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Sample records for biodegradable antibiotic delivery

  1. Novel solvent-free fabrication of biodegradable poly-lactic-glycolic acid (PLGA) capsules for antibiotics and rhBMP-2 delivery.

    Science.gov (United States)

    Liu, Shih-Jung; Chi, Po-Sheng; Lin, Song-Su; Ueng, Steve Wen-Neng; Chan, Err-Cheng; Chen, Jan-Kan

    2007-02-01

    Osteomyelitis has been one of the most common causes of post-operative problems and complications despite the advances in surgical techniques and the availability of newly developed antibiotics. Local antibiotic and growth factor delivery devices for treatment of various surgical infections have been studied recently, especially in the case of orthopedic infections. The report was to develop novel solvent-free biodegradable capsules for antibiotics and growth factors delivery. To fabricate a biodegradable capsule, polylactide-polyglycolide copolymers were pre-mixed with vancomycin. The mixture was then compression molded and sintered to form a cylinder with a cover of 8 mm in diameter. After the addition of 1 and 10 microg recombinant bone morphogenetic protein (rhBMP-2) into the core, an ultrasonic welder was used to seal the capsules. An elution method was employed to characterize the in vitro release characteristics of the antibiotics and the rhBMP-2 over a 30-day period. The HPLC analysis and the bacterial inhibition test showed that biodegradable capsules released high concentrations and activity of vancomycin (well above the minimum inhibition concentration) in vitro for the period of time needed to treat bone infection; i.e. 4-6 weeks. In addition, the results of ELISA and ALP tests also suggested that the capsules released active rhBMP-2 for up to 30 days. By adopting this novel technique, we will be able to fabricate biodegradable capsules of various medicines for long-term drug deliveries. PMID:17008035

  2. Primary biodegradation of veterinary antibiotics in aerobic and anaerobic surface water simulation systems

    DEFF Research Database (Denmark)

    Ingerslev, Flemming; Toräng, Lars; Loke, M.-L.;

    2001-01-01

    The primary aerobic and anaerobic biodegradability at intermediate concentrations (50-5000 mug/l) of the antibiotics olaquindox (OLA), metronidazole (MET), tylosin (TYL) and oxytetracycline (OTC) was studied in a simple shake flask system simulating the conditions in surface waters. The purpose of...... substances. The biodegradation behaviour was influenced by neither the concentrations of antibiotics nor the time of the year and location for sampling of surface water. Addition of 1 g/l of sediment or 3 mg/l of activated sludge from wastewater treatment increased the biodegradation potential which is...... the study was to provide rate data for primary biodegradation in the scenario where antibiotics pollute surface waters as a result of run-off from arable land. The source of antibiotics may be application of manure as fertilizer or excreta of grazing animals. Assuming first-order degradation kinetics...

  3. Biodegradable thermosensitive polymers: synthesis, characterization and drug delivery applications

    NARCIS (Netherlands)

    Soga, Osamu

    2006-01-01

    The aim of the research described in this Thesis is to design polymeric micelles showing controlled instability due to "hydrophobic to hydrophilic" conversion of the core, and to demonstrate its utility as a drug delivery vehicle. For that purpose, a novel class of thermosensitive and biodegradable

  4. Biocompatible medical implant materials with binding sites for a biodegradable drug-delivery system

    Directory of Open Access Journals (Sweden)

    Al-Dubai H

    2011-10-01

    Full Text Available Haifa Al-Dubai1, Gisela Pittner1, Fritz Pittner1, Franz Gabor21Max F Perutz Laboratories, Department of Biochemistry, University of Vienna, Vienna, Austria; 2Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Vienna, AustriaAbstract: Feasibility studies have been carried out for development of a biocompatible coating of medical implant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading might be possible. These novel coatings, able to bind biodegradable nanoparticles, may serve in the long run as drug carriers to mediate local pharmacological activity. After biodegradation of the nanoparticles, the binding sites could be reloaded with fresh drug-delivering particles. As a suitable receptor system for the nanoparticles, antibodies are anchored. The design of the receptor is of great importance as any bio- or chemorecognitive interaction with other components circulating in the blood has to be avoided. Furthermore, the binding between receptor and the particles has to be strong enough to keep them tightly bound during their lifetime, but on the other hand allow reloading after final degradation of the particles. The nanoparticles suggested as a drug-delivery system for medical implants can be loaded with different pharmaceuticals such as antibiotics, growth factors, or immunosuppressives. This concept may enable the changing of medication, even after implantation of the medical device, if afforded by patients’ needs.Keywords: antibody immobilization, biocompatible coating, chitosan nanoparticles, drug targeting, medical device

  5. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    International Nuclear Information System (INIS)

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  6. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hurkat, Pooja; Jain, Aviral; Jain, Ashish; Shilpi, Satish; Gulbake, Arvind; Jain, Sanjay K., E-mail: drskjainin@yahoo.com [Dr. Hari Singh Gour Vishwavidyalaya, Pharmaceutics Research Projects Laboratory, Department of Pharmaceutical Sciences (India)

    2012-11-15

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  7. A novel solvent-free method for the manufacture of biodegradable antibiotic-capsules for a long-term drug release using compression sintering and ultrasonic welding techniques.

    Science.gov (United States)

    Liu, Shih-Jung; Tsai, Ying-E; Wen-Neng Ueng, Steve; Chan, Err-Cheng

    2005-08-01

    This report was to develop a novel solvent-free method for the manufacture of biodegradable capsules for a long-term drug delivery. To manufacture an antibiotic capsule, polylactide-polyglycolide copolymers were pre-mixed with vancomycin. The mixture was then injection compression molded to form a cylinder with a cover of 8mm in diameter. After the addition of gentamicin sulfate into the core, an ultrasonic welder was used to seal the capsule. An elution method and an high-performance liquid chromatography assay were employed to characterize the in vitro release rates of the antibiotics over a 30-day period. It was found that biodegradable capsules released high concentration of vancomycin and gentamicin (well above the minimum inhibition concentration) in vitro for the period of time needed to treat bone infection; i.e., 2-4 weeks. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The diameter of the sample inhibition zone ranged from 3 to 18 mm, which is equivalent to 16.7-100% of relative activity. By adopting this novel technique, we will be able to manufacture biodegradable capsules of various medicines for long-term drug delivery. PMID:15722136

  8. ANTIBIOTIC SUSCEPTIBILITY OF BIODEGRADING BACTERIAL ISOLATES FROM DAIRY EFFLUENT

    OpenAIRE

    2013-01-01

    The present study investigates the prevalence of antibiotic resistance among bacterial isolates from dairy effluent sample of two different seasons from Verka Milk Plant, Mohali. Twenty bacteria were isolated by spread plating and streaking method. Variable amount of reduction in BOD and COD was observed in dairy effluentafter the treatment with free and immobilized seven bacterial strains i.e. A3, A8, A11, A13, A19, A21 and A23. Bacterial isolates with degrading efficiency were identified on...

  9. Novel biodegradable polyesteramide microspheres for controlled drug delivery in Ophthalmology.

    Science.gov (United States)

    Andrés-Guerrero, Vanessa; Zong, Mengmeng; Ramsay, Eva; Rojas, Blanca; Sarkhel, Sanjay; Gallego, Beatriz; de Hoz, Rosa; Ramírez, Ana I; Salazar, Juan José; Triviño, Alberto; Ramírez, José M; Del Amo, Eva M; Cameron, Neil; de-Las-Heras, Beatriz; Urtti, Arto; Mihov, George; Dias, Aylvin; Herrero-Vanrell, Rocío

    2015-08-10

    Most of the posterior segment diseases are chronic and multifactorial and require long-term intraocular medication. Conventional treatments of these pathologies consist of successive intraocular injections, which are associated with adverse effects. Successful therapy requires the development of new drug delivery systems able to release the active substance for a long term with a single administration. The present work involves the description of a new generation of microspheres based on poly(ester amide)s (PEA), which are novel polymers with improved biodegradability, processability and good thermal and mechanical properties. We report on the preparation of the PEA polymer, PEA microspheres (PEA Ms) and their characterization. PEA Ms (~15μm) were loaded with a lipophilic drug (dexamethasone) (181.0±2.4μg DX/mg Ms). The in vitro release profile of the drug showed a constant delivery for at least 90days. Based on the data from a performed in vitro release study, a kinetic ocular model to predict in vivo drug concentrations in a rabbit vitreous was built. According to the pharmacokinetic simulations, intravitreal injection of dexamethasone loaded PEA microspheres would provide release of the drug in rabbit eyes up to 3months. Cytotoxicity studies in macrophages and retinal pigment epithelial cells revealed a good in vitro tolerance of the microsystems. After sterilization, PEA Ms were administered in vivo by subtenon and intravitreal injections in male Sprague-Dawley rats and the location of the microspheres in rat eyes was monitored. We conclude that PEA Ms provide an alternative delivery system for controlling the delivery of drugs to the eye, allowing a novel generation of microsphere design. PMID:26003040

  10. Intracellular delivery mechanism and brain delivery kinetics of biodegradable cationic bovine serum albumin-conjugated polymersomes

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    Pang Z

    2012-07-01

    Full Text Available Zhiqing Pang,1,2 Huile Gao,1,2 Jun Chen,1,2 Shun Shen,1,2 Bo Zhang,3 Jinfeng Ren,1,2 Liangran Guo,1,2 Yong Qian,1,2 Xinguo Jiang,1,2 Heng Mei31Department of Pharmaceutics, School of Pharmacy, 2Key Laboratory of Smart Drug Delivery, Ministry of Education and PLA, Fudan University, Shanghai, 3Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of ChinaBackground: A novel brain drug delivery system using cationic bovine serum albumin (CBSA-conjugated biodegradable polymersomes (CBSA-PO was prepared, and its intracellular delivery mechanism and brain delivery kinetics were evaluated.Methods and results: Biodegradable poly(ethylene glycol-poly(ε -caprolactone (PEG-PCL was used to prepare the polymersomes, and thiolated CBSA was conjugated with the surface of the polymersome. Transmission electron microscopy and dynamic light scattering showed that the CBSA-PO had a round and vesicle-like shape, with a mean diameter of around 100 nm. Coupling of CBSA with polymersomes was confirmed by X-ray photoelectron spectroscopy. Uptake of CBSA-PO by bEnd.3 cells was significantly higher than that of unconjugated polymersomes, but was inhibited by low temperature, free CBSA, and poly-L-lysine, indicating that endocytosis was energy-driven and absorptive-mediated. Cell viability assays confirmed the good safety profile of biodegradable CBSA-PO. Pharmacokinetic results demonstrated that the polymersomes had long circulation times, and CBSA conjugation on the polymersomes significantly increased the blood–brain barrier permeability surface area product by 3.6-fold and the percentage of injected dose per gram brain (% ID/g brain by 2.1-fold. Capillary depletion experiments showed that CBSA-PO was distributed into the brain parenchyma in a time-dependent manner, with few polymersomes detected, indicating that conjugation of polymersomes with CBSA significantly improved their

  11. In vivo response to biodegradable controlled antibiotic release systems.

    Science.gov (United States)

    Korkusuz, F; Korkusuz, P; Ekşioĝlu, F; Gürsel, I; Hasirci, V

    2001-05-01

    In this study, the major goal was to evaluate in vitro and in vivo findings by macroscopy, radiology, and histology to determine the effectiveness of therapy of experimental implant-related osteomyelitis with antibiotic carrier rods constructed of microbial polyesters. The polymers used were poly(3-hydroxybutyrate-co-4-hydroxyvalerate) [P(3-HB-co-4-HB)] and poly(3-hydroxybutyrate-co-3-hydroxy- valerate) [P(3-HB-co-3-HV)]. Both the Sulperazone and the Duocid-P(3-HB-co-4-HB) rods with a drug to polymer ratio of 1:1 (w/w) were effective in treating the bone infection that was experimentally initiated by inoculation of a hemolytic strain of Staphylococcus aureus (coagulase positive; phage type 52/52b) together with metal implants into the medullary area of rabbit tibia. Macroscopical data revealed that the effectiveness of therapy was apparent at week 6 for all categories tested. Radiological findings with Duocid- and Sulperazone-loaded P(3-HB-co-4-HB) rods improved significantly when judged by changes in periosteal elevation, widening of bone shaft, new bone formation, and soft-tissue deformation after 6 weeks of implantation. Histologically the signs of infection were found to subside by weeks 3 and 6. Inflammatory cells were replaced with bone-forming cells upon treatment with Sulperazone-P(3-HB-co-4-HB) and Duocid-P(3-HB-co-4-HB). Osteoblastic activity was prominent. Intramedullary inflammation, although still present, started to be replaced by fibrous or bony tissue. Histological findings presented the subsidence of infection. In summary, the antibiotic-loaded biopolymeric rods appeared to have potential as a new controlled-release system for the treatment of implant related osteomyelitis and chronic osteomyelitis. PMID:11255173

  12. Dual delivery of active antibactericidal agents and bone morphogenetic protein at sustainable high concentrations using biodegradable sheath-core-structured drug-eluting nanofibers.

    Science.gov (United States)

    Hsu, Yung-Hen; Lin, Chang-Tun; Yu, Yi-Hsun; Chou, Ying-Chao; Liu, Shih-Jung; Chan, Err-Cheng

    2016-01-01

    In this study, we developed biodegradable sheath-core-structured drug-eluting nanofibers for sustainable delivery of antibiotics (vancomycin and ceftazidime) and recombinant human bone morphogenetic protein (rhBMP-2) via electrospinning. To prepare the biodegradable sheath-core nanofibers, we first prepared solutions of poly(d,l)-lactide-co-glycolide, vancomycin, and ceftazidime in 1,1,1,3,3,3-hexafluoro-2-propanol and rhBMP-2 in phosphate-buffered solution. The poly(d,l)-lactide-co-glycolide/antibiotics and rhBMP-2 solutions were then fed into two different capillary tubes controlled by two independent pumps for coaxial electrospinning. The electrospun nanofiber morphology was observed under a scanning electron microscope. We further characterized the in vitro antibiotic release from the nanofibers via high-performance liquid chromatography and that of rhBMP-2 via enzyme-linked immunosorbent assay and alkaline phosphatase activity. We showed that the biodegradable coaxially electrospun nanofibers could release high vancomycin/ceftazidime concentrations (well above the minimum inhibition concentration [MIC]90) and rhBMP-2 for >4 weeks. These experimental results demonstrate that novel biodegradable nanofibers can be constructed with various pharmaceuticals and proteins for long-term drug deliveries. PMID:27574423

  13. Fibrin sealant as a carrier for sustained delivery of antibiotics

    Directory of Open Access Journals (Sweden)

    Selçuk Kara

    2014-06-01

    Full Text Available Objective: To evaluate the activity and sustained release of antibiotics from fibrin sealant against common strains of ocular bacteria. Methods: Vancomycin, ceftazidime, moxifloxacin and lomefloxacin were incorporated into fibrin sealant in the shape of discs. Each antibiotic disc and control fibrin disc without drug was tested in vitro against standard bacterial strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae and Pseudomonas aeroginosa. After 24 hours of incubation at 37 °C, the discs were transferred to new plates of bacteria and triplicated for each antibiotic. Results: All antibiotic discs demonstrated detectable activity after 24 hours. Vancomycin had the longest duration of activity (4 days on the S. pneumonia grown plate. The moxifloxacin discs showed a prolonged inhibition of S. aureus and S. pneumonia for 3 days and inhibited the other strains for 2 days. Conclusion: Fibrin sealants provided prolonged drug delivery, which indicates that antibiotic-loaded fibrin clots could be useful for early ocular postoperative care and treatment. J Clin Exp Invest 2014; 5 (2: 194-199

  14. Silicon microneedles array with biodegradable tips for transdermal drug delivery

    CERN Document Server

    Chen, B; Tay, Francis; Wong, Y T; Iliescu, C

    2008-01-01

    This paper presents the fabrication process, characterization results and basic functionality of silicon microneedles array with biodegradable tips. In order to avoid the main problems related to silicon microneedles : broking of the top part of the needles inside the skin, a simple solution can be fabrication of microneedles array with biodegradable tips. The silicon microneedles array was fabricated by using reactive ion etching while the biodegradable tips were performed using and anodization process that generates selectively porous silicon only on the top part of the skin. The paper presents also the results of in vitro release of calcein using microneedles array with biodegradable tips

  15. A biodegradable perivascular wrap for controlled, local and directed drug delivery

    OpenAIRE

    Sanders, William G.; Hogrebe, Paul C.; Grainger, David W.; Cheung, Alfred K.; Terry, Christi M.

    2012-01-01

    Perivascular delivery of anti-proliferative agents is an attractive approach to inhibit hyperplasia that causes stenosis of synthetic hemodialysis grafts and other vascular grafts. Perivascular drug delivery systems typically release drugs to both the vascular wall and non-target extravascular tissue. The objective of this study was to develop a biodegradable, perivascular delivery system for localized, sustained and unidirectional drug release in the context of synthetic arteriovenous (AV) g...

  16. Antibiotics and sweeteners in the aquatic environment: biodegradability, formation of phototransformation products, and in vitro toxicity.

    Science.gov (United States)

    Bergheim, Marlies; Gminski, Richard; Spangenberg, Bernd; Debiak, Malgorzata; Bürkle, Alexander; Mersch-Sundermann, Volker; Kümmerer, Klaus; Gieré, Reto

    2015-11-01

    In the present study, in vitro toxicity as well as biopersistence and photopersistence of four artificial sweeteners (acesulfame, cyclamate, saccharine, and sucralose) and five antibiotics (levofloxacin, lincomycin, linezolid, marbofloxacin, and sarafloxacin) and of their phototransformation products (PTPs) were investigated. Furthermore, antibiotic activity was evaluated after UV irradiation and after exposure to inocula of a sewage treatment plant. The study reveals that most of the tested compounds and their PTPs were neither readily nor inherently biodegradable in the Organisation for Economic Co-operation and Development (OECD)-biodegradability tests. The study further demonstrates that PTPs are formed upon irradiation with an Hg lamp (UV light) and, to a lesser extent, upon irradiation with a Xe lamp (mimics sunlight). Comparing the nonirradiated with the corresponding irradiated solutions, a higher chronic toxicity against bacteria was found for the irradiated solutions of linezolid. Neither cytotoxicity nor genotoxicity was found in human cervical (HeLa) and liver (Hep-G2) cells for any of the investigated compounds or their PTPs. Antimicrobial activity of the tested fluoroquinolones was reduced after UV treatment, but it was not reduced after a 28-day exposure to inocula of a sewage treatment plant. This comparative study shows that PTPs can be formed as a result of UV treatment. The study further demonstrated that UV irradiation can be effective in reducing the antimicrobial activity of antibiotics, and consequently may help to reduce antimicrobial resistance in wastewaters. Nevertheless, the study also highlights that some PTPs may exhibit a higher ecotoxicity than the respective parent compounds. Consequently, UV treatment does not transform all micropollutants into harmless compounds and may not be a large-scale effluent treatment option. PMID:26169816

  17. Biodegradable Oxamide-Phenylene-Based Mesoporous Organosilica Nanoparticles with Unprecedented Drug Payloads for Delivery in Cells

    KAUST Repository

    Croissant, Jonas

    2016-06-03

    We describe biodegradable mesoporous hybrid NPs in the presence of proteins, and its application for drug delivery. We synthesized oxamide-phenylene-based mesoporous organosilica nanoparticles (MON) in the absence of silica source which had a remarkably high organic content with a high surface area. Oxamide functions provided biodegradability in the presence of trypsin model proteins. MON displayed exceptionally high payloads of hydrophilic and hydrophobic drugs (up to 84 wt%), and a unique zero premature leakage without the pore capping, unlike mesoporous silica. MON were biocompatible and internalized into cancer cells for drug delivery.

  18. Biodegradable star-like carriers for controlled drug delivery

    Czech Academy of Sciences Publication Activity Database

    Kostková, Hana; Kostka, Libor; Pola, Robert; Pechar, Michal; Filippov, Sergey K.; Ulbrich, Karel; Etrych, Tomáš

    Salt Lake City : The University of Utah, 2015. P33. [International Symposium on Recent Advances in Drug Delivery Systems /17./. 14.06.2015-17.06.2015, Salt Lake City] R&D Projects: GA ČR(CZ) GC15-10527J Institutional support: RVO:61389013 Keywords : star polymer * drug delivery * doxorubicin Subject RIV: CD - Macromolecular Chemistry

  19. Biodegradable nanoparticles obtained from zein as a drug delivery system for terpinen-4-ol

    Directory of Open Access Journals (Sweden)

    Vanderléia G. Marini

    2014-06-01

    Full Text Available Biodegradable nanoparticles (NPs have received considerable attention because of their possible use in the development of strategies for the topical delivery of oils and therapeutic drugs, particularly when drug penetration in dermis is desired. Zein is a prolamine and is a promising material for the design of drug delivery systems. In this study, NPs were prepared with zein and were used to encapsulate and release terpinen-4-ol, which is a therapeutic agent for the treatment of melanoma. The results show that the zein NPs are promising nanostructured systems for the prolonged delivery of T4OL with potential applications in anti-melanoma therapy.

  20. Generating Elastic, Biodegradable Polyurethane/Poly(lactide-co-glycolide) Fibrous Sheets with Controlled Antibiotic Release via Two-Stream Electrospinning

    OpenAIRE

    Hong, Yi; FUJIMOTO, KAZURO; Hashizume, Ryotaro; Guan, Jianjun; Stankus, John J.; Tobita, Kimimasa; Wagner, William R.

    2008-01-01

    Damage control laparotomy is commonly applied to prevent compartment syndrome following trauma but is associated with new risks to the tissue, including infection. To address the need for biomaterials to improve abdominal laparotomy management, we fabricated an elastic, fibrous composite sheet with two distinct submicrometer fiber populations: biodegradable poly(ester urethane) urea (PEUU) and poly(lactide-co-glycolide) (PLGA), where the PLGA was loaded with the antibiotic tetracycline hydroc...

  1. Development of biodegradable starch microspheres for intranasal delivery

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    Yadav A

    2008-01-01

    Full Text Available Domperidone microspheres for intranasal administration were prepared by emulsification crosslinking technique. Starch a biodegradable polymer was used in preparation of microspheres using epichlorhydrine as cross-linking agent. The formulation variables were drug concentration and polymer concentration and batch of drug free microsphere was prepared for comparisons. All the formulations were evaluated for particle size, morphological characteristics, percentage drug encapsulation, equilibrium swelling degree, percentage mucoadhesion, bioadhesive strength, and in vitro diffusion study using nasal cell. Spherical microspheres were obtained in all batches with mean diameter in the range of above 22.8 to 102.63 μm. They showed good mucoadhesive property and swelling behaviour. The in vitro release was found in the range of 73.11% to 86.21%. Concentration of both polymer and drug affect in vitro release of drug.

  2. 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.

  3. Mannosylated biodegradable polyethyleneimine for targeted DNA delivery to dendritic cells

    Directory of Open Access Journals (Sweden)

    Sun X

    2012-06-01

    Full Text Available Xun Sun, Simu Chen, Jianfeng Han, Zhirong ZhangKey Laboratory of Drug Targeting and Drug Delivery System, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, People’s Republic of ChinaBackground: To establish a potential gene-delivery system with the ability to deliver plasmid DNA to dendritic cells (DCs more efficiently and specifically, we designed and synthesized a low-molecular-weight polyethyleneimine and triethyleneglycol polymer (PEI–TEG and a series of its mannosylated derivatives.Methods: PEI–TEG was synthesized from PEI2000 and PEI600 with TEG as the cross-linker. PEI–TEG was then linked to mannose via a phenylisothiocyanate bridge to obtain man-PEI–TEG conjugates. The DNA conveyance abilities of PEI–TEG, man-PEI–TEG, as well as control PEI25k were evaluated by measuring their zeta potential, particle size, and DNA-binding abilities. The in vitro cytotoxicity, cell uptake, and transfection efficiency of these PEI/DNA complexes were examined on the DC2.4 cell line. Finally, a maturation experiment evaluated the effect of costimulatory molecules CD40, CD80, and CD86 on murine bone marrow-derived DCs (BMDCs using flow cytometry.Results: PEI–TEG and man-PEI–TEG were successfully synthesized and were shown to retain the excellent properties of PEI25k for condensing DNA. Compared with PEI–TEG as well as PEI25k, the man-PEI–TEG had less cytotoxicity and performed better in both cellular uptake and transfection assays in vitro. The results of the maturation experiment showed that all the PEI/DNA complexes induced an adequate upregulation of surface markers for DC maturation.Conclusion: These results demonstrated that man-PEI–TEG can be employed as a DC-targeting gene-delivery system.Keywords: dendritic cells, DCs, mannose, polyethyleneimine, PEI, gene delivery

  4. Oleanolic Acid Delivery using Biodegradable Nanoparticles for Cancer Therapy

    OpenAIRE

    Man, KWD; Kwok, PCL; Lam, JKW

    2014-01-01

    Oleanolic acid (OA) is a naturally occurring pentacyclic triterpenoid widely found in Chinese herbs. It has been extensively studied owing to the beneficial effects such as hepatoprotection, anti-inflammatory and it is recently found to have anti-tumor ability. However, resembling the other hydrophobic drugs, it has poor water solubility and therefore very limited intestinal absorption when administrated orally. Investigations concerning the delivery of OA have been ...

  5. Polyphosphazenes: Multifunctional, Biodegradable Vehicles for Drug and Gene Delivery

    Directory of Open Access Journals (Sweden)

    Ian Teasdale

    2013-02-01

    Full Text Available Poly[(organophosphazenes] are a unique class of extremely versatile polymers with a range of applications including tissue engineering and drug delivery, as hydrogels, shape memory polymers and as stimuli responsive materials. This review aims to divulge the basic principles of designing polyphosphazenes for drug and gene delivery and portray the huge potential of these extremely versatile materials for such applications. Polyphosphazenes offer a number of distinct advantages as carriers for bioconjugates; alongside their completely degradable backbone, to non-toxic degradation products, they possess an inherently and uniquely high functionality and, thanks to recent advances in their polymer chemistry, can be prepared with controlled molecular weights and narrow polydispersities, as well as self-assembled supra-molecular structures. Importantly, the rate of degradation/hydrolysis of the polymers can be carefully tuned to suit the desired application. In this review we detail the recent developments in the chemistry of polyphosphazenes, relevant to drug and gene delivery and describe recent investigations into their application in this field.

  6. Development of biodegradable nanoparticles for liver-specific ribavirin delivery.

    Science.gov (United States)

    Ishihara, Tsutomu; Kaneko, Kohei; Ishihara, Tomoaki; Mizushima, Tohru

    2014-12-01

    Ribavirin is an antiviral drug used for the treatment of chronic hepatitis C. However, ribavirin induces severe side effects such as hemolytic anemia. In this study, we prepared biodegradable nanoparticles as ribavirin carriers to modulate the pharmacokinetics of the drug. The nanoparticles encapsulating ribavirin monophosphate (RMP) were prepared from the blend of poly(d,l-lactic acid) homopolymer and arabinogalactan (AG)-poly(l-lysine) conjugate by using the solvent diffusion method in the presence of iron (III). RMP was efficiently and stably embedded in the nanoparticles and gradually released for 37 days in phosphate-buffered saline at 37°C. The coating of AG on the nanoparticles surfaces was verified by measuring the zeta potentials and performing an aggregation test of the nanoparticles using galactose-binding lectin. Moreover, the nanoparticles were efficiently internalized in cultured HepG2 cells. Ribavirin was drastically accumulated to the liver of mice after intravenous administration of the RMP-loaded nanoparticles, after which the ribavirin content gradually decreased for at least 7 days. Our results indicated successful development of nanoparticles with dual functions, targeting to the liver and sustained release of ribavirin, and suggested that the present strategy could help to advance the clinical application of ribavirin as a therapeutic agent for chronic hepatitis C. PMID:25335768

  7. Biodegradable polycarbonate-based stimuli-responsive nanosystems for intracellular drug delivery

    OpenAIRE

    Chen, Wei

    2013-01-01

    Biodegradable nanosystems based on functional polycarbonate-based polymers have propelled the development of targeted and controlled drug and gene delivery. Functional polycarbonate-based polymers have overcome many drawbacks which limited the application of the common polyester materials in this area. It is apparent that recently introduced novel functionalities in polycarbonate-based polymers allowed the preparation of novel nanocarriers, which are bioresponsive (i.e. pH, temperature, and r...

  8. Biocompatible medical implant materials with binding sites for a biodegradable drug-delivery system

    OpenAIRE

    Al-Dubai H; Pittner G; Pittner F; Gabor F

    2011-01-01

    Haifa Al-Dubai1, Gisela Pittner1, Fritz Pittner1, Franz Gabor21Max F Perutz Laboratories, Department of Biochemistry, University of Vienna, Vienna, Austria; 2Department of Pharmaceutical Technology and Biopharmaceutics, Faculty of Life Sciences, University of Vienna, Vienna, AustriaAbstract: Feasibility studies have been carried out for development of a biocompatible coating of medical implant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading ...

  9. Biodegradable microcontainers as an oral drug delivery system for poorly soluble drugs.

    OpenAIRE

    Nielsen, Line Hagner; Nagstrup, Johan; Keller, Stephan Sylvest; Gordon, Sarah; Østergaard, Jesper; Rades, Thomas; Müllertz, Anette; Boisen, Anja

    2013-01-01

    PURPOSE: To fabricate microcontainers in biodegradable polylactic acid (PLLA) polymer films using hot embossing, and investigate the application of fabricated microcontainers as an oral drug delivery system for a poorly soluble drug.METHODS: For fabrication of the PLLA microcontainers, a film of PLLA was produced by spin coating. The film was heated above the polymer glass transition temperature (Tg), and a stamp was forced into the film. Following cooling of the film the stamp was removed, e...

  10. Loading, Release, Biodegradation, and Biocompatibility of a Nanovector Delivery System

    Science.gov (United States)

    Ferrai, Mauro; Tasciotti, Ennio

    2012-01-01

    A nanovector multistage system has been created to overcome or bypass sequential barriers within the human body, in order to deliver a therapeutic or imaging agent to a specific location. This innovation consists of a composition that includes two or more stages of particles, such that smaller, later-stage particles are contained in the larger, early-stage particles. An active agent, such as a therapeutic agent or imaging agent, is preferentially delivered and/or localized to a particular target site in the body of a subject. The multistage composition overcomes multiple biological barriers in the body. The multistage composition also allows for simultaneous delivery and localization at the same or different target sites of multiple active agents.

  11. Nanocomposites of Polyacrylic Acid Nanogels and Biodegradable Polyhydroxybutyrate for Bone Regeneration and Drug Delivery

    Directory of Open Access Journals (Sweden)

    Mikael Larsson

    2014-01-01

    Full Text Available Biodegradable cell scaffolds and local drug delivery to stimulate cell response are currently receiving much scientific attention. Here we present a nanocomposite that combines biodegradation with controlled release of lithium, which is known to enhance bone growth. Nanogels of lithium neutralized polyacrylic acid were synthesized by microemulsion-templated polymerization and were incorporated into a biodegradable polyhydroxybutyrate (PHB matrix. Nanogel size was characterized using dynamic light scattering, and the nanocomposites were characterized with regard to structure using scanning electron microscopy, mechanical properties using tensile testing, permeability using tritiated water, and lithium release in PBS using a lithium specific electrode. The nanogels were well dispersed in the composites and the mechanical properties were good, with a decrease in elastic modulus being compensated by increased tolerance to strain in the wet state. Approximately half of the lithium was released over about three hours, with the remaining fraction being trapped in the PHB for subsequent slow release during biodegradation. The prepared nanocomposites seem promising for use as dual functional scaffolds for bone regeneration. Here lithium ions were chosen as model drug, but the nanogels could potentially act as carriers for larger and more complex drugs, possibly while still carrying lithium.

  12. Biodegradable Microspheres as Hepatitis B Vaccine Delivery Systems

    Institute of Scientific and Technical Information of China (English)

    杨春; 贾文祥; 陈恬; 曾蔚; 杨远; 杨发龙; 谢轶; 杨维清; 周绍兵; 李孝红

    2003-01-01

    In order to investigate the immtmogenicity of the controlled-release microencapsulated hepatitis B vaccine in mice, polyethylene glycol-poly-dl-lactide (PELA) microspheres with entrapped HSsAg were prepared by double emulsion W/O/W based on solvent extraction methods. BALB/c mice were immunized with the encapsulated vaccine by oral feeding or injection. Blood samples were collected at 8th, 10th, 14th and 24th weeks, respectively, and the levels of antibody response were detected by EI.ISA. It was found that the scanning electron microscopy showed the prepared microspheres had smoothand spherical surface, suitable for vaccine delivery. Two groups of mice orally fed with the encapsulated or conventional recombinant vaccines, respectively, there sere showed no obvious difference in the IgG levels. At 14th week, the group injected with a single dose of encapsulated vaccine had a similar level of IgG response to the group injected with two doses of the recombination vaccine. At 24th week, the IgG levels of the group injected with two doses of encapsulated vaccine were higher than those of the group injected with two doses of the recombination vaccine. It concludes that Controlled-release microencapsulated hepatitis B vaccine possesses the feature of slowly releasing in v/vo and long times immtmogenicity.

  13. An experimental design approach to the preparation of pegylated polylactide-co-glicolide gentamicin loaded microparticles for local antibiotic delivery.

    Science.gov (United States)

    Dorati, Rossella; DeTrizio, Antonella; Genta, Ida; Grisoli, Pietro; Merelli, Alessia; Tomasi, Corrado; Conti, Bice

    2016-01-01

    The present paper takes into account the DOE application to the preparation process of biodegradable microspheres for osteomyelitis local therapy. With this goal gentamicin loaded polylactide-co-glycolide-copolyethyleneglycol (PLGA-PEG) microspheres were prepared and investigated. Two preparation protocols (o/w and w/o/w) with different process conditions, and three PLGA-PEG block copolymers with different compositions of lactic and glycolic acids and PEG, were tested. A Design Of Experiment (DOE) screening design was applied as an approach to scale up manufacturing step. The results of DOE screening design confirmed that w/o/w technique, the presence of salt and the 15%w/v polymer concentration positively affected the EE% (72.1-97.5%), and span values of particle size distribution (1.03-1.23), while salt addition alone negatively affected the yield process. Process scale up resulted in a decrease of gentamicin EE% that can be attributed to the high volume of water used to remove PVA and NaCl residues. The results of in vitro gentamicin release study show prolonged gentamicin release up to three months from the microspheres prepared with salt addition in the dispersing phase; the behavior being consistent with their highly compact structure highlighted by scanning electron microscopy analysis. The prolonged release of gentamicin is maintained even after embedding the biodegradable microspheres into a thermosetting composite gel made of chitosan and acellular bovine bone matrix (Orthoss® granules), and the microbiologic evaluation demonstrated the efficacy of the gentamicin loaded microspheres on Escherichia coli. The collected results confirm the feasibility of the scale up of microsphere manufacturing process and the high potential of the microparticulate drug delivery system to be used for the local antibiotic delivery to bone. PMID:26478386

  14. New biodegradable dextran-based hydrogels for protein delivery: Synthesis and characterization.

    Science.gov (United States)

    Pacelli, Settimio; Paolicelli, Patrizia; Casadei, Maria Antonietta

    2015-08-01

    A new derivative of dextran grafted with polyethylene glycol methacrylate through a carbonate bond (DEX-PEG-MA) has been synthesized and characterized. The photo-crosslinking reaction of DEX-PEG-MA allowed the obtainment of biodegradable networks tested for their mechanical and release properties. The new hydrogels were compared with those made of dextran methacrylate (DEX-MA), often employed as drug delivery systems of small molecules. The inclusion of PEG as a spacer created additional interactions among the polymeric chains improving the extreme fragility and lack of hardness typical of gels made of DEX-MA. Moreover, the different behavior in terms of swelling and degradability of the networks was able to affect the release of a model macromolecule over time, making DEX-PEG-MA matrices suitable candidates for the delivery of high molecular weight peptides. Interestingly, the combination of the two dextran derivatives showed intermediate ability to modulate the release of high molecular weight macromolecules. PMID:25933541

  15. Biodegradable PLGA-b-PEG polymeric nanoparticles: synthesis, properties, and nanomedical applications as drug delivery system

    International Nuclear Information System (INIS)

    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.

  16. Antibiotics

    Science.gov (United States)

    Antibiotics are powerful medicines that fight bacterial infections. Used properly, antibiotics can save lives. They either kill bacteria or ... natural defenses can usually take it from there. Antibiotics do not fight infections caused by viruses, such ...

  17. Dry powder inhalation versus wet nebulisation delivery of antibiotics in cystic fibrosis patients

    NARCIS (Netherlands)

    Westerman, E.M.; Heijerman, H.G.M.; Frijlink, H.W.

    2007-01-01

    Inhalation of antipseudomonal antibiotics is a cornerstone in treating cystic fibrosis patients. It has shown to be effective in slowing down the process of pulmonary deterioration and decreasing the incidence of infectious exacerbations. The focus is now on innovating drug delivery devices, sometim

  18. Construction of a controlled-release delivery system for pesticides using biodegradable PLA-based microcapsules.

    Science.gov (United States)

    Liu, Baoxia; Wang, Yan; Yang, Fei; Wang, Xing; Shen, Hong; Cui, Haixin; Wu, Decheng

    2016-08-01

    Conventional pesticides usually need to be used in more than recommended dosages due to their loss and degradation, which results in a large waste of resources and serious environmental pollution. Encapsulation of pesticides in biodegradable carriers is a feasible approach to develop environment-friendly and efficient controlled-release delivery system. In this work, we fabricated three kinds of polylactic acid (PLA) carriers including microspheres, microcapsules, and porous microcapsules for controlled delivery of Lambda-Cyhalothrin (LC) via premix membrane emulsification (PME). The microcapsule delivery system had better water dispersion than the other two systems. Various microcapsules with a high LC contents as much as 40% and tunable sizes from 0.68 to 4.6μm were constructed by manipulating the process parameters. Compared with LC technical and commercial microcapsule formulation, the microcapsule systems showed a significantly sustained release of LC for a longer period. The LC release triggered by LC diffusion and matrix degradation could be optimally regulated by tuning LC contents and particle sizes of the microcapsules. This multi-regulated release capability is of great significance to achieve the precisely controlled release of pesticides. A preliminary bioassay against plutella xylostella revealed that 0.68μm LC-loaded microcapsules with good UV and thermal stability exhibited an activity similar to a commercial microcapsule formulation. These results demonstrated such an aqueous microcapsule delivery system had a great potential to be further explored for developing an effective and environmentally friendly pesticide-release formulation. PMID:27062215

  19. Polylactide-polyglycolide antibiotic implants.

    Science.gov (United States)

    Garvin, Kevin; Feschuk, Connie

    2005-08-01

    Surgeons continually struggle to reduce orthopaedic infections, but no current treatment offers minimum side effects with maximum effectiveness. Antibiotics mixed in plaster of paris have been successful in treating large bony defects in patients with chronic osteomyelitis, and have the advantage of being well tolerated and absorbed by the body. Antibiotics impregnated in polymethylmethacrylate (PMMA) have offered local antibiotic delivery with some success. However, the effect of the antibiotic on the bone cement, the inconsistent elution of the antibiotic, and the need to remove the PMMA implant drives the need for a better system of antibiotic delivery. Polymers or copolymers of antibiotic-impregnated polylactic acid, polyglycolic acid or polyparadioxanone may provide an absorbable system for localized antibiotic delivery. Similar biodegradable systems used to treat small bone fractures have been successful with minimal side effects. In vitro studies have shown promising results of antibiotic elution from bioabsorbable microspheres and beads. Animal in vivo tests have shown that antibiotic impregnated polymers can successfully treat induced osteomyelitis in rabbits and dogs. These studies have provided consistent reproducible results, and now it is time to plan human trials to assess the efficacy of antibiotic microspheres implanted in infected bone and to plan in vivo and in vitro animal testing to investigate the feasibility of antibiotic-polymer-coated components. PMID:16056034

  20. Biodegradable double nanocapsule as a novel multifunctional carrier for drug delivery and cell imaging

    Directory of Open Access Journals (Sweden)

    Qian K

    2015-06-01

    Full Text Available Kun Qian,1,2 Jing Wu,1 Enqi Zhang,1 Yingge Zhang,3 Ailing Fu1 1School of Pharmaceutical Sciences, Southwest University, 2College of Plant Protection, Southwest University, Chongqing, People’s Republic of China; 3Institute of Pharmacology and Toxicology, Key Laboratory of Nanopharmacology and Nanotoxicology, Beijing Academy of Medical Sciences, Beijing, People’s Republic of China Abstract: Highly-efficient delivery of macromolecules into cells for both imaging and therapy (theranostics remains a challenge for the design of a delivery system. Here, we suggested a novel hybrid protein–lipid polymer nanocapsule as an effective and nontoxic drug delivery and imaging carrier. The biodegradable nanocapsules showed the typical double emulsion features, including fluorescently labeled bovine serum albumin shell, oil phase containing poly(lactic-co-glycolic acid and linoleic acid, and inner aqueous phase. The nanocapsules were spherical in shape, with an average size of about 180 nm. Proteins packed into the inner aqueous phase of the nanocapsules could be delivered into cells with high efficiency, and the fluorescence of the fluorescently labeled bovine serum albumin could be used for tracing the protein migration and cellular location. Further studies suggested that the co-delivery of transcription factor p53 and lipophilic drug paclitaxel with the nanocapsules acted synergistically to induce Hela cell apoptosis, and the fluorescence of apoptotic cells was clearly observed under a fluorescence microscope. Such multifunctional delivery system would have great potential applications in drug delivery and theranostic fields. Keywords: emulsion, protein transport, fluorescence labeling, theranostics, cell apoptosis

  1. Modeling and Analysis of Drug-Eluting Stents With Biodegradable PLGA Coating: Consequences on Intravascular Drug Delivery

    OpenAIRE

    Zhu, Xiaoxiang; Richard D. Braatz

    2014-01-01

    Increasing interests have been raised toward the potential applications of biodegradable poly(lactic-co-glycolic acid) (PLGA) coatings for drug-eluting stents in order to improve the drug delivery and reduce adverse outcomes in stented arteries in patients. This article presents a mathematical model to describe the integrated processes of drug release in a stent with PLGA coating and subsequent drug delivery, distribution, and drug pharmacokinetics in the arterial wall. The integrated model t...

  2. Antibiotics and sweeteners in the aquatic environment : biodegradability, formation of phototransformation products, and in vitro toxicity

    OpenAIRE

    Bergheim, Marlies; Gminski, Richard; Spangenberg, Bernd; Debiak, Malgorzata; Bürkle, Alexander; Mersch-Sundermann, Volker; Kümmerer, Klaus; Gieré, Reto

    2015-01-01

    In the present study, in vitro toxicity as well as biopersistence and photopersistence of four artificial sweeteners (acesulfame, cyclamate, saccharine, and sucralose) and five antibiotics (levofloxacin, lincomycin, linezolid, marbofloxacin, and sarafloxacin) and of their phototransformation products (PTPs) were investigated. Furthermore, antibiotic activity was evaluated after UV irradiation and after exposure to inocula of a sewage treatment plant. The study reveals that most of the tested ...

  3. Drug release control in delivery system for biodegradable polymer drugs by γ-radiation

    International Nuclear Information System (INIS)

    Characterizations of the drug release from microsphere and hydrogel preparation made from biodegradable polymers were investigated aiming at development of a drug delivery system which allows an optimum drug delivery and the identification of the factors which control its delivery. Poly-lactic acid microspheres containing 10% of progesterone were produced from poly DL-lactic acid and exposed to γ-ray at 5-1000 kGy. And its glass transition temperature (Tg) was determined by differential scanning calorimetry. The temperature was gradually lowered with an increase in the dose of radiation. Tg of the microsphere exposed at 1000 kGy was lower by 10degC compared with the untreated one, showing that Tg control is possible without changing the size distribution of microsphere. Then, the amount of progesterone released from microsphere was determined. The release rate of the drug linearly increased with a square root of radiation time. These results indicate that the control of drug release rate is possible through controling the microsphere's Tg by γ-ray radiation. (M.N.)

  4. Control of drug release from biodegradable polymer drug delivery system by γ-ray irradiation

    International Nuclear Information System (INIS)

    This study aimed to develop a drug delivery system of superior drug releasing properties and to find factors to control the properties of microspheric and hydrogel polymers. Further, techniques to control the drug release properties by γ-ray exposure were investigated. The effects of gelatin concentration and the degree of cross linkage on the release rate of temperature-responding hydrogel were investigated in the previous year. In this year, the mobility of a hydrogel polymer was investigated using dynamic light scattering photometry. Biodegradable polymer such as dextran, gelatin, polyhydroxyethylaspartamide was dissolved in dimethylaminopyridine and incubated with glycidylymethacrylamide to produce its methacryl derivatives and the polymer solution was exposed to γ-ray in the presence of a drug. Then, 1H-NMR spin-spin relaxation time was determined for estimation of mobility and mesh size of the polymer. In addition, the drug release rate for the hydrogel polymer after γ-ray exposure was estimated. The drug release rate of hydrogel was demonstrated to be dependent on its mesh size and the mobility of the polymer was closely correlated to the mesh size. Thus it was demonstrated that spin-spin relaxation time (T2) was available as an indicator for mobility of gel-like polymers. Up to now, synthetic polymers that were not biodegradable have been used as stimuli-responding gel. However, it became possible to produce a stimuli-responding gel by the hydrogel preparation method using γ-ray irradiation. (M.N.)

  5. Increased Release Time of Antibiotics from Bone Allografts through a Novel Biodegradable Coating

    OpenAIRE

    2014-01-01

    The use of bone allografts is contraindicated in septic revision surgery due to the high risk of graft reinfection. Antibiotic release from the graft may solve the problem and these combinations can theoretically be used for prevention or even therapy of infection. The present study investigated whether amoxicillin, ciprofloxacin, and vancomycin alone or in combination with chitosan or alginate are suitable for short-term or long-term bone coating. Human bone allografts were prepared from fem...

  6. Synthesis of Biodegradable Polymer Micro- and Nanoparticles for Controlled Drug Delivery by Multiplexed Electrosprays

    Science.gov (United States)

    Almeria, Begona

    The goal of controlled drug delivery is to administer sustained amounts of a therapeutic agent over a prolonged period of time, improving the drug efficacy as compared to conventional, bolus doses that lead to variable concentrations of drug in blood. Although there are several systems capable to provide such a continuous-dose-based treatment, the use of biodegradable polymer micro- and, especially, nanoparticles offers multiple advantages with respect to other platforms. Their small size allows them to pass through physical barriers in the body and reach the site of treatment, allowing for a localized delivery, reducing side effects and toxicity. Polymer nanoparticles have lower clearance by the immune system, and are especially useful in intracellular delivery, delivery to the lymphatic system and the treatment of tumors, where the site of treatment is difficult to reach by larger particles. Conventional methods for biodegradable particle production rely predominately on batch, emulsion preparation methods and suffer from several shortcomings: low encapsulation efficiency (˜10% for hydrophilic drugs), difficulty to generate sufficiently small (dadvantages and overcomes all of these limitations. We demonstrate this process with the Poly(DL-lactic-co-glycolic acid) (PLGA) system encapsulating agents such as Doxorubicin, Rhodamine B and Rhodamine B octadecyl ester prechlorate. We also employ this method for the generation of theranostic systems that combine their therapeutic mission with imaging capabilities to detect the biodistribution of particles inside the body. PLGA microparticles in different sizes, morphologies and compactness are generated using the electrospray-drying route. The size of the synthesized particles is primarily controlled by the delicate tuning of the solution physical properties and the ES operational parameters. The compactness of the polymer matrix is defined by the competition between the solvent evaporation and polymer diffusion process

  7. Biodegradable thermoresponsive polymeric magnetic nanoparticles: a new drug delivery platform for doxorubicin

    International Nuclear Information System (INIS)

    The use of nanoparticles as drug delivery systems for anticancer therapeutics has great potential to revolutionize the future of cancer therapy. The aim of this study is to construct a novel drug delivery platform comprising a magnetic core and biodegradable thermoresponsive shell of tri-block-copolymer. Oleic acid-coated Fe3O4 nanoparticles and hydrophilic anticancer drug “doxorubicin” are encapsulated with PEO–PLGA–PEO (polyethylene oxide–poly d, l lactide-co-glycolide–polyethylene oxide) tri-block-copolymer. Structural, magnetic, and physical properties of Fe3O4 core are determined by X-ray diffraction, vibrating sample magnetometer, and transmission electron microscopy techniques, respectively. The hydrodynamic size of composite nanoparticles is determined by dynamic light scattering and is found to be ∼36.4 nm at 25 °C. The functionalization of magnetic core with various polymeric chain molecules and their weight proportions are determined by Fourier transform infrared spectroscopy and thermogravimetric analysis, respectively. Encapsulation of doxorubicin into the polymeric magnetic nanoparticles, its loading efficiency, and kinetics of drug release are investigated by UV–vis spectroscopy. The loading efficiency of drug is 89% with a rapid release for the initial 7 h followed by the sustained release over a period of 36 h. The release of drug is envisaged to occur in response to the physiological temperature by deswelling of thermoresponsive PEO–PLGA–PEO block-copolymer. This study demonstrates that temperature can be exploited successfully as an external parameter to control the release of drug.

  8. A novel, biodegradable and reversible polyelectrolyte platform for topical-colonic delivery of pentosan polysulphate.

    Science.gov (United States)

    Shah, Hardik K; Conkie, Jim A; Tait, Robert C; Johnson, James R; Wilson, Clive G

    2011-02-14

    The goal of the present work was to develop a swellable hydrogel colonic delivery system, which would maximise the availability of the therapeutic agent at a site of inflammation, especially where the water is scarce. A novel method was developed to manufacture a biodegradable and reversible polyelectrolyte complex (PEC) containing chitosan and poly acrylic-acid (PAA). The PEC was analysed using FTIR and DSC, which confirmed the formation of non-permanent swollen gel-network at an alkaline pH. Pentosan polysulphate (PPS) was incorporated in a PEC and an activated partial thromboplastin time assay was developed to measure the release of PPS from PEC. In vitro studies suggested that the release of PPS was dependent on the initial drug loading and the composition of the PEC. The gel strength of the swollen network, determined using a texture analyser, was dependent on polymer composition and the amount of PPS incorporated. Bacterial enzymes were collected from the rat caecum and colon for the digestion studies and characterised for glucosidase activity, glucuronidase activity and protein content. The digestion of the reversible polyelectrolyte complexes was measured using a dinitro salicylic acid assay and an increased release of drug was also confirmed in the presence of bacterial enzymes. PMID:21093555

  9. Design, Characterization, and Optimization of Controlled Drug Delivery System Containing Antibiotic Drug/s.

    Science.gov (United States)

    Patel, Apurv; Dodiya, Hitesh; Shelate, Pragna; Shastri, Divyesh; Dave, Divyang

    2016-01-01

    The objective of this work was design, characterization, and optimization of controlled drug delivery system containing antibiotic drug/s. Osmotic drug delivery system was chosen as controlled drug delivery system. The porous osmotic pump tablets were designed using Plackett-Burman and Box-Behnken factorial design to find out the best formulation. For screening of three categories of polymers, six independent variables were chosen for Plackett-Burman design. Osmotic agent sodium chloride and microcrystalline cellulose, pore forming agent sodium lauryl sulphate and sucrose, and coating agent ethyl cellulose and cellulose acetate were chosen as independent variables. Optimization of osmotic tablets was done by Box-Behnken design by selecting three independent variables. Osmotic agent sodium chloride, pore forming agent sodium lauryl sulphate, and coating agent cellulose acetate were chosen as independent variables. The result of Plackett-Burman and Box-Behnken design and ANOVA studies revealed that osmotic agent and pore former had significant effect on the drug release up to 12 hr. The observed independent variables were found to be very close to predicted values of most satisfactory formulation which demonstrates the feasibility of the optimization procedure in successful development of porous osmotic pump tablets containing antibiotic drug/s by using sodium chloride, sodium lauryl sulphate, and cellulose acetate as key excipients. PMID:27610247

  10. Highly stable, protein capped gold nanoparticles as effective drug delivery vehicles for amino-glycosidic antibiotics

    International Nuclear Information System (INIS)

    A method for the production of highly stable gold nanoparticles (Au NP) was optimized using sodium borohydride as reducing agent and bovine serum albumin as capping agent. The synthesized nanoparticles were characterized using UV–visible spectroscopy, transmission electron microscopy, X‐ray diffraction (XRD) and dynamic light scattering techniques. The formation of gold nanoparticles was confirmed from the appearance of pink colour and an absorption maximum at 532 nm. These protein capped nanoparticles exhibited excellent stability towards pH modification and electrolyte addition. The produced nanoparticles were found to be spherical in shape, nearly monodispersed and with an average particle size of 7.8 ± 1.7 nm. Crystalline nature of the nanoparticles in face centered cubic structure is confirmed from the selected‐area electron diffraction and XRD patterns. The nanoparticles were functionalized with various amino-glycosidic antibiotics for utilizing them as drug delivery vehicles. Using Fourier transform infrared spectroscopy, the possible functional groups of antibiotics bound to the nanoparticle surface have been examined. These drug loaded nanoparticle solutions were tested for their antibacterial activity against Gram-negative and Gram-positive bacterial strains, by well diffusion assay. The antibiotic conjugated Au NP exhibited enhanced antibacterial activity, compared to pure antibiotic at the same concentration. Being protein capped and highly stable, these gold nanoparticles can act as effective carriers for drugs and might have considerable applications in the field of infection prevention and therapeutics. - Highlights: ► Method for NaBH4 reduced and BSA capped gold nanoparticle was standardized. ► Nanoparticles were spherical and nearly monodispersed with a size of 7.8 nm. ► Nanoparticles are extremely stable towards pH modification and electrolyte addition. ► Antibiotic conjugated nanoparticles exhibited enhanced antibacterial activity

  11. Core–shell composite particles composed of biodegradable polymer particles and magnetic iron oxide nanoparticles for targeted drug delivery

    International Nuclear Information System (INIS)

    Core–shell composite particles with biodegradability and superparamagnetic behavior were prepared using a Pickering emulsion for targeted drug delivery based on magnetic guidance. The composite particles were composed of a core of biodegradable polymer and a shell of assembled magnetic iron oxide nanoparticles. It was found that the dispersibility of the nanoparticles is crucial for controlling the core–shell structure. The addition of a small amount of dispersant into the nanoparticle's suspension could improve the dispersibility and led to the formation of composite particles with a thin magnetic shell covering a polymeric core. The composite particles were also fabricated with a model drug loaded into the core, which was released via hydrolysis of the core under strong alkaline conditions. Because the core can also be biodegraded by lipase, this result suggests that the slow release of the drug from the composite particles should occur inside the body. - Highlights: • Core−shell composites with biodegradability and magnetism are prepared. • O/W emulsion stabilized by iron oxide nanoparticles is utilized for the preparation. • The nanoparticle's dispersibility is crucial for controlling the composite structure. • Composites loading a model drug are also prepared. • The model drug is released with decomposition of the composites

  12. Core–shell composite particles composed of biodegradable polymer particles and magnetic iron oxide nanoparticles for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Chiemi; Ushimaru, Kazunori [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Horiishi, Nanao [Bengala Techno Laboratory, 9-5-1006, 1-1 Kodai, Miyamae-ku, Kawasaki 216-0007 (Japan); Tsuge, Takeharu [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kitamoto, Yoshitaka, E-mail: kitamoto.y.aa@m.titech.ac.jp [Department of Innovative and Engineered Materials, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

    2015-05-01

    Core–shell composite particles with biodegradability and superparamagnetic behavior were prepared using a Pickering emulsion for targeted drug delivery based on magnetic guidance. The composite particles were composed of a core of biodegradable polymer and a shell of assembled magnetic iron oxide nanoparticles. It was found that the dispersibility of the nanoparticles is crucial for controlling the core–shell structure. The addition of a small amount of dispersant into the nanoparticle's suspension could improve the dispersibility and led to the formation of composite particles with a thin magnetic shell covering a polymeric core. The composite particles were also fabricated with a model drug loaded into the core, which was released via hydrolysis of the core under strong alkaline conditions. Because the core can also be biodegraded by lipase, this result suggests that the slow release of the drug from the composite particles should occur inside the body. - Highlights: • Core−shell composites with biodegradability and magnetism are prepared. • O/W emulsion stabilized by iron oxide nanoparticles is utilized for the preparation. • The nanoparticle's dispersibility is crucial for controlling the composite structure. • Composites loading a model drug are also prepared. • The model drug is released with decomposition of the composites.

