that kidney recovery after injury is correlated with the amount of intact tubules and kidney sizes. In summary, our study showed good potentials of (99m)Tc-DMSA scan as a promising non-invasive method for evaluation of kidney restoration after I/R injuries. Interestingly, mice with Bi-I/R injury showed faster repair capacity than those with uni-I/R. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Surface functionalisation of PLGA nanoparticles for gene silencing

    DEFF Research Database (Denmark)

    Andersen, Morten Østergaard; Lichawska, Agata; Arpanaei, Ayyoob

    2010-01-01

    . In addition, particles containing cetylated-PEI achieved 64% silencing of TNFα in J774.1 cells. This rapid method for surface modification of PLGA nanoparticles promotes its application for alternative cetylated functional derivatives as a strategy to control specific biological properties of nanoparticles....

  15. Nanoporous Calcium Silicate and PLGA Bio composite for Bone Repair

    International Nuclear Information System (INIS)

    Su, J.; Wang, Z.; Wu, Y.; Cao, L.; Ma, Y.; Yu, B.; Li, M.; Yan, Y.

    2010-01-01

    Nanoporous calcium silicate (n-CS) with high surface area was synthesized using the mixed surfactants of EO20PO70EO20 (polyethylene oxide)20(polypropylene oxide)70(polyethylene oxide)20, P123) and hexadecyltrimethyl ammonium bromide (CTAB) as templates, and its composite with poly(lactic acid-co-glycolic acid) (PLGA) were fabricated. The results showed that the n-CS/PLGA composite (n-CPC) with 20 wt% n-CS could induce a dense and continuous layer of apatite on its surface after soaking in simulated body fluid (SBF) for 1 week, suggesting the excellent in vitro bioactivity. The n-CPC could promote cell attachment on its surfaces. In addition, the proliferation ratio of MG63 cells on n-CPC was significantly higher than PLGA; the results demonstrated that n-CPC had excellent cytocompatibility. We prepared n-CPC scaffolds that contained open and interconnected macroporous ranging in size from 200 to 500 μ m. The n-CPC scaffolds were implanted in femur bone defect of rabbits, and the in vivo biocompatibility and osteogenicity of the scaffolds were investigated. The results indicated that n-CPC scaffolds exhibited good biocompatibility, degradability, and osteogenesis in vivo. Collectively, these results suggested that the incorporation of n-CS in PLGA produced biocomposites with improved bioactivity and biocompatibility.

  16. Investigation in uro-nephrology (2): renal cortical scintigraphy using {sup 99m}Tc-Dmsa in children; Enquete en uro-nephrologie (2): la scintigraphie renale au 99mTc-DMSA chez l'enfant

    Energy Technology Data Exchange (ETDEWEB)

    Archambaud, F. [Centre Hospitalier Universitaire de Bicetre, 94 - Le Kremlin-Bicetre (France); Olivier, P. [Centre Hospitalier Universitaire Nancy-Brabois, 54 - Vandoeuvre-les-Nancy (France); Guillet, J. [Centre Hospitalier Universitaire, 47 - Agen (France); Wioland, M. [Centre Hospitalier Universitaire Armand Trousseau, 75 - Paris (France); Bonnin, F. [Centre Hospitalier Universitaire Beaujon, 92 - Clichy (France)

    2002-08-01

    We present the results of a national investigation about the daily practice of renal cortical scintigraphy using {sup 99m}Tc-DMSA in children by comparison with the recommendations of the international consensus from the experts designated by the Scientific Committee of 'Radionuclides in Nephrology'. Questions were related to radiopharmaceutical image acquisition, processing and visualisation, relative renal function determination and indications of renal scan in urinary tract infection. National daily practice are similar to the one suggested by the international consensus about many aspects. However, a controversy exists between the experts in acquiring pinhole or tomographic images. Similarly to the international consensus, {sup 99m}Tc-DMSA renal scan is widely performed for detection of renal sequelae, while its indication in acute pyelonephritis remains to define. (authors)

  17. Microsphere estimates of blood flow: Methodological considerations

    International Nuclear Information System (INIS)

    von Ritter, C.; Hinder, R.A.; Womack, W.; Bauerfeind, P.; Fimmel, C.J.; Kvietys, P.R.; Granger, D.N.; Blum, A.L.

    1988-01-01

    The microsphere technique is a standard method for measuring blood flow in experimental animals. Sporadic reports have appeared outlining the limitations of this method. In this study the authors have systematically assessed the effect of blood withdrawals for reference sampling, microsphere numbers, and anesthesia on blood flow estimates using radioactive microspheres in dogs. Experiments were performed on 18 conscious and 12 anesthetized dogs. Four blood flow estimates were performed over 120 min using 1 x 10 6 microspheres each time. The effects of excessive numbers of microspheres pentobarbital sodium anesthesia, and replacement of volume loss for reference samples with dextran 70 were assessed. In both conscious and anesthetized dogs a progressive decrease in gastric mucosal blood flow and cardiac output was observed over 120 min. This was also observed in the pancreas in conscious dogs. The major factor responsible for these changes was the volume loss due to the reference sample withdrawals. Replacement of the withdrawn blood with dextran 70 led to stable blood flows to all organs. The injection of excessive numbers of microspheres did not modify hemodynamics to a greater extent than did the injection of 4 million microspheres. Anesthesia exerted no influence on blood flow other than raising coronary flow. The authors conclude that although blood flow to the gastric mucosa and the pancreas is sensitive to the minor hemodynamic changes associated with the microsphere technique, replacement of volume loss for reference samples ensures stable blood flow to all organs over a 120-min period

  18. Thermal analysis of iron hydroxide microspheres

    International Nuclear Information System (INIS)

    Turcanu, C.N.; Cornescu, M.

    1979-03-01

    The thermal treatment is an important step in the preparative technology of the iron oxids microspheres with well established mechanical, physical and chemical characteristics. The first indications on the heating procedure have been obtained from the thermal analysis on iron hydroxide microspheres prepared by the support precipitation and internal gelification methods. (author)

  19. Encapsulated PDMS microspheres with reactive handles

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Ma, Baoguang; Li, Li

    2014-01-01

    , cured PDMS microspheres are coated with poly(methyl methacrylate) using a chemical process (solvent evaporation technique). Three solvents are used in three different experiments: dichloromethane, tetrahydrofuran, and acetone. The composition and morphology of the cured PDMS microspheres and PMMA coated...

  20. Microencapsulation and microspheres for food applications

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2015-01-01

    This book provides an update on the latest developments, challenges, and opportunities in the highly expanding field of microencapsulation and microspheres for food applications, examining the various types of microspheres and microcapsules essential to those who need to develop stable and

  1. TIPS to manipulate myogenesis: retention of myoblast differentiation capacity using microsphere culture

    Directory of Open Access Journals (Sweden)

    N Parmar

    2015-07-01

    Full Text Available Cell therapy is an emerging option for regenerating skeletal muscle. Improved delivery methods for anchorage-dependent myoblasts are likely to improve integration and function of transplanted muscle cells. Highly porous microspheres, produced using thermally induced phase separation (TIPS, have features ideally suited for minimally invasive cell delivery. The purpose of this study was to investigate, for the first time, the use of TIPS microspheres as highly porous microcarriers for manipulation of human skeletal muscle myoblasts (HSMM under defined culture conditions. HSMM cells readily attached to the surface of poly (DL-lactide-co-glycolide (PLGA TIPS microcarriers, where they were induced to continue proliferating or to be driven towards differentiation whilst under static-dynamic culture conditions for 7 days. Switching from proliferation medium to differentiation medium for 7 days, resulted in increased protein expression of skeletal muscle cell contractile apparatus components, MyoD and skeletal muscle myosin heavy chain, compared with cells cultured on conventional culture plasticware for the same duration (p < 0.001. Growth of myoblasts on the surface of the microcarriers and their migration following simulated delivery, caused no change to the proliferative capacity of cells over 7 days. Results from this study demonstrate that TIPS microspheres provide an ideal vehicle for the expansion and delivery of myoblasts for therapeutic applications. Transplantation of myoblasts anchored to a substrate, rather than in suspension, will reduce the amount of ex vivo manipulation required during preparation of the product and allows cells to be delivered in a more natural state. This will improve the ability to control cell dosage and increase the likelihood of efficacy.

  2. U3O8 microspheres sintering kinetics

    International Nuclear Information System (INIS)

    Godoy, A.L.E.

    1986-01-01

    U 3 O 8 microspheres sintering kinetics was determined using a hot-stage optical microscopy apparatus, able to reach temperature up to 1350 0 C in controlled atmospheres. The sintered material had its microstructure analysed by optical and electron microscopy. The microspheres were characterized initialy utilizing X-ray diffractometry and thermogravimetry. The equation which describes the microspheres shrinkage in function of the time was obtained using finite difference analysis X-ray diffractometry indicated hexagonal structure for the microspheres main starting material, ammonium diuranate thermogravimetric analysis showed reduction of this material to U 3 O 8 at 600 0 C. Ceramography results showed 5 hours sintered microspheres grain sizes G vary with the temperature. Sintered U 3 O 8 micrographs compared with published results for UO 2 , indicate similar homogeneity microstructural characteristics and suggest the processed micorspheres to be potentially useful as nuclear fuels. (Author) [pt

  3. Magnetic susceptibility characterisation of superparamagnetic microspheres

    Science.gov (United States)

    Grob, David Tim; Wise, Naomi; Oduwole, Olayinka; Sheard, Steve

    2018-04-01

    The separation of magnetic materials in microsystems using magnetophoresis has increased in popularity. The wide variety and availability of magnetic beads has fuelled this drive. It is important to know the magnetic characteristics of the microspheres in order to accurately use them in separation processes integrated on a lab-on-a-chip device. To investigate the magnetic susceptibility of magnetic microspheres, the magnetic responsiveness of three types of Dynabeads microspheres were tested using two different approaches. The magnetophoretic mobility of individual microspheres is studied using a particle tracking system and the magnetization of each type of Dynabeads microsphere is measured using SQUID relaxometry. The magnetic beads' susceptibility is obtained at four different applied magnetic fields in the range of 38-70 mT for both the mobility and SQUID measurements. The susceptibility values in both approaches show a consistent magnetic field dependence.

  4. Preparation and characterization of bee venom-loaded PLGA particles for sustained release.

    Science.gov (United States)

    Park, Min-Ho; Jun, Hye-Suk; Jeon, Jong-Woon; Park, Jin-Kyu; Lee, Bong-Joo; Suh, Guk-Hyun; Park, Jeong-Sook; Cho, Cheong-Weon

    2016-12-14

    Bee venom-loaded poly(lactic-co-glycolic acid) (PLGA) particles were prepared by double emulsion-solvent evaporation, and characterized for a sustained-release system. Factors such as the type of organic solvent, the amount of bee venom and PLGA, the type of PLGA, the type of polyvinyl alcohol, and the emulsification method were considered. Physicochemical properties, including the encapsulation efficiency, drug loading, particle size, zeta-potential and surface morphology were examined by Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The size of the bee venom-loaded PLGA particles was 500 nm (measured using sonication). Zeta-potentials of the bee venom-loaded PLGA particles were negative owing to the PLGA. FT-IR results demonstrated that the bee venom was completely encapsulated in the PLGA particles, indicated by the disappearance of the amine and amide peaks. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated that the bee venom in the bee venom-loaded PLGA particles was intact. In vitro release of the bee venom from the bee venom-loaded PLGA particles showed a sustained-release profile over 1 month. Bee venom-loaded PLGA particles can help improve patients' quality of life by reducing the number of injections required.

  5. Fabrication of mineralized electrospun PLGA and PLGA/gelatin nanofibers and their potential in bone tissue engineering.

    Science.gov (United States)

    Meng, Z X; Li, H F; Sun, Z Z; Zheng, W; Zheng, Y F

    2013-03-01

    Surface mineralization is an effective method to produce calcium phosphate apatite coating on the surface of bone tissue scaffold which could create an osteophilic environment similar to the natural extracellular matrix for bone cells. In this study, we prepared mineralized poly(D,L-lactide-co-glycolide) (PLGA) and PLGA/gelatin electrospun nanofibers via depositing calcium phosphate apatite coating on the surface of these nanofibers to fabricate bone tissue engineering scaffolds by concentrated simulated body fluid method, supersaturated calcification solution method and alternate soaking method. The apatite products were characterized by the scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD) methods. A large amount of calcium phosphate apatite composed of dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HA) and octacalcium phosphate (OCP) was deposited on the surface of resulting nanofibers in short times via three mineralizing methods. A larger amount of calcium phosphate was deposited on the surface of PLGA/gelatin nanofibers rather than PLGA nanofibers because gelatin acted as nucleation center for the formation of calcium phosphate. The cell culture experiments revealed that the difference of morphology and components of calcium phosphate apatite did not show much influence on the cell adhesion, proliferation and activity. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Accumulation of Tc99m-DMSA-3 in the spleen in a case of multiple myeloma with associated amyloidosis

    Directory of Open Access Journals (Sweden)

    Barai Sukanta

    2005-01-01

    Full Text Available We describe a case of a 58-year-old male with longstanding hypertension and Type 2 diabetes mellitus who developed sudden onset renal impairment. The first clue to the possible presence of amyloidosis in this case was provided by the radionuclide renal cortical scan performed with trivalent dimercapto succinic acid (Tc99m-DMSA-3, which revealed intense tracer uptake in the spleen suggesting amyloid deposit. Further workup to ascertain the cause of amyloidosis led to the diagnosis of multiple myeloma. We conclude that in cases of extra-renal or splenic accumulation of Tc99m-DMSA-3, a diagnosis of amyloidosis should be considered, in an appropriate clinical setting.

  7. Comparative assessment of renal Tc-99m DMSA scan and renal sonography findings in complication of urinary tract infections

    International Nuclear Information System (INIS)

    Alavi, M.; Rasekhi, A.

    2002-01-01

    Urinary tract infection is a common disease in childhood specially in female. In this study 50 patients with established diagnosis of urinary tract infection were evaluated by both renal scan with Tc-99m DMSA and renal sonography. The study revealed that most urinary tract infections are in children, female sex between 5-9 years of age. Therefore the most important complications (renal scarring) are also common in this age-sex distribution. Occurrence of renal scars increase with increasing the number of recurrent infections. Vesicoureteral reflux is one of the most important, common risk factors for renal scarring. Renal Tc-99m Dmsa scan is more sensitive than renal sonography in detecting the renal scars

  8. Results of a five-year study of 99mTc DMSA renal scintigraphy in children and adolescents following acute pyelonephritis

    International Nuclear Information System (INIS)

    Chroustova, D.; Palyzova, D.; Kolska, M.; Urbanova, I.

    2006-01-01

    Renal scintigraphy, generally using 99' mTc-DMSA, is the accepted reference standard for detection of renal cortical changes. The timing of the test, i.e., whether an acute 99m Tc-DMSA scan, a follow-up only or both scans should be performed, however, remains open to discussion. In our study, a six-month follow- up DMSA scan was performed in all the children diagnosed with a first attack of acute pyelonephritis (APN) in two large paediatric clinics of Charles University's 3 rd School of Medicine in Prague during a five-year period. All diagnoses were confirmed by a paediatric nephrologist. 382 children (267 girls, 115 boys) aged between 7 months and 19 years were included in the study. For analytical purposes, the patients were divided into 4 age groups: I - less than 1 year of age, II - 1-5 years, III - 5-10 years, and IV - 10-19 years. In all children younger than five years, a micturition cystourethrogram (MCUG) for detection of vesicoureteric reflux (VUR) was performed between one and three months after the APN episode. Static renal scintigraphy, using an HR collimator with parallel holes was performed using a planar Gamma camera MB 9200 (Gamma Budapest) in all children six months after APN, with a complement of pinhole images, SPECT or PSPECT of the kidneys. 1. In group I, all four children with positive VUR on MCUG had a pathological DMSA scan, while only two of the 32 patients with negative VUR had a pathological DMSA. 2. In group II, 17 children had VUR on MCUG, six of them with a pathological and 11 with a normal DMSA scan. Most of the 221 children without VUR had a normal DMSA scintigraphy; pathological findings were present in 17 children only. 3. In group III, all children with VUR, but only 5 out of 53 without VUR, had a pathological DMSA scan. 4. Five out of 50 children in group IV had a pathological DMSA. APN occurred most frequently in group II (62.3%, or 238 children) and ranged between 10-15% in the remaining groups. APN was found very frequently

  9. Contribution of the renal scintiscanning with the DMSA in the diagnosis of Pyelonephritides, acute and chronic, of the child

    International Nuclear Information System (INIS)

    Sellem, Ali

    2008-01-01

    In the case of urinary infection of children, a complete clinical and biological picture can be enough to retain the diagnosis of a high attack. However, this possibility is rare. In the contrary cases, a renal scintiscanning with the DMSA must be carried out with the acute phase, to confirm the diagnosis. For the children carrying acute pyelonephritis, a scintigraphic control is necessary to detect the cortical scars.

  10. The clinical application of 99Tcm-DMSA renal cortical scintigraphy in children with urinary tract infection

    International Nuclear Information System (INIS)

    Zhao Ruifang; Zeng Jihua; Xu Hong; Ji Zhiying; Yuan Hong

    2002-01-01

    Objective: To study the value of 99 Tc m -dimercaptosuccinic acid (DMSA) renal cortical scintigraphy in distinguishing between upper urinary tract infection (UUTI) and lower UTI (LUTI), determining renal scarring, and following-up curative effect for UTI in children. Methods: The authors reviewed 252 results of 99 Tc m -DMSA renal cortical scintigraphy in children with UTIs during a period of the past five years. The age of the patients was from 1 month to 14 years. The ratio of males: females was 94:158. A standard 99 Tc m -DMSA renal cortical scintigraphic protocol was used. The studies were scored as normal (indicating LUTI) and abnormal (indicating acute pyelonephritis or renal scarring). And differential function of renal was calculated. Results: Of 252 children with UTI, 110 cases had normal images diagnosed as with LUTI. 142 cases had abnormal images, 116 cases were diagnosed as with acute pyelonephritis, 26 cases were diagnosed as with renal cortical scars. The differential function range of LUTI was 46%-54%. Of UUTIs, the differential function of single renal involved was less than 45%. Of 142 UUTIs, 17 cases repeatedly underwent renal cortical scan after therapy. 12 of 13 cases with acute pyelonephritis completely recovered normal or obviously ameliorated after 6 months, 1 cases did not show any change after 4 months. Four cases were found with renal scarring, and showed little change on repeated images for the following 6 months. conclusions: 99 Tc m -DMSA renal cortical scintigraphy is of valuable significance in distinguishing between upper and lower UTI, and in estimating renal scarring. The sequelae of renal infection can be monitored by renal cortical scan. A follow-up of 6 months may be recommended after therapy

  11. THE IMPORTANCE OF 99m-Tc DMSA RENAL SCINTIGRAPHY IN EVALUATION OF RENAL LESIONS IN CHILDREN WITH ACUTE PYELONEPHRITIS

    Directory of Open Access Journals (Sweden)

    N Ataei

    2008-11-01

    Full Text Available "nUrinary tract infection (UTI may lead to irreversible changes in renal parenchyma. Early diagnosis using scintigraphy with technetium-99m-labeled dimercaptosuccinic acid (DMSA scan and early treatment may decrease or prevent development of renal parenchymal lesions. The aim of this study was to assess the occurrence of renal parenchymal lesion in children admitted with a first-time symptomatic UTI and to evaluate the relation between renal parenchymal damage and severity of vesicoureteral reflux (VUR. A total of 102 children with first time acute pyelonephritis (APN were enrolled in the study. All children studied with DMSA scan and ultrasonography (US. Voiding cystourethrography (VCUG was performed in 98 children when urine culture became negative. Changes on the DMSA scan and US were found in 178 (88% and 5 (2.4% out of 203 renal units during the acute phase, respectively. All abnormal renal units on US showed severe parenchymal involvement on DMSA. We also found significant correlation between severity of VUR and abnormal US results on kidneys. Of 40 kidneys with reflux, 38 (95% were found to have abnormal renal scan. Among 155 kidneys with non-refluxing ureters 132 (85.2% revealed parenchymal changes on renal cortical scintigraphy. Kidneys with moderate to severe reflux were more likely to have severe renal involvement. We found a high incidence of renal parenchymal changes in children with APN. Additionally, renal involvement was significantly higher in children with moderate to severe reflux. When there are high-grade VUR and female gender, the risk of renal parenchymal involvement is higher.

  12. Fabrication of mineralized electrospun PLGA and PLGA/gelatin nanofibers and their potential in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z.X. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Li, H.F. [Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China); Sun, Z.Z. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, W., E-mail: zhengwei@hrbeu.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2013-03-01

    Surface mineralization is an effective method to produce calcium phosphate apatite coating on the surface of bone tissue scaffold which could create an osteophilic environment similar to the natural extracellular matrix for bone cells. In this study, we prepared mineralized poly(D,L-lactide-co-glycolide) (PLGA) and PLGA/gelatin electrospun nanofibers via depositing calcium phosphate apatite coating on the surface of these nanofibers to fabricate bone tissue engineering scaffolds by concentrated simulated body fluid method, supersaturated calcification solution method and alternate soaking method. The apatite products were characterized by the scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD) methods. A large amount of calcium phosphate apatite composed of dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HA) and octacalcium phosphate (OCP) was deposited on the surface of resulting nanofibers in short times via three mineralizing methods. A larger amount of calcium phosphate was deposited on the surface of PLGA/gelatin nanofibers rather than PLGA nanofibers because gelatin acted as nucleation center for the formation of calcium phosphate. The cell culture experiments revealed that the difference of morphology and components of calcium phosphate apatite did not show much influence on the cell adhesion, proliferation and activity. - Highlights: Black-Right-Pointing-Pointer Ca-P phases were coated on PLGA/gelatin electrospun nanofiber membranes within 3 h. Black-Right-Pointing-Pointer Ca-P coatings prepared by 3 methods exhibited different structures and components. Black-Right-Pointing-Pointer The Ca-P coating weight increase depends on the apatite nucleation velocity. Black-Right-Pointing-Pointer Surface hydrophilicity enhanced the velocity and quantity of apatite nucleation. Black-Right-Pointing-Pointer The resulting Ca-P apatite coatings exhibit good biocompatibility to MG63 cells.

  13. Fabrication of mineralized electrospun PLGA and PLGA/gelatin nanofibers and their potential in bone tissue engineering

    International Nuclear Information System (INIS)

    Meng, Z.X.; Li, H.F.; Sun, Z.Z.; Zheng, W.; Zheng, Y.F.

    2013-01-01

    Surface mineralization is an effective method to produce calcium phosphate apatite coating on the surface of bone tissue scaffold which could create an osteophilic environment similar to the natural extracellular matrix for bone cells. In this study, we prepared mineralized poly(D,L-lactide-co-glycolide) (PLGA) and PLGA/gelatin electrospun nanofibers via depositing calcium phosphate apatite coating on the surface of these nanofibers to fabricate bone tissue engineering scaffolds by concentrated simulated body fluid method, supersaturated calcification solution method and alternate soaking method. The apatite products were characterized by the scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffractometry (XRD) methods. A large amount of calcium phosphate apatite composed of dicalcium phosphate dihydrate (DCPD), hydroxyapatite (HA) and octacalcium phosphate (OCP) was deposited on the surface of resulting nanofibers in short times via three mineralizing methods. A larger amount of calcium phosphate was deposited on the surface of PLGA/gelatin nanofibers rather than PLGA nanofibers because gelatin acted as nucleation center for the formation of calcium phosphate. The cell culture experiments revealed that the difference of morphology and components of calcium phosphate apatite did not show much influence on the cell adhesion, proliferation and activity. - Highlights: ► Ca–P phases were coated on PLGA/gelatin electrospun nanofiber membranes within 3 h. ► Ca–P coatings prepared by 3 methods exhibited different structures and components. ► The Ca–P coating weight increase depends on the apatite nucleation velocity. ► Surface hydrophilicity enhanced the velocity and quantity of apatite nucleation. ► The resulting Ca–P apatite coatings exhibit good biocompatibility to MG63 cells.

  14. A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA)

    Science.gov (United States)

    Forman, J; Moline, J; Cernichiari, E; Sayegh, S; Torres, J C; Landrigan, M M; Hudson, J; Adel, H N; Landrigan, P J

    2000-06-01

    Nine children and their mother were exposed to vapors of metallic mercury. The source of the exposure appears to have been a 6-oz vial of mercury taken from a neighbor's home. The neighbor reportedly operated a business preparing mercury-filled amulets for practitioners of the Afro-Caribbean religion Santeria. At diagnosis, urinary mercury levels in the children ranged from 61 to 1,213 microg/g creatinine, with a geometric mean of 214.3 microg/m creatinine. All of the children were asymptomatic. To prevent development of neurotoxicity, we treated the children with oral meso-2,3-dimercaptosuccinic acid (DMSA). During chelation, the geometric mean urine level rose initially by 268% to 573.2 microg mercury/g creatinine (p<0.0005). At the 6-week follow-up examination after treatment, the geometric mean urine mercury level had fallen to 102.1 microg/g creatinine, which was 17.8% of the geometric mean level observed during treatment (p<0.0005) and 47.6% of the original baseline level (p<0.001). Thus, oral chelation with DMSA produced a significant mercury diuresis in these children. We observed no adverse side effects of treatment. DMSA appears to be an effective and safe chelating agent for treatment of pediatric overexposure to metallic mercury.

  15. Paediatric 99mTc-DMSA imaging: reducing distress and rate of sedation using a psychological approach

    International Nuclear Information System (INIS)

    Train, H.; Colville, G.; Allan, R.; Thurlbeck, S.

    2006-01-01

    Aim: To evaluate the effect of a psychological approach on distress and sedation rates in children undergoing dimer captosuccinic acid-labelled with technetium-99 (99mTc) DMSA imaging. Materials and methods: Baseline data, on a retrospective consecutive sample of children examined using DMSA over a 6-month period (n = 81), were collected via medical note search and postal questionnaire. A further consecutive sample of 40 children was recruited prospectively to the intervention, which consisted of distraction during medical procedures and environmental manipulation. In addition half of the intervention group were provided with a photo-booklet depicting a coping child model, together with a letter offering advice to parents on how to prepare their child for the procedure. Results: Sedation rates were lower (p = 0.003) and service satisfaction ratings higher (p = 0.002) in the Intervention group as compared with the Baseline group. Within the intervention condition, children who received the photo-booklet displayed less distress before the procedure (p = 0.01) than those who did not. Also families who received the photo-booklet were more likely to attend the appointment (p = 0.024). Conclusion: In this study, the use of a psychological approach was associated with lower rates of distress and sedation in children undergoing 99mTc-DMSA imaging, without compromising image quality

  16. Influence of splenectomy on the biodistribution of technetium-99m dimercaptosuccinic acid (99mTc-DMSA) in rats

    International Nuclear Information System (INIS)

    Acucena, Maria Kadja Meneses Torres; Pereira, Kercia Regina Santos Gomes; Villarim Neto, Arthur; Rego, Amalia Cinthia Meneses; Bernardo-Filho, Mario; Azevedo, Italo Medeiros; Araujo Filho, Irami; Medeiros, Aldo Cunha

    2008-01-01

    This study aimed to evaluate if the splenectomy alters the biodistribution of 99mTc-DMSA and renal function in Wistar rats. The animals were separated in the groups: splenectomy (n = 6) and control (n = 6). After splenectomy (15 days), the administration of 0.1 ml of 99mTc-DMSA IV (0.48 MBq) was carried out. Thirty minutes later, kidney, heart, lung, thyroid, stomach, bladder and femur and samples of blood were isolated. The organs were weighed, counted and the percentage of radioactivity /g (%ATI/g) determined. Serum urea and creatinine, hematocrit, leukocytes and platelets were measured. Statistics by t test (p<0.05) was done. There was a significant reduction in %ATI/g in kidney and blood (p<0.05) of splenectomized animals, a significant increase (p<0.05) of urea (88.8 ± 18.6 mg/dL) and creatinine (0.56 ± 0.08 mg/dL), compared to the controls (51.5±1.6, 0.37±0.02 mg/dL, respectively), as well as increase in platelets and leucocytes, and hematocrit reduction. The analysis of the results indicates that in rats, splenectomy seems to alter the renal function and the uptake of 99mTc-DMSA. (author)

  17. Influence of splenectomy on the biodistribution of technetium-99m dimercaptosuccinic acid (99mTc-DMSA) in rats

    Energy Technology Data Exchange (ETDEWEB)

    Acucena, Maria Kadja Meneses Torres; Pereira, Kercia Regina Santos Gomes; Villarim Neto, Arthur; Rego, Amalia Cinthia Meneses [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias da Saude; Bernardo-Filho, Mario [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Dept. de Biofisica e Biometria; Azevedo, Italo Medeiros; Araujo Filho, Irami; Medeiros, Aldo Cunha [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Cirurgia]. E-mail: aldo@ufrnet.br

    2008-12-15

    This study aimed to evaluate if the splenectomy alters the biodistribution of 99mTc-DMSA and renal function in Wistar rats. The animals were separated in the groups: splenectomy (n = 6) and control (n = 6). After splenectomy (15 days), the administration of 0.1 ml of 99mTc-DMSA IV (0.48 MBq) was carried out. Thirty minutes later, kidney, heart, lung, thyroid, stomach, bladder and femur and samples of blood were isolated. The organs were weighed, counted and the percentage of radioactivity /g (%ATI/g) determined. Serum urea and creatinine, hematocrit, leukocytes and platelets were measured. Statistics by t test (p<0.05) was done. There was a significant reduction in %ATI/g in kidney and blood (p<0.05) of splenectomized animals, a significant increase (p<0.05) of urea (88.8 {+-} 18.6 mg/dL) and creatinine (0.56 {+-} 0.08 mg/dL), compared to the controls (51.5{+-}1.6, 0.37{+-}0.02 mg/dL, respectively), as well as increase in platelets and leucocytes, and hematocrit reduction. The analysis of the results indicates that in rats, splenectomy seems to alter the renal function and the uptake of 99mTc-DMSA. (author)

  18. In vivo study of ALA PLGA nanoparticles-mediated PDT for treating cutaneous squamous cell carcinoma

    Science.gov (United States)

    Wang, Xiaojie; Shi, Lei; Huang, Zheng; Wang, Xiuli

    2014-09-01

    Background: Squamous cell carcinoma (SCC) is a common skin cancer and its treatment is still a challenge. Although topical photodynamic therapy (PDT) is effective for treating in situ and superficial SCC, the effectiveness of topical ALA delivery to thick SCC can be limited by its bioavailability. Polylactic-co-glycolic acid nanopartieles (PLGA NPs) might provide a promising ALA delivery strategy. The aim of this study was to evaluate the efficacy of ALA PLGA NPs PDT for the treatment of cutaneous SCC in a mouse model. Methods: ALA loaded PLGA NPs were prepared and characterized. The therapeutic efficacy of ALA PLGA NP mediated PDT in treating UV-induced cutaneous SCC in the mice model were examined. Results: In vivo study showed that ALA PLGA NPs PDT were more effective than free ALA of the same concentration in treating mouse cutaneous SCC. Conclusion: ALA PLGA NPs provides a promising strategy for delivering ALA and treating cutaneous SCC.