  13. pH-responsive and biodegradable polymeric nanoparticles with potential application as tumour-specific drug delivery containers

    Czech Academy of Sciences Publication Activity Database

    Jäger, Eliezer; Giacomelli, F. C.; Jäger, Alessandro; Giacomelli, C.; Schmidt, V.; Ulbrich, Karel; Štěpánek, Petr

    Bratislava : Young Scientists Council of Polymer Institute of Slovak Academy of Sciences, 2012 - (Podhradská, S.; Šišková, A.). s. 65-66 ISBN 978-80-970923-2-0. [Bratislava Young Polymer Scientists Workshop /4./ - BYPOS 2012. 01.10.2012-05.10.2012, Liptovský Ján] R&D Projects: GA ČR GAP208/10/1600; GA AV ČR IAAX00500803 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : pH-responsive nanoparticles * biodegradable nanoparticles * drug-delivery Subject RIV: CD - Macromolecular Chemistry

  14. Biodegradable Chitosan Nanoparticle Coatings on Titanium for the Delivery of BMP-2

    OpenAIRE

    Nils Poth; Virginia Seiffart; Gerhard Gross; Henning Menzel; Wibke Dempwolf

    2015-01-01

    A simple method for the functionalization of a common implant material (Ti6Al4V) with biodegradable, drug loaded chitosan-tripolyphosphate (CS-TPP) nanoparticles is developed in order to enhance the osseointegration of endoprostheses after revision operations. The chitosan used has a tailored degree of acetylation which allows for a fast biodegradation by lysozyme. The degradability of chitosan is proven via viscometry. Characteristics and degradation of nanoparticles formed with TPP are anal...

  15. Antibiotics.

    Science.gov (United States)

    Hariprasad, Seenu M; Mieler, William F

    2016-01-01

    The Endophthalmitis Vitrectomy Study (EVS) provided ophthalmologists with evidence-based management strategies to deal with endophthalmitis for the first time. However, since the completion of the EVS, numerous unresolved issues remain. The use of oral antibiotics has important implications for the ophthalmologist, particularly in the prophylaxis and/or management of postoperative, posttraumatic, or bleb-associated bacterial endophthalmitis. One can reasonably conclude that significant intraocular penetration of an antibiotic after oral administration may be a property unique to the newer-generation fluoroquinolones. Prophylactic use of mupirocin nasal ointment resulted in significant reduction of conjunctival flora with or without preoperative topical 5% povidone-iodine preparation. Ocular fungal infections have traditionally been very difficult to treat due to limited therapeutic options both systemically and intravitreally. Because of its broad spectrum of coverage, low MIC90 levels for the organisms of concern, good tolerability, and excellent bioavailability, voriconazole through various routes of administration may be useful to the ophthalmologist in the primary treatment of or as an adjunct to the current management of ocular fungal infections. PMID:26501865

  16. A biodegradable antibiotic-impregnated scaffold to prevent osteomyelitis in a contaminated in vivo bone defect model

    Directory of Open Access Journals (Sweden)

    JS McLaren

    2014-06-01

    Full Text Available Open fractures are at risk of serious infection and, if infected, require several surgical interventions and courses of systemic antibiotics. We investigated a new injectable formulation that simultaneously hardens in vivo to form a porous scaffold for bone repair and delivers antibiotics at high concentrations to the local site of infection. Duration of antimicrobial activity against Staphylococcus aureus was determined using the serial plate transfer test. Ultimate compressive strength and porosity of the material was measured with and without antibiotics. The material was evaluated in vivo in an ovine medial femoral condyle defect model contaminated with S. aureus. Sheep were sacrificed at either 2 or 13 weeks and the defect and surrounding bone assessed using micro-computed tomography and histology. Antimicrobial activity in vitro persisted for 19-21 days. Sheep with antibiotic-free material and bacteria became infected, while those with antibiotic-containing material and bacteria did not. Similarly, new bone growth was seen in uninoculated animals with plain polymer, and in those with antibiotic polymer with bacteria, but not in sheep with plain polymer and bacteria. The antibiotic-impregnated scaffolds were effective in preventing S. aureus infections whilst supporting bone growth and repair. If translated into clinical practice, this approach might reduce the need for systemic antibiotics.

  17. A biodegradable antibiotic-impregnated scaffold to prevent osteomyelitis in a contaminated in vivo bone defect model.

    Science.gov (United States)

    McLaren, J S; White, L J; Cox, H C; Ashraf, W; Rahman, C V; Blunn, G W; Goodship, A E; Quirk, R A; Shakesheff, K M; Bayston, R; Scammell, B E

    2014-01-01

    Open fractures are at risk of serious infection and, if infected, require several surgical interventions and courses of systemic antibiotics. We investigated a new injectable formulation that simultaneously hardens in vivo to form a porous scaffold for bone repair and delivers antibiotics at high concentrations to the local site of infection. Duration of antimicrobial activity against Staphylococcus aureus was determined using the serial plate transfer test. Ultimate compressive strength and porosity of the material was measured with and without antibiotics. The material was evaluated in vivo in an ovine medial femoral condyle defect model contaminated with S. aureus. Sheep were sacrificed at either 2 or 13 weeks and the defect and surrounding bone assessed using micro-computed tomography and histology. Antimicrobial activity in vitro persisted for 19-21 days. Sheep with antibiotic-free material and bacteria became infected, while those with antibiotic-containing material and bacteria did not. Similarly, new bone growth was seen in uninoculated animals with plain polymer, and in those with antibiotic polymer with bacteria, but not in sheep with plain polymer and bacteria. The antibiotic-impregnated scaffolds were effective in preventing S. aureus infections whilst supporting bone growth and repair. If translated into clinical practice, this approach might reduce the need for systemic antibiotics. PMID:24908426

  18. Preclinical development of biodegradable polymer foils for intracerebral delivery of cytotoxic nucleosides.

    Science.gov (United States)

    Grieb, Paweł; Ryba, Mirosław; Janisz, Monika; Walski, Michał

    2003-01-01

    Intracerebral implantation of biodegradable polymers loaded with cytotoxic or radiosensitising nucleoside analogues is a promising treatment strategy for malignant gliomas, which are currently intractable. The aim of the study was to develop biodegradable polymers containing nucleosides which could be implanted intracerebrally. Methods of synthesis were developed for the copolymers composed of D,L-lactide, glycolide and caprolactone in different proportions, as well as a novel method of introducing nucleosides to these copolymers at the polymerisation step. Upon degradation in an aqueous medium some of these copolymers emit nucleosides in micromolar concentration over several months. Their in situ degradation and biocompatibility with brain tissues was assessed by means of scanning and transmission electron microscopy. At the ultrastructural level tissue responses to the copolymer implantation closely resembled the responses to mechanical trauma. PMID:12899199

  19. Novel "soft" biodegradable nanoparticles prepared from aliphatic based monomers as a potential drug delivery system

    Czech Academy of Sciences Publication Activity Database

    Jäger, Alessandro; Gromadzki, Daniel; Jäger, Eliezer; Giacomelli, F. C.; Kozlowska, A.; Kobera, Libor; Brus, Jiří; Říhová, Blanka; El Fray, M.; Ulbrich, Karel; Štěpánek, Petr

    2012-01-01

    Roč. 8, č. 16 (2012), s. 4343-4354. ISSN 1744-683X R&D Projects: GA AV ČR IAAX00500803; GA ČR GAP208/10/1600 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Keywords : biodegradable nanoparticles * light scattering from polymer nanoparticles * drug release Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.909, year: 2012

  20. Injectable biodegradable carriers for the delivery of therapeutic agents and tissue engineering

    OpenAIRE

    Levato, Riccardo

    2015-01-01

    The design of smart biomaterial devices plays a key role to improve the way conventional therapies are being delivered, and to promote the development of new approaches for advanced therapies, such as regenerative medicine and targeted drug release. Injectable biodegradable materials, such as those consisting of suspensions of polymeric particles, are highly versatile devices that can be delivered through minimally-invasive injections. The physic-chemical properties of the particles can be en...

  1. Biodegradable Chitosan Nanoparticle Coatings on Titanium for the Delivery of BMP-2

    Directory of Open Access Journals (Sweden)

    Nils Poth

    2015-01-01

    Full Text Available A simple method for the functionalization of a common implant material (Ti6Al4V with biodegradable, drug loaded chitosan-tripolyphosphate (CS-TPP nanoparticles is developed in order to enhance the osseointegration of endoprostheses after revision operations. The chitosan used has a tailored degree of acetylation which allows for a fast biodegradation by lysozyme. The degradability of chitosan is proven via viscometry. Characteristics and degradation of nanoparticles formed with TPP are analyzed using dynamic light scattering. The particle degradation via lysozyme displays a decrease in particle diameter of 40% after 4 days. Drug loading and release is investigated for the nanoparticles with bone morphogenetic protein 2 (BMP-2, using ELISA and the BRE luciferase test for quantification and bioactivity evaluation. Furthermore, nanoparticle coatings on titanium substrates are created via spray-coating and analyzed by ellipsometry, scanning electron microscopy and X-ray photoelectron spectroscopy. Drug loaded nanoparticle coatings with biologically active BMP-2 are obtained in vitro within this work. Additionally, an in vivo study in mice indicates the dose dependent induction of ectopic bone growth through CS-TPP-BMP-2 nanoparticles. These results show that biodegradable CS-TPP coatings can be utilized to present biologically active BMP-2 on common implant materials like Ti6Al4V.

  2. Syntheses of amphiphilic biodegradable copolymers of poly(ethyl ethylene phosphate) and poly(3-hydroxybutyrate) for drug delivery

    Institute of Scientific and Technical Information of China (English)

    CHENG Jing; WANG Jun

    2009-01-01

    Biodegradable and amphiphilic triblock copolymers poly(ethyl ethylene phosphate)-poly(3-hydroxybutyrate)-poly(ethyl ethylene phosphate) (PEEP-b-PHB-b-PEEP) have been successfully synthesized through ring-opening polymerization.The structures are confirmed by gel permeation chromatography and NMR analyses.Crystallization investigated by X-ray diffraction reveals that the block copolymer with higher content of poly(ethyl ethylene phosphate) (PEEP) is more amorphous,showing decreased crystallizability.The obtained copolymers self-assemble into biodegradable nanoparticles with a coreshell micellar structure in aqueous solution,verified by the probe-based fluorescence measurements and transmission electronic microscopy (TEM) observation.The hydrophobic poly(3-hydroxybutyrate) (PHB) block serves as the core of the micelles and the micelles are stabilized by the hydrophilic PEEP block.The size and size distribution are related to the compositions of the copolymers.Paclitaxel (PTX) has been encapsulated into the micelles as a model drug and a sustained drug release from the micelles is observed.MTT assay also demonstrates that the block copolymers are biocompatible,rendering these copolymers attractive for drug delivery.

  3. Syntheses of amphiphilic biodegradable copolymers of poly(ethyl ethylene phosphate) and poly(3-hydroxybutyrate) for drug delivery

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Biodegradable and amphiphilic triblock copolymers poly(ethyl ethylene phosphate)-poly(3-hydroxybutyrate)-poly(ethyl ethylene phosphate) (PEEP-b-PHB-b-PEEP) have been successfully synthesized through ring-opening polymerization. The structures are confirmed by gel permeation chromatography and NMR analyses. Crystallization investigated by X-ray diffraction reveals that the block copolymer with higher content of poly(ethyl ethylene phosphate) (PEEP) is more amorphous, showing decreased crystallizability. The obtained copolymers self-assemble into biodegradable nanoparticles with a coreshell micellar structure in aqueous solution, verified by the probe-based fluorescence measurements and transmission electronic microscopy (TEM) observation. The hydrophobic poly(3-hydroxybutyrate) (PHB) block serves as the core of the micelles and the micelles are stabilized by the hydrophilic PEEP block. The size and size distribution are related to the compositions of the copolymers. Paclitaxel (PTX) has been encapsulated into the micelles as a model drug and a sustained drug release from the micelles is observed. MTT assay also demonstrates that the block copolymers are biocompatible, rendering these copolymers attractive for drug delivery.

  4. Antibacterial Efficiency of Hydroxyapatite Biomaterials with Biodegradable Polylactic Acid and Polycaprolactone Polymers Saturated with Antibiotics / Bionoārdāmu Polimēru Saturošu Un Ar Antibiotiskajām Vielām Piesūcinātu Biomateriālu Antibakteriālās Efektivitātes Noteikšana

    Directory of Open Access Journals (Sweden)

    Kroiča Juta

    2016-08-01

    Full Text Available Infections continue to spread in all fields of medicine, and especially in the field of implant biomaterial surgery, and not only during the surgery, but also after surgery. Reducing the adhesion of bacteria could decrease the possibility of biomaterial-associated infections. Bacterial adhesion could be reduced by local antibiotic release from the biomaterial. In this in vitro study, hydroxyapatite biomaterials with antibiotics and biodegradable polymers were tested for their ability to reduce bacteria adhesion and biofilm development. This study examined the antibacterial efficiency of hydroxyapatite biomaterials with antibiotics and biodegradable polymers against Staphylococcus epidermidis and Pseudomonas aeruginosa. The study found that hydroxyapatite biomaterials with antibiotics and biodegradable polymers show longer antibacterial properties than hydroxyapatite biomaterials with antibiotics against both bacterial cultures. Therefore, the results of this study demonstrated that biomaterials that are coated with biodegradable polymers release antibiotics from biomaterial samples for a longer period of time and may be useful for reducing bacterial adhesion on orthopedic implants.

  5. Disassembling bacterial extracellular matrix with DNase-coated nanoparticles to enhance antibiotic delivery in biofilm infections.

    Science.gov (United States)

    Baelo, Aida; Levato, Riccardo; Julián, Esther; Crespo, Anna; Astola, José; Gavaldà, Joan; Engel, Elisabeth; Mateos-Timoneda, Miguel Angel; Torrents, Eduard

    2015-07-10

    Infections caused by biofilm-forming bacteria are a major threat to hospitalized patients and the main cause of chronic obstructive pulmonary disease and cystic fibrosis. There is an urgent necessity for novel therapeutic approaches, since current antibiotic delivery fails to eliminate biofilm-protected bacteria. In this study, ciprofloxacin-loaded poly(lactic-co-glycolic acid) nanoparticles, which were functionalized with DNase I, were fabricated using a green-solvent based method and their antibiofilm activity was assessed against Pseudomonas aeruginosa biofilms. Such nanoparticles constitute a paradigm shift in biofilm treatment, since, besides releasing ciprofloxacin in a controlled fashion, they are able to target and disassemble the biofilm by degrading the extracellular DNA that stabilize the biofilm matrix. These carriers were compared with free-soluble ciprofloxacin, and ciprofloxacin encapsulated in untreated and poly(lysine)-coated nanoparticles. DNase I-activated nanoparticles were not only able to prevent biofilm formation from planktonic bacteria, but they also successfully reduced established biofilm mass, size and living cell density, as observed in a dynamic environment in a flow cell biofilm assay. Moreover, repeated administration over three days of DNase I-coated nanoparticles encapsulating ciprofloxacin was able to reduce by 95% and then eradicate more than 99.8% of established biofilm, outperforming all the other nanoparticle formulations and the free-drug tested in this study. These promising results, together with minimal cytotoxicity as tested on J774 macrophages, allow obtaining novel antimicrobial nanoparticles, as well as provide clues to design the next generation of drug delivery devices to treat persistent bacterial infections. PMID:25913364

  6. Paclitaxel loaded biodegradable poly (sebacic acid-co-ricinoleic acid cylindrical implants for local delivery-in vitro characterization

    Directory of Open Access Journals (Sweden)

    Jagadeesh G Hiremath

    2013-01-01

    Full Text Available The aim of the present research work was to develop the biodegradable polymeric implant for the delivery of antineoplastic drug, paclitaxel (PTX using poly (sebacic-co-recinoleic acid 70:30 w/w. PTX loaded implants were prepared by indigenously developed melt molding technique. Implants were characterized in terms of physico-chemical evaluations, drug content, drug stability and intactness, thermal analysis, drug physical state and crystallinity, surface morphology, hydrolytic degradation, drug release and its kinetics. Prepared implants were yellow and cylindrical in shape with smooth surfaces. Drug in the implants was found to be stable, intact and uniformly dispersed as amorphous state within the polymer matrix. In vitro release, kinetic studies showed zero order and Korsmeyer-Peppas model release being exhibited. Drug release from the polymeric implants was occurred could be as results of diffusion.

  7. A biodegradable antibiotic-impregnated scaffold to prevent osteomyelitis in a contaminated in vivo bone defect model

    OpenAIRE

    JS McLaren; LJ White; HC Cox; Ashraf, W; CV Rahman; GW Blunn; AE Goodship; RA Quirk; KM Shakesheff; Bayston, R; BE Scammell

    2014-01-01

    Open fractures are at risk of serious infection and, if infected, require several surgical interventions and courses of systemic antibiotics. We investigated a new injectable formulation that simultaneously hardens in vivo to form a porous scaffold for bone repair and delivers antibiotics at high concentrations to the local site of infection. Duration of antimicrobial activity against Staphylococcus aureus was determined using the serial plate transfer test. Ultimate compressive strength and ...

  8. A comparative study of the antibiotic utilization during the normal and caesarean section deliveries at Jawaharlal Nehru institute of medical sciences hospital, Imphal, Manipur, India

    Directory of Open Access Journals (Sweden)

    Joychandra Singh Oinam

    2016-06-01

    Conclusions: Pregnancy is just a natural process (not a disease or a medical condition and external intervention should occur only for sound medical conditions C section delivery cannot replace normal delivery in terms of low maternal mortality and neonatal morbidity and less cost. Prescribing antibiotics to mother of normal delivery may also be avoided if the complete sterilization process during and after the delivery is assured. [Int J Basic Clin Pharmacol 2016; 5(3.000: 794-797

  9. Polycaprolactone diacrylate crosslinked biodegradable semi-interpenetrating networks of polyacrylamide and gelatin for controlled drug delivery

    International Nuclear Information System (INIS)

    A biodegradable semi-interpenetrating hydrogel network (semi-IPN) of polyacrylamide and gelatin was prepared using polycaprolactone diacrylate (mol. wt ∼ 640) as a crosslinker. The drug-polymer interaction and IPN formation were investigated by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and thermal gravimetric analysis (TGA). Scanning electron micrographs of lyophilized matrices revealed porous internal structure with varying pore sizes under equilibrium hydrated conditions, depending upon formulation composition. pH-dependent swelling and degradation was enhanced with increasing gelatin content and decreasing crosslinker concentration (Cs). Compression modulus (CM) (at 20% strain) increased significantly from 23 ± 1.4 to 75 ± 2.7 kPa (p 0C). Fitting of drug release data in the Korsmeyer-Peppas model suggested sustained release behavior up to 10 days with a combination of diffusion and erosion mechanism (0.5 t/M∞ ≤ 0.6). The newly developed porous, biodegradable and elastic semi-IPNs may serve as an ideal matrix for controlled drug release and wound healing applications. The possibilities can be explored for pharmaceutical and tissue engineering applications.

  10. Polycaprolactone diacrylate crosslinked biodegradable semi-interpenetrating networks of polyacrylamide and gelatin for controlled drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Jaiswal, Maneesh; Koul, Veena [Centre for Biomedical Engineering, Indian Institute of Technology, New Delhi 110016 (India); Dinda, Amit K [Department of Pathology, All India Institute of Medical Sciences, New Delhi 110029 (India); Gupta, Asheesh, E-mail: veenak_iitd@yahoo.co [Department of Biochemical Pharmacology, Defense Institute of Physiology and Allied Sciences, Ministry of Defense, New Delhi 110059 (India)

    2010-12-15

    A biodegradable semi-interpenetrating hydrogel network (semi-IPN) of polyacrylamide and gelatin was prepared using polycaprolactone diacrylate (mol. wt {approx} 640) as a crosslinker. The drug-polymer interaction and IPN formation were investigated by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and thermal gravimetric analysis (TGA). Scanning electron micrographs of lyophilized matrices revealed porous internal structure with varying pore sizes under equilibrium hydrated conditions, depending upon formulation composition. pH-dependent swelling and degradation was enhanced with increasing gelatin content and decreasing crosslinker concentration (Cs). Compression modulus (CM) (at 20% strain) increased significantly from 23 {+-} 1.4 to 75 {+-} 2.7 kPa (p < 0.02) with increasing Cs (from 0.5 to 2.0 mol%), while it decreased from 162 {+-} 6.4 to 23 {+-} 1.4 kPa (p < 0.05) with decreasing PAm/G ratio. Cell viability studies by MTT assay showed excellent cytocompatibility of matrices with fibroblast L929 cells. Curcumin, a hydrophobic phytochemical, was loaded by a diffusion method and its release profile was investigated in 4% w/v aqueous BSA solution at 75 rpm (at 37 {+-} 0.2 {sup 0}C). Fitting of drug release data in the Korsmeyer-Peppas model suggested sustained release behavior up to 10 days with a combination of diffusion and erosion mechanism (0.5 < n < 1.0; M{sub t}/M{sub {infinity} {<=}} 0.6). The newly developed porous, biodegradable and elastic semi-IPNs may serve as an ideal matrix for controlled drug release and wound healing applications. The possibilities can be explored for pharmaceutical and tissue engineering applications.

  11. A novel gene delivery composite system based on biodegradable folate-poly (ester amine) polymer and thermosensitive hydrogel for sustained gene release

    Science.gov (United States)

    Yang, Yi; Zhao, Hang; Jia, Yanpeng; Guo, Qingfa; Qu, Ying; Su, Jing; Lu, Xiaoling; Zhao, Yongxiang; Qian, Zhiyong

    2016-02-01

    Local anti-oncogene delivery providing high local concentration of gene, increasing antitumor effect and decreasing systemic side effects is currently attracting interest in cancer therapy. In this paper, a novel local sustained anti-oncogene delivery system, PECE thermoresponsive hydrogel containing folate-poly (ester amine) (FA-PEA) polymer/DNA (tumor suppressor) complexes, is demonstrated. First, a tumor-targeted biodegradable folate-poly (ester amine) (FA-PEA) polymer based on low-molecular-weight polyethyleneimine (PEI) was synthesized and characterized, and the application for targeted gene delivery was investigated. The polymer had slight cytotoxicity and high transfection efficiency in vitro compared with PEI 25k, which indicated that FA-PEA was a potential vector for targeted gene delivery. Meanwhile, we successfully prepared a thermoresponsive PECE hydrogel composite containing FA-PEA/DNA complexes which could contain the genes and slowly release the genes into cells. We concluded the folate-poly (ester amine) (FA-PEA) polymer would be useful for targeted gene delivery, and the novel gene delivery composite based on biodegradable folate-poly (ester amine) polymer and thermosensitive PECE hydrogel showed potential for sustained gene release.

  12. Development and characterization of biodegradable chitosan films for local delivery of paclitaxel

    OpenAIRE

    Dhanikula, Anand Babu; Panchagnula, Ramesh

    2004-01-01

    Intratumoral and local drug delivery strategies have gained momentum recently as a promising modality in cancer therapy. In order to deliver paclitaxel at the tumor site in therapeutically relevant concentrations, chitosan films were fabricated. Paclitaxel could be loaded at 31% wt/wt in films, which were translucent and flexible. Physicochemical characterization of paclitaxel via thermal, spectroscopic, x-ray diffraction, and electron microscopy techniques revealed information on solid-state...

  13. Sustained intravitreal delivery of dexamethasone using an injectable and biodegradable thermogel.

    Science.gov (United States)

    Zhang, Li; Shen, Wenjia; Luan, Jiabin; Yang, Dongxiao; Wei, Gang; Yu, Lin; Lu, Weiyue; Ding, Jiandong

    2015-09-01

    Delivery of therapeutic agents to posterior segment of the eyes is challenging due to the anatomy and physiology of ocular barriers and thus long-acting implantable formulations are much desired. In this study, a thermogelling system composed of two poly(lactic acid-co-glycolic acid)-poly(ethylene glycol)-poly(lactic acid-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymers was developed as an injectable matrix for intravitreal drug delivery. The thermogel was prepared by mixing a sol and a precipitate of PLGA-PEG-PLGA triblock copolymers with different block ratios, among which a hydrophobic glucocorticoid, dexamethasone (DEX), was incorporated. The DEX-loaded thermogel was a low-viscous liquid at low temperature and formed a non-flowing gel at body temperature. The in vitro release rate of DEX from the thermogel could be conveniently modulated by varying the mixing ratio of the two copolymers. The long-lasting intraocular residence of the thermogel was demonstrated by intravitreal injection of a fluorescence-labeled thermogel to rabbits. Compared with a DEX suspension, the intravitreal retention time of DEX increased from a dozen hours to over 1week when being loaded in the thermogel. Additionally, intravitreal administration of the thermogel did not impair the morphology of retina and cornea. This study reveals that the injectable PLGA-PEG-PLGA thermogel is a biocompatible carrier for sustained delivery of bioactive agents into the eyes, and provides an alternative approach for treatment of posterior segment diseases. PMID:26004219

  14. Biodegradable Poly(aminoester)-Mediated p53 Gene Delivery for Cancer Therapy.

    Science.gov (United States)

    Shen, He; Liu, Min; Zhang, Zhijun

    2016-03-01

    Gene therapy is a promising strategy in cancer treatment. However, efficient gene translation still remains challenging. In the previous work, a hydrolytically degradable poly(aminoester) with good biocompatibility was synthesized. Herein, the poly(aminoester) was explored as a vector for gene delivery and cancer therapy. The experiments revealed that the poly(aminoester) condensed plasmid DNA into nanosized particles via electrostatic interaction. The pEGFP-N1 and pGL-3 were first used as two reporter genes to study intracellular transfection. The poly(aminoester) showed higher GFP expression (33%) than PEI 25 kDa (21%). Intracellular trafficking of Cy3-labelled pGL-3 also indicated that the poly(aminoester) showed superior DNA delivery ability to nucleus compared to PEI 25 kDa. Furthermore, the therapeutic gene (p53) was translated into the breast cancer cell line (MCF-7), and then induced cell apoptosis. These results suggested that the degradable poly(aminoester) is a promising and efficient gene delivery vector for gene therapeutic applications. PMID:27455620

  15. Evaluation of the functionality of biodegradable polymeric platforms for drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Gioti, M., E-mail: mgiot@physics.auth.gr; Karagkiozaki, V.; Basgiouraki, A.; Karagiannidis, P.G.; Logothetidis, S.

    2013-09-15

    We present the development of a drug-loaded triple-layer platform consisting of thin film biodegradable polymers, in a properly designed form for the desired gradual degradation. Poly(DL-lactide-co-glycolide) (PLGA (65:35), PLGA (75:25)) and polycaprolactone (PCL) were grown by spin coating technique, to synthesize the platforms with the order PCL/PLGA (75:25)/PLGA (65:35) that determine their degradation rates. The outer PLGA (65:35) layer was loaded with dipyridamole, an antiplatelet drug. Spectroscopic ellipsometry (SE) in the Vis-far UV range was used to determine the nanostructure, as well as the content of the incorporated drug in the as-grown platforms. In situ and real-time SE measurements were carried out using a liquid cell for the dynamic evaluation of the fibrinogen and albumin protein adsorption processes. Atomic force microscopy studies justified the SE results concerning the nanopores formation in the polymeric platforms, and the dominant adsorption mechanisms of the proteins, which were defined by the drug incorporation in the platforms.

  16. Evaluation of the functionality of biodegradable polymeric platforms for drug delivery systems

    Science.gov (United States)

    Gioti, M.; Karagkiozaki, V.; Basgiouraki, A.; Karagiannidis, P. G.; Logothetidis, S.

    2013-09-01

    We present the development of a drug-loaded triple-layer platform consisting of thin film biodegradable polymers, in a properly designed form for the desired gradual degradation. Poly(DL-lactide-co-glycolide) (PLGA (65:35), PLGA (75:25)) and polycaprolactone (PCL) were grown by spin coating technique, to synthesize the platforms with the order PCL/PLGA (75:25)/PLGA (65:35) that determine their degradation rates. The outer PLGA (65:35) layer was loaded with dipyridamole, an antiplatelet drug. Spectroscopic ellipsometry (SE) in the Vis-far UV range was used to determine the nanostructure, as well as the content of the incorporated drug in the as-grown platforms. In situ and real-time SE measurements were carried out using a liquid cell for the dynamic evaluation of the fibrinogen and albumin protein adsorption processes. Atomic force microscopy studies justified the SE results concerning the nanopores formation in the polymeric platforms, and the dominant adsorption mechanisms of the proteins, which were defined by the drug incorporation in the platforms.

  17. Development of bioactive glass based scaffolds for controlled antibiotic release in bone tissue engineering via biodegradable polymer layered coating

    OpenAIRE

    Nooeaid, Patcharakamon; Li, Wei; Roether, Judith A.; Mourino, Viviana; Goudouri, Ourania-Menti; Schubert, Dirk W.; Boccaccini, Aldo R.

    2014-01-01

    Highly porous 45S5 Bioglass®-based scaffolds coated with two polymer layers were fabricated to serve as a multifunctional device with controlled drug release capability for bone regeneration applications. An interior poly(D,L-lactide)/poly(ethylene glycol)-(polypropylene glycol)-poly(ethylene glycol) triblock copolymer (Pluronic P123) coating improved the mechanical stability of Bioglass-based scaffolds, while an exterior natural polymer (alginate or gelatin) coating served as an antibiotic d...

  18. Enzymatic PEGylated Poly(lactone-co-β-amino ester) Nanoparticles as Biodegradable, Biocompatible and Stable Vectors for Gene Delivery.

    Science.gov (United States)

    Chen, Ya; Li, Yingqin; Gao, Jinbiao; Cao, Zhong; Jiang, Qing; Liu, Jie; Jiang, Zhaozhong

    2016-01-13

    We have developed new, efficient gene delivery systems based on PEGylated poly(lactone-co-β-amino ester) block copolymers that are biodegradable, stable and low in toxicity. The PEG-poly[PDL-co-3-(4-(methylene)piperidin-1-yl)propanoate] (PEG-PPM) diblock and PPM-PEG-PPM triblock copolymers with various compositions were synthesized in one step via lipase-catalyzed copolymerization of ω-pentadecalactone (PDL) and ethyl 3-(4-(hydroxymethyl)piperidin-1-yl)propanoate (EHMPP) with an appropriate PEG (MeO-PEG-OH or HO-PEG-OH). The amphiphilic block copolymers are capable of condensing DNA in aqueous medium via a self-assembly process to form polyplex micelle nanoparticles with desirable particle sizes (70-140 nm). These micelles possess low CMC values and are stable in the medium containing serum protein molecules (FBS). Among the PEG-PPM and PPM-PEG-PPM micelles, the PEG-PPM-15% PDL micelle particles exhibited high DNA-binding ability, the fastest cellular uptake rate and highest gene transfection efficacy. Flow cytometry analysis shows that LucDNA/PEG-PPM-15% PDL polyplex micelles can effectively escape from endosomal degradation after cellular uptake likely due to the presence of the tertiary amine groups in the copolymer chains that act as proton sponges. In vitro cytotoxicity and hemolysis assay experiments indicate that all copolymer samples are nonhemolytic and have minimal toxicity toward COS-7 cells within the polymer concentration range (≤200 μg/mL) used for the gene transfection. These results demonstrate that the PEGylated poly(lactone-co-β-amino ester) block copolymers are promising new vectors for gene delivery applications. PMID:26673948

  19. pH-triggered drug release from biodegradable microwells for oral drug delivery

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Nagstrup, Johan; Gordon, Sarah;

    2015-01-01

    Microwells fabricated from poly-L-lactic acid (PLLA) were evaluated for their application as an oral drug delivery system using the amorphous sodium salt of furosemide (ASSF) as a model drug. Hot embossing of PLLA resulted in fabrication of microwells with an inner diameter of 240 μm and a height...... of microwell cavities with an Eudragit® layer prevented drug release in biorelevant gastric medium. An immediate release of the ASSF from coated microwells was observed in the intestinal medium. This pH-triggered release behavior demonstrates the future potential of PLLA microwells as a site-specific oral drug...

  20. Hot embossing and mechanical punching of biodegradable microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Mahshid, Rasoul; Andersen, Nis Korsgaard;

    2015-01-01

    A process has been developed to fabricate discrete three-dimensional microcontainers for oral drug delivery application in Poly-L-Lactic Acid (PLLA) polymer. The method combines hot embossing for the definition of holes in a PLLA film and mechanical punching to penetrate the polymer layer around...... the holes, after filling them with drug. Here, we demonstrate the fabrication of microcontainers with a diameter of 340 lm and a height of 50 lm. The process is temperature benign so that the compositional integrity of the drug is preserved. It also provides a good flexibility for creating different...

  1. Structured Biodegradable Polymeric Microparticles for Drug Delivery Produced Using Flow Focusing Glass Microfluidic Devices.

    Science.gov (United States)

    Ekanem, Ekanem E; Nabavi, Seyed Ali; Vladisavljević, Goran T; Gu, Sai

    2015-10-21

    Biodegradable poly(DL-lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) microparticles with tunable size, shape, internal structure and surface morphology were produced by counter-current flow focusing in axisymmetric (3D) glass capillary devices. The dispersed phase was composed of 0.5-2 wt % polymer solution in a volatile organic solvent (ethyl acetate or dichloromethane) and the continuous phase was 5 wt % aqueous poly(vinyl alcohol) solution. The droplets with a coefficient of variation in dripping regime below 2.5% were evaporated to form polymeric particles with uniform sizes ranging between 4 and 30 μm. The particle microstructure and surface roughness were modified by adding nanofiller (montmorillonite nanoclay) or porogen (2-methylpentane) in the dispersed phase to form less porous polymer matrix or porous particles with golf-ball-like dimpled surface, respectively. The presence of 2-4 wt % nanoclay in the host polymer significantly reduced the release rate of paracetamol and prevented the early burst release, as a result of reduced polymer porosity and tortuous path for the diffusing drug molecules. Numerical modeling results using the volume of fluid-continuum surface force model agreed well with experimental behavior and revealed trapping of nanoclay particles in the dispersed phase upstream of the orifice at low dispersed phase flow rates and for 4 wt % nanoclay content, due to vortex formation. Janus PLA/PCL (polycaprolactone) particles were produced by solvent evaporation-induced phase separation within organic phase droplets containing 3% (v/v) PLA/PCL (30/70 or 70/30) mixture in dichloromethane. A strong preferential adsorption of Rhodamine 6G dye onto PLA was utilized to identify PLA portions of the Janus particles by confocal laser scanning microscopy (CLSM). Uniform hemispherical PCL particles were produced by dissolution of PLA domes with acetone. PMID:26423218

  2. Biodegradable implantable fluconazole delivery rods designed for the treatment of fungal osteomyelitis: influence of gamma sterilization.

    Science.gov (United States)

    Soriano, I; Martín, A Y; Evora, C; Sánchez, E

    2006-06-01

    Fluconazole poly(D,L-lactic) acid (PLA) and poly(L-lactic) acid (L-PLA) implantable delivery rods were studied, in vitro and in vivo, as an alternative treatment of fungal osteomyelitis. Implantable rods loaded with 5% fluconazole (FLU) were prepared by the injection-molding method and sterilized by gamma-irradiation at a dose of 25 kGy. Loading efficiency, physical chemistry (high performance liquid chromatography, X-ray diffraction, gel permeation chromatography), and in vitro and in vivo release assays were performed to evaluate the novel delivery systems and the sterilization effect on implant characteristics. In spite of polymer degradation after gamma-irradiation, the loading efficiency, chemical stability, and crystallographic structure of FLU were not affected. In vivo studies were carried out in femoral bone marrow of rabbits. Approximately 85 and 80% of the total dose were released within 12 and 4 weeks from PLA and L-PLA rods, respectively. This showed a faster release rate of FLU in vivo than in vitro, showing almost zero-order kinetics from PLA rods. PMID:16514603

  3. Control of drug releasing from biodegradable polymer drug delivery system by γ-ray irradiation

    International Nuclear Information System (INIS)

    For hydrogels focussed to have a base agent for delivery system of proteins and peptides, some investigations to acquire some fundamental informations to contribute effective application of γ-ray radiation were conducted. In this fiscal year, effectiveness of hydrogellation of modified polymers with glycidyl methacrylate to overcome faults of conventional methods was investigated. By controlling modification ratio of glycidyl methacrylate as well as clarifying optimum radiation dose to stably envelope β-galactosidase by γ-ray irradiation, it was elucidated to be able to control dispersing speed of β-galactosidase. And, some informations on temperature response hydrogel changeable dispersing speed of β-galactosidase with sol-gel conversion temperature of gelatin could be obtained. (G.K.)

  4. Local delivery of biodegradable pirfenidone nanoparticles ameliorates bleomycin-induced pulmonary fibrosis in mice

    International Nuclear Information System (INIS)

    Our purpose was to assess sustained delivery and enhanced efficacy of pirfenidone-loaded nanoparticles after intratracheal instillation. Poly(lactide-co-glycolide) nanoparticles containing pirfenidone (NPs) were prepared and characterized. Biodistribution of NPs and solution was assessed using LC-MS after intratracheal administration in C57Bl/6 mice at 3 and 24 h and 1 week post-administration. Efficacy was tested in C57Bl/6 mice in a bleomycin-induced pulmonary fibrosis model. Mice received 10 μg pirfenidone intratracheally in solution or NPs, once a week, for 3 weeks after bleomycin administration. Drug effects were monitored on day 28. Lung hydroxyproline content, total number of cells, and numbers of macrophages, lymphocytes, and neutrophils in bronchoalveolar lavage (BAL) were assessed. Numbers of macrophages, lymphocytes, and neutrophils were assessed in the lung as well. NPs sustained significantly higher levels of pirfenidone in the lungs and BAL at 24 h and 1 week, compared to the solution group. Pirfenidone solution and NPs significantly reduced hydroxyproline levels by 57 and 81%, respectively, compared to bleomycin alone. At the end of 4 weeks, BAL cellularity was reduced by 25.4% and 56% with solution and NP treatment, respectively. The numbers of lymphocytes and neutrophils in the BAL were also reduced by 58.9 and 82.4% for solution and 74.5% and 89.7% for NPs, respectively. The number of inflammatory macrophages in the lung was reduced by 62.8% and the number of neutrophils was reduced by 59.1% in the NP group and by 37.7% and 44.5%, respectively, in the solution group, compared to bleomycin alone. In conclusion, nanoparticles sustain lung pirfenidone delivery and enhance its anti-fibrotic efficacy. (paper)

  5. Biodegradable mesoporous bioactive glass nanospheres for drug delivery and bone tissue regeneration

    Science.gov (United States)

    Wang, Xiaojian; Li, Wei

    2016-06-01

    Bioactive inorganic materials are attractive for hard tissue regeneration, and they are used as delivery vehicles for pharmaceutical molecules, scaffolds and components for bio-composites. We demonstrated mesoporous bioactive glass (BG) nanospheres that exhibited the capacity to deliver pharmaceutical molecules. Mesoporous BG nanospheres with variable Ca to Si ratios were synthesized using sol–gel chemistry. By controlling the hydrolysis and condensation conditions, the diameter of the mesoporous BG nanospheres was changed from 300 nm to 1500 nm. The porous structure and surface area of the BG nanospheres were shown to be dependent on their composition. The surface area of the BG nanospheres decreased from 400 ± 2 m2 g‑1 to 56 ± 0.1 m2 g‑1 when the Ca/Si ratio increased from 5 to 50 at.%. When the mesoporous BG nanospheres were loaded with ibuprofen (IBU), they exhibited a sustained release profile in simulated body fluid (SBF). In the meantime, the IBU-loaded BG nanospheres degraded in SBF, and induced apatite layer formation on the surface as a result of their good bioactivity. When the BG nanospheres were used as a composite filler to poly (ε-caprolactone) (PCL), they were shown to be effective at improving the in vitro bioactivity of PCL microspheres.

  6. Polymer hydrogel functionalized with biodegradable nanoparticles as composite system for controlled drug delivery

    International Nuclear Information System (INIS)

    The possibility to direct pharmacological treatments targeting specific cell lines using polymer nanoparticles is one of the main novelties and perspectives in nanomedicine. However, sometimes, the ability to maintain NPs localized at the site of the injection that work as a drug reservoir can represent a good and complementary option. In this direction we built a composite material made of polymeric hydrogel functionalized with polymer NPs. ϵ-caprolactone and polyethylene glycol have been copolymerized in a two-step synthesis of PEGylated NPs, while hydrogel was synthesized through polycondensation between NPs, agarose and branched polyacrylic acid. NP functionalization was verified with Fourier transform infrared spectroscopy (FTIR), high resolution magic angle spinning-nuclear magnetic resonance (HRMAS-NMR) spectroscopy and release kinetics from a hydrogel matrix and compared with NPs only physically entrapped into a hydrogel matrix. The characteristics of the resulting composite hydrogel-NPs system were studied both in terms of rheological properties and in its ability to sustain the release of To-Pro3, used as a drug mimetic compound to represent a promising drug delivery device. (paper)

  7. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery

    Directory of Open Access Journals (Sweden)

    Lee CH

    2014-01-01

    Full Text Available Cheng-Hung Lee,1,2 Yu-Huang Lin,3 Shang-Hung Chang,1 Chun-Der Tai,3 Shih-Jung Liu,2 Yen Chu,4 Chao-Jan Wang,5 Ming-Yi Hsu,5 Hung Chang,6 Gwo-Jyh Chang,7 Kuo-Chun Hung,1 Ming-Jer Hsieh,1 Fen-Chiung Lin,1 I-Chang Hsieh,1 Ming-Shien Wen,1 Yenlin Huang81Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linkou, 2Department of Mechanical Engineering, 3Graduate Institute of Medical Mechatronics, Chang Gung University, 4Laboratory of Cardiovascular Physiology, Division of Thoracic and Cardiovascular Surgery, 5Department of Medical Imaging and Intervention, 6Hematology-Oncology Division, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, 7Graduate Institute of Clinical Medicinal Sciences, Chang Gung University College of Medicine, Linkou, 8Department of Anatomical Pathology, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, TaiwanAbstract: Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a high-performance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers

  8. Nanostructure controlled sustained delivery of human growth hormone using injectable, biodegradable, pH/temperature responsive nanobiohybrid hydrogel

    Science.gov (United States)

    Singh, Narendra K.; Nguyen, Quang Vinh; Kim, Bong Sup; Lee, Doo Sung

    2015-02-01

    The clinical efficacy of a therapeutic protein, the human growth hormone (hGH), is limited by its short plasma half-life and premature degradation. To overcome this limitation, we proposed a new protein delivery system by the self-assembly and intercalation of a negatively charged hGH onto a positively charged 2D-layered double hydroxide nanoparticle (LDH). The LDH-hGH ionic complex, with an average particle size of approximately 100 nm, retards hGH diffusion. Nanobiohybrid hydrogels (PAEU/LDH-hGH) were prepared by dispersing the LDH-hGH complex into a cationic pH- and temperature-sensitive injectable PAEU copolymer hydrogel to enhance sustained hGH release by dual ionic interactions. Biodegradable copolymer hydrogels comprising poly(β-amino ester urethane) and triblock poly(ε-caprolactone-lactide)-poly(ethylene glycol)-poly-(ε-caprolactone-lactide) (PCLA-PEG-PCLA) were synthesized and characterized. hGH was self-assembled and intercalated onto layered LDH nanoparticles through an anion exchange technique. X-ray diffraction and zeta potential results showed that the LDH-hGH complex was prepared successfully and that the PAEU/LDH-hGH nanobiohybrid hydrogel had a disordered intercalated nanostructure. The biocompatibility of the nanobiohybrid hydrogel was confirmed by an in vitro cytotoxicity test. The in vivo degradation of pure PAEU and its nanobiohybrid hydrogels was investigated and it showed a controlled degradation of the PAEU/LDH nanobiohybrids compared with the pristine PAEU copolymer hydrogel. The LDH-hGH loaded injectable hydrogels suppressed the initial burst release of hGH and extended the release period for 13 days in vitro and 5 days in vivo. The developed nanohybrid hydrogel has the potential for application as a protein carrier to improve patient compliance.The clinical efficacy of a therapeutic protein, the human growth hormone (hGH), is limited by its short plasma half-life and premature degradation. To overcome this limitation, we proposed a new

  9. Biodegradable polymeric system for cisplatin delivery: Development, in vitro characterization and investigation of toxicity profile

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Noor; Khare, Vaibhav; Dubey, Ravindra; Saneja, Ankit [Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Kushwaha, Manoj; Singh, Gurdarshan; Sharma, Neelam; Chandan, Balkrishan [PK-PD-Toxicology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Gupta, Prem N., E-mail: pngupta10@gmail.com [Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India)

    2014-05-01

    Cisplatin is one of the most potent anticancer agent used in the treatment of various solid tumors, however, its clinical use is limited due to severe adverse effects including nephrotoxicity. In this investigation cisplatin loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles were developed and characterized for various in vitro characteristics including size distribution, zeta potential, drug loading and release profile. PLGA nanoparticles were successfully developed as investigated using scanning electron microscopy and exhibited average particles size and zeta potential as 284.8 nm and − 15.8 mV, respectively. Fourier transform infrared spectroscopy and differential scanning calorimetry indicated an absence of any polymer–drug interactions. Cisplatin nanoparticles exhibited in vitro anticancer activity against A549 cells comparable to that of cisplatin solution. The biodistribution study in mice indicated that the kidney cisplatin level was significantly (p < 0.01) lower with cisplatin nanoparticles than cisplatin solution. Following two cycles of cisplatin treatment, a week apart, blood urea nitrogen level was found to be higher in case of cisplatin solution as compared to cisplatin nanoparticles. Further, there was a significant (p < 0.01) increase in plasma creatinine level in case of cisplatin solution as compared to cisplatin nanoparticles. Histopathological examination of kidney from cisplatin nanoparticles treated group revealed no kidney damage, however, a sign of nephrotoxicity was observed in the case of cisplatin solution. The results suggest that PLGA nanoparticle based formulation could be a potential option for cisplatin delivery. - Highlights: • Cisplatin is detected by LCMS following complexation with DDTC. • Nanoparticles showed lower cisplatin accumulation in the kidney. • Nephrotoxicity was evaluated by BUN and creatinine level and by histopathology. • Nanoparticles exhibited lower nephrotoxicity.

  10. Co-delivery of docetaxel and endostatin by a biodegradable nanoparticle for the synergistic treatment of cervical cancer

    Science.gov (United States)

    Qiu, Bo; Ji, Minghui; Song, Xiaosong; Zhu, Yongqiang; Wang, Zhongyuan; Zhang, Xudong; Wu, Shu; Chen, Hongbo; Mei, Lin; Zheng, Yi

    2012-12-01

    Cervical cancer remains a major problem in women's health worldwide. In this research, a novel biodegradable d-α-tocopheryl polyethylene glycol 1000 succinate- b-poly(ɛ-caprolactone- ran-glycolide) (TPGS- b-(PCL- ran-PGA)) nanoparticle (NP) was developed as a co-delivery system of docetaxel and endostatin for the synergistic treatment of cervical cancer. Docetaxel-loaded TPGS- b-(PCL- ran-PGA) NPs were prepared and further modified by polyethyleneimine for coating plasmid pShuttle2-endostatin. All NPs were characterized in size, surface charge, morphology, and in vitro release of docetaxel and pDNA. The uptake of coumarin 6-loaded TPGS- b-(PCL- ran-PGA)/PEI-pDsRED by HeLa cells was observed via fluorescent microscopy and confocal laser scanning microscopy. Endostatin expression in HeLa cells transfected by TPGS- b-(PCL- ran-PGA)/PEI-pShuttle2-endostatin NPs was detected using Western blot analysis, and the cell viability of different NP-treated HeLa cells was determined by MTT assay. The HeLa cells from the tumor model, nude mice, were treated with various NPs including docetaxel-loaded-TPGS- b-(PCL- ran-PGA)/PEI-endostatin NPs, and their survival time, tumor volume and body weight were monitored during regimen process. The tumor tissue histopathology was analyzed using hematoxylin and eosin staining, and microvessel density in tumor tissue was evaluated immunohistochemically. The results showed that the TPGS- b-(PCL- ran-PGA)/PEI NPs can efficiently and simultaneously deliver both coumarin-6 and plasmids into HeLa cells, and the expression of endostatin was verified via Western blot analysis. Compared with control groups, the TPGS- b-(PCL- ran-PGA)/PEI-pShuttle2-endostatin NPs significantly decreased the cell viability of HeLa cells ( p tumors, and even eradicated the tumors. The underlying mechanism is attributed to synergistic anti-tumor effects by the combined use of docetaxel, endostatin, and TPGS released from NPs. The TPGS- b-(PCL- ran-PGA) NPs could

  11. Thermomechanical Properties, Antibiotic Release, and Bioactivity of a Sterilized Cyclodextrin Drug Delivery System

    OpenAIRE

    Halpern, Jeffrey M.; Gormley, Catherine A.; Keech, Melissa; von Recum, Horst A.

    2014-01-01

    Various local drug delivery devices and coatings are being developed as slow, sustained release mechanism for drugs, yet the polymers are typically not evaluated after commercial sterilization techniques. We examine the effect that commercial sterilization techniques have on the physical, mechanical, and drug delivery properties of polyurethane polymers. Specifically we tested cyclodextrin-hexamethyl diisocyanate crosslinked polymers before and after autoclave, ethylene oxide, and gamma radia...