  19. Fabrication of functional PLGA-based electrospun scaffolds and their applications in biomedical engineering.

    Science.gov (United States)

    Zhao, Wen; Li, Jiaojiao; Jin, Kaixiang; Liu, Wenlong; Qiu, Xuefeng; Li, Chenrui

    2016-02-01

    Electrospun PLGA-based scaffolds have been applied extensively in biomedical engineering, such as tissue engineering and drug delivery system. Due to lack of the recognition sites on cells, hydropholicity and single-function, the applications of PLGA fibrous scaffolds are limited. In order to tackle these issues, many works have been done to obtain functional PLGA-based scaffolds, including surface modifications, the fabrication of PLGA-based composite scaffolds and drug-loaded scaffolds. The functional PLGA-based scaffolds have significantly improved cell adhesion, attachment and proliferation. Moreover, the current study has summarized the applications of functional PLGA-based scaffolds in wound dressing, vascular and bone tissue engineering area as well as drug delivery system. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The valuation of 99Tcm-DMSA renal cortical scintigraphy for prediction of renal scarring in children with acute pyelonephritis

    International Nuclear Information System (INIS)

    Zhao Ruifang; Ji Zhiying; Lv Xiaomei; Wu Ha; Li Yiwei; Gu Fanlei; Zhao Xiaofei

    2009-01-01

    Objective: Acute pyelonephritis (APN) is a common infectious disease in childhood. APN may result in ineversible renal scarring. 99 Tc m -dimercaptsuccinic (DMSA) renal cortical scintigraphy was reported to be highly sensitive and specific for detection APN and renal scarring. The aim of this study was to determine the incidence of renal scarring in a group of children with APN and to evaluate the relative factors at risk of scarring using 99 Tc m -DMSA renal cortical scintigraphy. Methods: One hundred and eighteen patients (44 males, 74 females, age range: 1 month to 14 years) with APN underwent DMSA renal cortical scan before treatment and six month after treatment to identify renal damage and renal scarring. The degree of renal damage was divided to grade I to IV. A directed radionuclide cystography (DRC) was performed in 72 cases to evaluate vesicoureteric reflux (VUR). Statistical analysis between all those relative factors was performed using Spearman grading relational analysis. The software was SPSS 11.5. Results: The follow-up renal cortical scan revealed that 79 normal kidneys on first scan remained normal; of 64 kidneys with grade I damage, 7.81% (5/64) developed renal scar; of 51 kidneys with grade II, 49.02% (25/51) developed renal scar; of 19 with grade III, 68.42% (13/19) developed renal scar; of 23 with grade IV, 100.00% (23/23) developed renal scar. There was a significant relationship between the incidence of renal scar on follow-up and the grade of renal damage on first scan (r=0.877, P<0.01). VUR was found in 54.17% (78/144) per renal unit. Only 4.55% (3/66) of those with non-refluxing ureters developed renal scars on follow-up. One of four patients with mild-refluxing ureters developed renal scars. 46.51% (20/43) of those with moderate-refluxing ureters developed renal scars. 87.10% (27/31) of those with severe-refluxing ureters developed renal scars. There was a significant relationship between the incidence of renal scarring in follow-up and

  1. Role of Tc-99M(V) DMSA for imaging of ocular melanoma developing in graves' patients treated with radioiodine

    International Nuclear Information System (INIS)

    Bandopadhyaya, G.P.; Barai, S.; Bal, C.S.

    2004-01-01

    The melanoma originates from the melanocytes, which are embryologically derived from neural crest. The melanoma of choroids in adults is a very common type primary ocular malignancy, where the tyrosine, an immediate precursor common for both melanin and thyroid hormone synthesis is involved. The neurogenic origins of melanoma and medullary thyroid carcinoma have also been shown to have certain common metabolites, receptors and the receptor binding proteins. Several radiolabelled derivatives either in the form of melanin metabolites or melanin binding agents including receptors/ receptor-binding proteins like somatostatin, calcitonin and other monoclonal antibodies, protein receptors (S-100, myelin basic protein, Leu-7, glial fibrillary acidic protein, HMB-45) etc. have been tried to evaluate/diagnose melanoma, staging or post therapeutic effects. However their cost of production, tedious synthetic and radiolabelling processes and the availability of certain cyclotron produced isotopes were not favorable or patient friendly. Moreover post-therapeutic assessments in melanoma patients were not encouraging. Because of the chelating properties of Tc-99m (V) Dimercaptosuccinic acid with Calcium ion, uptake by neurogenic tumors including ocular retinoblastoma, medullary thyroid carcinoma, pituitary adenoma etc has been demonstrated. Since MTC and Melanoma have the common neural crest origin and producing some common metabolites, receptors/receptor proteins and at the same time Tc-99m (V) DMSA was used in pre and post therapeutic assessment of Medullary thyroid carcinoma extensively. We therefore decided to use Tc-99m (v) DMSA for the assessment of melanoma developed in thyrotoxicosis patients who underwent radioiodine therapy more than 15 years back. The DMSA kits were prepared locally and labeled with Tecnetium-99m at pentavalent state. After the quality control each patients were injected a dose of 10mCi of Tc-99m labeled DMSA.The whole body images were taken after two

  2. Progress in Preparation of Monodisperse Polymer Microspheres

    Science.gov (United States)

    Zhang, Hongyan

    2017-12-01

    The monodisperse crosslinked polymer microspheres have attracted much attention because of their superior thermal and solvent resistance, mechanical strength, surface activity and adsorption properties. They are of wide prospects for using in many fields such as biomedicine, electronic science, information technology, analytical chemistry, standard measurement and environment protection etc. Functional polymer microspheres prepared by different methods have the outstanding surface property, quantum size effect and good potential future in applications with its designable structure, controlled size and large ratio of surface to volume. Scholars of all over the world have focused on this hot topic. The preparation method and research progress in functional polymer microspheres are addressed in the paper.

  3. Development of membranes of PLGA functionalized with antimicrobial agents nanostructured

    International Nuclear Information System (INIS)

    Souza, S.G.; Molin, M.L.A.L.; Nogueira, A.L.; Schneider, E. Duek; Pezzin, A.P.T.

    2016-01-01

    Periodontitis is a disease affecting the tooth supporting tissues, causing loss of bone attachment. One of the possible treatments is through guided tissue regeneration (GTR). Currently, a variety of resorbable membranes are available as alternative to conventional non-resorbable membranes for this application, as the membranes of poly (lactic acid-co-glycolic acid) (PLGA). In this context, this study aimed to produce membranes were biocompatible and nanostructured functionalized with antibacterial agents and evaluate its thermal properties for future application in RTG. For the production of membranes were used as the PLGA polymer matrix. The NpAg were used at concentrations of 5, 7, 8 and 10 ppm and NpZnO were: 10, 50, 100 and 150 ppm. The materials were characterized by TGA and DSC. (author)

  4. Pharmacokinetics, biodistribution and dosimetry of sup 99 Tc sup m (V)DMSA in humans with squamous cell carcinoma. [Dimercaptosuccinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Watkinson, J.C.; Allen, S.; Lazarus, C.R.; Sinclair, J.; Blake, G.M.; Clarke, S.E.M. (Guy' s Hospital, London (UK))

    1990-05-01

    Technetium-99m ({sup 99}Tc{sup m})(V) dimercaptosuccinic acid (DMSA) is a new tumour imaging agent which has been used to evaluate squamous carcinoma (SCC) of the head and neck. This study evaluated the pharmacokinetics and biodistribution of {sup 99}Tc{sup m}(V)DMSA in patients with SCC and calculated the bone mass of a New Zealand White (NZW) rabbit. This data was then used to calculate the effective dose equivalent in man. A total of 16 patients were studied (5 with no tumour, 11 with tumour). {sup 99}Tc{sup m}(V)DMSA had a fast bi-exponential blood clearance in patients with no tumour (30 and 401 min) and patients with tumour (30 and 387 min) with no significant difference (p > 0.05) between the two groups. {sup 99}Tc{sup m}(V)DMSA had a fast cumulative urine excretion with mean half-times in non-tumour and tumour patients of 183 min and 244 min respectively. There was no significant difference (p > 0.05) between these two latter groups. The effective dose equivalent of {sup 99}Tc{sup m}(V)DMSA in man is 5.1 {mu}Sv/MBq. (author).

  5. Role of 188Re(V)DMSA in the diagnosis and therapy of medullary thyroid carcinoma: a pilot study in an animal model

    International Nuclear Information System (INIS)

    Learoyd, D.L.; Roach, P.J.; Snowdon, G.M.; Dadachova, K.; Moreau, A.M.; Robinson, B.G.

    1999-01-01

    Full text: 99 Tc m (V)DMSA has been reported to be highly sensitive in the diagnosis of medullary thyroid cancer (MTC). Rhenium-188, a beta emitter, has potential for therapy of MTC. However, initial studies with 188 Re indicate high renal uptake which may interfere with potential therapeutic applications of this radiopharmaceutical. A modified radiolabelling method has been shown to reduced the renal uptake of 188 Re(V)DMSA in control animals. The aims of this study were to determine whether there is uptake of modified 188 Re(V)DMSA in nude mice injected with an MTC cell line and whether there is potential for MTC therapy. Two groups of mice were injected in the left flank (SC) with TT cell line, and in mice showing tumour growth a low-dose (400 kBq) of 188 Re(V)DMSA was injected via a tail vein 8 weeks later. Biodistribution was performed on several mice and several others were given 'therapy' injections (8 MBq) to determine whether tumour shrinkage could be objectively observed. Tracer uptake was highest in bone and kidneys but tumour uptake was relatively low. However, no new tumour growth was seen in any of the mice subsequent to therapy injections and 1 mouse showed complete remission within 5 weeks of injection. Further animal and human studies will need to be performed to determine the potential role of this modified 118 Re(V)DMSA in patients with MTC

  6. Analysis of Ultrasonographic Findings in Children with Urinary Tract Infection : Comparison with Voiding Cystourethrography and 99mTc-DMSA Scan

    International Nuclear Information System (INIS)

    Kim, Mi Yong; Suh, Chang Hae

    1996-01-01

    To evaluate whether the presence of hydronephrosis or cortical irregularity on ultrasonogram (US) in children with urinary tract infection (UTI) predicts the vesicoureteral reflux on voiding cystourethrography(VCUG) or or associated renal scar on DMSA scan, and to assess the clinical value of US. We analyzed 90 kidneys of 45 children with UTI, and US, VCUG and DMSA scan were performed in all cases. We evaluated the presence of hydroneprhosis and cortical irregularity on US, vesicoureteral reflux on VCUG and cortical defect on DMSA scan. We analyzed the sensitivity, specificity and positive and negative predictive values of US findings for detection of vesicoureteral reflux and cortical defect. Hydronephrosis on US showed 28% sensitivity for diagnosis of vesicoureteral reflux on VCUG, and was not significantly related with the grade of reflux.Cortical irregularity on US showed 31% sensitivity and 89% positive predictive value for cortical defect on DMSA scan. Hydronephrosis and cortical irregularity on US showed low sensitivities for diagnosis of refluxon VCUG and cortical defect on DMSA scan, however, ultrasonographic features of renal parenchyma were considered to be useful for prediction of renal scar

  7. Evaluation of Controlled Release Theophylline Microspheres ...

    African Journals Online (AJOL)

    Erah

    High drug/polymer ratio, low processing temperature and low HLB value of ... Keywords: Microsphere, Emulsion solvent evaporation, Theophylline, Temperature, ... evaporation, stirring rate, viscosity of ... organic solvent is removed from the.

  8. Development of membranes of PLGA functionalized with antimicrobial agents nanostructured; Desenvolvimento de membranas de PLGA funcionalizadas com agentes antimicrobianos nanoestruturados

    Energy Technology Data Exchange (ETDEWEB)

    Souza, S.G.; Molin, M.L.A.L.; Nogueira, A.L.; Schneider, E. Duek; Pezzin, A.P.T., E-mail: suelengdesouza@gmail.com [Universidade da Regiao de Joinville (UNIVILLE), SC (Brazil)

    2016-07-01

    Periodontitis is a disease affecting the tooth supporting tissues, causing loss of bone attachment. One of the possible treatments is through guided tissue regeneration (GTR). Currently, a variety of resorbable membranes are available as alternative to conventional non-resorbable membranes for this application, as the membranes of poly (lactic acid-co-glycolic acid) (PLGA). In this context, this study aimed to produce membranes were biocompatible and nanostructured functionalized with antibacterial agents and evaluate its thermal properties for future application in RTG. For the production of membranes were used as the PLGA polymer matrix. The NpAg were used at concentrations of 5, 7, 8 and 10 ppm and NpZnO were: 10, 50, 100 and 150 ppm. The materials were characterized by TGA and DSC. (author)

  9. Direct monophasic replacement of fatty acid by DMSA on SPION surface

    Energy Technology Data Exchange (ETDEWEB)

    Gogoi, M. [Department of Physics, Tezpur University (Central University), Tezpur 784028 (India); Deb, P., E-mail: pdeb@tezu.ernet.in [Department of Physics, Tezpur University (Central University), Tezpur 784028 (India); Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Duesseldorf (Germany); Vasan, G.; Keil, P.; Kostka, A.; Erbe, A. [Interface Chemistry and Surface Engineering, Max-Planck-Institut fuer Eisenforschung GmbH, Max-Planck-Strasse 1, 40237 Duesseldorf (Germany)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Monophasic replacement of fatty acid coating. Black-Right-Pointing-Pointer Ultrastable dispersion of hydrophilic SPION in a wide pH range. Black-Right-Pointing-Pointer Unaltered microstructure and property on surface modification. - Abstract: Tailoring the surface and understanding the surface characteristics is necessary for biomedical applications of superparamagnetic nanoparticles. In this paper, superparamagnetic iron oxide nanoparticles (SPIONs) were prepared by thermal decomposition of iron nitrate in presence of stearic acid as surfactant. Due to the multilayer organization of surfactant molecules over the nanoparticle surface, the surface potential can be tuned by pH changes and hence the nanoparticles can be made dispersible in nonpolar as well as in polar solvents. We have presented a simple, facile procedure for controlled replacement of stearic acid from maghemite surface and subsequent derivatization by biocompatible dimercaptosuccinic acid (DMSA) to obtain ultrastable hydrophilic nanoparticles with unaltered morphology, phase and properties. The surface chemistry of the functionalized SPIONs was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) revealing the presence of bound and unbound thiol groups and disulfides, leading to its prolonged stability in aqueous medium. The consequence of spatially selective functionalization on the stability and solubility of surface hydrophilic SPION has also been realized.

  10. Evaluation of DMSA scintigraphy and urography in assessing both acute and permanent renal damage in children

    Energy Technology Data Exchange (ETDEWEB)

    Stokland, E.; Jacobsson, B. [Dept. of Pediatric Radiology, Sahlgrenska Univ. Hospital, Goeteborg Univ. (Sweden).; Hellstroem, M. [Dept. of Radiology, Sahlgrenska Univ. Hospital, Goeteborg Univ. (Sweden); Jodal, U. [Dept. of Pediatrics, Sahlgrenska Univ. Hospital, Goeteborg Univ. (Sweden); Sixt, R. [Dept. of Pediatric Clinical Physiology, Sahlgrenska Univ. Hospital, Goeteborg Univ. (Sweden)

    1998-07-01

    Purpose: To evaluate dimercaptosuccinic acid (DMSA) scintigraphy and urography in the detection of renal involvement in children with urinary tract infection (UTI) in order to identify patients with a high risk of developing renal damage. Material and Methods: A total of 157 children (median age 0.4 years, range 5 days to 5.8 years) with first-time symptomatic UTI were examined scintigraphy (with an assessment of renal area involvement) and urography at the time of UTI and 1 year later. All evaluations were made blindly. Results: Of the total 314 kidneys, 80 (25%) were abnormal at initial scintigraphy. Of these 80 kidneys, 44 (55%) had normalized at follow-up. Of the 234 initially normal kidneys, 29 (12%) were abnormal at follow-up. One year after UTI, abnormalities were seen in 59 children at scintigraphy and in 18 children at urography. Renal area involvement was larger and split function abnormalities more common in kidneys that were abnormal at both scintigraphy and urography than in kidneys with only scintigraphic abnormalities. Conclusion: Quantitation of renal area involvement and split renal function at early scintigraphy would seem to be useful in identifying patients at risk of developing renal damage. Urography at 1 year after infection identified mainly those with the most severe scintigraphic abnormalities. The clinical importance of scintigraphic abnormalities that are not confirmed by urography is not known. (orig.)

  11. Modeling the effect of succimer (DMSA; dimercaptosuccinic acid) chelation therapy in patients poisoned by lead.

    Science.gov (United States)

    van Eijkeren, Jan C H; Olie, J Daniël N; Bradberry, Sally M; Vale, J Allister; de Vries, Irma; Clewell, Harvey J; Meulenbelt, Jan; Hunault, Claudine C

    2017-02-01

    Kinetic models could assist clinicians potentially in managing cases of lead poisoning. Several models exist that can simulate lead kinetics but none of them can predict the effect of chelation in lead poisoning. Our aim was to devise a model to predict the effect of succimer (dimercaptosuccinic acid; DMSA) chelation therapy on blood lead concentrations. We integrated a two-compartment kinetic succimer model into an existing PBPK lead model and produced a Chelation Lead Therapy (CLT) model. The accuracy of the model's predictions was assessed by simulating clinical observations in patients poisoned by lead and treated with succimer. The CLT model calculates blood lead concentrations as the sum of the background exposure and the acute or chronic lead poisoning. The latter was due either to ingestion of traditional remedies or occupational exposure to lead-polluted ambient air. The exposure duration was known. The blood lead concentrations predicted by the CLT model were compared to the measured blood lead concentrations. Pre-chelation blood lead concentrations ranged between 99 and 150 μg/dL. The model was able to simulate accurately the blood lead concentrations during and after succimer treatment. The pattern of urine lead excretion was successfully predicted in some patients, while poorly predicted in others. Our model is able to predict blood lead concentrations after succimer therapy, at least, in situations where the duration of lead exposure is known.

  12. Evaluation of DMSA scintigraphy and urography in assessing both acute and permanent renal damage in children

    International Nuclear Information System (INIS)

    Stokland, E.; Jacobsson, B.; Jodal, U.; Sixt, R.

    1998-01-01

    Purpose: To evaluate dimercaptosuccinic acid (DMSA) scintigraphy and urography in the detection of renal involvement in children with urinary tract infection (UTI) in order to identify patients with a high risk of developing renal damage. Material and Methods: A total of 157 children (median age 0.4 years, range 5 days to 5.8 years) with first-time symptomatic UTI were examined scintigraphy (with an assessment of renal area involvement) and urography at the time of UTI and 1 year later. All evaluations were made blindly. Results: Of the total 314 kidneys, 80 (25%) were abnormal at initial scintigraphy. Of these 80 kidneys, 44 (55%) had normalized at follow-up. Of the 234 initially normal kidneys, 29 (12%) were abnormal at follow-up. One year after UTI, abnormalities were seen in 59 children at scintigraphy and in 18 children at urography. Renal area involvement was larger and split function abnormalities more common in kidneys that were abnormal at both scintigraphy and urography than in kidneys with only scintigraphic abnormalities. Conclusion: Quantitation of renal area involvement and split renal function at early scintigraphy would seem to be useful in identifying patients at risk of developing renal damage. Urography at 1 year after infection identified mainly those with the most severe scintigraphic abnormalities. The clinical importance of scintigraphic abnormalities that are not confirmed by urography is not known. (orig.)

  13. Modification of PLGA nanoparticles for improved properties as a 99mTc-labeled agent in sentinel lymph node detection.

    Science.gov (United States)

    Subramanian, Suresh; Pandey, Usha; Gugulothu, Dalapathi; Patravale, Vandana; Samuel, Grace

    2013-10-01

    We have earlier reported on the possible application of poly [lactide (co-glycolide)] (PLGA) nanoparticles of suitable size to serve as a (99m)Tc-labeled diagnostic tracer in sentinel lymph node detection (SLND). Additional efforts have now been made to improve both the radiolabeling yield and the biological efficacy by modifying the PLGA particles. Two approaches were taken, one based on in situ loading of mebrofenin inside PLGA nanoparticles and the second one based on functionalization of existing terminal carboxylic acid groups on the nanoparticle surface with p-aminobenzyl diethylenetriamine pentaacetic acid (p-NH2-Bz-DTPA) for enhanced availability of functional groups suitable for (99m)Tc complexation. The modified PLGA derivatives were purified and characterized. Radiolabeling of the modified PLGA nanoparticles was carried out with (99m)Tc using stannous chloride as the reducing agent. Mebrofenin encapsulated PLGA nanoparticles (mebrofenin-PLGA) did not show any significant improvement in the radiolabeling yield in comparison to the earlier reported "plain" PLGA nanoparticles, probably due to inaccessibility of the mebrofenin moiety to (99m)Tc upon encapsulation. DTPA-conjugated PLGA nanoparticles (DTPA-PLGA) showed appreciable improvement in radiolabeling yield under more moderate reaction conditions and better stability. In the biological evaluation performed in Wistar rat model, (99m)Tc-DTPA-PLGA nanoparticles showed a considerable increase in uptake in the sentinel node and the percentage popliteal extraction of the preparation was also higher. (99m)Tc-mebrofenin-PLGA did not show any improvement in SLN uptake over plain PLGA nanoparticles. The above results suggest that surface modification of PLGA by covalently coupling DTPA to PLGA nanoparticles prior to (99m)Tc labeling appears to be a superior approach to achieve a suitable (99m)Tc-labeled PLGA nanoparticle preparation for SLND.

  14. PLGA nanoparticles loaded with host defense peptide LL37 promote wound healing.

    Science.gov (United States)

    Chereddy, Kiran Kumar; Her, Charles-Henry; Comune, Michela; Moia, Claudia; Lopes, Alessandra; Porporato, Paolo E; Vanacker, Julie; Lam, Martin C; Steinstraesser, Lars; Sonveaux, Pierre; Zhu, Huijun; Ferreira, Lino S; Vandermeulen, Gaëlle; Préat, Véronique

    2014-11-28

    Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Poly (lactic-co-glycolic acid) (PLGA) supplies lactate that accelerates neovascularization and promotes wound healing. LL37 is an endogenous human host defense peptide that modulates wound healing and angiogenesis and fights infection. Hence, we hypothesized that the administration of LL37 encapsulated in PLGA nanoparticles (PLGA-LL37 NP) promotes wound closure due to the sustained release of both LL37 and lactate. In full thickness excisional wounds, the treatment with PLGA-LL37 NP significantly accelerated wound healing compared to PLGA or LL37 administration alone. PLGA-LL37 NP-treated wounds displayed advanced granulation tissue formation by significant higher collagen deposition, re-epithelialized and neovascularized composition. PLGA-LL37 NP improved angiogenesis, significantly up-regulated IL-6 and VEGFa expression, and modulated the inflammatory wound response. In vitro, PLGA-LL37 NP induced enhanced cell migration but had no effect on the metabolism and proliferation of keratinocytes. It displayed antimicrobial activity on Escherichia coli. In conclusion, we developed a biodegradable drug delivery system that accelerated healing processes due to the combined effects of lactate and LL37 released from the nanoparticles. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Microporous silk fibroin scaffolds embedding PLGA microparticles for controlled growth factor delivery in tissue engineering.

    Science.gov (United States)

    Wenk, Esther; Meinel, Anne J; Wildy, Sarah; Merkle, Hans P; Meinel, Lorenz

    2009-05-01

    The development of prototype scaffolds for either direct implantation or tissue engineering purposes and featuring spatiotemporal control of growth factor release is highly desirable. Silk fibroin (SF) scaffolds with interconnective pores, carrying embedded microparticles that were loaded with insulin-like growth factor I (IGF-I), were prepared by a porogen leaching protocol. Treatments with methanol or water vapor induced water insolubility of SF based on an increase in beta-sheet content as analyzed by FTIR. Pore interconnectivity was demonstrated by SEM. Porosities were in the range of 70-90%, depending on the treatment applied, and were better preserved when methanol or water vapor treatments were prior to porogen leaching. IGF-I was encapsulated into two different types of poly(lactide-co-glycolide) microparticles (PLGA MP) using uncapped PLGA (50:50) with molecular weights of either 14 or 35 kDa to control IGF-I release kinetics from the SF scaffold. Embedded PLGA MP were located in the walls or intersections of the SF scaffold. Embedment of the PLGA MP into the scaffolds led to more sustained release rates as compared to the free PLGA MP, whereas the hydrolytic degradation of the two PLGA MP types was not affected. The PLGA types used had distinct effects on IGF-I release kinetics. Particularly the supernatants of the lower molecular weight PLGA formulations turned out to release bioactive IGF-I. Our studies justify future investigations of the developed constructs for tissue engineering applications.

  16. Neurotensin-loaded PLGA/CNC composite nanofiber membranes accelerate diabetic wound healing.

    Science.gov (United States)

    Zheng, Zhifang; Liu, Yishu; Huang, Wenhua; Mo, Yunfei; Lan, Yong; Guo, Rui; Cheng, Biao

    2018-04-13

    Diabetic foot ulcers (DFUs) are a threat to human health and can lead to amputation and even death. Recently neurotensin (NT), an inflammatory modulator in wound healing, was found to be beneficial for diabetic wound healing. As we demonstrated previously, polylactide-polyglycolide (PLGA) and cellulose nanocrystals (CNCs) (PLGA/CNC) nanofiber membranes show good cytocompatibility and facilitate fibroblast adhesion, spreading and proliferation. PLGA/CNC nanofiber membranes are novel materials that have not been used previously as NT carriers in diabetic wounds. This study aims to explore the therapeutic efficacy and possible mechanisms of NT-loaded PLGA/CNC nanofiber membranes in full-thickness skin wounds in spontaneously diabetic mice. The results showed that NT could be sustained released from NT-loaded PLGA/CNC composite nanofiber membranes for 2 weeks. NT-loaded PLGA/CNC composite nanofiber membranes induced more rapid healing than other control groups. After NT exposure, the histological scores of the epidermal and dermal regeneration and the ratios of the fibrotic area to the whole area were increased. NT-loaded PLGA/CNC composite nanofiber membranes also decreased the expressions of the inflammatory cytokines IL-1β and IL-6. These results suggest that NT-loaded PLGA/CNC composite nanofiber membranes for sustained delivery of NT should effectively promote tissue regeneration for the treatment of DFUs.

  17. Preclinical Development and In Vivo Efficacy of Ceftiofur-PLGA Microparticles

    Science.gov (United States)

    Vilos, Cristian; Velasquez, Luis A.; Rodas, Paula I.; Zepeda, Katherine; Bong, Soung-Jae; Herrera, Natalia; Cantin, Mario; Simon, Felipe; Constandil, Luis

    2015-01-01

    Drug delivery systems based on polymeric microparticles represent an interesting field of development for the treatment of several infectious diseases for humans and animals. In this work, we developed PLGA microparticles loaded with ceftiofur (PLGA-cef), a third- generation cephalosporin that is used exclusively used in animals. PLGA-cef was prepared by the double emulsion w/o/w method, and exhibited a diameter in the range of 1.5–2.2 μm, and a negative ζ potential in the range of -35 to -55 mV. The loading yield of PLGA-cef was ~7% and encapsulation efficiency was approximately 40%. The pharmacokinetic study demonstrated a sustained release profile of ceftiofur for 20 days. PLGA-cef administrated in a single dose was more effective than ceftiofur non-encapsulated in rats challenged with S. Typhimurium. The in vivo toxicological evaluation showed that PLGA-cef did not affect the blood biochemical, hematological and hemostasis parameters. Overall, the PLGA-cef showed slow in vivo release profile, high antibacterial efficacy, and low toxicity. The results obtained supports the safe application of PLGA-cef as sustained release platform in the veterinary industry. PMID:25915043

  18. Magnetic poly(lactide-co-glycolide) (PLGA) and cellulose particles for MRI-based cell tracking

    Science.gov (United States)

    Nkansah, Michael K.; Thakral, Durga; Shapiro, Erik M.

    2010-01-01

    Biodegradable, superparamagnetic micro- and nanoparticles of poly(lactide-co-glycolide) (PLGA) and cellulose were designed, fabricated and characterized for magnetic cell labeling. Monodisperse nanocrystals of magnetite were incorporated into micro- and nanoparticles of PLGA and cellulose with high efficiency using an oil-in-water single emulsion technique. Superparamagnetic cores had high magnetization (72.1 emu/g). The resulting polymeric particles had smooth surface morphology and high magnetite content (43.3 wt% for PLGA and 69.6 wt% for cellulose). While PLGA and cellulose nanoparticles displayed highest r2* values per millimole of iron (399 s-1mM-1 for cellulose and 505 s-1mM-1 for PLGA), micron-sized PLGA particles had a much higher r2* per particle than either. After incubation for a month in citrate buffer (pH 5.5), magnetic PLGA particles lost close to 50% of their initial r2* molar relaxivity, while magnetic cellulose particles remained intact, preserving over 85% of their initial r2* molar relaxivity. Lastly, mesenchymal stem cells and human breast adenocarcinoma cells were magnetically labeled using these particles with no detectable cytotoxicity. These particles are ideally suited for non-invasive cell tracking in vivo via MRI and due to their vastly different degradation properties, offer unique potential for dedicated use for either short (PLGA-based particles) or long term (cellulose-based particles) experiments. PMID:21404328

  19. NECL1 coated PLGA as favorable conduits for repair of injured peripheral nerve

    International Nuclear Information System (INIS)

    Xu, Fuben; Zhang, Kun; Lv, Peizhen; Lu, Rongbin; Zheng, Li; Zhao, Jinmin

    2017-01-01

    Restoration of normal neurological function of transected peripheral nerve challenged regenerative medicine and surgery. Previous studies showed that Nectin-like molecule 1 (NECL1) is one of the important adhesion molecules on the axons and Schwann cells is located along the internodes in direct apposition to NECL1. In this study, we fabricated PLGA membrane pre-coated with NECL1, mimicking the natural axons to enhance the adhesion of Schwann cells. Investigation of the cellular response in vitro was performed by detecting cytotoxicity, proliferation, morphology, viability, specific markers and Scanning Electron Microscopy (SEM) of Schwann cells cultured in PLGA. Further, the NECL1-coated PLGA conduits were used for peripheral nerve repair after sciatic nerve defect was constructed. Results showed that PLGA-coated NECL1 enhanced cell proliferation compared with PLGA, as evidenced by MTT analysis, cell viability assay and histological evaluation. RT-PCR results showed that GDNF (glial cell line-derived neurotrophic factor), BDNF (brain-derived neurotrophic factor), CNTF (ciliary neurotrophic factor) and neurotrophic factors of axonal regeneration were highly expressed in PLGA/NECL1 group. S100, which is Schwann cell marker, was also elevated in PLGA-NCEL1 in both mRNA and protein expression as demonstrated by PCR and immunohistochemical examination. Moreover, in vivo study showed that implantation of PLGA/NCEL1 tubes in bridging the nerve defect can significantly improve Schwann cell aggregation and attachment and greatly enhance the functional recovery of nerve regeneration as compared with control and PLGA groups. Therefore, the novel blend of PLGA/NECL1 conduits proved to be promising candidate for tissue engineering scaffold. - Highlights: • A fabricated PLGA tubes pre-coated with Nectin-like molecule 1 (NECL1) strategy for sciatic nerve regeneration is proposed. • The NECL1 coated PLGA can promote Schwann cells adhesion and growth meanwhile maintain the

  20. DEGRADATION AND INTRAHEPATIC COMPATIBILITY OF ALBUMIN-HEPARIN CONJUGATE MICROSPHERES

    NARCIS (Netherlands)

    CREMERS, HFM; WOLF, RFE; BLAAUW, EH; SCHAKENRAAD, JM; LAM, KH; NIEUWENHUIS, P; VERRIJK, R; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    The in vitro degradation properties of glutaraldehyde cross-linked albumin and albumin-heparin conjugate microspheres (AMS and AHCMS respectively) were evaluated using light microscopy, turbidity measurements and heparin release determinations, showing that the microspheres are degraded by

  1. Prolonged analgesic effect of PLGA-encapsulated bee venom on formalin-induced pain in rats.

    Science.gov (United States)

    Jeong, Injae; Kim, Beom-Soo; Lee, Hyejung; Lee, Kang-Min; Shim, Insop; Kang, Sung-Keel; Yin, Chang-Shick; Hahm, Dae-Hyun

    2009-10-01

    To enhance the medicinal activity of bee venom (BV) acupuncture, bee venom was loaded into biodegradable poly(D,L-lactide-co-glycolide) nanoparticles (BV-PLGA-NPs) by a water-in-oil-in-water-emulsion/solvent-evaporation technique. Rat formalin tests were performed after subcutaneous injection of BV-PLGA-NPs to the Zusanli acupuncture point (ST36) at 0.5, 1, 2, 6, 12, 24, and 48 h before plantar injection of 2% formalin. BV-PLGA-NPs treatment showed comparable analgesic activity to typical BV acupuncture during the late phase, compared with saline-treated controls, and the analgesic effect lasted for 12h. PLGA-encapsulation was also effective in alleviating the edema induced by allergens in bee venom. These results indicate that PLGA-encapsulation provided a more prolonged effect of BV acupuncture treatment, while maintaining a comparable therapeutic effect.