  12. Biodegradable chitosan scaffolds containing microspheres as carriers for controlled transforming growth factor-β1 delivery for cartilage tissue engineering

    Institute of Scientific and Technical Information of China (English)

    CAI Dao-zhang; ZENG Chun; QUAN Da-ping; BU Li-si; WANG Kun; LU Hua-ding; LI Xiao-feng

    2007-01-01

    Background Natural articular cartilage has a limited capacity for spontaneous regeneration. Controlled release of transforming growth factor-β1 (TGF-β1) to cartilage defects can enhance chondrogenesis. In this study, we assessed the feasibility of using biodegradable chitosan microspheres as carriers for controlled TGF-β1 delivery and the effect of released TGF-β1 on the chondrogenic potential of chondrocytes.Methods Chitosan scaffolds and chitosan microspheres loaded with TGF-β1 were prepared by the freeze-drying and the emulsion-crosslinking method respectively. In vitro drug release kinetics, as measured by enzyme-linked immunosorbent assay, was monitored for 7 days. Lysozyme degradation was performed for 4 weeks to detect in vitro degradability of the scaffolds and the microspheres. Rabbit chondrocytes were seeded on the scaffolds containing TGF-β1 microspheres and incubated in vitro for 3 weeks. Histological examination and type Ⅱ collagen immunohistochemical staining was performed to evaluate the effects of released TGF-β1 on cell adhesivity, proliferation and synthesis of the extracellular matrix.Results TGF-β1 was encapsulated into chitosan microspheres and the encapsulation efficiency of TGF-β1 was high (90.1%). During 4 weeks of incubation in lysozyme solution for in vitro degradation, the mass of both the scaffolds and the microspheres decreased continuously and significant morphological changes was noticed. From the release experiments, it was found that TGF-β1 could be released from the microspheres in a multiphasic fashion including an initial burst phase, a slow linear release phase and a plateau phase. The release amount of TGF-β1 was 37.4%, 50.7%,61.3%, and 63.5% for 1, 3, 5, and 7 days respectively. At 21 days after cultivation, type Ⅱ collagen immunohistochemical staining was performed. The mean percentage of positive cells for collagen type Ⅱ in control group (32.7%± 10.4%) was significantly lower than that in the controlled

  13. The preventive role of transurethral antibiotic delivery in a rat model

    Directory of Open Access Journals (Sweden)

    Ozok HU

    2012-07-01

    Full Text Available Hakki U Ozok,1 Okan Ekim,2 Hakan Saltas,3 Ata T Arikok,4 Orkun Babacan,5 Levent Sagnak,1 Hikmet Topaloglu,1 Hamit Ersoy11Department of Urology, 3Department of Microbiology, 4Department of Pathology, Diskapi Yildirim Beyazit Training and Research Hospital, Ministry of Health, Ankara, Turkey; 2Department of Anatomy, 5Department of Microbiology, Ankara University Faculty of Veterinary Medicine, Ankara, TurkeyPurpose: There is currently an emerging need for developing improved approaches for preventing urinary tract infections (UTIs occurring during diagnostic or interventional procedures of the lower urinary tract. We aimed to establish a rat model to assess the use of transurethral antibiotic administration and to provide evidence that this could be used as a preventive therapy.Methods: Animals received fosfomycin trometamol (FOF either urethrally or orally prior to the procedure. A third group was generated as treatment controls and did not receive any medication. Urethral dilation was conducted to recapitulate an interventional procedure prior to intravesical Escherichia coli administration in all three groups. Finally, sham-operated animals were introduced as a fourth group which did not receive antibiotics or E. coli. Colony counts of urine and tissue cultures for the identification of E. coli and histopathological examinations of the bladder and prostate were conducted.Results: Evaluation of infection intensities in cultures as well as histopathological examination of the bladder and prostate demonstrated a preventative role of transurethral FOF administration. In terms of efficiency, local administration of FOF was similar to oral administration.Conclusions: These results suggest that transurethral antibiotic administration is a promising alternative for preventing UTIs occurring during diagnostic or interventional procedures of the lower urinary tract.Keywords: cystitis, fosfomycin, infection, prostatitis, urinary tract

  14. Simple and cost-effective fabrication of solid biodegradable polymer microneedle arrays with adjustable aspect ratio for transdermal drug delivery using acupuncture microneedles

    Science.gov (United States)

    Cha, Kyoung Je; Kim, Taewan; Jea Park, Sung; Kim, Dong Sung

    2014-11-01

    Polymer microneedle arrays (MNAs) have received much attention for their use in transdermal drug delivery and microneedle therapy systems due to the advantages they offer, such as low cost, good mechanical properties, and a versatile choice of materials. Here, we present a simple and cost-effective method for the fabrication of a biodegradable polymer MNA in which the aspect ratio of each microneedle is adjustable using commercially available acupuncture microneedles. In our process, a master template with acupuncture microneedles, whose shape will be the final MNA, was carefully prepared by fixing them onto a plastic substrate with selectively drilled holes which, in turn, determine the aspect ratios of the microneedles. A polylactic acid (PLA; a biodegradable polymer) MNA was fabricated by a micromolding process with a polydimethylsiloxane (PDMS) mold containing the cavity of the microneedles, which was obtained by the PDMS replica molding against the master template. The mechanical force and degradation behavior of the replicated PLA MNA were characterized with the help of a compression test and an accelerated degradation test, respectively. Finally, the transdermal drug delivery performance of the PLA MNA was successfully simulated by two different methods of penetration and staining, using the skin of a pig cadaver. These results indicated that the proposed method can be effectively used for the fabrication of polymer MNAs which can be used in various microneedle applications.

  15. Simple and cost-effective fabrication of solid biodegradable polymer microneedle arrays with adjustable aspect ratio for transdermal drug delivery using acupuncture microneedles

    International Nuclear Information System (INIS)

    Polymer microneedle arrays (MNAs) have received much attention for their use in transdermal drug delivery and microneedle therapy systems due to the advantages they offer, such as low cost, good mechanical properties, and a versatile choice of materials. Here, we present a simple and cost-effective method for the fabrication of a biodegradable polymer MNA in which the aspect ratio of each microneedle is adjustable using commercially available acupuncture microneedles. In our process, a master template with acupuncture microneedles, whose shape will be the final MNA, was carefully prepared by fixing them onto a plastic substrate with selectively drilled holes which, in turn, determine the aspect ratios of the microneedles. A polylactic acid (PLA; a biodegradable polymer) MNA was fabricated by a micromolding process with a polydimethylsiloxane (PDMS) mold containing the cavity of the microneedles, which was obtained by the PDMS replica molding against the master template. The mechanical force and degradation behavior of the replicated PLA MNA were characterized with the help of a compression test and an accelerated degradation test, respectively. Finally, the transdermal drug delivery performance of the PLA MNA was successfully simulated by two different methods of penetration and staining, using the skin of a pig cadaver. These results indicated that the proposed method can be effectively used for the fabrication of polymer MNAs which can be used in various microneedle applications. (paper)

  16. Childhood overweight after establishment of the gut microbiota: the role of delivery mode, pre-pregnancy weight and early administration of antibiotics

    DEFF Research Database (Denmark)

    Adeltoft, Teresa Ajslev; Andersen, C S; Gamborg, M;

    2011-01-01

    Objective: To investigate whether delivery mode (vaginal versus by caesarean section), maternal pre-pregnancy body mass index (BMI) and early exposure to antibiotics (<6 months of age) influence child's risk of overweight at age 7 years, hence supporting the hypotheses that environmental factors...... influencing the establishment and diversity of the gut microbiota are associated with later risk of overweight. Design: Longitudinal, prospective study with measure of exposures in infancy and follow-up at age 7 years. Methods: A total of 28¿354 mother–child dyads from the Danish National Birth Cohort, with...... information on maternal pre-pregnancy BMI, delivery mode and antibiotic administration in infancy, were assessed. Logistic regression analyses were performed with childhood height and weight at the 7-year follow-up as outcome measures. Results: Delivery mode was not significantly associated with childhood...

  17. Thermomechanical Properties, Antibiotic Release, and Bioactivity of a Sterilized Cyclodextrin Drug Delivery System.

    Science.gov (United States)

    Halpern, Jeffrey M; Gormley, Catherine A; Keech, Melissa; von Recum, Horst A

    2014-05-14

    Various local drug delivery devices and coatings are being developed as slow, sustained release mechanism for drugs, yet the polymers are typically not evaluated after commercial sterilization techniques. We examine the effect that commercial sterilization techniques have on the physical, mechanical, and drug delivery properties of polyurethane polymers. Specifically we tested cyclodextrin-hexamethyl diisocyanate crosslinked polymers before and after autoclave, ethylene oxide, and gamma radiation sterilization processes. We found that there is no significant change in the properties of polymers sterilized by ethylene oxide and gamma radiation compared to non-sterilized polymers. Polymers sterilized by autoclave showed increased tensile strength (psterilized polymers . In the release of drugs, which were loaded after the autoclave sterilization process, we observed a prolonged release (psterilized polymers. The change in the release profile and tensile strength in polymers sterilized by autoclave was interpreted as being caused by additional crosslinking from residual, unreacted, or partially-reacted crosslinker contained within the polymer. Autoclaving therefore represents additional thermo-processing to modify rate and dose from polyurethanes and other materials. PMID:24949201

  18. A biodegradable polymeric system for peptide–protein delivery assembled with porous microspheres and nanoparticles, using an adsorption/infiltration process

    Directory of Open Access Journals (Sweden)

    Alcalá-Alcalá S

    2013-06-01

    . In contrast, the systems assembled in this study released less than 44% of the loaded drug during the same period of time. The observed release profiles denoted a Fickian diffusion that fit Higuchi's model (t1/2. The manufacturing process presented here may be useful as a potential alternative for formulating injectable depots for sensitive hydrophilic drugs such as peptides and proteins, among others. Keywords: adsorption, biodegradable polymers, controlled release, nanoparticles, porous microspheres, peptide delivery

  19. Enhanced Differentiation and Delivery of Mouse Retinal Progenitor Cells Using a Micropatterned Biodegradable Thin-Film Polycaprolactone Scaffold

    OpenAIRE

    Yao, Jing; Ko, Chi Wan; Baranov, Petr Y.; Regatieri, Caio V.; Redenti, Stephen; Tucker, Budd A.; Mighty, Jason; Tao, Sarah L.; Michael J. Young

    2015-01-01

    The deterioration of retinal tissue in advanced stages of retinitis pigmentosa and age-related macular degeneration and the lack of signaling cues for laminar regeneration are significant challenges highlighting the need for a tissue engineering approach to retinal repair. In this study, we fabricated a biodegradable thin-film polycaprolactone (PCL) scaffold with varying surface topographies using microfabrication techniques. Mouse retinal progenitor cells (mRPCs) cultured on PCL scaffolds ex...

  20. Synthesis and properties of a novel biodegradable poly(ester amine copolymer based on poly(L-lactide and low molecular weight polyethylenimine for gene delivery

    Directory of Open Access Journals (Sweden)

    Guo QF

    2011-08-01

    Full Text Available Qing Fa Guo, Ting Ting Liu, Xi Yan, Xiu Hong Wang, Shuai Shi, Feng Luo, Zhi Yong QianState Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, People's Republic of ChinaBackground: Gene therapy is a promising approach to the treatment of a wide range of diseases. The development of efficient and adequate gene delivery systems could be one of the most important factors. Polyethyleneimine, a cationic polymer, is one of the most successful and widely used vectors for nonviral transfection in vitro and in vivo.Methods: A novel biodegradable poly(ester amine copolymer (PEA was successfully prepared from low molecular weight polyethylenimine (PEI, 2000 Da and poly(L-lactide copolymers.Results: According to the results of agarose gel electrophoresis, particle size and zeta potential measurement, and transfection efficiency, the PEA copolymers showed a good ability to condense plasmid DNA effectively into nanocomplexes with a small particle size (≤150 nm and moderate zeta potential (≥10 mV at an appropriate polymeric carrier/DNA weight ratio. Compared with high molecular weight PEI (25kDa, the PEA obtained showed relatively high gene transfection efficiency as well as low cytotoxicity in vitro.Conclusion: These results indicate that such PEA might have potential application as a gene delivery system.Keywords: polyethylenimine, poly(L-lactide, gene delivery, cytotoxicity, transfection efficiency

  1. Preparation of Biocompatible Carboxymethyl Chitosan Nanoparticles for Delivery of Antibiotic Drug

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2013-01-01

    Full Text Available Objective. To prepare biocompatible ciprofloxacin-loaded carboxymethyl chitosan nanoparticles (CCC NPs and evaluate their cell specificity as well as antibacterial activity against Escherichia coli in vitro. Methods. CCC NPs were prepared by ionic cross-linking method and optimized by using Box-Behnken response surface method (BBRSM. Zeta potential, drug encapsulation, and release of the obtained nanoparticles in vitro were thoroughly investigated. Minimum inhibitory concentration (MIC and killing profiles of free or ciprofloxacin-loaded nanoparticles against Escherichia coli were documented. The cytotoicity of blank nanoparticles and cellular uptake of CCC NPs were also investigated. Results. The obtained particles were monodisperse nanospheres with an average hydrated diameter of 151 ± 5.67 nm and surface of charge −22.9 ± 2.21 mV. The MICs of free ciprofloxacin and CCC NPs were 0.16 and 0.08 μg/mL, respectively. Blank nanoparticles showed no obvious cell inhibition within 24 h, and noticeable phagocytosis effect was observed in the presence of CCC NPs. Conclusion. This study shows that CCC NPs have stronger antibacterial activity against Escherichia coli than the free ciprofloxacin because they can easily be uptaken by cells. The obtained CCC NPs have promising prospect in drug delivery field.

  2. Marine Structure Derived Calcium Phosphate–Polymer Biocomposites for Local Antibiotic Delivery

    Science.gov (United States)

    Macha, Innocent J.; Cazalbou, Sophie; Ben-Nissan, Besim; Harvey, Kate L.; Milthorpe, Bruce

    2015-01-01

    Hydrothermally converted coralline hydroxyapatite (HAp) particles loaded with medically active substances were used to develop polylactic acid (PLA) thin film composites for slow drug delivery systems. The effects of HAp particles within PLA matrix on the gentamicin (GM) release and release kinetics were studied. The gentamicin release kinetics seemed to follow Power law Korsmeyer Peppas model with mainly diffusional process with a number of different drug transport mechanisms. Statistical analysis shows very significant difference on the release of gentamicin between GM containing PLA (PLAGM) and GM containing HAp microspheres within PLA matrix (PLAHApGM) devices, which PLAHApGM displays lower release rates. The use of HAp particles improved drug stabilization and higher drug encapsulation efficiency of the carrier. HAp is also the source of Ca2+ for the regeneration and repair of diseased bone tissue. The release profiles, exhibited a steady state release rate with significant antimicrobial activity against Staphylococcus aureus (S. aureus) (SH1000) even at high concentration of bacteria. The devices also indicated significant ability to control the growth of bacterial even after four weeks of drug release. Clinical release profiles can be easily tuned from drug-HAp physicochemical interactions and degradation kinetics of polymer matrix. The developed systems could be applied to prevent microbial adhesion to medical implant surfaces and to treat infections mainly caused by S. aureus in surgery. PMID:25608725

  3. Enhanced biodegradation of antibiotic combinations via the sequential treatment of the sludge resulting from pharmaceutical wastewater treatment using white-rot fungi Trametes versicolor and Bjerkandera adusta.

    Science.gov (United States)

    Aydin, Sevcan

    2016-07-01

    While anaerobic treatment is capable of treating pharmaceutical wastewater and removing antibiotics in liquid phases, solid phases may still contain significant amounts of antibiotics following this treatment. The main goal of this study was to evaluate the use of white-rot fungi to remove erythromycin, sulfamethoxazole, and tetracycline combinations from biosolids. The degradation potential of Trametes versicolor and Bjerkandera adusta was evaluated via the sequential treatment of anaerobic sludge. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses were used to identify competition between the autochthonous microbial communities and white-rot fungi. Solid-phase treatment using white-rot fungi substantially reduced antibiotic concentrations and toxicity in sludge. According to PCR-DGGE results, there is an association between species of fungus and antibiotic type as a result of the different transformation pathways of fungal strains. Fungal post-treatment of sludge represents a promising method of removing antibiotic combinations, therefore holding a significant promise as an environmentally friendly means of degrading the antibiotics present in sludge. PMID:27033714

  4. Effect of dual delivery of antibiotics (vancomycin and cefazolin) and BMP-7 from chitosan microparticles on Staphylococcus epidermidis and pre-osteoblasts in vitro.

    Science.gov (United States)

    Mantripragada, Venkata P; Jayasuriya, Ambalangodage C

    2016-10-01

    The main aims of this manuscript are to: i) determine the effect of commonly used antibiotics to treat osteoarticular infections on osteoblast viability, ii) study the dual release of the growth factor (BMP-7) and antibiotics (vancomycin and cefazolin) from chitosan microparticles iii) demonstrate the bioactivity of the antibiotics released in vitro on Staphylococcus epidermidis. The novelty of this work is dual delivery of growth factor and antibiotic from the chitosan microparticles in a controlled manner without affecting their bioactivity. Cefazolin and vancomycin have different therapeutic concentrations for their action in vivo and therefore, two different concentrations of the drugs were used. Osteoblast cytotoxicity test concluded that cefazolin concentrations of 50 and 100μg/ml were found to have positive influence on osteoblast proliferation. A significant increase in osteoblast proliferation was observed in the presence of cefazolin and BMP-7 in comparison with BMP-7 alone group; indicating cefazolin might play a role in osteoblast proliferation. On the other hand, vancomycin concentration of 1000μg/ml was found to significantly reduce (p<0.01) osteoblast proliferation in comparison with controls. The microbial study indicated that cefazolin at a minimum concentration of 21.5μg/ml could inhibit ~85% growth of S. epidermidis, whereas vancomycin at a concentration of 30μg/ml was found to inhibit ~80% bacterial growth. PMID:27287137

  5. Biodegradable cationic polymeric nanocapsules for overcoming multidrug resistance and enabling drug-gene co-delivery to cancer cells

    Science.gov (United States)

    Chen, Chih-Kuang; Law, Wing-Cheung; Aalinkeel, Ravikumar; Yu, Yun; Nair, Bindukumar; Wu, Jincheng; Mahajan, Supriya; Reynolds, Jessica L.; Li, Yukun; Lai, Cheng Kee; Tzanakakis, Emmanuel S.; Schwartz, Stanley A.; Prasad, Paras N.; Cheng, Chong

    2014-01-01

    Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both agents can be readily taken up by PC3 prostate cancer cells, resulting in a significant chemotherapeutic effect and/or IL-8 gene silencing.Having unique architectural features, cationic polymeric nanocapsules (NCs) with well-defined covalently stabilized biodegradable structures were generated as potentially universal and safe therapeutic nanocarriers. These NCs were synthesized from allyl-functionalized cationic polylactide (CPLA) by highly efficient UV-induced thiol-ene interfacial cross-linking in transparent miniemulsions. With tunable nanoscopic sizes, negligible cytotoxicity and remarkable degradability, they are able to encapsulate doxorubicin (Dox) with inner cavities and bind interleukin-8 (IL-8) small interfering RNA (siRNA) with cationic shells. The Dox-encapsulated NCs can effectively bypass the P-glycoprotein (Pgp)-mediated multidrug resistance of MCF7/ADR cancer cells, thereby resulting in increased intracellular drug concentration and reduced cell viability. In vitro studies also showed that the NCs loaded with Dox, IL-8 siRNA and both

  6. Size-controlled synthesis of biodegradable nanocarriers for targeted and controlled cancer drug delivery using salting out cation

    Indian Academy of Sciences (India)

    Madasamy Hari Balakrishanan; Mariappan Rajan

    2016-02-01

    Research for synthesis of size-controlled carriers is currently challenging one. In this research paper, a method for size-controlled synthesis of biodegradable nanocarriers is proposed and described. Salting out method is suitable for both hydrophilic and hydrophobic drugs for the encapsulation on carriers. This synthetic method is based on polylactic acid (PLA) and non-ionic carboxymethyl cellulose (CMC) composed by CaCl2 as salting out agent. This method permits size-controlled synthesis of particles between 50 and 400 nm simply by varying the concentration of salting out agents. We have prepared cisplatin (CDDP)-loaded PLA-CMC nanocarriers by salting out method, with varying salting out agent (CaCl2) concentrations as 0.05, 0.2, 0.35 and 0.5 M. The nanocarriers were characterized for their size, surface charge and morphology by atomic force microscope, zeta potential analyser and transmission electron microscope, respectively. The encapsulation efficiency and in-vitro drug-releasing behaviour of the nanocarriers were investigated. The cytotoxicity effect of nanocarriers and drug-loaded nanocarriers was tested against MCF-7 breast cancer cell line.

  7. Synthesis and characterization of biodegradable poly(ethylene glycol)-block-poly(5-benzyloxy-trimethylene carbonate) copolymers for drug delivery.

    Science.gov (United States)

    Zeng, Faquan; Liu, Jubo; Allen, Christine

    2004-01-01

    Amphiphilic diblock copolymers with various block compositions were synthesized with monomethoxy-terminated poly(ethylene glycol) (MePEG) as the hydrophilic block and poly(5-benzyloxy-trimethylene carbonate) (PBTMC) as the hydrophobic block. When the copolymerization was conducted using MePEG as a macroinitiator and stannous 2-ethylhexanoate (Sn(Oct)2) as a catalyst, the molecular weight of the second block was uncontrollable, and the method only afforded a mixture of homopolymer and copolymer with a broad molecular weight distribution. By contrast, the use of the triethylaluminum-MePEG initiator yielded block copolymers with controllable molecular weight and a more narrow molecular weight distribution than the copolymers obtained using Sn(Oct)2. GPC and 1H NMR studies confirmed that the macroinitiator was consumed and the copolymer composition was as predicted. Two of the newly synthesized MePEG-b-PBTMC copolymers were evaluated in terms of properties primarily relating to their use in micellar drug delivery. MePEG-b-PBTMC micelles with a narrow monomodal size distribution were prepared using a high-pressure extrusion technique. The MePEG-b-PBTMC copolymers were also confirmed to be biodegradable and noncytotoxic. PMID:15360292

  8. Acute toxicity evaluation of in situ gel-forming controlled drug delivery system based on biodegradable poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Fang Fang; Gong Changyang; Dong Pengwei; Fu Shaozhi; Gu Yingchun; Guo Gang; Zhao Xia; Wei Yuquan; Qian Zhiyong, E-mail: anderson-qian@163.co, E-mail: zhiyongqian@scu.edu.c [State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, 610041 (China)

    2009-04-15

    In this paper, biodegradable poly(epsilon-caprolactone)-poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) triblock copolymer was synthesized, and was characterized by FTIR, {sup 1}H-NMR and GPC. The PCL-PEG-PCL/dimethyl sulfoxide (DMSO) solution displayed in situ gelling behavior when subcutaneously injected into the body. Toxicity tests and a histopathological study were performed in BALB/c mice. We focused mainly on acute organ toxicity of BALB/c mice by subcutaneous injection. In the acute toxicity test, the dose of subcutaneous injection was 5 g/kg body weight (b.w.), and the mice were observed continuously for 14 days. For the histopathological study, samples including heart, lung, liver, kidneys, spleen, stomach and intestine were histochemically prepared and stained with hematoxylin-eosin for histopathological examination. No mortality or significant signs of toxicity were observed during the whole observation period, and there is no significant lesion to be shown in histopathological study of major organs in the mice. Therefore, the maximal tolerance dose of dimethyl sulfoxide (DMSO) solution of PCL-PEG-PCL copolymer by subcutaneous injection was calculated to be higher than 5 g/kg b.w. Therefore, the PCL-PEG-PCL/DMSO system was thought to be non-toxic after subcutaneous injection, and it might be a candidate for an in situ gelling controlled drug delivery system.

  9. Biodegradable self-assembled PEG-PCL-PEG micelles for hydrophobic honokiol delivery: I. Preparation and characterization

    International Nuclear Information System (INIS)

    This study aims to develop self-assembled poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) micelles to encapsulate hydrophobic honokiol (HK) in order to overcome its poor water solubility and to meet the requirement of intravenous administration. Honokiol loaded micelles (HK-micelles) were prepared by self-assembly of PECE copolymer in aqueous solution, triggered by its amphiphilic characteristic assisted by ultrasonication without any organic solvents, surfactants and vigorous stirring. The particle size of the prepared HK-micelles measured by Malvern laser particle size analyzer were 58 nm, which is small enough to be a candidate for an intravenous drug delivery system. Furthermore, the HK-micelles could be lyophilized into powder without any adjuvant, and the re-dissolved HK-micelles are stable and homogeneous with particle size about 61 nm. Furthermore, the in vitro release profile showed a significant difference between the rapid release of free HK and the much slower and sustained release of HK-micelles. Moreover, the cytotoxicity results of blank micelles and HK-micelles showed that the PECE micelle was a safe carrier and the encapsulated HK retained its potent antitumor effect. In short, the HK-micelles were successfully prepared by an improved method and might be promising carriers for intravenous delivery of HK in cancer chemotherapy, being effective, stable, safe (organic solvent and surfactant free), and easy to produce and scale up.

  10. Biodegradable PLGA85/15 nanoparticles as a delivery vehicle for Chlamydia trachomatis recombinant MOMP-187 peptide

    International Nuclear Information System (INIS)

    Development of a Chlamydia trachomatis vaccine has been a formidable task partly because of an ineffective delivery system. Our laboratory has generated a recombinant peptide of C. trachomatis major outer membrane protein (MOMP) (rMOMP-187) and demonstrated that it induced at 20 μg ml−1 maximal interleukin (IL)-6 and IL-12p40 Th1 cytokines in mouse J774 macrophages. In a continuous pursuit of a C. trachomatis effective vaccine-delivery system, we encapsulated rMOMP-187 in poly(d,l-lactic-co-glycolic acid) (PLGA, 85:15 PLA/PGA ratio) to serve as a nanovaccine candidate. Physiochemical characterizations were assessed by Fourier transform-infrared spectroscopy, atomic force microscopy, Zetasizer, Zeta potential, transmission electron microcopy and differential scanning calorimetry. The encapsulated rMOMP-187 was small (∼200 nm) with an apparently smooth uniform oval structure, thermally stable (54 °C), negatively charged ( − 27.00 mV) and exhibited minimal toxicity at concentrations −1 to eukaryotic cells (>95% viable cells) over a 24–72 h period. We achieved a high encapsulation efficiency of rMOMP-187 (∼98%) in PLGA, a loading peptide capacity of 2.7% and a slow release of the encapsulated peptide. Stimulation of J774 macrophages with a concentration as low as 1 μg ml −1 of encapsulated rMOMP-187 evoked high production levels of the Th1 cytokines IL-6 (874 pg ml−1) and IL-12p40 (674 pg ml−1) as well as nitric oxide (8 μM) at 24 h post-stimulation, and in a dose-response and time-kinetics manner. Our data indicate the successful encapsulation and characterization of rMOMP-187 in PLGA and, more importantly, that PLGA enhanced the capacity of the peptide to induce Th1 cytokines and NO in vitro. These findings make this nanovaccine an attractive candidate in pursuit of an efficacious vaccine against C. trachomatis. (paper)

  11. Biodegradable PLGA85/15 nanoparticles as a delivery vehicle for Chlamydia trachomatis recombinant MOMP-187 peptide

    Science.gov (United States)

    Taha, Murtada A.; Singh, Shree R.; Dennis, Vida A.

    2012-08-01

    Development of a Chlamydia trachomatis vaccine has been a formidable task partly because of an ineffective delivery system. Our laboratory has generated a recombinant peptide of C. trachomatis major outer membrane protein (MOMP) (rMOMP-187) and demonstrated that it induced at 20 μg ml-1 maximal interleukin (IL)-6 and IL-12p40 Th1 cytokines in mouse J774 macrophages. In a continuous pursuit of a C. trachomatis effective vaccine-delivery system, we encapsulated rMOMP-187 in poly(d,l-lactic-co-glycolic acid) (PLGA, 85:15 PLA/PGA ratio) to serve as a nanovaccine candidate. Physiochemical characterizations were assessed by Fourier transform-infrared spectroscopy, atomic force microscopy, Zetasizer, Zeta potential, transmission electron microcopy and differential scanning calorimetry. The encapsulated rMOMP-187 was small (˜200 nm) with an apparently smooth uniform oval structure, thermally stable (54 °C), negatively charged ( - 27.00 mV) and exhibited minimal toxicity at concentrations 95% viable cells) over a 24-72 h period. We achieved a high encapsulation efficiency of rMOMP-187 (˜98%) in PLGA, a loading peptide capacity of 2.7% and a slow release of the encapsulated peptide. Stimulation of J774 macrophages with a concentration as low as 1 μg ml -1 of encapsulated rMOMP-187 evoked high production levels of the Th1 cytokines IL-6 (874 pg ml-1) and IL-12p40 (674 pg ml-1) as well as nitric oxide (8 μM) at 24 h post-stimulation, and in a dose-response and time-kinetics manner. Our data indicate the successful encapsulation and characterization of rMOMP-187 in PLGA and, more importantly, that PLGA enhanced the capacity of the peptide to induce Th1 cytokines and NO in vitro. These findings make this nanovaccine an attractive candidate in pursuit of an efficacious vaccine against C. trachomatis.

  12. Stimuli-responsive protamine-based biodegradable nanocapsules for enhanced bioavailability and intracellular delivery of anticancer agents

    International Nuclear Information System (INIS)

    Enzyme- and pH-responsive polyelectrolyte nanocapsules having diameters in the range of 200 ± 20 nm were fabricated by means of Layer-by-Layer assembly of biopolymers, protamine, and heparin, and then loaded with anticancer drug doxorubicin. The incorporation of the FDA-approved peptide drug protamine as a wall component rendered the capsules responsive to enzyme stimuli. The stimuli-responsive drug release from these nanocapsules was evaluated, and further modulation of capsule permeability to avoid premature release was demonstrated by crosslinking the wall components. The interaction of the nanocapsules with cancer cells was studied using MCF-7 breast cancer cells. These capsules were readily internalized and disintegrated inside the cells, culminating in the release of the loaded doxorubicin and subsequent cell death as observed by confocal microscopy and MTT Assay. The bioavailability studies performed using BALB/c mice revealed that the encapsulated doxorubicin exhibited enhanced bioavailability compared to free doxorubicin. Our results indicate that this stimuli-responsive system fabricated from clinically used FDA-approved molecules and exhibiting minimal premature release has great potential for drug-delivery applications.

  13. Stimuli-responsive protamine-based biodegradable nanocapsules for enhanced bioavailability and intracellular delivery of anticancer agents

    Energy Technology Data Exchange (ETDEWEB)

    Radhakrishnan, Krishna; Thomas, Midhun B.; Pulakkat, Sreeranjini [Indian Institute of Science, Department of Materials Engineering (India); Gnanadhas, Divya P.; Chakravortty, Dipshikha [Indian Institute of Science, Department of Microbiology and Cell Biology (India); Raichur, Ashok M., E-mail: amr@materials.iisc.ernet.in [Indian Institute of Science, Department of Materials Engineering (India)

    2015-08-15

    Enzyme- and pH-responsive polyelectrolyte nanocapsules having diameters in the range of 200 ± 20 nm were fabricated by means of Layer-by-Layer assembly of biopolymers, protamine, and heparin, and then loaded with anticancer drug doxorubicin. The incorporation of the FDA-approved peptide drug protamine as a wall component rendered the capsules responsive to enzyme stimuli. The stimuli-responsive drug release from these nanocapsules was evaluated, and further modulation of capsule permeability to avoid premature release was demonstrated by crosslinking the wall components. The interaction of the nanocapsules with cancer cells was studied using MCF-7 breast cancer cells. These capsules were readily internalized and disintegrated inside the cells, culminating in the release of the loaded doxorubicin and subsequent cell death as observed by confocal microscopy and MTT Assay. The bioavailability studies performed using BALB/c mice revealed that the encapsulated doxorubicin exhibited enhanced bioavailability compared to free doxorubicin. Our results indicate that this stimuli-responsive system fabricated from clinically used FDA-approved molecules and exhibiting minimal premature release has great potential for drug-delivery applications.

  14. Utilization of bio-degradable fermented tapioca to synthesized low toxicity of carbon nanotubes for drug delivery applications

    Science.gov (United States)

    Nurulhuda, I.; Poh, R.; Mazatulikhma, M. Z.; Salman, A. H. A.; Haseeb, A. K.; Rusop, M.

    2016-07-01

    Carbon nanotubes (CNT) have potential biomedical applications, and investigations are shifting towards the production of such nanotubes using renewable natural sources. CNTs were synthesized at various temperatures of 700, 750, 800, 850 and 900 °C, respectively, using a local fermented food known as "tapai ubi" or fermented tapioca as a precursor. The liquid part of this fermented food was heated separately at 80°C and channeled directly into the furnace system that employs the thermal chemical vapor deposition (CVD) method. Ferrocene, which was the catalyst was placed in furnace 1 in the thermal CVD process. The resulting CNTs produced from the process were studied using field emission scanning electron microscopy (FESEM) and raman spectroscopy. The FESEM images showed the growth morphology of the CNTs at the different temperatures employed. It was observed that the higher the synthesis temperature up to a point, the diameter of CNTs produced, after which the diameter increased. CNTs with helical structures were observed at 700 °C with a diameter range of 111 - 143 nm. A more straightened structure was observed at 750 °C with a diameter range of 59 - 121 nm. From 800 °C onwards, the diameters of the CNTs were less than 60 nm. Raman analysis revealed the present of D, G and G' peak were observed at 1227-1358, 1565-1582, and 2678-2695 cm-1, respectively. The highest degree of crystallity of the carbon nanotubes synthesized were obtained at 800 °C. The radial breathing mode (RBM) were in range between 212-220 and 279-292 cm-1. Carbon nanotubes also being functionalized with Polyethylene bis(amine) Mw2000 (PEG 2000-NH2) and showed highly cells viability compared to non-functionalized CNT. The nanotubes synthesized will be applied as drug delivery in future study.

  15. Biodegradable Polymers

    OpenAIRE

    Isabelle Vroman; Lan Tighzert

    2013-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  16. Biodegradable self-assembled PEG-PCL-PEG micelles for hydrophobic drug delivery, part 2: in vitro and in vivo toxicity evaluation

    International Nuclear Information System (INIS)

    Polymeric micelles, prepared by self-assembly of biodegradable poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG–PCL–PEG, PECE) copolymer in aqueous solution, were proved to be a potential carrier for hydrophobic drug honokiol in our previous contribution. In this study, the safety of blank PECE micelles was evaluated in vitro and in vivo before its further application in biomedical field. The average particle size of obtained micelle was 83.47 ± 0.44 nm, and polydisperse index was 0.27 ± 0.01. Also, the zeta potential of prepared micelles was about −0.41 ± 0.02 mV. Otherwise, cytotoxicity of PECE micelles was evaluated by cell viability assay using L929 cells, and in vitro hemolytic test was also performed. In vivo acute toxicity evaluation and histopathological study of PECE micelles were conducted in BALB/c mice by intravenous administration. Furthermore, serum chemistry profile and complete blood count test were performed. In acute toxicity test, the mice were observed continuously for 7 days. For histopathological study, samples including heart, liver, spleen, lung, and kidneys were histochemical prepared and stained with hematoxylin-eosin (H and E). No mortality or significant signs of acute toxicity was observed during the whole observation period, and there is no significant lesion to be shown in histopathological study of major organs. The maximal tolerance dose of PECE micelles (100 mg/mL) by intravenous administration was calculated to be higher than 10 g/kg body weight (b.w.). The results indicated that the obtained PECE micelles was non-toxic after intravenous administration, and could be a safe candidate for hydrophobic drug delivery system.

  17. Critical evaluation of biodegradable polymers used in nanodrugs.

    Science.gov (United States)

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  18. Biodegradation of Phosphonomycin by Rhizobium huakuii PMY1

    OpenAIRE

    McGrath, John W.; Hammerschmidt, Friedrich; Quinn, John P.

    1998-01-01

    The biodegradation by Rhizobium huakuii PMY1 of up to 10 mM phosphonomycin as a carbon, energy, and phosphorus source with accompanying Pi release is described. This biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by Rhizobium spp.

  19. A biodegradable polymeric system for peptide–protein delivery assembled with porous microspheres and nanoparticles, using an adsorption/infiltration process

    OpenAIRE

    Alcala, Sergio

    2013-01-01

    Sergio Alcalá-Alcalá, Zaida Urbán-Morlán, Irene Aguilar-Rosas, David Quintanar-Guerrero Laboratorio de Investigación y Posgrado en Tecnología Farmacéutica, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Estado de México, México Abstract: A biodegradable polymeric system is proposed for formulat...

  20. Antibiotics Quiz

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  1. Biodegradable micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Greve, Anders; Schmid, Silvan;

    The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization of mechani......The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization...... of biopolymers to microfabrication is challenging, as these polymers are affected by common processes such as photolithography or wet etching. Here, we present two methods for fabrication of biodegradable micromechanical sensors. First, we fabricated bulk biopolymer microcantilevers using nanoimprint lithography...

  2. Critical evaluation of biodegradable polymers used in nanodrugs

    Directory of Open Access Journals (Sweden)

    Marin E

    2013-08-01

    Full Text Available Edgar Marin,1–3 Maria Isabel Briceño,2 Catherina Caballero-George11Unit of Pharmacology, Center of Biodiversity and Drug Discovery, Institute of Scientific Research and High Technology Services, 2Nano Dispersions Technology, Panama, Republic of Panama; 3Department of Biotechnology, Archaria Nagarjuna University, Guntur, IndiaAbstract: Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.Keywords: biodegradable polymers, nanoparticles, drug delivery, cellular uptake, biomedical applications

  3. Self-assembly of biodegradable copolyester and reactive HPMA-based polymers into nanoparticles as an alternative stealth drug delivery system

    Czech Academy of Sciences Publication Activity Database

    Jäger, Eliezer; Jäger, Alessandro; Etrych, Tomáš; Giacomelli, F. C.; Chytil, Petr; Jigounov, Alexander; Putaux, J.-L.; Říhová, Blanka; Ulbrich, Karel; Štěpánek, Petr

    2012-01-01

    Roč. 8, č. 37 (2012), s. 9563-9575. ISSN 1744-683X R&D Projects: GA AV ČR IAAX00500803; GA ČR GAP208/10/1600 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50200510 Institutional support: RVO:61389013 ; RVO:61388971 Keywords : biodegradable nanoparticles * light scattering from polymer nanoparticles * doxorubicin drug release Subject RIV: CF - Physical ; Theoretical Chemistry; EC - Immunology (MBU-M) Impact factor: 3.909, year: 2012

  4. A biodegradable polymeric system for peptide–protein delivery assembled with porous microspheres and nanoparticles, using an adsorption/infiltration process

    OpenAIRE

    Alcalá-Alcalá S; Urbán-Morlán Z; Aguilar-Rosas I; Quintanar-Guerrero D

    2013-01-01

    Sergio Alcalá-Alcalá, Zaida Urbán-Morlán, Irene Aguilar-Rosas, David Quintanar-Guerrero Laboratorio de Investigación y Posgrado en Tecnología Farmacéutica, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Estado de México, México Abstract: A biodegradable polymeric system is proposed for formulating peptides and proteins. The systems were assembled...

  5. Antibiotic Resistance

    Science.gov (United States)

    Antibiotics are medicines that fight bacterial infections. Used properly, they can save lives. But there is a growing problem of antibiotic resistance. It happens when bacteria change and become able to resist the effects of an antibiotic. Using antibiotics can lead to resistance. ...

  6. Biodegradable In Situ Gel-Forming Controlled Drug Delivery System Based on Thermosensitive Poly(ε-caprolactone)-Poly(ethylene glycol)-Poly(ε-caprolactone) Hydrogel

    OpenAIRE

    Elham Khodaverdi; Ali Golmohammadian; Seyed Ahmad Mohajeri; Gholamhossein Zohuri; Farnaz Sadat Mirzazadeh Tekie; Farzin Hadizadeh

    2012-01-01

    Traditional drug delivery systems which are based on multiple dosing regimens usually pose many disadvantages such as poor compliance of patients and drug plasma level variation. To overcome the obstacles of traditional drug formulations, novel drug delivery system PCL-PEG-PCL hydrogels have been purposed in this study. Copolymers were synthesized by rapid microwave-assisted and conventional synthesis methods. Polymer characterizations were done using gel permeation chromatography and 1H-NMR....

  7. A novel enzymatically-mediated drug delivery carrier for bone tissue engineering applications: combining biodegradable starch-based microparticles and differentiation agents

    OpenAIRE

    Balmayor, Elizabeth Rosado; Tuzlakoglu, K.; Marques, A.P.; Azevedo, Helena S.; Reis, R.L.

    2008-01-01

    In many biomedical applications, the performance of biomaterials depends largely on their degradation behavior. For instance, in drug delivery applications, the polymeric carrier should degrade under physiological conditions slowly releasing the encapsulated drug. The aim of this work was, therefore, to develop an enzymaticmediated degradation carrier system for the delivery of differentiation agents to be used in bone tissue engineering applications. For that, a polym...

  8. Assessment of anaerobic bacterial diversity and its effects on anaerobic system stability and the occurrence of antibiotic resistance genes.

    Science.gov (United States)

    Aydin, Sevcan; Ince, Bahar; Ince, Orhan

    2016-05-01

    This study evaluated the link between anaerobic bacterial diversity and, the biodegradation of antibiotic combinations and assessed how amending antibiotic combination and increasing concentration of antibiotics in a stepwise fashion influences the development of resistance genes in anaerobic reactors. The biodegradation, sorption and occurrence of the known antibiotic resistance genes (ARGs) of erythromycin and tetracycline were investigated using the processes of UV-HPLC and qPCR analysis respectively. Ion Torrent sequencing was used to detect microbial community changes in response to the addition of antibiotics. The overall results indicated that changes in the structure of a microbial community lead to changes in biodegradation capacity, sorption of antibiotics combinations and occurrence of ARGs. The enhanced biodegradation efficiency appeared to generate variations in the structure of the bacterial community. The results suggested that controlling the ultimate Gram-negative bacterial community, especially Acinetobacter-related populations, may promote the successful biodegradation of antibiotic combinations and reduce the occurrence of ARGs. PMID:26897411

  9. Biodegradable nanoparticles for gene therapy technology

    International Nuclear Information System (INIS)

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes

  10. Biodegradable nanoparticles for gene therapy technology

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinkhani, Hossein, E-mail: hosseinkhani@mail.ntust.edu.tw; He, Wen-Jie [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Chiang, Chiao-Hsi [School of Pharmacy, National Defense Medical Center (China); Hong, Po-Da [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Yu, Dah-Shyong [Nanomedicine Research Center, National Defense Medical Center (China); Domb, Abraham J. [The Hebrew University of Jerusalem, Institute of Drug Research, School of Pharmacy, Faculty of Medicine, Center for Nanoscience and Nanotechnology and The Alex Grass Center for Drug Design and Synthesis (Israel); Ou, Keng-Liang [College of Oral Medicine, Taipei Medical University, Research Center for Biomedical Devices and Prototyping Production (China)

    2013-07-15

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

  11. Development and evaluation of biodegradable microspheres embedded in in situ gel for controlled delivery of hydrophilic drug for treating oral infections: In vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Neha Manish Munot

    2014-01-01

    Full Text Available Present investigation was aimed at developing biodegradable polymeric microspheres of Tetracycline hydrochloride to treat oral infections by using Poly (D, L lactic-co-glycolic acid (50:50 as polymer. Microspheres were prepared using oil-in-oil (O/O and water-in-oil-in-water (W/O/W double emulsion solvent evaporation method. Microspheres prepared by W/O/W were spherical in shape compared those prepared with O/O method. Thus, the microspheres formulated by W/O/W method were further evaluated for particle size, morphology, entrapment efficiency, and percent drug release. Effects of salt addition, polymer concentration on the characteristics of microspheres and tetracycline release profile were investigated. An increase in polymer concentration decreased drug release and increased entrapment efficiency of drug. In vitro studies indicated that release of drug from microspheres could be controlled for 10-15 days depending on drug: Polymer concentration. Formulation E released 99.10% of drug from microspheres in 10 days. Addition of sodium chloride to outer aqueous phase produced spherical microspheres with smooth surface and also increased entrapment efficiency. Microspheres were further dispersed in optimized formulation of mucoadhesive in situ gel of Pluronic F127, which acts as carrier for microspheres. In vivo studies were conducted on patients who underwent molar tooth extraction to check efficacy of designed formulation.

  12. Compliance of vaginal delivery puerpera for antibiotic prophylaxis%阴道分娩产妇对预防性应用抗菌药物的依从性调查

    Institute of Scientific and Technical Information of China (English)

    白灵波

    2012-01-01

    目的 了解阴道分娩产妇对会阴切口预防性应用抗菌药物的依从性,以期促进抗菌药物的合理使用.方法 选择医院正常阴道分娩有会阴切口的产妇共2000例为研究对象,以问卷形式调查其在产后对应用抗菌药物的依从性,包括是否接受使用抗菌药物、选择药物的种类、用药途径、用药时间及用药费用等.结果 产妇接受抗菌药物者1686例占84.3%,其中1258例占62.9%接受口服头孢类药物,404例占20.2%要求静脉用药,用药时间2~3 d,80.0%不计较用药费用;15.7%的产妇不接受抗菌药物,其中112例,占5.6%认为药物对哺乳有不良影响.结论 产妇对会阴切口预防性应用抗菌药物的依从性方面存在误区,需要开展有效的合理用药宣传教育,合理使用抗菌药物,避免不必要的医疗开支.%OBJECTIVE To improve the compliance of preventive application of antibiotics for perineum of vaginal delivery with perineum incision so that it can promote the rational use of antibiotics. METHODS The puerpera with normal perineum incision 2000 cases were researched and their compliance of application antibiotics to prevent infections was investigated by using questionnaire. The questions included the following aspects: whether or.not to accept the application of antibiotics, select the type of medicine, route, time and costs of administrating medicine, and so on. RESULTS There were 1686 puerpera accepting antibiotics (accounting for 84. 3%). There were 1258 cases accepting antibiotics (62. 9%) by oral and 404 cases by intravenous among these puerpera. The duration of using antibiotics was 2 to 3 days and they (80%) did not worry the costs. There were 404 puerpera without accepting antibiotics (20. 2%). They( 112 cases) were afraid that medicine had an adverse effect on lactation among 404 puerpera. CONCLUSION There exists the error on the aspect of compliance of prophylactic use of antibiotics for perineum incision, it

  13. Proceedings of biodegradation

    International Nuclear Information System (INIS)

    This book contains the proceedings of Biodegradation. Topics include:biodegradation using the tools of biotechnology, basic science aspects of biodegradation, the physiological characteristics of microorganisms, the use of selective techniques that enhance the process of microbial evolution of biodegradative genes in nature, the genetic characteristics of microorganisms allowing them to biodegrade both natural and synthetic toxic chemicals, the molecular techniques that allow selective assembly of genetic segments form a variety of bacterial strains to a single strain, and methods needed to advance biodegradation research as well as the high-priority chemical problems important to the Department of Defense or to the chemical industry

  14. Biodegradable PEG-based drug carriers

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Braunová, Alena; Ulbrich, Karel; Jelínková, Markéta; Říhová, Blanka; Seymour, L. W.

    Glasgow : University of Strathclyde, 2005, s. 7-9. [Conference on New Approaches to Drug Delivery "Nanomedicines of the Future". Glasgow (GB), 18.11.2005] R&D Projects: GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable polymers * drug carriers Subject RIV: EI - Biotechnology ; Bionics

  15. Nanoparticle-based delivery of efflux pump inhibitors and antibiotics to treat mycobacterial infections. Reducing thioridazine toxicity to potentiate antituberculosis therapy

    OpenAIRE

    Vibe, Carina Beatrice

    2014-01-01

    Tuberculosis (TB), caused by Mycobacterium tuberculosis, has been treated with the same arsenal of antibiotics since the 1970 s; and with an estimated one third of the world s population latently infected at the moment, new regimens are sorely needed. Treatment remains lengthy and difficult, and inappropriate dosing or administration of drugs as well as patient non-compliance is contributing to the rising threat of multi-, extensively- and now totally- drug resistant TB. Should further expans...

  16. Biodegradable Eri silk nanoparticles as a delivery vehicle for bovine lactoferrin against MDA-MB-231 and MCF-7 breast cancer cells.

    Science.gov (United States)

    Roy, Kislay; Patel, Yogesh S; Kanwar, Rupinder K; Rajkhowa, Rangam; Wang, Xungai; Kanwar, Jagat R

    2016-01-01

    This study used the Eri silk nanoparticles (NPs) for delivering apo-bovine lactoferrin (Apo-bLf) (~2% iron saturated) and Fe-bLf (100% iron saturated) in MDA-MB-231 and MCF-7 breast cancer cell lines. Apo-bLf and Fe-bLf-loaded Eri silk NPs with sizes between 200 and 300 nm (±10 nm) showed a significant internalization within 4 hours in MDA-MB-231 cells when compared to MCF-7 cells. The ex vivo loop assay with chitosan-coated Fe-bLf-loaded silk NPs was able to substantiate its future use in oral administration and showed the maximum absorption within 24 hours by ileum. Both Apo-bLf and Fe-bLf induced increase in expression of low-density lipoprotein receptor-related protein 1 and lactoferrin receptor in epidermal growth factor (EGFR)-positive MDA-MB-231 cells, while transferrin receptor (TfR) and TfR2 in MCF-7 cells facilitated the receptor-mediated endocytosis of NPs. Controlled and sustained release of both bLf from silk NPs was shown to induce more cancer-specific cytotoxicity in MDA-MB-231 and MCF-7 cells compared to normal MCF-10A cells. Due to higher degree of internalization, the extent of cytotoxicity and apoptosis was significantly higher in MDA-MB-231 (EGFR+) cells when compared to MCF-7 (EGFR-) cells. The expression of a prominent anticancer target, survivin, was found to be downregulated at both gene and protein levels. Taken together, all the observations suggest the potential use of Eri silk NPs as a delivery vehicle for an anti-cancer milk protein, and indicate bLf for the treatment of breast cancer. PMID:26730188

  17. Self-Assembled Cationic Biodegradable Nanoparticles from pH-Responsive Amino-Acid-Based Poly(Ester Urea Urethane)s and Their Application As a Drug Delivery Vehicle.

    Science.gov (United States)

    He, Mingyu; Potuck, Alicia; Kohn, Julie C; Fung, Katharina; Reinhart-King, Cynthia A; Chu, Chih-Chang

    2016-02-01

    The objective of this study is to develop a new family of biodegradable and biologically active copolymers and their subsequent self-assembled cationic nanoparticles as better delivery vehicles for anticancer drugs to achieve the synergism between the cytotoxicity effects of the loaded drugs and the macrophage inflammatory response of the delivery vehicle. This family of cationic nanoparticles was formulated from a new family of amphiphilic cationic Arginine-Leucine (Arg-Leu)-based poly(ester urea urethane) (Arg-Leu PEUU) synthesized from four building blocks (amino acids, diols, glycerol α-monoallyl ether, and 1,6 hexamethylene diisocyanate). The chemical, physical, and biological properties of Arg-Leu PEUU biomaterials can be tuned by controlling the feed ratio of the four building blocks. The Arg-Leu PEUU copolymers have weight-average molecular weights from 13.4 to 16.8 kDa and glass-transition temperatures from -3.4 to -4.6 °C. The self-assembled cationic nanoparticles (Arg-Leu PEUU NPs) were prepared using a facile dialysis method. Arg-Leu PEUU NPs have average diameters ranging from 187 to 272 nm, show good biocompatibility with 3T3 fibroblasts, and they support bovine aortic endothelial cell (BAEC) proliferation and adhesion. Arg-Leu PEUU NPs also enhanced the macrophages' production of tumor necrosis factor-α (TNF-α) and nitric oxide (NO), but produced relatively low levels of interleukin-10 (IL-10), and therefore, the antitumor activity of macrophages might be enhanced. Arg-Leu PEUU NPs were taken up by HeLa cells after 4 h of incubation. The in vitro hemolysis assay showed the cationic Arg-Leu PEUU NPs increased their chance of endosomal escape at a more acidic pH. Doxorubicin (DOX) was successfully incorporated into the Arg-Leu PEUU NPs, and the DOX-loaded Arg-Leu PEUU NPs exhibited a pH-dependent drug release profile with accelerated release kinetics in a mild acidic condition. The DOX-loaded 6-Arg-4-Leu-4 A/L-2/1 NPs showed higher HeLa cell

  18. Biodegradable Eri silk nanoparticles as a delivery vehicle for bovine lactoferrin against MDA-MB-231 and MCF-7 breast cancer cells

    Directory of Open Access Journals (Sweden)

    Roy K

    2015-12-01

    Full Text Available Kislay Roy,1,* Yogesh S Patel,1,* Rupinder K Kanwar,1 Rangam Rajkhowa,2 Xungai Wang,2 Jagat R Kanwar1 1Nanomedicine-Laboratory of Immunology and Molecular Biomedical Research (NLIMBR, Centre for Molecular and Medical Research (C-MMR, School of Medicine (SoM, Faculty of Health, 2Institute for Frontier Materials (IFM, Deakin University, Waurn Ponds, VIC, Australia *These authors contributed equally to this work Abstract: This study used the Eri silk nanoparticles (NPs for delivering apo-bovine lactoferrin (Apo-bLf (~2% iron saturated and Fe-bLf (100% iron saturated in MDA-MB-231 and MCF-7 breast cancer cell lines. Apo-bLf and Fe-bLf-loaded Eri silk NPs with sizes between 200 and 300 nm (±10 nm showed a significant internalization within 4 hours in MDA-MB-231 cells when compared to MCF-7 cells. The ex vivo loop assay with chitosan-coated Fe-bLf-loaded silk NPs was able to substantiate its future use in oral administration and showed the maximum absorption within 24 hours by ileum. Both Apo-bLf and Fe-bLf induced increase in expression of low-density lipoprotein receptor-related protein 1 and lactoferrin receptor in epidermal growth factor (EGFR-positive MDA-MB-231 cells, while transferrin receptor (TfR and TfR2 in MCF-7 cells facilitated the receptor-mediated endocytosis of NPs. Controlled and sustained release of both bLf from silk NPs was shown to induce more cancer-specific cytotoxicity in MDA-MB-231 and MCF-7 cells compared to normal MCF-10A cells. Due to higher degree of internalization, the extent of cytotoxicity and apoptosis was significantly higher in MDA-MB-231 (EGFR+ cells when compared to MCF-7 (EGFR- cells. The expression of a prominent anti-cancer target, survivin, was found to be downregulated at both gene and protein levels. Taken together, all the observations suggest the potential use of Eri silk NPs as a delivery vehicle for an anti-cancer milk protein, and indicate bLf for the treatment of breast cancer. Keywords: breast

  19. Forgotten antibiotics

    DEFF Research Database (Denmark)

    Pulcini, Céline; Bush, Karen; Craig, William A;

    2012-01-01

    disease specialists in Europe, the United States, Canada, and Australia. An international expert panel selected systemic antibacterial drugs for their potential to treat infections caused by resistant bacteria or their unique value for specific criteria. Twenty-two of the 33 selected antibiotics were...... available in fewer than 20 of 38 countries. Economic motives were the major cause for discontinuation of marketing of these antibiotics. Fourteen of 33 antibiotics are potentially active against either resistant Gram-positive or Gram-negative bacteria. Urgent measures are then needed to ensure better...

  20. Antibiotic Resistance

    Science.gov (United States)

    ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products For Consumers Home For Consumers Consumer Information by Audience For Women Antibiotic Resistance Share Tweet Linkedin Pin it More ...

  1. Antibiotic-loaded plaster of Paris implants coated with poly lactide-co-glycolide as a controlled release delivery system for the treatment of bone infections

    OpenAIRE

    Benoit, M.-A.; Mousset, B.; Delloye, C.; Bouillet, R.; Gillard, J.

    1998-01-01

    m) of PLA45GA10. This delivery system was implanted into the femoral condyle of rabbits. It was shown that the in vivo release was also closely regulated by the coating depth. In all bone tissues (bone marrow and cortical bone) surrounding the pellets, the drug concentration exceeded the Minimum Inhibitory Concentration for the common causative organisms of bone infections (Staphylococcus aureus) for at least four weeks without inducing serum toxic levels. Due to its cheapness, facility of us...

  2. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  3. Antibiotic Resistance

    DEFF Research Database (Denmark)

    Munck, Christian

    morbidity and mortality as well as an increase in the cost of treatment. Understanding how bacteria respond to antibiotic exposure gives the foundations for a rational approach to counteract antimicrobial resistance. In the work presented in this thesis, I explore the two fundamental sources of...... antimicrobial resistance: (1) adaptive mutations and (2) horizontal acquisition of resistance genes from antibiotic gene reservoirs. By studying the geno- and phenotypic changes of E. coli in response to single and drug-pair exposures, I uncover the evolutionary trajectories leading to adaptive resistance. I...... to rationally design drug combinations that limit the evolution of antibiotic resistance due to counteracting evolutionary trajectories. My results highlight that an in-depth knowledge about the genetic responses to the individual antimicrobial compounds enables the prediction of responses to drug...

  4. Preparation and in vitro characterization of gentamycin-impregnated biodegradable beads suitable for treatment of osteomyelitis.

    Science.gov (United States)

    Meyer, J D; Falk, R F; Kelly, R M; Shively, J E; Withrow, S J; Dernell, W S; Kroll, D J; Randolph, T W; Manning, M C

    1998-09-01

    A new method for preparing poly(L-lactide) (PLA) biodegradable beads impregnated with an ionic aminoglycoside, gentamycin, is described. The process employs hydrophobic ion pairing to solubilize gentamycin in a solvent compatible with PLA, followed by precipitation with a compressed antisolvent (supercritical carbon dioxide). The resulting precipitate is a homogeneous dispersion of the ion-paired drug in PLA microspheres. The microspheres are approximately 1 microm in diameter and can be compressed into beads (3-6 mm in diameter) strung on surgical sutures for implantation. The bead strings exhibit no significant change in release kinetics upon sterilization with a hydrogen peroxide plasma (Ster-Rad). The kinetics of gentamycin release from the PLA beads are consistent with a matrix-controlled diffusion mechanism. While nonbiodegradable poly(methyl methacrylate) (PMMA) beads initially release gentamycin in a similar manner, the drug release from PMMA ceases after 8 or 9 weeks, while the PLA beads continue to release drug for over 4 months. Moreover, only 10% of the gentamycin is released from the PMMA beads, while PLA beads release more than 60% of their load, if serum is present in the release medium. The PLA system displays improved release kinetics relative to PMMA, is biodegradable, is unaltered by gas sterilization, can be used for a range of antibiotics, and can be manipulated without disintegration. These are all desirable properties for an implantable drug delivery system for the prevention or treatment of osteomyelitis. PMID:9724569

  5. Nanomembranes and nanofibers from biodegradable conducting polymers

    OpenAIRE

    Jordi Puiggalí; Carlos Alemán; Luís Javier del Valle; Elaine Armelin; María del Mar Pérez-Madrigal; Elena Llorens

    2013-01-01

    This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e. g., aliphatic polyesters such as polylactide or polycaprolactone) and conducting polymers (e. g., polyaniline, polypirrole or polythiophenes). These materials have potential biomedical applications (e. g., tissue engineering or drug delivery systems) and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their correspon...

  6. Disposition and safety of inhaled biodegradable nanomedicines: Opportunities and challenges.

    Science.gov (United States)

    Haque, Shadabul; Whittaker, Michael R; McIntosh, Michelle P; Pouton, Colin W; Kaminskas, Lisa M

    2016-08-01

    The inhaled delivery of nanomedicines can provide a novel, non-invasive therapeutic strategy for the more localised treatment of lung-resident diseases and potentially also enable the systemic delivery of therapeutics that are otherwise administered via injection alone. However, the clinical translation of inhalable nanomedicine is being hampered by our lack of understanding about their disposition and clearance from the lungs. This review provides a comprehensive overview of the biodegradable nanomaterials that are currently being explored as inhalable drug delivery systems and our current understanding of their disposition within, and clearance from the lungs. The safety of biodegradable nanomaterials in the lungs is discussed and latest updates are provided on the impact of inflammation on the pulmonary pharmacokinetics of inhaled nanomaterials. Overall, the review provides an in-depth and critical assessment of the lung clearance mechanisms for inhaled biodegradable nanomedicines and highlights the opportunities and challenges for their translation into the clinic. PMID:27033834

  7. Grey water biodegradability.

    Science.gov (United States)

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively. PMID:20658309

  8. Psyllium and copolymers of 2-hydroxylethylmethacrylate and acrylamide-based novel devices for the use in colon specific antibiotic drug delivery.

    Science.gov (United States)

    Singh, Baljit; Chauhan, Nirmala; Kumar, S; Bala, Ritu

    2008-03-20

    In order to utilize the psyllium husk, a medicinally important natural polysaccharide, to develop the hydrogels meant for the drug delivery, we have prepared psyllium 2-hydroxylethylmethacrylate (HEMA) and acrylamide (AAm)-based polymeric networks by using N,N'-methylenebisacrylamide (N,N'-MBAAm) as crosslinker and ammonium persulfate (APS) as initiator. The polymeric networks thus formed [psy-cl-poly(HEMA-co-AAm)] were characterized with FTIR and swelling studies which were carried out as a function of crosslinker concentration, time, pH and [NaCl] of the swelling medium. The swelling kinetics of the hydrogels and in vitro release dynamics of model drug (tetracycline hydrochloride) from these hydrogels has been studied for the evaluation of swelling mechanism and drug release mechanism from the hydrogels. The values of the diffusion exponent 'n' have been obtained 0.5 for both swelling kinetics and drug release dynamics. This value shows that the Fickian type diffusion mechanism has occurred for the swelling of the polymers and for the release of drug from the polymers in different release mediums. The values of the initial diffusion coefficients (10.6 x 10(-4), 13.1 x 10(-4), 14.0 x 10(-4))cm(2)/min, average diffusion coefficients (22.2 x 10(-4), 25.7 x 10(-4), 27.0 x 10(-4))cm(2)/min and late diffusion coefficients (1.68 x 10(-4), 2.15 x 10(-4), 2.28 x 10(-4))cm(2)/min for the release of tetracycline HCl respectively in distilled water, pH 2.2 buffer and pH 7.4 buffer from the drug loaded samples shows that in the initial stages, the rate of release of drug from the hydrogels is slow and rate of diffusion of drug increases with time. PMID:18055144

  9. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  10. How UV photolysis accelerates the biodegradation and mineralization of sulfadiazine (SD).

    Science.gov (United States)

    Pan, Shihui; Yan, Ning; Liu, Xinyue; Wang, Wenbing; Zhang, Yongming; Liu, Rui; Rittmann, Bruce E

    2014-11-01

    Sulfadiazine (SD), one of broad-spectrum antibiotics, exhibits limited biodegradation in wastewater treatment due to its chemical structure, which requires initial mono-oxygenation reactions to initiate its biodegradation. Intimately coupling UV photolysis with biodegradation, realized with the internal loop photobiodegradation reactor, accelerated SD biodegradation and mineralization by 35 and 71 %, respectively. The main organic products from photolysis were 2-aminopyrimidine (2-AP), p-aminobenzenesulfonic acid (ABS), and aniline (An), and an SD-photolysis pathway could be identified using C, N, and S balances. Adding An or ABS (but not 2-AP) into the SD solution during biodegradation experiments (no UV photolysis) gave SD removal and mineralization rates similar to intimately coupled photolysis and biodegradation. An SD biodegradation pathway, based on a diverse set of the experimental results, explains how the mineralization of ABS and An (but not 2-AP) provided internal electron carriers that accelerated the initial mono-oxygenation reactions of SD biodegradation. Thus, multiple lines of evidence support that the mechanism by which intimately coupled photolysis and biodegradation accelerated SD removal and mineralization was through producing co-substrates whose oxidation produced electron equivalents that stimulated the initial mono-oxygenation reactions for SD biodegradation. PMID:25199943

  11. Green and biodegradable electronics

    OpenAIRE

    Mihai Irimia-Vladu; Eric. D. Głowacki; Gundula Voss; Siegfried Bauer; Niyazi Serdar Sariciftci

    2012-01-01

    We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials sugg...

  12. Beyond Antibiotics?

    Directory of Open Access Journals (Sweden)

    LE Nicolle

    2006-01-01

    Full Text Available The AMMI Canada meeting in March 2006 hosted a symposium exploring the potential alternatives to antibiotics for the prevention and treatment of infection. Four papers summarizing talks from that session are published in this issue of the Journal (1-4. These reviews address the scientific underpinnings for a number of proposed concepts, and summarize the current status of clinical use. The approaches - probiotics, bacteriophage therapy, and manipulation of innate immunity - are all intriguing but are still removed from immediate practical applications.

  13. Controlled morphology of biodegradable polymer blends

    Science.gov (United States)

    Buddhiranon, Sasiwimon; Kyu, Thein

    2009-03-01

    Phase diagrams of biodegradable polymer blends containing poly(ɛ-caprolactone) (PCL) and poly(d,l-lactic acid) (PDLLA) having two different molecular weights were established by means of cloud point measurement and differential scanning calorimetry. Subsequently, the theoretical phase diagram was calculated self-consistently based on the combination of Flory-Huggins free energy for liquid-liquid phase separation and phase field free energy for crystal solidification. The phase diagrams thus obtained were LCST type or hour-glass type, which depended on molecular weight of PDLLA utilized. Guided by the phase diagram, the emerged morphology was determined as a function of blend concentration and temperature. It appears that the morphology control is feasible that ultimately affects the end-use property of PCL/PDLLA blends. A wide variety of morphology of biodegradable polymer may be developed with the porous structure and pore size to control scaffold porosity and the rate of drug delivery.

  14. Facts about Antibiotic Resistance

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  15. Antibiotic / Antimicrobial Resistance Glossary

    Science.gov (United States)

    ... Recommendations Pediatric Treatment Recommendations Inpatient Healthcare Professionals Community Pharmacists Continuing Education & Curriculum Opportunities Weighing in on Antibiotic Resistance Improving Prescribing Outpatient Antibiotic Stewardship Interventions That Work Systematic Reviews ...

  16. Polyester Dendrimers: Smart Carriers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Jean–d’Amour K. Twibanire

    2014-01-01

    Full Text Available Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  17. Polyester Dendrimers: Smart Carriers for Drug Delivery

    OpenAIRE

    Jean–d’Amour K. Twibanire; T. Bruce Grindley

    2014-01-01

    Polyester dendrimers have been shown to be outstanding candidates for biomedical applications. Compared to traditional polymeric drug vehicles, these biodegradable dendrimers show excellent advantages especially as drug delivery systems because they are non-toxic. Here, advances on polyester dendrimers as smart carriers for drug delivery applications have been surveyed. Both covalent and non-covalent incorporation of drugs are discussed.

  18. Green and biodegradable electronics

    Directory of Open Access Journals (Sweden)

    Mihai Irimia-Vladu

    2012-07-01

    Full Text Available We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials suggest they will be useful in biofunctional electronics; demonstrating functions that would be inaccessible for traditional inorganic compounds. Such materials may lead to fully biodegradable and even biocompatible/biometabolizable electronics for many low-cost applications. This review highlights recent progress in these classes of material, covering substrates and insulators, semiconductors, and finally conductors.

  19. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  20. Biodegradable polymers: emerging excipients for the pharmaceutical and medical device industries.

    Directory of Open Access Journals (Sweden)

    Bhavesh Patel

    2013-12-01

    Full Text Available Worldwide many researchers are exploring the potential use of biodegradable polymerics as carriers for a wide range of therapeutic applications. In the past two decades, considerable progress has been made in the development of biodegradable polymeric materials, mainly in the biomedical and pharmaceutical industries due to their versatility, biocompatibility and biodegradability properties. The present review focuses on the use of biodegradable polymers in various therapeutic areas like orthopedic and contraceptive device, surgical sutures, implants, depot parenteral injections, etc. Biodegradable polymers have also contributed significantly to the development of drug-eluting stents (DES used for the treatment of obstructive coronary artery disease, such as angioplasty. Biodegradable synthetic polymers have potential applications in orthopedic device fixation due to properties that impact bone healing, formation, regeneration or substitution in the human body. The present review also emphasizes areas such as the chemistry of polymer synthesis, factors affecting the biodegradation, methods for the production of biodegradable polymer based formulations, the application of biodegradable polymers in dental implants, nasal drug deliveries, contraceptive devices, immunology, gene, transdermal, ophthalmic and veterinary applications, as well as, the sterilization of biodegradable based formulations and regulatory considerations for product filing.

  1. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  2. Modification of microbial polyacids for drug delivery systems

    OpenAIRE

    Lanz Landázuri, Alberto

    2014-01-01

    Polymers are becoming preferred materials in biomedical applications because of their vast diversity of properties, functionalities and applications. Properties as mechanical strength, stability against degradation, biocompatibility and biodegradability, among others, have been attractive for different medical applications. One of the most interesting applications of these materials is drug delivery systems. Biodegradable polymers and copolymers are the preferred materials for the manufacture...

  3. Seaweed Polysaccharide-Based Nanoparticles: Preparation and Applications for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Jayachandran Venkatesan

    2016-01-01

    Full Text Available In recent years, there have been major advances and increasing amounts of research on the utilization of natural polymeric materials as drug delivery vehicles due to their biocompatibility and biodegradability. Seaweed polysaccharides are abundant resources and have been extensively studied for several biological, biomedical, and functional food applications. The exploration of seaweed polysaccharides for drug delivery applications is still in its infancy. Alginate, carrageenan, fucoidan, ulvan, and laminarin are polysaccharides commonly isolated from seaweed. These natural polymers can be converted into nanoparticles (NPs by different types of methods, such as ionic gelation, emulsion, and polyelectrolyte complexing. Ionic gelation and polyelectrolyte complexing are commonly employed by adding cationic molecules to these anionic polymers to produce NPs of a desired shape, size, and charge. In the present review, we have discussed the preparation of seaweed polysaccharide-based NPs using different types of methods as well as their usage as carriers for the delivery of various therapeutic molecules (e.g., proteins, peptides, anti-cancer drugs, and antibiotics. Seaweed polysaccharide-based NPs exhibit suitable particle size, high drug encapsulation, and sustained drug release with high biocompatibility, thereby demonstrating their high potential for safe and efficient drug delivery.

  4. Compared in vivo toxicity in mice of lung delivered biodegradable and non-biodegradable nanoparticles.

    Science.gov (United States)

    Aragao-Santiago, Letícia; Hillaireau, Hervé; Grabowski, Nadège; Mura, Simona; Nascimento, Thais L; Dufort, Sandrine; Coll, Jean-Luc; Tsapis, Nicolas; Fattal, Elias

    2016-04-01

    To design nanoparticle (NP)-based drug delivery systems for pulmonary administration, biodegradable materials are considered safe, but their potential toxicity is poorly explored. We here explore the lung toxicity in mice of biodegradable nanoparticles (NPs) and compare it to the toxicity of non-biodegradable ones. NP formulations of poly(d,l-lactide-co-glycolide) (PLGA) coated with chitosan (CS), poloxamer 188 (PF68) or poly(vinyl alcohol) (PVA), which renders 200 nm NPs of positive, negative or neutral surface charge respectively, were analyzed for their biodistribution by in vivo fluorescence imaging and their inflammatory potential after single lung nebulization in mice. After exposure, analysis of bronchoalveolar lavage (BAL) cell population, protein secretion and cytokine release as well as lung histology were carried out. The inflammatory response was compared to the one induced by non-biodegradable counterparts, namely, TiO2 of rutile and anatase crystal form and polystyrene (PS). PLGA NPs were mostly present in mice lungs, with little passage to other organs. An increase in neutrophil recruitment was observed in mice exposed to PS NPs 24 h after nebulization, which declined at 48 h. This result was supported by an increase in interleukin (IL)-6 and tumor necrosis factor α (TNFα) in BAL supernatant at 24 h. TiO2 anatase NPs were still present in lung cells 48 h after nebulization and induced the expression of pro-inflammatory cytokines and the recruitment of polymorphonuclear cells to BAL. In contrast, regardless of their surface charge, PLGA NPs did not induce significant changes in the inflammation markers analyzed. In conclusion, these results point out to a safe use of PLGA NPs regardless of their surface coating compared to non-biodegradable ones. PMID:26573338

  5. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  6. Enzymatic oxidative biodegradation of nanoparticles: Mechanisms, significance and applications.

    Science.gov (United States)

    Vlasova, Irina I; Kapralov, Alexandr A; Michael, Zachary P; Burkert, Seth C; Shurin, Michael R; Star, Alexander; Shvedova, Anna A; Kagan, Valerian E

    2016-05-15

    Biopersistence of carbon nanotubes, graphene oxide (GO) and several other types of carbonaceous nanomaterials is an essential determinant of their health effects. Successful biodegradation is one of the major factors defining the life span and biological responses to nanoparticles. Here, we review the role and contribution of different oxidative enzymes of inflammatory cells - myeloperoxidase, eosinophil peroxidase, lactoperoxidase, hemoglobin, and xanthine oxidase - to the reactions of nanoparticle biodegradation. We further focus on interactions of nanomaterials with hemoproteins dependent on the specific features of their physico-chemical and structural characteristics. Mechanistically, we highlight the significance of immobilized peroxidase reactive intermediates vs diffusible small molecule oxidants (hypochlorous and hypobromous acids) for the overall oxidative biodegradation process in neutrophils and eosinophils. We also accentuate the importance of peroxynitrite-driven pathways realized in macrophages via the engagement of NADPH oxidase- and NO synthase-triggered oxidative mechanisms. We consider possible involvement of oxidative machinery of other professional phagocytes such as microglial cells, myeloid-derived suppressor cells, in the context of biodegradation relevant to targeted drug delivery. We evaluate the importance of genetic factors and their manipulations for the enzymatic biodegradation in vivo. Finally, we emphasize a novel type of biodegradation realized via the activation of the "dormant" peroxidase activity of hemoproteins by the nano-surface. This is exemplified by the binding of GO to cyt c causing the unfolding and 'unmasking' of the peroxidase activity of the latter. We conclude with the strategies leading to safe by design carbonaceous nanoparticles with optimized characteristics for mechanism-based targeted delivery and regulatable life-span of drugs in circulation. PMID:26768553

  7. Benzotriazole and Sulfamethoxazole - Biodegradation of polar, non-adsorptive xenobiotic micropollutants with activated sludge communities and pure cultures

    OpenAIRE

    Herzog, Bastian

    2015-01-01

    Biodegradation of three benzotriazoles and the antibiotic sulfamethoxazole has been evaluated under different redox and nutrient conditions with activated sludge communities and pure cultures. Two benzotriazoles and sulfamethoxazole were biodegradable under aerobic conditions but not under anoxic or anaerobic conditions. 4-methyl-benzotriazole was biologically stable under all conditions tested. A monitoring study over one year in three different wastewater treatment plants showed a similar b...

  8. Strengthening Control of Antibiotics

    Institute of Scientific and Technical Information of China (English)

    EthelLu

    2005-01-01

    IT is a well-known fact that buy-ng guns is much easier than purchasing antibiotics in the United States. In China, however, the situation is different. According to a recent WHO survey,about 80 percent of Chinese inpatients take antibiotic medicines, and 58 percent of them are prescribed multifunctional antibiotics,

  9. Know When Antibiotics Work

    Centers for Disease Control (CDC) Podcasts

    2015-04-15

    This podcast provides a brief background about antibiotics and quick tips to help prevent antibiotic resistance.  Created: 4/15/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program.   Date Released: 4/16/2015.

  10. Antibiotic resistant in microorganisms

    Science.gov (United States)

    Antimicrobial agents are necessary for use in veterinary medicine including the production of food producing animals. Antibiotic use is indicated for the treatment of bacterial target organisms and/or disease for which the antibiotic was developed. However, an unintended consequence of antibiotic ...

  11. Long-term release of clodronate from biodegradable microspheres

    OpenAIRE

    Perugini, Paola; Genta, Ida; Conti, Bice; Modena, Tiziana; Pavanetto, Franca

    2001-01-01

    This paper describes the formulation of a biodegradable microparticulate drug delivery system containing clodronate, a bisphosphonate intended for the treatment of bone diseases. Microspheres were prepared with several poly(D,L-lactide-co-glycolide) (PLGA) copolymers of various molecular weights and molar compositions and 1 poly(D,L-lactide) (PDLLA) homopolymer by a water-in-oil-in-water (w/o/w) double emulsion solvent evaporation procedure. Critical process parameters and formulation variabl...

  12. Biodegradable polymer gadolinium contrast agents for magnetic resonance imaging

    Czech Academy of Sciences Publication Activity Database

    Braunová, Alena; Kříž, Jaroslav; Pechar, Michal; Šubr, Vladimír; Ulbrich, Karel

    Egmond aan Zee : University of Twente, 2012 - (Engbersen, J.), s. 72-73 [European Symposium on Controlled Drug Delivery /12./. Egmond aan Zee (NL), 04.04.2012-06.04.2012] R&D Projects: GA AV ČR IAAX00500803 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : biodegradable polymer carrier * polyethylene glycol * PEG Subject RIV: CD - Macromolecular Chemistry

  13. AS1411 Aptamer-Decorated Biodegradable Polyethylene Glycol-Poly(lactic-co-glycolic acid) Nanopolymersomes for the Targeted Delivery of Gemcitabine to Non-Small Cell Lung Cancer In Vitro.

    Science.gov (United States)

    Alibolandi, Mona; Ramezani, Mohammad; Abnous, Khalil; Hadizadeh, Farzin

    2016-05-01

    Molecularly targeted drug delivery systems represent a novel therapeutic strategy in the treatment of different cancers. In the present study, we have developed gemcitabine (GEM)-loaded AS1411 aptamer surface-decorated polyethylene glycol-poly(lactic-co-glycolic acid) nanopolymersome (Apt-GEM-NP) to target nucleolin-overexpressing non-small cell lung cancer (NSCLC; A549). The prepared Apt-GEM-NP showed average particle size of 128 ± 5.23 nm and spherical morphology with encapsulation efficiency and loading content of 95.32 ± 2.37% and 8.61 ± 0.27%, respectively. Apt-GEM-NP exhibited a controlled release pattern. A sustained release of drug in physiological conditions will greatly improve the chemotherapeutic efficiency of a system. Enhanced cellular uptake and the cytotoxicity of aptamer-conjugated nanoparticles (NPs) in A549 cancer cells obviously verified nucleolin-mediated receptor-based active targeting. Nucleolin-mediated internalization of the targeted polymeric NP was further confirmed by flow cytometry and fluorescence microscopy. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay clearly showed the enhanced cell proliferation inhibitory effect of AS1411-conjugated NP on account of the selective delivery of GEM to the nucleolin-overexpressing cancer cells. Our results showed that AS1411 aptamer conjugation on the surface of NP could be a potential treatment strategy for A549 as a nucleolin-overexpressing cell line. This suggests that AS1411-GEM-NPs could be potentially used for the treatment of NSCLC. PMID:27039356

  14. A REVIEW ON CHITOSAN-BASED HYDROGLES FOR THE DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Venkatesan Praveen Kumar

    2011-02-01

    Full Text Available Chitosan is a natural polymer obtained by deacetylation of chitin. It is biologically safe, non-toxic, biocompatible and biodegradable polysaccharide. Chitosan is a good candidate for site-specific drug delivery. Hydro gels are potential candidates in controlled release applications. It is due to their soft tissue biocompatibility, the ease with which the drugs are dispersed in the matrix and high degree of control achieved by selecting physical and chemical properties of polymer network. The aim of this review is to provide insight into the applications of chitosan based hydro gels for the drug delivery through different routes. These chitosan-based hydro gels are very essential in the sustained release of antibiotics to reach the target site. This article reviews focused on entire features of chitosan-based hydrogles in both as a drug delivery matrix system and a system for tissue engineering as well as its potential therapeutic applications. Finally it can be concluded that chitosan-based hydro gels offers a novel way for the sustained release of drugs to treat localized infections.

  15. Preparation of a biodegradable oil absorber and its biodegradation.

    Science.gov (United States)

    Yoo, Su-Yong; Daud, Wan Mohd Ashri Wan; Lee, Min-Gyu

    2012-01-01

    The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%. PMID:21909668

  16. Recent advances in chitosan-based nanoparticulate pulmonary drug delivery.

    Science.gov (United States)

    Islam, Nazrul; Ferro, Vito

    2016-08-14

    The advent of biodegradable polymer-encapsulated drug nanoparticles has made the pulmonary route of administration an exciting area of drug delivery research. Chitosan, a natural biodegradable and biocompatible polysaccharide has received enormous attention as a carrier for drug delivery. Recently, nanoparticles of chitosan (CS) and its synthetic derivatives have been investigated for the encapsulation and delivery of many drugs with improved targeting and controlled release. Herein, recent advances in the preparation and use of micro-/nanoparticles of chitosan and its derivatives for pulmonary delivery of various therapeutic agents (drugs, genes, vaccines) are reviewed. Although chitosan has wide applications in terms of formulations and routes of drug delivery, this review is focused on pulmonary delivery of drug-encapsulated nanoparticles of chitosan and its derivatives. In addition, the controversial toxicological effects of chitosan nanoparticles for lung delivery will also be discussed. PMID:27439116

  17. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  18. Gas foamed open porous biodegradable polymeric microspheres.

    Science.gov (United States)

    Kim, Taek Kyoung; Yoon, Jun Jin; Lee, Doo Sung; Park, Tae Gwan

    2006-01-01

    Highly open porous biodegradable polymeric microspheres were fabricated for use as injectable scaffold microcarriers for cell delivery. A modified water-in-oil-in-water (W1/O/W2) double emulsion solvent evaporation method was employed for producing the microspheres. The incorporation of an effervescent salt, ammonium bicarbonate, in the primary W1 droplets spontaneously produced carbon dioxide and ammonia gas bubbles during the solvent evaporation process, which not only stabilized the primary emulsion, but also created well inter-connected pores in the resultant microspheres. The porous microspheres fabricated under various gas foaming conditions were characterized. The surface pores became as large as 20 microm in diameter with increasing the concentration of ammonium bicarbonate, being sufficient enough for cell infiltration and seeding. These porous scaffold microspheres could be potentially utilized for cultivating cells in a suspension manner and for delivering the seeded cells to the tissue defect site in an injectable manner. PMID:16023197

  19. Frontline antibiotic therapy.

    Science.gov (United States)

    MacGowan, Alasdair; Albur, Maha

    2013-06-01

    The need to use front-line antibiotics wisely has never been greater. Antibiotic resistance and multi-drug resistant infection, driven by antibiotic use, remain major public health and professional concerns. To overcome these infection problems, use of older antibiotics active against multi drug-resistant pathogens is increasing - for example, colistin, fosfomycin, pivmecillinam, pristinamycin, temocillin and oral tetracyclines. The number of new antibacterials reaching clinical practice has reduced significantly in the last 20 years, most being focused on therapy of Gram-positive infection - eg linezolid, daptomycin, telavancin and ceftaroline. Recent guidance on antibiotic stewardship in NHS trusts in England is likely to provide a backdrop to antibiotic use in hospitals in the next 5 years. PMID:23760700

  20. High Antibiotic Consumption

    DEFF Research Database (Denmark)

    Malo, Sara; José Rabanaque, María; Feja, Cristina;

    2014-01-01

    a high proportion of antibiotics not recommended as first choice in primary health care. In conclusion, heavy antibiotic users consisted mainly of children and old adults. Inappropriate overuse of antibiotics (high quantity, high frequency, and inappropriate antibiotic choice) leads to a substantial...... individuals with highest consumption) were responsible for 21% of the total DDD consumed and received ≥6 packages per year. Elderly adults (≥60 years) and small children (0-9 years) were those exposed to the highest volume of antibiotics and with the most frequent exposure, respectively. Heavy users received...... risk of the emergence and spread of resistant bacteria, and interventions to reduce overuse of antibiotics should therefore primarily be targeted children and elderly people....

  1. Understanding Antibiotic Resistance

    OpenAIRE

    Goulart-Touma, Christiane

    2014-01-01

    The evolution of antibiotic resistance among bacteria threatens our continued ability to treat infectious diseases. The need for sustainable strategies to cure bacterial infections has never been greater. So far, all attempts to restore susceptibility after resistance arises have been unsuccessful, including restrictions on prescribing antibiotics (Andersson DI et al.2011) and antibiotic cycling (Andersson DI et al. 2005, Bergstrom CT et al. 2004). Part of the problem may be that those effor...

  2. Biodegradation of biodiesel fuels

    International Nuclear Information System (INIS)

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO2 evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO2 evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO2 evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO2. The test substances were examined for BOD5 and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD5 and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD5 and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p 5 value

  3. Adenosine-Associated Delivery Systems

    Science.gov (United States)

    Kazemzadeh-Narbat, Mehdi; Annabi, Nasim; Tamayol, Ali; Oklu, Rahmi; Ghanem, Amyl; Khademhosseini, Ali

    2016-01-01

    Adenosine is a naturally occurring purine nucleoside in every cell. Many critical treatments such as modulating irregular heartbeat (arrhythmias), regulation of central nervous system (CNS) activity, and inhibiting seizural episodes can be carried out using adenosine. Despite the significant potential therapeutic impact of adenosine and its derivatives, the severe side effects caused by their systemic administration have significantly limited their clinical use. In addition, due to adenosine’s extremely short half-life in human blood (less than 10 s), there is an unmet need for sustained delivery systems to enhance efficacy and reduce side effects. In this paper, various adenosine delivery techniques, including encapsulation into biodegradable polymers, cell-based delivery, implantable biomaterials, and mechanical-based delivery systems, are critically reviewed and the existing challenges are highlighted. PMID:26453156

  4. Antibiotics: Miracle Drugs

    Centers for Disease Control (CDC) Podcasts

    2015-04-16

    The overuse of antibiotics has led to the development of resistance among bacteria, making antibiotics ineffective in treating certain conditions. This podcast discusses the importance of talking to your healthcare professional about whether or not antibiotics will be beneficial if you’ve been diagnosed with an infectious disease.  Created: 4/16/2015 by Division of Bacterial Diseases (DBD), National Center for Immunization and Respiratory Disease (NCIRD), Get Smart: Know When Antibiotics Work Program.   Date Released: 4/16/2015.

  5. Structure of polysaccharide antibiotics

    International Nuclear Information System (INIS)

    Study of the structure of antibiotics having two or several sugars in their molecule. One may distinguish: the polysaccharide antibiotics themselves, made up of two or several sugars either with or without nitrogen, such as streptomycin, neomycins, paromomycine, kanamycin, chalcomycin; the hetero-polysaccharide antibiotics made up of one saccharide part linked to an aglycone of various type through a glucoside: macrolide, pigment, pyrimidine purine. Amongst these latter are: erythromycin, magnamycin, spiramycin, oleandomycin, cinerubin and amicetin. The sugars can either play a direct role in biochemical reactions or act as a dissolving agent, as far as the anti-microbe power of these antibiotics is concerned. (author)

  6. FOSSIL FUEL BIODEGRADATION: LABORATORY STUDIES

    Science.gov (United States)

    Natural processes of biodegradation, that return carbon from its various organic forms to the inorganic state, are increasingly screened for bioremediation applications. ariety of microbial systems capable of degrading synthetic organic chemicals, from pesticides to polychlorinat...

  7. Pharmacokinetics and biodegradation performance of a hydroxypropyl chitosan derivative

    Science.gov (United States)

    Shao, Kai; Han, Baoqin; Dong, Wen; Song, Fulai; Liu, Weizhi; Liu, Wanshun

    2015-10-01

    Hydroxypropyl chitosan (HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical and pharmaceutical fields. However, it is not yet known about its pharmacokinetics and biodegradation performance, which are crucial for its clinical applications. In order to lay a foundation for its further applications and exploitations, here we carried out fluorescence intensity and GPC analyses to determine the pharmacokinetics mode of fluorescein isothiocyanate-labeled HP-chitosan (FITC-HP-chitosan) and its biodegradability. The results showed that after intraperitoneal administration at a dose of 10 mg per rat, FITC-HP-chitosan could be absorbed rapidly and distributed to liver, kidney and spleen through blood. It was indicated that FITC-HP-chitosan could be utilized effectively, and 88.47% of the FITC-HP-chitosan could be excreted by urine within 11 days with a molecular weight less than 10 kDa. Moreover, our data indicated that there was an obvious degradation process occurred in liver (chitosan has excellent bioavailability and biodegradability, suggesting the potential applications of hydroxypropyl-modified chitosan as materials in drug delivery, tissue engineering and biomedical area.

  8. Anaerobic biodegradability of kitchen waste

    OpenAIRE

    Neves, L.; Oliveira, Rosário; M. Mota; Alves, M.M.

    2002-01-01

    Biodegradability of synthetic and real kitchen wastes was assessed in batch assays, under different solid contents between 1,8 and 24% and waste/inoculum ratios between 0,2 and 29 VSwaste/Vsseed sludge. Methanization rate and cumulative methane production from synthetic wastes simulated with different blends of protein, carbohydrates, fat and cellulose were compared. Although the excess of protein, carbohydrates and cellulose enhanced the biodegradability by 16 to 48%, the excess of fat re...

  9. Drug Delivery Systems, CNS Protection, and the Blood Brain Barrier

    OpenAIRE

    Ravi Kant Upadhyay

    2014-01-01

    Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations insi...

  10. The polymethylmethacrylate antibiotic spacer for treatment of joint infection

    Directory of Open Access Journals (Sweden)

    Manuel Bondi

    2014-09-01

    Full Text Available Joint prostheses chronic infection requires surgical removal of the implant, in order to eradicate the infection process. The Polymethylmethacrylate (PMMA bone cement is a good carrier for the sustained antibiotic release at the site of infection. PMMA cements pre-loaded with antibiotics are utilized for prophylaxis, primary surgical procedure and the treatment of prosthetic joint infections. The mechanical and functional characteristics of the spacers allow a good joint range of motion, weight-bearing in selected cases and a sustained release of antibiotic at the site of infection. These drug delivery systems offer the advantage of local release of high antibiotic concentrations, which considerably exceed those obtained after systemic administration. Nowadays treatment with a preformed antibiotic loaded spacer can be considered a good option for joint prostheses infection maintaining joint function at the intermediate stage in two-stage treatment.

  11. The future of antibiotics.

    Science.gov (United States)

    Spellberg, Brad

    2014-01-01

    Antibiotic resistance continues to spread even as society is experiencing a market failure of new antibiotic research and development (R&D). Scientific, economic, and regulatory barriers all contribute to the antibiotic market failure. Scientific solutions to rekindle R&D include finding new screening strategies to identify novel antibiotic scaffolds and transforming the way we think about treating infections, such that the goal is to disarm the pathogen without killing it or modulate the host response to the organism without targeting the organism for destruction. Future economic strategies are likely to focus on 'push' incentives offered by public-private partnerships as well as increasing pricing by focusing development on areas of high unmet need. Such strategies can also help protect new antibiotics from overuse after marketing. Regulatory reform is needed to re-establish feasible and meaningful traditional antibiotic pathways, to create novel limited-use pathways that focus on highly resistant infections, and to harmonize regulatory standards across nations. We need new antibiotics with which to treat our patients. But we also need to protect those new antibiotics from misuse when they become available. If we want to break the cycle of resistance and change the current landscape, disruptive approaches that challenge long-standing dogma will be needed. PMID:25043962

  12. Immunomodulatory actions of antibiotics

    Directory of Open Access Journals (Sweden)

    Minić Svetlana

    2009-01-01

    Full Text Available Introduction. Antimicrob drugs and immune system interaction has been studied since the pioneer works of Metchnikoff. After the introduction of antibiotics in clinical practice this area has attracted little attention of investigators, because of the lack of standards. This is the reason that the studying of the influence of antibiotics on immune system is still at its beginning. Aim: To point out the immunomodulatory action of some antibiotics on certain components of immune system. Methods and results. The literaure findings show that antibiotics exspress immunomodulatory action on some components of immune system such as fagocytes (polymorphonucleary, macrophages, monocytes, cytokines, immunoglobulines, and on cellular immunity. The principles of antibiotics action on phagocyte are the inhibition of chemotaxis and oxidants production. Macrolides applied for a short time enchance the phagocytic functions while their long use leads to immunosupression. Some cephalosporines and rifampicin in therapeutic doses inhibit the oxydative metabolism of macrophages. Tetracyclines, clindamycines, chloramphenicol and tobramycin inhibit the synthesis of superoxyd anione. The action of some antibiotics on cytokine and specific antibodies is also important. Cellular immunity can be affected as well. After administration of certain antibiotics it takes 1-2 weeks to reestablish normal cellular immunity, and for other even more. Conclusion. There is still no clear standing on real effects of antibiotics on the immune system. Clinicians should search for more information from this new-old field of investigation in order to give more adequate therapy to patients.

  13. Polyanhydride Nanoparticle Delivery Platform Dramatically Enhances Killing of Filarial Worms.

    Directory of Open Access Journals (Sweden)

    Andrea M Binnebose

    Full Text Available Filarial diseases represent a significant social and economic burden to over 120 million people worldwide and are caused by endoparasites that require the presence of symbiotic bacteria of the genus Wolbachia for fertility and viability of the host parasite. Targeting Wolbachia for elimination is a therapeutic approach that shows promise in the treatment of onchocerciasis and lymphatic filariasis. Here we demonstrate the use of a biodegradable polyanhydride nanoparticle-based platform for the co-delivery of the antibiotic doxycycline with the antiparasitic drug, ivermectin, to reduce microfilarial burden and rapidly kill adult worms. When doxycycline and ivermectin were co-delivered within polyanhydride nanoparticles, effective killing of adult female Brugia malayi filarial worms was achieved with approximately 4,000-fold reduction in the amount of drug used. Additionally the time to death of the macrofilaria was also significantly reduced (five-fold when the anti-filarial drug cocktail was delivered within polyanhydride nanoparticles. We hypothesize that the mechanism behind this dramatically enhanced killing of the macrofilaria is the ability of the polyanhydride nanoparticles to behave as a Trojan horse and penetrate the cuticle, bypassing excretory pumps of B. malayi, and effectively deliver drug directly to both the worm and Wolbachia at high enough microenvironmental concentrations to cause death. These provocative findings may have significant consequences for the reduction in the amount of drug and the length of treatment required for filarial infections in terms of patient compliance and reduced cost of treatment.

  14. Factorial effect of process parameters on pharmaceutical characteristics of biodegradable PLGA microparticles

    OpenAIRE

    Derakhshandeh, K.; M. Nikmohammadi; A. Hosseinalizadeh

    2011-01-01

    Among the drug delivery strategies intended to increase the bioavailability of drugs, the use of polymeric biodegradable microcarriers has shown a significant degree of success.The purpose of this study was developing a polymeric drug delivery system for a model drug: furosemide, which belongs to class IV of BCS (low solubility and low permeability), intended to oral administration and improving the stability and intestinal absorption of the drug.To achieve this goal, furosemide loaded poly (...

  15. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  16. Biodegradation of polyethoxylated nonylphenols.

    Science.gov (United States)

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively. PMID:23936727

  17. Progress of biodegradable metals

    Institute of Scientific and Technical Information of China (English)

    Huafang Li; Yufeng Zheng; Ling Qin

    2014-01-01

    Biodegradable metals (BMs) are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompat-ibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  18. Biodegradable polymeric microcarriers with controllable porous structure for tissue engineering.

    Science.gov (United States)

    Shi, Xudong; Sun, Lei; Jiang, Jian; Zhang, Xiaolin; Ding, Wenjun; Gan, Zhihua

    2009-12-01

    Porous microspheres fabricated by biodegradable polymers show great potential as microcarriers for cell cultivation in tissue engineering. Herein biodegradable poly(DL-lactide) (PLA) was used to fabricate porous microspheres through a modified double emulsion solvent evaporation method. The influence of fabrication parameters, such as the stirring speed of the primary and secondary emulsion, the polymer concentration of the oil phase, and solvent type, as well as the post-hydrolysis treatment of the porous structure of the PLA microspheres are discussed. Good attachment and an active spread of MG-63 cells on the microspheres is observed, which indicates that the PLA microspheres with controllable porous structure are of great potential as cell delivery carriers for tissue engineering. PMID:19821453

  19. HYDRAULIC FRACTURING TO IMPROVE NUTRIENT AND OXYGEN DELIVERY FOR IN SITU BIORECLAMATION

    Science.gov (United States)

    The in situ delivery of nutrients and oxygen in soil is a serious problem in implementing in situ biodegradation. Current technology requires ideal site conditions to provide the remediating organisms with the nutrients and oxygen required for their metabolism, but...

  20. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    Science.gov (United States)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  1. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  2. Microcontainers - an oral drug delivery system for poorly soluble drugs

    DEFF Research Database (Denmark)

    Nielsen, Line Hagner; Petersen, Ritika Singh; Marizza, Paolo;

    of these studies was to fabricate microcontainers in either SU-8 or biodegradable poly-L-lactic acid (PLLA), and fill the microcontainers with poorly soluble drugs. Furthermore, the application of the microcontainers as an oral drug delivery system was investigated in terms of release, in situ......In oral delivery, it can sometimes be necessary to employ drug delivery systems to achieve targeted delivery to the intestine. Microcontainers are polymeric, cylindrical devices in the micrometer size range (Figure 1), and are suggested as a promising oral drug delivery system [1],[2]. The purpose...

  3. Development of a low pressure chromatographic flow system for monitoring the biodegradation of ofloxacin and ciprofloxacin

    OpenAIRE

    Santos, Inês C.; Mesquita, Raquel R. B.; Amorim, Catarina L.; Castro, Paula M. L.; Rangel, António O. S. S.

    2016-01-01

    In this work, we propose a simple low pressure chromatography method with a high throughput for monitoring the biodegradation of fluoroquinolones. Fluoroquinolones are a class of antibiotics that have been accumulating in the environment as a consequence of their release from different sources, namely hospital waste. It has been found that wastewater treatment plants are not able to completely remove this type of micro-pollutants and so, alternative solutions are necessary. Some biodegradatio...

  4. Adhesion of biocompatible and biodegradable micropatterned surfaces

    NARCIS (Netherlands)

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  5. Data on bone marrow stem cells delivery using porous polymer scaffold

    OpenAIRE

    Ramasatyaveni Geesala; Nimai Bar; Dhoke, Neha R.; Pratyay Basak; Amitava Das

    2015-01-01

    Low bioavailability and/or survival at the injury site of transplanted stem cells necessitate its delivery using a biocompatible, biodegradable cell delivery vehicle. In this dataset, we report the application of a porous biocompatible, biodegradable polymer network that successfully delivers bone marrow stem cells (BMSCs) at the wound site of a murine excisional splint wound model. In this data article, we are providing the additional data of the reference article “Porous polymer scaffold fo...

  6. Targeting Antibiotic Resistance.

    Science.gov (United States)

    Chellat, Mathieu F; Raguž, Luka; Riedl, Rainer

    2016-06-01

    Finding strategies against the development of antibiotic resistance is a major global challenge for the life sciences community and for public health. The past decades have seen a dramatic worldwide increase in human-pathogenic bacteria that are resistant to one or multiple antibiotics. More and more infections caused by resistant microorganisms fail to respond to conventional treatment, and in some cases, even last-resort antibiotics have lost their power. In addition, industry pipelines for the development of novel antibiotics have run dry over the past decades. A recent world health day by the World Health Organization titled "Combat drug resistance: no action today means no cure tomorrow" triggered an increase in research activity, and several promising strategies have been developed to restore treatment options against infections by resistant bacterial pathogens. PMID:27000559

  7. Antibiotics for uncomplicated diverticulitis

    DEFF Research Database (Denmark)

    Shabanzadeh, Daniel M; Wille-Jørgensen, Peer

    2012-01-01

    Diverticulitis is an inflammatory complication to the very common condition diverticulosis. Uncomplicated diverticulitis has traditionally been treated with antibiotics with reference to the microbiology, extrapolation from trials on complicated intra-abdominal infections and clinical experience....

  8. Biodegradation of glyphosate herbicide by Salinicoccus spp isolated from Qom Hoze-soltan lake, Iran

    Directory of Open Access Journals (Sweden)

    Yaser Sharifi

    2015-01-01

    Full Text Available Background: Glyphosate (N-phosphonomethyl Glycine is an organophosphorus pesticide with dangerous effects on the environment. In this study, the biodegradation of glyphosate herbicide by halophilic bacteria isolated from Qom Hoze-Soltan Lake has been investigated. Methods: After sampling and bacterial isolation, native halophilic strains grown in the presence of glyphosate at a wavelength of 660 nm and also the disappearance of the glyphosate in the plates at a wavelength of 220 nm were determined and the dominant bacteria were isolated. Biochemical, molecular (according to the 16S rRNA sequence, antibiotic, and the Minimum Inhibitory Concentration (MIC test was performed for the dominant bacteria. Analysis of the remaining glyphosate herbicide was performed by HPLC analysis after derivation with FMOC-Cl. Results: According to the results of the biochemical, antibiotic and molecular 16S rRNA tests, the native halophilic isolates with the ability to biodegrade glyphosate were gram positive cocci very similar to Salinicoccusspp. The results of HPLC showed that Salinicoccusspp is able to biodegrade glyphosate herbicide. Conclusion: The native bacteria in Qom Hoze-soltanlake, Iran can be used for biodegradation of glyphosate herbicide.

  9. Biodegradation of ciprofloxacin in water and soil and its effects on the microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Girardi, Cristobal, E-mail: cristobal.girardi-lavin@ufz.de [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Greve, Josephine [Minnesota State University, Mankato, MN 56001 8400 (United States); Lamshoeft, Marc [Institute of Environmental Research (INFU), TU Dortmund University, Otto-Hahn-Str. 6, NRW 44221 Dortmund (Germany); Fetzer, Ingo [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Microbiology, Permoserstrasse 15, 04318 Leipzig (Germany); Miltner, Anja [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany); Schaeffer, Andreas [Department of Environmental Biology and Chemodynamics, Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen (Germany); Kaestner, Matthias [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Biotechnology, Permoserstrasse 15, 04318 Leipzig (Germany)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Mineralisation of toxic pollutants can be higher in soil than in water. Black-Right-Pointing-Pointer Ciprofloxacin affects the microbial communities and activities in soil. Black-Right-Pointing-Pointer Toxicity of ciprofloxacin is reduced in soil due to sorption processes. Black-Right-Pointing-Pointer Despite the buffering capacity of soil, ciprofloxacin remains active. Black-Right-Pointing-Pointer Ciprofloxacin resistance can develop in soils contaminated with this antibiotic. - Abstract: While antibiotics are frequently found in the environment, their biodegradability and ecotoxicological effects are not well understood. Ciprofloxacin inhibits active and growing microorganisms and therefore can represent an important risk for the environment, especially for soil microbial ecology and microbial ecosystem services. We investigated the biodegradation of {sup 14}C-ciprofloxacin in water and soil following OECD tests (301B, 307) to compare its fate in both systems. Ciprofloxacin is recalcitrant to biodegradation and transformation in the aqueous system. However, some mineralisation was observed in soil. The lower bioavailability of ciprofloxacin seems to reduce the compound's toxicity against microorganisms and allows its biodegradation. Moreover, ciprofloxacin strongly inhibits the microbial activities in both systems. Higher inhibition was observed in water than in soil and although its antimicrobial potency is reduced by sorption and aging in soil, ciprofloxacin remains biologically active over time. Therefore sorption does not completely eliminate the effects of this compound.

  10. Biodegradation of ciprofloxacin in water and soil and its effects on the microbial communities

    International Nuclear Information System (INIS)

    Highlights: ► Mineralisation of toxic pollutants can be higher in soil than in water. ► Ciprofloxacin affects the microbial communities and activities in soil. ► Toxicity of ciprofloxacin is reduced in soil due to sorption processes. ► Despite the buffering capacity of soil, ciprofloxacin remains active. ► Ciprofloxacin resistance can develop in soils contaminated with this antibiotic. - Abstract: While antibiotics are frequently found in the environment, their biodegradability and ecotoxicological effects are not well understood. Ciprofloxacin inhibits active and growing microorganisms and therefore can represent an important risk for the environment, especially for soil microbial ecology and microbial ecosystem services. We investigated the biodegradation of 14C-ciprofloxacin in water and soil following OECD tests (301B, 307) to compare its fate in both systems. Ciprofloxacin is recalcitrant to biodegradation and transformation in the aqueous system. However, some mineralisation was observed in soil. The lower bioavailability of ciprofloxacin seems to reduce the compound's toxicity against microorganisms and allows its biodegradation. Moreover, ciprofloxacin strongly inhibits the microbial activities in both systems. Higher inhibition was observed in water than in soil and although its antimicrobial potency is reduced by sorption and aging in soil, ciprofloxacin remains biologically active over time. Therefore sorption does not completely eliminate the effects of this compound.

  11. Evaluation of antibiotic releasing porous polymethylmethacrylate space maintainers in an infected composite tissue defect model

    NARCIS (Netherlands)

    Spicer, P.P.; Shah, S.R.; Henslee, A.M.; Watson, B.M.; Kinard, L.A.; Kretlow, J.D.; Bevil, K.; Kattchee, L.; Bennett, G.N.; Demian, N.; Mende, K.; Murray, C.K.; Jansen, J.A.; Wong, M.E.; Mikos, A.G.; Kasper, F.K.

    2013-01-01

    This study evaluated the in vitro and in vivo performance of antibiotic-releasing porous polymethylmethacrylate (PMMA)-based space maintainers comprising a gelatin hydrogel porogen and a poly(dl-lactic-co-glycolic acid) (PLGA) particulate carrier for antibiotic delivery. Colistin was released in vit

  12. Poly (3-Hydroxyalkanoates: Biodegradable Plastics

    Directory of Open Access Journals (Sweden)

    Surbhi Jain

    2013-03-01

    Full Text Available During the 1920’s, a polyester called poly (3-hydroxybutyrate was discovered in bacterial cells. This compound, otherwise known as PHB, is part of a polyester family called polyhydroxyalkanoates (PHAs. Polyhydroxyalkanoates are used as an energy and carbon sto rage compound within certain bacterial cells. Polyhydroxyalkanoates (PHAs are thermoplastic, biodegradable polyesters synthesized by some bacteria from renewable carbon sources. However, their application is limited by high production cost. Polyhydroxyalkanoates (PHAs have attracted research and commercial interests worldwide because they can be used as biodegradable thermoplastics and also because they can be produced from renewable resources. This review will present an overview on synthesis and degradation of polyhydroxyalkanoates (PHAs, development as biodegradable plastics and its potential production from renewable resources such as palm oil products.

  13. Antibiotic induced meningitis.

    OpenAIRE

    1994-01-01

    Three patients with antibiotic induced meningitis, one following penicillin with seven episodes, are reported on--the first well documented description of penicillin induced meningitis. In this patient episodes of headache and nuchal rigidity appeared with and without CSF pleocytosis. Two patients had a total of five episodes of antibiotic induced meningitis after trimethoprim-sulphamethoxazole (co-trimoxazole) administration. The features common to all three patients were myalgia, confusion ...

  14. Antibiotic Precautions in Athletes

    OpenAIRE

    Fayock, Kristopher; Voltz, Matthew; Sandella, Bradley; Close, Jeremy; Lunser, Matthew; Okon, Joshua

    2014-01-01

    Context: Antibiotics are the mainstay of treatment for bacterial infections in patients of all ages. Athletes who maximally train are at risk for illness and various infections. Routinely used antibiotics have been linked to tendon injuries, cardiac arrhythmias, diarrhea, photosensitivity, cartilage issues, and decreased performance. Evidence Acquisition: Relevant articles published from 1989 to 2012 obtained through searching MEDLINE and OVID. Also, the Food and Drug Administration website w...

  15. [Analysis of antibiotic usage].

    Science.gov (United States)

    Balpataki, R; Balogh, J; Zelkó, R; Vincze, Z

    2001-01-01

    Economic analysis is founded on the assumption that resources are limited and that should be used in a way that maximizes the benefits gained. Pharmacoeconomics extends these assumptions to drug treatment. Therefore, a full pharmacoeconomic analysis must consider two or more alternative treatments and should be founded on measurement of incremental cost, incremental efficacy, and the value of successful outcome. Antibiotic policy based only on administrative restrictions is failed, instead of it disease formularies and infectologist consultation system are needed. Equally important are various programmes that encourage the cost-conscious use of the antibiotics chosen. Some of the methods evaluated in the literature include: streamlining from combination therapy to a single agent, early switching from parenteral to oral therapy, initiating treatment with oral agents, administering parenteral antibiotic at home from outset of therapy, and antibiotic streamlining programmes that are partnered with infectious disease physicians. The solution is the rational and adequate use of antibiotics, based on the modern theory and practice of antibiotic policy and infection control, that cannot be carried out without the activities of experts in this field. PMID:11769090

  16. Phenotypic Resistance to Antibiotics

    Directory of Open Access Journals (Sweden)

    Jose L. Martinez

    2013-04-01

    Full Text Available The development of antibiotic resistance is usually associated with genetic changes, either to the acquisition of resistance genes, or to mutations in elements relevant for the activity of the antibiotic. However, in some situations resistance can be achieved without any genetic alteration; this is called phenotypic resistance. Non-inherited resistance is associated to specific processes such as growth in biofilms, a stationary growth phase or persistence. These situations might occur during infection but they are not usually considered in classical susceptibility tests at the clinical microbiology laboratories. Recent work has also shown that the susceptibility to antibiotics is highly dependent on the bacterial metabolism and that global metabolic regulators can modulate this phenotype. This modulation includes situations in which bacteria can be more resistant or more susceptible to antibiotics. Understanding these processes will thus help in establishing novel therapeutic approaches based on the actual susceptibility shown by bacteria during infection, which might differ from that determined in the laboratory. In this review, we discuss different examples of phenotypic resistance and the mechanisms that regulate the crosstalk between bacterial metabolism and the susceptibility to antibiotics. Finally, information on strategies currently under development for diminishing the phenotypic resistance to antibiotics of bacterial pathogens is presented.