  2. Urinary tract infection in childhood: lower or upper level? DMSA scintigraphic validation of a new clinical risk index

    International Nuclear Information System (INIS)

    Bayet-Papin, B.; Decomps-Hofmann, A.; Bovier-Lapierre, M.

    2001-01-01

    Urinary tract infection in children can be limited most of time at the lower level of the urinary tractus but an extension to the upper level of the tractus should not be neglected due to the asymptomatic nature of the disease. In our study, we suggest a new graph to predict the probability of acute pyelonephritis only if the bacteriological urinary analyse were obtained in good conditions and without any treatment. In the other cases, a DMSA scintigram should be proposed at the earlier phase of the diagnosis not to underestimate the risk of asymptomatic pyelonephritis. (authors)

  3. CLINICAL STUDIES OF RENAL MORPHOLOGICAL CHANGES WITH AGING - DEMONSTRATING BY USING 99mTc-DMSA SCINTIGRAPHY -

    OpenAIRE

    細川, 進一; 川村, 寿一; 友吉, 唯夫; 吉田, 修

    1980-01-01

    We studied the change of renal shape due to development and aging by using 99mTc-DMSA renal scintigraphy. In pediatric age group, the angle between renal longitudinal axis and the lumbar vertebrae is small but becomes larger with aging. The renal size grows with aging in the adult age group, and becomes largest. In geriatric age group it decreases with aging. The stability of renal position is marked in the adult age group, but in the pediatric and geriatric age group it seemed unstable. Rena...

  4. Fabrication and in vitro biocompatibility of biomorphic PLGA/nHA composite scaffolds for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Junmin, E-mail: jmqian@mail.xjtu.edu.cn; Xu, Weijun; Yong, Xueqing; Jin, Xinxia; Zhang, Wei

    2014-03-01

    In this study, biomorphic poly(DL-lactic-co-glycolic acid)/nano-hydroxyapatite (PLGA/nHA) composite scaffolds were successfully prepared using cane as a template. The porous morphology, phase, compression characteristics and in vitro biocompatibility of the PLGA/nHA composite scaffolds and biomorphic PLGA scaffolds as control were investigated. The results showed that the biomorphic scaffolds preserved the original honeycomb-like architecture of cane and exhibited a bimodal porous structure. The average channel diameter and micropore size of the PLGA/nHA composite scaffolds were 164 ± 52 μm and 13 ± 8 μm, respectively, with a porosity of 89.3 ± 1.4%. The incorporation of nHA into PLGA decreased the degree of crystallinity of PLGA, and significantly improved the compressive modulus of biomorphic scaffolds. The in vitro biocompatibility evaluation with MC3T3-E1 cells demonstrated that the biomorphic PLGA/nHA composite scaffolds could better support cell attachment, proliferation and differentiation than the biomorphic PLGA scaffolds. The localization depth of MC3T3-E1 cells within the channels of the biomorphic PLGA/nHA composite scaffolds could reach approximately 400 μm. The results suggested that the biomorphic PLGA/nHA composite scaffolds were promising candidates for bone tissue engineering. - Highlights: • Novel biomimetic PLGA/nHA composite scaffolds were successfully prepared. • nHA addition improved elastic modulus of PLGA scaffold and decreased its crystallinity. • PLGA/nHA composite scaffolds had better biocompatibility than PLGA scaffolds. • Biomorphic PLGA/nHA composite scaffold had great potential in bone tissue engineering.

  5. Fabrication and in vitro biocompatibility of biomorphic PLGA/nHA composite scaffolds for bone tissue engineering

    International Nuclear Information System (INIS)

    Qian, Junmin; Xu, Weijun; Yong, Xueqing; Jin, Xinxia; Zhang, Wei

    2014-01-01

    In this study, biomorphic poly(DL-lactic-co-glycolic acid)/nano-hydroxyapatite (PLGA/nHA) composite scaffolds were successfully prepared using cane as a template. The porous morphology, phase, compression characteristics and in vitro biocompatibility of the PLGA/nHA composite scaffolds and biomorphic PLGA scaffolds as control were investigated. The results showed that the biomorphic scaffolds preserved the original honeycomb-like architecture of cane and exhibited a bimodal porous structure. The average channel diameter and micropore size of the PLGA/nHA composite scaffolds were 164 ± 52 μm and 13 ± 8 μm, respectively, with a porosity of 89.3 ± 1.4%. The incorporation of nHA into PLGA decreased the degree of crystallinity of PLGA, and significantly improved the compressive modulus of biomorphic scaffolds. The in vitro biocompatibility evaluation with MC3T3-E1 cells demonstrated that the biomorphic PLGA/nHA composite scaffolds could better support cell attachment, proliferation and differentiation than the biomorphic PLGA scaffolds. The localization depth of MC3T3-E1 cells within the channels of the biomorphic PLGA/nHA composite scaffolds could reach approximately 400 μm. The results suggested that the biomorphic PLGA/nHA composite scaffolds were promising candidates for bone tissue engineering. - Highlights: • Novel biomimetic PLGA/nHA composite scaffolds were successfully prepared. • nHA addition improved elastic modulus of PLGA scaffold and decreased its crystallinity. • PLGA/nHA composite scaffolds had better biocompatibility than PLGA scaffolds. • Biomorphic PLGA/nHA composite scaffold had great potential in bone tissue engineering

  6. Biocompatibility of Polyhydroxybutyrate Microspheres: in vitro and in vivo Evaluation

    OpenAIRE

    Shishatskaya, Ekaterina I.; Voinova, Olga N.; Goreva, Anastasya V.; Mogilnaya, Olga A.; Volova, Tatiana G.

    2008-01-01

    Microspheres have been prepared from the resorbable linear polyester of β-hydroxybutyric acid (polyhydroxybutyrate, PHB) by the solvent evaporation technique and investigated in vitro and in vivo. Biocompatibility of the microspheres has been proved in tests in the culture of mouse fibroblast cell line NIH 3Т3 and in experiments on intramuscular implantation of the microspheres to Wistar rats for 3 months. Tissue response to the implantation of polymeric microspheres has been found to consist...

  7. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Z.X.; Zheng, W.; Li, L. [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Zheng, Y.F., E-mail: yfzheng@pku.edu.cn [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China)

    2011-02-15

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: {yields} The average diameter increased with the increase of chitosan content and then decreased. {yields} The release rate of fenbufen increased with the increase of chitosan. {yields} The aligned nanofibrous scaffold exhibits lower drug release rate. {yields} The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which

  8. Fabrication, characterization and in vitro drug release behavior of electrospun PLGA/chitosan nanofibrous scaffold

    International Nuclear Information System (INIS)

    Meng, Z.X.; Zheng, W.; Li, L.; Zheng, Y.F.

    2011-01-01

    Graphical abstract: The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily. Research highlights: → The average diameter increased with the increase of chitosan content and then decreased. → The release rate of fenbufen increased with the increase of chitosan. → The aligned nanofibrous scaffold exhibits lower drug release rate. → The drug release could be controlled by crosslinking in glutaraldehyde vapor. - Abstract: In this study both aligned and randomly oriented poly(D,L-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which would be beneficial

  9. Surface modification of paclitaxel-loaded tri-block copolymer PLGA-b-PEG-b-PLGA nanoparticles with protamine for liver cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Nansha [Chinese Academy of Science, Research Center for Human Tissues and Organs Degeneration, Shenzhen Institute of Advanced Technology (China); Chen, Zhihong [Guangdong Medical College, Analysis Centre (China); Xiao, Xiaojun [Shenzhen University, Institute of Allergy and Immunology, School of Medicine (China); Ruan, Changshun [Chinese Academy of Science, Research Center for Human Tissues and Organs Degeneration, Shenzhen Institute of Advanced Technology (China); Mei, Lin [Tsinghua University, The Shenzhen Key Lab of Gene and Antibody Therapy, and Division of Life and Health Sciences, Graduate School at Shenzhen (China); Liu, Zhigang, E-mail: lzg@szu.edu.cn [Shenzhen University, Institute of Allergy and Immunology, School of Medicine (China); Zeng, Xiaowei, E-mail: zeng.xiaowei@sz.tsinghua.edu.cn [Tsinghua University, The Shenzhen Key Lab of Gene and Antibody Therapy, and Division of Life and Health Sciences, Graduate School at Shenzhen (China)

    2015-08-15

    In order to enhance the therapeutic effect of chemotherapy on liver cancer, a biodegradable formulation of protamine-modified paclitaxel-loaded poly(lactide-co-glycolide)-b-poly(ethylene glycol)-b-poly(lactide-co-glycolide) (PLGA-b-PEG-b-PLGA) nanoparticles (PTX-loaded/protamine NPs) was prepared. Tri-block copolymer PLGA-b-PEG-b-PLGA was synthesized by ring-opening polymerization and characterized by {sup 1}H NMR spectroscopy and gel permeation chromatography. PTX-loaded and PTX-loaded/protamine NPs were characterized in terms of size, size distribution, zeta potential, surface morphology, drug encapsulation efficiency, and drug release. Confocal laser scanning microscopy showed that coumarin 6-loaded/protamine NPs were internalized by hepatocellular carcinoma cell line HepG2. The cellular uptake efficiency of NPs was obviously elevated after protamine modification. With commercial formulation Taxol{sup ®} as the reference, HepG2 cells were also used to study the cytotoxicity of the NPs. PTX-loaded/protamine NPs exhibited significantly higher cytotoxicity than PTX-loaded NPs and Taxol{sup ®} did. All the results suggested that surface modification of PTX-loaded PLGA-b-PEG-b-PLGA NPs with protamine boosted the therapeutic efficacy on liver cancer.

  10. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    ... and characterize indomethacin (IM) microspheres prepared with sugar cane wax microsperes. Methods: Microspheres were prepared by melt-emulsified dispersion and cooling-induced solidification method. The microspheres were characterized by scanning electron microscopy (SEM) and differntial scanning calorimetry ...

  11. Preparation of polymer microspheres by radiation-induced polymerization

    International Nuclear Information System (INIS)

    Naka, Y.; Yamamoto, Y.; Yoshida, Y.; Tagawa, S.

    1995-01-01

    Cross-liking monomer, diethylene glycol dimethacrylate gives microspheres from organic solution by radiation-induced polymerization. /One of the remarkable result is that the number of the microspheres is not changing during the polymerization. Ethyl methacrylate, maleic anhydride, styrene and acrylamide are used as comonomers. These comonomers give the microspheres in the range of 0 to 0.4 as mol fractions. (author)

  12. Low temperature gamma sterilization of a bioresorbable polymer, PLGA

    Science.gov (United States)

    Davison, Lisa; Themistou, Efrosyni; Buchanan, Fraser; Cunningham, Eoin

    2018-02-01

    Medical devices destined for insertion into the body must be sterilised before implantation to prevent infection or other complications. Emerging biomaterials, for example bioresorbable polymers, can experience changes in their properties due to standard industrial sterilization processes. Gamma irradiation is one of the most reliable, large scale sterilization methods, however it can induce chain scission, cross-linking or oxidation reactions in polymers. sterilization at low temperature or in an inert atmosphere has been reported to reduce the negative effects of gamma irradiation. The aim of this study was to investigate the impact of low temperature sterilization (at -80 °C) when compared to sterilization at ambient temperature (25 °C) both in inert atmospheric conditions of nitrogen gas, on poly(lactide co-glycolide) (PLGA). PLGA was irradiated at -80 and 25 °C at 40 kGy in a nitrogen atmosphere. Samples were characterised using differential scanning calorimetry (DSC), tensile test, Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy and gel permeation chromatography (GPC). The results showed that the molecular weight was significantly reduced as was the glass transition temperature, an indication of chain scission. FTIR showed small changes in chemical structure in the methyl and carbonyl groups after irradiation. Glass transition temperature was significantly different between irradiation at -80 °C and irradiation at 25 °C, however this was a difference of only 1 °C. Ultimately, the results indicate that the sterilization temperature used does not affect PLGA when carried out in a nitrogen atmosphere.

  13. Flexible Microsphere-Embedded Film for Microsphere-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Xing, Cheng; Yan, Yinzhou; Feng, Chao; Xu, Jiayu; Dong, Peng; Guan, Wei; Zeng, Yong; Zhao, Yan; Jiang, Yijian

    2017-09-27

    Dielectric microspheres with extraordinary microscale optical properties, such as photonic nanojets, optical whispering-gallery modes (WGMs), and directional antennas, have drawn interest in many research fields. Microsphere-enhanced Raman spectroscopy (MERS) is an alternative approach for enhanced Raman detection by dielectric microstructures. Unfortunately, fabrication of microsphere monolayer arrays is the major challenge of MERS for practical applications on various specimen surfaces. Here we report a microsphere-embedded film (MF) by immersing a highly refractive microsphere monolayer array in the poly(dimethylsiloxane) (PDMS) film as a flexible MERS sensing platform for one- to three-dimensional (1D to 3D) specimen surfaces. The directional antennas and wave-guided whispering-gallery modes (WG-WGMs) contribute to the majority of Raman enhancement by the MFs. Moreover, the MF can be coupled with surface-enhanced Raman spectroscopy (SERS) to provide an extra >10-fold enhancement. The limit of detection is therefore improved for sensing of crystal violet (CV) and Sudan I molecules in aqueous solutions at concentrations down to 10 -7 M. A hybrid dual-layer microsphere enhancer, constructed by depositing a MF onto a microsphere monolayer array, is also demonstrated, wherein the WG-WGMs become dominant and boost the enhancement ratio >50-fold. The present work opens up new opportunities for design of cost-effective and flexible MERS sensing platforms as individual or associated techniques toward practical applications in ultrasensitive Raman detection.

  14. Padronização do método para cálculo da captação renal absoluta do99mTc-DMSA em cria Standardization of a method to calculate absolute renal uptake of 99mTc-DMSA in children

    Directory of Open Access Journals (Sweden)

    Carla Rachel Ono

    2006-02-01

    Full Text Available OBJETIVO: O trabalho teve por objetivo padronizar o método e estabelecer valores normais da captação renal absoluta do99mTc-DMSA em crianças. MATERIAIS E MÉTODOS: Vinte e duas crianças (idade de 7 meses a 10 anos; média de 4,5 anos sem doença renal prévia foram submetidas a cintilografia renal estática com 99mTc-DMSA. Dezoito apresentavam ultra-sonografia, uretrocistografia miccional, "clearance" de creatinina e padrão visual da cintilografia renal estática normais. Quatro crianças foram excluídas por não terem completado ou por apresentarem redução do "clearance" de creatinina. A captação absoluta de DMSA (DMSA-Abs foi calculada como a porcentagem da atividade administrada retida em cada rim após seis horas da administração do radiofármaco. RESULTADOS: Os valores de DMSA-Abs foram de 21,8% ± 3,2% para o rim direito e de 23,1% ± 3,3% para o rim esquerdo. Os valores da captação absoluta não mostraram correlação com a idade dos pacientes estudados, apesar da tendência de aumento do "clearance" de creatinina com a idade. CONCLUSÃO: A definição de valores normais da DMSA-Abs permite o emprego deste parâmetro na avaliação inicial e acompanhamento de doenças renais, principalmente em pacientes com acometimento bilateral ou com rim único (nos quais a função diferencial direita X esquerda tem valor limitado.OBJECTIVE: To standardize a method and determine normal values for absolute renal uptake of 99mTc-DMSA in children with normal creatinine clearance. MATERIALS AND METHODS: Twenty-two children (between 7 months and 10 years of age; mean 4.5 years without clinical evidence of renal disease were studied using 99mTc-DMSA scintigraphy. Eighteen had normal renal ultrasonography, micturating urethrocystography, creatinine clearance and visual interpretation of the scintigraphy with 99mTc-DMSA. Four children were excluded, one with incomplete creatinine clearance and three due to reduction in the creatinine clearance

  15. Preparation, physicochemical properties and biocompatibility of PBLG/PLGA/bioglass composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ning [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Qian, Junmin, E-mail: jmqian@mail.xjtu.edu.cn [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, Jinlei [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China); Ji, Chuanlei [The Orthopaedic Department, XiJing Hospital Affiliated to the Fourth Military Medical University, Xi' an 710032 (China); Xu, Weijun; Wang, Hongjie [State Key Laboratory for Mechanical Behavior of Materials, Xi' an Jiaotong University, Xi' an 710049 (China)

    2017-02-01

    In this study, novel poly(γ-benzyl L-glutamate)/poly(lactic-co-glycolic acid)/bioglass (PBLG/PLGA/BG) composite scaffolds with different weight ratios were fabricated using a negative NaCl-templating method. The morphology, compression modulus and degradation kinetics of the scaffolds were characterized. The results showed that the PBLG/PLGA/BG composite scaffolds with a weight ratio of 5:5:1, namely PBLG5PLGA5BG composite scaffolds, displayed a pore size range of 50–500 μm, high compressive modulus (566.6 ± 8.8 kPa), suitable glass transition temperature (46.8 ± 0.2 °C) and low degradation rate (> 8 weeks). The in vitro biocompatibility of the scaffolds was evaluated with MC3T3-E1 cells by live-dead staining, MTT and ALP activity assays. The obtained results indicated that the PBLG5PLGA5BG composite scaffolds were more conducive to the adhesion, proliferation and osteoblastic differentiation of MC3T3-E1 cells than PBLG and PBLG/PLGA composite scaffolds. The in vivo biocompatibility of the scaffolds was evaluated in both SD rat subcutaneous model and rabbit tibia defect model. The results of H&E, Masson's trichrome and CD34 staining assays demonstrated that the PBLG5PLGA5BG composite scaffolds allowed the ingrowth of tissue and microvessels more effectively than PBLG/PLGA composite scaffolds. The results of digital radiography confirmed that the PBLG5PLGA5BG composite scaffolds significantly improved in vivo osteogenesis. Collectively, the PBLG5PLGA5BG composite scaffolds could be a promising candidate for tissue engineering applications. - Highlights: • Foamy PBLG/PLGA/bioglass composite scaffolds were fabricated by negative templating. • PBLG/PLGA/bioglass composite scaffolds displayed tunable physicochemical properties. • PBLG/PLGA/bioglass composite scaffolds had good biocompatibility in vitro and in vivo. • PBLG/PLGA/bioglass composite scaffolds could promote the healing of bone defects.

  16. Biosensing by WGM Microspherical Resonators

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2016-06-01

    Full Text Available Whispering gallery mode (WGM microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed.

  17. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1995-04-18

    New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for our engineered glass microspheres is about 150,000 psi, permitting a threefold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers.

  18. Study of the biokinetic behavior of 99mTc-DMSA in renal scintigraphy of pediatric patients

    International Nuclear Information System (INIS)

    Santos, Felipe Simas dos

    2013-01-01

    In Brazil, renal studies with 99m Tc D TPA and 99m Tc-DMSA constitute about 18% of pediatric diagnostic procedures. A retrospective non-randomized study was conducted in 2010, for absolute quantification of kidney activities. In 2010,51 patients underwent renal studies in the Hospital of the Rio de Janeiro State University - HUPE-UERJ/ RJ, Brazil. 19 of them with 9±4 years of age and body mass of 31.8±20.8 kg showed relative uptake of 99m Tc-DMSA between 45% and 55%. Still images (AP, PA and posterior oblique abdomen incidences) were acquired 4 h after intravenous administration of 115.69±42.31 MBq of 99m Tc-DMSA using gamma camera (Siemens E-Cam), LEHR collimator, matrix of 256x256 and 5min imaging. In 2012, 3 patients (9.3±2.1 years, 31.97±10.75 kg) in the previous study were followed in a prospective study. All urinary excretions samples were collected from administration of 99m Tc-DMSA to 6 h after, while simultaneously images were acquired AP and PA abdominal region with Philips model Picker Prism 2000XP. Aliquots of each urine sample were measured in gamma counter shaft GenesysTM Gamma 1 with Nal (TI) detector. For whole body, the biological half-life estimate was 11.0±2.0 h, and the residence time was found to be 5.6±0.4 h while the literature suggests 4.l±0.5 h for age range studied. Residence time for kidney was found to be 0.7±0.4 h, while the literature shows, 3.07 h and 1.4 h for patients with normal and renal pathologies, respectively. This difference may be attributed to the methodology because while the images were taken during the first 6 h, SMITH et aI. (1996) performed images of the kidneys and whole body 30 h after administration of 99mTc D MSA, incorporating the slow term of biological half-life. For liver, it was found the average residence time of 3.0±0.4 min, whereas the literature indicates 20.8 min and 25.1 min, respectively according to SMITH et. ai (1996) and ICRP (1998). The fact that the administered activity was higher than

  19. PLGA Nanoparticles for Ultrasound-Mediated Gene Delivery to Solid Tumors

    Directory of Open Access Journals (Sweden)

    Marxa Figueiredo

    2012-01-01

    Full Text Available This paper focuses on novel approaches in the field of nanotechnology-based carriers utilizing ultrasound stimuli as a means to spatially target gene delivery in vivo, using nanoparticles made with either poly(lactic-co-glycolic acid (PLGA or other polymers. We specifically discuss the potential for gene delivery by particles that are echogenic (amenable to destruction by ultrasound composed either of polymers (PLGA, polystyrene or other contrast agent materials (Optison, SonoVue microbubbles. The use of ultrasound is an efficient tool to further enhance gene delivery by PLGA or other echogenic particles in vivo. Echogenic PLGA nanoparticles are an attractive strategy for ultrasound-mediated gene delivery since this polymer is currently approved by the US Food and Drug Administration for drug delivery and diagnostics in cancer, cardiovascular disease, and also other applications such as vaccines and tissue engineering. This paper will review recent successes and the potential of applying PLGA nanoparticles for gene delivery, which include (a echogenic PLGA used with ultrasound to enhance local gene delivery in tumors or muscle and (b PLGA nanoparticles currently under development, which could benefit in the future from ultrasound-enhanced tumor targeted gene delivery.

  20. Ibuprofen induces reduction of the proliferation-seeking radiotracer 99mTc-(V)DMSA uptake in severe epithelial breast hyperplasia without atypia.

    Science.gov (United States)

    Papantoniou, Vassilios; Tsaroucha, Angeliki; Valsamaki, Pipitsa; Tsiouris, Spyridon; Sotiropoulou, Evangelia; Karianos, Theodore; Marinopoulos, Spyridon; Fothiadaki, Athina; Sotiropoulou, Maria; Archontaki, Aikaterini; Syrgiannis, Konstantinos; Dimitrakakis, Konstantinos; Antsaklis, Aris

    2010-10-01

    The purpose of this study was to investigate if ibuprofen intake can influence mammary uptake of the proliferation-seeking radiotracer technetium 99m-pentavalent dimercaptosuccinic acid (99mTc-(V)DMSA) in women with severe epithelial and atypical epithelial breast hyperplasia. Eight patients with histologically confirmed severe epithelial breast hyperplasia with (n  =  4) and without atypia (n  =  4) were submitted prospectively to 99mTc-(V)DMSA scintimammography before and after a 4-week course of 400 mg ibuprofen daily oral intake. Lesion to background ratios 60 minutes postinjection were calculated and compared (t-test) before and after ibuprofen administration. Prior to ibuprofen, the patients with severe epithelial hyperplasia displayed a significantly higher 99mTc-(V)DMSA uptake ratio compared to those with atypical epithelial hyperplasia (2.40 ± 0.32 vs 1.67 ± 0.09, respectively; p  =  .003). They also exhibited a more substantial percent decline in tracer uptake postibuprofen compared to women with atypical epithelial hyperplasia (62.0 ± 7.1 vs 15.0 ± 0.2, respectively; p  =  .001). Ibuprofen induces significant uptake reduction of the proliferation-seeking radiotracer 99mTc-(V)DMSA in severe epithelial breast hyperplasia without atypia. This agent could therefore constitute a potential imaging tool for monitoring chemoprophylaxis effectiveness in women at the early stages of malignant transformation.

  1. Usefulness of the dimercapto succinic pentavalent acid (99m Tc- Dmsa-V) in the diagnostic of the bone metastases illness

    International Nuclear Information System (INIS)

    Ortega L, N.

    2005-01-01

    The objective of this study was to determine the utility of 99m Tc-(V)- Dmsa whole body planar scan in the diagnostic of skeletal metastases. Nineteen patients were studied, having a recent 99m Tc-HDP bone scan reporting different pathologies (3 normal scans, 5 equivocal scans and 11 with disseminated bone metastases). 72 hours later, a whole body planar scan was obtained at 3 and 24 hours after the i.v. administration of 99m Tc-(V)-Dmsa. Counts per pixel were determined in regions of interest drawn over metastases sites and in normal tissue, and were correlated with the bone scan. Statistical analysis was carried out by using the Kruskal-Wallis analysis of variance followed by Mann Whitney U test. Other comparisons were done with Momios, chi square and t Student tests. 273 lesions were studied in the whole body bone scan and 184 lesions in the 99m Tc-(V)-Dmsa scintigraphy (t Student test n.s.). The tumor to normal tissue ratios were 3.3 (+/- 0.521) and the soft to normal tissue ratios were 1.01 (+/- 0.01), Mann Whitney p 99m Tc-(V)-Dmsa scintigraphy is an useful choice in the diagnostic of bone metastases when the whole body planar bone scan ( 99m Tc- HDP) is equivocal or abnormal. It also points out other lesions such as in bone and in soft tissue. (Author)

  2. Role of garlic extract and silymarin compared to dimercaptosuccinic acid (DMSA in treatment of lead induced nephropathy in adult male albino rats

    Directory of Open Access Journals (Sweden)

    Iman A. El-Khishin

    2015-01-01

    Full Text Available Lead poisoning has been known as an important disorder that affects individuals through acute, sub-acute and chronic exposure in environmental and occupational settings. This study was conducted to compare the curative role of garlic combined with silymarin versus dimercaptosuccinic acid (DMSA in decreasing lead induced nephrotoxicity in adult male albino rats. The period of lead intoxication extended for 3 months followed by either 1 month treatment with garlic and silymarin or 5 days treatment with DMSA. Lead poisoning caused non-significant difference in kidney function tests (BUN and serum creatinine while, it caused significant elevation in kidney lead level, significant decrease in renal antioxidant enzyme glutathione peroxidase and significant elevation in kidney malondialdehyde. Histologically, lead induced disorganization and shrinkage of glomeruli with sloughing and vaculation of epithelium, widening of Bowman's space and inflammatory infiltration in renal medulla. Treatment by garlic extract combined with silymarin as well as treatment with DMSA resulted in significant improvement in the affected parameters. Also, both methods of treatment resulted in improvement of the histopathological changes. It can be concluded that garlic extract combined to silymarin is comparable to DMSA in amelioration of lead induced nephrotoxicity.

  3. Antioxidant Effects of Quercetin and Catechin Encapsulated into PLGA Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hector Pool

    2012-01-01

    Full Text Available Polymeric nanoparticles (PLGA have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy and ζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency and in vitro release profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE ≈ 79% and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds. In vitro release profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the polymeric nanoparticles. The inhibition of the action of free radicals and chelating properties, were also enhanced when quercetin and catechin were encapsulated within PLGA nanoparticles. The information obtained from this study will facilitate the design and fabrication of polymeric nanoparticles as possible oral delivery systems for encapsulation, protection and controlled release of flavonoids aimed to prevent oxidative stress in human body or food products.

  4. A microsphere suspension model of metamaterial fluids

    Directory of Open Access Journals (Sweden)

    Qian Duan

    2017-05-01

    Full Text Available Drawing an analogy to the liquid phase of natural materials, we theoretically propose a microsphere suspension model to realize a metamaterial fluid with artificial electromagnetic indexes. By immersing high-ε, micrometer-sized dielectric spheres in a low-ε insulating oil, the structured fluid exhibits liquid-like properties from dispersing phase as well as the isotropic negative electromagnetic parameters caused by Mie resonances from dispersed microspheres. The work presented here will benefit the development of structured fluids toward metamaterials.