  17. [Prophylactic antibiotics in neurosurgery].

    Science.gov (United States)

    Iacob, G; Iacob, Simona; Cojocaru, Inimioara

    2007-01-01

    Because of a low risk of infection (around 2-3%), prophylactic use of antibiotics in neurosurgery is a controversial issue. Some neurosurgeons consider that there are strong arguments against the use of antimicrobials (promotion of antibiotic-resistant strains of bacteria, superinfection and adverse drug reactions) and meticulous aseptic techniques could be more usefully than prophylactic antibiotics. On the other hand, despite of being rare, the consequences of a neurosurgical infection can be dramatic and may result in a rapid death, caused by meningitis, cerebritis, abscess formation or sepsis. Clinical studies emphasized that the most important factors influencing the choice of antibiotic prophylaxis in neurosurgery is the patient's immune status, virulence of the pathogens and the type of surgery ("clean contaminated"--procedure that crosses the cranial sinuses, "clean non-implant"--procedure that does not cross the cranial sinuses, CSF shunt surgery, skull fracture). Prophylaxis has become the standard of care for contaminated and clean-contaminated surgery, also for surgery involving insertion of artificial devices. The antibiotic (first/second generation of cephalosporins or vancomycin in allergic patients) should recover only the cutaneous possibly contaminating flora (S. aureus, S. epidermidis) and should be administrated 30' before the surgical incision, intravenously in a single dose. Most studies pointed that identification of the risk factors for infections, correct asepsis and minimal prophylactic antibiotic regimen, help neurosurgeons to improve patient care and to decrease mortality without selecting resistant bacteria. PMID:18293694

  18. Pyomyositis after vaginal delivery.

    LENUS (Irish Health Repository)

    Gaughan, Eve

    2011-01-01

    Pyomyositis is a purulent infection of skeletal muscle that arises from haematogenous spread, usually with abscess formation. It can develop after a transient bacteraemia of any cause. This type of infection has never been reported before in the literature after vaginal delivery. A 34-year-old woman had progressive severe pain in the left buttock and thigh and weakness in the left lower limb day 1 post spontaneous vaginal delivery. MRI showed severe oedema of the left gluteus, iliacus, piriformis and adductor muscles of the left thigh and a small fluid collection at the left hip joint. She was diagnosed with pyomyositis. She had fever of 37.9°C immediately postpartum and her risk factors for bacteraemia were a mild IV cannula-associated cellulitis and labour itself. She required prolonged treatment with antibiotics before significant clinical improvement was noted.

  19. Strategies to Minimize Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Sang Hee Lee

    2013-09-01

    Full Text Available Antibiotic resistance can be reduced by using antibiotics prudently based on guidelines of antimicrobial stewardship programs (ASPs and various data such as pharmacokinetic (PK and pharmacodynamic (PD properties of antibiotics, diagnostic testing, antimicrobial susceptibility testing (AST, clinical response, and effects on the microbiota, as well as by new antibiotic developments. The controlled use of antibiotics in food animals is another cornerstone among efforts to reduce antibiotic resistance. All major resistance-control strategies recommend education for patients, children (e.g., through schools and day care, the public, and relevant healthcare professionals (e.g., primary-care physicians, pharmacists, and medical students regarding unique features of bacterial infections and antibiotics, prudent antibiotic prescribing as a positive construct, and personal hygiene (e.g., handwashing. The problem of antibiotic resistance can be minimized only by concerted efforts of all members of society for ensuring the continued efficiency of antibiotics.

  20. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  1. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...

  2. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  3. Micro fabrication of biodegradable polymer drug delivery devices

    DEFF Research Database (Denmark)

    Nagstrup, Johan

    . This has successfully been achieved by fabrication of micro container systems made of poly(Llactic acid) and polycaprolactone. To achieve this, polymer solutions have been developed using the theory of Hansen’s solubility parameters. The solutions are used to fabricate polymer films by spin coating...

  4. Hydrogel microspheres from biodegradable polymers as drug delivery systems

    Science.gov (United States)

    A series of hydrogel microspheres were prepared from pectin, a hydrophilic biopolymer, and zein, a hydrophobic biopolymer, at varying weight ratios. The hydrogel formulation was conducted in the presence of calcium or other divalent metal ions at room temperature under mild conditions. Studies of ...

  5. Biodegradable polymer systems with saccharide cores for targeted drug delivery

    Czech Academy of Sciences Publication Activity Database

    Kotrchová, Lenka; Etrych, Tomáš

    Bratislava: Young Scientists Council of Polymer Institute of Slovak Academy of Sciences, 2016. s. 49. ISBN 978-80-970923-8-2. [Bratislava Young Polymer Scientists workshop /6./ - BYPoS 2016. 14.03.2016-18.03.2016, Ždiar] R&D Projects: GA ČR(CZ) GA15-02986S; GA MŠk(CZ) LO1507 Institutional support: RVO:61389013 Keywords : cyclodextrins * star polymers * degradation Subject RIV: CD - Macromolecular Chemistry

  6. Ecological antibiotic policy.

    Science.gov (United States)

    Høiby, N

    2000-09-01

    Development of resistance to antibiotics is a major problem worldwide. The normal oropharyngeal flora, the intestinal flora and the skin flora play important roles in this development. Within a few days after the onset of antibiotic therapy, resistant Escherichia coli, Haemophilus influenzae and Staphylococcus epidermidis can be detected in the normal flora of volunteers or patients. Horizontal spread of the resistance genes to other species, e.g. Salmonella spp., Staphylococcus aureus and Streptococcus pneumoniae, occurs by conjugation or transformation. An ecologically sound antibiotic policy favours the use of antibiotics with little or no impact on the normal flora. Prodrug antibiotics which are not active against the bacteria in the mouth and the intestine (before absorption) and which are not excreted to a significant degree via the intestine, saliva or skin are therefore preferred. Prodrugs such as pivampicillin, bacampicillin, pivmecillinam and cefuroxime axetil are favourable from an ecological point of view. Experience from Scandinavia supports this, since resistance to mecillinam after 20 years of use is low (about 5%) and stable. PMID:11051626

  7. Advances in the Applications of Polyhydroxyalkanoate Nanoparticles for Novel Drug Delivery System

    OpenAIRE

    Young-Rok Kim; Anupama Shrivastav; Hae-Yeong Kim

    2013-01-01

    Drug delivery technology is emerging as an interdisciplinary science aimed at improving human health. The controlled delivery of pharmacologically active agents to the specific site of action at the therapeutically optimal rate and dose regimen has been a major goal in designing drug delivery systems. Over the past few decades, there has been considerable interest in developing biodegradable drug carriers as effective drug delivery systems. Polymeric materials from natural sources play an imp...

  8. Advanced Materials and Processing for Drug Delivery: The Past and the Future

    OpenAIRE

    Zhang, Ying; Chan, Hon Fai; Leong, Kam W.

    2012-01-01

    Design and synthesis of efficient drug delivery systems are of vital importance for medicine and healthcare. Materials innovation and nanotechnology have synergistically fueled the advancement of drug delivery. Innovation in material chemistry allows the generation of biodegradable, biocompatible, environment-responsive, and targeted delivery systems. Nanotechnology enables control over size, shape and multi-functionality of particulate drug delivery systems. In this review, we focus on the m...

  9. The multifaceted roles of antibiotics and antibiotic resistance in nature

    Directory of Open Access Journals (Sweden)

    Saswati eSengupta

    2013-03-01

    Full Text Available Antibiotics are chemotherapeutic agents, which have been a very powerful tool in the clinical management of bacterial diseases since the 1940s. However, benefits offered by these magic bullets have been substantially lost in subsequent days following the widespread emergence and dissemination of antibiotic resistant strains. While it is obvious that excessive and imprudent use of antibiotics significantly contributes to the emergence of resistant strains, antibiotic-resistance is also observed in natural bacteria of remote places unlikely to be impacted by human intervention. Both antibiotic biosynthetic genes and resistance-conferring genes have been known to evolve billions of years ago, long before clinical use of antibiotics. Hence it appears that antibiotics and antibiotics resistance determinants have some other roles in nature, which often elude our attention because of overemphasis on the therapeutic importance of antibiotics and the crisis imposed by the antibiotic-resistance in pathogens. In the natural milieu, antibiotics are often found to be present in subinhibitory concentrations acting as signalling molecules supporting quorum sensing and biofilm formation. They also play an important role in the production of virulence factors and influence host-parasite interactions (e.g., phagocytosis, adherence to the target cell and so on. The evolutionary and ecological aspects of antibiotics and antibiotic-resistance in the naturally occurring microbial community are little understood. Therefore, the actual role of antibiotics in nature warrants in-depth investigations. Studies on such an intriguing behaviour of the microorganisms promise insight into the intricacies of the microbial physiology and are likely to provide some lead in controlling the emergence and subsequent dissemination of antibiotic resistance. This article highlights some of the recent findings on the role of antibiotics and genes that confer resistance to antibiotics in

  10. Cystic fibrosis, intravenous antibiotics, and home therapy.

    Science.gov (United States)

    Hammond, L J; Caldwell, S; Campbell, P W

    1991-01-01

    The survival rate of patients with cystic fibrosis has improved considerably in the last 20 years. Although not all of the factors accounting for this change are understood, aggressive nutritional management and treatment of pulmonary exacerbations certainly play a role. Home intravenous (IV) antibiotic delivery for pulmonary exacerbation has proved to be as effective as hospital treatment and offers significant advantages to the patient and family. This article examines the microbiology of pulmonary infections in patients with cystic fibrosis, as well as antimicrobial therapy, methods of IV administration, home IV therapy, and the nurse practitioner's role in this home program in the future. PMID:1990112

  11. NANOTECHNOLOGICAL SOLUTION FOR IMPROVING THE ANTIBIOTIC EFFICIENCY AGAINST BIOFILMS DEVELOPED BY GRAM-NEGATIVE BACTERIAL STRAINS

    Directory of Open Access Journals (Sweden)

    Keng-Shiang Huang

    2013-03-01

    Full Text Available At present bacteria involved in biofilm associated infections display the highest rates of antibiotic resistance among pathogenic bacteria, which made that treatment options to be limited, and determined the researchers to find out alternative treatments to antibiotics. In the recent years nanomaterials gained much attention in medicine, particularly in the fight to bacteria resistant to antibiotics by acting as drug delivery devices. Magnetic iron oxide nanoparticles (MNPs have raised much interest during the recent years due to their potential applications in medicine. In the present study we synthesized MNPd functionalized with antibiotics for the study of their antimicrobial and anti-biofilm properties against Escherichia coli and Pseudomonas aeruginosa, two Gram-negative bacteria, frequently resistant to antibiotics, involved in biofilm infections in order to investigate their capacity to serve as potential drug delivery systems in the fight to these important opportunist pathogens.

  12. Biobased and biodegradable polymer nanocomposites

    Science.gov (United States)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  13. [Antibiotical prophylaxy in gynecology].

    Science.gov (United States)

    Záhumenský, J; Menzlová, E; Zmrhal, J; Kučera, E

    2013-08-01

    Gynecological surgery is considered to be clear with possible contamination by gram-positive cocci from the skin, gram-negatives from the perineum or groins or polymicrobial biocenosis from vagina, depending on the surgical approach. Antibiotical prophylaxy enforces the natural mechanisms of immunity and helps to exclude present infection. There were presented many studies comparing useful effect of prophylaxis in gynecological surgery. The benefits of antibiotical prophylaxy before IUD insertion, before the cervical surgery and before hysteroscopies were not verified. On the other hand the prophylaxy of vaginal surgery including vaginal hysterectomy decreases the number of postoperative febrile complications. The positive influence of prophylaxis before the simple laparoscopy and laparoscopy without bowel injury or the opening of the vagina was not evidently verified. In abdominal hysterectomy the antibiotical prophylaxy decreases the incidence of postoperative complications significantly. The administration of 2 g of cefazolin can be recommended. In procedures taking more than 3 hours the repeated administration of cefazolin is suitable. New urogynecological procedures, using mesh implants, were not sufficiently evaluated as for postoperative infections and the posible antibiotical effect. The presence of implant in possibly non sterile area should be considered as high risc of postoperative complications. PMID:24040985

  14. Antibiotics in interventional radiology

    International Nuclear Information System (INIS)

    The range and number of interventional procedures is rapidly increasing each year. A major complication associated with many procedures is infection, which can result in serious adverse outcomes for the patient. Consequently, antibiotics are amongst the most common pharmaceuticals used by the interventionist, particularly for non-vascular procedures, yet almost no randomized controlled trial data exist to inform our decision when formulating appropriate antibiotic prophylaxis regimens. The purpose of this review is to provide an update on the utilization of antibiotics for common interventional radiology procedures, focusing on timing and duration of antibiotic prophylaxis. - Highlights: • Prophylaxis when necessary should be given immediately prior to the procedure for optimum effect. • Where possible single agents with a narrow spectrum of activity should be used. • Account should be taken of the clinical circumstances of the patient, including surgical history. • Continuous review of agents is necessary, ideally with input from the local microbiology department. • The importance of maximum sterile precautions cannot be overstated

  15. BIODEGRADABLE COATING FROM AGATHIS ALBA

    Directory of Open Access Journals (Sweden)

    NORYAWATI MULYONO

    2012-11-01

    Full Text Available The adhesive property of copal makes it as a potential coating onto aluminum foil to replace polyethylene. This research aimed to develop copal-based coating. The coating was prepared by extracting the copal in ethyl acetate and dipping the aluminium foil in ethyl acetate soluble extract of copal. The characterization of coating included its thickness, weight, thermal and chemical resistance, and biodegradation. The results showed that the coating thickness and weight increased as the copal concentration and dipping frequency increased. Thermal resistance test showed that the coating melted after being heated at 110°C for 30 min. Copal-based coating wasresistant to acidic solution (pH 4.0, water, and coconut oil, but was deteriorated in detergent 1% (w/v and basic solution (pH 10.0. Biodegradability test using Pseudomonas aeruginosa showed weight reduction of 76.82% in 30 days.

  16. Treatment Utility of Postpartum Antibiotics in Chorioamnionitis Study.

    Science.gov (United States)

    Shanks, Anthony L; Mehra, Suwan; Gross, Gil; Colvin, Ryan; Harper, Lorie M; Tuuli, Methodius G

    2016-07-01

    Objective To determine if postpartum antibiotics are necessary for patients with chorioamnionitis after a cesarean delivery (CD). Study Design Multicenter randomized controlled trial. Laboring patients with singleton gestations and chorioamnionitis who underwent CD were eligible. Patients were treated with ampicillin and gentamicin per standard protocol, then given clindamycin prior to skin incision. Patients were randomized to either postpartum antibiotic prophylaxis or no treatment following delivery. The primary outcome was the rate of endometritis. Assuming a 30% risk of endometritis in patients with chorioamnionitis who undergo CD, 119 patients per arm would be required to detect a 50% decrease in endometritis. Results The trial was stopped for futility following a planned interim analysis after 80 patients were randomized. There was no difference in the rate of the primary outcome between the two groups (9.8 vs. 7.7%, relative risk [RR]: 1.27; 95% confidence interval [CI]: 0.30, 5.31). A meta-analysis comparing post-CD antibiotics versus no treatment did not find a statistically significant difference between the groups (16.7 vs. 12.0%, pooled RR: 1.43; 95% CI: 0.72, 2.84). Conclusion Additional postpartum antibiotics do not decrease the rate of endometritis in patients with chorioamnionitis who undergo CD. The current preoperative antibiotic regimen including clindamycin should remain the standard of care in these patients. PMID:26890440

  17. Biodegradation of Polycyclic Aromatic Hydrocarbons

    OpenAIRE

    DEMİR, İsmail; DEMİRBAĞ, Zihni

    1999-01-01

    Polycylic aromatic hydrocarbons (PAHs), such as petroleum and petroleum derivatives, are widespread organic pollutants entering the environment, chiefly, through oil spills and incomplete combustion of fossil fuels. Since most PAHs are persist in the environment for a long period of time and bioaccumulate, they cause environmental pollution and effect biological equilibrium dramatically. Biodegradation of some PAHs by microorganisms has been biochemically and genetically investigated. Ge...

  18. Polysaccharide-based Noncovalent Assembly for Targeted Delivery of Taxol.

    Science.gov (United States)

    Yang, Yang; Zhang, Ying-Ming; Chen, Yong; Chen, Jia-Tong; Liu, Yu

    2016-01-01

    The construction of synthetic straightforward, biocompatible and biodegradable targeted drug delivery system with fluorescent tracking abilities, high anticancer activities and low side effects is still a challenge in the field of biochemistry and material chemistry. In this work, we constructed targeted paclitaxel (Taxol) delivery nanoparticles composed of permethyl-β-cyclodextrin modified hyaluronic acid (HApCD) and porphyrin modified paclitaxel prodrug (PorTaxol), through host-guest and amphiphilic interactions. The obtained nanoparticles (HATXP) were biocompatible and enzymatic biodegradable due to their hydrophilic hyaluronic acid (HA) shell and hydrophobic Taxol core, and exhibited specific targeting internalization into cancer cells via HA receptor mediated endocytosis effects. The cytotoxicity experiments showed that the HATXP exhibited similar anticancer activities to, but much lower side effects than commercial anticancer drug Taxol. The present work would provide a platform for targeted paclitaxel drug delivery and a general protocol for the design of advanced multifunctional nanoscale biomaterials for targeted drug/gene delivery. PMID:26759029

  19. Biodegradable lubricants for road vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Denmark Technical Univ., Lyngby (Denmark). Dept. of Mechanical Engineering

    2004-07-01

    This presentation outlined the characteristics of biolubricants and their use in vehicles. Experiments with compression ignition (CI) and spark ignition (SI) engines were also presented. Biolubes can be used in 4-stroke and 2-stroke engines, bearing compressors and hydraulic equipment. Studies have shown that biolubes do not cause unusual engine wear. They are produced from biomass, with the base material being vegetable oils and synthetic esters. Conventional lubricants are produced from fossil fuels, with the base material being mineral oils, polyglycol or synthetic ester. This presentation rated the characteristics of various lubricants in terms of viscosity temperature behaviour, low temperature behaviour, liquid range, oxidation stability, thermal stability, volatility, fire resistance, hydrolytic stability, corrosion protection, seal material compatibility, paints compatibility, miscibility with mineral oil, solubility of additives, lubricating properties, toxicity, and biodegradability. The environmental impacts of biolubes regarding emissions of carbon dioxide, nitrous oxide and particulate matter were discussed along with the impact of combining biolubes with alternative fuels. The future beneficial applications include outboard engines, off road vehicle engines and road vehicle engines. Currently, vegetable oil based biolubricants are 2 to 3 times more expensive than mineral based oils, and synthetic lubricants are even more expensive. It was suggested that future studies should examine the biodegradability of used lubricants, the performance of biodegradable lubricants, alternative fuels and fuel economy. tabs., figs.

  20. Engineering Flame Retardant Biodegradable Nanocomposites

    Science.gov (United States)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  1. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  2. Recent Advancement of Chitosan-Based Nanoparticles for Oral Controlled Delivery of Insulin and Other Therapeutic Agents

    OpenAIRE

    Chaudhury, Anumita; Das, Surajit

    2010-01-01

    Nanoparticles composed of naturally occurring biodegradable polymers have emerged as potential carriers of various therapeutic agents for controlled drug delivery through the oral route. Chitosan, a cationic polysaccharide, is one of such biodegradable polymers, which has been extensively exploited for the preparation of nanoparticles for oral controlled delivery of several therapeutic agents. In recent years, the area of focus has shifted from chitosan to chitosan derivatized polymers for th...

  3. Environmental pollution by antibiotics and by antibiotic resistance determinants

    International Nuclear Information System (INIS)

    Antibiotics are among the most successful drugs used for human therapy. However, since they can challenge microbial populations, they must be considered as important pollutants as well. Besides being used for human therapy, antibiotics are extensively used for animal farming and for agricultural purposes. Residues from human environments and from farms may contain antibiotics and antibiotic resistance genes that can contaminate natural environments. The clearest consequence of antibiotic release in natural environments is the selection of resistant bacteria. The same resistance genes found at clinical settings are currently disseminated among pristine ecosystems without any record of antibiotic contamination. Nevertheless, the effect of antibiotics on the biosphere is wider than this and can impact the structure and activity of environmental microbiota. Along the article, we review the impact that pollution by antibiotics or by antibiotic resistance genes may have for both human health and for the evolution of environmental microbial populations. - The article reviews the current knowledge on the effects that pollution by antibiotics and antibiotic resistance genes may have for the microbiosphere.

  4. Biodegradation of high molecular weight polylactic acid

    OpenAIRE

    Stloukal, Petr; Koutný, Marek; Sedlařík, Vladimír; Kucharczyk, Pavel

    2012-01-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite e...

  5. Biodegradable materials as foundry moulding sands binders

    OpenAIRE

    K. Major-Gabryś

    2015-01-01

    The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved abilit...

  6. [Pregnancy and breast feeding: antibiotics, irrigation and pastes].

    Science.gov (United States)

    Fatori Popovic, Sandra; Lübbers, Heinz-Theo; von Mandach von Mandach, Ursula

    2016-01-01

    The aim of this paper is to show aspects of dental treatment in pregnancy. The reader should gain security in the election of the proper drugs for antibiotic therapy and rinsing solutions. Antibiotics as penicillins are the first choice in case of dental infections in pregnancy. In allergic patients, macrolides may be an alternative. Wound and mouth rinsing solutions containing chlorhexidine should be preferred in pregnancy. Ledermix(®) in endodontic treatment should be avoided in the pregnant woman. Solcoseryl(®) can be used for wound healing. Elective dental procedures should be postponed after delivery and after lactation period. PMID:27277144

  7. Biodegradable materials as foundry moulding sands binders

    Directory of Open Access Journals (Sweden)

    K. Major - Gabryś

    2015-07-01

    Full Text Available The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved ability to reclamation as well as in accelerated biodegradation of binding material leftovers of mechanical reclamation.

  8. Repair of osteochondral defects with biodegradable hydrogel composites encapsulating marrow mesenchymal stem cells in a rabbit model.

    NARCIS (Netherlands)

    Guo, X.; Park, H.; Young, S.; Kretlow, J.D.; Beucken, J.J.J.P. van den; Baggett, L.S.; Tabata, Y.; Kasper, F.K.; Mikos, A.G.; Jansen, J.A.

    2010-01-01

    This work investigated the delivery of marrow mesenchymal stem cells (MSCs), with or without the growth factor transforming growth factor-beta1 (TGF-beta1), from biodegradable hydrogel composites on the repair of osteochondral defects in a rabbit model. Three formulations of oligo(poly(ethylene glyc

  9. Inhaled Antibiotics for Gram-Negative Respiratory Infections.

    Science.gov (United States)

    Wenzler, Eric; Fraidenburg, Dustin R; Scardina, Tonya; Danziger, Larry H

    2016-07-01

    Gram-negative organisms comprise a large portion of the pathogens responsible for lower respiratory tract infections, especially those that are nosocomially acquired, and the rate of antibiotic resistance among these organisms continues to rise. Systemically administered antibiotics used to treat these infections often have poor penetration into the lung parenchyma and narrow therapeutic windows between efficacy and toxicity. The use of inhaled antibiotics allows for maximization of target site concentrations and optimization of pharmacokinetic/pharmacodynamic indices while minimizing systemic exposure and toxicity. This review is a comprehensive discussion of formulation and drug delivery aspects, in vitro and microbiological considerations, pharmacokinetics, and clinical outcomes with inhaled antibiotics as they apply to disease states other than cystic fibrosis. In reviewing the literature surrounding the use of inhaled antibiotics, we also highlight the complexities related to this route of administration and the shortcomings in the available evidence. The lack of novel anti-Gram-negative antibiotics in the developmental pipeline will encourage the innovative use of our existing agents, and the inhaled route is one that deserves to be further studied and adopted in the clinical arena. PMID:27226088

  10. In vitro and in vivo evaluation of biodegradable embolic microspheres with tunable anticancer drug release.

    Science.gov (United States)

    Weng, Lihui; Rostamzadeh, Parinaz; Nooryshokry, Navid; Le, Hung C; Golzarian, Jafar

    2013-06-01

    Natural polymer-derived materials have attracted increasing interest in the biomedical field. Polysaccharides have obvious advantages over other polymers employed for biomedical applications due to their exceptional biocompatibility and biodegradability. None of the spherical embolic agents used clinically is biodegradable. In the current study, microspheres prepared from chitosan and carboxymethyl cellulose (CMC) were investigated as a biodegradable embolic agent for arterial embolization applications. Aside from the enzymatic degradability of chitosan units, the cross-linking bonds in the matrix, Schiff bases, are susceptible to hydrolytic cleavage in aqueous conditions, which would overcome the possible shortage of enzymes inside the arteries. The size distribution, morphology, water retention capacity and degradability of the microspheres were found to be affected by the modification degree of CMC. An anticancer drug, doxorubicin, was successfully incorporated into these microspheres for local release and thus for killing cancerous cells. These microspheres demonstrated controllable degradation time, variable swelling and tunable drug release profiles. Co-culture with human umbilical vein endothelial cells revealed non-cytotoxic nature of these microspheres compared to monolayer control (P>0.95). In addition, a preliminary study on the in vivo degradation of the microspheres (100-300μm) was performed in a rabbit renal embolization model, which demonstrated that the microspheres were compatible with microcatheters for delivery, capable of occluding the arteries, and biodegradable inside arteries. These microspheres with biodegradability would be promising for embolization therapies. PMID:23419554

  11. Pneumococcal resistance to antibiotics.

    OpenAIRE

    Klugman, K P

    1990-01-01

    The geographic distribution of pneumococci resistant to one or more of the antibiotics penicillin, erythromycin, trimethoprim-sulfamethoxazole, and tetracycline appears to be expanding, and there exist foci of resistance to chloramphenicol and rifampin. Multiply resistant pneumococci are being encountered more commonly and are more often community acquired. Factors associated with infection caused by resistant pneumococci include young age, duration of hospitalization, infection with a pneumo...

  12. Antibiotics in dental practice

    OpenAIRE

    2007-01-01

    The oral cavity and it surrounding tissue are habitats for many bacteria. Therefore a rationale for the use of antibacterial agents rises. During my time as a dental student, me often meet conditions were antibiotics are pointed out as the treatment of chose, as indicated or not recommended. According to Norwegian drug regulations (Tørisen 2007) dentists have: The right to requisition necessary medical agents in connection with dental treatment and prevention and treatment of diseases in the...

  13. Enhanced Crude Oil Biodegradation in a Two-liquid Phase Partitioning Bioreactor

    OpenAIRE

    Ismail, Z. Z.; Abdulrazzak, I. A.

    2015-01-01

    The biodegradation of crude oil at relatively high concentrations in an aquatic environment is constrained by the inherent toxicity of crude oil. In this study, a new application of an aqueous- organic two-liquid phase partitioning bioreactor (TLPPB) was developed to degrade high concentrations of crude oil up to 5000 mg L–1. Silicon oil was selected as the sequestering organic phase to control the delivery of crude oil in aqueous phase by absorbing, and subsequently releasing the crude oi...

  14. Synthesis and biocompatibility of a biodegradable and functionalizable thermo-sensitive hydrogel

    OpenAIRE

    Sinha, Mantosh K.; Gao, Jin; Stowell, Chelsea E. T.; Wang, Yadong

    2015-01-01

    Injectable thermal gels are a useful tool for drug delivery and tissue engineering. However, most thermal gels do not solidify rapidly at body temperature (37°C). We addressed this by synthesizing a thermo-sensitive, rapidly biodegrading hydrogel. Our hydrogel, poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane) (EPSHU), is an ABA block copolymer comprising A, methoxy poly ethylene glycol group and B, poly (propanol L-serinate hexamethylene urethane). EPSHU was characteriz...

  15. Scalable Method to Produce Biodegradable Nanoparticles that Rapidly Penetrate Human Mucus

    OpenAIRE

    Xu, Qingguo; Boylan, Nicholas J; Cai, Shutian; Miao, Bolong; Patel, Himatkumar; Hanes, Justin

    2013-01-01

    Mucus typically traps and rapidly removes foreign particles from the airways, gastrointestinal tract, nasopharynx, female reproductive tract and the surface of the eye. Nanoparticles capable of rapid penetration through mucus can potentially avoid rapid clearance, and open significant opportunities for controlled drug delivery at mucosal surfaces. Here, we report an industrially scalable emulsification method to produce biodegradable mucus-penetrating particles (MPP). The emulsification of di...

  16. (3-Aminopropyl)-4-methylpiperazine End-capped Poly(1,4-butanediol diacrylate-co-4-amino-1-butanol)-based Multilayer Films for Gene Delivery

    OpenAIRE

    Li, Cuicui; Tzeng, Stephany Y.; Tellier, Liane E.; Green, Jordan J.

    2013-01-01

    Biodegradable polyelectrolyte surfaces for gene delivery were created through electrospinning of biodegradable polycations combined with iterative solution-based multilayer coating. Poly(β-amino ester) (PBAE) poly(1,4-butanediol diacrylate-co-4-amino-1-butanol) end-capped with 1-(3-aminopropyl)-4-methylpiperazine was utilized due to its ability to electrostatically interact with anionic molecules like DNA, its biodegradability, and its low cytotoxicity. A new DNA release system was developed ...

  17. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...... order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  18. Optimizing Antibiotic Use in Nursing Homes Through Antibiotic Stewardship.

    Science.gov (United States)

    Sloane, Philip D; Huslage, Kirk; Kistler, Christine E; Zimmerman, Sheryl

    2016-01-01

    Antibiotic stewardship is becoming a requirement for nursing homes. Programs should be interdisciplinary and multifaceted; should have support from nursing home administrators; and should aim to promote antibiotics only when needed, not just in case. Recommended components include use of evidence-based guidelines; ongoing monitoring of antibiotic prescriptions, cultures, and study results; monitoring of health outcomes; use of nursing home-specific antibiograms; regular reporting and feedback to medical providers and nurses; and education of residents and families. PMID:27621341

  19. Antibiotic-resistant acne: getting under the skin.

    Science.gov (United States)

    Sinha, Mau; Sadhasivam, Suresh; Bhattacharyya, Anamika; Jain, Shilpi; Ghosh, Shamik; Arndt, Kenneth A; Dover, Jeffrey S; Sengupta, Shiladitya

    2016-06-01

    Propionibacterium acnes is a key pathogenic factor in the development of acne. Antibiotics are the first choice of treatment for mild-to-moderate, mixed, papular/pustular, and moderate nodular acne, and an alternative choice in severe, nodular/conglobate acne. The emergence of resistance to the currently available antibiotics poses a serious set-back to this algorithm, and the reduced arsenal can diminish efficacy of treatment. This emerging situation should catalyze innovations in dermatology; for example, newer drugs and technologies such as next-generation antibiotics with excellent potency and low propensity to develop resistance, rapid diagnostic platforms to select responders and nonresponders, and delivery technologies that target the bacteria. Such innovations can dramatically expand the arsenal for dermatologists in the management of acne. PMID:27416310

  20. Biodegradation and toxicological evaluation of lubricant oils

    Directory of Open Access Journals (Sweden)

    Ivo Shodji Tamada

    2012-12-01

    Full Text Available The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei, arugula seeds (Eruca sativa and lettuce seeds (Lactuca sativa, with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days of biodegradation. The used lubricant oil was proved very toxic in all the tests and even after biodegradation its toxicity was high. The mineral and synthetic oils were biodegraded efficiently in the soil although their toxicity did not disappear completely after 180 days.

  1. Protein-Based Nanomedicine Platforms for Drug Delivery

    Energy Technology Data Exchange (ETDEWEB)

    Ma Ham, Aihui; Tang, Zhiwen; Wu, Hong; Wang, Jun; Lin, Yuehe

    2009-08-03

    Drug delivery systems have been developed for many years, however some limitations still hurdle the pace of going to clinical phase, for example, poor biodistribution, drug molecule cytotoxicity, tissue damage, quick clearance from the circulation system, solubility and stability of drug molecules. To overcome the limitations of drug delivery, biomaterials have to be developed and applied to drug delivery to protect the drug molecules and to enhance the drug’s efficacy. Protein-based nanomedicine platforms for drug delivery are platforms comprised of naturally self-assembled protein subunits of the same protein or a combination of proteins making up a complete system. They are ideal for drug delivery platforms due to their biocompatibility and biodegradability coupled with low toxicity. A variety of proteins have been used and characterized for drug delivery systems including the ferritin/apoferritin protein cage, plant derived viral capsids, the small Heat shock protein (sHsp) cage, albumin, soy and whey protein, collagen, and gelatin. There are many different types and shapes that have been prepared to deliver drug molecules using protein-based platforms including the various protein cages, microspheres, nanoparticles, hydrogels, films, minirods and minipellets. There are over 30 therapeutic compounds that have been investigated with protein-based drug delivery platforms for the potential treatment of various cancers, infectious diseases, chronic diseases, autoimmune diseases. In protein-based drug delivery platforms, protein cage is the most newly developed biomaterials for drug delivery and therapeutic applications. Their uniform sizes, multifunctions, and biodegradability push them to the frontier for drug delivery. In this review, the recent strategic development of drug delivery has been discussed with a special emphasis upon the polymer based, especially protein-based nanomedicine platforms for drug delivery. The advantages and disadvantages are also

  2. Antibiotic prevention of postcataract endophthalmitis

    DEFF Research Database (Denmark)

    Kessel, Line; Flesner, Per; Andresen, Jens;

    2015-01-01

    Endophthalmitis is one of the most feared complications after cataract surgery. The aim of this systematic review was to evaluate the effect of intracameral and topical antibiotics on the prevention of endophthalmitis after cataract surgery. A systematic literature review in the MEDLINE, CINAHL......, Cochrane Library and EMBASE databases revealed one randomized trial and 17 observational studies concerning the prophylactic effect of intracameral antibiotic administration on the rate of endophthalmitis after cataract surgery. The effect of topical antibiotics on endophthalmitis rate was reported by one...... with the use of intracameral antibiotic administration of cefazolin, cefuroxime and moxifloxacin, whereas no effect was found with the use of topical antibiotics or intracameral vancomycin. Endophthalmitis occurred on average in one of 2855 surgeries when intracameral antibiotics were used compared to...

  3. Antibiotics in otorhinolaryngology practice

    Directory of Open Access Journals (Sweden)

    Stefan-Mikić Sandra

    2002-01-01

    Full Text Available Introduction This study investigated utilization of antibacterial agents at the Ear, Nose and Throat Department of the Outpatient Service of the Health Center Novi Sad - Liman and at the Ear, Nose and Throat Clinic of the Clinical Center Novi Sad, in the period February - March 2001. Material and methods All antibacterial agents were classified as group J, regarding Anatomic-Therapeutic-Chemical Classification. Data on drug utilization were presented in Defined Daily Doses (DDD. Patients who were under observation were all treated with antibiotics. Results In regard to prescribed treatment in the Ear, Nose and Throat Department of the Outpatient Service of the Health Center Novi Sad - Liman, most outpatients were treated with macrolide antibiotics - in 26.21%; combination of penicillin and beta-lactamase inhibitors in 20.83% and pyranosides in 16.12%. At the Ear, Nose and Throat Clinic of the Clinical Center Novi Sad, macrolides and lincosamines were most frequently used - in 20.46%; cephalosporins in 19.87% and penicillins susceptible to beta-lactamase in 18.85%. It is extremely positive and in agreement with current pharmacotherapeutic principles that in both institutions peroral ampicillins have not been prescribed. Aminoglycosides have been prescribed in less than 1% of patients of the Ear, Nose and Throat Department of the Outpatient Service of the Health Center Novi Sad - Liman, whereas they were much more frequently prescribed at the Ear, Nose and Throat Clinic of the Clinical Center Novi Sad - in 11.25%. Although there is a positive postantibiotic effect in regard to these antibiotics and it is recommended to use them once a day, in both examined institutions aminoglycosides were given twice a day. In regard to bacterial identification it was done in 80.76% of patients of the Ear, Nose and Throat Department of the Outpatient Service of the Health Center Novi Sad - Liman, while in the Ear, Nose and Throat Clinic of the Clinical Center

  4. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  5. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  6. Antibiotics and oral contraceptives.

    Science.gov (United States)

    Rubin, D F

    1981-04-01

    Dermatologists often prescribe oral tetracycline for the control of acne, primarily, and to a much lesser extent, for the treatment of cutaneous infections. A number of the patients taking tetracycline are also taking birth control pills. A recent article in the British Medical Journal (1980;1:293) indicates that this combination can lead to a failure of the (OC) oral contraceptive. Such failure had been associated with ampicillin as well. It is believed that the mechanism for this was the disturbance in normal gut flora, with consequent effects on bacterial hydrolysis of steroid conjugates. This would interrupt the enterohepatic circulation of contraceptive steroids, resulting in a less than normal concentration of circulating steroids. It was recommended that women taking low-dose OCs take extra precautions against pregnancy during any cycle in which antibiotics are given. In regard to our care of and responsibilities to our patients, and in an era when malpractice suits for all types of reasons are more common, it certainly behooves dermatologists to recognize and be concerned about this potential consequence of prescribing oral antibiotics. PMID:7212735

  7. Development of nanoantibiotic delivery system using cockle shell-derived aragonite nanoparticles for treatment of osteomyelitis

    Directory of Open Access Journals (Sweden)

    Saidykhan L

    2016-02-01

    Full Text Available Lamin Saidykhan,1 Md Zuki Bin Abu Bakar,2 Yaya Rukayadi,1,3 Aminu Umar Kura,4 Saiful Yazan Latifah5 1Microbiology Unit, Laboratory of Natural Products, Institute of Bioscience, 2Laboratory of Anatomy and Histology, Department of Veterinary Preclinical Sciences, Faculty of Veterinary Medicine, 3Department of Food Science, Faculty of Food Science and Technology, 4Vaccine and Immunotherapeutics Laboratory Unit, Institute of Bioscience, 5Department of Biomedical Science, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia Abstract: A local antibiotic delivery system (LADS with biodegradable drug vehicles is recognized as the most effective therapeutic approach for the treatment of osteomyelitis. However, the design of a biodegradable LADS with high therapeutic efficacy is too costly and demanding. In this research, a low-cost, facile method was used to design vancomycin-loaded aragonite nanoparticles (VANPs with the aim of understanding its potency in developing a nanoantibiotic bone implant for the treatment of osteomyelitis. The aragonite nanoparticles (ANPs were synthesized from cockle shells by a hydrothermal approach using a zwitterionic surfactant. VANPs were prepared using antibiotic ratios of several nanoparticles, and the formulation (1:4 with the highest drug-loading efficiency (54.05% was used for physicochemical, in vitro drug release, and biological evaluation. Physiochemical characterization of VANP was performed by using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray powder diffraction, and Zetasizer. No significant differences were observed between VANP and ANP in terms of size and morphology as both samples were cubic shaped with sizes of approximately 35 nm. The Fourier transform infrared spectroscopy of VANP indicated a weak noncovalent interaction between ANP and vancomycin, while the zeta potential values were slightly increased from -19

  8. Cyclodextrin nanoassemblies: a promising tool for drug delivery.

    Science.gov (United States)

    Bonnet, Véronique; Gervaise, Cédric; Djedaïni-Pilard, Florence; Furlan, Aurélien; Sarazin, Catherine

    2015-09-01

    Among the biodegradable and nontoxic compounds that can form nanoparticles for drug delivery, amphiphilic cyclodextrins are very promising. Apart from ionic cyclodextrins, which have been extensively studied and reviewed because of their application in gene delivery, our purpose is to provide a clear description of the supramolecular assemblies of nonionic amphiphilic cyclodextrins, which can form nanoassemblies for controlled drug release. Moreover, we focus on the relationship between their structure and physicochemical characteristics, which is crucial for self assembly and drug delivery. We also highlight the importance of the nanoparticle technology preparation for the stability and application of this nanodevice. PMID:26037681

  9. Ecological risk assessment of antibiotics treated by radioactive rays

    International Nuclear Information System (INIS)

    Removal efficiency of pharmaceuticals with various treatment methods and their toxicological tests were conducted to estimate the variations in toxicity using various organisms. The toxicity of target compounds on various aqueous organisms were conducted. Also, the removal efficiency of gamma-irradiated target compounds and their toxicity change was estimated. Furthermore, gamma-treatment was compared with degradation test with activated sludge and UV treatment due to decide the possibility of gamma-radiation as an alternative decomposing technique for the target compounds. Finally, the removal efficiency and estrogenicity of estrogenic compounds in gamma irradiated wastewater effluent was conducted. As a result, gamma radiation was an effective method for decomposing antibiotics and estrognic compounds. For the toxicity test, P. subcaptitata was found to be a more sensitive organism to evaluate toxicity of antibiotics compared to D. magna and V. fischeri. The concentration of parent compounds and toxicity on algal growth were remarkably reduced by gamma radiation treatment. Also, remained concentration and some byproducts of target compounds after gamma irradiation method was additionally decreased by biodegradation and sorption of activated sludge. In addition, the effect of antibiotics on parental generation of D. magna is continued to the next generation. The sublethal concentration which showed no acute toxic effect have various abnormal effect such as reproduction and somatic growth, and it can reduce the population growth rate. Also, gamma irradiation was also effective method for reducing estrogen compounds remained in wastewater effluent

  10. Ecological risk assessment of antibiotics treated by radioactive rays

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Don; Lee, Byong Cheon; Kim, Hyun Young; Kim, Hyo Dong [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of)

    2011-05-15

    Removal efficiency of pharmaceuticals with various treatment methods and their toxicological tests were conducted to estimate the variations in toxicity using various organisms. The toxicity of target compounds on various aqueous organisms were conducted. Also, the removal efficiency of gamma-irradiated target compounds and their toxicity change was estimated. Furthermore, gamma-treatment was compared with degradation test with activated sludge and UV treatment due to decide the possibility of gamma-radiation as an alternative decomposing technique for the target compounds. Finally, the removal efficiency and estrogenicity of estrogenic compounds in gamma irradiated wastewater effluent was conducted. As a result, gamma radiation was an effective method for decomposing antibiotics and estrognic compounds. For the toxicity test, P. subcaptitata was found to be a more sensitive organism to evaluate toxicity of antibiotics compared to D. magna and V. fischeri. The concentration of parent compounds and toxicity on algal growth were remarkably reduced by gamma radiation treatment. Also, remained concentration and some byproducts of target compounds after gamma irradiation method was additionally decreased by biodegradation and sorption of activated sludge. In addition, the effect of antibiotics on parental generation of D. magna is continued to the next generation. The sublethal concentration which showed no acute toxic effect have various abnormal effect such as reproduction and somatic growth, and it can reduce the population growth rate. Also, gamma irradiation was also effective method for reducing estrogen compounds remained in wastewater effluent

  11. Antibiotic resistance in urban aquatic environments: can it be controlled?

    Science.gov (United States)

    Manaia, Célia M; Macedo, Gonçalo; Fatta-Kassinos, Despo; Nunes, Olga C

    2016-02-01

    Over the last decade, numerous evidences have contributed to establish a link between the natural and human-impacted environments and the growing public health threat that is the antimicrobial resistance. In the environment, in particular in areas subjected to strong anthropogenic pressures, water plays a major role on the transformation and transport of contaminants including antibiotic residues, antibiotic-resistant bacteria, and antibiotic resistance genes. Therefore, the urban water cycle, comprising water abstraction, disinfection, and distribution for human consumption, and the collection, treatment, and delivery of wastewater to the environment, is a particularly interesting loop to track the fate of antibiotic resistance in the environment and to assess the risks of its transmission back to humans. In this article, the relevance of different transepts of the urban water cycle on the potential enrichment and spread of antibiotic resistance is reviewed. According to this analysis, some gaps of knowledge, research needs, and control measures are suggested. The critical rationale behind the measures suggested and the desirable involvement of some key action players is also discussed. PMID:26649735

  12. Natural Polymers and their Application in Drug Delivery and Biomedical Field

    Directory of Open Access Journals (Sweden)

    Jana S*,1

    2011-01-01

    Full Text Available Biodegradable polymers are widely being studied as a potential carrier material for site specific drug delivery because of its non-toxic,biocompatible in nature. Natural polysaccharides have been investigated for drug delivery applications as well as in biomedical fields. Modified polymer has found its application as a support material for gene delivery, cell culture, and tissue engineering. Now a day, the polymer is being modified to obtain novel biomaterial for controlled drug delivery applications. This review provides an overview of the different modified polymer derivatives and their applications with special attention being put on controlled drug delivery and biomedical engineering.

  13. Biodegradable Metals From Concept to Applications

    CERN Document Server

    Hermawan, Hendra

    2012-01-01

    This book in the emerging research field of biomaterials covers biodegradable metals for biomedical applications. The book contains two main parts where each of them consists of three chapters. The first part introduces the readers to the field of metallic biomaterials, exposes the state of the art of biodegradable metals, and reveals its application for cardiovascular implants. It includes some fundamental aspects to give basic understanding on metals for further review on the degradable ones is covered in chapter one. The second chapter introduces the concept of biodegradable metals, it's st

  14. Biodegradation of surfactant bearing wastes

    International Nuclear Information System (INIS)

    In nuclear industry, during decontamination of protective wears and contaminated materials, detergents are employed to bring down the level of radioactive contamination within safe limits. However, the surfactant present in these wastes interferes in the chemical treatment process, reducing the decontamination factor. Biodegradation is an efficient and ecologically safe method for surfactant removal. A surfactant degrading culture was isolated and inoculated separately into simulated effluents containing 1% yeast extract and 5-100 ppm sodium lauryl sulphate (SLS) and 1% yeast extract and 5-100 ppm of commercial detergent respectively. The growth of the bacterial culture and the degradation characteristics of the surfactant in the above effluents were monitored under both dynamic and static conditions. (author). 6 refs., 6 figs., 1 tab

  15. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. PMID:21356588

  16. Engineered biosynthesis of biodegradable polymers.

    Science.gov (United States)

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers. PMID:27260524

  17. Integrated liquid chromatography method in enantioselective studies: Biodegradation of ofloxacin by an activated sludge consortium.

    Science.gov (United States)

    Maia, Alexandra S; Castro, Paula M L; Tiritan, Maria Elizabeth

    2016-09-01

    Ofloxacin is a chiral fluoroquinolone commercialized as racemate and as its enantiomerically pure form levofloxacin. This work presents an integrated liquid chromatography (LC) method with fluorescence detection (FD) and exact mass spectrometry (EMS) developed to assess the enantiomeric biodegradation of ofloxacin and levofloxacin in laboratory-scale microcosms. The optimized enantioseparation conditions were achieved using a macrocyclic antibiotic ristocetin A-bonded CSP (150×2.1mm i.d.; particle size 5μm) under reversed-phase elution mode. The method was validated using a mineral salts medium as matrix and presented selectivity and linearity over a concentration range from 5μgL(-1) (quantification limit) to 350μgL(-1) for each enantiomer. The method was successfully applied to evaluate biodegradation of ofloxacin enantiomers at 250μgL(-1) by an activated sludge inoculum. Ofloxacin (racemic mixture) and (S)-enantiomer (levofloxacin) were degraded up to 58 and 52%, respectively. An additional degradable carbon source, acetate, enhanced biodegradation up to 23%. (S)-enantiomer presented the highest extent of degradation (66.8%) when ofloxacin was supplied along with acetate. Results indicated slightly higher biodegradation extents for the (S)-enantiomer when supplementation was done with ofloxacin. Degradation occurred faster in the first 3days and proceeded slowly until the end of the assays. The chromatographic results from LC-FD suggested the formation of the (R)-enantiomer during levofloxacin biodegradation which was confirmed by LC-MS with a LTQ Orbitrap XL. PMID:27433982

  18. Biodegradation of halogenated organic compounds.

    Science.gov (United States)

    Chaudhry, G R; Chapalamadugu, S

    1991-03-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  19. [Antibiotic stability in magistral collyria].

    Science.gov (United States)

    Tihărău, A; Voiculescu, E; Vancea, S; Teodorescu, A; Cherecheş, S

    1990-01-01

    The paper presents the results of a study on physicochemical and and microbiological stability of collyria with such antibiotics as: Kanamicin, Oxacilin, Colistin, Erythromycin and Rifampicin. The authors insist on the necessity of preparing the ophthalmic solution with the antibiotics studies, with solvent for eye drops as provided for by RF IX and keeping at +4 degrees C, at dark. PMID:2101048

  20. Antibiotic Prophylaxis in Pediatric Dentistry

    OpenAIRE

    Davydova N.V.; Suyetenkov D.Ye.; Firsova I.V.; Oleynikova N.M.

    2011-01-01

    Identify options for the indications for antibiotic prophylaxis in children's dental reception. The analysis of publications shows that the basis of current trends prevention of postoperative wound infection in pediatric surgery should be measures aimed at eliminating or reducing the influence of risk factors, as well as the use of antibiotic prophylaxis

  1. Antibiotic Prophylaxis in Pediatric Dentistry

    Directory of Open Access Journals (Sweden)

    Davydova N.V.

    2011-03-01

    Full Text Available Identify options for the indications for antibiotic prophylaxis in children's dental reception. The analysis of publications shows that the basis of current trends prevention of postoperative wound infection in pediatric surgery should be measures aimed at eliminating or reducing the influence of risk factors, as well as the use of antibiotic prophylaxis

  2. The Antibiotic Resistance Problem Revisited

    Science.gov (United States)

    Lawson, Michael A.

    2008-01-01

    The term "antibiotic" was first proposed by Vuillemin in 1889 but was first used in the current sense by Walksman in 1941. An antibiotic is defined as a "derivative produced by the metabolism of microorganisms that possess antibacterial activity at low concentrations and is not toxic to the host." In this article, the author describes how…

  3. Preparation and degradation mechanisms of biodegradable polymer: a review

    Science.gov (United States)

    Zeng, S. H.; Duan, P. P.; Shen, M. X.; Xue, Y. J.; Wang, Z. Y.

    2016-07-01

    Polymers are difficult to degrade completely in Nature, and their catabolites may pollute the environment. In recent years, biodegradable polymers have become the hot topic in people's daily life with increasing interest, and a controllable polymer biodegradation is one of the most important directions for future polymer science. This article presents the main preparation methods for biodegradable polymers and discusses their degradation mechanisms, the biodegradable factors, recent researches and their applications. The future researches of biodegradable polymers are also put forward.

  4. The sorption of influenza viruses and antibiotics on carbon nanotubes and polyaniline nanocomposites

    International Nuclear Information System (INIS)

    The decontamination of the solutions from micropatogens and drug delivery are the important problems of modern life. It was shown that carbon nanotubes, polyaniline and their composites can interact with antibiotics-polypeptides and some viruses (pandemic strain of influenza viruses A(H1N1)v circulated in Russia in 2009-2010. During a short time drug and viruses can be absorbed by polyaniline and removed from aqueous solutions at the normal conditions. Polyaniline composites can be useful for the preparation of drug delivery and virus control filters and also in biotechnology for the improvement the methods of antibiotics purification.

  5. The sorption of influenza viruses and antibiotics on carbon nanotubes and polyaniline nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Ivanova, V T; Ilyna, M V; Kurochkina, Y E [D.I. Ivanovsky Research Institute of Virology RAMS, Gamaleya st, 16, Moscow 123098 (Russian Federation); Katrukha, G S [G.F.Gause Institute of New Antibiotics RAMS, Moscow 119021 (Russian Federation); Timofeeva, A V; Baratova, L A [A.N. Belozersky Research Institute for Physico-Chemical Biology, M.V.Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Sapurina, I Yu [Institute of Macromolecular Compounds RAS, 199004, St. Petersburgr. Bolshoy Pr.31 (Russian Federation); Ivanov, V F, E-mail: valivanova1946@mail.ru [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, RAS, Leninsky prospect, 31, Moscow 119991 (Russian Federation)

    2011-04-01

    The decontamination of the solutions from micropatogens and drug delivery are the important problems of modern life. It was shown that carbon nanotubes, polyaniline and their composites can interact with antibiotics-polypeptides and some viruses (pandemic strain of influenza viruses A(H1N1)v circulated in Russia in 2009-2010. During a short time drug and viruses can be absorbed by polyaniline and removed from aqueous solutions at the normal conditions. Polyaniline composites can be useful for the preparation of drug delivery and virus control filters and also in biotechnology for the improvement the methods of antibiotics purification.

  6. The Prehistory of Antibiotic Resistance.

    Science.gov (United States)

    Perry, Julie; Waglechner, Nicholas; Wright, Gerard

    2016-01-01

    Antibiotic resistance is a global problem that is reaching crisis levels. The global collection of resistance genes in clinical and environmental samples is the antibiotic "resistome," and is subject to the selective pressure of human activity. The origin of many modern resistance genes in pathogens is likely environmental bacteria, including antibiotic producing organisms that have existed for millennia. Recent work has uncovered resistance in ancient permafrost, isolated caves, and in human specimens preserved for hundreds of years. Together with bioinformatic analyses on modern-day sequences, these studies predict an ancient origin of resistance that long precedes the use of antibiotics in the clinic. Understanding the history of antibiotic resistance is important in predicting its future evolution. PMID:27252395

  7. Antibiotic tolerance and microbial biofilms

    DEFF Research Database (Denmark)

    Folkesson, Anders

    Increased tolerance to antimicrobial agents is thought to be an important feature of microbes growing in biofilms. We study the dynamics of antibiotic action within hydrodynamic flow chamber biofilms of Escherichia coli and Pseudomonas aeruginosa using isogenic mutants and fluorescent gene...... expression reporters and we address the question of how biofilm organization affects antibiotic susceptibility. The dynamics of microbial killing is monitored by viable count determination, and confocal laser microscopy. Our work shows that the apparent increased antibiotic tolerance is due to the formation...... of antibiotic tolerant subpopulations within the biofilm. The formation of these subpopulations is highly variable and dependent on the antibiotic used, the biofilm structural organization and the induction of specific tolerance mechanisms....