  5. Is furosemide administration effective in improving the accuracy of determination of differential renal function by means of technetium-99m DMSA in patients with hydronephrosis

    International Nuclear Information System (INIS)

    Kabasakal, Levent; Turkmen, Cuneyt; Ozmen, Ozlem; Alan, Nalan; Onsel, Cetin; Uslu, Ilhami

    2002-01-01

    It has been suggested that determination of differential renal function (DRF)using technetium-99m dimercaptosuccinic acid (DMSA) may lead to overestimation of the function of an obstructed kidney in patients with excretion abnormalities owing to pelvic retention of DMSA. Recently published guidelines have recommended use of furosemide injection when calculating DRF in these particular patients. The aim of this study was to evaluate the effect of diuretic administration on the determination of DRF using DMSA scintigraphy. For this purpose, 19 patients, aged from 1 month to 69 years (19.4±24.8 years, 15 males, 4 females), in whom pelvic retention had been documented by diuresis scintigraphy were included in the study. DMSA scintigraphy was performed in all patients 2-4 h after injection and six planar images were obtained. Immediately after the standard study, furosemide was injected in all patients, and 30 min later the same number of images was obtained. DRF was calculated for each patient and from each DMSA study by using the arithmetic mean method. The difference between two studies (DMSA scintigraphy with or without furosemide administration and diuresis scintigraphy) was expressed as a percentage of the mean value of the two studies (the DRF value of the affected kidney was thus taken into account). The mean of the differences represented the systemic bias and the SD of the mean of the differences represented the precision of the technique. In seven patients, diuresis renography revealed an obstructive curve pattern. We did not observe any significant difference between the DRF values obtained before and after diuretic administration (P>0.5). When we compared DRF values obtained from standard and from diuretic DMSA studies, the mean of the differences was only 0.3% and the SD was only 1.2%. There was also no significant difference in DRF between patients with the obstructive curve pattern and those with a dilated renogram curve pattern (with washout of

  6. Is furosemide administration effective in improving the accuracy of determination of differential renal function by means of technetium-99m DMSA in patients with hydronephrosis

    Energy Technology Data Exchange (ETDEWEB)

    Kabasakal, Levent; Turkmen, Cuneyt; Ozmen, Ozlem; Alan, Nalan; Onsel, Cetin; Uslu, Ilhami [Department of Nuclear Medicine, Cerrahpasa Medical Faculty, Aksaray Istanbul, 34303 (Turkey)

    2002-11-01

    It has been suggested that determination of differential renal function (DRF)using technetium-99m dimercaptosuccinic acid (DMSA) may lead to overestimation of the function of an obstructed kidney in patients with excretion abnormalities owing to pelvic retention of DMSA. Recently published guidelines have recommended use of furosemide injection when calculating DRF in these particular patients. The aim of this study was to evaluate the effect of diuretic administration on the determination of DRF using DMSA scintigraphy. For this purpose, 19 patients, aged from 1 month to 69 years (19.4{+-}24.8 years, 15 males, 4 females), in whom pelvic retention had been documented by diuresis scintigraphy were included in the study. DMSA scintigraphy was performed in all patients 2-4 h after injection and six planar images were obtained. Immediately after the standard study, furosemide was injected in all patients, and 30 min later the same number of images was obtained. DRF was calculated for each patient and from each DMSA study by using the arithmetic mean method. The difference between two studies (DMSA scintigraphy with or without furosemide administration and diuresis scintigraphy) was expressed as a percentage of the mean value of the two studies (the DRF value of the affected kidney was thus taken into account). The mean of the differences represented the systemic bias and the SD of the mean of the differences represented the precision of the technique. In seven patients, diuresis renography revealed an obstructive curve pattern. We did not observe any significant difference between the DRF values obtained before and after diuretic administration (P>0.5). When we compared DRF values obtained from standard and from diuretic DMSA studies, the mean of the differences was only 0.3% and the SD was only 1.2%. There was also no significant difference in DRF between patients with the obstructive curve pattern and those with a dilated renogram curve pattern (with washout of

  7. Comparison of differential renal function using technetium-99m mercaptoacetyltriglycine (MAG3) and technetium-99m dimercaptosuccinic acid (DMSA) renography in a paediatric population

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, Gillian; Wilkinson, Alistair G. [Royal Hospital for Sick Children, Edinburgh (United Kingdom); Prescott, Robin J. [University of Edinburgh Medical School, Medical Statistics Unit, Public Health Sciences, Edinburgh (United Kingdom)

    2008-08-15

    In children who have undergone both {sup 99m}Tc-DMSA and {sup 99m}Tc-MAG3 studies for the assessment of differential renal function (DRF) and drainage, respectively, we have noticed good agreement between the calculated DRF values, and hypothesized that there is no significant difference in DRF values calculated from these tests. Therefore, both tests may not always be necessary. To determine whether there is a statistically significant difference between DRF values calculated using {sup 99m}Tc-DMSA and those calculated using {sup 99m}Tc-MAG3. We retrospectively identified children imaged with {sup 99m}Tc-DMSA and {sup 99m}Tc-MAG3. We recorded DRF values, age, indication, and renal pelvis diameter. For the {sup 99m}Tc-DMSA studies we recorded the imaging time after injection. For the {sup 99m}Tc-MAG3 studies we recorded the delay between injection and data acquisition, diuretic use and evidence of delayed drainage or reflux. We identified 100 episodes in 92 children where both {sup 99m}Tc-DMSA and {sup 99m}Tc-MAG3 scans had been performed within a few days. The commonest indication was urinary tract infection or pelviureteric junction obstruction. The mean age of the children was 6.96 years. A significant but clinically acceptable trend was seen between abnormal DRF and difference between tests. A significant link was found with the difference between tests and the time of imaging after DMSA injection, and also with scarring. No significant effect was caused by renal pelvis dilatation, delayed drainage, frusemide administration, or delayed {sup 99m}Tc-MAG3 imaging. If a {sup 99m}Tc-MAG3 study has been performed then a {sup 99m}Tc-DMSA study is unnecessary provided DRF is normal on the {sup 99m}Tc-MAG3 study and there is no scarring. A change in practice would lead to considerable savings in time, cost and radiation burden. (orig.)

  8. Albumin microspheres labeled with Ga-67 by chelation: concise communication

    International Nuclear Information System (INIS)

    Hnatowich, D.J.; Schlegel, P.

    1981-01-01

    Albumin microspheres have been synthesized with EDTA and DTPA chelating groups covalently bound to their surface. The microspheres may be labeled with Ga-67 at high yield (97 +- 2%) by transcomplexation from a 0.1 M Ga-67 acetate solution. With EDTA microspheres the resulting label dissociates only slightly after 24 hr in 50% plasma at 37 0 C, whereas with DTPA microspheres the label shows no detectable dissociation over this period. By contrast, microspheres without chelating groups lose their label virtually completely under these conditions. Following intravenous administration of sized Ga-67 DTPA microspheres in mice, about (84 +- 16)% of the activity localizes in the lungs at 5 min, with (60 +- 7)% remaining after 2 h. Since labeling is by chelation, the microspheres may also be tagged with other metallic radionuclides

  9. {sup 99m}Tc-(V)DMSA scintimammography in the assessment of breast lesions: comparative study with {sup 99m}Tc-MIBI

    Energy Technology Data Exchange (ETDEWEB)

    Papantoniou, V.; Papadaki, E.; Valotassiou, V.; Stipsanelli, A.; Zerva, C. [Dept. of Nuclear Medicine, Alexandra University Hospital, Athens (Greece); Christodoulidou, J.; Pampouras, G. [Dept. of Radiology, Alexandra University Hospital, Athens (Greece); Louvrou, A.; Lazaris, D.; Keramopoulos, A.; Michalas, S. [Dept. of Obstetrics and Gynaecology, Alexandra University Hospital, Athens (Greece); Sotiropoulou, M. [Dept. of Pathology, Alexandra University Hospital, Athens (Greece)

    2001-07-01

    The purpose of this study was to evaluate and compare the diagnostic accuracy of pentavalent technetium-99m dimercaptosuccinic acid [{sup 99m}Tc-(V)DMSA] and {sup 99m}Tc-methoxyisobutylisonitrile (MIBI) in the detection of primary breast cancer and metastatic lymph node involvement, and in the clarification of cases with indeterminate mammograms. Forty-one women (mean age{+-}SD 55{+-}7 years) referred for a suspicious breast lesion on physical examination and/or an abnormal mammogram underwent MIBI and (V)DMSA scintimammography (SMM) at separate sessions (48-h interval). Lateral prone and anterior supine images were obtained at 10 and 60 min after administration of 740-925 MBq of each tracer, in the arm contralateral to the breast lesion. The ipsilateral axillary region was also included in the field of view. The results of SMM and mammography were compared with histological findings. Breast cancer was histologically confirmed in 26 patients (mean diameter{+-}SD 2.87{+-}1.5 cm). Benign lesions were found in 15 patients (mean diameter{+-}SD 2.04{+-}2.7 cm). Mammography was definitely positive in 23/26 patients with breast cancer and indeterminate in 3/26 (sensitivity 88.4%). In benign lesions, mammography was true negative in 5/15 cases and indeterminate in 10/15 (specificity 33.3%). Both MIBI and (V)DMSA SMM detected 23/26 breast cancers (sensitivity 88.4%) and were true negative in 14/15 (specificity 93.3%). T/B ratios for breast cancer in MIBI and (V)DMSA scans were similar, and significantly higher than for benign lesions. MIBI correctly diagnosed 12/13 and (V)DMSA 11/13 cases in which the findings of mammography were indeterminate. In addition, (V)DMSA detected seven of eight cases of in situ ductal carcinoma (DCIS) associated with infiltrating carcinomas, while MIBI detected only two of these eight cases. (V)DSMA was also diffusely concentrated in benign lesions complicated by epithelial hyperplasia. Metastatic lymph node involvement was successfully imaged in

  10. In vitro characterisation of PLGA nanoparticles encapsulating rifampicin and isoniazid - Towards IVIVC

    CSIR Research Space (South Africa)

    Booysen, L

    2010-09-01

    Full Text Available .43 15.8 8. 1% PEG-InH 281.1 0.35 67.65 24.8 8.52 9.1%Pluronic-InH 319.5 0.347 69 27.6 13.7 PLGA-rhd(1% PEG) 313.3 0.303 n/A n/A n/A PLGA-rhd(1% PLu) 442.7 0.293 n/A n/A n/A PLGA-poly-(lactic-co-glycolic) acid; PEG-poly ethylene glycol; d...

  11. Combination of calcium sulfate and simvastatin-controlled release microspheres enhances bone repair in critical-sized rat calvarial bone defects

    Directory of Open Access Journals (Sweden)

    Fu YC

    2015-12-01

    Full Text Available Yin-Chih Fu,1–4 Yan-Hsiung Wang,1,5 Chung-Hwan Chen,1,3,4 Chih-Kuang Wang,1,6 Gwo-Jaw Wang,1,3,4 Mei-Ling Ho1,3,7,8 1Orthopaedic Research Center, 2Graduate Institute of Medicine, 3Department of Orthopaedics, 4Department of Orthopaedics, College of Medicine, 5School of Dentistry, College of Dental Medicine, 6Department of Medicinal and Applied Chemistry, 7Department of Physiology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 8Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, TaiwanAbstract: Most allogenic bone graft substitutes have only osteoconductive properties. Developing new strategies to improve the osteoinductive activity of bone graft substitutes is both critical and practical for clinical application. Previously, we developed novel simvastatin-encapsulating poly(lactic-co-glycolic acid microspheres (SIM/PLGA that slowly release simvastatin and enhance fracture healing. In this study, we combined SIM/PLGA with a rapidly absorbable calcium sulfate (CS bone substitute and studied the effect on bone healing in critical-sized calvarial bone defects in a rat model. The cytotoxicity and cytocompatibility of this combination was tested in vitro using lactate dehydrogenase leakage and a cell attachment assay, respectively. Combination treatment with SIM/PLGA and the CS bone substitute had no cytotoxic effect on bone marrow stem cells. Compared with the control, cell adhesion was substantially enhanced following combination treatment with SIM/PLGA and the CS bone substitute. In vivo, implantation of the combination bone substitute promoted healing of critical-sized calvarial bone defects in rats; furthermore, production of bone morphogenetic protein-2 and neovascularization were enhanced in the area of the defect. In summary, the combination of SIM/PLGA and a CS bone substitute has osteoconductive and osteoinductive properties, indicating that it could be used for regeneration

  12. Biological Properties of Low-Toxicity PLGA and PLGA/PHB Fibrous Nanocomposite Implants for Osseous Tissue Regeneration. Part I: Evaluation of Potential Biotoxicity

    Directory of Open Access Journals (Sweden)

    Izabella Krucińska

    2017-11-01

    Full Text Available In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide-co-glycolide (PLGA and syntheticpoly([R,S]-3-hydroxybutyrate, PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes.

  13. Gastroretentive Floating Microspheres of Silymarin: Preparation and ...

    African Journals Online (AJOL)

    Erah

    simulated gastric fluid for at least 12 h, and, therefore, could potentially ... systems (GRFDDS) have a bulk density ... The objective of this work was to develop and characterise gastroretentive floating microspheres of silymarin which, following oral administration, would exhibit .... hydrochloric acid to maintain sink conditions.

  14. Structuring of diamond films using microsphere lithography

    Czech Academy of Sciences Publication Activity Database

    Domonkos, Mária; Ižák, Tibor; Štolcová, L.; Proška, J.; Demo, Pavel; Kromka, Alexander

    2014-01-01

    Roč. 54, č. 5 (2014), s. 320-324 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 Keywords : nanostructuring * diamond thin films * polystyrene microspheres * reactive ion etching * scanning electron microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism

  15. Method and apparatus for producing microspherical particles

    International Nuclear Information System (INIS)

    Egli, W.; Bailey, W.H.; Leary, D.F.; Lansley, R.J.

    1979-01-01

    This invention relates generally to a method and apparatus for producing microspherical particles and more particularly to a method and apparatus which are particularly useful in connection with the sol-gel process for the production of nuclear fuel kernels. (U.K.)

  16. Beat-Frequency/Microsphere Medical Ultrasonic Imaging

    Science.gov (United States)

    Yost, William T.; Cantrell, John H.; Pretlow, Robert A., III

    1995-01-01

    Medical ultrasonic imaging system designed to provide quantitative data on various flows of blood in chambers, blood vessels, muscles, and tissues of heart. Sensitive enough to yield readings on flows of blood in heart even when microspheres used as ultrasonic contrast agents injected far from heart and diluted by circulation of blood elsewhere in body.

  17. Optimization of administered radionuclide activity in renal studies using {sup 9}9mTc -DMSA in Cuba; Optimizacion de actividad a administrar para estudios de gammagrafia renal con {sup 9}9mTc-DMSA en Cuba

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Barreto, M.; Perez Diaz, M.; Lopez Bejerano, G. M.; Varela Corona, C.; Paz Viera, J. E.

    2009-07-01

    The present research is focused on the optimization of administered radionuclide activity in renal studies using {sup 9}9mTc-DMSA. The patients sample included 35 subjects, 23 of them were children and the other 12 were adults. Physical and metabolic characteristics of patients, total time of the study as well as radiopharmaceuticals quality and gamma camera performance was considered in the experiments. Image quality of each study was evaluated using subjective criteria from two expert observers, without previous information about administered activity, and objective criteria based on signal/noise ratios and variance of the random noise in the images. They were used to develop clustering and discriminant analysis over the independent variables to detect groups of images with differentiated quality from the physical and mathematical point of view. As a conclusion, we found that it is possible to reduce the given activities in 50%. (Author) 30 refs.

  18. Curdlan-conjugated PLGA nanoparticles possess macrophage stimulant activity and drug delivery capabilities

    CSIR Research Space (South Africa)

    Tukulula, M

    2015-02-01

    Full Text Available There is significant interest in the application of nanoparticles to deliver immunostimulatory signals to cells. We hypothesized that curdlan (immune stimulating polymer) could be conjugated to PLGA and nanoparticles from this copolymer would...

  19. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1994-04-20

    New, high-strength, hollow, glass microspheres filled with pressurized hydrogen exhibit storage densities which make them attractive for bulk hydrogen storage and transport. The hoop stress at failure of our engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which fail at wall stresses of 50,000 psi. For this project, microsphere material and structure will be optimized for storage capacity and charge/discharge kinetics to improve their commercial practicality. Microsphere production scale up will be performed, directed towards large-scale commercial use. Our analysis relating glass microspheres for hydrogen transport with infrastructure and economics` indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as hydride beds, cryocarbons and pressurized tube transports. For microspheres made from advanced materials and processes, analysis will also be performed to identify the appropriate applications of the microspheres considering property variables, and different hydrogen infrastructure, end use, production and market scenarios. This report presents some of the recent modelling results for large beds of glass microspheres in hydrogen storage applications. It includes plans for experiments to identify the properties relevant to large-bed hydrogen transport and storage applications, of the best, currently producible, glass microspheres. This work began in March, 1994. Project successes will be manifest in the matching of cur-rent glass microspheres with a useful application in hydrogen bulk transport and storage, and in developing microsphere materials and processes that increase the storage density and reduce the storage energy requirement.

  20. In vitro evaluation of biodegradable microspheres with surface-bound ligands.

    Science.gov (United States)

    Keegan, Mark E; Royce, Sara M; Fahmy, Tarek; Saltzman, W Mark

    2006-02-21

    Protein ligands were conjugated to the surface of biodegradable microspheres. These microsphere-ligand conjugates were then used in two in vitro model systems to evaluate the effect of conjugated ligands on microsphere behavior. Microsphere retention in agarose columns was increased by ligands on the microsphere surface specific for receptors on the agarose matrix. In another experiment, conjugating the lectin Ulex europaeus agglutinin 1 to the microsphere surface increased microsphere adhesion to Caco-2 monolayers compared to control microspheres. This increase in microsphere adhesion was negated by co-administration of l-fucose, indicating that the increase in adhesion is due to specific interaction of the ligand with carbohydrate receptors on the cell surface. These results demonstrate that the ligands conjugated to the microspheres maintain their receptor binding activity and are present on the microsphere surface at a density sufficient to target the microspheres to both monolayers and three-dimensional matrices bearing complementary receptors.

  1. Efficient chemotherapy of rat glioblastoma using doxorubicin-loaded PLGA nanoparticles with different stabilizers.

    Directory of Open Access Journals (Sweden)

    Stefanie Wohlfart

    Full Text Available BACKGROUND: Chemotherapy of glioblastoma is largely ineffective as the blood-brain barrier (BBB prevents entry of most anticancer agents into the brain. For an efficient treatment of glioblastomas it is necessary to deliver anti-cancer drugs across the intact BBB. Poly(lactic-co-glycolic acid (PLGA nanoparticles coated with poloxamer 188 hold great promise as drug carriers for brain delivery after their intravenous injection. In the present study the anti-tumour efficacy of the surfactant-coated doxorubicin-loaded PLGA nanoparticles against rat glioblastoma 101/8 was investigated using histological and immunohistochemical methods. METHODOLOGY: The particles were prepared by a high-pressure solvent evaporation technique using 1% polyvinylalcohol (PLGA/PVA or human serum albumin (PLGA/HSA as stabilizers. Additionally, lecithin-containing PLGA/HSA particles (Dox-Lecithin-PLGA/HSA were prepared. For evaluation of the antitumour efficacy the glioblastoma-bearing rats were treated intravenously with the doxorubicin-loaded nanoparticles coated with poloxamer 188 using the following treatment regimen: 3 × 2.5 mg/kg on day 2, 5 and 8 after tumour implantation; doxorubicin and poloxamer 188 solutions were used as controls. On day 18, the rats were sacrificed and the antitumour effect was determined by measurement of tumour size, necrotic areas, proliferation index, and expression of GFAP and VEGF as well as Isolectin B4, a marker for the vessel density. CONCLUSION: The results reveal a considerable anti-tumour effect of the doxorubicin-loaded nanoparticles. The overall best results were observed for Dox-Lecithin-PLGA/HSA. These data demonstrate that the poloxamer 188-coated PLGA nanoparticles enable delivery of doxorubicin across the blood-brain barrier in the therapeutically effective concentrations.

  2. Comparison of relative renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured with 99m Tc-DMSA static scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Domingues, F.C.; Fujikawa, G.Y.; Decker, H.; Alonso, G.; Pereira, J.C.; Duarte, P.S. [Centro de Diagnostico Fleury, Sao Paulo, SP (Brazil). Secao de Medicina Nuclear; Sao Paulo Univ. (USP), SP (Brazil). Escola de Saude Publica. Dept. de Epidemiologia]. E-mail: paulo.duarte@fleury.com.br

    2006-07-15

    Objective: The aim of this study was to compare the renal function measured with either {sup 99m}Tc-DTPA or {sup 99m}Tc-EC dynamic scintigraphies with that measured using {sup 99m}Tc-DMSA static scintigraphy. Methods: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with {sup 99m}Tc-DTPA (55 studies) or with {sup 99m}Tc-EC (56 studies) were compared with the relative function measured using {sup 99m}Tc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of {sup 99m}Tc-DTPA and {sup 99m}Tc-EC studies that presented relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA, using chi square test were also compared. Results: the relative renal function measured with {sup 99m}Tc-EC is not statistically different from that measured with {sup 99m}Tc-DMSA (p = 0.97). The relative renal function measured with {sup 99m}Tc-DTPA was statistically different from that measured using {sup 99m}Tc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with {sup 99m}Tc-DMSA is higher for the {sup 99m}Tc-DTPA scintigraphy (p 0.04) than for {sup 99m}Tc-EC. Conclusion: the relative renal function measured with {sup 99m}Tc-EC dynamic scintigraphy is comparable with that measured with {sup 99m}Tc-DMSA static scintigraphy, while the relative renal function measured with {sup 99m}Tc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with {sup 99m}Tc-DMSA static scintigraphy. (author)

  3. Comparison of relative renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured with 99m Tc-DMSA static scintigraphy

    International Nuclear Information System (INIS)

    Domingues, F.C.; Fujikawa, G.Y.; Decker, H.; Alonso, G.; Pereira, J.C.; Duarte, P.S.; Sao Paulo Univ.

    2006-01-01

    Objective: The aim of this study was to compare the renal function measured with either 99m Tc-DTPA or 99m Tc-EC dynamic scintigraphies with that measured using 99m Tc-DMSA static scintigraphy. Methods: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with 99m Tc-DTPA (55 studies) or with 99m Tc-EC (56 studies) were compared with the relative function measured using 99m Tc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of 99m Tc-DTPA and 99m Tc-EC studies that presented relative renal function different by more than 5% from that measured with 99m Tc-DMSA, using chi square test were also compared. Results: the relative renal function measured with 99m Tc-EC is not statistically different from that measured with 99m Tc-DMSA (p = 0.97). The relative renal function measured with 99m Tc-DTPA was statistically different from that measured using 99m Tc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with 99m Tc-DMSA is higher for the 99m Tc-DTPA scintigraphy (p 0.04) than for 99m Tc-EC. Conclusion: the relative renal function measured with 99m Tc-EC dynamic scintigraphy is comparable with that measured with 99m Tc-DMSA static scintigraphy, while the relative renal function measured with 99m Tc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with 99m Tc-DMSA static scintigraphy. (author)

  4. The influence of spray-drying parameters on phase behavior, drug distribution, and in vitro release of injectable microspheres for sustained release.

    Science.gov (United States)

    Meeus, Joke; Lenaerts, Maité; Scurr, David J; Amssoms, Katie; Davies, Martyn C; Roberts, Clive J; Van Den Mooter, Guy

    2015-04-01

    For ternary solid dispersions, it is indispensable to characterize their structure, phase behavior, and the spatial distribution of the dispersed drug as this might influence the release profile and/or stability of these formulations. This study shows how formulation (feed concentration) and process (feed rate, inlet air temperature, and atomizing air pressure) parameters can influence the characteristics of ternary spray-dried solid dispersions. The microspheres considered here consist of a poly(lactic-co-glycolic acid) (PLGA) surface layer and an underlying polyvinylpyrrolidone (PVP) phase. A poorly soluble active pharmaceutical ingredient (API) was molecularly dispersed in this matrix. Differences were observed in component miscibility, phase heterogeneity, particle size, morphology, as well as API surface coverage for selected spray-drying parameters. Observed differences are likely because of changes in the droplet generation, evaporation, and thus particle formation processes. However, varying particle characteristics did not influence the drug release of the formulations studied, indicating the robustness of this approach to produce particles of consistent drug release characteristics. This is likely because of the fact that the release is dominated by diffusion from the PVP layer through pores in the PLGA surface layer and that observed differences in the latter have no influence on the release. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Nanobody conjugated PLGA nanoparticles for active targeting of African Trypanosomiasis.

    Science.gov (United States)

    Arias, José L; Unciti-Broceta, Juan D; Maceira, José; Del Castillo, Teresa; Hernández-Quero, José; Magez, Stefan; Soriano, Miguel; García-Salcedo, José A

    2015-01-10

    Targeted delivery of therapeutics is an alternative approach for the selective treatment of infectious diseases. The surface of African trypanosomes, the causative agents of African trypanosomiasis, is covered by a surface coat consisting of a single variant surface glycoprotein, termed VSG. This coat is recycled by endocytosis at a very high speed, making the trypanosome surface an excellent target for the delivery of trypanocidal drugs. Here, we report the design of a drug nanocarrier based on poly ethylen glycol (PEG) covalently attached (PEGylated) to poly(D,L-lactide-co-glycolide acid) (PLGA) to generate PEGylated PLGA nanoparticles. This nanocarrier was coupled to a single domain heavy chain antibody fragment (nanobody) that specifically recognizes the surface of the protozoan pathogen Trypanosoma brucei. Nanoparticles were loaded with pentamidine, the first-line drug for T. b. gambiense acute infection. An in vitro effectiveness assay showed a 7-fold decrease in the half-inhibitory concentration (IC50) of the formulation relative to free drug. Furthermore, in vivo therapy using a murine model of African trypanosomiasis demonstrated that the formulation cured all infected mice at a 10-fold lower dose than the minimal full curative dose of free pentamidine and 60% of mice at a 100-fold lower dose. This nanocarrier has been designed with components approved for use in humans and loaded with a drug that is currently in use to treat the disease. Moreover, this flexible nanobody-based system can be adapted to load any compound, opening a range of new potential therapies with application to other diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Design and Optimization of PLGA-Based Diclofenac Loaded Nanoparticles

    Science.gov (United States)

    Cooper, Dustin L.; Harirforoosh, Sam

    2014-01-01

    Drug based nanoparticle (NP) formulations have gained considerable attention over the past decade for their use in various drug formulations. NPs have been shown to increase bioavailability, decrease side effects of highly toxic drugs, and prolong drug release. Nonsteroidal anti-inflammatory drugs such as diclofenac block cyclooxygenase expression and reduce prostaglandin synthesis, which can lead to several side effects such as gastrointestinal bleeding and renal insufficiency. The aim of this study was to formulate and characterize diclofenac entrapped poly(lactide-co-glycolide) (PLGA) based nanoparticles. Nanoparticles were formulated using an emulsion-diffusion-evaporation technique with varying concentrations of poly vinyl alcohol (PVA) (0.1, 0.25, 0.5, or 1%) or didodecyldimethylammonium bromide (DMAB) (0.1, 0.25, 0.5, 0.75, or 1%) stabilizers centrifuged at 8,800 rpm or 12,000 rpm. The resultant nanoparticles were evaluated based on particle size, zeta potential, and entrapment efficacy. DMAB formulated NPs showed the lowest particle size (108±2.1 nm) and highest zeta potential (−27.71±0.6 mV) at 0.1 and 0.25% respectively, after centrifugation at 12,000 rpm. Results of the PVA based NP formulation showed the smallest particle size (92.4±7.6 nm) and highest zeta potential (−11.14±0.5 mV) at 0.25% and 1% w/v, respectively, after centrifugation at 12,000 rpm. Drug entrapment reached 77.3±3.5% and 80.2±1.2% efficiency with DMAB and PVA formulations, respectively. The results of our study indicate the use of DMAB for increased nanoparticle stability during formulation. Our study supports the effective utilization of PLGA based nanoparticle formulation for diclofenac. PMID:24489896

  7. Design and optimization of PLGA-based diclofenac loaded nanoparticles.

    Directory of Open Access Journals (Sweden)

    Dustin L Cooper

    Full Text Available Drug based nanoparticle (NP formulations have gained considerable attention over the past decade for their use in various drug formulations. NPs have been shown to increase bioavailability, decrease side effects of highly toxic drugs, and prolong drug release. Nonsteroidal anti-inflammatory drugs such as diclofenac block cyclooxygenase expression and reduce prostaglandin synthesis, which can lead to several side effects such as gastrointestinal bleeding and renal insufficiency. The aim of this study was to formulate and characterize diclofenac entrapped poly(lactide-co-glycolide (PLGA based nanoparticles. Nanoparticles were formulated using an emulsion-diffusion-evaporation technique with varying concentrations of poly vinyl alcohol (PVA (0.1, 0.25, 0.5, or 1% or didodecyldimethylammonium bromide (DMAB (0.1, 0.25, 0.5, 0.75, or 1% stabilizers centrifuged at 8,800 rpm or 12,000 rpm. The resultant nanoparticles were evaluated based on particle size, zeta potential, and entrapment efficacy. DMAB formulated NPs showed the lowest particle size (108 ± 2.1 nm and highest zeta potential (-27.71 ± 0.6 mV at 0.1 and 0.25% respectively, after centrifugation at 12,000 rpm. Results of the PVA based NP formulation showed the smallest particle size (92.4 ± 7.6 nm and highest zeta potential (-11.14 ± 0.5 mV at 0.25% and 1% w/v, respectively, after centrifugation at 12,000 rpm. Drug entrapment reached 77.3 ± 3.5% and 80.2 ± 1.2% efficiency with DMAB and PVA formulations, respectively. The results of our study indicate the use of DMAB for increased nanoparticle stability during formulation. Our study supports the effective utilization of PLGA based nanoparticle formulation for diclofenac.

  8. Mannan-Modified PLGA Nanoparticles for Targeted Gene Delivery

    Directory of Open Access Journals (Sweden)

    Fansheng Kong

    2012-01-01

    Full Text Available The studies of targeted gene delivery nanocarriers have gained increasing attention during the past decades. In this study, mannan modified DNA loaded bioadhesive PLGA nanoparticles (MAN-DNA-NPs were investigated for targeted gene delivery to the Kupffer cells (KCs. Bioadhesive PLGA nanoparticles were prepared and subsequently bound with pEGFP. Following the coupling of the mannan-based PE-grafted ligands (MAN-PE with the DNA-NPs, the MAN-DNA-NPs were delivered intravenously to rats. The transfection efficiency was determined from the isolated KCs and flow cytometry was applied for the quantitation of gene expression after 48 h post transfection. The size of the MAN-DNA-NPs was found to be around 190 nm and the Zeta potential was determined to be −15.46mV. The pEGFP binding capacity of MAN-DNA-NPs was (88.9±5.8% and the in vitro release profiles of the MAN-DNA-NPs follow the Higuchi model. When compared with non-modified DNA-NPs and Lipofectamine 2000-DNA, MAN-DNA-NPs produced the highest gene expressions, especially in vivo. The in vivo data from flow cytometry analysis showed that MAN-DNA-NPs displayed a remarkably higher transfection efficiency (39% than non-modified DNA-NPs (25% and Lipofectamine 2000-DNA (23% in KCs. The results illustrate that MAN-DNA-NPs have the ability to target liver KCs and could function as promising active targeting drug delivery vectors.

  9. In vivo and in vitro study of the 99mTc-DMSA radiopharmaceutical connection to blood elements

    International Nuclear Information System (INIS)

    Freitas, Rosimeire de S.; Gomes, Maria L.; Mattos, Deise M.M.; Moreno, Silvana R.F.; Dire, Glaucio F.; Lima, Elaine A.; Lima-Filho, Guilherme L.; Aleixo, Luiz Claudio; Bernardo-Filho, Mario; Instituto Nacional do Cancer, Rio de Janeiro

    2002-01-01

    Radiopharmaceuticals are widely used in nuclear medicine. The comprehension of their uptake mechanism in target organs, as well as their clearance may depend on the elucidation of their biochemical characteristics, for instance, their binding to blood elements. The reported precipitating studies of blood with radiopharmaceuticals have shown that the results can not be easily compared. Then, we decide evaluate of the binding proteins on the blood elements using trichloroacetic acid (TCA) to determine the radioactivity of the dimercaptosuccinic acid with technetium-99m (99mTc-DMSA) present in precipitating plasma (P) and blood cells (BC). Depending on the TCA concentration we have determined different values in the insoluble fractions of the plasma when the in vivo and in vitro evaluations were carried out. (author)

  10. pH-Responsive PLGA Nanoparticle for Controlled Payload Delivery of Diclofenac Sodium

    Directory of Open Access Journals (Sweden)

    Shalil Khanal

    2016-08-01

    Full Text Available Poly(lactic-co-glycolic acid (PLGA based nanoparticles have gained increasing attention in delivery applications due to their capability for controlled drug release characteristics, biocompatibility, and tunable mechanical, as well as degradation, properties. However, thorough study is always required while evaluating potential toxicity of the particles from dose dumping, inconsistent release and drug-polymer interactions. In this research, we developed PLGA nanoparticles modified by chitosan (CS, a cationic and pH responsive polysaccharide that bears repetitive amine groups in its backbone. We used a model drug, diclofenac sodium (DS, a nonsteroidal anti-inflammatory drug (NSAID, to study the drug loading and release characteristics. PLGA nanoparticles were synthesized by double-emulsion solvent evaporation technique. The nanoparticles were evaluated based on their particle size, surface charge, entrapment efficacy, and effect of pH in drug release profile. About 390–420 nm of average diameters and uniform morphology of the particles were confirmed by scanning electron microscope (SEM imaging and dynamic light scattering (DLS measurement. Chitosan coating over PLGA surface was confirmed by FTIR and DLS. Drug entrapment efficacy was up to 52%. Chitosan coated PLGA showed a pH responsive drug release in in vitro. The release was about 45% more at pH 5.5 than at pH 7.4. The results of our study indicated the development of chitosan coating over PLGA nanoparticle for pH dependent controlled release DS drug for therapeutic applications.

  11. Morphological Effects of HA on the Cell Compatibility of Electrospun HA/PLGA Composite Nanofiber Scaffolds

    Directory of Open Access Journals (Sweden)

    Adnan Haider

    2014-01-01

    Full Text Available Tissue engineering is faced with an uphill challenge to design a platform with appropriate topography and suitable surface chemistry, which could encourage desired cellular activities and guide bone tissue regeneration. To develop such scaffolds, composite nanofiber scaffolds of nHA and sHA with PLGA were fabricated using electrospinning technique. nHA was synthesized using precipitation method, whereas sHA was purchased. The nHA and sHA were suspended in PLGA solution separately and electrospun at optimized electrospinning parameters. The composite nanofiber scaffolds were characterized by FE-SEM, EDX analysis, TEM, XRD analysis, FTIR, and X-ray photoelectron. The potential of the HA/PLGA composite nanofiber as bone scaffolds in terms of their bioactivity and biocompatibility was assessed by culturing the osteoblastic cells onto the composite nanofiber scaffolds. The results from in vitro studies revealed that the nHA/PLGA composite nanofiber scaffolds showed higher cellular adhesion, proliferation, and enhanced osteogenesis performance, along with increased Ca+2 ions release compared to the sHA/PLGA composite nanofiber scaffolds and pristine PLGA nanofiber scaffold. The results show that the structural dependent property of HA might affect its potential as bone scaffold and implantable materials in regenerative medicine and clinical tissue engineering.

  12. Cuban typical doses for 99mTc-DMSA renal gammagraphy studies: a methodology for the establishment of reference levels

    International Nuclear Information System (INIS)

    Diaz Barreto, M.; Varela Corona, C.; Lopez Bejerano, G.M.; Perea Diaz, M.; Paz Viera, J.E.

    2008-01-01

    Since a handful of years ago, international rules on Radiological Protection include the principle of optimization of given dose to patients, if this procedure doesn't lessen diagnosis quality, and the establishment of reference levels of activity. For these reasons, the Radiological Protection staff of Cuban Institute of Nephrology's Nuclear Medicine Service, where morpho functional renal studies are carried out, 70% on infants and young children, started a research on that way. Thus, because their biggest incidence, 99m Tc -DMSA renal gammagraphy studies were chosen, using a General Electric 400 AT Planar Gamma Camera. Studied sample was randomly selected, including adults (12 peoples) and children (23); divided into 4 groups, lessen given dose step by step. Other items were kept in mind in the research, such age, weight, time delayed between administrations and image getting, getting time of each view and total time of the study, as well as radiopharmaceuticals quality and Gamma Camera performance. Image quality was evaluated for each case, using both, objective and subjective criteria. Objective evaluation was done by using contrast/noise ratios and variance of the random noise. They were used to develop clustering and discriminant analysis over the independent variables to detect groups with differentiated image quality from the physical and mathematical point of view. Subjective evaluation was performed using the criteria of two expert observers who had no information about the activity levels used. They evaluated image quality separately, giving a good, regular or bad evaluation for each image. As a conclusion, we found that it is possible to reduce the given activities in 50% and thus, indirectly, to reduce doses for workers and for the public. Additionally, we propose a methodology for the establishment of reference levels for 99m Tc -DMSA renal gammagraphy studies in Cuba, both, for adults and paediatric patients. (author)

  13. [Calculation of the partial function of the kidney with DMSA in pediatrics: is the evaluation of the geometric mean necessary?].

    Science.gov (United States)

    Porn, U; Rossmüller, B; Alalp, S; Fischer, S; Dresel, S; Hahn, K

    2001-08-01

    For assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimercaptosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. Of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 +/- 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256, 300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Ctsdors x Ctsventr)]. The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p or = 5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PFdors due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference > 5% did not show any renal abnormality. The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differential renal function in orthotopic kidneys, so that in these cases the anterior view is not necessary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in cases with an obvious anatomical abnormality.

  14. A study on 99Tcm-citrate and 99Tcm (V)-DMSA imaging in the diagnosis of acute purulent osteoarthritis

    International Nuclear Information System (INIS)

    Wu Zhaozhong; Lin Wei; Wu Hengfu; Wu Changwei; Yuan Gewen; Fan Ziwen; Wu Boyi

    2003-01-01

    Objective: To assess the clinical diagnostic value of 99 Tc m -citrate and 99 Tc m (1/2ae)-dimercaptosuccinic acid (DMSA) imaging in the acute purulent osteoarthritis. Methods: Seventeen patients with confirmed acute purulent osteoarthritis and nineteen patients with non-purulent osteoarthritis were studied. In all patients, 99 Tc m -methylene diphosphonic acid (MDP), 99 Tc m -citrate and 99 Tc m (1/2ae)-DMSA imaging were sequentially performed and the images were analyzed semiquantitatively. Results: In the acute purulent osteoarthritis group, there were positive bonetactic accumulations at certain areas on the three kinds of imaging. In the non-purulent osteoarthritis group, 99 Tc m -MDP and 99 Tc m (1/2ae)-DMSA imaging showed clear bonetactic accumulation, but 99 Tc m -citrate imaging showed only light bonetactic accumulation in addition to the accumulations in soft tissue at certain areas. Lesion to nonlesion ratio (L/N=2.300±0.094) of acute purulent osteoarthritis was greater than that in non-purulent osteoarthritis group (1.298±0.054, P 99 Tc m -citrate imaging, and there was no significant difference between two groups on 99 Tc m (1/2ae)-DMSA imaging (L/N ratio of acute purulent osteoarthritis group was 3.495±0.180, and L/N ratio of non-purulent osteoarthritis group was 3.091±0.091, P>0.05). Conclusions: To diagnose the bone inflammation, 99 Tc m -citrate imaging coalesced with 99 Tc m -MDP or 99 Tc m (1/2ae)-DMSA imaging can help to evaluate the pathologic and physiologic progresses in bone inflammatory areas, at the same time , the information by 99 Tc m -citrate imaging is telling the actual inflammation areas, and that by 99 Tc m (1/2ae)-DMSA and 99 Tc m -MDP imaging is about the response to the increase of bone metabolism

  15. Hydroxypropyltrimethyl Ammonium Chloride Chitosan Functionalized-PLGA Electrospun Fibrous Membranes as Antibacterial Wound Dressing: In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Shengbing Yang

    2017-12-01

    Full Text Available A novel poly(lactic-co-glycolic acid (PLGA-hydroxypropyltrimethyl ammonium chloride chitosan (HACC composite nanofiber wound dressing was prepared through electrospinning and the entrapment-graft technique as an antibacterial dressing for cutaneous wound healing. HACC with 30% degrees of substitution (DS was immobilized onto the surface of PLGA membranes via the reaction between carboxyl groups in PLGA after alkali treatment and the reactive groups (–NH2 in HACC molecules. The naked PLGA and chitosan graft PLGA (PLGA-CS membranes served as controls. The surface immobilization was characterized by scanning electron microscopy (SEM, atomic force microscopy (AFM, Fourier transform infrared (FTIR, thermogravimetric analysis (TGA and energy dispersive X-ray spectrometry (EDX. The morphology studies showed that the membranes remain uniform after the immobilization process. The effects of the surface modification by HACC and CS on the biological properties of the membranes were also investigated. Compared with PLGA and PLGA-CS, PLGA-HACC exhibited more effective antibacterial activity towards both Gram-positive (S. aureus and Gram-negative (P. aeruginosa bacteria. The newly developed fibrous membranes were evaluated in vitro for their cytotoxicity using human dermal fibroblasts (HDFs and human keratinocytes (HaCaTs and in vivo using a wound healing mice model. It was revealed that PLGA-HACC fibrous membranes exhibited favorable cytocompatibility and significantly stimulated adhesion, spreading and proliferation of HDFs and HaCaTs. PLGA-HACC exhibited excellent wound healing efficacy, which was confirmed using a full thickness excision wound model in S. aureus-infected mice. The experimental results in this work suggest that PLGA-HACC is a strong candidate for use as a therapeutic biomaterial in the treatment of infected wounds.

  16. Optically Levitated Microspheres as a Probe for New Interactions

    Science.gov (United States)

    Rider, Alexander; Moore, David; Blakemore, Charles; Lu, Marie; Gratta, Giorgio

    2016-03-01

    We are developing novel techniques to probe new interactions at micron distances using optically levitated dielectric microspheres. Levitated microspheres are an ideal probe for short-range interactions because they are suspended using the radiation pressure at the focus of a laser beam, which means that the microspheres can be precisely manipulated and isolated from the surrounding environment at high vacuum. We have performed a search for unknown charged particles bound within the bulk of the microspheres. Currently, we are searching for the presence of a Chameleon field postulated to explain the presence of dark energy in the universe. In the future we plan to use optically levitated microspheres to search for micron length-scale gravity like interactions that could couple between a microsphere and another mass. We will present resent results from these experiments and plans for future searches for new interactions.

  17. Hydrogen transport and storage in engineered glass microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Rambach, G.D.

    1995-02-28

    New, high strength glass microspheres filled with pressurized hydrogen exhibit densities which make them attractive for bulk hydrogen storage and transport. The membrane tensile stress at failure for engineered glass microspheres is about 150,000 psi, permitting a three-fold increase in pressure limit and storage capacity above commercial microspheres, which have been studied a decade ago and have been shown to fail at membrane stresses of 50,000 psi. This analysis relating glass microspheres for hydrogen transport with infrastructure and economics, indicate that pressurized microspheres can be economically competitive with other forms of bulk rail and truck transport such as pressurized tube transports and liquid hydrogen trailers. This paper will describe the matching of current glass microspheres with the useful application in commercial hydrogen bulk transport and storage.

  18. Beat frequency ultrasonic microsphere contrast agent detection system

    Science.gov (United States)

    Pretlow, III, Robert A. (Inventor); Yost, William T. (Inventor); Cantrell, Jr., John H. (Inventor)

    1997-01-01

    A system for and method of detecting and measuring concentrations of an ultrasonically-reflective microsphere contrast agent involving detecting non-linear sum and difference beat frequencies produced by the microspheres when two impinging signals with non-identical frequencies are combined by mixing. These beat frequencies can be used for a variety of applications such as detecting the presence of and measuring the flow rates of biological fluids and industrial liquids, including determining the concentration level of microspheres in the myocardium.

  19. Microsphere formation in droplets using antisolvent vapour precipitation technique

    OpenAIRE

    Chew, Sean Jun Liang

    2017-01-01

    In previous studies, the antisolvent vapour precipitation method has been proven to produce uniformly sized lactose microspheres (1.0 µm) from a single droplet (1.2 mm diameter) at atmospheric pressure. These types of particles have potential applications in the pharmaceutical industry, especially due to their high dissolution rate. This project looked into the possibility of using antisolvent vapour precipitation to produce microspheres from finely atomised droplets. Microspheres in the sub-...

  20. Efficient production of retroviruses using PLGA/bPEI-DNA nanoparticles and application for reprogramming somatic cells.

    Directory of Open Access Journals (Sweden)

    Eun Jin Seo

    Full Text Available Reprogramming of somatic cells to pluripotent cells requires the introduction of factors driving fate switches. Viral delivery has been the most efficient method for generation of induced pluripotent stem cells. Transfection, which precedes virus production, is a commonly-used process for delivery of nucleic acids into cells. The aim of this study is to evaluate the efficiency of PLGA/ bPEI nanoparticles in transfection and virus production. Using a modified method of producing PLGA nanoparticles, PLGA/bPEI-DNA nanoparticles were examined for transfection efficiency and virus production yield in comparison with PLGA-DNA, bPEI-DNA nanoparticles or liposome-DNA complexes. After testing various ratios of PLGA, bPEI, and DNA, the ratio of 6:3:1 (PLGA:bPEI:DNA, w/w/w was determined to be optimal, with acceptable cellular toxicity. PLGA/bPEI-DNA (6:3:1 nanoparticles showed superior transfection efficiency, especially in multiple gene transfection, and viral yield when compared with liposome-DNA complexes. The culture supernatants of HEK293FT cells transfected with PLGA/bPEI-DNA of viral constructs containing reprogramming factors (Oct4, Sox2, Klf4, or c-Myc successfully and more efficiently generated induced pluripotent stem cell colonies from mouse embryonic fibroblasts. These results strongly suggest that PLGA/bPEI-DNA nanoparticles can provide significant advantages in studying the effect of multiple factor delivery such as in reprogramming or direct conversion of cell fate.

  1. Efficacy of the biomaterials 3 wt%-nanostrontium-hydroxyapatite-enhanced calcium phosphate cement (nanoSr-CPC) and nanoSr-CPC-incorporated simvastatin-loaded poly(lactic-co-glycolic-acid) microspheres in osteogenesis improvement: An explorative multi-phase experimental in vitro/vivo study

    International Nuclear Information System (INIS)

    Masaeli, Reza; Jafarzadeh Kashi, Tahereh Sadat; Dinarvand, Rassoul; Rakhshan, Vahid; Shahoon, Hossein; Hooshmand, Behzad; Mashhadi Abbas, Fatemeh; Raz, Majid; Rajabnejad, Alireza; Eslami, Hossein; Khoshroo, Kimia

    2016-01-01

    Aims: The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3 wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA + nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Methods and results pertaining to Sr-HA/CPC: Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P < 0.05). Histomorphometry showed greater bone formation after 4 weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n = 30, ANOVA P < 0.05). Methods and results pertaining to SIM-loaded PLGA microspheres + nanostrontium-CPC composite: After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8 weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n = 50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96 ± 1.01), bone materials (32.28 ± 4.03), nanostrontium-CPC (24.84 ± 2.6), nanostrontium-CPC-simvastatin (40

  2. Efficacy of the biomaterials 3 wt%-nanostrontium-hydroxyapatite-enhanced calcium phosphate cement (nanoSr-CPC) and nanoSr-CPC-incorporated simvastatin-loaded poly(lactic-co-glycolic-acid) microspheres in osteogenesis improvement: An explorative multi-phase experimental in vitro/vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Masaeli, Reza [Dental Biomaterials Department, School of Dentistry, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Jafarzadeh Kashi, Tahereh Sadat, E-mail: jafarzat@sina.tums.ac.ir [Dental Biomaterials Department, School of Dentistry, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Iranian Tissue Bank and Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Dinarvand, Rassoul [Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Rakhshan, Vahid [Iranian Tissue Bank and Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahoon, Hossein [Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahed University, Tehran (Iran, Islamic Republic of); Hooshmand, Behzad [Department of Periodontology, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mashhadi Abbas, Fatemeh [Department of Oral and Maxillofacial Pathology, School of Dentistry, Shahid Beheshti Medical Science University, Tehran (Iran, Islamic Republic of); Raz, Majid; Rajabnejad, Alireza; Eslami, Hossein [Biomaterials Group, Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Khoshroo, Kimia [Dental Biomaterials Department, School of Dentistry, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Developmental Sciences, School of Dentistry, Marquette University, Milwaukee, WI (United States); and others

    2016-12-01

    Aims: The purpose of this multi-phase explorative in vivo animal/surgical and in vitro multi-test experimental study was to (1) create a 3 wt%-nanostrontium hydroxyapatite-enhanced calcium phosphate cement (Sr-HA/CPC) for increasing bone formation and (2) creating a simvastatin-loaded poly(lactic-co-glycolic acid) (SIM-loaded PLGA) microspheres plus CPC composite (SIM-loaded PLGA + nanostrontium-CPC). The third goal was the extensive assessment of multiple in vitro and in vivo characteristics of the above experimental explorative products in vitro and in vivo (animal and surgical studies). Methods and results pertaining to Sr-HA/CPC: Physical and chemical properties of the prepared Sr-HA/CPC were evaluated. MTT assay and alkaline phosphatase activities, and radiological and histological examinations of Sr-HA/CPC, CPC and negative control were compared. X-ray diffraction (XRD) indicated that crystallinity of the prepared cement increased by increasing the powder-to-liquid ratio. Incorporation of Sr-HA into CPC increased MTT assay (biocompatibility) and ALP activity (P < 0.05). Histomorphometry showed greater bone formation after 4 weeks, after implantation of Sr-HA/CPC in 10 rats compared to implantations of CPC or empty defects in the same rats (n = 30, ANOVA P < 0.05). Methods and results pertaining to SIM-loaded PLGA microspheres + nanostrontium-CPC composite: After SEM assessment, the produced composite of microspheres and enhanced CPC were implanted for 8 weeks in 10 rabbits, along with positive and negative controls, enhanced CPC, and enhanced CPC plus SIM (n = 50). In the control group, only a small amount of bone had been regenerated (localized at the boundary of the defect); whereas, other groups showed new bone formation within and around the materials. A significant difference was found in the osteogenesis induced by the groups sham control (16.96 ± 1.01), bone materials (32.28 ± 4.03), nanostrontium-CPC (24.84 ± 2.6), nanostrontium-CPC-simvastatin (40

  3. Preparation of polystyrene microsphere with emulsion microencapsulation method

    International Nuclear Information System (INIS)

    Li Bo Zhang Lin; Zhang Zhganwen; You Dan; Wei Yun; Wang Chaoyang; Lin Bo; Shi Tao; Chu Qiaomei

    2003-01-01

    The preparation of hollow polystyrene microspheres that are used as inner shell of multi-shell plastic microspheres in the ICF experiments is focused on. The effects of surfactants, water-soluble polymer and electrolyte on the properties of resultant microspheres are studied. Based on these experiments, a fabricating procedure was established with which hollow microspheres were prepared with diameter about 150-3000 μm, wall thickness 0.8-15 μm and toughness Ra less than 4 nm. (authors)

  4. Intestinal absorption of PLAGA microspheres in the rat.

    Science.gov (United States)

    Damgé, C; Aprahamian, M; Marchais, H; Benoit, J P; Pinget, M

    1996-12-01

    Rhodamine B-labelled poly (DL-lactide-co-glycolide) (PLAGA) microspheres of 2 different sizes, 1-5 microns and 5-10 microns, were administered as a single dose (1.44 x 10(9) and 1.83 x 10(8) particles, respectively) into the ileal lumen of adult rats. The content of rhodamine in the mesenteric vein and ileal lumen was analysed periodically from 10 min to 48 h as well as the distribution of microspheres in the intestinal mucosa and various other tissues. The concentration of rhodamine decreased progressively in the intestinal lumen and was negligible after 24 h. The number of microspheres in the mesenteric vein increased rapidly and reached a maximum after 4 h whatever the size of the particles. It then decreased progressively, but more rapidly with microspheres > 5 microns than with microspheres PLAGA microspheres mainly crossed the intestinal mucosa at the site of Peyer's patches where microspheres of 5 microns were retained in the ileal lumen. A few small microspheres were occasionally observed in the epithelial cells. Only the smallest particles were recovered in the liver, lymph nodes and spleen while basement membranes were always labelled. It is concluded that PLAGA microspheres could be useful for the oral delivery of antigens if their size is between 1 and 5 microns.

  5. Preparation of porous zirconia microspheres by internal gelation method

    International Nuclear Information System (INIS)

    Pathak, Sachin S.; Pius, I.C.; Bhanushali, R.D.; Rao, T.V. Vittal; Mukerjee, S.K.

    2008-01-01

    A modified internal gelation process for the preparation of porous zirconia microspheres has been developed. The conventional method has been modified by adding a surfactant in the feed broth. The effects of variation of surfactant concentration, washing techniques and temperature of calcination on the pore volume and the surface area of the microspheres have been studied. The conditions were optimized to obtain porous stable microspheres suitable for various applications. The microspheres were characterized by surface area analysis, pore volume analysis, thermogravimetric analysis and X-ray diffraction. The ion exchange behavior was studied using pH titration

  6. Photoluminescence and lasing in whispering gallery mode glass microspherical resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ristić, D. [Ruđer Bošković Institute, Division of Materials Physics, Laboratory for Molecular Physics, Bijenička c. 54, Zagreb (Croatia); Center of Excellence for Advanced Materials and Sensing Devices, Research unit New Functional Materials, Bijenička c. 54, Zagreb (Croatia); Berneschi, S.; Camerini, M. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Farnesi, D.; Pelli, S. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Trono, C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Chiappini, A.; Chiasera, A.; Ferrari, M. [CSMFO Group, Istituto di Fotonica e Nanotecnologie, IFN-CNR, Via alla Cascata 56/C, 38050 Povo-Trento (Italy); Lukowiak, A. [Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, Wroclaw 50-950 (Poland); Dumeige, Y.; Féron, P. [Laboratoire d' Optronique, (CNRS-UMR 6082-Foton), ENSSAT, 6 rue de Kérampont, 22300 Lannion (France); Righini, G.C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Soria, S., E-mail: s.soria@ifac.cnr.it [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Conti, G. Nunzi [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy)

    2016-02-15

    We report experimental results regarding the development of Er{sup 3+}-doped glass microspherical cavities for the fabrication of compact sources at 1.55 μm. We investigate several different approaches in order to fabricate the microspheres including direct melting of Er{sup 3+}-doped glass powders, synthesis of Er{sup 3+}-doped monolithic microspheres by drawing Er{sup 3+}-doped glass, and coating of silica microspheres with an Er{sup 3+}-doped sol–gel layer. Details of the different fabrication processes are presented together with the photoluminescence characterization in free space configuration of the microspheres and of the glass precursor. We have analyzed the photoluminescence spectra of the whispering gallery modes of the microspheres excited using evanescent coupling and we demonstrate tunable laser action in a wide range of wavelengths around 1.55 μm. As much as 90 μW of laser output power was measured in Er{sup 3+}-doped glass microspheres. - Highlights: • Different approaches in microsphere fabrication and various types of post-processing. • Trimming of photorefractive glass microsphere lasers with UV light. • Peak power record of 90 μW by pumping at 1480 nm.

  7. Microsphere based improved sunscreen formulation of ethylhexyl methoxycinnamate.

    Science.gov (United States)

    Gogna, Deepak; Jain, Sunil K; Yadav, Awesh K; Agrawal, G P

    2007-04-01

    Polymethylmethacrylate (PMMA) microspheres of ethylhexyl methoxycinnamate (EHM) were prepared by emulsion solvent evaporation method to improve its photostability and effectiveness as sunscreening agent. Process parameters like stirring speed and aqueous polyvinyl alcohol (PVA) concentration were analyzed in order to optimize the formulations. Shape and surface morphology of the microspheres were examined using scanning electron microscopy. Particle size of the microspheres was determined using laser diffraction particle size analyzer. The PMMA microspheres of EHM were incorporated in water-removable cream base. The in vitro drug release of EHM in pH 7.4 was performed using dialysis membrane. Thin layer chromatography was performed to determine photostability of EHM inside the microspheres. The formulations were evaluated for sun protection factor (SPF) and minimum erythema dose (MED) in albino rats. Cream base formulation containing microspheres prepared using EHM:PMMA in ratio of 1:3 (C(3)) showed slowest drug (EHM) release and those prepared with EHM: PMMA in ratio of 1:1 showed fastest release. The cream base formulations containing EHM loaded microspheres had shown better SPF (more than 16.0) as compared to formulation C(d) that contained 3% free EHM as sunscreen agent and showed SPF 4.66. These studies revealed that the incorporation of EHM loaded PMMA microspheres into cream base had greatly increased the efficacy of sunscreen formulation approximately four times. Further, photostability was also shown to be improved in PMMA microspheres.

  8. Low pressure gas filling of laser fusion microspheres

    International Nuclear Information System (INIS)

    Koo, J.C.; Dressler, J.L.; Hendricks, C.D.

    1979-01-01

    In our laser fusion microsphere production, large, thin gel-microspheres are formed before the chemicals are fused into glass. In this transient stage,, the gel-microspheres are found to be highly permeable to argon and many other inert gases. When the gel transforms to glass, the argon gas, for example, is trapped within to form argon filled, fusion target quality, glass microspheres. On the average, the partial pressure of the argon fills attained in this process is around 2 x 10 4 Pa at room temperature

  9. Histological Comparison of Kidney Tissue Following Radioembolization with Yttrium-90 Resin Microspheres and Embolization with Bland Microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Suresh de, E-mail: suresh.desilva@unsw.edu.au [Southern Radiology Group, Radiology Department Sutherland Hospital (Australia); Mackie, Simon [Western General Hospital, Department of Urology (United Kingdom); Aslan, Peter [St George Hospital, Department of Urology (Australia); Cade, David [Sirtex Technology Pty Ltd (Australia); Delprado, Warick [Douglass Hanly Moir Pathology (Australia)

    2016-12-15

    BackgroundIntra-arterial brachytherapy with yttrium-90 ({sup 90}Y) resin microspheres (radioembolization) is a procedure to selectively deliver high-dose radiation to tumors. The purpose of this research was to compare the radioembolic effect of {sup 90}Y-radioembolization versus the embolic effect of bland microspheres in the porcine kidney model.MethodsIn each of six pigs, ~25–33 % of the kidney volume was embolized with {sup 90}Y resin microspheres and an equivalent number of bland microspheres in the contralateral kidney. Kidney volume was estimated visually from contrast-enhanced fluoroscopy imaging. Morphologic and histologic analysis was performed 8–9 weeks after the procedure to assess the locations of the microspheres and extent of tissue necrosis from {sup 90}Y-radioembolization and bland embolization. A semi-quantified evaluation of the non-acute peri-particle and perivascular tissue reaction was conducted. All guidelines for the care and use of animals were followed.ResultsKidneys embolized with {sup 90}Y-radioembolization decreased in mass by 30–70 % versus the contralateral kidney embolized with bland microspheres. These kidneys showed significant necrosis/fibrosis, avascularization, and glomerular atrophy in the immediate vicinity of the {sup 90}Y resin microspheres. By contrast, glomerular changes were not observed, even with clusters of bland microspheres in afferent arterioles. Evidence of a foreign body reaction was recorded in some kidneys with bland microspheres, and subcapsular scarring/infarction only with the highest load (4.96 × 10{sup 6}) of bland microspheres.ConclusionThis study showed that radioembolization with {sup 90}Y resin microspheres produces localized necrosis/fibrosis and loss of kidney mass in a porcine kidney model. This result supports the study of {sup 90}Y resin microspheres for the localized treatment of kidney tumors.

  10. A novel route for synthesis and growth formation of metal oxides microspheres: Insights from V_2O_3 microspheres

    International Nuclear Information System (INIS)

    Zhang, Yifu; Huang, Chi; Meng, Changgong; Hu, Tao

    2016-01-01

    Highly polydisperse V_2O_3 solid microspheres with large specific surface area were successfully synthesized via a facile hydrothermal decomposition of VOC_2O_4 solution. The morphology and composition were characterized by scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). V_2O_3 microspheres display an obvious Mott phase transition at −128.5 °C (cooling curve) and −114.5 °C (heating curve). Some parameters including the reaction temperature, concentration of VOC_2O_4, reaction time, surfactant, H_2C_2O_4 and precursor were briefly discussed to reveal the formation of V_2O_3 microspheres. It was found that the precursor is crucial for the fabrication of microsphere. A self-assembly growth mechanism was suggested to explain the growth process of microspheres and the autogenic CO and CO_2 gas served as the soft templates. Furthermore, this route was developed to synthesize different metal oxides microspheres, and it was found that AlO(OH), Fe_3O_4, Fe_2O_3, Co_3O_4, Cr_2O_3, MoO_2 and WO_3 microspheres were obtained. All the results showed this process was successfully explored as a methodology to synthesize different metal oxides microspheres using the gas as the templates by this facile hydrothermal route. - Highlights: • Highly uniform V_2O_3 solid microspheres were synthesized. • V_2O_3 microspheres display an obvious Mott phase transition. • The autogenic CO and CO_2 gas served as the soft templates for designed synthesis. • AlO(OH), Fe_3O_4, Fe_2O_3, Co_3O_4, Cr_2O_3, MoO_2 and WO_3 microspheres were obtained. • A methodology to synthesize different metal oxides microspheres was developed.

  11. Histological Comparison of Kidney Tissue Following Radioembolization with Yttrium-90 Resin Microspheres and Embolization with Bland Microspheres

    International Nuclear Information System (INIS)

    Silva, Suresh de; Mackie, Simon; Aslan, Peter; Cade, David; Delprado, Warick

    2016-01-01

    BackgroundIntra-arterial brachytherapy with yttrium-90 ("9"0Y) resin microspheres (radioembolization) is a procedure to selectively deliver high-dose radiation to tumors. The purpose of this research was to compare the radioembolic effect of "9"0Y-radioembolization versus the embolic effect of bland microspheres in the porcine kidney model.MethodsIn each of six pigs, ~25–33 % of the kidney volume was embolized with "9"0Y resin microspheres and an equivalent number of bland microspheres in the contralateral kidney. Kidney volume was estimated visually from contrast-enhanced fluoroscopy imaging. Morphologic and histologic analysis was performed 8–9 weeks after the procedure to assess the locations of the microspheres and extent of tissue necrosis from "9"0Y-radioembolization and bland embolization. A semi-quantified evaluation of the non-acute peri-particle and perivascular tissue reaction was conducted. All guidelines for the care and use of animals were followed.ResultsKidneys embolized with "9"0Y-radioembolization decreased in mass by 30–70 % versus the contralateral kidney embolized with bland microspheres. These kidneys showed significant necrosis/fibrosis, avascularization, and glomerular atrophy in the immediate vicinity of the "9"0Y resin microspheres. By contrast, glomerular changes were not observed, even with clusters of bland microspheres in afferent arterioles. Evidence of a foreign body reaction was recorded in some kidneys with bland microspheres, and subcapsular scarring/infarction only with the highest load (4.96 × 10"6) of bland microspheres.ConclusionThis study showed that radioembolization with "9"0Y resin microspheres produces localized necrosis/fibrosis and loss of kidney mass in a porcine kidney model. This result supports the study of "9"0Y resin microspheres for the localized treatment of kidney tumors.

  12. Neutron transmission measurements on hydrogen filled microspheres

    International Nuclear Information System (INIS)

    Dyrnjaja, Eva; Hummel, Stefan; Keding, Marcus; Smolle, Marie-Theres; Gerger, Joachim; Zawisky, Michael

    2014-01-01

    Hollow microspheres are promising candidates for future hydrogen storage technologies. Although the physical process for hydrogen diffusion through glass is well understood, measurements of static quantities (e.q. hydrogen pressure inside the spheres) as well as dynamic properties (e.g. diffusion rate of hydrogen through glass) are still difficult to handle due to the small size of the spheres (d≈15μm). For diffusion rate measurements, the long-term stability of the experiment is also mandatory due to the relatively slow diffusion rate. In this work, we present an accurate and long-term stable measurement technique for static and dynamic properties, using neutron radiography. Furthermore, possible applications for hydrogen filled microspheres within the scope of radiation issues are discussed

  13. Optical Microspherical Resonators for Biomedical Sensing

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2011-01-01

    Full Text Available Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field.

  14. Aptamer Based Microsphere Biosensor for Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Xudong Fan

    2006-08-01

    Full Text Available We have developed an optical microsphere resonator biosensor using aptamer asreceptor for the measurement of the important biomolecule thrombin. The sphere surface ismodified with anti-thrombin aptamer, which has excellent binding affinity and selectivityfor thrombin. Binding of the thrombin at the sphere surface is monitored by the spectralposition of the microsphere’s whispering gallery mode resonances. A detection limit on theorder of 1 NIH Unit/mL is demonstrated. Control experiments with non-aptameroligonucleotide and BSA are also carried out to confirm the specific binding betweenaptamer and thrombin. We expect that this demonstration will lead to the development ofhighly sensitive biomarker sensors based on aptamer with lower cost and higher throughputthan current technology.

  15. Sputter coating of microspherical substrates by levitation

    Science.gov (United States)

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  16. Glass microspheres covering film: first field evaluations

    International Nuclear Information System (INIS)

    Magnani, G.; Filippi, F.