  8. Antibiotics for acute maxillary sinusitis

    DEFF Research Database (Denmark)

    Ahovuo-Saloranta, Anneli; Borisenko, Oleg V; Kovanen, Niina;

    2008-01-01

    antibiotics from different classes for acute maxillary sinusitis in adults. We included trials with clinically diagnosed acute sinusitis, whether or not confirmed by radiography or bacterial culture. DATA COLLECTION AND ANALYSIS: At least two review authors independently screened search results, extracted......BACKGROUND: Expert opinions vary on the appropriate role of antibiotics for sinusitis, one of the most commonly diagnosed conditions among adults in ambulatory care. OBJECTIVES: We examined whether antibiotics are effective in treating acute sinusitis, and if so, which antibiotic classes are the...... most effective. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, Issue 3); MEDLINE (1950 to May 2007) and EMBASE (1974 to June 2007). SELECTION CRITERIA: Randomized controlled trials (RCTs) comparing antibiotics with placebo or...

  9. Survey of Intraocular Antibiotics Prophylaxis Practice after Open Globe Injury in China.

    Directory of Open Access Journals (Sweden)

    Bingsheng Lou

    Full Text Available To elucidate the Chinese practice of intraocular antibiotics administration for prophylaxis after open globe injury.A cross-sectional questionnaire survey was performed online by scanning a Quickmark (QR code with smartphones at the 20th Chinese National Conference of Ocular Trauma in November 2014.A total of 153 (30.6% of all participators at the conference responded. Of the respondents, 20.9% were routinely administered with prophylactic intraocular injection of antibiotics at the conclusion of the primary eye repair, and 56.9% were used only in cases with high risk of endophthalmitis development. The intraocular route of delivery was mainly included with intracameral injection (47.9% and intravitreal injection (42.0%. Cephalosporins (53.8% and vancomycin (42.0% were the main choices of antibiotic agents, followed by fluoroquinolones (24.3%, and aminoglycosides (13.4%. Only 21.9% preferred a combination of two or more two drugs routinely. In addition, significantly more respondents from the referral eye hospital (92.7% replied using intraocular antibiotics injection for prophylaxis compared to those respondents from the primary hospital (69.4% (p = 0.001, Fisher's exact test.Intraocular antibiotics injection for post-traumatic endophthalmitis prophylaxis is widely used in China. However, the choice of antibiotic agents and the intraocular route of delivery vary. A well-designed clinical trial is needed to establish a standardized protocol of intraocular antibiotics administration for post-traumatic endophthalmitis prophylaxis.

  10. Survey of Intraocular Antibiotics Prophylaxis Practice after Open Globe Injury in China

    Science.gov (United States)

    Tan, Junlian; Yang, Yao; Yuan, Zhaohui; Lin, Xiaofeng

    2016-01-01

    Purpose To elucidate the Chinese practice of intraocular antibiotics administration for prophylaxis after open globe injury. Methods A cross-sectional questionnaire survey was performed online by scanning a Quickmark (QR) code with smartphones at the 20th Chinese National Conference of Ocular Trauma in November 2014. Results A total of 153 (30.6%) of all participators at the conference responded. Of the respondents, 20.9% were routinely administered with prophylactic intraocular injection of antibiotics at the conclusion of the primary eye repair, and 56.9% were used only in cases with high risk of endophthalmitis development. The intraocular route of delivery was mainly included with intracameral injection (47.9%) and intravitreal injection (42.0%). Cephalosporins (53.8%) and vancomycin (42.0%) were the main choices of antibiotic agents, followed by fluoroquinolones (24.3%), and aminoglycosides (13.4%). Only 21.9% preferred a combination of two or more two drugs routinely. In addition, significantly more respondents from the referral eye hospital (92.7%) replied using intraocular antibiotics injection for prophylaxis compared to those respondents from the primary hospital (69.4%) (p = 0.001, Fisher’s exact test). Conclusions Intraocular antibiotics injection for post-traumatic endophthalmitis prophylaxis is widely used in China. However, the choice of antibiotic agents and the intraocular route of delivery vary. A well-designed clinical trial is needed to establish a standardized protocol of intraocular antibiotics administration for post-traumatic endophthalmitis prophylaxis. PMID:27275777

  11. Antibiotic Resistance of Shigella Species in Iran

    OpenAIRE

    A.Mehr-Movahed; J. Nikkhah

    1987-01-01

    Antibiotic resistance in Shigella species has been showing a rising trend all over the world. This study was performed to discover the state of antibiotic resistance of Shigella species with regards to six common antibiotics in use in Iran.

  12. Biodegradable polymers: Which, when and why?

    Directory of Open Access Journals (Sweden)

    Kotwal V

    2007-01-01

    Full Text Available The plethora of drug therapies and types of drugs demand different formulations, fabrications conditions and release kinetics. No single polymer can satisfy all the requirements. Therefore there have been tremendous advances in area of biodegradable copolymers over the last 30 years. This article reviews current research on biodegradable polymers, focusing their potential as drug carries. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Other degradable polymers such as polyorthoesters, polyanhydrides and polyphosphazenes are also discussed and their advantages and disadvantages are summarized.

  13. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO2, NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  14. Photolysis of sulfamethoxypyridazine in various aqueous media: Aerobic biodegradation and identification of photoproducts by LC-UV–MS/MS

    International Nuclear Information System (INIS)

    Highlights: ► Sulfonamides are one of the most extensively used antibiotics in human and veterinary medicine. ► Sulfamethoxypyridazine (SMP) underwent photodegradation in three different media. ► SMP was not readily biodegradable. ► SMP and some of its degradation products were identified by LC-UV–MS/MS. -- Abstract: Sulfonamides are one of the most frequently used antibiotics worldwide. Therefore, mitigation processes such as abiotic or biotic degradation are of interest. Photodegradation and biodegradation are the potentially significant removal mechanisms for pharmaceuticals in aquatic environments. The photolysis of sulfamethoxypyridazine (SMP) using a medium pressure Hg-lamp was evaluated in three different media: Millipore water pH 6.1 (MW), effluent from sewage treatment plant pH 7.6 (STP), and buffered demineralized water pH 7.4 (BDW). Identification of transformation products (TPs) was performed by LC-UV–MS/MS. The biodegradation of SMP using two tests from the OECD series was studied: Closed Bottle test (OECD 301 D), and Manometric Respirometry test (OECD 301 F). In biodegradation tests, it was found that SMP was not readily biodegradable so it may pose a risk to the environment. The results showed that SMP was removed completely within 128 min of irradiation in the three media, and the degradation rate was different for each investigated type of water. However, dissolved organic carbon (DOC) was not removed in BDW and only little DOC removal was observed in MW and STP, thus indicating the formation of TPs. Analysis by LC-UV–MS/MS revealed new TPs formed. The hydroxylation of SMP represents the main photodegradation pathway

  15. Biodegradation of cresol isomers in anoxic aquifers.

    OpenAIRE

    Smolenski, W J; Suflita, J M

    1987-01-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers were preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradation of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol ...

  16. Biodegradation and toxicological evaluation of lubricant oils

    OpenAIRE

    Ivo Shodji Tamada; Paulo Renato Matos Lopes; Renato Nallin Montagnolli; Ederio Dino Bidoia

    2012-01-01

    The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei), arugula seeds (Eruca sativa) and lettuce seeds (Lactuca sativa), with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil) for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days...

  17. In vitro perforation of human epithelial carcinoma cell with antibody-conjugated biodegradable microspheres illuminated by a single 80 femtosecond near-infrared laser pulse

    Directory of Open Access Journals (Sweden)

    Terakawa M

    2012-05-01

    Full Text Available Mitsuhiro Terakawa, Yasuyuki Tsunoi, Tatsuki MitsuhashiDepartment of Electronics and Electrical Engineering, Keio University, Yokohama, Kanagawa, JapanAbstract: Pulsed laser interaction with small metallic and dielectric particles has been receiving attention as a method of drug delivery to many cells. However, most of the particles are attended by many risks, which are mainly dependent upon particle size. Unlike other widely used particles, biodegradable particles have advantages of being broken down and eliminated by innate metabolic processes. In this paper, the perforation of cell membrane by a focused spot with transparent biodegradable microspheres excited by a single 800 nm, 80 fs laser pulse is demonstrated. A polylactic acid (PLA sphere, a biodegradable polymer, was used. Fluorescein isothiocyanate (FITC-dextran and short interfering RNA were delivered into many human epithelial carcinoma cells (A431 cells by applying a single 80 fs laser pulse in the presence of antibody-conjugated PLA microspheres. The focused intensity was also simulated by the three-dimensional finite-difference time-domain method. Perforation by biodegradable spheres compared with other particles has the potential to be a much safer phototherapy and drug delivery method for patients. The present method can open a new avenue, which is considered an efficient adherent for the selective perforation of cells which express the specific antigen on the cell membrane.Keywords: femtosecond laser, drug delivery, transfection, biodegradable polymer

  18. Collagen macromolecular drug delivery systems

    International Nuclear Information System (INIS)

    The objective of this study was to examine collagen for use as a macromolecular drug delivery system by determining the mechanism of release through a matrix. Collagen membranes varying in porosity, crosslinking density, structure and crosslinker were fabricated. Collagen characterized by infrared spectroscopy and solution viscosity was determined to be pure and native. The collagen membranes were determined to possess native vs. non-native quaternary structure and porous vs. dense aggregate membranes by electron microscopy. Collagen monolithic devices containing a model macromolecule (inulin) were fabricated. In vitro release rates were found to be linear with respect to t1/2 and were affected by crosslinking density, crosslinker and structure. The biodegradation of the collagen matrix was also examined. In vivo biocompatibility, degradation and 14C-inulin release rates were evaluated subcutaneously in rats

  19. Biodegradability of Chlorinated Anilines in Waters

    Institute of Scientific and Technical Information of China (English)

    CHAO WANG; GUAN-GHUA LU; YAN-JIE ZHOU

    2007-01-01

    Objective To identify the bacteria tolerating chlorinated anilines and to study the biodegradability of o-chloroaniline and its coexistent compounds. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicant. Biodegradability of chlorinated anilines was determined using domesticated complex bacteria as an inoculum by shaking-flask test. Results The complex bacteria were identified, consisting of Xanthomonas, Bacillus alcaligenes,Acinetobacter, Pseudomonas, and Actinomycetaceae nocardia. The obtained complex bacteria were more tolerant to o-chloroaniline than mixture bacteria in natural river waters. The effects of exposure concentration and inoculum size on the biodegradability of o-chloroaniline were analyzed, and the biodegradation characteristics of single o-chloroaniline and 2,4-dichloroaniline were compared with the coexistent compounds. Conclusion The biodegradation rates can be improved by decreasing concentration of compounds and increasing inoculum size of complex bacteria. When o-chloroaniline coexists with aniline, the latter is biodegraded prior to the former, and as a consequence the metabolic efficiency of o-chloroaniline is improved with the increase of aniline concentration. Meanwhile, when o-chloroaniline coexists with 2,4-dichloroaniline, the metabolic efficiency of 2,4-dichloroaniline is markedly improved.

  20. Characterization of a Reverse-Phase Perfluorocarbon Emulsion for the Pulmonary Delivery of Tobramycin

    OpenAIRE

    Orizondo, Ryan A.; Babcock, Charlene Irvin; Fabiilli, Mario L.; Pavlovsky, Leonid; Fowlkes, J. Brian; Younger, John G.; Cook, Keith E.

    2014-01-01

    Background: Aerosolized delivery of antibiotics is hindered by poor penetration within distal and plugged airways. Antibacterial perfluorocarbon ventilation (APV) is a proposed solution in which the lungs are partially or totally filled with perfluorocarbon (PFC) containing emulsified antibiotics. The purpose of this study was to evaluate emulsion stability and rheological, antibacterial, and pharmacokinetic characteristics.

  1. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    Directory of Open Access Journals (Sweden)

    Roderick I. Mackie

    2013-07-01

    Full Text Available Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  2. Environmental and Public Health Implications of Water Reuse: Antibiotics, Antibiotic Resistant Bacteria, and Antibiotic Resistance Genes

    KAUST Repository

    Hong, Pei-Ying

    2013-07-31

    Water scarcity is a global problem, and is particularly acute in certain regions like Africa, the Middle East, as well as the western states of America. A breakdown on water usage revealed that 70% of freshwater supplies are used for agricultural irrigation. The use of reclaimed water as an alternative water source for agricultural irrigation would greatly alleviate the demand on freshwater sources. This paradigm shift is gaining momentum in several water scarce countries like Saudi Arabia. However, microbial problems associated with reclaimed water may hinder the use of reclaimed water for agricultural irrigation. Of particular concern is that the occurrence of antibiotic residues in the reclaimed water can select for antibiotic resistance genes among the microbial community. Antibiotic resistance genes can be associated with mobile genetic elements, which in turn allow a promiscuous transfer of resistance traits from one bacterium to another. Together with the pathogens that are present in the reclaimed water, antibiotic resistant bacteria can potentially exchange mobile genetic elements to create the “perfect microbial storm”. Given the significance of this issue, a deeper understanding of the occurrence of antibiotics in reclaimed water, and their potential influence on the selection of resistant microorganisms would be essential. In this review paper, we collated literature over the past two decades to determine the occurrence of antibiotics in municipal wastewater and livestock manure. We then discuss how these antibiotic resistant bacteria may impose a potential microbial risk to the environment and public health, and the knowledge gaps that would have to be addressed in future studies. Overall, the collation of the literature in wastewater treatment and agriculture serves to frame and identify potential concerns with respect to antibiotics, antibiotic resistant bacteria, and antibiotic resistance genes in reclaimed water.

  3. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amides

    Directory of Open Access Journals (Sweden)

    Angélica Díaz

    2014-04-01

    Full Text Available Poly(alkylene dicarboxylates constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amides derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  4. Systemic antibiotic therapy in periodontics

    Directory of Open Access Journals (Sweden)

    Anoop Kapoor

    2012-01-01

    Full Text Available Systemic antibiotics in conjunction with scaling and root planing (SRP, can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of clinical attachment loss (CAL and pocket depth change, and reduced risk of additional CAL loss. However, antibiotics are not innocuous drugs. Their use should be justified on the basis of a clearly established need and should not be substituted for adequate local treatment. The aim of this review is to discuss the rationale, proper selection, dosage and duration for antibiotic therapy so as to optimize the usefulness of drug therapy.

  5. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    Directory of Open Access Journals (Sweden)

    Geoffrey Ivan Scott

    2016-04-01

    Full Text Available ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs. CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CECs that pose significant environmental risks including development of both toxic effects at high doses and antibiotic resistance at doses well below the Minimum Inhibitory Concentration (MIC which kill bacteria and have been found in nearly half of all sites monitored in the US. Antimicrobial resistance has generally been attributed to the use of antibiotics in medicine for humans and livestock as well as aquaculture operations. The objective of this study was to assess the extent and magnitude of antibiotics in the environment and estimate their potential hazards in the environment. Antibiotics concentrations were measured in a number of monitoring studies which included Waste Water Treatment Plants (WWTP effluent, surface waters, sediments and biota. A number of studies reported levels of Antibiotic Resistant Microbes (ARM in surface waters and some studies found specific ARM genes (e.g. the blaM-1 gene in E. coli which may pose additional environmental risk. High levels of this gene were found to survive WWTP disinfection and accumulated in sediment at levels 100-1000 times higher than in the sewerage effluent, posing potential risks for gene transfer to other bacteria.in aquatic and marine ecosystems. Antibiotic risk assessment approaches were developed based on the use of MICs and MIC Ratios [High (Antibiotic Resistant/Low (Antibiotic Sensitive MIC] for each antibiotic indicating the range of bacterial adaptability to each antibiotic to help define the No

  6. The use of inert carriers in regulatory biodegradation tests of low density poorly water-soluble substances.

    Science.gov (United States)

    Handley, J W; Mead, C; Rausina, G A; Waid, L J; Gee, J C; Herron, S J

    2002-08-01

    Many poorly water-soluble compounds fail regulatory ready biodegradation tests as the method of test material preparation limits the bioavailability of the chemical. The recognised method for delivery of poorly soluble materials into biodegradability tests consists of coating test material inside the test vessel or onto inert substrates (i.e., glass cover slide, boiling beads, filter paper, or Teflon stir bar) that are placed inside the vessels. Volatile solvents are often used to augment this process. Although these substrates work fairly well for delivering many poorly soluble materials into biodegradability tests, they have not been effective in keeping low density, poorly water-soluble substances in the test medium. Soon after medium is added to the test vessels, these chemicals break loose from the substrates and float on the surface where they have limited contact with micro-organisms in the test medium. Hence, there is a reduced potential for measuring substantial biodegradability in the test. This paper describes the work undertaken to establish a standard method of adding low density, poorly water-soluble substances into test vessels of biodegradability studies to ensure these materials remain in contact with micro-organisms in the test medium. The substances are prepared for testing by adsorption onto silica gel followed by dispersion into the culture medium. This method of delivery may provide greater intra- and inter-laboratory consistency in biodegradability test results for low density, poorly water-soluble substances and it may more closely mimic the probable transport and fate of these substances in the environment. PMID:12146631

  7. Prophylactic antibiotics versus post- operative antibiotics in herniorraphy

    Directory of Open Access Journals (Sweden)

    Abedulla Khan Kayamkani

    2015-07-01

    Full Text Available Postoperative surgical site infections are a major source of illness.  Infection results in longer hospital stay and higher costs.  Uses of preoperative antibiotics have been standardized and are being used routinely in most clinical surgeries and include controversial areas like breast surgery and herniorraphy. Objective of the study is to find out the benefit of prophylactic use of antibiotics in the management of herniorraphy.This project was carried out in a multispeciality tertiary care teaching hospital from 1st-30th April in 2002. Group 1 patients were treated prophylactically half an hour before surgery with single dose of I.V. antibiotics (injection.  Ampicillin 1gm + injection.  Gentamicin 80mg. Group 2 patients were treated post surgery with capsule. Ampicillin 500mg 4 times a day for 7 days and injection. Gentamicin twice a day for first 4 days. In case of group 1 patients only one out of 20 patients (5% was infected.  Whereas in-group 2 patients 5 out of 20 patients (25% were infected. The cost of prophylactic antibiotic treatment was Rs. 25.56 per patient.  The postoperative antibiotic treatment cost was Rs. 220.4 per patient.  That means postoperative treatment is around 8.62 times costlier than prophylactic treatment.             From this study it is evident that prophylactic (preoperative treatment is better than postoperative treatment with antibiotics.

  8. Sustained Release of Antibacterial Lipopeptides from Biodegradable Polymers against Oral Pathogens.

    Science.gov (United States)

    Eckhard, Lea H; Houri-Haddad, Yael; Sol, Asaf; Zeharia, Rotem; Shai, Yechiel; Beyth, Shaul; Domb, Abraham J; Bachrach, Gilad; Beyth, Nurit

    2016-01-01

    The development of antibacterial drugs to overcome various pathogenic species, which inhabit the oral cavity, faces several challenges, such as salivary flow and enzymatic activity that restrict dosage retention. Owing to their amphipathic nature, antimicrobial peptides (AMPs) serve as the first line of defense of the innate immune system. The ability to synthesize different types of AMPs enables exploitation of their advantages as alternatives to antibiotics. Sustained release of AMPs incorporated in biodegradable polymers can be advantageous in maintaining high levels of the peptides. In this study, four potent ultra-short lipopeptides, conjugated to an aliphatic acid chain (16C) were incorporated in two different biodegradable polymers: poly (lactic acid co castor oil) (PLACO) and ricinoleic acid-based poly (ester-anhydride) (P(SA-RA)) for sustained release. The lipopeptide and polymer formulations were tested for antibacterial activity during one week, by turbidometric measurements of bacterial outgrowth, anti-biofilm activity by live/dead staining, biocompatibility by hemolysis and XTT colorimetric assays, mode of action by fluorescence-activated cell sorting (FACS) and release profile by a fluorometric assay. The results show that an antibacterial and anti-biofilm effect, as well as membrane disruption, can be achieved by the use of a formulation of lipopeptide incorporated in biodegradable polymer. PMID:27606830

  9. Mission Critical: Preventing Antibiotic Resistance

    Science.gov (United States)

    ... Remember antibiotics have side effects. Prevent infections by practicing good hand hygiene and getting recommended vaccines. View ... program that includes, at a minimum, this checklist : Leadership commitment: Dedicate necessary human, financial, and IT resources. ...

  10. Antibiotic resistance of bacterial biofilms

    DEFF Research Database (Denmark)

    Hoiby, N.; Bjarnsholt, T.; Givskov, M.;

    2010-01-01

    A biofilm is a structured consortium of bacteria embedded in a self-produced polymer matrix consisting of polysaccharide, protein and DNA. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and disinfectant chemicals as well as resisting phagocytosis...... to antibiotics. Biofilm growth is associated with an increased level of mutations as well as with quorum-sensing-regulated mechanisms. Conventional resistance mechanisms such as chromosomal beta-lactamase, upregulated efflux pumps and mutations in antibiotic target molecules in bacteria also contribute...... to the survival of biofilms. Biofilms can be prevented by early aggressive antibiotic prophylaxis or therapy and they can be treated by chronic suppressive therapy. A promising strategy may be the use of enzymes that can dissolve the biofilm matrix (e.g. DNase and alginate lyase) as well as quorum...

  11. In situ thermally enhanced biodegradation of petroleum fuel hydrocarbons and halogenated organic solvents

    International Nuclear Information System (INIS)

    An in situ thermally enhanced microbial remediation strategy and a method for the biodegradation of toxic petroleum fuel hydrocarbon and halogenated organic solvent contaminants are described. The method utilizes nonpathogenic, thermophilic bacteria for the thermal biodegradation of toxic and carcinogenic contaminants, such as benzene, toluene, ethylbenzene and xylenes, from fuel leaks and the chlorinated ethenes, such as trichloroethylene, chlorinated ethanes, such as 1,1,1-trichloroethane, and chlorinated methanes, such as chloroform, from past solvent cleaning practices. The method relies on and takes advantage of the pre-existing heated conditions and the array of delivery/recovery wells that are created and in place following primary subsurface contaminant volatilization efforts via thermal approaches, such as dynamic underground steam-electrical heating. 21 figs

  12. Susceptibility of antibiotic-resistant and antibiotic-sensitive foodborne pathogens to acid anionic sanitizers.

    Science.gov (United States)

    Lopes, J A

    1998-10-01

    Acid anionic sanitizers for treatment of fruits and vegetables were prepared using ingredients generally recognized as safe by the U.S. Food and Drug Administration or anionic surfactants and organic acid food additives. They met the regulatory definition as sanitizers by showing bactericidal efficacy of 99.999% in 30 s against Staphylococcus aureus ATCC 6538 and Escherichia coli ATCC 11229. These sanitizers showed a broad spectrum of microbicidal activity against both gram-positive and gram-negative bacteria. Antibiotic-sensitive and resistant strains of Listeria monocytogenes and Salmonella typhimurium were equally susceptible to these sanitizers. The acid anionic sanitizers showed microbicidal efficacy equal to that of hypochlorite against Aeromonas hydrophila, E. coli O157:H7, L. monocytogenes, Pseudomonas aeruginosa, S. typhimurium, and S. aureus. Unlike most other sanitizers, these agents do not covalently react with organic components of food; unlike cationic agents, they do not leave residues. The acid anionic sanitizers are prepared using stable, biodegradable, and nontoxic ingredients. Rapid microbicidal activity and the ease of storage, transportation, and use make these sanitizers an attractive alternative to hypochlorite for sanitizing fruits and vegetables. PMID:9798163

  13. Antibiotic associated diarrhoea: Infectious causes

    OpenAIRE

    Ayyagari A; Agarwal J; Garg A

    2003-01-01

    Nearly 25% of antibiotic associated diarrhoeas (AAD) is caused by Clostridium difficile, making it the commonest identified and treatable pathogen. Other pathogens implicated infrequently include Clostridium perfringens, Staphylococcus aureus, Klebsiella oxytoca, Candida spp. and Salmonella spp. Most mild cases of AAD are due to non-infectious causes which include reduced break down of primary bile acids and decrease metabolism of carbohydrates, allergic or toxic effects of antibiotic ...

  14. Systemic antibiotic therapy in periodontics

    OpenAIRE

    Anoop Kapoor; Ranjan Malhotra; Vishakha Grover; Deepak Grover

    2012-01-01

    Systemic antibiotics in conjunction with scaling and root planing (SRP), can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of clinical attachment loss (CAL) and pocket depth change, and reduced risk of additional CAL loss. However, antibiotics are not innocuous drugs. Their use should be justified on the basis of a clearly established need and should not be substituted for adequate local treatment. The aim of this review is to discuss the rationale, pr...

  15. Antibiotic resistance in wild birds

    OpenAIRE

    Bonnedahl, Jonas; Järhult, Josef D.

    2014-01-01

    Wild birds have been postulated as sentinels, reservoirs, and potential spreaders of antibiotic resistance. Antibiotic-resistant bacteria have been isolated from a multitude of wild bird species. Several studies strongly indicate transmission of resistant bacteria from human rest products to wild birds. There is evidence suggesting that wild birds can spread resistant bacteria through migration and that resistant bacteria can be transmitted from birds to humans and vice versa. Through further...

  16. [Self-medication with antibiotics in Poland

    NARCIS (Netherlands)

    Olczak, A.; Grzesiowski, P.; Hryniewicz, W.; Haaijer-Ruskamp, F.M.

    2006-01-01

    Antibiotic resistance, the important public health threat, depends on antibiotic overuse/misuse. Self-medication with antibiotics is of serious medical concern. The aim of the study, as a part of SAR project (Self-medication with antibiotic in Europe) was to survey the incidence of this phenomenon.

  17. Expedient antibiotics production: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bienkowski, P.R.; Byers, C.H.; Lee, D.D.

    1988-05-01

    The literature on the manufacture, separation and purification, and clinical uses of antibiotics was reviewed, and a bibliography of the pertinent material was completed. Five antimicrobial drugs, penicillin V and G, (and amoxicillin with clavulanic acid), Cephalexin (a cephalosporin), tetracycline and oxytetracycline, Bacitracin (topical), and sulfonamide (chemically produced) were identified for emergency production. Plants that manufacture antibiotics in the continental United States, Mexico, and Puerto Rico have been identified along with potential alternate sites such as those where SCP, enzyme, and fermentation ethanol are produced. Detailed process flow sheets and process descriptions have been derived from the literature and documented. This investigation revealed that a typical antibiotic-manufacturing facility is composed of two main sections: (1) a highly specialized, but generic, fermentation unit and (2) a multistep, complex separation and purification unit which is specific to a particular antibiotic product. The fermentation section requires specialized equipment for operation in a sterile environment which is not usually available in other industries. The emergency production of antibiotics under austere conditions will be feasible only if a substantial reduction in the complexity and degree of separation and purity normally required can be realized. Detailed instructions were developed to assist state and federal officials who would be directing the resumption of antibiotic production after a nuclear attack. 182 refs., 54 figs., 26 tabs.

  18. Ketoprofen-eluting biodegradable ureteral stents by CO2 impregnation: In vitro study.

    Science.gov (United States)

    Barros, Alexandre A; Oliveira, Carlos; Reis, Rui L; Lima, Estevão; Duarte, Ana Rita C

    2015-11-30

    Ureteral stents are indispensable tools in urologic practice. The main complications associated with ureteral stents are dislocation, infection, pain and encrustation. Biodegradable ureteral stents are one of the most attractive designs with the potential to eliminate several complications associated with the stenting procedure. In this work we hypothesize the impregnation of ketoprofen, by CO2-impregnation in a patented biodegradable ureteral stent previously developed in our group. The biodegradable ureteral stents with each formulation: alginate-based, gellan gum-based were impregnated with ketoprofen and the impregnation conditions tested were 100 bar, 2 h and three different temperatures (35 °C, 40 °C and 50 °C). The impregnation was confirmed by FTIR and DSC demonstrated the amorphization of the drug upon impregnation. The in vitro elution profile in artificial urine solution (AUS) during degradation of a biodegradable ureteral stent loaded with ketoprofen was evaluated. According to the kinetics results these systems have shown to be very promising for the release ketoprofen in the first 72 h, which is the necessary time for anti-inflammatory delivery after the surgical procedure. The in vitro release studied revealed an influence of the temperature on the impregnation yield, with a higher impregnation yield at 40 °C. Higher yields were also obtained for gellan gum-based stents. The non-cytotoxicity characteristic of the developed ketoprofen-eluting biodegradable ureteral stents was evaluated in L929 cell line by MTS assay which demonstrated the feasibility of this product as a medical device. PMID:26392243

  19. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  20. Bio-Degradable Plastics Impact On Environment

    Directory of Open Access Journals (Sweden)

    T.SUBRAMANI

    2014-06-01

    Full Text Available The potential of biodegradable polymers and more particularly that of polymers obtained from renewable resources such as the polysaccharides (e.g., starch have long been recognized. However, these biodegradable polymers have been largely used in some applications (e.g., food industry and have not found extensive applications in the packaging industries to replace conventional plastic materials, although they could be an interesting way to overcome the limitation of the petrochemical resources in the future. The fossil fuel and gas could be partially replaced by greener agricultural sources, which should participate in the reduction of CO2 emissions. Bio-based and biodegradable plastics can form the basis for environmentally preferable, sustainable alternative to current materials based exclusively on petroleum feed stocks. These bio-based materials offer value in the sustainability/life-cycle equation by being a part of the biological carbon cycle, especially as it relates to carbon-based polymeric materials such as plastics, water soluble polymers and other carbon based products like lubricants, biodiesel, and detergents. Identification and quantification of bio based content uses radioactive C-14 signature. Biopolymers are generally capable of being utilized by living matter (biodegraded, and so can be disposed in safe and ecologically sound ways through disposal processes (waste management like composting, soil application, and biological wastewater treatment. Single use, short-life, disposable products can be engineered to be bio-based and biodegradable.

  1. Macrolide antibiotics and the airway: antibiotic or non-antibiotic effects?

    LENUS (Irish Health Repository)

    Murphy, D M

    2010-03-01

    The macrolides are a class of antibiotics widely prescribed in infectious disease. More recently, there has been considerable interest in potential indications for these agents, in addition to their simple antibacterial indications, in a number of lung pathophysiologies.

  2. Use of functional gene arrays for elucidating in situ biodegradation

    Directory of Open Access Journals (Sweden)

    JoyD.Van Nostrand

    2012-09-01

    Full Text Available Microarrays have revolutionized the study of microbiology by providing a high-throughput method for examining thousands of genes with a single test and overcome the limitations of many culture-independent approaches. Functional gene arrays (FGA probe a wide range of genes involved in a variety of functions of interest to microbial ecology (e.g., carbon degradation, N-fixation, metal resistance from many different microorganisms, cultured and uncultured. The most comprehensive FGA to date is the GeoChip array, which targets tens of thousands of genes involved in the geochemical cycling of carbon, nitrogen, phosphorus, and sulphur, metal resistance and reduction, energy processing, antibiotic resistance and contaminant degradation as well as phylogenetic information (gyrB. Since the development of GeoChips, many studies have been performed using this FGA and have shown it to be a powerful tool for rapid, sensitive and specific examination of microbial communities in a high-throughput manner. As such, the GeoChip is well-suited for linking geochemical processes with microbial community function and structure. This technology has been used successfully to examine microbial communities before, during and after in situ bioremediation at a variety of contaminated sites. These studies have expanded our understanding of biodegradation and bioremediation processes and the associated microorganisms and environmental conditions responsible. This review provides an overview of FGA development with a focus on the GeoChip and highlights specific GeoChip studies involving in situ bioremediation.

  3. Antibiotic use in Lithuania, 2003 - 2008

    OpenAIRE

    Beržanskytė, Aušra

    2009-01-01

    Antimicrobial resistance is mainly caused by inappropriate and abundant use of antibiotics. To enlighten the most relevant problematic areas in antibiotic use, where the decisions should be made, the different levels were analysed in this study: the self-medication with antibiotics of the population, ambulatory and also hospital antibiotic use. The results showed that wrong perception about antibiotics is characteristic to Lithuanian population, as there is lack of privity, while traditions o...

  4. Antibiotics: Use and misuse in pediatric dentistry

    Directory of Open Access Journals (Sweden)

    F C Peedikayil

    2011-01-01

    Full Text Available Antibiotics are commonly used in dentistry for prophylactic as well as for therapeutic purposes. Most often antibiotics are used in unwarranted situations, which may give rise to resistant bacterial strains. Dentists want to make their patients well and to prevent unpleasant complications. These desires, coupled with the belief that many oral problems are infectious, stimulate the prescribing of antibiotics. Good knowledge about the indications of antibiotics is the need of the hour in prescribing antibiotics for dental conditions.

  5. Investigation of Degradation Properties of Poly(lactide-co-glycolide) Matrix for Anticancer Agent Delivery

    International Nuclear Information System (INIS)

    Poly(lactide-co-glycolide)(PLA50GA50) is a biodegradable and biocompatible polymer. It offers tremendous potential as a basis for drug delivery, either as drug delivery system alone or in conjugate with a medical device. The PLA50GA50 is the material of choice for relatively shorter-duration applications, while the homopolymer PLA (poly-L-lactide) and PGA (polyglycolide) are preferred for longer term delivery of drugs. This paper discusses the degradation properties of poly(lactide-co-glycolide)(PLA50GA50) at inherent viscosity of 0.89 dL/g as preliminary studies for anticancer agent delivery.

  6. Biodegradable mucus-penetrating nanoparticles composed of diblock copolymers of polyethylene glycol and poly(lactic-co-glycolic acid)

    OpenAIRE

    Yu, Tao; Wang, Ying-Ying; Yang, Ming; Schneider, Craig; Zhong, Weixi; Pulicare, Sarah; Choi, Woo-Jin; Mert, Olcay; Fu, Jie; Lai, Samuel K.; Hanes, Justin

    2012-01-01

    Mucus secretions coating entry points to the human body that are not covered by skin efficiently trap and clear conventional drug carriers, limiting controlled drug delivery at mucosal surfaces. To overcome this challenge, we recently engineered nanoparticles that readily penetrate a variety of human mucus secretions, which we termed mucus-penetrating particles (MPP). Here, we report a new biodegradable MPP formulation based on diblock copolymers of poly(lactic-co-glycolic acid) and poly(ethy...

  7. Premature delivery

    Directory of Open Access Journals (Sweden)

    Bernardita Donoso Bernales

    2012-09-01

    Full Text Available Preterm delivery is the single most important cause of perinatal morbidity and mortality. In Chile, preterm births have increased in the past decade, although neonatal morbidity and mortality attributable to it shows a downward trend, thanks to improvements in neonatal care of premature babies, rather than the success of obstetric preventive and therapeutic strategies. This article describes clinical entities, disease processes and conditions that constitute predisposing factors of preterm birth, as well as an outline for the prevention and clinical management of women at risk of preterm birth.

  8. Controlling silk fibroin particle features for drug delivery

    OpenAIRE

    Lammel, Andreas; Hu, Xiao; Park, Sang-Hyug; Kaplan, David L.; Scheibel, Thomas

    2010-01-01

    Silk proteins are a promising material for drug delivery due to their aqueous processability, biocompatibility, and biodegradability. A simple aqueous preparation method for silk fibroin particles with controllable size, secondary structure and zeta potential is reported. The particles were produced by salting out a silk fibroin solution with potassium phosphate. The effect of ionic strength and pH of potassium phosphate solution on the yield and morphology of the particles was determined. Se...

  9. Rational design of purely peptidic amphiphiles for drug delivery applications

    OpenAIRE

    Bruyn Ouboter, Dirk de

    2011-01-01

    A broad range of new properties is emerging from supramolecular aggregates. Self-assembled structures of purely peptidic amphiphiles exploit these properties to produce biocompatible, biodegradable, smart materials for drug administration. This thesis explores the design, synthesis, purification, characterization of purely peptidic amphiphiles, and evaluates potential applications. The first chapter provides a general introduction to the field of self-assembly, and of drug delivery as com...

  10. Biodegradable Photonic Melanoidin for Theranostic Applications.

    Science.gov (United States)

    Lee, Min-Young; Lee, Changho; Jung, Ho Sang; Jeon, Mansik; Kim, Ki Su; Yun, Seok Hyun; Kim, Chulhong; Hahn, Sei Kwang

    2016-01-26

    Light-absorbing nanoparticles for localized heat generation in tissues have various biomedical applications in diagnostic imaging, surgery, and therapies. Although numerous plasmonic and carbon-based nanoparticles with strong optical absorption have been developed, their clearance, potential cytotoxicity, and long-term safety issues remain unresolved. Here, we show that "generally regarded as safe (GRAS)" melanoidins prepared from glucose and amino acid offer a high light-to-heat conversion efficiency, biocompatibility, biodegradability, nonmutagenicity, and efficient renal clearance, as well as a low cost for synthesis. We exhibit a wide range of biomedical photonic applications of melanoidins, including in vivo photoacoustic mapping of sentinel lymph nodes, photoacoustic tracking of gastrointestinal tracts, photothermal cancer therapy, and photothermal lipolysis. The biodegradation rate and renal clearance of melanoidins are controllable by design. Our results confirm the feasibility of biodegradable melanoidins for various photonic applications to theranostic nanomedicines. PMID:26623481

  11. Biodegradable Polymers and Stem Cells for Bioprinting

    Directory of Open Access Journals (Sweden)

    Meijuan Lei

    2016-04-01

    Full Text Available It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  12. Biodegradable Polymers and Stem Cells for Bioprinting.

    Science.gov (United States)

    Lei, Meijuan; Wang, Xiaohong

    2016-01-01

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism. PMID:27136526

  13. Petroleum biodegradation and oil spill bioremediation

    International Nuclear Information System (INIS)

    Hydrocarbon-utilizing microorganisms are ubiquitously distributed in the marine environment following oil spills. These microorganisms naturally biodegrade numerous contaminating petroleum hydrocarbons, thereby cleansing the oceans of oil pullutants. Bioremediation, which is accomplished by adding exogenous microbial populations or stimulating indigenous ones, attempts to raise the rates of degradation found naturally to significantly higher rates. Seeding with oil degraders has not been demonstrated to be effective, but addition of nitrogenous fertilizers has been shown to increase rates of petroleum biodegradation. In the case of the Exxon Valdez spill, the largest and most thoroughly studied application of bioremediation, the application of fertilizer (slow release or oleophilic) increased rates of biodegradation 3-5 times. Because of the patchiness of oil, an internally conserved compound, hopane, was critical for demonstrating the efficacy of bioremediation. Multiple regression models showed that the effectiveness of bioremediation depended upon the amount of nitrogen delivered, the concentration of oil, and time. (author)

  14. Risk of Asthma from Cesarean Delivery Depends on Membrane Rupture

    DEFF Research Database (Denmark)

    Sevelsted, Astrid; Stokholm, Jakob; Bisgaard, Hans

    2016-01-01

    weight, gestational age, multiple births, parity, and maternal factors (age, smoking/antibiotics during pregnancy,employment status, and asthma). RESULTS: In the Copenhagen Prospective Studies on Asthma in Childhood2000 cohort, the adjusted hazard ratio for asthma was increased by cesarean delivery...... rate ratio to vaginal delivery 1.12 [1.09-1.16]). CONCLUSIONS: We confirmed cesarean delivery to be a risk factor for childhood asthma. This effect was more pronounced for cesarean delivery performed before rupture of membranes.......OBJECTIVE: To assess our prospective mother-child cohort and the national registry data to analyze the risk of asthma by delivery mode and whether cesarean delivery before or after membrane rupture affects this risk differently. STUDY DESIGN: The Copenhagen Prospective Studies on Asthma in...

  15. Biodegradability Evaluation of Polymers by ISO 14855-2

    OpenAIRE

    Masao Kunioka; Fumi Ninomiya; Masahiro Funabashi

    2009-01-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradabi...

  16. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  17. Histological evaluation of different biodegradable and non-biodegradable membranes implanted subcutaneously in rats

    DEFF Research Database (Denmark)

    Zhao, S; Pinholt, E M; Madsen, J E; Donath, K

    2000-01-01

    Different types of biodegradable membranes have become available for guided tissue regeneration. The purpose of this study was to evaluate histologically three different biodegradable membranes (Bio-Gide, Resolut and Vicryl) and one non-biodegradable membrane (expanded polytetrafluoroethylene/e-PTFE...... that e-PTFE was well tolerated and encapsulated by a fibrous connective tissue capsule. There was capsule formation around Resolut and Vicryl and around Bio-Gide in the early phase there was a wide inflammatory zone already. e-PTFE and Vicryl were stable materials while Resolut and Bio-Gide fragmented...

  18. Management Options For Reducing The Release Of Antibiotics And Antibiotic Resistance Genes To The Environment

    Science.gov (United States)

    Background: There is growing concern worldwide about the role of polluted soil and water - 77 environments in the development and dissemination of antibiotic resistance. 78 Objective: To identify management options for reducing the spread of antibiotics and 79 antibiotic resist...

  19. Background antibiotic resistance patterns in antibiotic-free pastured poultry production

    Science.gov (United States)

    Antibiotic resistance (AR) is a significant public health issue, and agroecosystems are often viewed as major environmental sources of antibiotic resistant foodborne pathogens. While the use of antibiotics in agroecosystems can potentially increase AR, appropriate background resistance levels in th...

  20. Biodegradable containers from green waste materials

    Science.gov (United States)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  1. Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

    International Nuclear Information System (INIS)

    The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

  2. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; Ma, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  3. Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

    Institute of Scientific and Technical Information of China (English)

    YI Feng; YU Jian; LI Qiang; GUO Zhaoxia

    2007-01-01

    The antibacterial property and biodegradability of soluble eggshell membrane protein (SEP)are reported. Unlike the natural eggshell membrane (ESM), SEP does not possess antibacterial property against E.coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.

  4. Antibiotic allergy in cystic fibrosis.

    Science.gov (United States)

    Parmar, J S; Nasser, S

    2005-06-01

    Allergic reactions to antibiotics are more common in cystic fibrosis (CF) than in the general population. This in part is due to the improving survival in adults with CF and the increased use of high dose intravenous antibiotics. While some are immediate anaphylaxis type (IgE mediated) reactions, the majority are late onset and may have non-specific features such as rash and fever. Piperacillin has consistently been found to have the highest rate of reported reactions (30-50%). There is a low risk of cross reactions between penicillins and other non-beta-lactam classes of antibiotics in penicillin skin prick positive patients. Carbapenems should only be used with extreme caution in patients with positive skin prick tests to penicillin. However, aztreonam can be used safely in patients who are penicillin allergic with positive skin prick reactions. The aminoglycosides are a relatively uncommon cause of allergic reactions, but patients who react to one member of the family may cross react with other aminoglycosides. Desensitisation relies on the incremental introduction of small quantities of the allergen and has been used for penicillins, ceftazidime, tobramycin and ciprofloxacin and must be repeated before each course. Personalized cards should be regularly updated for patients who develop allergic reactions. Written instructions on the emergency treatment of allergic reactions should be provided to patients self-administering intravenous antibiotics at home. Further research is required to identify risk factors and predictors for antibiotic allergy. PMID:15923254

  5. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    Directory of Open Access Journals (Sweden)

    Giuseppe Cirillo

    2014-01-01

    Full Text Available The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior. The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review.

  6. [Method for Simultaneous Determination of 11 Veterinary Antibiotics in Piggery Wastewater and Sludge and Its Application in Biological Treatment].

    Science.gov (United States)

    Ding, Jia-li; Liu, Rui; Zheng, Wei; Yu, Wei-juan; Ye, Zhao-xia; Chen, Lu-jun; Zhang, Yong-ming

    2015-10-01

    In order to determine eleven commonly used veterinary antibiotics (including four tetracyclines, two sulfonamides, three quinolones and two macrolides) in piggery wastewater and activated sludge in the Yangtze River Delta region, the conditions of solid phase extraction and high performance liquid chromatography-tandem mass spectrometry were optimized. The recovery rate and relative standard deviations of the method were confirmed as 73% - 105.2%, 3.1% - 10.2% for piggery wastewater (n = 3) and 57.4% - 104.6%, 1.9% - 10.9% (n = 3) respectively for the activated sludge. Removal of antibiotics was then studied in a membrane bioreactor. The results showed that antibiotics of both tetracycline and sulfonamide species took a large portion in the wastewater, while tetracycline species were the dominant in the sludge. Tetracycline species in the wastewater were removed by 85.2%, mainly through biodegradation (51.9%) and secondly by sludge adsorption (33.2%). By comparison, sulfonamide species was removed by 95.8%, almost all through biodegradation while little by sludge adsorption. Flask tests suggested that the accumulated antibiotics in the sludge give no significant influence on the microbial removal of organics and ammonium. PMID:26841632

  7. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    Science.gov (United States)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  8. Novel Pentablock Copolymer-Based Nanoparticulate Systems for Sustained Protein Delivery

    OpenAIRE

    Patel, Sulabh P.; Vaishya, Ravi; Pal, Dhananjay; Mitra, Ashim K.

    2014-01-01

    The design, synthesis, and application of novel biodegradable and biocompatible pentablock (PB) copolymers, i.e., polyglycolic acid-polycaprolactone-polyethylene glycol-polycaprolactone-polyglycolic acid (PGA-PCL-PEG-PCL-PGA) and polylactic acid-polycaprolactone-polyethylene glycol-polycaprolactone-polylactic acid (PLA-PCL-PEG-PCL-PLA) for sustained protein delivery, are reported. The PB copolymers can be engineered to generate sustained delivery of protein therapeutics to the posterior segme...

  9. Poly(trimethylene carbonate)-based polymers engineered for biodegradable functional biomaterials.

    Science.gov (United States)

    Fukushima, K

    2016-01-01

    Aliphatic polycarbonates have drawn attention as biodegradable polymers that can be applied to a broad range of resorbable medical devices. In particular, poly(trimethylene carbonate) (PTMC), its copolymers, and its derivatives are currently studied due to their unique degradation characteristics that are different from those of aliphatic polyesters. Furthermore, their flexible and hydrophobic nature has driven the application of PTMC-based polymers to soft tissue regeneration and drug delivery. This review presents the diverse applications and functionalization strategies of PTMC-based materials in relation to recent advances in medical technologies and their subsequent needs in clinical settings. PMID:26323327

  10. The role of topical antibiotics used as prophylaxis in surgical site infection prevention.

    LENUS (Irish Health Repository)

    McHugh, S M

    2011-04-01

    Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining \\'topical\\' or \\'local\\' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

  11. The role of topical antibiotics used as prophylaxis in surgical site infection prevention.

    LENUS (Irish Health Repository)

    McHugh, S M

    2012-02-01

    Compared with systemic antibiotic therapy, the topical or local delivery of an antibiotic has many potential advantages. However, local antibiotics at the surgical site have received very limited approval in any of the surgical prophylaxis consensus guidelines that we are aware of. A review of the literature was carried out through searches of peer-reviewed publications in PubMed in the English language over a 30 year period between January 1980 and May 2010. Both retrospective and prospective studies were included, as well as meta-analyses. With regard to defining \\'topical\\' or \\'local\\' antibiotic application, the application of an antibiotic solution to the surgical site intraoperatively or immediately post-operatively was included. A number of surgical procedures have been shown to significantly benefit from perioperative topical prophylaxis, e.g. joint arthroplasty, cataract surgery and, possibly, breast augmentation. In obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. The selective use of topical antibiotics as surgical prophylaxis is justified for specific procedures, such as joint arthroplasty, cataract surgery and, possibly, breast augmentation. In selective cases, such as obese patients undergoing abdominal surgery, topical surgical prophylaxis is also proven to be beneficial. Apart from these specific indications, the evidence for use of topical antibiotics in surgery is lacking in conclusive randomized controlled trials.

  12. Fungal Biotransformation of Tetracycline Antibiotics.

    Science.gov (United States)

    Shang, Zhuo; Salim, Angela A; Khalil, Zeinab; Bernhardt, Paul V; Capon, Robert J

    2016-08-01

    The commercial antibiotics tetracycline (3), minocycline (4), chlortetracycline (5), oxytetracycline (6), and doxycycline (7) were biotransformed by a marine-derived fungus Paecilomyces sp. to yield seco-cyclines A-H (9-14, 18 and 19) and hemi-cyclines A-E (20-24). Structures were assigned by detailed spectroscopic analysis, and in the case of 10 X-ray crystallography. Parallel mechanisms account for substrate-product specificity, where 3-5 yield seco-cyclines and 6 and 7 yield hemi-cyclines. The susceptibility of 3-7 to fungal biotransformation is indicative of an unexpected potential for tetracycline "degradation" (i.e., antibiotic resistance) in fungal genomes. Significantly, the fungal-derived tetracycline-like viridicatumtoxins are resistant to fungal biotransformation, providing chemical insights that could inform the development of new tetracycline antibiotics resistant to enzymatic degradation. PMID:27419475

  13. The role of watershed characteristics, permafrost thaw, and wildfire on dissolved organic carbon biodegradability and water chemistry in Arctic headwater streams

    Science.gov (United States)

    Larouche, J. R.; Abbott, B. W.; Bowden, W. B.; Jones, J. B.

    2015-07-01

    In the Alaskan Arctic, rapid climate change is increasing the frequency of disturbance including wildfire and permafrost collapse. These pulse disturbances may influence the delivery of dissolved organic carbon (DOC) to aquatic ecosystems, however the magnitude of these effects compared to the natural background variability of DOC at the watershed scale is not well known. We measured DOC quantity, composition, and biodegradability from 14 river and stream reaches (watershed sizes ranging from 1.5-167 km2) some of which were impacted by permafrost collapse (thermokarst) and fire. We found that region had a significant impact on quantity and biodegradability of DOC, likely driven by landscape and watershed characteristics such as lithology, soil and vegetation type, elevation, and glacial age. However, contrary to our hypothesis, we found that streams disturbed by thermokarst and fire did not contain significantly altered labile DOC fractions compared to adjacent reference waters, potentially due to rapid ecosystem recovery after fire and thermokarst as well as the limited spatial extent of thermokarst. Overall, biodegradable DOC ranged from 4 to 46 % and contrary to patterns of DOC biodegradability in large Arctic rivers, seasonal variation in DOC biodegradability showed no clear pattern between sites, potentially related to stream geomorphology and position along the river network. While thermokarst and fire can alter DOC quantity and biodegradability at the scale of the feature, we conclude that tundra ecosystems are resilient to these types of disturbance.

  14. The role of watershed characteristics, permafrost thaw, and wildfire on dissolved organic carbon biodegradability and water chemistry in Arctic headwater streams

    Directory of Open Access Journals (Sweden)

    J. R. Larouche

    2015-03-01

    Full Text Available In the Alaskan Arctic, rapid climate change is increasing the frequency of disturbance including wildfire and permafrost collapse. These pulse disturbances may influence the delivery of dissolved organic carbon (DOC to aquatic ecosystems, however the magnitude of these effects compared to the natural background variability of DOC at the watershed scale is not well known. We measured DOC quantity, composition, and biodegradability from 14 river and stream reaches (watershed sizes ranging from 1.5–167 km2 some of which were impacted by permafrost collapse (thermokarst and fire. We found that region had a significant impact on quantity and biodegradability of DOC, likely driven by landscape and watershed characteristics such as lithology, soil and vegetation type, elevation, and glacial age. However, contrary to our hypothesis, we found that streams disturbed by thermokarst and fire did not contain significantly altered labile DOC fractions compared to adjacent reference waters, potentially due to rapid ecosystem recovery after fire and thermokarst as well as the limited spatial extent of thermokarst. Overall, biodegradable DOC ranged from 4 to 46% and contrary to patterns of DOC biodegradability in large Arctic rivers, seasonal variation in DOC biodegradability showed no clear pattern between sites, potentially related to stream geomorphology and position along the river network. While thermokarst and fire can alter DOC quantity and biodegradability at the scale of the feature, we conclude that tundra ecosystems are resilient to these types of disturbance.

  15. Long-term effects of antibiotics on the elimination of chemical oxygen demand, nitrification, and viable bacteria in laboratory-scale wastewater treatment plants.

    Science.gov (United States)

    Schmidt, Susan; Winter, Josef; Gallert, Claudia

    2012-10-01

    Antibiotics and other pharmaceuticals are contaminants of the environment because of their widespread use and incomplete removal by microorganisms during wastewater treatment. The influence of a mixture of ciprofloxacin (CIP), gentamicin (GM), sulfamethoxazole (SMZ)/trimethoprim (TMP), and vancomycin (VA), up to a final concentration of 40 mg/L, on the elimination of chemical oxygen demand (COD), nitrification, and survival of bacteria, as well as the elimination of the antibiotics, was assessed in a long-term study in laboratory treatment plants (LTPs). In the presence of 30 mg/L antibiotics, nitrification of artificial sewage by activated sludge ended at nitrite. Nitrate formation was almost completely inhibited. No nitrification at all was possible in the presence of 40 mg/L antibiotics. The nitrifiers were more sensitive to antibiotics than heterotrophic bacteria. COD elimination in antibiotic-stressed LTPs was not influenced by ≤20 mg/L antibiotics. Addition of 30 mg/L antibiotic mixture decreased COD removal efficiency for a period, but the LTPs recovered. Similar results were obtained with 40 mg/L antibiotic mixture. The total viable count of bacteria was not affected negatively by the antibiotics. It ranged from 2.2 × 10(6) to 8.2 × 10(6) colony-forming units per milliliter (CFU/mL) compared with the control at 1.4 × 10(6)-6.3 × 10(6) CFU/mL. Elimination of the four antibiotics during phases of 2.4-30 mg/L from the liquid was high for GM (70-90 %), much lower for VA, TMP, and CIP (0-50 %), and highly fluctuating for SMZ (0-95 %). The antibiotics were mainly adsorbed to the sludge and not biodegraded. PMID:22622431

  16. Antibiotics and the resistant microbiome

    DEFF Research Database (Denmark)

    Sommer, Morten; Dantas, Gautam

    2011-01-01

    . Less appreciated are the concomitant changes in the human microbiome in response to these assaults and their contribution to clinical resistance problems. Studies have shown that pervasive changes to the human microbiota result from antibiotic treatment and that resistant strains can persist for years....... Additionally, culture-independent functional characterization of the resistance genes from the microbiome has demonstrated a close evolutionary relationship between resistance genes in the microbiome and in pathogens. Application of these techniques and novel cultivation methods are expected to significantly...... expand our understanding of the interplay between antibiotics and the microbiome....