    2006-01-01

    A trial was carried out to evaluate, in the North-Centre of Italy, the behaviour in field of a new plastic covering film, prepared with the inclusion of empty glass microspheres (Solex). The trial was conducted on tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). The new film was compared to a covering film with the same optical (diffuse light) and constitutional (co-extruded three layers EVA-WPE) characteristics. Since the first results, the innovative film showed a better behaviour than the control one. It presented light and thermal conditions (lower temperature during the day and slightly higher temperature in the night, compared to the control film) that allowed a better growth and yield than the control film. The growth analysis of tomato showed that plants grown under glass microsphere film had an higher growth rate (dry weight/days) and thickness of leaves compared to the control one. The yield of tomato and eggplant presented an increase in plants cultivated under the innovative film, especially for number and weight of fruits. The commercial quality did not show any differences between the films, except for the flesh hardness of tomato: this could be explained with the fact that the glass microspheres film provides environmental conditions avoiding plant stress during some stages of its cycle [it

  17. STRUCTURING OF DIAMOND FILMS USING MICROSPHERE LITHOGRAPHY

    Directory of Open Access Journals (Sweden)

    Mária Domonkos

    2014-10-01

    Full Text Available In this study, the structuring of micro- and nanocrystalline diamond thin films is demonstrated. The structuring of the diamond films is performed using the technique of microsphere lithography followed by reactive ion etching. Specifically, this paper presents a four-step fabrication process: diamond deposition (microwave plasma assisted chemical vapor deposition, mask preparation (by the standard Langmuir-Blodgett method, mask modification and diamond etching. A self-assembled monolayer of monodisperse polystyrene (PS microspheres with close-packed ordering is used as the primary template. Then the PS microspheres and the diamond films are processed in capacitively coupled radiofrequency plasma  using different plasma chemistries. This fabrication method illustrates the preparation of large arrays of periodic and homogeneous hillock-like structures. The surface morphology of processed diamond films is characterized by scanning electron microscopy and atomic force microscope. The potential applications of such diamond structures in various fields of nanotechnology are also briefly discussed.

  18. Yttrium-90 microsphere induced gastrointestinal tract ulceration

    Directory of Open Access Journals (Sweden)

    Rikabi Ali A

    2008-09-01

    Full Text Available Abstract Background Radiomicrosphere therapy (RT utilizing yttrium-90 (90Y microspheres has been shown to be an effective regional treatment for primary and secondary hepatic malignancies. We sought to determine a large academic institution's experience regarding the extent and frequency of gastrointestinal complications. Methods Between 2004 and 2007, 27 patients underwent RT for primary or secondary hepatic malignancies. Charts were subsequently reviewed to determine the incidence and severity of GI ulceration. Results Three patients presented with gastrointestinal bleeding and underwent upper endoscopy. Review of the pretreatment angiograms showed normal vascular anatomy in one patient, sclerosed hepatic vasculature in a patient who had undergone prior chemoembolization in a second, and an aberrant left hepatic artery in a third. None had undergone prophylactic gastroduodenal artery embolization. Endoscopic findings included erythema, mucosal erosions, and large gastric ulcers. Microspheres were visible on endoscopic biopsy. In two patients, gastric ulcers were persistent at the time of repeat endoscopy 1–4 months later despite proton pump inhibitor therapy. One elderly patient who refused surgical intervention died from recurrent hemorrhage. Conclusion Gastrointestinal ulceration is a known yet rarely reported complication of 90Y microsphere embolization with potentially life-threatening consequences. Once diagnosed, refractory ulcers should be considered for aggressive surgical management.

  19. Adsorption behavior of protein onto siloxane microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Liu Bailing [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)]. E-mail: Blliuchem@hotmail.com; Cao Shunsheng [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Deng Xiaobo [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Li Songjun [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China); Luo Rong [Chengdu Institute of Organic Chemistry, Graduate School of CAS, Chinese Academy of Sciences, Chengdu 610041 (China)

    2006-09-15

    The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption.

  20. Adsorption behavior of protein onto siloxane microspheres

    International Nuclear Information System (INIS)

    Liu Bailing; Cao Shunsheng; Deng Xiaobo; Li Songjun; Luo Rong

    2006-01-01

    The siloxane microspheres with core-shell structure (PMMA/PMPS) (MMA, methyl methacrylate; MPS, 3-methacryloxypropyl-trimethoxysilane) have been prepared by dispersion polymerization as described in our previous work. In this paper, the developed poly(MMA-MPS) microspheres, as a carrier, are used to investigate the adsorption behavior of bovine serum albumin (BSA) on them. The Langmuir and Freundlich models have been applied to describe the adsorption behavior. The experimental results indicated that the presence of PMPS evidently increases the adsorption rate and the amount of protein, and it also influences the interaction of BSA molecules. The adsorption of BSA on the poly(MMA-MPS) microspheres seems to be sensitive to pH and ionic strength. The fittings curves from Langmuir and Freundlich models showed that the adsorption was actually more complicated than ideal situation because one or more interactions were involved in the process. For understanding the electronic contribution, the Zeta potential was used to measure the reactive system before and after protein adsorption

  1. Antiplasmodial Activity and Toxicological Assessment of Curcumin PLGA-Encapsulated Nanoparticles

    Science.gov (United States)

    Busari, Zulaikha A.; Dauda, Kabiru A.; Morenikeji, Olajumoke A.; Afolayan, Funmilayo; Oyeyemi, Oyetunde T.; Meena, Jairam; Sahu, Debasis; Panda, Amulya K.

    2017-01-01

    Curcumin is a polyphenolic pigment isolated from the rhizomes of Curcuma longa (turmeric), a medicinal plant widely used in the ancient Indian and Chinese medicine. The antiplasmodial activity of curcumin is often hampered by its fast metabolism and poor water solubility, thus its incorporation into a delivery system could circumvent this problem. This study aimed to evaluate the in vivo antiplasmodial activity and the toxicity assessment of curcumin incorporated into poly (lactic-co-glycolic) acid (PLGA) nanoparticles. Curcumin was loaded with poly (D,L-lactic-co-glycolic acid) (PLGA) using solvent evaporation from oil-in-water single emulsion method. The nanoparticles were characterized and evaluated in vivo for antimalarial activities using Peter’s 4-day suppressive protocol in mice model. Hematological and hepatic toxicity assays were performed on whole blood and plasma, respectively. In vivo anti-parasitic test and toxicity assays for free and encapsulated drug were performed at 5 and 10 mg/kg. In vitro cytotoxicity of free and PLGA encapsulated curcumin (Cur-PLGA) to RAW 264.7 cell line was also determined at varying concentrations (1000–7.8 μg/mL). The size and entrapment efficiency of the nanoparticulate drug formulated was 291.2 ± 82.1 nm and 21.8 ± 0.4 respectively. The percentage parasite suppression (56.8%) at 5 mg/kg was significantly higher than in free drug (40.5%) of similar concentration (p 0.05) except in lymphocytes which were significantly higher in Cur-PLGA compared to the free drug (p 0.05). At higher concentrations (1000 and 500 μg/mL), Cur-PLGA entrapped nanoparticle showed higher toxicity compared with the free drug (p 0.05). The antiplasmodial activity and safety of Cur-PLGA was better at lower concentration. PMID:28932197

  2. Effects of chemically modified nanostructured PLGA on functioning of lung and breast cancer cells

    Directory of Open Access Journals (Sweden)

    Zhang L

    2013-05-01

    Full Text Available Lijuan Zhang,1 Thomas J Webster21Department of Chemistry, 2School of Engineering, Brown University, Providence, RI, USABackground: The aim of this study was to investigate the effects of poly-lactic-co-glycolic acid (PLGA nanotopographies with alginate or chitosan protein preadsorption on the functioning of healthy and cancerous lung and breast cells, including adhesion, proliferation, apoptosis, and release of vascular endothelial growth factor (VEGF, which promotes tumor angiogenesis and secretion.Methods: We used a well established cast-mold technique to create nanoscale surface features on PLGA. Some of the nanomodified PLGA films were then exposed to alginate and chitosan. Surface roughness and the presence of protein was confirmed by atomic force microscopy. Surface energy was quantified by contact angle measurement.Results: Nanostructured PLGA surfaces with 23 nm features decreased synthesis of VEGF in both lung and breast cancer cells compared with conventional PLGA. Preadsorbing alginate further decreased cancer cell function, with nanostructured PLGA preadsorbed with alginate achieving the greatest decrease in synthesis of VEGF in both lung and breast cancer cells. In contrast, compared with nonmodified smooth PLGA, healthy cell functions were either not altered (ie, breast or were enhanced (ie, lung by use of nanostructured features and alginate or chitosan protein preadsorption.Conclusion: Using this technique, we developed surface nanometric roughness and modification of surface chemistry that could selectively decrease breast and lung cancer cell functioning without the need for chemotherapeutics. This technique requires further study in a wide range of anticancer and regenerative medicine applications.Keywords: breast, lung, cancer, nanotechnology, alginate, chitosan

  3. Micro/Nano Multilayered Scaffolds of PLGA and Collagen by Alternately Electrospinning for Bone Tissue Engineering

    Science.gov (United States)

    Kwak, Sanghwa; Haider, Adnan; Gupta, Kailash Chandra; Kim, Sukyoung; Kang, Inn-Kyu

    2016-07-01

    The dual extrusion electrospinning technique was used to fabricate multilayered 3D scaffolds by stacking microfibrous meshes of poly(lactic acid-co-glycolic acid) (PLGA) in alternate fashion to micro/nano mixed fibrous meshes of PLGA and collagen. To fabricate the multilayered scaffold, 35 wt% solution of PLGA in THF-DMF binary solvent (3:1) and 5 wt% solution of collagen in hexafluoroisopropanol (HFIP) with and without hydroxyapatite nanorods (nHA) were used. The dual and individual electrospinning of PLGA and collagen were carried out at flow rates of 1.0 and 0.5 mL/h, respectively, at an applied voltage of 20 kV. The density of collagen fibers in multilayered scaffolds has controlled the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells. The homogeneous dispersion of glutamic acid-modified hydroxyapatite nanorods (nHA-GA) in collagen solution has improved the osteogenic properties of fabricated multilayered scaffolds. The fabricated multilayered scaffolds were characterized using FT-IR, X-ray photoelectron spectroscopy, and transmission electron microscopy (TEM). The scanning electron microscopy (FE-SEM) was used to evaluate the adhesion and spreads of MC3T3-E1 cells on multilayered scaffolds. The activity of MC3T3-E1 cells on the multilayered scaffolds was evaluated by applying MTT, alkaline phosphatase, Alizarin Red, von Kossa, and cytoskeleton F-actin assaying protocols. The micro/nano fibrous PLGA-Col-HA scaffolds were found to be highly bioactive in comparison to pristine microfibrous PLGA and micro/nano mixed fibrous PLGA and Col scaffolds.

  4. Preparation, characterization and immunological evaluation: canine parvovirus synthetic peptide loaded PLGA nanoparticles.

    Science.gov (United States)

    Derman, Serap; Mustafaeva, Zeynep Akdeste; Abamor, Emrah Sefik; Bagirova, Melahat; Allahverdiyev, Adil

    2015-10-20

    Canine parvovirus 2 (CPV-2) remains a significant worldwide canine pathogen and the most common cause of viral enteritis in dogs. The 1 L15 and 7 L15 peptides overlap each other with QPDGGQPAV residues (7-15 of VP2 capsid protein of CPV) is shown to produce high immune response. PLGA nanoparticles were demonstrated to have special properties such as; controlled antigen release, protection from degradation, elimination of booster-dose and enhancing the cellular uptake by antigen presenting cells. Nevertheless, there is no study available in literature, about developing vaccine based on PLGA nanoparticles with adjuvant properties against CPV. Thus, the aim of the present study was to synthesize and characterize high immunogenic W-1 L19 peptide (from the VP2 capsid protein of CPV) loaded PLGA nanoparticle and to evaluate their in vitro immunogenic activity. PLGA nanoparticles were produced with 5.26 ± 0.05 % loading capacity and high encapsulation efficiency with 81.2 ± 3.1 %. Additionally, it was evaluated that free NPs and W-1 L19 peptide encapsulated PLGA nanoparticles have Z-ave of 183.9 ± 12.1 nm, 221.7 ± 15.8 nm and polydispersity index of 0.107 ± 0.08, 0.135 ± 0.12 respectively. It was determined that peptide loaded PLGA nanoparticles were successfully phagocytized by macrophage cells and increased NO production at 2-folds (*P vaccine candidate against Canine Parvovirus. Studies targeting PLGA nanoparticles based delivery system must be maintained in near future in order to develop new and more effective nano-vaccine formulations.

  5. Utility of the dimercapto succinic acid pentavalent (99m Tc- DMSA V) in the diagnostic of secondary bone leisure at metastasis of diverse primary tumours. Preliminary study

    International Nuclear Information System (INIS)

    Ortega L, N.; Pichardo R, P.A.; Marquez H, A.

    2005-01-01

    The more used method in the diagnosis of secondary bone lesions to become cancerous it is by means of having derived of phosphates like it is the 99m Tc- MDP. The reason of acquiring searching with the radiopharmaceutical 99m Tc- DMSA V is with the purpose to find other bone lesions that are not visualized with the gammagraphy with diphosphonate and therefore to increase the specificity of the study. (Author)

  6. Evaluation of a combined drug-delivery system for proteins assembled with polymeric nanoparticles and porous microspheres; characterization and protein integrity studies.

    Science.gov (United States)

    Alcalá-Alcalá, Sergio; Benítez-Cardoza, Claudia G; Lima-Muñoz, Enrique J; Piñón-Segundo, Elizabeth; Quintanar-Guerrero, David

    2015-07-15

    This work presents an evaluation of the adsorption/infiltration process in relation to the loading of a model protein, α-amylase, into an assembled biodegradable polymeric system, free of organic solvents and made up of poly(D,L-lactide-co-glycolide) acid (PLGA). Systems were assembled in a friendly aqueous medium by adsorbing and infiltrating polymeric nanoparticles into porous microspheres. These assembled systems are able to load therapeutic amounts of the drug through adsorption of the protein onto the large surface area characteristic of polymeric nanoparticles. The subsequent infiltration of nanoparticles adsorbed with the protein into porous microspheres enabled the controlled release of the protein as a function of the amount of infiltrated nanoparticles, since the surface area available on the porous structure is saturated at different levels, thus modifying the protein release rate. Findings were confirmed by both the BET technique (N2 isotherms) and in vitro release studies. During the adsorption process, the pH of the medium plays an important role by creating an environment that favors adsorption between the surfaces of the micro- and nano-structures and the protein. Finally, assays of α-amylase activity using 2-chloro-4-nitrophenyl-α-D-maltotrioside (CNP-G3) as the substrate and the circular dichroism technique confirmed that when this new approach was used no conformational changes were observed in the protein after release. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Endocytic pathways involved in PLGA nanoparticle uptake by grapevine cells and role of cell wall and membrane in size selection.

    Science.gov (United States)

    Palocci, Cleofe; Valletta, Alessio; Chronopoulou, Laura; Donati, Livia; Bramosanti, Marco; Brasili, Elisa; Baldan, Barbara; Pasqua, Gabriella

    2017-12-01

    PLGA NPs' cell uptake involves different endocytic pathways. Clathrin-independent endocytosis is the main internalization route. The cell wall plays a more prominent role than the plasma membrane in NPs' size selection. In the last years, many studies on absorption and cell uptake of nanoparticles by plants have been conducted, but the understanding of the internalization mechanisms is still largely unknown. In this study, polydispersed and monodispersed poly(lactic-co-glycolic) acid nanoparticles (PLGA NPs) were synthesized, and a strategy combining the use of transmission electron microscopy (TEM), confocal analysis, fluorescently labeled PLGA NPs, a probe for endocytic vesicles (FM4-64), and endocytosis inhibitors (i.e., wortmannin, ikarugamycin, and salicylic acid) was employed to shed light on PLGA NP cell uptake in grapevine cultured cells and to assess the role of the cell wall and plasma membrane in size selection of PLGA NPs. The ability of PLGA NPs to cross the cell wall and membrane was confirmed by TEM and fluorescence microscopy. A strong adhesion of PLGA NPs to the outer side of the cell wall was observed, presumably due to electrostatic interactions. Confocal microscopy and treatment with endocytosis inhibitors suggested the involvement of both clathrin-dependent and clathrin-independent endocytosis in cell uptake of PLGA NPs and the latter appeared to be the main internalization pathway. Experiments on grapevine protoplasts revealed that the cell wall plays a more prominent role than the plasma membrane in size selection of PLGA NPs. While the cell wall prevents the uptake of PLGA NPs with diameters over 50 nm, the plasma membrane can be crossed by PLGA NPs with a diameter of 500-600 nm.

  8. Tc-99m DTPA and Tc-99m DMSA renal scan findings in patients with congenital megacalyces and megaureter without urinary tract obstruction

    International Nuclear Information System (INIS)

    Ahn, Byeong Cheol; Bae, Jin Ho; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo

    2003-01-01

    A 10 days old male infant with congenital megacalyces and megaureter, diagnosed by prenatal ultrasonographic screening, underwent Tc-99m DTPA renal scan for evaluation of urinary tract patency, Tc-99m DMSA scan for evaluation of renal cortical damage. He also underwent intravenous urography(IVU) and renal ultrasonography. Tc-99m DTPA renal scan demonstrates intense tracer accumulation in enlarged both renal pelvocalyses and ureters, which rapidly washout diuretics administration. Tc-99m DMSA renal cortical scan shows no remarkable photon defect in both renal cortices and visible tracer uptake in both megaureter areas. Ultasonographic and IVU studies show enlarged both renal calyses and bullously dilated ureters, but no dilatation in renal pelvis. Follow up Tc-99m DTPA renal scan, performed at one year later, also reveals intense tracer accumulation in enlarged both urinary tracts which rapidly washout without diuretics, and shows no significant change compare to the previous Tc-99m DTPA renal scan. Urinary tract obstruction and renal cortical damage can be easily evaluated with Tc-99m DTPA and Tc-99m DMSA scans in patients with megacalyces and megaureter

  9. An experimental study on recovery of renal function using {sup 99m}Tc DMSA scintigram after percutaneous nephrostomy in unilateral hydronephrosis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Tae Yong; Nam, Sang Hwa; Park, Jong Yeon; Kim, Byung Soo [College of Medicine, Pusan National University, Pusan (Korea, Republic of)

    1992-07-15

    Obstruction on the urinary tract eventually results in damage to the kidneys and lose of function. The questions that concern the clinician are the degree of nephron loss in that kidney and potential for recovery following the relief of obstruction. {sup 99m}Tc DMSA accumulates in tubule cells and has been proposed as a marker of the tubular mass. The authors estimated the renal uptake ratio of {sup 99m}Tc DMSA for the degree of nephron loss corresponding to duration of hydronephrosis following left ureteral ligation in 5 New Zealand white rabbits and the potential for recovery following percutaneous nephrostomy of hydronephrosis in 24 rabbits. While the renal uptake ratio of {sup 99m}Tc DMSA of the kidney with unilateral hydronephrosis following ureteral ligation reduced dramatically within 24 hour, that of the opposite healthy kidney increased, and the total renal uptake ratio was same as normal functioning kidneys before ureteral ligation. Upon ureteral release, there was no evidence of definite recovery or impairment in the experimental kidneys for 5 days. The authors conclude that a combination of ureteral release and administration of some drugs such as renal vasodilator or diuretics is an appropriate treatment for the recovery of function in unilateral hydronephrosis.

  10. Tc-99m DTPA and Tc-99m DMSA renal scan findings in patients with congenital megacalyces and megaureter without urinary tract obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byeong Cheol; Bae, Jin Ho; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo [Kyungpook National University Medical School, Daegu (Korea, Republic of)

    2003-06-01

    A 10 days old male infant with congenital megacalyces and megaureter, diagnosed by prenatal ultrasonographic screening, underwent Tc-99m DTPA renal scan for evaluation of urinary tract patency, Tc-99m DMSA scan for evaluation of renal cortical damage. He also underwent intravenous urography(IVU) and renal ultrasonography. Tc-99m DTPA renal scan demonstrates intense tracer accumulation in enlarged both renal pelvocalyses and ureters, which rapidly washout diuretics administration. Tc-99m DMSA renal cortical scan shows no remarkable photon defect in both renal cortices and visible tracer uptake in both megaureter areas. Ultasonographic and IVU studies show enlarged both renal calyses and bullously dilated ureters, but no dilatation in renal pelvis. Follow up Tc-99m DTPA renal scan, performed at one year later, also reveals intense tracer accumulation in enlarged both urinary tracts which rapidly washout without diuretics, and shows no significant change compare to the previous Tc-99m DTPA renal scan. Urinary tract obstruction and renal cortical damage can be easily evaluated with Tc-99m DTPA and Tc-99m DMSA scans in patients with megacalyces and megaureter.

  11. Evaluation of the protective effect of agmatine against cisplatin nephrotoxicity with 99mTc-DMSA renal scintigraphy and cystatin-C.

    Science.gov (United States)

    Salihoglu, Yavuz Sami; Elri, Tarik; Gulle, Kanat; Can, Murat; Aras, Mustafa; Ozacmak, Hale Sayan; Cabuk, Mehmet

    2016-10-01

    The aim of the current study was to investigate whether agmatine (AGM) has a protective effect against cisplatin-induced nephrotoxicity. Thirty-two rats were randomly divided into four groups: (1) Saline (control); (2) Cisplatin (CDDP; 7.5 mg/kg intraperitoneally); (3) Agmatine (AGM; 10 mg/kg intraperitoneally); (4) Cisplatin plus agmatine (CDDP + AGM). Agmatine was given before and two consecutive days after cisplatin injection. All the animals underwent renal scintigraphy with 99mTc-DMSA. The levels of serum creatinine, cystatin C, and blood urea nitrogen (BUN) were measured in addition to examination of the tissue samples with light microscopy. Acute renal injury was assessed with biochemical analyses, scintigraphic imaging, and histopathological evaluation. In the cisplatin group, the levels of BUN, creatinine, and cystatin C were significantly higher than that of the controls. Histopathological examination showed remarkable damage of tubular and glomerular structures. Additionally, cisplatin caused markedly decreased renal 99mTc-DMSA uptake. AGM administration improved renal functions. Serum creatinine, BUN, and cystatin C levels had a tendency to normalize and, scintigraphic and histopathological findings showed significantly less evidence of renal toxicity than those observed in animals receiving cisplatin alone. Our data indicate that AGM has a protective effect against cisplatin-induced nephrotoxicity. Therefore, it may improve the therapeutic index of cisplatin. In addition, the early renal damage induced by cisplatin and protective effects of AGM against cisplatin nephrotoxicity was accurately demonstrated with 99mTc-DMSA renal scintigraphy.

  12. An experimental study on recovery of renal function using 99mTc DMSA scintigram after percutaneous nephrostomy in unilateral hydronephrosis

    International Nuclear Information System (INIS)

    Moon, Tae Yong; Nam, Sang Hwa; Park, Jong Yeon; Kim, Byung Soo

    1992-01-01

    Obstruction on the urinary tract eventually results in damage to the kidneys and lose of function. The questions that concern the clinician are the degree of nephron loss in that kidney and potential for recovery following the relief of obstruction. 99m Tc DMSA accumulates in tubule cells and has been proposed as a marker of the tubular mass. The authors estimated the renal uptake ratio of 99m Tc DMSA for the degree of nephron loss corresponding to duration of hydronephrosis following left ureteral ligation in 5 New Zealand white rabbits and the potential for recovery following percutaneous nephrostomy of hydronephrosis in 24 rabbits. While the renal uptake ratio of 99m Tc DMSA of the kidney with unilateral hydronephrosis following ureteral ligation reduced dramatically within 24 hour, that of the opposite healthy kidney increased, and the total renal uptake ratio was same as normal functioning kidneys before ureteral ligation. Upon ureteral release, there was no evidence of definite recovery or impairment in the experimental kidneys for 5 days. The authors conclude that a combination of ureteral release and administration of some drugs such as renal vasodilator or diuretics is an appropriate treatment for the recovery of function in unilateral hydronephrosis

  13. Evaluation of the absorbed dose to the kidneys due to Tc99m (DTPA) / Tc99m (Mag3) and Tc99m (Dmsa)

    International Nuclear Information System (INIS)

    Vasquez A, M.; Murillo C, F.; Castillo D, C.; Rocha J, J.; Sifuentes D, Y.; Sanchez S, P.; Idrogo C, J.; Marquez P, F.

    2015-10-01

    The absorbed dose in the kidneys of adult patients has been assessed using the biokinetics of radiopharmaceuticals containing Tc 99m (DTPA) / Tc 99m (Mag3) or Tc 99m (Dmsa).The absorbed dose was calculated using the formalism MIRD and the Cristy-Eckerman representation for the kidneys. The absorbed dose to the kidneys due to Tc 99m (DTPA) / Tc 99m (Mag3), are given by 0.00466 mGy.MBq -1 / 0.00339 mGy.MBq -1 . Approximately 21.2% of the absorbed dose is due to the bladder (content) and the remaining tissue, included in biokinetics of Tc 99m (DTPA) / Tc 99m (Mag3). The absorbed dose to the kidneys due to Tc 99m (Dmsa) is 0.17881 mGy.MBq -1 . Here, 1.7% of the absorbed dose is due to the bladder, spleen, liver and the remaining tissue, included in biokinetics of Tc 99m (Dmsa). (Author)

  14. Influences of renal stone surgeries on renal function; Evaluation of renal function with sup 99m Tc-DMSA renal scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, Yasushi (Niigata Univ. (Japan). School of Medicine)

    1991-10-01

    From 1984 to 1990, {sup 99m}Tc-DMSA renal scintigraphy was performed before and after nephrolithotomy (15 cases), pyelolithotomy (15 cases), percutaneous nephrolithotripsy (PNL: 15 cases) and extracorporeal shock wave lithotripsy (ESWL: 16 cases, 17 kidneys) in order to evaluate of influences of renal stone surgeries on split renal function. DMSA renal uptake change ratio of treated kidneys of nephrolithotomy (-24.94{+-}5.60%) was significantly lower than that of PNL (-0.06{+-}3.92%), pyelolithotomy (-4.08{+-}4.79%) (p<0.01) and ESWL (-7.72{+-}3.87%) (p<0.05). The average change ratios of contralateral kidneys were as follows: PNL 4.80{+-}4.21% nephrolithotomy 4.67{+-}4.73%, pyelolithotomy -1.46{+-}5.39% and ESWL -2.02{+-}4.44%. One to 3 weeks after PNL, the cold area on the renal image was found in 10 (66.7%) of 15 cases. In cases of ESWL, DMSA renal uptake decreased even 4-10 weeks (mean 7 weeks) after treatment. In conclusion, possibility of deterioration of renal function after ESWL was suggested. (author).

  15. Antiplasmodial Activity and Toxicological Assessment of Curcumin PLGA-Encapsulated Nanoparticles

    Directory of Open Access Journals (Sweden)

    Zulaikha A. Busari

    2017-09-01

    Full Text Available Curcumin is a polyphenolic pigment isolated from the rhizomes of Curcuma longa (turmeric, a medicinal plant widely used in the ancient Indian and Chinese medicine. The antiplasmodial activity of curcumin is often hampered by its fast metabolism and poor water solubility, thus its incorporation into a delivery system could circumvent this problem. This study aimed to evaluate the in vivo antiplasmodial activity and the toxicity assessment of curcumin incorporated into poly (lactic-co-glycolic acid (PLGA nanoparticles. Curcumin was loaded with poly (D,L-lactic-co-glycolic acid (PLGA using solvent evaporation from oil-in-water single emulsion method. The nanoparticles were characterized and evaluated in vivo for antimalarial activities using Peter’s 4-day suppressive protocol in mice model. Hematological and hepatic toxicity assays were performed on whole blood and plasma, respectively. In vivo anti-parasitic test and toxicity assays for free and encapsulated drug were performed at 5 and 10 mg/kg. In vitro cytotoxicity of free and PLGA encapsulated curcumin (Cur-PLGA to RAW 264.7 cell line was also determined at varying concentrations (1000–7.8 μg/mL. The size and entrapment efficiency of the nanoparticulate drug formulated was 291.2 ± 82.1 nm and 21.8 ± 0.4 respectively. The percentage parasite suppression (56.8% at 5 mg/kg was significantly higher than in free drug (40.5% of similar concentration (p < 0.05 but not at 10 mg/kg (49.5% at 4-day post-treatment. There were no significant differences in most of the recorded blood parameters in free curcumin and PLGA encapsulated nanoparticulate form (p > 0.05 except in lymphocytes which were significantly higher in Cur-PLGA compared to the free drug (p < 0.05. There were no significant differences in hepatotoxic biomarkers; aspartate aminotransferase and alanine aminotransferase concentrations in various treatment groups (p > 0.05. At higher concentrations (1000 and 500 μg/mL, Cur-PLGA

  16. Bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles as novel tumor targeting carriers

    International Nuclear Information System (INIS)

    Ding Hong; Yong, Ken-Tye; Roy, Indrajit; Hu Rui; Zhao Lingling; Law, Wing-Cheung; Ji Wei; Liu Liwei; Bergey, Earl J; Prasad, Paras N; Wu Fang; Zhao Weiwei

    2011-01-01

    In this study, we have developed a novel carrier, micelle-type bioconjugated PLGA-4-arm-PEG branched polymeric nanoparticles (NPs), for the detection and treatment of pancreatic cancer. These NPs contained 4-arm-PEG as corona, and PLGA as core, the particle surface was conjugated with cyclo(arginine-glycine-aspartate) (cRGD) as ligand for in vivo tumor targeting. The hydrodynamic size of the NPs was determined to be 150-180 nm and the critical micellar concentration (CMC) was estimated to be 10.5 mg l -1 . Our in vitro study shows that these NPs by themselves had negligible cytotoxicity to human pancreatic cancer (Panc-1) and human glioblastoma (U87) cell lines. Near infrared (NIR) microscopy and flow cytometry demonstrated that the cRGD conjugated PLGA-4-arm-PEG polymeric NPs were taken up more efficiently by U87MG glioma cells, over-expressing the α v β 3 integrin, when compared with the non-targeted NPs. Whole body imaging showed that the cRGD conjugated PLGA-4-arm-PEG branched polymeric NPs had the highest accumulation in the pancreatic tumor site of mice at 48 h post-injection. Physical, hematological, and pathological assays indicated low in vivo toxicity of this NP formulation. These studies on the ability of these bioconjugated PLGA-4-arm-PEG polymeric NPs suggest that the prepared polymeric NPs may serve as a promising platform for detection and targeted drug delivery for pancreatic cancer.

  17. A Comparative Cytotoxic Evaluation of Disulfiram Encapsulated PLGA Nanoparticles on MCF-7 Cells.

    Science.gov (United States)

    Fasehee, Hamidreza; Ghavamzadeh, Ardeshir; Alimoghaddam, Kamran; Ghaffari, Seyed-Hamidollah; Faghihi, Shahab

    2017-04-01

    Background: Disulfiram is oral aldehyde dehydrogenase (ALDH) inhibitor that has been used in the treatment of alcoholism. Recent studies show that this drug has anticancer properties; however, its rapid degradation has limited its clinical application. Encapsulation of disulfiram polymeric nanoparticles (NPs) may improve its anticancer activities and protect rapid degradation of the drug. Materials and Methods: A poly (lactide-co-Glycolide) (PLGA) was developed for encapsulation of disulfiram and its delivery into breast cancer cells. Disulfiram encapsulated PLGA NPs were prepared by nanoprecipitation method and were characterized by Scanning Electron Microscopy (SEM). The loading and encapsulation efficiency of NPs were determined using UV-Visible spectroscopy. Cell cytotoxicity of free and encapsulated form of disulfiram is also determined using MTT assay. Results: Disulfiram encapsulated PLGA NPs had uniform size with 165 nm. Drug loading and entrapment efficiency were 5.35 ±0.03% and 58.85±1.01%. The results of MTT assay showed that disulfiram encapsulated PLGA NPs were more potent in induction of apoptosis compare to free disulfiram. Conclusion: Based on the results obtained in the present study it can be concluded that encapsulation of disulfiram with PLGA can protect its degradation in improve its cytotoxicity on breast cancer cells.