  17. Antibiotic allergy in cystic fibrosis

    OpenAIRE

    Parmar, J.; Nasser, S.

    2005-01-01

    Allergic reactions to antibiotics are more common in cystic fibrosis (CF) than in the general population. This in part is due to the improving survival in adults with CF and the increased use of high dose intravenous antibiotics. While some are immediate anaphylaxis type (IgE mediated) reactions, the majority are late onset and may have non-specific features such as rash and fever. Piperacillin has consistently been found to have the highest rate of reported reactions (30–50%). There is a low...

  18. Biodegradable polymers in clinical use and clinical development

    CERN Document Server

    Domb, Abraham J

    2011-01-01

    The definitive guide to biodegradable polymer science-where we are and what's to come The most comprehensive review of biodegradable polymers already utilized or under development for clinical use, Biodegradable Polymers in Clinical Use and Clinical Development looks at the state of biodegradable polymers now and over the next five years. Implantable molecules that break down within the body over a predetermined period of time, biodegradable polymers have been employed as drug carriers, orthopedic fixation devices, and absorbable sutures. Yet while hundreds of such polymers have been deve

  19. Strategies for antimicrobial drug delivery to biofilm.

    Science.gov (United States)

    Martin, Claire; Low, Wan Li; Gupta, Abhishek; Amin, Mohd Cairul Iqbal Mohd; Radecka, Iza; Britland, Stephen T; Raj, Prem; Kenward, Ken M A

    2015-01-01

    Biofilms are formed by the attachment of single or mixed microbial communities to a variety of biological and/or synthetic surfaces. Biofilm micro-organisms benefit from many advantages of the polymicrobial environment including increased resistance against antimicrobials and protection against the host organism's defence mechanisms. These benefits stem from a number of structural and physiological differences between planktonic and biofilm-resident microbes, but two main factors are the presence of extracellular polymeric substances (EPS) and quorum sensing communication. Once formed, biofilms begin to synthesise EPS, a complex viscous matrix composed of a variety of macromolecules including proteins, lipids and polysaccharides. In terms of drug delivery strategies, it is the EPS that presents the greatest barrier to diffusion for drug delivery systems and free antimicrobial agents alike. In addition to EPS synthesis, biofilm-based micro-organisms can also produce small, diffusible signalling molecules involved in cell density-dependent intercellular communication, or quorum sensing. Not only does quorum sensing allow microbes to detect critical cell density numbers, but it also permits co-ordinated behaviour within the biofilm, such as iron chelation and defensive antibiotic activities. Against this backdrop of microbial defence and cell density-specific communication, a variety of drug delivery systems have been developed to deliver antimicrobial agents and antibiotics to extracellular and/or intracellular targets, or more recently, to interfere with the specific mechanisms of quorum sensing. Successful delivery strategies have employed lipidic and polymeric-based formulations such as liposomes and cyclodextrins respectively, in addition to inorganic carriers e.g. metal nanoparticles. This review will examine a range of drug delivery systems and their application to biofilm delivery, as well as pharmaceutical formulations with innate antimicrobial properties

  20. Biodegradation of chlorobenzoic acids by ligninolytic fungi

    Czech Academy of Sciences Publication Activity Database

    Muzikář, Milan; Křesinová, Zdena; Svobodová, Kateřina; Filipová, Alena; Čvančarová, Monika; Cajthamlová, Kamila; Cajthaml, Tomáš

    2011-01-01

    Roč. 196, - (2011), s. 386-394. ISSN 0304-3894 R&D Projects: GA MŠk 2B06156; GA ČR GA525/09/1058 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorobenzoic acid * Polychlorinated biphenyls * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 4.173, year: 2011

  1. Fabrication of Environmentally Biodegradable Lignin Nanoparticles

    NARCIS (Netherlands)

    Frangville, C.; Rutkevicius, M.; Richter, A.P.; Velev, O.D.; Stoyanov, S.D.; Paunov, V.N.

    2012-01-01

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The fi

  2. Natural Biodegradation of Phenolic Compounds in Groundwater

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A combination of field data and theoretical approaches is used to assess the natural attenuation and status of a complex plume of phenolic compounds (phenol, cresols, xylenols) in a deep, consolidated, UK Permo-Triassic sandstone aquifer. Biodegradation of the phenolic compounds at concentrations up to 12500mg·L-1 is occurring under aerobic, NO-3-reducing, Mn/Fe-reducing, SO2-4-reducing and methanogenic conditions in the aquifer, with the accumulation of inorganic and organic metabolites in the plume. An electron and carbon balance for the plume suggests that only 6% of the source term has been degraded in 50 years. The residual contaminant mass in the plume significantly exceeds estimates of electron acceptor inputs, indicating that the plume will grow. Two detailed vertical profiles through the plume show that contaminant distributions are controlled more by source history than by biodegradation processes. Microbiological and mass balance studies show that biodegradation is greatest at the plume fringe where contaminant concentrations are diluted by transverse mixing. Active bacterial populations exist throughout the plume but biodegradation is inhibited in the plume core by high contaminant concentrations. Stable isotope studies show that SO2-4-reduction is particularly sensitive to contaminant concentration. The aquifer is not oxidant-deficient but natural attenuation of the phenolic compounds in this system is limited by toxicity from the pollutant load and the bioavailability of electron acceptors. Natural attenuation of these contaminants will increase only after increased dilution of the plume.

  3. Biodegradable polymersomes for targeted ultrasound imaging

    NARCIS (Netherlands)

    Zhou, W.; Meng, F.; Engbers, G.H.M.; Feijen, J.

    2006-01-01

    Biodegradable polymersomes with a sub-micron size were prepared by using poly(ethylene glycol)–polylactide (PEG–PDLLA) block-copolymers in aqueous media. Air-encapsulated polymersomes could be obtained by a lyophilization/rehydration procedure. Preliminary results showed that these polymersomes were

  4. Transport of nonlinearly biodegradable contaminants in aquifers

    NARCIS (Netherlands)

    Keijzer, H.

    2001-01-01

    This thesis deals with the transport behavior of nonlinearly biodegradable contaminants in aquifers. Such transport occurs during in situ bioremediation which is based on the injection of an electron acceptor or electron donor. The main interests in this thesis are the mutual influences of underlyin

  5. Polyvinyl alcohol biodegradation under denitrifying conditions

    Czech Academy of Sciences Publication Activity Database

    Marušincová, H.; Husárová, L.; Růžička, J.; Ingr, M.; Navrátil, Václav; Buňková, L.; Koutný, M.

    2013-01-01

    Roč. 84, October (2013), s. 21-28. ISSN 0964-8305 Grant ostatní: GA ČR(CZ) GAP108/10/0200 Institutional support: RVO:61388963 Keywords : polyvinyl alcohol * biodegradation * denitrification * waste-water treatment * anaerobic * Steroidobacter Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.235, year: 2013

  6. Biodegradability of leathers through anaerobic pathway.

    Science.gov (United States)

    Dhayalan, K; Fathima, N Nishad; Gnanamani, A; Rao, J Raghava; Nair, B Unni; Ramasami, T

    2007-01-01

    Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers. PMID:16740383

  7. Biodegradable synthetic polymers for tissue engineering

    Directory of Open Access Journals (Sweden)

    Gunatillake P. A.

    2003-05-01

    Full Text Available This paper reviews biodegradable synthetic polymers focusing on their potential in tissue engineering applications. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Some disadvantages of these polymers in tissue engineering applications are their poor biocompatibility, release of acidic degradation products, poor processability and loss of mechanical properties very early during degradation. Other degradable polymers such as polyorthoesters, polyanhydrides, polyphosphazenes, and polyurethanes are also discussed and their advantages and disadvantages summarised. With advancements in tissue engineering it has become necessary to develop polymers that meet more demanding requirements. Recent work has focused on developing injectable polymer compositions based on poly (propylene fumarate and poly (anhydrides to meet these requirements in orthopaedic tissue engineering. Polyurethanes have received recent attention for development of degradable polymers because of their great potential in tailoring polymer structure to achieve mechanical properties and biodegradability to suit a variety of applications.

  8. Biodegradable Polymeric Microcapsules: Preparation and Properties

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2011-01-01

    Biodegradable polymeric microcapsules can be produced through different methods of which emulsion solvent-evaporation/extraction is frequently used. In this technique, the polymer (often polylactide) is dissolved in a good solvent and is emulsified together with a poor solvent into a nonsolvent phas

  9. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    Science.gov (United States)

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  10. Alginate based hydrogel as a potential biopolymeric carrier for drug delivery and cell delivery systems: present status and applications.

    Science.gov (United States)

    Giri, Tapan Kumar; Thakur, Deepa; Alexander, Amit; Ajazuddin; Badwaik, Hemant; Tripathi, Dulal Krishna

    2012-11-01

    Alginate is a non-toxic, biocompatible and biodegradable natural polymer with a number of peculiar physicochemical properties for which it has wide applications in drug delivery and cell delivery systems. Hydrogel formation can be obtained by interactions of anionic alginates with multivalent inorganic cations by simple ionotropic gelation method. Hydrophilic polymeric network of three dimensional cross linked structures of hydrogels absorb substantial amount of water or biological fluids. Among the numerous biomaterials used for hydrogel formation alginate has been and will continue to be one of the most important biomaterial. Therefore, in view of the vast literature support, we focus in this review on alginate - based hydrogel as drug delivery and cell delivery carriers for biomedical applications. Various properties of alginates, their hydrogels and also various techniques used for preparing alginate hydrogels have been reviewed. PMID:22998675

  11. Probiotic approach to prevent antibiotic resistance.

    Science.gov (United States)

    Ouwehand, Arthur C; Forssten, Sofia; Hibberd, Ashley A; Lyra, Anna; Stahl, Buffy

    2016-06-01

    Probiotics are live microorganisms, mainly belonging to the genera Lactobacillus and Bifidobacterium, although also strain of other species are commercialized, that have a beneficial effect on the host. From the perspective of antibiotic use, probiotics have been observed to reduce the risk of certain infectious disease such as certain types of diarrhea and respiratory tract infection. This may be accompanied with a reduced need of antibiotics for secondary infections. Antibiotics tend to be effective against most common diseases, but increasingly resistance is being observed among pathogens. Probiotics are specifically selected to not contribute to the spread of antibiotic resistance and not carry transferable antibiotic resistance. Concomitant use of probiotics with antibiotics has been observed to reduce the incidence, duration and/or severity of antibiotic-associated diarrhea. This contributes to better adherence to the antibiotic prescription and thereby reduces the evolution of resistance. To what extent probiotics directly reduce the spread of antibiotic resistance is still much under investigation; but maintaining a balanced microbiota during antibiotic use may certainly provide opportunities for reducing the spread of resistances. Key messages Probiotics may reduce the risk for certain infectious diseases and thereby reduce the need for antibiotics. Probiotics may reduce the risk for antibiotic-associated diarrhea Probiotics do not contribute to the spread of antibiotic resistance and may even reduce it. PMID:27092975

  12. Attenuation of veterinary antibiotics in full-scale vermicomposting of swine manure via the housefly larvae (Musca domestica).

    Science.gov (United States)

    Zhang, ZhiJian; Shen, JianGuo; Wang, Hang; Liu, Meng; Wu, LongHua; Ping, Fan; He, Qiang; Li, HongYi; Zheng, ChangFeng; Xu, XinHua

    2014-01-01

    Animal waste from concentrated swine farms is widely considered to be a source of environmental pollution, and the introduction of veterinary antibiotics in animal manure to ecosystems is rapidly becoming a major public health concern. A housefly larvae (Musca domestica) vermireactor has been increasingly adopted for swine manure value-added bioconversion and pollution control, but few studies have investigated its efficiency on antibiotic attenuation during manure vermicomposting. In this study we explored the capacity and related attenuation mechanisms of antibiotic degradation and its linkage with waste reduction by field sampling during a typical cycle (6 days) of full-scale larvae manure vermicomposting. Nine antibiotics were dramatically removed during the 6-day vermicomposting process, including tetracyclines, sulfonamides, and fluoroquinolones. Of these, oxytetracycline and ciprofloxacin exhibited the greater reduction rate of 23.8 and 32.9 mg m(-2), respectively. Environmental temperature, pH, and total phosphorus were negatively linked to the level of residual antibiotics, while organic matter, total Kjeldahl nitrogen, microbial respiration intensity, and moisture exhibited a positive effect. Pyrosequencing data revealed that the dominant phyla related to Firmicutes, Bacteroidetes, and Proteobacteria accelerated manure biodegradation likely through enzyme catalytic reactions, which may enhance antibiotic attenuation during vermicomposting. PMID:25354896

  13. Attenuation of veterinary antibiotics in full-scale vermicomposting of swine manure via the housefly larvae (Musca domestica)

    Science.gov (United States)

    Zhang, Zhijian; Shen, Jianguo; Wang, Hang; Liu, Meng; Wu, Longhua; Ping, Fan; He, Qiang; Li, Hongyi; Zheng, Changfeng; Xu, Xinhua

    2014-10-01

    Animal waste from concentrated swine farms is widely considered to be a source of environmental pollution, and the introduction of veterinary antibiotics in animal manure to ecosystems is rapidly becoming a major public health concern. A housefly larvae (Musca domestica) vermireactor has been increasingly adopted for swine manure value-added bioconversion and pollution control, but few studies have investigated its efficiency on antibiotic attenuation during manure vermicomposting. In this study we explored the capacity and related attenuation mechanisms of antibiotic degradation and its linkage with waste reduction by field sampling during a typical cycle (6 days) of full-scale larvae manure vermicomposting. Nine antibiotics were dramatically removed during the 6-day vermicomposting process, including tetracyclines, sulfonamides, and fluoroquinolones. Of these, oxytetracycline and ciprofloxacin exhibited the greater reduction rate of 23.8 and 32.9 mg m-2, respectively. Environmental temperature, pH, and total phosphorus were negatively linked to the level of residual antibiotics, while organic matter, total Kjeldahl nitrogen, microbial respiration intensity, and moisture exhibited a positive effect. Pyrosequencing data revealed that the dominant phyla related to Firmicutes, Bacteroidetes, and Proteobacteria accelerated manure biodegradation likely through enzyme catalytic reactions, which may enhance antibiotic attenuation during vermicomposting.

  14. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    Science.gov (United States)

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor. PMID:12491727

  15. Improving the biodegradative capacity of subsurface bacteria

    International Nuclear Information System (INIS)

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

  16. Biodegradation of natural oils in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Al-Darbi, M.M.; Saeed, N.O.; Islam, M.R. [Dalhousie University, Halifax, NS (Canada). Faculty of Engineering; Lee, K. [Bedford Institute of Oceanography, Dartmouth, NS (Canada)

    2005-01-15

    Spills of non-petroleum hydrocarbons including oils and fish oils are of environmental concern because of their potential to cause serious effects on marine life and coastal environments. Biodegradation by indigenous microorganisms is an important and potentially ubiquitous process affecting both the chemical composition and physical properties of contaminant oils. Data on the environmental persistence of non-petroleum oils is now required for risk assessments and decision making by spill responders. This article investigates the biodegradability of various vegetable and fish oils under the influence of natural bacteria in seawater. The influence of nutrients and microbial environment on changes in bacterial numbers and the extent and rate of degradation for various test oils (olive, mustard, canola and cod liver oils) were studied over time. Time-series visual and microscopic observations were made to characterize physical changes in the residual oils, formation of floating and precipitate particles, oil droplets and dispersion. The biodegradation process was significantly influenced by environmental conditions, with a higher rate and extent of biodegradation observed in seawater amended with nutrients and wastewater that contained elevated numbers of bacteria and nutrients. It was observed that different oils respond in different rates and extents to biodegradation depending on their stability, viscosity and compositions. All results clearly revealed a significant response of the oil-contaminated samples to both the seawater and wastewater environments. Observations on changes in the physical properties of the residual oil may be important in the context of oil spill response strategies. For example, simple physical recovery methods may be used to recover polymeric lumps at the sea surface. (author)

  17. Improving the biodegradative capacity of subsurface bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  18. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  19. Use of Antibiotics in Children

    DEFF Research Database (Denmark)

    Pottegård, Anton; Broe, Anne; Aabenhus, Rune;

    2015-01-01

    Background: We aimed to describe the use of systemic antibiotics among children in Denmark. Methods: National data on drug use in Denmark were extracted from the Danish National Prescription Database. We used prescription data for all children in Denmark aged 0 to 11 years from January 1, 2000 to...

  20. ANTIBIOTIC THERAPY FOR ENT INFECTIONS

    Directory of Open Access Journals (Sweden)

    A. B. Turovsky

    2014-07-01

    Full Text Available The paper outlines basic principles of and new approaches to antibiotic therapy for ENT and upper respiratory tract infections, from point of view of the authors, on the basis of the data available in Russian and foreign literature.

  1. Antibiotics and the burn patient.

    Science.gov (United States)

    Ravat, François; Le-Floch, Ronan; Vinsonneau, Christophe; Ainaud, Pierre; Bertin-Maghit, Marc; Carsin, Hervé; Perro, Gérard

    2011-02-01

    Infection is a major problem in burn care and especially when it is due to bacteria with hospital-acquired multi-resistance to antibiotics. Moreover, when these bacteria are Gram-negative organisms, the most effective molecules are 20 years old and there is little hope of any new product available even in the distant future. Therefore, it is obvious that currently available antibiotics should not be misused. With this aim in mind, the following review was conducted by a group of experts from the French Society for Burn Injuries (SFETB). It examined key points addressing the management of antibiotics for burn patients: when to use or not, time of onset, bactericidia, combination, adaptation, de-escalation, treatment duration and regimen based on pharmacokinetic and pharmacodynamic characteristics of these compounds. The authors also considered antibioprophylaxis and some other key points such as: infection diagnosis criteria, bacterial inoculae and local treatment. French guidelines for the use of antibiotics in burn patients have been designed up from this work. PMID:20510518

  2. Do We Need New Antibiotics?

    Czech Academy of Sciences Publication Activity Database

    Spížek, Jaroslav; Novotná, Jitka; Janata, Jiří

    Seoul : COEX Convention and Exhibition Center , 2009. s. 218-218. [Annual World Congress of Industrial Biotechnology 2009 /2./. 05.04.2009-07.04.2009, Seoul] R&D Projects: GA AV ČR IAA500200810 Institutional research plan: CEZ:AV0Z50200510 Keywords : antibiotics Subject RIV: EE - Microbiology, Virology

  3. Antibiotic associated diarrhoea: Infectious causes

    Directory of Open Access Journals (Sweden)

    Ayyagari A

    2003-01-01

    Full Text Available Nearly 25% of antibiotic associated diarrhoeas (AAD is caused by Clostridium difficile, making it the commonest identified and treatable pathogen. Other pathogens implicated infrequently include Clostridium perfringens, Staphylococcus aureus, Klebsiella oxytoca, Candida spp. and Salmonella spp. Most mild cases of AAD are due to non-infectious causes which include reduced break down of primary bile acids and decrease metabolism of carbohydrates, allergic or toxic effects of antibiotic on intestinal mucosa and pharmacological effect on gut motility. The antibiotics most frequently associated with C. difficile associated diarrhoea are clindamycin, cephalosporin, ampicillin and amoxicillin. Clinical presentation may vary from mild diarrhoea to severe colitis and pseudomembranous colitis associated with high morbidity and mortality. The most sensitive and specific diagnostic test for C. difficile infection is tissue culture assay for cytotoxicity of toxin B. Commercial ELISA kits are available. Though less sensitive, they are easy to perform and are rapid. Withdrawal of precipitating antibiotic is all that is needed for control of mild to moderate cases. For severe cases of AAD, oral metronidazole is the first line of treatment, and oral vancomycin is the second choice. Probiotics have been used for recurrent cases.

  4. Antibiotic resistance pattern in uropathogens

    OpenAIRE

    Gupta V; Yadav A; Joshi R

    2002-01-01

    Uropathogenic strains from inpatient and outpatient departments were studied from April 1997 to March 1999 for their susceptibility profiles. The various isolates were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter baumanii and Enterococcus faecalis. Antibiotic susceptibility pattern of these isolates revealed that for outpatients, first generation cephalosporins, nitrofurantoin, norfloxacin/ciprofloxacin were effective for treatment of urina...

  5. A study of antibiotic prescribing

    DEFF Research Database (Denmark)

    Jaruseviciene, L.; Radzeviciene-Jurgute, R.; Jurgutis, A.; Lazarus, J.V.; Ovhed, I.; Strandberg, E.L.; Bjerrum, L.

    2012-01-01

    clinically or pharmacologically. Methods. 22 Lithuanian and 29 Russian GPs participated in five focus group discussions. Thematic analysis was used to analyse the data. Results. We identified four main thematic categories: patients' faith in antibiotics as medication for upper respiratory tract infections...

  6. Antibiotics, Formula Feeding Might Change Baby's 'Microbiome'

    Science.gov (United States)

    ... nih.gov/medlineplus/news/fullstory_159392.html Antibiotics, Formula Feeding Might Change Baby's 'Microbiome' C-section birth ... microbiomes" are altered by cesarean births, antibiotics and formula feeding. "The microbiome is really important in how ...

  7. Antibiotic 'Report Card' Drills Guidelines into Dentists

    Science.gov (United States)

    ... 160702.html Antibiotic 'Report Card' Drills Guidelines Into Dentists Seeing their prescription rates leads some to change ... 30, 2016 TUESDAY, Aug. 30, 2016 (HealthDay News) -- Dentists are less likely to prescribe antibiotics for patients ...

  8. FDA Bolsters Warnings about Class of Antibiotics

    Science.gov (United States)

    ... html FDA Bolsters Warnings About Class of Antibiotics Fluoroquinolones such as Cipro, Levaquin should be reserved for ... label warnings on a class of antibiotics called fluoroquinolones because the drugs can lead to disabling side ...

  9. Danger of Antibiotic Overuse (For Parents)

    Science.gov (United States)

    ... don’t work against them. This is called bacterial resistance or antibiotic resistance. Treating these resistant bacteria requires ... child gets sick? To minimize the risk of bacterial resistance, keep these tips in mind: Take antibiotics only ...

  10. Antibiotic and Antimicrobial Resistance: Threat Report 2013

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Antibiotic Resistance Threats in the United States, 2013 Recommend on Facebook Tweet Share Compartir This report, Antibiotic resistance threats in the United States, 2013 gives a first- ...

  11. Chitosan: a propitious biopolymer for drug delivery.

    Science.gov (United States)

    Duttagupta, Dibyangana S; Jadhav, Varsha M; Kadam, Vilasrao J

    2015-01-01

    Scientists have always been interested in the use of natural polymers for drug delivery. Chitosan, being a natural cationic polysaccharide has received a great deal of attention in the past few years. It is obtained by deacetylation of chitin and is regarded as the second most ubiquitous polymer subsequent to cellulose on earth. Unlike other natural polymers, the cationic charge possessed by chitosan is accountable for imparting interesting physical and chemical properties. Chitosan has been widely exploited for its mucoadhesive character, permeation enhancing properties and controlled release of drugs. Moreover it's non-toxic, biocompatible and biodegradable properties make it a good candidate for novel drug delivery system. This review provides an insight on various chitosan based formulations for drug delivery. Some of the current applications of chitosan in areas like ophthalmic, nasal, buccal, sublingual, gastro-retentive, pulmonary, transdermal, colon-specific and vaginal drug delivery have been discussed. In addition, active targeting of drugs to tumor cells using chitosan has been described. Lastly a brief section covering the safety aspects of chitosan has also been reviewed. PMID:25761010

  12. Drug delivery systems in domestic animal species.

    Science.gov (United States)

    Brayden, David J; Oudot, Emilie J M; Baird, Alan W

    2010-01-01

    Delivery of biologically active agents to animals is often perceived to be the poor relation of human drug delivery. Yet this field has a long and successful history of species-specific device and formulation development, ranging from simple approaches and devices used in production animals to more sophisticated formulations and approaches for a wide range of species. While several technologies using biodegradable polymers have been successfully marketed in a range of veterinary and human products, the transfer of delivery technologies has not been similarly applied across species. This may be due to a combination of specific technical requirements for use of devices in different species, inter-species pharmacokinetic, pharmacodynamic and physiological differences, and distinct market drivers for drug classes used in companion and food-producing animals. This chapter reviews selected commercialised and research-based parenteral and non-parenteral veterinary drug delivery technologies in selected domestic species. Emphasis is also placed on the impact of endogenous drug transporters on drug distribution characteristics in different species. In vitro models used to investigate carrier-dependent transport are reviewed. Species-specific expression of transporters in several tissues can account for inter-animal or inter-species pharmacokinetic variability, lack of predictability of drug efficacy, and potential drug-drug interactions. PMID:20204584

  13. Genetically engineered nanocarriers for drug delivery

    Directory of Open Access Journals (Sweden)

    Shi P

    2014-03-01

    Full Text Available Pu Shi, Joshua A Gustafson, J Andrew MacKayDepartment of Pharmacology and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USAAbstract: Cytotoxicity, low water solubility, rapid clearance from circulation, and off-target side-effects are common drawbacks of conventional small-molecule drugs. To overcome these shortcomings, many multifunctional nanocarriers have been proposed to enhance drug delivery. In concept, multifunctional nanoparticles might carry multiple agents, control release rate, biodegrade, and utilize target-mediated drug delivery; however, the design of these particles presents many challenges at the stage of pharmaceutical development. An emerging solution to improve control over these particles is to turn to genetic engineering. Genetically engineered nanocarriers are precisely controlled in size and structure and can provide specific control over sites for chemical attachment of drugs. Genetically engineered drug carriers that assemble nanostructures including nanoparticles and nanofibers can be polymeric or non-polymeric. This review summarizes the recent development of applications in drug and gene delivery utilizing nanostructures of polymeric genetically engineered drug carriers such as elastin-like polypeptides, silk-like polypeptides, and silk-elastin-like protein polymers, and non-polymeric genetically engineered drug carriers such as vault proteins and viral proteins.Keywords: polymeric drug carrier, non-polymeric drug carrier, gene delivery, GE drug carriers

  14. Cell and biomolecule delivery for regenerative medicine

    International Nuclear Information System (INIS)

    Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix) delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell-material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine. (topical review)

  15. Cell and biomolecule delivery for regenerative medicine

    Directory of Open Access Journals (Sweden)

    Ian O Smith and Peter X Ma

    2010-01-01

    Full Text Available Regenerative medicine is an exciting field that aims to create regenerative alternatives to harvest tissues for transplantation. In this approach, the delivery of cells and biological molecules plays a central role. The scaffold (synthetic temporary extracellular matrix delivers cells to the regenerative site and provides three-dimensional environments for the cells. To fulfil these functions, we design biodegradable polymer scaffolds with structural features on multiple size scales. To enhance positive cell–material interactions, we design nano-sized structural features in the scaffolds to mimic the natural extracellular matrix. We also integrate micro-sized pore networks to facilitate mass transport and neo tissue regeneration. We also design novel polymer devices and self-assembled nanospheres for biomolecule delivery to recapitulate key events in developmental and wound healing processes. Herein, we present recent work in biomedical polymer synthesis, novel processing techniques, surface engineering and biologic delivery. Examples of enhanced cellular/tissue function and regenerative outcomes of these approaches are discussed to demonstrate the excitement of the biomimetic scaffold design and biologic delivery in regenerative medicine.

  16. Antibiotics: Use and misuse in pediatric dentistry

    OpenAIRE

    F C Peedikayil

    2011-01-01

    Antibiotics are commonly used in dentistry for prophylactic as well as for therapeutic purposes. Most often antibiotics are used in unwarranted situations, which may give rise to resistant bacterial strains. Dentists want to make their patients well and to prevent unpleasant complications. These desires, coupled with the belief that many oral problems are infectious, stimulate the prescribing of antibiotics. Good knowledge about the indications of antibiotics is the need of the hour in prescr...

  17. Squalamine: an aminosterol antibiotic from the shark.

    OpenAIRE

    Moore, K.S.; Wehrli, S; Roder, H; Rogers, M.; Forrest, J N; McCrimmon, D; Zasloff, M.

    1993-01-01

    In recent years, a variety of low molecular weight antibiotics have been isolated from diverse animal species. These agents, which include peptides, lipids, and alkaloids, exhibit antibiotic activity against environmental microbes and are thought to play a role in innate immunity. We report here the discovery of a broad-spectrum steroidal antibiotic isolated from tissues of the dogfish shark Squalus acanthias. This water-soluble antibiotic, which we have named squalamine, exhibits potent bact...

  18. Antibiotic Resistance of Shigella Species in Iran

    Directory of Open Access Journals (Sweden)

    A.Mehr-Movahed

    1987-07-01

    Full Text Available Antibiotic resistance in Shigella species has been showing a rising trend all over the world. This study was performed to discover the state of antibiotic resistance of Shigella species with regards to six common antibiotics in use in Iran.

  19. Permeation measurement of gestodene for some biodegradable materials using Franz diffusion cells.

    Science.gov (United States)

    Liu, Danhua; Zhang, Chong; Zhang, Xiaowei; Zhen, Zhu; Wang, Ping; Li, Jianxin; Yi, Dongxu; Jin, Ying; Yang, Dan

    2015-09-01

    Biodegradable poly(d,l-lactide) (PDLLA), Poly(trimethylene carbonate) (PTMC), polycaprolactone (PCL), poly(caprolactone-co-d,l-lactide) (PCDLLA) and poly(trimethylene carbonate-co-caprolactone) (PTCL) are recently used for clinical drug delivery system such as subcutaneous contraceptive implant capsule due to their biodegradable properties that they could possess long-term stable performance in vivo without removal, however their permeation rate is unknown. In the work, biodegradable material membranes were prepared by solvent evaporation using chloroform, and commercial silicone rubber membrane served as a control. Gestodene was used as a model drug. Gestodene has high biologic progestational activity which allows for high contraceptive reliability at very low-dose levels. The permeation rate of gestodene for several biodegradable materials was evaluated. In vitro diffusion studies were done using Franz diffusion cells with a diffusion area of 1.33 cm(2). Phosphate buffer solution (PBS, pH 7.4), 10% methanol solution and distilled water were taken in donor and receiver chambers at temperature of 37 °C respectively. The in vitro experiments were conducted over a period of 24 h during which samples were collected at regular intervals. The withdrawn samples were appropriately diluted and measured on UV-vis spectrophotometer at 247 nm. Conclusion data from our study showed that permeation rate of PCDLLA with CL ratio more than 70% could be more excellent than commercial silicone rubber membrane. They may be suitable as a candidate carrier for gestodene subcutaneous contraceptive implants in contraceptive fields. PMID:27134544

  20. Stability studies of a somatostatin analogue in biodegradable implants.

    Science.gov (United States)

    Rothen-Weinhold, A; Besseghir, K; Vuaridel, E; Sublet, E; Oudry, N; Gurny, R

    1999-02-15

    In recent years, peptides and proteins have received much attention as drug candidates. For many polypeptides, particularly hormones, it is desirable to release the drug continuously at a controlled rate over a period of weeks or even months, and thus a controlled release system is needed. Polylactic acid (PLA) is a biocompatible and biodegradable material with wide utility for many applications, including the design of controlled release systems for pharmaceutical agents. Pharmaceutical development of these delivery systems presents new problems in the area of stability assessment, especially for peptide drugs. In this study, we aimed to investigate the influence of different steps, during the manufacturing of an implant, on peptide stability in the polymeric matrix. Polylactic acid implants containing vapreotide, a somatostatin analogue, were prepared by extrusion. The effects of time, extrusion and temperature on the peptide stability were studied. The influence of various gamma sterilization doses, as well as the conditions under which the implants were irradiated, were also investigated. Peptide stability in the polymeric matrix was evaluated at various temperatures and at various time intervals up to 9 months. PMID:10205641

  1. Treatment of osteomyelitis with antibiotic-soaked porous glass ceramic.

    Science.gov (United States)

    Kawanabe, K; Okada, Y; Matsusue, Y; Iida, H; Nakamura, T

    1998-05-01

    We have developed a new drug delivery system using porous apatite-wollastonite glass ceramic (A-W GC) to treat osteomyelitis. A-W GC (porosity, 70% and 20% to 30%), or porous hydroxyapatite (HA) blocks (porosity 35% to 48%) used as controls, were soaked in mixtures of two antibiotics, isepamicin sulphate (ISP) and cefmetazole (CMZ) under high vacuum. We evaluated the release concentrations of the antibiotics from the blocks. The bactericidal concentration of ISP from A-W GC was maintained for more than 42 days, but that from HA decreased to below the detection limit after 28 days. The concentrations of CMZ from both materials were lower than those of ISP. An in vivo study using rabbit femora showed that an osseous concentration of ISP was maintained at eight weeks after implantation. Osteoconduction of the A-W GC block was good. Four patients with infected hip arthroplasties and one with osteomyelitis of the tibia have been treated with the new delivery system with excellent results. PMID:9619951

  2. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    International Nuclear Information System (INIS)

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  3. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ju; Kim, Young-Jin [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.k [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of)

    2009-08-15

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  4. Excretion of Antibiotic Resistance Genes by Dairy Calves Fed Milk Replacers with Varying Doses of Antibiotics

    OpenAIRE

    Thames, Callie H; Pruden, Amy; James, Robert E.; Ray, Partha P.; Knowlton, Katharine F.

    2012-01-01

    Elevated levels of antibiotic resistance genes (ARGs) in soil and water have been linked to livestock farms and in some cases feed antibiotics may select for antibiotic resistant gut microbiota. The purpose of this study was to examine the establishment of ARGs in the feces of calves receiving milk replacer containing no antibiotics versus subtherapeutic or therapeutic doses of tetracycline and neomycin. The effect of antibiotics on calf health was also of interest. Twenty-eight male and fema...

  5. Surface modeling of soil antibiotics.

    Science.gov (United States)

    Shi, Wen-jiao; Yue, Tian-xiang; Du, Zheng-ping; Wang, Zong; Li, Xue-wen

    2016-02-01

    Large numbers of livestock and poultry feces are continuously applied into soils in intensive vegetable cultivation areas, and then some veterinary antibiotics are persistent existed in soils and cause health risk. For the spatial heterogeneity of antibiotic residues, developing a suitable technique to interpolate soil antibiotic residues is still a challenge. In this study, we developed an effective interpolator, high accuracy surface modeling (HASM) combined vegetable types, to predict the spatial patterns of soil antibiotics, using 100 surface soil samples collected from an intensive vegetable cultivation area located in east of China, and the fluoroquinolones (FQs), including ciprofloxacin (CFX), enrofloxacin (EFX) and norfloxacin (NFX), were analyzed as the target antibiotics. The results show that vegetable type is an effective factor to be combined to improve the interpolator performance. HASM achieves less mean absolute errors (MAEs) and root mean square errors (RMSEs) for total FQs (NFX+CFX+EFX), NFX, CFX and EFX than kriging with external drift (KED), stratified kriging (StK), ordinary kriging (OK) and inverse distance weighting (IDW). The MAE of HASM for FQs is 55.1 μg/kg, and the MAEs of KED, StK, OK and IDW are 99.0 μg/kg, 102.8 μg/kg, 106.3 μg/kg and 108.7 μg/kg, respectively. Further, RMSE simulated by HASM for FQs (CFX, EFX and NFX) are 106.2 μg/kg (88.6 μg/kg, 20.4 μg/kg and 39.2 μg/kg), and less 30% (27%, 22% and 36%), 33% (27%, 27% and 43%), 38% (34%, 23% and 41%) and 42% (32%, 35% and 51%) than the ones by KED, StK, OK and IDW, respectively. HASM also provides better maps with more details and more consistent maximum and minimum values of soil antibiotics compared with the measured data. The better performance can be concluded that HASM takes the vegetable type information as global approximate information, and takes local sampling data as its optimum control constraints. PMID:26613514

  6. Mucoadhesive and muco-penetrating delivery systems for eradication of helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Saahil Arora

    2012-01-01

    Full Text Available Helicobacter pylori (H. pylori, the major culprit for peptic ulcer, has a unique way of survival in harsh acidic environment of the stomach by colonizing deep in the gastric mucosal layer. Failure of conventional therapies against H. pylori for complete eradication has major limitations like low residence time of delivery system in stomach, poor penetration of drug in gastric mucosa, acidic degradation of antibiotics, and development of antibiotics resistance. The poor penetration of antibiotics through thick viscoelastic mucosal gel results in incomplete eradication of H. pylori. Various investigators have formulated novel gastro-retentive drug delivery systems such as floating systems, mucoadhesive systems, pH-sensitive gel systems, and muco-penetrating delivery systems for increasing the concentration of antibiotic in close proximity to the site of H. pylori infection. This review summarizes the novel drug delivery approaches investigated during the last few years and suggests that a high eradication rate can be achieved by therapy comprising of muco-penetrating delivery systems of antibiotics against H. pylori.

  7. Synthesis and biocompatibility of a biodegradable and functionalizable thermo-sensitive hydrogel.

    Science.gov (United States)

    Sinha, Mantosh K; Gao, Jin; Stowell, Chelsea E T; Wang, Yadong

    2015-09-01

    Injectable thermal gels are a useful tool for drug delivery and tissue engineering. However, most thermal gels do not solidify rapidly at body temperature (37°C). We addressed this by synthesizing a thermo-sensitive, rapidly biodegrading hydrogel. Our hydrogel, poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane) (EPSHU), is an ABA block copolymer comprising A, methoxy poly ethylene glycol group and B, poly (propanol L-serinate hexamethylene urethane). EPSHU was characterized by gel permeation chromatography for molecular weight and (1)H NMR and Fourier transformed infrared for structure. Rheological studies measured the phase transition temperature. In vitro degradation in cholesterol esterase and in Dulbecco's phosphate buffered saline (DPBS) was tracked using the average molecular weight measured by gel permeation chromatography. LIVE/DEAD and resazurin reduction assays performed on NIH 3T3 fibroblasts exposed to EPSHU extracts demonstrated no cytotoxicity. Subcutaneous implantation into BALB/cJ mice indicated good biocompatibility in vivo. The biodegradability and biocompatibility of EPSHU together make it a promising candidate for drug delivery applications that demand carrier gel degradation within months. PMID:26814023

  8. Biodegradable microsphere-mediated cell perforation in microfluidic channel using femtosecond laser

    Science.gov (United States)

    Ishii, Atsuhiro; Ariyasu, Kazumasa; Mitsuhashi, Tatsuki; Heinemann, Dag; Heisterkamp, Alexander; Terakawa, Mitsuhiro

    2016-05-01

    The use of small particles has expanded the capability of ultrashort pulsed laser optoinjection technology toward simultaneous treatment of multiple cells. The microfluidic platform is one of the attractive systems that has obtained synergy with laser-based technology for cell manipulation, including optoinjection. We have demonstrated the delivery of molecules into suspended-flowing cells in a microfluidic channel by using biodegradable polymer microspheres and a near-infrared femtosecond laser pulse. The use of polylactic-co-glycolic acid microspheres realized not only a higher optoinjection ratio compared to that with polylactic acid microspheres but also avoids optical damage to the microfluidic chip, which is attributable to its higher optical intensity enhancement at the localized spot under a microsphere. Interestingly, optoinjection ratios to nucleus showed a difference for adhered cells and suspended cells. The use of biodegradable polymer microspheres provides high throughput optoinjection; i.e., multiple cells can be treated in a short time, which is promising for various applications in cell analysis, drug delivery, and ex vivo gene transfection to bone marrow cells and stem cells without concerns about residual microspheres.

  9. Development and characterization of drug-loaded biodegradable PLA microcarriers prepared by the electrospraying technique.

    Science.gov (United States)

    Lu, Jian; Hou, Ren; Yang, Zhenlei; Tang, Zhihong

    2015-07-01

    Biodegradable particles are extremely useful in the development of novel drug delivery systems. Recent studies have suggested that morphology can influence the mechanisms of drug delivery in many ways. In the present study, biodegradable microparticles with different morphologies were prepared from poly(L‑lactide) (PLA) using the electrospraying technique. The microparticles were then systematically examined by scanning using an electron microscope. The results revealed that the preparation of drug-loaded microspheres through electrospraying is a simple and efficient method, and the processing parameters, such as polymer molecular weight, concentration, surfactant and solvent play an important role in obtaining high quality microcarriers. The association between microcarrier morphology and the processing parameters used was also investigated. Rifampin-loaded PLA microspheres were also prepared according to the above-mentioned model. Our data demonstrate that the drug release from PLA microspheres can be sustained in vitro for over 60 h. Our study focused on obtaining electrosprayed medicated microparticles from complex polyester particles. Further studies are required to explore the potential commercial use of these microparticles. PMID:25955135

  10. Toxicity evaluation of biodegradable chitosan nanoparticles using a zebrafish embryo model

    Directory of Open Access Journals (Sweden)

    Hu YL

    2011-12-01

    Full Text Available Yu-Lan Hu1, Wang Qi1, Feng Han2, Jian-Zhong Shao3, Jian-Qing Gao11Institute of Pharmaceutics, College of Pharmaceutical Sciences, 2Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, 3College of Life Sciences, Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang, People's Republic of ChinaBackground: Although there are a number of reports regarding the toxicity evaluation of inorganic nanoparticles, knowledge on biodegradable nanomaterials, which have always been considered safe, is still limited. For example, the toxicity of chitosan nanoparticles, one of the most widely used drug/gene delivery vehicles, is largely unknown. In the present study, the zebrafish model was used for a safety evaluation of this nanocarrier.Methods: Chitosan nanoparticles with two particle sizes were prepared by ionic cross-linking of chitosan with sodium tripolyphosphate. Chitosan nanoparticles of different concentrations were incubated with zebrafish embryos, and ZnO nanoparticles were used as the positive control.Results: Embryo exposure to chitosan nanoparticles and ZnO nanoparticles resulted in a decreased hatching rate and increased mortality, which was concentration-dependent. Chitosan nanoparticles at a size of 200 nm caused malformations, including a bent spine, pericardial edema, and an opaque yolk in zebrafish embryos. Furthermore, embryos exposed to chitosan nanoparticles showed an increased rate of cell death, high expression of reactive oxygen species, as well as overexpression of heat shock protein 70, indicating that chitosan nanoparticles can cause physiological stress in zebrafish. The results also suggest that the toxicity of biodegradable nanocarriers such as chitosan nanoparticles must be addressed, especially considering the in vivo distribution of these nanoscaled particles.Conclusion: Our results add new insights into the potential toxicity of nanoparticles produced by

  11. Starch-based completely biodegradable polymer materials

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Starch is a natural polymer which possesses many unique properties and some shortcoming simultaneously. Some synthetic polymers are biodegradable and can be tailor-made easily. Therefore, by combining the individual advantages of starch and synthetic polymers, starch-based completely biodegradable polymers (SCBP are potential for applications in biomedical and environmental fields. Therefore it received great attention and was extensively investigated. In this paper, the structure and characteristics of starch and some synthetic degradable polymers are briefly introduced. Then, the recent progress about the preparation of SCBP via physical blending and chemical modification is reviewed and discussed. At last, some examples have been presented to elucidate that SCBP are promising materials for various applications and their development is a good solution for reducing the consumption of petroleum resources and environmental problem.

  12. Biodegradable Epoxy Networks Cured with Polypeptides

    Science.gov (United States)

    Nakamura, Shigeo; Kramer, Edward J.

    2006-03-01

    Epoxy resins are used widely for adhesives as well as coatings. However, once cured they are usually highly cross-linked and are not biodegradable. To obtain potentially biodegradable polypeptides that can cure with epoxy resins and achieve as good properties as the conventional phenol novolac hardeners, poly(succinimide-co-tyrosine) was synthesized by thermal polycondensation of L-aspartic acid and L-tyrosine with phosphoric acid under reduced pressure. The tyrosine/succinimide ratio in the polypeptide was always lower than the tyrosine/(aspartic acid) feed ratio and was influenced by the synthesis conditions. Poly(succinimide-tyrosine- phenylalanine) was also synthesized from L-aspartic acid, L- tyrosine and L-phenylalanine. The thermal and mechanical properties of epoxy resins cured with these polypeptides are comparable to those of similar resins cured with conventional hardeners. In addition, enzymatic degradability tests showed that Chymotrypsin or Subtilisin A could cleave cured films in an alkaline borate buffer.

  13. Anaerobic Biodegradability of Agricultural Renewable Fibers

    OpenAIRE

    Shi, Bo; Lortscher, Peter; Palfery, Doris

    2013-01-01

    Natural fiber-based paper and paperboard products are likely disposed of in municipal wastewater, composting, or landfill after an intended usage. However, there are few studies reporting anaerobic sludge digestion and biodegradability of agricultural fibers although the soiled sanitary products, containing agricultural fibers, are increasingly disposed of in municipal wastewater or conventional landfill treatment systems, in which one or more unit operations are anaerobic digestion. We condu...

  14. Assessment of polymer-based nanocomposites biodegradability

    OpenAIRE

    Machado, A.V.; Araújo, Andreia Isabel Silva; Oliveira, Manuel

    2015-01-01

    The management of solid waste is a growing concern in many countries. Municipal solid waste is a major component of the total solid waste generated by society, and the composting of municipal solid waste has gained some attention even though a composting treatment for it is not yet widespread. It may not be realistic to replace large portions of these plastics with biodegradable materials, and it may be more important to separate plastics unsuitable for the composting process at the generatin...

  15. Biodegradation of Petroleum Hydrocarbons in Soil

    OpenAIRE

    MR Mehrasbi; B Haghighi; M.Shariat; S Naseri; Naddafi, K

    2003-01-01

    Biodegradation of petroleum hydrocarbons (20 g/kg dw soil) was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil) are 60 %, 36 % and 55 %, respectively. Dehydrogenas...

  16. Use of antibiotics in plant agriculture.

    Science.gov (United States)

    Stockwell, V O; Duffy, B

    2012-04-01

    Antibiotics are essential for control of bacterial diseases of plants, especially fire blight of pear and apple and bacterial spot of peach. Streptomycin is used in several countries; the use of oxytetracycline, oxolinic acid and gentamicin is limited to only a few countries. Springtime antibiotic sprays suppress pathogen growth on flowers and leaf surfaces before infection; after infection, antibiotics are ineffective. Antibiotics are applied when disease risk is high, and consequently the majority of orchards are not treated annually. In 2009 in the United States, 16,465 kg (active ingredient) was applied to orchards, which is 0.12% of the total antibiotics used in animal agriculture. Antibiotics are active on plants for less than a week, and significant residues have not been found on harvested fruit. Antibiotics have been indispensable for crop protection in the United States for more than 50 years without reports of adverse effects on human health or persistent impacts on the environment. PMID:22849276

  17. Synthesis, and Characterization, and Evaluation of Cellular Effects of the FOL-PEG-g-PEI-GAL Nanoparticles as a Potential Non-Viral Vector for Gene Delivery

    OpenAIRE

    S. Ghiamkazemi; Amanzadeh, A.; Dinarvand, R.; M Rafiee-Tehrani; Amini, M.

    2010-01-01

    In this manuscript, we synthesized the potential non viral vector for gene delivery with proper transfection efficiency and low cytotoxicity. Polyethylenimine (PEI) is a well-known cationic polymer which has high positive surface charge for condensing plasmid DNA. However; it is highly cytotoxic in many cell lines because of the high surface charge, non-biodegradability and non-biocompatibility. To enhance PEI biodegradability, the graft copolymer “PEG-g-PEI” was synthesized. To t...

  18. Biodegradation of tert-butylphenyl diphenyl phosphate

    International Nuclear Information System (INIS)

    The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [14C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14CO2. Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14CO2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14CO2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

  19. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  20. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    International Nuclear Information System (INIS)

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications

  1. Macmillan ring-free oil biodegradation project

    International Nuclear Information System (INIS)

    Crude oil processing at the Macmillan Ring-Free Oil Company facility (Macmillan Oil Refinery) began in approximately 1929. Operations produced naphtha, diesel fuel, insulating oil, lubricating oil, and asphalt until approximately 1987. The waste material generated by the process was Resource Conservation and Recovery Act (RCRA) listed waste K048-Dissolved Air Flotation (DAF) float containing volatile and semivolatile organic compounds. On-site unlined surface impoundments used to store DAF and crude oil wastes have periodically overflowed and contaminated two adjacent creeks. A series of extensive site investigation activities in 1992 and 1993 addressed tank and drum, asbestos, lagoon and groundwater contamination at the site. The results of the investigation indicated that the majority of the contamination is contained within 10 lagoons and surrounding soils. Volume calculations indicate that approximately 45,000 cubic yards of contaminated soils and sediments required treatment. A field simulation of biodegradation of these wastes in a land treatment unit was implemented during removal actions. Results of the remedy selection biodegradation assessment provided evidence of a 61 to 96 percent reduction in contaminant concentrations. These concentrations are below land disposal and health risk-based criteria. The technology of biodegradation meets the EPA criteria for inclusion in the potential remedies for the Macmillan Oil Refinery

  2. Biodegradation potential of photocatalyzed surfactant washwater.

    Science.gov (United States)

    Maillacheruvu, K; Buck, L; Lee, E

    2001-01-01

    Enhanced release of hydrophobic compounds from a soil matrix can be achieved by use of soil-washing or soil-flushing using various surfactants. However, the surfactants used in achieving the desorption of organic contaminants may also cause a problem in subsequent removal/disposal of these contaminants. UV radiation in the presence of TiO2 as a pre-treatment step to achieve initial (or partial) breakdown of naphthalene and Sodium Dodecyl Sulfate (SDS) using batch experiments indicated that 56% to 88% naphthalene degradation occurred within 30 minutes to one hour. Preliminary results on the estimate of the batch aerobic biodegradation potential of photocatalyzed washwater containing naphthalene and SDS suggested that SDS was the major carbon and energy source for an activated sludge enrichment culture and an enrichment culture obtained from microorganisms at a contaminated site. Continuous-flow stirred tank reactors (CSTRs) with with a solids retention time (SRT) of 4 days were not effective, but an SRT of 8 days was successful in biodegrading the naphthalene and surfactant. These results indicated that photocatalytic treatment as a pre-treatment step followed by a biodegradation step may offer potential in cleaning up surfactant washwaters containing organic contaminants. PMID:11501312

  3. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632, Pécs (Hungary); Scarpellini, A. [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Anjum, F.; Brandi, F. [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy)

    2013-05-01

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications.

  4. Biosynthesis of Enediyne Antitumor Antibiotics

    OpenAIRE

    Van Lanen, Steven G.; Shen, Ben

    2008-01-01

    The enediyne polyketides are secondary metabolites isolated from a variety of Actinomycetes. All members share very potent anticancer and antibiotic activity, and prospects for the clinical application of the enediynes has been validated with the recent marketing of two enediyne derivatives as anticancer agents. The biosynthesis of these compounds is of interest because of the numerous structural features that are unique to the enediyne family. The gene cluster for five enediynes has now been...

  5. Uncialamycin, a new enediyne antibiotic.

    Science.gov (United States)

    Davies, Julian; Wang, Hao; Taylor, Terry; Warabi, Kaoru; Huang, Xin-Hui; Andersen, Raymond J

    2005-11-10

    [structure: see text] Laboratory cultures of an undescribed streptomycete obtained from the surface of a British Columbia lichen produce uncialamycin (1), a new enediyne antibiotic. The structure of uncialamycin (1) has been elucidated by analysis of spectroscopic data. Uncialamycin (1) exhibits potent in vitro antibacterial activity against gram-positive and gram-negative human pathogens, including Burkholderia cepacia, a major cause of morbidity and mortality in patients with cystic fibrosis. PMID:16268546

  6. Minocycline: far beyond an antibiotic

    OpenAIRE

    Garrido-Mesa, N; Zarzuelo, A; Gálvez, J

    2013-01-01

    Minocycline is a second-generation, semi-synthetic tetracycline that has been in therapeutic use for over 30 years because of its antibiotic properties against both gram-positive and gram-negative bacteria. It is mainly used in the treatment of acne vulgaris and some sexually transmitted diseases. Recently, it has been reported that tetracyclines can exert a variety of biological actions that are independent of their anti-microbial activity, including anti-inflammatory and anti-apoptotic acti...

  7. Bacterial infections: antibiotics and decontamination.

    Science.gov (United States)

    Gould, Dinah

    Infectious disease is caused by bacteria, viruses, fungi, protozoa and micro-organisms including the mycoplasmas, rickettsiae and chlamydiae. Most of the infections commonly encountered in the UK are caused either by bacteria or viruses. This article describes bacterial structure and function to explain how antibiotics work and the processes of decontamination such as cleaning, disinfection and sterilisation, which are important in infection control. PMID:15224613

  8. Ocular delivery of macromolecules

    OpenAIRE

    Kim, Yoo-Chun; Chiang, Bryce; Wu, Xianggen; Prausnitz, Mark R.

    2014-01-01

    Biopharmaceuticals are making increasing impact on medicine, including treatment of indications in the eye. Macromolecular drugs are typically given by physician-administered invasive delivery methods, because non--invasive ocular delivery methods, such as eye drops, and systemic delivery, have low bioavailability and/or poor ocular targeting. There is a need to improve delivery of biopharmaceuticals to enable less-invasive delivery routes, less-frequent dosing through controlled-release drug...