  18. Preformulation Studies of Bee Venom for the Preparation of Bee Venom-Loaded PLGA Particles

    Directory of Open Access Journals (Sweden)

    Min-Ho Park

    2015-08-01

    Full Text Available It is known that allergic people was potentially vulnerable to bee venom (BV, which can induce an anaphylactic shock, eventually leading to death. Up until recently, this kind of allergy was treated only by venom immunotherapy (VIT and its efficacy has been recognized worldwide. This treatment is practiced by subcutaneous injections that gradually increase the doses of the allergen. This is inconvenient for patients due to frequent injections. Poly (D,L-lactide-co-glycolide (PLGA has been broadly studied as a carrier for drug delivery systems (DDS of proteins and peptides. PLGA particles usually induce a sustained release. In this study, the physicochemical properties of BV were examined prior to the preparation of BV-loaded PLGA nanoparticles NPs. The content of melittin, the main component of BV, was 53.3%. When protected from the light BV was stable at 4 °C in distilled water, during 8 weeks. BV-loaded PLGA particles were prepared using dichloromethane as the most suitable organic solvent and two min of ultrasonic emulsification time. This study has characterized the physicochemical properties of BV for the preparation BV-loaded PLGA NPs in order to design and optimize a suitable sustained release system in the future.

  19. PLGA based drug delivery systems: Promising carriers for wound healing activity.

    Science.gov (United States)

    Chereddy, Kiran Kumar; Vandermeulen, Gaëlle; Préat, Véronique

    2016-03-01

    Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Current treatment options are limited and require repeated administrations which led to the development of new therapeutics to satisfy the unmet clinical needs. Many potent wound healing agents were discovered but most of them are fragile and/or sensitive to in vivo conditions. Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable polymer approved by food and drug administration and European medicines agency as an excipient for parenteral administrations. It is a well-established drug delivery system in various medical applications. The aim of the current review is to elaborate the applications of PLGA based drug delivery systems carrying different wound healing agents and also present PLGA itself as a wound healing promoter. PLGA carriers encapsulating drugs such as antibiotics, anti-inflammatory drugs, proteins/peptides, and nucleic acids targeting various phases/signaling cycles of wound healing, are discussed with examples. The combined therapeutic effects of PLGA and a loaded drug on wound healing are also mentioned. © 2016 by the Wound Healing Society.

  20. Efficacy of piroxicam plus cisplatin-loaded PLGA nanoparticles in inducing apoptosis in mesothelioma cells.

    Science.gov (United States)

    Menale, Ciro; Piccolo, Maria Teresa; Favicchia, Ilaria; Aruta, Maria Grazia; Baldi, Alfonso; Nicolucci, Carla; Barba, Vincenzo; Mita, Damiano Gustavo; Crispi, Stefania; Diano, Nadia

    2015-02-01

    Combined treatment based on cisplatin-loaded Poly(D,L-lactic-co-glicolic)acid (PLGA) nanoparticles (NP-C) plus the NSAID piroxicam was used as novel treatment for mesothelioma to reduce side effects related to cisplatin toxicity. PLGA nanoparticles were prepared by double emulsion solvent evaporation method. Particle size, drug release profile and in vitro cellular uptake were characterized by TEM, DLS, LC/MS and fluorescence microscopy. MSTO-211H cell line was used to analyse NP-C biological efficacy by FACS and protein analysis. Cisplatin was encapsulated in 197 nm PLGA nanoparticles with 8.2% drug loading efficiency and 47% encapsulation efficiency. Cisplatin delivery from nanoparticles reaches 80% of total encapsulated drug in 14 days following a triphasic trend. PLGA nanoparticles in MSTO-211H cells were localized in the perinuclear space NP-C in combination with piroxicam induced apoptosis using a final cisplatin concentration 1.75 fold less than free drug. Delivered cisplatin cooperated with piroxicam in modulating cell cycle regulators as caspase-3, p53 and p21. Cisplatin loaded PLGA nanoparticles plus piroxicam showed a good efficacy in exerting cytotoxic activity and inducing the same molecular apoptotic effects of the free drugs. Sustained cisplatin release allowed to use less amount of drug, decreasing toxic side effects. This novel approach could represent a new strategy for mesothelioma treatment.

  1. Preformulation Studies of Bee Venom for the Preparation of Bee Venom-Loaded PLGA Particles.

    Science.gov (United States)

    Park, Min-Ho; Kim, Ju-Heon; Jeon, Jong-Woon; Park, Jin-Kyu; Lee, Bong-Joo; Suh, Guk-Hyun; Cho, Cheong-Weon

    2015-08-18

    It is known that allergic people was potentially vulnerable to bee venom (BV), which can induce an anaphylactic shock, eventually leading to death. Up until recently, this kind of allergy was treated only by venom immunotherapy (VIT) and its efficacy has been recognized worldwide. This treatment is practiced by subcutaneous injections that gradually increase the doses of the allergen. This is inconvenient for patients due to frequent injections. Poly (D,L-lactide-co-glycolide) (PLGA) has been broadly studied as a carrier for drug delivery systems (DDS) of proteins and peptides. PLGA particles usually induce a sustained release. In this study, the physicochemical properties of BV were examined prior to the preparation of BV-loaded PLGA nanoparticles NPs). The content of melittin, the main component of BV, was 53.3%. When protected from the light BV was stable at 4 °C in distilled water, during 8 weeks. BV-loaded PLGA particles were prepared using dichloromethane as the most suitable organic solvent and two min of ultrasonic emulsification time. This study has characterized the physicochemical properties of BV for the preparation BV-loaded PLGA NPs in order to design and optimize a suitable sustained release system in the future.

  2. Controlling silk fibroin microspheres via molecular weight distribution

    International Nuclear Information System (INIS)

    Zeng, Dong-Mei; Pan, Jue-Jing; Wang, Qun; Liu, Xin-Fang; Wang, Hui; Zhang, Ke-Qin

    2015-01-01

    Silk fibroin (SF) microspheres were produced by salting out SF solution via the addition of potassium phosphate buffer solution (K 2 HPO 4 –KH 2 PO 4 ). The morphology, size and polydispersity of SF microspheres were adjusted by changing the molecular weight (MW) distribution and concentration of SF, as well as the ionic strength and pH of the buffer solution. Changing the conditions under which the SF fiber dissolved in the Lithium Boride (LiBr) solution resulted in altering the MW distribution of SF solution. Under optimal salting-out conditions (ionic strength > 0.7 M and pH > 7) and using a smaller and narrower SF MW distribution, SF microspheres with smoother shapes and more uniform sizes were produced. Meanwhile, the size and polydispersity of the microspheres increased when the SF concentration was increased from 0.25 mg/mL to 20 mg/mL. The improved SF microspheres, obtained by altering the distribution of molecular weight, have potential in drug and gene delivery applications. - Highlights: • MW distribution was changed by applying different dissolving methods of SF fiber. • Smaller and narrower MW distribution improves the quality of SF microspheres. • Size and polydispersity of microspheres increase as SF concentration increases. • Improved SF microspheres have potential in drug and gene delivery applications

  3. Toward quantum-limited position measurements using optically levitated microspheres

    International Nuclear Information System (INIS)

    Libbrecht, Kenneth G.; Black, Eric D.

    2004-01-01

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements

  4. Toward quantum-limited position measurements using optically levitated microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Libbrecht, Kenneth G.; Black, Eric D

    2004-01-26

    We propose the use of optically levitated microspheres as test masses in experiments aimed at reaching and potentially exceeding the standard quantum limit for position measurements. Optically levitated microspheres have low mass and are essentially free of suspension thermal noise, making them well suited for experimentally testing our understanding of quantum-limited measurements.

  5. Development and evaluation of floating microspheres of curcumin in ...

    African Journals Online (AJOL)

    Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence and to study their effect on alloxan-induced diabetic rats. Methods: Floating microsphere were prepared by emulsion-solvent diffusion method, using hydroxylpropyl methylcellulose, chitosan and Eudragit S 100 polymer in ...

  6. Development and Evaluation of Floating Microspheres of Curcumin ...

    African Journals Online (AJOL)

    Purpose: To prepare and evaluate floating microspheres of curcumin for prolonged gastric residence time and increased drug bioavailability. Methods: Floating microsphere were prepared by emulsion solvent diffusion method, using hydroxylpropyl methylcellulose (HPMC), ethyl cellulose (EC), Eudragit S 100 polymer in ...

  7. Preparation of mesoporous zirconia microspheres as inert matrix

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ting [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Wang, Chen; Lv, Jinlong [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China)

    2016-12-01

    Mesoporous zirconia microspheres, with a diameter of 900 μm, were prepared as an inert accelerator driven system (ADS) transmutation element matrix by the sol-gel method. The purpose of mesopores is to improve the adsorption capacity of inert matrix fuel (IMF) for minor actinides. The study indicated that the mesoporous zirconia performance was improved after the microspheres were hydrothermally treated at 150 °C, the specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g, and hydrothermal treatment avoided the cracking of the microspheres. Pre-decomposition of the organics during the hydrothermal process stabilized the mesoporous structure. The average pore diameter of mesoporous microsphere was 14.3 nm. - Highlights: • Mesoporous zirconia microspheres with a diameter of 900 μm were prepared as ADS transmutation element inert matrix. • The mesoporous performance was improved after the microspheres were hydrothermally treated at 150 °C. • The specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g. • The hydrothermal treatment could avoid the cracking of the microspheres. • The specific surface area of mesoporous microsphere was 61.28 m{sup 2}/g and the average pore diameter was 14.3 nm.

  8. Antibacterial activity of ciprofloxacin-loaded zein microsphere films

    International Nuclear Information System (INIS)

    Fu Jianxi; Wang Huajie; Zhou Yanqing; Wang Jinye

    2009-01-01

    Our aim was to produce an antibiotic-emitting coating composed of zein microspheres for the prevention of bacterial infection on implanted devices. Ciprofloxacin-loaded zein microspheres were prepared using a phase separation procedure, with particle sizes between 0.5 and 2 μm. Drug encapsulation and drug loading varied with the amount of both zein and ciprofloxacin, and the highest encapsulation efficiency was 8.27% (2 mg/ml ciprofloxacin and 20 mg/ml zein; n = 3). A ciprofloxacin-loaded zein microsphere film (CF-MS film) was generated via solvent evaporation. Continuous drug release from a trypsin-degraded microsphere film was observed for up to 28 days. The liberation of ciprofloxacin from the trypsin-degraded film and the biodegradation of the microsphere film were highly correlated. Proliferation assay of the growth of human umbilical vein endothelial cells (HUVECs) by the MTT method showed that the microsphere film had no toxicity when compared with cells grown on Corning culture plates alone and plates with a zein film alone. Quantification of bacteria adhesion showed that adhesion on the microsphere film is significantly suppressed. In addition, according to the results of bacterial growth tests, ciprofloxacin-loaded microsphere films maintained antibacterial activity for more than 6 days. In contrast, a control medium containing a zein film allowed constant bacterial growth. These results indicate that CF-MS films might be useful as antibacterial films on implanted devices.

  9. Apparatus for manufacturing ceramics microspheres for cementing applications

    NARCIS (Netherlands)

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The micro spheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about Illbs/g. The resultant cement slurry may then be

  10. Controlling silk fibroin microspheres via molecular weight distribution

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Dong-Mei; Pan, Jue-Jing; Wang, Qun; Liu, Xin-Fang; Wang, Hui [National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Zhang, Ke-Qin, E-mail: kqzhang@suda.edu.cn [National Engineering Laboratory for Modern Silk, College for Textile and Clothing Engineering, Soochow University, Suzhou, Jiangsu 215123 (China); Research Center of Cooperative Innovation for Functional Organic/Polymer Material Micro/Nanofabrication, Soochow University, Suzhou, Jiangsu 215123 (China)

    2015-05-01

    Silk fibroin (SF) microspheres were produced by salting out SF solution via the addition of potassium phosphate buffer solution (K{sub 2}HPO{sub 4}–KH{sub 2}PO{sub 4}). The morphology, size and polydispersity of SF microspheres were adjusted by changing the molecular weight (MW) distribution and concentration of SF, as well as the ionic strength and pH of the buffer solution. Changing the conditions under which the SF fiber dissolved in the Lithium Boride (LiBr) solution resulted in altering the MW distribution of SF solution. Under optimal salting-out conditions (ionic strength > 0.7 M and pH > 7) and using a smaller and narrower SF MW distribution, SF microspheres with smoother shapes and more uniform sizes were produced. Meanwhile, the size and polydispersity of the microspheres increased when the SF concentration was increased from 0.25 mg/mL to 20 mg/mL. The improved SF microspheres, obtained by altering the distribution of molecular weight, have potential in drug and gene delivery applications. - Highlights: • MW distribution was changed by applying different dissolving methods of SF fiber. • Smaller and narrower MW distribution improves the quality of SF microspheres. • Size and polydispersity of microspheres increase as SF concentration increases. • Improved SF microspheres have potential in drug and gene delivery applications.

  11. Porous-wall hollow glass microspheres as carriers for biomolecules

    Science.gov (United States)

    Li, Shuyi; Dynan, William S; Wicks, George; Serkiz, Steven

    2013-09-17

    The present invention includes compositions of porous-wall hollow glass microspheres and one or more biomolecules, wherein the one or more biomolecules are positioned within a void location within the hollow glass microsphere, and the use of such compositions for the diagnostic and/or therapeutic delivery of biomolecules.

  12. Antibacterial activity of ciprofloxacin-loaded zein microsphere films

    Energy Technology Data Exchange (ETDEWEB)

    Fu Jianxi [Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032 (China); Henan Normal University, 46 East Construction Road, Xinxiang, Henan 453007 (China); Wang Huajie [College of Life Science and Biotechnology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China); Zhou Yanqing [Henan Normal University, 46 East Construction Road, Xinxiang, Henan 453007 (China); Wang Jinye, E-mail: jywang@mail.sioc.ac.cn [Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032 (China); College of Life Science and Biotechnology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030 (China)

    2009-05-05

    Our aim was to produce an antibiotic-emitting coating composed of zein microspheres for the prevention of bacterial infection on implanted devices. Ciprofloxacin-loaded zein microspheres were prepared using a phase separation procedure, with particle sizes between 0.5 and 2 {mu}m. Drug encapsulation and drug loading varied with the amount of both zein and ciprofloxacin, and the highest encapsulation efficiency was 8.27% (2 mg/ml ciprofloxacin and 20 mg/ml zein; n = 3). A ciprofloxacin-loaded zein microsphere film (CF-MS film) was generated via solvent evaporation. Continuous drug release from a trypsin-degraded microsphere film was observed for up to 28 days. The liberation of ciprofloxacin from the trypsin-degraded film and the biodegradation of the microsphere film were highly correlated. Proliferation assay of the growth of human umbilical vein endothelial cells (HUVECs) by the MTT method showed that the microsphere film had no toxicity when compared with cells grown on Corning culture plates alone and plates with a zein film alone. Quantification of bacteria adhesion showed that adhesion on the microsphere film is significantly suppressed. In addition, according to the results of bacterial growth tests, ciprofloxacin-loaded microsphere films maintained antibacterial activity for more than 6 days. In contrast, a control medium containing a zein film allowed constant bacterial growth. These results indicate that CF-MS films might be useful as antibacterial films on implanted devices.

  13. Formulation and Evaluation of Microspheres Based on Gelatin ...

    African Journals Online (AJOL)

    Formulation and Evaluation of Microspheres Based on Gelatin-Mucin Admixtures for the Rectal Delivery of Cefuroxime Sodium. K C Ofokansi, M U Adikwu. Abstract. Purpose: Swellable microspheres based on polymers or their admixtures are frequently employed as drug delivery systems to achieve a controlled release ...

  14. Microspheres with Ultrahigh Holmium Content for Radioablation of Malignancies

    NARCIS (Netherlands)

    Bult, W.; Seevinck, P.R.; Krijger, G.C.; Visser, T.; Kroon-Batenburg, L.M.J.; Bakker, C.J.G.; Hennink, W.E.; van het Schip, A.D.; Nijsen, J.F.W.

    2009-01-01

    The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  15. Microspheres with ultrahigh holmium content for radioablation of malignancies

    NARCIS (Netherlands)

    Bult, W; Seevinck, P R; Krijger, G C; Visser, T; Kroon-Batenburg, L M J; Bakker, C J G; Hennink, W E; van het Schip, A D; Nijsen, J F W

    PURPOSE: The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  16. Microspheres with Ultrahigh Holmium Content for Radioablation of Malignancies

    NARCIS (Netherlands)

    Bult, W.; Seevinck, P.R.; Krijger, G.C.; Visser, T.; Kroon-Batenburg, L.M.J.; Bakker, C.J.G.; Hennink, W.E.; Van het Schip, A.D.; Nijsen, J.F.W.

    Purpose The aim of this study was to develop microspheres with an ultra high holmium content which can be neutron activated for radioablation of malignancies. These microspheres are proposed to be delivered selectively through either intratumoral injections into solid tumors or administered via an

  17. Mn2+-coordinated PDA@DOX/PLGA nanoparticles as a smart theranostic agent for synergistic chemo-photothermal tumor therapy.

    Science.gov (United States)

    Xi, Juqun; Da, Lanyue; Yang, Changshui; Chen, Rui; Gao, Lizeng; Fan, Lei; Han, Jie

    2017-01-01

    Nanoparticle drug delivery carriers, which can implement high performances of multi-functions, are of great interest, especially for improving cancer therapy. Herein, we reported a new approach to construct Mn 2+ -coordinated doxorubicin (DOX)-loaded poly(lactic- co -glycolic acid) (PLGA) nanoparticles as a platform for synergistic chemo-photothermal tumor therapy. DOX-loaded PLGA (DOX/PLGA) nanoparticles were first synthesized through a double emulsion-solvent evaporation method, and then modified with polydopamine (PDA) through self-polymerization of dopamine, leading to the formation of PDA@DOX/PLGA nanoparticles. Mn 2+ ions were then coordinated on the surfaces of PDA@DOX/PLGA to obtain Mn 2+ -PDA@DOX/PLGA nanoparticles. In our system, Mn 2+ -PDA@DOX/PLGA nanoparticles could destroy tumors in a mouse model directly, by thermal energy deposition, and could also simulate the chemotherapy by thermal-responsive delivery of DOX to enhance tumor therapy. Furthermore, the coordination of Mn 2+ could afford the high magnetic resonance (MR) imaging capability with sensitivity to temperature and pH. The results demonstrated that Mn 2+ -PDA@ DOX/PLGA nanoparticles had a great potential as a smart theranostic agent due to their imaging and tumor-growth-inhibition properties.

  18. Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jin Cheng [Fourth Military Medical University, Department of Radiation Medicine (China); Bai Ling [Xi' an Gaoxin Hospital, Department of Clinical Laboratories (China); Wu Hong [Fourth Military Medical University, Department of Pharmacy (China); Teng Zenghui [Fourth Military Medical University, Department of Pharmacology (China); Guo Guozhen, E-mail: guozhengg@tom.co [Fourth Military Medical University, Department of Radiation Medicine (China); Chen Jingyuan, E-mail: jy_chen@fmmu.edu.c [Fourth Military Medical University, Department of Occupational and Environmental Health (China)

    2008-08-15

    SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

  19. Nafcillin-loaded PLGA nanoparticles for treatment of osteomyelitis

    International Nuclear Information System (INIS)

    Pillai, Rajeev Raghavan; Rabinovich, Monica; Gonsalves, Kenneth E; Somayaji, Shankari N; Hudson, Michael C

    2008-01-01

    The goal of this investigation is to develop poly(dl-lactide-co-glycolide) (PLGA) nanoparticles for the delivery of antibiotics such as nafcillin to osteoblasts. This is important in order to treat Staphylococcus aureus-mediated osteomyelitis. The latter is often chronic and highly resistant to antibiotics. Nafcillin (a penicillinase-resistant penicillin)-loaded nanoparticles were prepared by a single emulsion/solvent evaporation method. In vitro drug release studies were conducted in an incubator shaker at 37 deg. C in phosphate buffer saline. Drug loading and release were determined by UV-Vis spectroscopy. A viability study was conducted in S. aureus-infected mouse osteoblasts. In vitro release study showed an initial burst release and a second phase of slow release. Following 24 and 48 h of incubation, all formulations of nanoparticles loaded with nafcillin either killed or significantly reduced all of the intracellular bacteria. Our data demonstrate that effective killing of intracellular S. aureus is possible by treating the infected osteoblasts with nanoparticles loaded with nafcillin

  20. Nafcillin-loaded PLGA nanoparticles for treatment of osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Pillai, Rajeev Raghavan; Rabinovich, Monica; Gonsalves, Kenneth E [Polymer Nanotechnology Laboratory at Center for Optoelectronics and Department of Chemistry, University of North Carolina, Charlotte, NC 28223 (United States); Somayaji, Shankari N; Hudson, Michael C [Department of Biology, University of North Carolina, Charlotte, NC 28223 (United States)], E-mail: kegonsal@uncc.edu

    2008-09-01

    The goal of this investigation is to develop poly(dl-lactide-co-glycolide) (PLGA) nanoparticles for the delivery of antibiotics such as nafcillin to osteoblasts. This is important in order to treat Staphylococcus aureus-mediated osteomyelitis. The latter is often chronic and highly resistant to antibiotics. Nafcillin (a penicillinase-resistant penicillin)-loaded nanoparticles were prepared by a single emulsion/solvent evaporation method. In vitro drug release studies were conducted in an incubator shaker at 37 deg. C in phosphate buffer saline. Drug loading and release were determined by UV-Vis spectroscopy. A viability study was conducted in S. aureus-infected mouse osteoblasts. In vitro release study showed an initial burst release and a second phase of slow release. Following 24 and 48 h of incubation, all formulations of nanoparticles loaded with nafcillin either killed or significantly reduced all of the intracellular bacteria. Our data demonstrate that effective killing of intracellular S. aureus is possible by treating the infected osteoblasts with nanoparticles loaded with nafcillin.

  1. Periodontal regeneration using a bilayered PLGA/calcium phosphate construct.

    Science.gov (United States)

    Carlo Reis, Emily C; Borges, Andréa P B; Araújo, Michel V F; Mendes, Vanessa C; Guan, Limin; Davies, John E

    2011-12-01

    The regeneration of tissues affected by periodontal disease is a complex process; it encompasses the formation of bone, cementum and periodontal ligament. We developed a semi-rigid PLGA (polylactide-co-glycolide acid)/CaP (calcium phosphate) bilayered biomaterial construct to promote periodontal regeneration, which has a continuous outer barrier membrane and an inner topographically complex component. Our experimental model compared periodontal prophylaxis alone with prophylaxis and biomaterial implantation in the treatment of class II furcation defects in dogs. Clinical evaluation, micro-computed tomography, histology and backscattered electron imaging were used for data analysis. Healing occurred uneventfully and bone volumetric values, trabecular number and trabecular thickness were all significantly greater in the treated group; while trabecular separation was significantly greater in the control group. New cementum, bone, and periodontal ligament with Sharpey fibre insertions were only seen in the treated group. Although periodontal regeneration has been reported elsewhere, the advantages of employing our bilayered PLGA + CaP construct are twofold: 1)it did not collapse into the defect; and, 2) its inner side was able to retain the blood clot throughout the buccal defect. The result was greater periodontal regeneration than has previously been reported with traditional flexible membranes. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Cellular uptake and radiosensitization of SR-2508 loaded PLGA nanoparticles

    International Nuclear Information System (INIS)

    Jin Cheng; Bai Ling; Wu Hong; Teng Zenghui; Guo Guozhen; Chen Jingyuan

    2008-01-01

    SR-2508 (etanidazole), a hypoxic radiosensitizer, has potential applications in radiotherapy. The poly(d,l-lactide-co-glycolide)(PLGA) nanoparticles containing SR-2508 were prepared by w/o/w emulsification-solvent evaporation method. The physicochemical characteristics of the nanoparticles (i.e. encapsulation efficiency, particle size distribution, morphology, in vitro release) were studied. The cellular uptake of the nanoparticles for the two human tumor cell lines: human breast carcinoma cells (MCF-7) and human carcinoma cervices cells (HeLa), was evaluated by fluorescence microscopy and transmission electronic microscopy. Cell viability was measured by the ability of single cell to form colonies in vitro. The prepared nanoparticles were spherical in shape with size between 90 nm and 190 nm. The encapsulation efficiency was 20.06%. The drug release pattern exhibited an initial burst followed by a plateau for over 24 h. The cellular uptake of nanoparticles was observed. Co-culture of MCF-7 and HeLa cells with SR-2508 loaded nanoparticles showed that released SR-2508 retained its bioactivity and effectively sensitized two hypoxic tumor cell lines to radiation. The radiosensitization of SR-2508 loaded nanoparticles was more significant than that of free drug.

  3. Optimization of sustained release aceclofenac microspheres using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Deshmukh, Rameshwar K.; Naik, Jitendra B., E-mail: jitunaik@gmail.com

    2015-03-01

    Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14 ± 0.015% to 85.34 ± 0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12 h. The optimized microspheres formulation showed E.E. of 84.87 ± 0.005 with small error value (1.39). The low magnitudes of error and the significant value of R{sup 2} in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects. - Highlights: • Aceclofenac microspheres

  4. Which are risk factors developing renal cortical defects on {sup 99m}Tc-DMSA scintigraphy in children with acute urinary tract infections?

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Seong Won; Lim, Gye Yeon; Jang, Hae Suk; Lee, Eun Ja; Sohn, Hyung Sun; Hahn, Sung Tae [The Catholic University, Seoul (Korea, Republic of)

    2000-04-01

    To determine (1) the relationship between the cortical defects seen on {sup 99}''mTc-DMSA renal scans and age, and (2) the presence and degree of vesicoureteral reflux, and then to depict the risk factors for cortical defects in children with acute urinary tract infection (UTI). Furthermore, to assess the diagnostic value of VCUG in predicting a defect on {sup 99m}Tc-DMSA renal scans. We studied 134 kidneys in 67 children aged 15 days-10 years (M:F =3D 39:28) in whom symptomatic UTI was present. In all these children, both DMSA renal scans and voiding cystourethrography (VCUG) were performed. Scanning took place within 7 days of diagnosis and VCUG was performed after one month of diagnosis. Scintigraphic findings were graded according to the extent and number of cortical defects. We evaluated the relationships between the cortical defects seen on DMSA scans and age, and the grade of vesicoureteral reflux. The diagnostic value of VCUG in predicting cortical defects was analysed. The prevalence of cortical defects was greater in patients older than two years (38/54, 70%) than in those aged less than two (38/80, 48%). The frequency of cortical defects was related to vesicoureteral reflux (p less than 0.05) and grade of reflux (p less than 0.05). As this latter increased, the extent of cortical defects also increased (p less than 0.05), and DMSA scans revealed the presence of these in 76 of the 134 kidneys (57%) with acute UTI. In 30 of these 76 (39.5%), VCUG demonstrated the presence of vesicoureteral reflex. On the other hand, vesicoureteral reflex was found in 36 of the 134 kidneys (27%), and in 30 of these 36 (83%), cortical defects were noted. The sensitivity of VCUG in predicting cortical defect was 39.5%, while specificity was 89.7%. The positive predictive value for defects was 83.3%, and the negative predictive value was 53.1%. The relative risk of cortical defect in the presence of vesicoureteral reflux was 1.78. Renal cortical defects are

  5. Interest of 99mTc-DMSA in the exploration of non-functional kidneys in the intravenous urography; report of 20 cases

    International Nuclear Information System (INIS)

    Ghfir, I.; Ouboukdir, R.; Ben Rais, N.

    2008-01-01

    Introduction The renal scintigraphy using 99m Tc-DMSA constitutes a non-invasive and functional method that is of appreciable interest in the qualitative study of renal parenchyma and the evaluation of the separate renal function. Material and methods We report, through this work, the observation of 20 patients presenting a unilateral renal muteness to the intravenous urography (I.V.U.). A 99m Tc-DMSA scintigraphy was carried out among all our patients by means of a gamma-camera with large field equipped with a parallel collimator of weak energy and high-resolution. The evaluation of images obtained consisted of a qualitative study of parenchyma as well as an estimate of the functional value separated from the two kidneys obtained by the calculation of geometric mean. Results On the 20 studied cases, the sex-ratio was equal to 1.16; the average age was 29.72 years with extremes spanning from 18 months to 70 years. The renal muteness reported on intravenous urography was due among 12 patients (60% of cases) to a lithiasis origin, in six patients (30% of cases), to an ureteral-pelvic junction, in one patient (5% of cases), to a chronic pyelonephritis and in another patient (5% of cases) to a mega urethra. The separated renal function of the non functional kidneys to the I.V.U., obtained from the renal 99m Tc-DMSA scintigraphy varied from 11% to 31% with an average of 20.6%. Discussion Through our series, 99m Tc-DMSA scintigraphy allowed to alleviate the limits of I.V.U. in the evaluation of the precise functional value of pathologic kidneys. Indeed, in the 20 studied cases where the I.V.U. had reported a renal muteness, the 99m Tc-DMSA scintigraphy allowed a better appreciation of the renal function which varied from 11% to 31% thus calling into question the accuracy of I.V.U. in the exploration of renal function at an advanced stage of uropathy. (N.C.)

  6. Which are risk factors developing renal cortical defects on 99mTc-DMSA scintigraphy in children with acute urinary tract infections?

    International Nuclear Information System (INIS)

    Moon, Seong Won; Lim, Gye Yeon; Jang, Hae Suk; Lee, Eun Ja; Sohn, Hyung Sun; Hahn, Sung Tae

    2000-01-01

    To determine (1) the relationship between the cortical defects seen on 99 ''mTc-DMSA renal scans and age, and (2) the presence and degree of vesicoureteral reflux, and then to depict the risk factors for cortical defects in children with acute urinary tract infection (UTI). Furthermore, to assess the diagnostic value of VCUG in predicting a defect on 99m Tc-DMSA renal scans. We studied 134 kidneys in 67 children aged 15 days-10 years (M:F =3D 39:28) in whom symptomatic UTI was present. In all these children, both DMSA renal scans and voiding cystourethrography (VCUG) were performed. Scanning took place within 7 days of diagnosis and VCUG was performed after one month of diagnosis. Scintigraphic findings were graded according to the extent and number of cortical defects. We evaluated the relationships between the cortical defects seen on DMSA scans and age, and the grade of vesicoureteral reflux. The diagnostic value of VCUG in predicting cortical defects was analysed. The prevalence of cortical defects was greater in patients older than two years (38/54, 70%) than in those aged less than two (38/80, 48%). The frequency of cortical defects was related to vesicoureteral reflux (p less than 0.05) and grade of reflux (p less than 0.05). As this latter increased, the extent of cortical defects also increased (p less than 0.05), and DMSA scans revealed the presence of these in 76 of the 134 kidneys (57%) with acute UTI. In 30 of these 76 (39.5%), VCUG demonstrated the presence of vesicoureteral reflex. On the other hand, vesicoureteral reflex was found in 36 of the 134 kidneys (27%), and in 30 of these 36 (83%), cortical defects were noted. The sensitivity of VCUG in predicting cortical defect was 39.5%, while specificity was 89.7%. The positive predictive value for defects was 83.3%, and the negative predictive value was 53.1%. The relative risk of cortical defect in the presence of vesicoureteral reflux was 1.78. Renal cortical defects are significantly related to age

  7. Preparation and Characterization of Fluorescent SiO2 Microspheres

    Science.gov (United States)

    Xu, Cui; Zhang, Hao; Guan, Ruifang

    2018-01-01

    Fluorescent compound without typical fluorophores was synthesized with citric acid (CA) and aminopropyltriethoxysilane (APTS) firstly, and then it was grafted to the surface of the prepared SiO2 microspheres by chemical reaction. The fluorescent SiO2 microspheres with good fluorescent properties were obtained by optimizing the reaction conditions. And the morphology and structure of the fluorescent SiO2 microspheres have been characterized by scanning electron microscopy (SEM) and fourier transform infrared (FTIR) spectroscopy. The results showed that the preparation of fluorescent SiO2 microspheres have good monodispersity and narrow particle size distribution. Moreover, the fluorescent SiO2 microspheres can be applied to detect Fe3+ in aqueous solution, prepare fluorescent SiO2 rubber, and have potential to be applied in the fluorescent labeling and fingerprint appearing technique fields.

  8. Study on the Degradation of Polylactide Microsphere In Vitro

    Institute of Scientific and Technical Information of China (English)

    HeYing; WeiShuli

    2001-01-01

    This report concentrated on the rules and mechanism of the degradation of polylactide and the microspheres. The rate of degradation was assessed with five methods: observation of microsphere surface morphology by SEM, determination of the weight loss of the microspheres, determination of the molecular mass of the polymers by GPC, determination of pH and determination of the contents of lactic acid by UV spectrophotometry. The degradation of polylactide microspheres showed two-phase characteristics. At the early stage of the degradation, the high molecular mass polymers were cleaved into lower molecular mass fractions and at the late stage, there was a period of erosion and weight loss of the microspheres. The degradation was much slower for polymers with a higher molecular mass. The polylactide degradation showed good regularity.

  9. Hollow porous-wall glass microspheres for hydrogen storage

    Science.gov (United States)

    Heung, Leung K.; Schumacher, Ray F.; Wicks, George G.

    2010-02-23

    A porous wall hollow glass microsphere is provided having a diameter range of between 1 to 200 microns, a density of between 1.0 to 2.0 gm/cc, a porous-wall structure having wall openings defining an average pore size of between 10 to 1000 angstroms, and which contains therein a hydrogen storage material. The porous-wall structure facilitates the introduction of a hydrogen storage material into the interior of the porous wall hollow glass microsphere. In this manner, the resulting hollow glass microsphere can provide a membrane for the selective transport of hydrogen through the porous walls of the microsphere, the small pore size preventing gaseous or liquid contaminants from entering the interior of the hollow glass microsphere.

  10. Bone induction by biomimetic PLGA copolymer loaded with a novel synthetic RADA16-P24 peptide in vivo

    International Nuclear Information System (INIS)

    Pan, Haitao; Hao, Shaofei; Zheng, Qixin; Li, Jingfeng; Zheng, Jin; Hu, Zhilei; Yang, Shuhua; Guo, Xiaodong; Yang, Qin

    2013-01-01

    Bone morphogenetic protein-2 (BMP-2) is a key bone morphogenetic protein, and poly(lactic-co-glycolic acid) (PLGA) has been widely used as scaffold for clinical use to carry treatment protein. In the previous studies, we have synthesized BMP-2-related peptide (P24) and found its capacity of inducing bone regeneration. In this research, we have synthesized a new amphiphilic peptide Ac-RADA RADA RADA RADA S[PO4]KIPKASSVPTELSAISTLYLDDD-CONH2 (RADA16-P24) with an assembly peptide RADA16-Ion the P24 item of BMP2 to form divalent ion-induced gelatin. Two methods of physisorption and chemical cross-linking were used to bind RADA16-P24 onto the surface of the copolymer PLGA to synthesize RADA16-P24–PLGA, and its capacity of attaching bone marrow stromal cells (BMSCs) was evaluated in vitro and inducing ectopic bone formation was examined in vivo. In vitro our results demonstrated that RADA16-P24–PLGA copolymer prepared by physisorbing or prepared by chemical cross-linking had a peptide binding rate of (2.0180 ± 0.5296)% or (10.0820 ± 0.8405)% respectively (P < 0.05). In addition the BMSCs proliferated vigorously in the RADA16-P24–PLGA biomaterials. Significantly the percentage of BMSCs attached to RADA16-P24–PLGA composite prepared by chemical cross-linking and physisorbing were (71.4 ± 7.5) % or (46.7 ± 5.8) % (P < 0.05). The in vivo study showed that RADA16-P24–PLGA chemical cross-linking could better induce ectopic bone formation compared with RADA16-P24–PLGA physisorbing and PLGA. It is concluded that the PLGA copolymer is a good RADA16-P24 carrier. This novel RADA16-P24–PLGA composite has strong osteogenic capability. - Highlights: • We have synthesized a new RADA16-P24 amphiphilic peptide. • It is an assembly peptide RADA16-Ion the P24 to form divalent ion-induced gelatin. • RADA16-P24/PLGA could better induce etopia osteogenesis compared with PLGA. • RADA16-P24–PLGA has strong osteogenic capability

  11. Bone induction by biomimetic PLGA copolymer loaded with a novel synthetic RADA16-P24 peptide in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Haitao; Hao, Shaofei [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Zheng, Qixin, E-mail: zheng-qx@163.com [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Li, Jingfeng [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Department of Orthopedics, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Zheng, Jin; Hu, Zhilei; Yang, Shuhua; Guo, Xiaodong [Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022 (China); Yang, Qin [Advanced Biomaterials and Tissue Engineering Center, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-08-01

    Bone morphogenetic protein-2 (BMP-2) is a key bone morphogenetic protein, and poly(lactic-co-glycolic acid) (PLGA) has been widely used as scaffold for clinical use to carry treatment protein. In the previous studies, we have synthesized BMP-2-related peptide (P24) and found its capacity of inducing bone regeneration. In this research, we have synthesized a new amphiphilic peptide Ac-RADA RADA RADA RADA S[PO4]KIPKASSVPTELSAISTLYLDDD-CONH2 (RADA16-P24) with an assembly peptide RADA16-Ion the P24 item of BMP2 to form divalent ion-induced gelatin. Two methods of physisorption and chemical cross-linking were used to bind RADA16-P24 onto the surface of the copolymer PLGA to synthesize RADA16-P24–PLGA, and its capacity of attaching bone marrow stromal cells (BMSCs) was evaluated in vitro and inducing ectopic bone formation was examined in vivo. In vitro our results demonstrated that RADA16-P24–PLGA copolymer prepared by physisorbing or prepared by chemical cross-linking had a peptide binding rate of (2.0180 ± 0.5296)% or (10.0820 ± 0.8405)% respectively (P < 0.05). In addition the BMSCs proliferated vigorously in the RADA16-P24–PLGA biomaterials. Significantly the percentage of BMSCs attached to RADA16-P24–PLGA composite prepared by chemical cross-linking and physisorbing were (71.4 ± 7.5) % or (46.7 ± 5.8) % (P < 0.05). The in vivo study showed that RADA16-P24–PLGA chemical cross-linking could better induce ectopic bone formation compared with RADA16-P24–PLGA physisorbing and PLGA. It is concluded that the PLGA copolymer is a good RADA16-P24 carrier. This novel RADA16-P24–PLGA composite has strong osteogenic capability. - Highlights: • We have synthesized a new RADA16-P24 amphiphilic peptide. • It is an assembly peptide RADA16-Ion the P24 to form divalent ion-induced gelatin. • RADA16-P24/PLGA could better induce etopia osteogenesis compared with PLGA. • RADA16-P24–PLGA has strong osteogenic capability.

  12. Treating cutaneous squamous cell carcinoma using ALA PLGA nanoparticle-mediated photodynamic therapy in a mouse model

    Science.gov (United States)

    Wang, Xiaojie; Shi, Lei; Tu, Qingfeng; Wang, Hongwei; Zhang, Haiyan; Wang, Peiru; Zhang, Linglin; Huang, Zheng; Wang, Xiuli; Zhao, Feng; Luan, Hansen

    2015-03-01

    Background: Squamous cell carcinoma (SCC) is a common skin cancer and its treatment is still difficult. The aim of this study was to evaluate the effectiveness of nanoparticle (NP)-assisted ALA delivery for topical photodynamic therapy (PDT) of cutaneous SCC. Methods: UV-induced cutaneous SCCs were established in hairless mice. ALA loaded polylactic-co-glycolic acid (PLGA) NPs were prepared and characterized. The kinetics of ALA PLGA NPs-induced protoporphyrin IX (PpIX) fluorescence in SCCs, therapeutic efficacy of ALA NP-mediated PDT, and immune responses were examined. Results: PLGA NPs could enhance PpIX production in SCC. ALA PLGA NP mediated topical PDT was more effective than free ALA of the same concentration in treating cutaneous SCC. Conclusion: PLGA NPs provide a promising strategy for delivering ALA in topical PDT of cutaneous SCC.

  13. DMSA-scintigraphy in paediatrics: is the evaluation of the geometric mean necessary for the calculation of the differential renal function?; Partialfunktionsberechnung der Nieren mit DMSA in der Paediatrie: ist fuer die Bestimmung das geometrische Mittel notwendig?

    Energy Technology Data Exchange (ETDEWEB)

    Porn, U.; Alalp, S.; Fischer, S.; Dresel, S. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Rossmueller, B. [Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Hahn, K. [Klinik und Poliklinik fuer Nuklearmedizin, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany); Inst. fuer Radiologische Diagnostik, Klinikum der Ludwig-Maximilians-Univ. Muenchen (Germany)

    2001-08-01

    For assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimercaptosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. Aim of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. Methods: 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 {+-} 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256, 300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Cts{sub dors} x Cts{sub ventr})]. Results: The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p<0.01). The mean difference between the PF{sub geom} and the PF{sub dors} was 1.5 {+-} 1.4%. A difference {>=}5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PF{sub dors} due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference >5% did not show any renal abnormality. Conclusion: The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differential renal function in orthotopic kidneys, so that in these cases the anterior view is not necessary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in

  14. PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα

    Science.gov (United States)

    Hu, Xiaoyu; Huang, Fang; Szymusiak, Magdalena; Tian, Xuebi; Liu, Ying; Wang, Zaijie Jim

    2016-01-01

    Opioid-induced hyperalgesia (OIH) is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin) in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin’s mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling. PMID:26744842

  15. PLGA-Curcumin Attenuates Opioid-Induced Hyperalgesia and Inhibits Spinal CaMKIIα.

    Directory of Open Access Journals (Sweden)

    Xiaoyu Hu

    Full Text Available Opioid-induced hyperalgesia (OIH is one of the major problems associated with prolonged use of opioids for the treatment of chronic pain. Effective treatment for OIH is lacking. In this study, we examined the efficacy and preliminary mechanism of curcumin in attenuating OIH. We employed a newly developed PLGA-curcumin nanoformulation (PLGA-curcumin in order to improve the solubility of curcumin, which has been a major obstacle in properly characterizing curcumin's mechanism of action and efficacy. We found that curcumin administered intrathecally or orally significantly attenuated hyperalgesia in mice with morphine-induced OIH. Furthermore, we demonstrated that the effects of curcumin on OIH correlated with the suppression of chronic morphine-induced CaMKIIα activation in the superficial laminae of the spinal dorsal horn. These data suggest that PLGA-curcumin may reverse OIH possibly by inhibiting CaMKIIα and its downstream signaling.

  16. Synthesis and characterization of PLGA nanoparticles containing mixture of curcuminoids for optimization of photodynamic inactivation

    Science.gov (United States)

    Suzuki, Isabella L.; Inada, Natália M.; Marangoni, Valéria S.; Corrêa, Thaila Q.; Zucolotto, Valtencir; Kurachi, Cristina; Bagnato, Vanderlei S.

    2016-03-01

    Because of excessive use of antibiotics there is a growth in the number of resistant strains. Due to this growth of multiresistant bacteria, the number of searches looking for alternatives antibacterial therapeutic has increased, and among them is the antimicrobial photodynamic therapy (aPDT) or photodynamic inactivation (PDI). The photodynamic inactivation involves the action of a photosensitizer (PS), activated by a specific wavelength, in the present of oxygen, resulting in cytotoxic effect. Natural curcumin, consists of a mixture of three curcuminoids: curcumin, demethoxycurcumin and bis-demethoxycurcumin. Curcumin has various pharmacological properties, however, has extremely low solubility in aqueous solutions, which difficult the use as therapeutic agent. The present study aims to develop polymeric PLGA nanoparticles containing curcuminoids to improve water solubility, increase bioavailability providing protection from degradation (chemistry and physics), and to verify the efficacy in photodynamic inactivation of microorganisms. The PLGA-CURC were synthesized by nanoprecipitation, resulting in two different systems, with an average size of 172 nm and 70% encapsulation efficiency for PLGA-CURC1, and 215 nm and 80% for PLGA-CURC2. Stability tests showed the polymer protected the curcuminoids against premature degradation. Microbiological tests in vitro with curcuminoids water solution and both suspension of PLGA-CURC were efficient in Gram-positive bacterium and fungus. However, the solution presented dark toxicity at high concentrations, unlike the nanoparticles. Thus, it was concluded that it was possible to let curcuminoids water soluble by encapsulation in PLGA nanoparticles, to ensure improved stability in aqueous medium (storage), and to inactivate bacteria and fungus.

  17. Biodegradable PLGA-b-PEG polymeric nanoparticles: synthesis, properties, and nanomedical applications as drug delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Locatelli, Erica; Comes Franchini, Mauro, E-mail: mauro.comesfranchini@unibo.it [University of Bologna, Dipartimento di Chimica Industriale Toso Montanari (Italy)

    2012-12-15

    During the past decades many synthetic polymers have been studied for nanomedicine applications and in particular as drug delivery systems. For this purpose, polymers must be non-toxic, biodegradable, and biocompatible. Polylactic-co-glycolic acid (PLGA) is one of the most studied polymers due to its complete biodegradability and ability to self-assemble into nanometric micelles that are able to entrap small molecules like drugs and to release them into body in a time-dependent manner. Despite fine qualities, using PLGA polymeric nanoparticles for in vivo applications still remains an open challenge due to many factors such as poor stability in water, big diameter (150-200 nm), and the removal of these nanocarriers from the blood stream by the liver and spleen thus reducing the concentration of drugs drastically in tumor tissue. Polyethylene glycol (PEG) is the most used polymers for drug delivery applications and the first PEGylated product is already on the market for over 20 years. This is due to its stealth behavior that inhibits the fast recognition by the immune system (opsonization) and generally leads to a reduced blood clearance of nanocarriers increasing blood circulation time. Furthermore, PEG is hydrophilic and able to stabilize nanoparticles by steric and not ionic effects especially in water. PLGA-PEG block copolymer is an emergent system because it can be easily synthesized and it possesses all good qualities of PLGA and also PEG capability so in the last decade it arose as one of the most promising systems for nanoparticles formation, drug loading, and in vivo drug delivery applications. This review will discuss briefly on PLGA-b-PEG synthesis and physicochemical properties, together with its improved qualities with respect to the single PLGA and PEG polymers. Moreover, we will focus on but in particular will treat nanoparticles formation and uses as new drug delivery system for nanomedical applications.

  18. Electrospraying technique for the fabrication of metronidazole contained PLGA particles and their release profile

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Molamma P., E-mail: nnimpp@nus.edu.sg [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Zamani, Maedeh [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Felice, Betiana [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Laboratorio de Medios e Interfases, Departamento de Bioingeniería, Universidad Nacional de Tucumán, Av. Independencia 1800, Tucumán (Argentina); Ramakrishna, Seeram [Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore)

    2015-11-01

    Advanced engineering of materials for the development of drug delivery devices provides scope for novel and versatile strategies for treatment of various diseases. ‘Electrospraying’ was used to prepare PLGA microparticles and further encapsulate the drug, metronidazole (Met) within the particles to function as a drug delivery system. Two different solvents were utilized for the preparation of drug loaded PLGA particles, whereby the polymeric solution in dichloromethane (DCM) produced particles of bigger sizes than using trifluoroethanol (TFE). Scanning electron microscopy showed the spherical morphology of the particles, with sizes of 3946 ± 407 nm and 1774 ± 167 nm, respectively for PLGA-Met(DCM) and PLGA-Met(TFE). The FTIR spectroscopy proved the incorporation of metronidazole in the polymer, but without any specific drug–polymer interaction. The release of the drug from the particles was studied in phosphate buffered saline, where a sustained drug release was obtained for at least 41 days. Cytotoxicity evaluation of the drug extract using mesenchymal stem cells (MSCs) showed not hindering the proliferation of MSCs, and the cell phenotype was retained after incubation in the drug containing media. Electrospraying is suggested as a cost-effective and single step process for the preparation of polymeric microparticles for prolonged and controlled release of drug. - Highlights: • Electrospraying as a novel method for the fabrication of drug delivery device • Metronidazole encapsulated PLGA particles were fabricated by electrospraying. • Solvent DCM produced particles of double the size than using TFE. • Sustained release of metronidazole studied for a period of 41 days • Drug release pattern from particles followed Fickian diffusion. • PLGA-metronidazole particles can function as a substrate for periodontal regeneration.

  19. Aptamer conjugated paclitaxel and magnetic fluid loaded fluorescently tagged PLGA nanoparticles for targeted cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Aravind, Athulya; Nair, Remya; Raveendran, Sreejith; Veeranarayanan, Srivani; Nagaoka, Yutaka; Fukuda, Takahiro; Hasumura, Takahashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D., E-mail: sakthi@toyo.jp

    2013-10-15

    Controlled and targeted drug delivery is an essential criterion in cancer therapy to reduce the side effects caused by non-specific drug release and toxicity. Targeted chemotherapy, sustained drug release and optical imaging have been achieved using a multifunctional nanocarrier constructed from poly (D, L-lactide-co-glycolide) nanoparticles (PLGA NPs), an anticancer drug paclitaxel (PTX), a fluorescent dye Nile red (NR), magnetic fluid (MF) and aptamers (Apt, AS1411, anti-nucleolin aptamer). The magnetic fluid and paclitaxel loaded fluorescently labeled PLGA NPs (MF-PTX-NR-PLGA NPs) were synthesized by a single-emulsion technique/solvent evaporation method using a chemical cross linker bis (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles. Targeting aptamers were then introduced to the particles through the reaction with the cross linker to target the nucleolin receptors over expressed on the cancer cell surface. Specific binding and uptake of the aptamer conjugated magnetic fluid loaded fluorescently tagged PLGA NPs (Apt-MF-NR-PLGA NPs) to the target cancer cells induced by aptamers was observed using confocal microscopy. Cytotoxicity assay conducted in two cell lines (L929 and MCF-7) confirmed that targeted MCF-7 cancer cells were killed while control cells were unharmed. In addition, aptamer mediated delivery resulting in enhanced binding and uptake to the target cancer cells exhibited increased therapeutic effect of the drug. Moreover, these aptamer conjugated magnetic polymer vehicles apart from actively transporting drugs into specifically targeted tumor regions can also be used to induce hyperthermia or for facilitating magnetic guiding of particles to the tumor regions. - Highlights: • Aptamer escorted, theranostic biodegradable PLGA carriers were developed. • Can target cancer cells, control drug release, image and magnetically guide. • Highly specific to the targeted cancer cells thus delivering

  20. Mesoporous metal oxide microsphere electrode compositions and their methods of making

    Science.gov (United States)

    Parans Paranthaman, Mariappan; Bi, Zhonghe; Bridges, Craig A.; Brown, Gilbert M.

    2017-04-11

    Compositions and methods of making are provided for treated mesoporous metal oxide microspheres electrodes. The compositions include microspheres with an average diameter between about 200 nanometers and about 10 micrometers and mesopores on the surface and interior of the microspheres. The methods of making include forming a mesoporous metal oxide microsphere composition and treating the mesoporous metal oxide microspheres by at least annealing in a reducing atmosphere, doping with an aliovalent element, and coating with a coating composition.

  1. Long pulse microsphere experiments at 3 TW

    International Nuclear Information System (INIS)

    Boyle, M.J.; Attwood, D.T.; Brooks, K.M.

    1977-01-01

    Previous 1.06 μm laser implosion experiments have explored the parameter space associated with microsphere targets of typically less than 100 psec. Exploding pusher experiments have now been performed using long pulses (100 to 200 psec FWHM), and large diameter (100 to 150 μm) targets on the 3 TW Argus laser facility. Absorption, transport, implosion and neutron and α yield characteristics are discussed and compared with earlier short pulse results. The observed neutron yields are discussed in light of the temporal mismatch between the absorption and implosion time scales imposed by the large diameter, long pulse conditions

  2. Silver ion beam irradiation effects on poly(lactide-co-glycolide) (PLGA)/clay nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Manpreet; Singh, Surinder [Guru Nanak Dev University, Department of Physics, Amritsar (India); Mehta, Rajeev [Thapar University, Department of Chemical Engineering, Patiala (India)

    2014-12-15

    Swift heavy ions induced modification of thin films of blends of poly(lactide-co-glycolide) (PLGA) (50:50) with organically modified nanoclay (Cloisite {sup registered} 30B) has been studied, using optical, structural and surface morphological analysis. Presence of nanoclay is found to enhance the properties of this degradable copolymer by reducing the rate of degradation even at high irradiation fluence. Optical and structural analysis of the polymer nanocomposites suggests that both the cross-linking and chain scission phenomenon are caused by swift heavy ion irradiation. XRD measurements show intercalation of PLGA in the clay galleries. Surface morphology of a nanocomposite indicates significant changes after irradiation at various fluences. (orig.)

  3. Biotin decorated PLGA nanoparticles containing SN-38 designed for cancer therapy.

    Science.gov (United States)

    Mehdizadeh, Mozhdeh; Rouhani, Hasti; Sepehri, Nima; Varshochian, Reyhaneh; Ghahremani, Mohammad Hossein; Amini, Mohsen; Gharghabi, Mehdi; Ostad, Seyed Nasser; Atyabi, Fatemeh; Baharian, Azin; Dinarvand, Rassoul

    2017-05-01

    Active targeted chemotherapy is expected to provide more specific delivery of cytotoxic drugs to the tumor cells and hence reducing the side effects on healthy tissues. Due to the over expression of biotin receptors on cancerous cells as a result of further requirement for rapid proliferations, biotin can be a good candidate as a targeting agent. In this study, biotin decorated PLGA nanoparticles (NPs) containing SN-38 were prepared and in vitro studies were evaluated for their improved anti-cancer properties. In conclusion, biotin targeted PLGA NPs containing SN-38 showed preferential anticancer properties against tumor cells with biotin receptor over expression.

  4. DMSA scan nomograms for renal length and area: Related to patient age and to body weight, height or surface area

    International Nuclear Information System (INIS)

    Hassan, I.M.; Que, L.; Rutland, M.D.

    2002-01-01

    Aim: To create nomograms for renal size as measured from DMSA renal studies, and to test the nomograms for their ability to separate normal from abnormal kidneys. Method: Renal length was measured from posterior oblique views and renal area from posterior views. Results from 253 patients with bilateral normal kidneys were used to create nomograms for renal size relative to patient age, body height, weight or body surface area (BSA). The nomograms enclosed 95% of the normal kidneys, thus indicating the range for 95% confidence limits, and hence the specificity. Each nomogram was then tested against 46 hypertrophied kidneys and 46 damaged kidneys. Results: The results from nomograms of renal length and renal area, compared to age, body height, body weight and BSA are presented. For each nomogram, the range is presented as a fraction of the mean value, and the number of abnormal kidneys (hypertrophied or damaged) outside the normal range is presented as a percentage (indicating the sensitivity). Conclusion: Renal Area was no better than renal length for detecting abnormal kidneys. Patient age was the least useful method of normalisation. BSA normalisation produced the best results most frequently (narrower ranges and highest detection of abnormal kidneys)

  5. Effect of n-HA with different surface-modified on the properties of n-HA/PLGA composite

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Liuyun, E-mail: jlytxg@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Xiong Chengdong; Chen Dongliang [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Jiang Lixin [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Graduated School of Chinese Academy of Sciences, Beijing 100039 (China); Pang Xiubing [Zhejiang Apeloa Medical Technology Co. Ltd, Jinhua 322118 (China)

    2012-10-15

    Graphical abstract: The bend strength of n-HA/PLGA composite with the unmodified n-HA becomes lower than that of PLGA. However, when n-HA was modified by different methods, the bend strength of g-n-HA/PLGA composites gets a little increase than PLGA, and the g3-n-HA/PLGA shows the highest bend strength at 3% g3-n-HA loading amount in weight, reached 162 MPa, which was 24.4% higher than that of pure PLGA. Highlights: Black-Right-Pointing-Pointer A new surface modification method for n-HA of combining stearic acid with surface-grafting L-lactic was adopted. Black-Right-Pointing-Pointer Three different surface modification methods for n-HA were compared in detail. Black-Right-Pointing-Pointer The new surface modification method was the most ideal method in this study. Black-Right-Pointing-Pointer The g3-n-HA/PLGA composite had the highest bending strength, which would be potential to be used as bone fracture internal fixation materials. - Abstract: Three different surface modification methods for nano-hydroxyapatite (n-HA) of stearic acid, grafted with L-lactide, combining stearic acid and surface-grafting L-lactic were adopted, respectively. The surface modification reaction and the effect of different methods were evaluated by Fourier transformation infrared (FTIR), X-ray photoelectron spectra (XPS), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM). The results showed that n-HA surfaces were all successful modified, and the modification method of combining stearic acid and surface-grafting L-lactic had the greatest grafting amount and the best dispersion among the three modification methods. Then, the n-HA with three different surface modification and unmodified n-HA were introduced into PLGA, respectively, and a serials of n-HA/PLGA composites with 3% n-HA amount in weight were prepared by solution mixing, and the properties of n-HA/PLGA composites were also investigated by electromechanical universal tester and scanning electron

  6. Structural and degradation characteristics of an innovative porous PLGA/TCP scaffold incorporated with bioactive molecular icaritin

    Energy Technology Data Exchange (ETDEWEB)

    Xie Xinhui; Wang Xinluan; Zhang Ge; He Yixin; Liu Zhong; Peng Jiang; Qin Ling [Department of Orthopaedics and Traumatology, Chinese University of Hong Kong (Hong Kong); Wang Xiaohong; He Kai [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education and Center of Organ Manufacturing, Department of Mechanical Engineering, Tsinghua University, Beijing (China); Leng Yang, E-mail: lingqin@cuhk.edu.h [Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2010-10-01

    Phytomolecules may chemically bind to scaffold materials for medical applications. The present study used an osteoconductive porous poly(l-lactide-co-glycolide)/tricalcium phosphate (PLGA/TCP) to incorporate an exogenous phytoestrogenic molecule icaritin to form a PLGA/TCP/icaritin composite scaffold material with potential slow release of icaritin during scaffold degradation. Accordingly, the present study was designed to investigate its in vitro degradation characteristics and the release pattern of icaritin at three different doses (74 mg, 7.4 mg and 0.74 mg per 100 g PLGA/TCP, i.e. in the PLGA/TCP/icaritin-H, -M and -L groups, respectively). A PLGA/TCP/icaritin porous composite scaffold was fabricated using a computer-controlled printing machine. The PLGA/TCP/icaritin scaffolds were incubated in saline at 37 {sup 0}C for 12 weeks and the pure PLGA/TCP scaffold served as a control. During the 12 weeks in vitro degradation, the scaffolds in all four groups showed changes, including a decrease in weight, volume and pore size of the composite scaffold, while there was a decrease in acidity and an increase in Ca and lactic acid concentrations in the degradation medium, especially after 7 weeks. The rate of degradation was explained by the relationship with the content of icaritin incorporated into the scaffolds. The higher the icaritin content in the scaffolds, the slower the degradation could be observed during 12 weeks. After 12 weeks, the SEM showed that the surface of the PLGA/TCP and PLGA/TCP/icaritin-L groups was relatively smooth with a gradual decrease in number and size of the micropores, while the porous morphology on the surface of the PLGA/TCP/icaritin-M and PLGA/TCP/icaritin-H groups was partly maintained, accompanied by a decrease in phosphate (P) and calcium (Ca) contents at the surface. Though the mechanical property of the PLGA/TCP/icaritin scaffold decreased after degradation, its porous structure was maintained, which was essential for cell

  7. Insulin delivery through nasal route using thiolated microspheres.

    Science.gov (United States)

    Nema, Tarang; Jain, Ashish; Jain, Aviral; Shilpi, Satish; Gulbake, Arvind; Hurkat, Pooja; Jain, Sanjay K

    2013-01-01

    The aim of the present study was to investigate the potential of developed thiolated microspheres for insulin delivery through nasal route. In the present study, cysteine was immobilized on carbopol using EDAC. A total of 269.93 µmol free thiol groups per gram polymer were determined. The prepared nonthiolated and thiolated microspheres were studied for particle shape, size, drug content, swellability, mucoadhesion and in vitro insulin release. The thiolated microspheres exhibited higher mucoadhesion due to formation of covalent bonds via disulfide bridges with the mucus gel layer. Drug permeation through goat nasal mucosa of nonthiolated and thiolated microspheres were found as 52.62 ± 2.4% and 78.85 ± 3.1% in 6 h, respectively. Thiolated microspheres bearing insulin showed better reduction in blood glucose level (BGL) in comparison to nonthiolated microspheres as 31.23 ± 2.12% and 75.25 ± 0.93% blood glucose of initial BGL were observed at 6 h after nasal delivery of thiolated and nonthiolated microspheres in streptozotocin-induced diabetic rabbits.

  8. Magnetic poly(glycidyl methacrylate) microspheres for protein capture.

    Science.gov (United States)

    Koubková, Jana; Müller, Petr; Hlídková, Helena; Plichta, Zdeněk; Proks, Vladimír; Vojtěšek, Bořivoj; Horák, Daniel

    2014-09-25

    The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Measurement of thermal diffusivity of depleted uranium metal microspheres

    Science.gov (United States)

    Humrickhouse-Helmreich, Carissa J.; Corbin, Rob; McDeavitt, Sean M.

    2014-03-01

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time-temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

  10. Measurement of thermal diffusivity of depleted uranium metal microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Humrickhouse-Helmreich, Carissa J., E-mail: carissahelmreich@tamu.edu [Texas A and M University, Department of Nuclear Engineering, 337 Zachry Engineering Center, 3133 TAMU, College Station, TX 77843 (United States); Corbin, Rob, E-mail: rcorbin@terrapower.com [TerraPower, LLC, 330 120th Ave NE, Suite 100, Bellevue, WA 98005 (United States); McDeavitt, Sean M., E-mail: mcdeavitt@tamu.edu [Texas A and M University, Department of Nuclear Engineering, 337 Zachry Engineering Center, 3133 TAMU, College Station, TX 77843 (United States)

    2014-03-15

    The high void space of nuclear fuels composed of homogeneous uranium metal microspheres may allow them to achieve ultra-high burnup by accommodating fuel swelling and reducing fuel/cladding interactions; however, the relatively low thermal conductivity of microsphere nuclear fuels may limit their application. To support the development of microsphere nuclear fuels, an apparatus was designed in a glovebox and used to measure the apparent thermal diffusivity of a packed bed of depleted uranium (DU) microspheres with argon fill in the void spaces. The developed Crucible Heater Test Assembly (CHTA) recorded radial temperature changes due to an initial heat pulse from a central thin-diameter cartridge heater. Using thermocouple positions and time–temperature data, the apparent thermal diffusivity was calculated. The thermal conductivity of the DU microspheres was calculated based on the thermal diffusivity from the CHTA, known material densities and specific heat capacities, and an assumed 70% packing density based on prior measurements. Results indicate that DU metal microspheres have very low thermal conductivity, relative to solid uranium metal, and rapidly form an oxidation layer even in a low oxygen environment. At 500 °C, the thermal conductivity of the DU metal microsphere bed was 0.431 ± 0.0560 W/m-K compared to the literature value of approximately 32 W/m-K for solid uranium metal.

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