  9. Pharmacological Drug Delivery Strategies for Improved Therapeutic Effects: Recent Advances.

    Science.gov (United States)

    Savaliya, Reema; Singh, Poornima; Singh, Sanjay

    2016-01-01

    The latest pharmacologic research has resulted number of new molecules with the potential to modernize the prevention or treatment of different complex diseases, including cancer. The therapeutics generally include moieties such as proteins, drugs and genes, etc. Current activities in the pharmacological field include the development of novel drug-delivery systems to overcome pharmacokinetic glitches such as limited bioavailability, unwanted distribution, drug resistant, and stability, etc. Therefore, to address these issues various biotechnological and pharmacological techniques has been introduced. However, effective drug delivery with improved efficacy remains challenging. This review is focused towards different strategies such as physical and biological methods for efficacious delivery at desired tissues and even sub-cellular targeting. Emphasis is also given about nanotechnology based drug or gene delivery strategies and co-delivery of drug-drug; gene-gene or combinations of drug-gene, etc. are the current cuttingedge methods, which are under clinical or pre-clinical stage of research. Uses of biodegradable materials, such as liposomes and polymeric particles are another class of drug delivery vehicles, which have shown tremendous success, are also discussed. Towards the end, future directions of pharmacological drug delivery methods have also been summarized. PMID:26654439

  10. Biodegradability evaluation of polymers by ISO 14855-2.

    Science.gov (United States)

    Funabashi, Masahiro; Ninomiya, Fumi; Kunioka, Masao

    2009-10-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradability were studied. Reproducibility of biodegradation test of ISO 14855-2 by MODA was confirmed. Validity of sample preparation method for polymer pellets, polymer film, and polymer products of ISO/DIS 10210 for ISO 14855-2 was confirmed. PMID:20111676

  11. Biodegradable materials as binders for IVth generation moulding sands

    Directory of Open Access Journals (Sweden)

    K. Major-Gabry

    2015-09-01

    Full Text Available This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the biodegradation rate of used binders, and the new biodegradable additive (PCL did not decrease the strength and thermal properties. In addition, using polycaprolactone (PCL as a biodegradable material may improve the flexibility of moulding sands with polymeric binder and reduce toxicity.

  12. Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Lee-Chun eSu

    2014-07-01

    Full Text Available Citrate-based polymers possess unique advantages for various biomedical applications since citric acid is a natural metabolism product, which is biocompatible and antimicrobial. In polymer synthesis, citric acid also provides multiple functional groups to control the crosslinking of polymers and active binding sites for further conjugation of biomolecules. Our group recently developed a number of citrate-based polymers for various biomedical applications by taking advantage of their controllable chemical, mechanical, and biological characteristics. In this study, various citric acid derived biodegradable polymers were synthesized and investigated for their physicochemical and antimicrobial properties. Results indicate that citric acid derived polymers reduced bacterial proliferation to different degrees based on their chemical composition. Among the studied polymers, poly(octamethylene citrate (POC showed approximately 70-80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers (CUPEs and biodegradable photoluminescent polymers (BPLPs also exhibited significant bacteria reduction of ~20% and ~50% for Staphylococcus aureus and Escherichia coli, respectively. Thus, the intrinsic antibacterial properties in citrate-based polymers enable them to inhibit bacteria growth without incorporation of antibiotics, silver nanoparticles, and other traditional bacteria-killing agents suggesting that they are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired.

  13. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    OpenAIRE

    José Maria Rodrigues da Luz; Sirlaine Albino Paes; Mateus Dias Nunes; Marliane de Cássia Soares da Silva; Maria Catarina Megumi Kasuya

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ul...

  14. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  15. Strawberry under low-tunnel protected with experimental biodegradable films

    International Nuclear Information System (INIS)

    A research was carried out in order to test innovative biodegradable materials for the protected cultivation of strawberry in Southern Italy. A field test was carried out in order to evaluate the agronomic performances of the biodegradable materials in comparison with non biodegradable LDPE materials. Different kinds of biodegradable black films were used for soil mulching and transparent biodegradable films for the covering of the low tunnels. Climatic data of the site, air temperature and relative humidity inside the low tunnels and soil temperature under the mulching films were gathered during the test. Besides, laboratory radiometric tests were executed on the films in order to evaluate parameters such as the transmissivity in different wavelength ranges. The biodegradable materials showed a high capacity to induce greenhouse effect due to their very low transmissivity in the long wave infrared range. The yield obtained using biodegradable materials was on average 12% higher then the one obtained with traditional films. Concerning the earliness, at the first day of the harvest, the yield obtained with biodegradable materials was 70% higher in comparison with the case of LDPE films. The research showed that the biodegradable materials could be a sustainable alternative to the plastic films based on fossil raw materials

  16. Influence of inorganic salt on aerobic biodegradability of dyestuffs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semicontinuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl =15 g/L; in the three NaCl conditions, biodegradability of tasted dyestuffs followed the following order: NaCl= 0 g/L > NaCl= 30g/L>NaCl= 15 g/L.

  17. Antibiotics as CECs: An Overview of the Hazards Posed by Antibiotics and Antibiotic Resistance

    OpenAIRE

    Geoffrey Ivan Scott; Porter, Dwayne E.; R. Sean Norman; C. Hart Scott; Miguel Ignacio Uyaguari-Diaz; Keith eMaruya; Steve B. Weisberg; Fulton, Michael H.; Ed F. Wirth; Janet eMooore; Pennington , Paul L.; Daniel eSchlenk; Cobb, George P.; Denslow, Nancy D.

    2016-01-01

    ABSTRACTMonitoring programs have traditionally monitored legacy contaminants but are shifting focus to Contaminants of Emerging Concern (CECs). CECs present many challenges for monitoring and assessment, because measurement methods don't always exist nor have toxicological studies been fully conducted to place results in proper context. Also some CECs affect metabolic pathways to produce adverse outcomes that are not assessed through traditional toxicological evaluations. Antibiotics are CEC...

  18. Electrospinning of Biodegradable and Biocompatible Nanofiber Patches from Solutions of ``Green'' Materials for Plant Protection against Fungi Attack

    Science.gov (United States)

    Sett, Soumyadip; Lee, Minwook; Yarin, Alexander; Moghadam, S. M. Alavi; Meinke, Matthias; Schroeder, Wolfgang

    2015-11-01

    Biodegradable and biocompatible soy protein/petroleum-derived polymer monolithic fibers containing adhesives were electrospun on commercial rayon pads. The polymers used, PVA and PCL, are widely used in the biomedical industry, including such applications as drug delivery and scaffold manufacturing. Soy protein is an abundant waste of SoyDiesel production, and is widely used as a nutrient. The soy content in our fibers was as high as 40% w/w. Four different adhesives, including ordinary wood glue, repositionable glue and FDA-approved pressure-sensitive glue were used for electrospinning and electrospraying. The normal and shear adhesive strengths of the patches developed in this work were measured and compared. The adhesive strength was sufficient enough to withstand normal atmospheric conditions. These biodegradable and biocompatible nano-textured patches are ready to be used on prune locations without being carried away by wind and will protect plants against fungi attack at these locations, preventing diseases like Vine Decline.

  19. Preventing neonatal group B streptococcal infection. Intrapartum antibiotic prophylaxis in some high-risk situations.

    Science.gov (United States)

    2011-03-01

    Group B streptococci (GBS) are the leading cause of life-threatening neonatal bacterial infections in developed countries. The newborn is initially colonised during passage through the birth canal. Maternal vaginal carriage is usually asymptomatic. How safe and effective are strategies aimed at preventing severe neonatal GBS infection? To answer these questions, we conducted a review of the literature using the standard Prescrire methodology. In France, Group B streptococci are present in the vagina of about 10-15% of women towards the end of pregnancy. Mother-to-child transmission can occur when the membranes rupture, or during delivery. About one-third of infants born to mothers who carry Group B streptococci are colonised at birth. GBS colonisation rarely affects the newborn's health but, during the first 7 days of life, about 3% of colonised children develop a serious early-onset infection, particularly meningitis, which may be fatal or leave sequelae. Late-onset infections (after 7 days of life) do not appear to be linked to intrapartum colonisation. The risk of early neonatal GBS infection increases in cases of preterm delivery, maternal fever during delivery, and membrane rupture more than 18 hours before delivery. These situations account for 50% to 75% of early neonatal GBS infections. Several randomised trials suggest that intravenous antibiotic prophylaxis in women who carry Group B streptococci, from the onset of labour until delivery, reduces the risk of early-onset neonatal GBS infection from 4.7% to 0.4% (p = 0.02). Other antibiotic strategies are less well assessed or appear to be less effective. Penicillin G (benzylpenicillin) is the antibiotic of choice, while penicillin A (ampicillin or amoxicillin) is an alternative. In case of penicillin allergy, erythromycin or clindamycin are generally active against Group B streptococci and carry no particular risks for the infant. The greatest risk associated with penicillin, especially injectable forms, is

  20. Mucoadhesive and muco-penetrating delivery systems for eradication of helicobacter pylori

    OpenAIRE

    Saahil Arora; Gaurav Bisen; R D Budhiraja

    2012-01-01

    Helicobacter pylori (H. pylori), the major culprit for peptic ulcer, has a unique way of survival in harsh acidic environment of the stomach by colonizing deep in the gastric mucosal layer. Failure of conventional therapies against H. pylori for complete eradication has major limitations like low residence time of delivery system in stomach, poor penetration of drug in gastric mucosa, acidic degradation of antibiotics, and development of antibiotics resistance. The poor penetration of antibio...

  1. RECENT ADVANCES IN NOVEL DRUG DELIVERY SYSTEMS

    Directory of Open Access Journals (Sweden)

    Manivannan Rangasamy

    2010-12-01

    Full Text Available Drug delivered can have significant effect on its efficacy. Some drugs have an optimum concentration range with in which maximum benefit is derived and concentrations above (or below the range can be toxic or produce no therapeutic effect. Various drug delivery and drug targeting systems are currently under development. The main goal for developing such delivery systems is to minimize drug degradation and loss, to prevent harmful side effects and to increase bioavailability. Targeting is the ability to direct the drug loaded system to the site of interest. Among drug carrier one can name soluble polymers, microparticles made of insoluble (or biodegradable natural and synthetic polymers, microcapsules, cells, cell ghosts, lipoproteins, liposomes and micelles. Two major mechanisms can be distinguished for addressing the desired sites for drug release, (a Passive and (b Active targeting. Controlled drug carrier systems such as micellar solutions, vescicles and liquid crystal dispersions, as well as nanoparticle dispersions consisting of small particles of 10 – 400 nm show great promise as drug delivery systems. Hydrogels are three dimensional, hydrophilic, polymer networks capable of imbibing large amounts of water or biological fluids. Buckyballs, a novel delivery system with 60 carbon atoms formed in the shape of hollow ball. They are other type’s namely bucky babies, fuzzy balls, gadofullereness, and giant fullerenes. Nanoparticles can be classified as nano tubes, nano wires, nano cantilever, nanoshells, quantum dots, nano pores. Researchers at north western university using gold particles to develop ultra sensitive detection systems for DNA and protein markers associated with many forms of cancer, including breast and prostrate cancer. Drug loaded erythrocytes is one of the growing and potential systems for delivery of drugs and enzymes.

  2. Genetically engineered nanocarriers for drug delivery

    Science.gov (United States)

    Shi, Pu; Gustafson, Joshua A; MacKay, J Andrew

    2014-01-01

    Cytotoxicity, low water solubility, rapid clearance from circulation, and off-target side-effects are common drawbacks of conventional small-molecule drugs. To overcome these shortcomings, many multifunctional nanocarriers have been proposed to enhance drug delivery. In concept, multifunctional nanoparticles might carry multiple agents, control release rate, biodegrade, and utilize target-mediated drug delivery; however, the design of these particles presents many challenges at the stage of pharmaceutical development. An emerging solution to improve control over these particles is to turn to genetic engineering. Genetically engineered nanocarriers are precisely controlled in size and structure and can provide specific control over sites for chemical attachment of drugs. Genetically engineered drug carriers that assemble nanostructures including nanoparticles and nanofibers can be polymeric or non-polymeric. This review summarizes the recent development of applications in drug and gene delivery utilizing nanostructures of polymeric genetically engineered drug carriers such as elastin-like polypeptides, silk-like polypeptides, and silk-elastin-like protein polymers, and non-polymeric genetically engineered drug carriers such as vault proteins and viral proteins. PMID:24741309

  3. Tailored Antibiotic Combination Powders for Inhaled Rotational Antibiotic Therapy.

    Science.gov (United States)

    Lee, Sie Huey; Teo, Jeanette; Heng, Desmond; Ng, Wai Kiong; Zhao, Yanli; Tan, Reginald B H

    2016-04-01

    Respiratory lung infections due to multidrug-resistant (MDR) superbugs are on a global upsurge and have very grim clinical outcomes. Their MDR profile makes therapeutic options extremely limited. Although a highly toxic antibiotic, colistin, is favored today as a "last-line" therapeutic against these hard-to-treat MDR pathogens, it is fast losing its effectiveness. This work therefore seeks to identify and tailor-make useful combination regimens (that are potentially rotatable and synergistic) as attractive alternative strategies to address the rising rates of drug resistance. Three potentially rotatable ternary dry powder inhaler constructs (each involving colistin and 2 other different-classed antibiotics chosen from rifampicin, meropenem, and tigecycline) were identified (with distinct complementary killing mechanisms), coformulated via spray drying, evaluated on their aerosol performance using a Next-Generation Impactor and tested for their efficacies against a number of MDR pathogens. The powder particles were of respirable size (d50, 3.1 ± 0.3 μm-3.4 ± 0.1 μm) and predominantly crumpled in morphology. When dispersed via a model dry powder inhaler (Aerolizer(®)) at 60 L/min, the powders showed concomitant in vitro deposition with fine particle fractions of ∼53%-70%. All formulations were successfully tested in the laboratory to be highly effective against the MDR pathogens. In addition, a favorable synergistic interaction was detected across all 3 formulations when tested against MDR Pseudomonas aeruginosa. PMID:27019964

  4. Polymer hydrogels as optimized delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Jorge G.S.; Varca, Gustavo H.C.; Ferraz, Caroline C.; Garrido, Gabriela P.; Diniz, Bruna M.; Carvalho, Vinicius S.; Lugao, Ademar B., E-mail: jorgegabriel@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Hydrogels are formed by polymers capable of absorbing large quantities of water. They consist of one or more three-dimensionally structured polymer networks formed by macromolecular chains linked by covalent bonds-crosslinks - and physical interactions. The application of hydrogels, has been widely studied. Biodegradable synthetic or natural polymers such as chitosan, starch and poly-lactic-co-glycolic acid, have properties that allow the development of biodegradable systems for drug and nutraceutics delivery. This study aimed to develop polymeric hydrogels based on polyvinyl alcohol, polyacrylamide and polyvinylpyrrolidone using ionizing radiation in order to develop hydrogels for improved loading and release of compounds. Polymer solutions were solubilized in water and poured into thermoformed packages. After sealing, the material was subjected to γ-irradiation at 25kGy. The samples were assayed by means of mechanical properties, gel fraction and swelling degree. Nanostructure characterization was performed using Flory's equation to determine crosslinking density. The systems developed showed swelling degree and adequate mechanical resistance. The nanostructure evaluation showed different results for each system demonstrating the need of choosing the polymer based on the specific properties of each material. (author)

  5. Response to "Antibiotic Use and Resistance"

    DEFF Research Database (Denmark)

    Malo, Sara; Rabanaque, María José; Feja, Christina; Lallana, María Jesús; Aguilar, Isabel; Bjerrum, Lars

    2014-01-01

    As mentioned, antibiotic consumption in heavy users, especially in children, is really striking. Certainly, our results revealed an antibiotic use in this age group higher than published in previous studies, and in line with different reports repeatedly presenting the high antibiotic consumption...... existing in Spain compared with other European countries (1). Determinants involved in antibiotic prescribing are numerous and varied. It is true that therapeutic failures lead to repeated courses of antibiotic treatment. However, it is not probably the only reason. Frequent and high consumption of...... antibiotics, as observed in heavy users, could also be due to factors related to the GP, patient and parents' expectations or the influence exerted by the pharmaceutical industry (2). This article is protected by copyright. All rights reserved....

  6. Factors Affecting the Cost Effectiveness of Antibiotics

    Directory of Open Access Journals (Sweden)

    Steven Simoens

    2011-01-01

    Full Text Available In an era of spiraling health care costs and limited resources, policy makers and health care payers are concerned about the cost effectiveness of antibiotics. The aim of this study is to draw on published economic evaluations with a view to identify and illustrate the factors affecting the cost effectiveness of antibiotic treatment of bacterial infections. The findings indicate that the cost effectiveness of antibiotics is influenced by factors relating to the characteristics and the use of antibiotics (i.e., diagnosis, comparative costs and comparative effectiveness, resistance, patient compliance with treatment, and treatment failure and by external factors (i.e., funding source, clinical pharmacy interventions, and guideline implementation interventions. Physicians need to take into account these factors when prescribing an antibiotic and assess whether a specific antibiotic treatment adds sufficient value to justify its costs.

  7. Sociobiology of biodegradation and the role of predatory protozoa in biodegrading communities

    Indian Academy of Sciences (India)

    Tejashree Modak; Shalmali Pradhan; Milind Watve

    2007-06-01

    Predatory protozoa are known to enhance biodegradation by bacteria in a variety of systems including rumen. This is apparently counterintuitive since many protozoa do not themselves produce extracellular degradative enzymes and prey upon bacterial degraders. We propose a mechanism of protozoal enhancement of bacterial biodegradation based on the sociobiology of biodegradation. Since extracellular enzyme production by degraders involves a cost to the bacterial cell, cheaters that do not make the enzyme will have a selective advantage. In the presence of cheaters, degraders that physically attach to water-insoluble substrate will have a selective advantage over free-floating degraders. On the other hand, cheaters will benefit by being free floaters since they consume the solubilized products of extracellular enzymes. Predatory ciliated protozoa are more likely to consume free-floating cheaters. Thus, due to protozoan predation a control is exerted on the cheater population. We illustrate the dynamics of such a system with the help of a computer simulation model. Available data on rumen and other biodegradation systems involving protozoa are compatible with the assumptions and predictions of the model.

  8. Biodegradable and semi-biodegradable composite hydrogels as bone substitutes: morphology and mechanical characterization.

    Science.gov (United States)

    Sanginario, V; Ginebra, M P; Tanner, K E; Planell, J A; Ambrosio, L

    2006-05-01

    Biodegradable and semi-biodegradable composite hydrogels are proposed as bone substitutes. They consist of an hydrophilic biodegradable polymer (HYAFF 11) as matrix and two ceramic powders (alpha-TCP and HA) as reinforcement. Both components of these composites have been of great interest in biomedical applications due to their excellent biocompatibility and tissue interactions, however they have never been investigated as bone substitute composites. Morphological and mechanical analysis have shown that the two fillers behave in a very different way. In the HYAFF 11/alpha-TCP composite, alpha-TCP is able to hydrolyze in contact with water while in the HYAFF 11 matrix. As a result, the composite sets and hardens, and entangled CDHA crystals are formed in the hydrogel phase and increases in the mechanical properties are obtained. In the HYAFF11/HA composite the ceramic reinforcement acts as inert phase leading to lower mechanical properties. Both mechanical properties and microstructure analysis have demonstrated the possibility to design hydrophilic biodegradable composite structures for bone tissue substitution applications. PMID:16688585

  9. Exogenous pulmonary surfactant as a drug delivering agent: influence of antibiotics on surfactant activity.

    OpenAIRE

    van 't Veen, A; Gommers, D.; Mouton, J. W.; Kluytmans, J.A.; Krijt, E. J.; Lachmann, B.

    1996-01-01

    1. It has been proposed to use exogenous pulmonary surfactant as a drug delivery system for antibiotics to the alveolar compartment of the lung. Little, however, is known about interactions between pulmonary surfactant and antimicrobial agents. This study investigated the activity of a bovine pulmonary surfactant after mixture with amphotericin B, amoxicillin, ceftazidime, pentamidine or tobramycin. 2. Surfactant (1 mg ml-1 in vitro and 40 mg ml-1 in vivo) was mixed with 0.375 mg ml-1 amphote...

  10. Naphthyridinomycin, a DNA-reactive antibiotic.

    OpenAIRE

    Zmijewski, M J; Miller-Hatch, K; Goebel, M.

    1982-01-01

    Naphthyridinomycin is a novel quinone antibiotic that is produced in liquid shake cultures by Streptomyces lusitanus. Fermentation studies have shown that this antibiotic is produced maximally after 96 h of cell growth. L-[methyl-3H]methionine efficiently labels naphthyridinomycin when it is added to a fermentation mixture 24 h before culture is harvested. Unlabeled and radioactively labeled naphthyridinomycin were used to determine the mechanism of action of this unique antibiotic. Naphthyri...

  11. Antibiotics for the Treatment of Hepatic Encephalopathy

    OpenAIRE

    Patidar, Kavish R.; Bajaj, Jasmohan S.

    2013-01-01

    The treatment of hepatic encephalopathy (HE) is complex and therapeutic regimens vary according to the acuity of presentation and the goals of therapy. Most treatments for HE rely on manipulating the intestinal milieu and therefore antibiotics that act on the gut form a key treatment strategy. Prominent antibiotics studied in HE are neomycin, metronidazole, vancomycin and rifaximin. For the management of the acute episode, all antibiotics have been tested. However the limited numbers studied,...

  12. DETECTION OF ANTIBIOTIC RESIDUES IN RAW MILK

    Directory of Open Access Journals (Sweden)

    G. Karim

    1978-06-01

    Full Text Available Milk and milk products containing antibiotics especially penicillin may present a health hazard to individuals who are super sensitized to penicillin. A total of 620 samples of raw milk which were delivered to Tehran pasteurization plant were examined. 294 samples were antibiotic-negative and 326 samples showed to contain antibiotic. Considering the results obtained, certain recommendations were made to prevent public health hazards and economic losses.

  13. Superbugs and antibiotics in the newborn

    OpenAIRE

    Alessandro Borghesi; Mauro Stronati

    2015-01-01

    Antibiotic resistance has become an urgent and global issue, with 700,000 deaths attributable to multidrug-resistance occurring each year worldwide. The overuse of antibiotics, both in animal industry and in clinical settings, and the generated selective pressure, are the main factors implicated in the emergence of resistant strains. The Centers for Disease Control and Prevention (CDC) have pointed out that more than half of hospital patients receive an antibiotic during their stay, and nearl...

  14. Antibiotic Resistance in Childhood with Pneumococcal Infection

    OpenAIRE

    Ali Gunes

    2013-01-01

    Aim: Resistance to antibiotics is better. Between should not be in capitals. Antibiotics resistant has been increasing in pneumococci that cause serious diseases such as pneumonia, meningitis in recent years. The resistance rates vary between geographic regions. In this study, we aimed to determine antibiotic resistance rates in pneumococcal infections in our region. Material and Method: This study included 31 pneumococcal strains isolated from blood, CSF and urine samples of patients with me...

  15. Getting into the brain: approaches to enhance brain drug delivery.

    Science.gov (United States)

    Patel, Mayur M; Goyal, Bhoomika R; Bhadada, Shraddha V; Bhatt, Jay S; Amin, Avani F

    2009-01-01

    .g. liposomes, microspheres, nanoparticles, nanogels and bionanocapsules) have been used to enhance drug delivery to the brain. Recently, microchips and biodegradable polymers have become important in brain tumour therapy.The intense search for alternative routes of drug delivery (e.g. intranasal drug delivery, convection-enhanced diffusion and intrathecal/intraventricular drug delivery systems) has been driven by the need to overcome the physiological barriers of the brain and to achieve high drug concentrations within the brain. For more than 30 years, considerable efforts have been made to enhance the delivery of therapeutic molecules across the vascular barriers of the CNS. The current challenge is to develop drug delivery strategies that will allow the passage of drug molecules through the BBB in a safe and effective manner. PMID:19062774

  16. Treatment of critically sized femoral defects with recombinant BMP-2 delivered by a modified mPEG-PLGA biodegradable thermosensitive hydrogel

    OpenAIRE

    Peng, Kuo-Ti; Hsieh, Meng-Yow; Lin, Carl T.; Chen, Chin-Fu; Lee, Mel S.; Huang, Yi-You; CHANG, PEY-JIUM

    2016-01-01

    Background Reconstruction of a segmental fracture with massive bone loss is still a challenge for orthopaedic surgeons. The aim of our study was to develop a suitable biodegradable thermosensitive hydrogel system as a carrier for bone morphogenetic protein (BMP)-2 delivery in the treatment of critical-sized femoral defects. Methods A block copolymer composed of monomethoxypoly(ethylene glycol) (mPEG), poly(lactic-co-glycolic acid) (PLGA) and 2, 2’-Bis (2-oxazolin) (Box) was synthesized by rin...

  17. In vitro perforation of human epithelial carcinoma cell with antibody-conjugated biodegradable microspheres illuminated by a single 80 femtosecond near-infrared laser pulse

    OpenAIRE

    Terakawa M; Tsunoi Y; Mitsuhashi T

    2012-01-01

    Mitsuhiro Terakawa, Yasuyuki Tsunoi, Tatsuki MitsuhashiDepartment of Electronics and Electrical Engineering, Keio University, Yokohama, Kanagawa, JapanAbstract: Pulsed laser interaction with small metallic and dielectric particles has been receiving attention as a method of drug delivery to many cells. However, most of the particles are attended by many risks, which are mainly dependent upon particle size. Unlike other widely used particles, biodegradable particles have advantages of being br...

  18. eDelivery

    Data.gov (United States)

    US Agency for International Development — eDelivery provides the electronic packaging and delivery of closed and complete OPM investigation files to government agencies, including USAID, in a secure manner....

  19. Antibiotic research and development: business as usual?

    Science.gov (United States)

    Harbarth, S; Theuretzbacher, U; Hackett, J

    2015-01-01

    The global burden of antibiotic resistance is tremendous and, without new anti-infective strategies, will continue to increase in the coming decades. Despite the growing need for new antibiotics, few pharmaceutical companies today retain active antibacterial drug discovery programmes. One reason is that it is scientifically challenging to discover new antibiotics that are active against the antibiotic-resistant bacteria of current clinical concern. However, the main hurdle is diminishing economic incentives. Increased global calls to minimize the overuse of antibiotics, the cost of meeting regulatory requirements and the low prices of currently marketed antibiotics are strong deterrents to antibacterial drug development programmes. New economic models that create incentives for the discovery of new antibiotics and yet reconcile these incentives with responsible antibiotic use are long overdue. DRIVE-AB is a €9.4 million public-private consortium, funded by the EU Innovative Medicines Initiative, that aims to define a standard for the responsible use of antibiotics and to develop, test and recommend new economic models to incentivize investment in producing new anti-infective agents. PMID:25673635

  20. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by pot experiment and It was promising to prevent pepper, Chinese cabbage and radish from anthrax, phytophthora and root rot

  1. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Sixteen antifungal microbes were isolated and 4 antifungal activity enhanced mutants were induced by using radiation. P. lentimorbus WJ5a17 had 41% higher antifungal activity than the wild type. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified

  2. Lipase biocatalysis for useful biodegradable products

    Energy Technology Data Exchange (ETDEWEB)

    Linko, Y.Y.; Wang, Zhuo Lin; Uosukainen, E.; Seppaelae, J. [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M. [Raisio Group Oil Milling Industry, Raisio (Finland)

    1996-12-31

    It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

  3. Development of biodegradable fungicide by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngkeun; Kim, Dongsub

    2012-03-15

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by field test and it was promising to prevent Chinese cabbage and radish from phytophthora and root rot.

  4. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  5. Hydrocarbons biodegradation in unsaturated porous medium; Biodegradation des hydrocarbures en milieu poreux insature

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, C

    2007-12-15

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  6. Dendrimeric Systems and Their Applications in Ocular Drug Delivery

    Directory of Open Access Journals (Sweden)

    Burçin Yavuz

    2013-01-01

    Full Text Available Ophthalmic drug delivery is one of the most attractive and challenging research area for pharmaceutical scientists and ophthalmologists. Absorption of an ophthalmic drug in conventional dosage forms is seriously limited by physiological conditions. The use of nonionic or ionic biodegradable polymers in aqueous solutions and colloidal dosage forms such as liposomes, nanoparticles, nanocapsules, microspheres, microcapsules, microemulsions, and dendrimers has been studied to overcome the problems mentioned above. Dendrimers are a new class of polymeric materials. The unique nanostructured architecture of dendrimers has been studied to examine their role in delivery of therapeutics and imaging agents. Dendrimers can enhance drug’s water solubility, bioavailability, and biocompatibility and can be applied for different routes of drug administration successfully. Permeability enhancer properties of dendrimers were also reported. The use of dendrimers can also reduce toxicity versus activity and following an appropriate application route they allow the delivery of the drug to the targeted site and provide desired pharmacokinetic parameters. Therefore, dendrimeric drug delivery systems are of interest in ocular drug delivery. In this review, the limitations related to eye’s unique structure, the advantages of dendrimers, and the potential applications of dendrimeric systems to ophthalmology including imaging, drug, peptide, and gene delivery will be discussed.

  7. Dendrimeric systems and their applications in ocular drug delivery.

    Science.gov (United States)

    Yavuz, Burçin; Pehlivan, Sibel Bozdağ; Unlü, Nurşen

    2013-01-01

    Ophthalmic drug delivery is one of the most attractive and challenging research area for pharmaceutical scientists and ophthalmologists. Absorption of an ophthalmic drug in conventional dosage forms is seriously limited by physiological conditions. The use of nonionic or ionic biodegradable polymers in aqueous solutions and colloidal dosage forms such as liposomes, nanoparticles, nanocapsules, microspheres, microcapsules, microemulsions, and dendrimers has been studied to overcome the problems mentioned above. Dendrimers are a new class of polymeric materials. The unique nanostructured architecture of dendrimers has been studied to examine their role in delivery of therapeutics and imaging agents. Dendrimers can enhance drug's water solubility, bioavailability, and biocompatibility and can be applied for different routes of drug administration successfully. Permeability enhancer properties of dendrimers were also reported. The use of dendrimers can also reduce toxicity versus activity and following an appropriate application route they allow the delivery of the drug to the targeted site and provide desired pharmacokinetic parameters. Therefore, dendrimeric drug delivery systems are of interest in ocular drug delivery. In this review, the limitations related to eye's unique structure, the advantages of dendrimers, and the potential applications of dendrimeric systems to ophthalmology including imaging, drug, peptide, and gene delivery will be discussed. PMID:24396306

  8. pHEMA hydrogels: Devices for ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Neha Tomar

    2012-01-01

    Full Text Available Drug delivery to eye has become a demanding task because of various constraints of eye i.e., physiological and anatomical, which results in improper therapeutic concentration at the site of action. Due to this problem, frequent dosing was recommended causing patient incompliance and adding to the cost of therapy. To overcome these barriers, researchers have discovered novel ocular delivery systems like hydrogels, ocuserts, colloidal carriers, etc. However, every delivery system has its own advantages and disadvantages. Hydrogels are presently utilized as delivery system for actives because of their comparable physical properties to that of living tissue. A plethora of biodegradable polymers are used for hydrogel formulations like polyanhydrides, poly (orthoesters, polyesters and poly (2-hydroxyethyl methacrylate (pHEMA, chitosan and sodium alginate out of which pHEMA hydrogels are becoming popular from a therapeutic point of view for the ocular drug delivery. The present paper broadly describes the recent advances on drug delivery using pHEMA hydrogels with exhaustive details of researches explored till date.

  9. NEW DRUG DELIVERY SYSTEM

    OpenAIRE

    Sarkar Biresh K; Jain Devananda; Banerjee Angshu

    2011-01-01

    Incorporating an existing medicine into a new drug delivery system can significantly improve its performance in terms of efficacy, safety, and improved patient compliance. The need for delivering drugs to patients efficiently and with fewer side effects has prompted pharmaceutical companies to engage in the development of new drug delivery systems. Today, drug delivery companies are engaged in the development of multiple platform technologies for controlled release, delivery of large molecule...

  10. Biodegradation of clofibric acid and identification of its metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, R. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); ESTS-IPS, Escola Superior de Tecnologia de Setubal do Instituto Politecnico de Setubal, Rua Vale de Chaves, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); Oehmen, A. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Carvalho, G. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Instituto de Biologia Experimental e Tecnologica (IBET), Av. da Republica (EAN), 2784-505 Oeiras (Portugal); Noronha, J.P. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Reis, M.A.M., E-mail: amr@fct.unl.pt [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2012-11-30

    Graphical abstract: Metabolites produced during clofibric acid biodegradation. Highlights: Black-Right-Pointing-Pointer Clofibric acid is biodegradable. Black-Right-Pointing-Pointer Mainly heterotrophic bacteria degraded the clofibric acid. Black-Right-Pointing-Pointer Metabolites of clofibric acid biodegradation were identified. Black-Right-Pointing-Pointer The metabolic pathway of clofibric acid biodegradation is proposed. - Abstract: Clofibric acid (CLF) is the pharmaceutically active metabolite of lipid regulators clofibrate, etofibrate and etofyllinclofibrate, and it is considered both environmentally persistent and refractory. This work studied the biotransformation of CLF in aerobic sequencing batch reactors (SBRs) with mixed microbial cultures, monitoring the efficiency of biotransformation of CLF and the production of metabolites. The maximum removal achieved was 51% biodegradation (initial CLF concentration = 2 mg L{sup -1}), where adsorption and abiotic removal mechanisms were shown to be negligible, showing that CLF is indeed biodegradable. Tests showed that the observed CLF biodegradation was mainly carried out by heterotrophic bacteria. Three main metabolites were identified, including {alpha}-hydroxyisobutyric acid, lactic acid and 4-chlorophenol. The latter is known to exhibit higher toxicity than the parent compound, but it did not accumulate in the SBRs. {alpha}-Hydroxyisobutyric acid and lactic acid accumulated for a period, where nitrite accumulation may have been responsible for inhibiting their degradation. A metabolic pathway for the biodegradation of CLF is proposed in this study.

  11. The use of biodegradable mulch films in muskmelon crop production

    Directory of Open Access Journals (Sweden)

    Artur Saraiva

    2012-10-01

    Full Text Available Due to the large amount of mulch films used in agricultural crops and to all the environmental problems related with their disposal, the biodegradable mulch films seems to be the best solution for replacing the conventional polyethylene mulches. The main goal of this work was to evaluate and compare the performance of biodegradable mulch films with the conventional polyethylene ones in muskmelon culture during two years. Beyond fruit productivity and quality, the impact of each plastic in the soil moisture and temperature were also assessed. Taking into account that there are no reported biodegradation studies realized in Portugal, it was also important to verify the biodegradability of this new mulch films under the Portuguese soil conditions. The biodegradable mulch films did not show significant differences in fruit productivity and quality. The biodegradation rate of the mulches tested was not as high as would be expected. From the overall results obtained, biodegradable mulch films appear to be a good solution for the replacement of the conventional polyethylene mulches, however the Research and Development should continue to be done ton improve their biodegradation rate.

  12. Biodegradable elastomers for biomedical applications and regenerative medicine

    NARCIS (Netherlands)

    Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W.; Poot, Andre A.

    2014-01-01

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

  13. Deliberations on the impact of antibiotic contamination on dissemination of antibiotic resistance genes in aquatic environments

    OpenAIRE

    Berglund, Björn

    2014-01-01

    The great success of antibiotics in treating bacterial infectious diseases has been hampered by the increasing prevalence of antibiotic resistant bacteria. Not only does antibiotic resistance threaten to increase the difficulty in treating bacterial infectious diseases, but it could also make medical procedures such as routine surgery and organ transplantations very dangerous to perform. Traditionally, antibiotic resistance has been regarded as a strictly clinical problem and studies of the p...

  14. Antibiotic Resistance in Wastewater : Methicillin-resistant Staphylococcus aureus (MRSA)and antibiotic resistance genes

    OpenAIRE

    Börjesson, Stefan

    2009-01-01

    A large part of the antibiotics consumed ends up in wastewater, and in the wastewater the antibiotics may exert selective pressure for or maintain resistance among microorganisms. Antibiotic resistant bacteria and genes encoding antibiotic resistance are commonly detected in wastewater, often at higher rates and concentrations compared to surface water. Wastewater can also provide favourable conditions for the growth of a diverse bacterial community, which constitutes a basis for the selectio...

  15. [Health economics and antibiotic therapy].

    Science.gov (United States)

    Leclercq, P; Bigdéli, M

    1995-01-01

    In the field of antibiotic therapy, particularly the methods of economic evaluation hold one's attention within the wide range of health economics' applications. Several tools allow a comparison of the outcomes of alternative strategies and thereby guide choices to the most appropriate solutions. After a brief recall of the methods classically used to evaluate health care strategy, the authors stress the importance and difficulty of fixing and applying a correct and satisfactory procedure for evaluation. An evaluation example of antibiotic therapy allows to illustrate the application of the principles confronting a field in which competition is intense and economic stakes stay large--a fact which naturally yields to seek after objective decision making criteria. The health care policies drawn by public authorities as well as the marketing strategies of the health sector trade are partly based on such evaluations. If these techniques are not intended for the practitioner in the first place, they should not be indifferent to him since they influence health authorities and thereby indirectly affect the therapeutic freedom of the physician. PMID:7481251

  16. Molecular modelling of betalactamic antibiotic

    Directory of Open Access Journals (Sweden)

    Elso Manuel Cruz Cruz

    2010-02-01

    Full Text Available Background: The antibacterial properties of a compound are the result of its molecular structure. To establish the structural and electronic characteristics makes possible to understand the mechanisms of its action and becomes paramount for the rational design new drugs. Objective: To model some of the molecular properties of betalactamic antibiotics and inhibitors of the betalactamases and to relate them with their pharmacological actions. Method: The molecular structures were optimized with PM3• semiempiric calculus. The structure of the betalactamic ring in the different compounds was compared. The molecular properties were calculated according to the Density Functional Theory at a B3LYP/6-31G(d level. The density of the atomic charges and the frontier orbitals were analyzed. Results There are variations in the calculated properties that make possible to define two groups of compounds: one for the monobactams and the inhibitors of the betalactamases, with less planarity in the ring and less reactivity and another one with the penicillins, cephalosporins and carbapenems, planer, more structurally stable and reactive. Conclusions: The modelled molecular properties of the betalactamic antibiotics and inhibitors of the betalactamases show agreement with its pharmacological action.

  17. Gums' based delivery systems: Review on cashew gum and its derivatives.

    Science.gov (United States)

    Ribeiro, António J; de Souza, Flávia R Lucena; Bezerra, Janira M N A; Oliveira, Claudia; Nadvorny, Daniela; de La Roca Soares, Monica F; Nunes, Lívio C C; Silva-Filho, Edson C; Veiga, Francisco; Soares Sobrinho, José L

    2016-08-20

    The development of delivery systems using natural polymers such as gums offers distinct advantages, such as, biocompatibility, biodegradability, and cost effectiveness. Cashew gum (CG) has rheological and mucoadhesive properties that can find many applications, among which the design of delivery systems for drugs and other actives such as larvicide compounds. In this review CG is characterized from its source through to the process of purification and chemical modification highlighting its physicochemical properties and discussing its potential either for micro and nanoparticulate delivery systems. Chemical modifications of CG increase its reactivity towards the design of delivery systems, which provide a sustained release effect for larvicide compounds. The purification and, the consequent characterization of CG either original or modified are of utmost importance and is still a continuing challenge when selecting the suitable CG derivative for the delivery of larvicide compounds. PMID:27178924

  18. Natural history of the infant gut microbiome and impact of antibiotic treatment on bacterial strain diversity and stability.

    Science.gov (United States)

    Yassour, Moran; Vatanen, Tommi; Siljander, Heli; Hämäläinen, Anu-Maaria; Härkönen, Taina; Ryhänen, Samppa J; Franzosa, Eric A; Vlamakis, Hera; Huttenhower, Curtis; Gevers, Dirk; Lander, Eric S; Knip, Mikael; Xavier, Ramnik J

    2016-06-15

    The gut microbial community is dynamic during the first 3 years of life, before stabilizing to an adult-like state. However, little is known about the impact of environmental factors on the developing human gut microbiome. We report a longitudinal study of the gut microbiome based on DNA sequence analysis of monthly stool samples and clinical information from 39 children, about half of whom received multiple courses of antibiotics during the first 3 years of life. Whereas the gut microbiome of most children born by vaginal delivery was dominated by Bacteroides species, the four children born by cesarean section and about 20% of vaginally born children lacked Bacteroides in the first 6 to 18 months of life. Longitudinal sampling, coupled with whole-genome shotgun sequencing, allowed detection of strain-level variation as well as the abundance of antibiotic resistance genes. The microbiota of antibiotic-treated children was less diverse in terms of both bacterial species and strains, with some species often dominated by single strains. In addition, we observed short-term composition changes between consecutive samples from children treated with antibiotics. Antibiotic resistance genes carried on microbial chromosomes showed a peak in abundance after antibiotic treatment followed by a sharp decline, whereas some genes carried on mobile elements persisted longer after antibiotic therapy ended. Our results highlight the value of high-density longitudinal sampling studies with high-resolution strain profiling for studying the establishment and response to perturbation of the infant gut microbiome. PMID:27306663

  19. Mesostructured silica and aluminosilicate carriers for oxytetracycline delivery systems.

    Science.gov (United States)

    Berger, D; Nastase, S; Mitran, R A; Petrescu, M; Vasile, E; Matei, C; Negreanu-Pirjol, T

    2016-08-30

    Oxytetracycline delivery systems containing various MCM-type silica and aluminosilicate with different antibiotic content were developed in order to establish the influence of the support structural and textural properties and aluminum content on the drug release profile. The antibiotic molecules were loaded into the support mesochannels by incipient wetness impregnation method using a drug concentrated aqueous solution. The carriers and drug-loaded materials were investigated by small- and wide-angle XRD, FTIR spectroscopy, TEM and N2 adsorption-desorption isotherms. Faster release kinetics of oxytetracycline from uncalcined silica and aluminosilicate supports was observed, whereas higher drug content led to lower delivery rate. The presence of aluminum into the silica network also slowed down the release rate. The antimicrobial assays performed on Staphylococcus aureus clinical isolates showed that the oxytetracycline-loaded materials containing MCM-41-type mesoporous silica or aluminosilicate carriers inhibited the bacterial development. PMID:26861688

  20. WATER SOLUBLE MAGNETITE NANOPARTICLES FOR ANTIMICROBIAL DRUGS DELIVERY

    Directory of Open Access Journals (Sweden)

    Dan Eduard Mihaiescu

    2012-06-01

    Full Text Available Water-soluble magnetite has been prepared through precipitation approach. These nanoparticles coated with sulfanilic acid could be dispersed in hydrated aqueous systems. The product was characterized with X-ray powder diffraction (XRD, Dynamic Light Scattering (DLS and the in vitro efficacy as antibiotic delivery vehicles as well as their influence on the eukariotic cells. The XRD pattern confirm the product to be Fe3O4. The nanoparticles with average size 10.45 nanometers are not cytotoxic and do not influence the eukariotic HeLa cell cycle, representing potential tools for the delivery of drugs in a safe manner. Water soluble magnetite improves the activity of currently used antibiotics, representing potential as a nanocarrier for these antimicrobial substances, to achieve extracellular and intracellular targets.

  1. Ecotoxicological potential of antibiotic pollution-industrial wastewater: bioavailability, biomarkers, and occurrence in Mytilus galloprovincialis.

    Science.gov (United States)

    Zouiten, Amina; Beltifa, Asma; Van Loco, Joris; Mansour, Hedi Ben; Reyns, Tim

    2016-08-01

    Environmental pollution by pharmaceutical residues has become a major problem in many countries worldwide. However, little is known about the concentrations of pharmaceuticals in water sources in Tunisia. Residues in the natural environment have been of increasing concern due to their impact on bacteria resistance development and toxicity to natural communities and ultimately to public health. In this work, we collected the wastewater sample from a pharmaceutical industry, which specializes in the antibiotics manufacture, during the years 2014-2015. Generally, this effluent is discharged into the marine environment and causes environmental problems. The Mediterranean mussel Mytilus galloprovincialis was commonly used as a model organism for its peculiar morphofunctional properties which also make it an excellent marine environmental biomonitoring species. The histological sections of mussel, which are exposed at different dilutions of pharmaceutical wastewater (PW), indicate a large pathological power revealed on the gills. On the other hand, genotoxicity of the studied effluent was evaluated using comet assay for quantification of DNA fragmentation in gill cells. Results show that PW exhibited a statistically significant (p toxic effects of PW decreased significantly after its treatment with Bacillus atrophaeus. Toxicities can be imputed to the presence of antibiotics. In fact, chemical analysis of the gills of mussel M. galloprovincialis using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) showed the presence of some antibiotic residues. These concentrations decrease to half in mussels treated with PW biodegraded by B. atrophaeus. PMID:27109112

  2. Whey protein concentrate doped electrospun poly(epsilon-caprolactone) fibers for antibiotic release improvement.

    Science.gov (United States)

    Ahmed, Said Mahmoud; Ahmed, Hanaa; Tian, Chang; Tu, Qin; Guo, Yadan; Wang, Jinyi

    2016-07-01

    Design and fabrication of scaffolds using appropriate biomaterials are a key step for the creation of functionally engineered tissues and their clinical applications. Poly(epsilon-caprolactone) (PCL), a biodegradable and biocompatible material with negligible cytotoxicity, is widely used to fabricate nanofiber scaffolds by electrospinning for the applications of pharmaceutical products and wound dressings. However, the use of PCL as such in tissue engineering is limited due to its poor bioregulatory activity, high hydrophobicity, lack of functional groups and neutral charge. With the attempt to found nanofiber scaffolds with antibacterial activity for skin tissue engineering, in this study, whey protein concentrate (WPC) was used to modify the PCL nanofibers by doping it in the PCL electrospun solution. By adding proteins into PCL nanofibers, the degradability of the fibers may be increased, and this further allows an antibiotic incorporated in the fibers to be efficiently released. The morphology, wettability and degradation of the as-prepared PCL/WPC nanofibers were carefully characterized. The results showed that the PCL/WPC nanofibers possessed good morphology and wettability, as well as high degradation ability to compare with the pristine PCL fibers. Afterwords, tetracycline hydrochloride as a model antibiotic drug was doped in the PCL/WPC nanofibers. In vitro drug release assays demonstrated that PCL/WPC nanofibers had higher antibiotic release capability than the PCL nanofibers. Also, antibacterial activity evaluation against various bacteria showed that the drug-doped PCL/WPC fibers possessed more efficient antibacterial activity than the PCL nanofibers. PMID:27022878

  3. Silver nanoparticle-embedded polymersome nanocarriers for the treatment of antibiotic-resistant infections

    Science.gov (United States)

    Geilich, Benjamin M.; van de Ven, Anne L.; Singleton, Gloria L.; Sepúlveda, Liuda J.; Sridhar, Srinivas; Webster, Thomas J.

    2015-02-01

    The rapidly diminishing number of effective antibiotics that can be used to treat infectious diseases and associated complications in a physician's arsenal is having a drastic impact on human health today. This study explored the development and optimization of a polymersome nanocarrier formed from a biodegradable diblock copolymer to overcome bacterial antibiotic resistance. Here, polymersomes were synthesized containing silver nanoparticles embedded in the hydrophobic compartment, and ampicillin in the hydrophilic compartment. Results showed for the first time that these silver nanoparticle-embedded polymersomes (AgPs) inhibited the growth of Escherichia coli transformed with a gene for ampicillin resistance (bla) in a dose-dependent fashion. Free ampicillin, AgPs without ampicillin, and ampicillin polymersomes without silver nanoparticles had no effect on bacterial growth. The relationship between the silver nanoparticles and ampicillin was determined to be synergistic and produced complete growth inhibition at a silver-to-ampicillin ratio of 1 : 0.64. In this manner, this study introduces a novel nanomaterial that can effectively treat problematic, antibiotic-resistant infections in an improved capacity which should be further examined for a wide range of medical applications.

  4. Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction

    Directory of Open Access Journals (Sweden)

    Aleksandar Sabljic

    2004-12-01

    Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  5. Experimental studies of biodegradation of asphalt by microorganisms

    International Nuclear Information System (INIS)

    On the geological disposal system of the radioactive wastes, the activities of the microorganisms that could degrade the asphalt might be significant for the assessment of the system performance. As the main effects of the biodegradation of the asphalt, the fluctuation of leaching behavior of the nuclides included in asphalt waste has been indicated. In this study, the asphalt biodegradation test was carried out. The microorganism of which asphalt degradation ability was comparatively higher under aerobic condition and anaerobic condition was used. The asphalt biodegradation rate was calculated and it was evaluated whether the asphalt biodegradation in this system could occur. The results show that the asphalt biodegradation rate under anaerobic and high alkali condition will be 300 times lower than under aerobic and neutral pH. (author)

  6. Superbugs and antibiotics in the newborn

    Directory of Open Access Journals (Sweden)

    Alessandro Borghesi

    2015-10-01

    Full Text Available Antibiotic resistance has become an urgent and global issue, with 700,000 deaths attributable to multidrug-resistance occurring each year worldwide. The overuse of antibiotics, both in animal industry and in clinical settings, and the generated selective pressure, are the main factors implicated in the emergence of resistant strains. The Centers for Disease Control and Prevention (CDC have pointed out that more than half of hospital patients receive an antibiotic during their stay, and nearly a third receive a broad-spectrum antibiotic. In neonatal units, previous antibiotic exposure to third-generation cephalosporin and carbapenem were identified as independent risk factors for infection caused by multi-drug resistant strains. While resistant ‘superbugs’ emerge, the arsenal to fight these microorganisms is progressively shrinking, as the number of newly discovered antibiotics approved by the Food and Drug administration each year is dropping. In face of global spread of antibiotic resistance and of the limited development of new drugs, policies and rules are under study by agencies (CDC, World Health Organization and governments, in order to: i facilitate and foster the discovery of new antibiotic compounds; ii develop new, alternative therapies able to potentiate or modulate the host immune response or to abrogate the resistance and virulence factors in the microorganisms; and iii prevent the emergence of resistance through antibiotic stewardship programs, educational programs, and reduction of antibiotic use in livestock; the field of neonatal medicine will need its own, newborn-tailored, antibiotic stewardship programs to be implemented in the NICUs. Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy · October 26th-31st, 2015 · From the womb to the adultGuest Editors: Vassilios Fanos (Cagliari, Italy, Michele Mussap (Genoa, Italy, Antonio Del Vecchio (Bari, Italy, Bo Sun (Shanghai

  7. Optimizing antibiotic selection in treating COPD exacerbations

    Directory of Open Access Journals (Sweden)

    Attiya Siddiqi

    2008-03-01

    Full Text Available Attiya Siddiqi, Sanjay SethiDivision of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Veterans Affairs Western New York Health Care System and University of Buffalo, State University of New York, Buffalo, New York, USAAbstract: Our understanding of the etiology, pathogenesis and consequences of acute exacerbations of chronic obstructive pulmonary disease (COPD has increased substantially in the last decade. Several new lines of evidence demonstrate that bacterial isolation from sputum during acute exacerbation in many instances reflects a cause-effect relationship. Placebo-controlled antibiotic trials in exacerbations of COPD demonstrate significant clinical benefits of antibiotic treatment in moderate and severe episodes. However, in the multitude of antibiotic comparison trials, the choice of antibiotics does not appear to affect the clinical outcome, which can be explained by several methodological limitations of these trials. Recently, comparison trials with nontraditional end-points have shown differences among antibiotics in the treatment of exacerbations of COPD. Observational studies that have examined clinical outcome of exacerbations have repeatedly demonstrated certain clinical characteristics to be associated with treatment failure or early relapse. Optimal antibiotic selection for exacerbations has therefore incorporated quantifying the risk for a poor outcome of the exacerbation and choosing antibiotics differently for low risk and high risk patients, reserving the broader spectrum drugs for the high risk patients. Though improved outcomes in exacerbations with antibiotic choice based on such risk stratification has not yet been demonstrated in prospective controlled trials, this approach takes into account concerns of disease heterogeneity, antibiotic resistance and judicious antibiotic use in exacerbations.Keywords: COPD, exacerbation, bronchitis, antibiotics

  8. Membrane-Active Macromolecules Resensitize NDM-1 Gram-Negative Clinical Isolates to Tetracycline Antibiotics

    Science.gov (United States)

    Uppu, Divakara S. S. M.; Manjunath, Goutham B.; Yarlagadda, Venkateswarlu; Kaviyil, Jyothi E.; Ravikumar, Raju; Paramanandham, Krishnamoorthy; Shome, Bibek R.; Haldar, Jayanta

    2015-01-01

    Gram-negative ‘superbugs’ such as New Delhi metallo-beta-lactamase-1 (blaNDM-1) producing pathogens have become world’s major public health threats. Development of molecular strategies that can rehabilitate the ‘old antibiotics’ and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMs) that restore the antibacterial efficacy (enhancement by >80-1250 fold) of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates. Organismic studies showed that bacteria had an increased and faster uptake of tetracycline in the presence of MAMs which is attributed to the mechanism of re-sensitization. Moreover, bacteria did not develop resistance to MAMs and MAMs stalled the development of bacterial resistance to tetracycline. MAMs displayed membrane-active properties such as dissipation of membrane potential and membrane-permeabilization that enabled higher uptake of tetracycline in bacteria. In-vivo toxicity studies displayed good safety profiles and preliminary in-vivo antibacterial efficacy studies showed that mice treated with MAMs in combination with antibiotics had significantly decreased bacterial burden compared to the untreated mice. This report of re-instating the efficacy of the antibiotics towards blaNDM-1 pathogens using membrane-active molecules advocates their potential for synergistic co-delivery of antibiotics to combat Gram-negative superbugs. PMID:25789871

  9. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2016-04-01

    Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

  10. Biodegradation of cresol isomers in anoxic aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Smolenski, W.J.; Suflita, J.M.

    1987-04-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers wer preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradations of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol metabolism transformed this substrate at 18 and 330 nmol/h per g (dry weight) for MC and SRC, respectively. Inhibition of electron flow to sulfate reduction with 2.0 mM molybdate reduced p-cresol metabolism in incubations containing sulfate. When methanogenesis was blocked with 5 mM bromoethanesulfonic acid in incubations lacking sulfate, p-cresol catabolism was retarded. Under SRC 3.4 mol of sulfate was consumed per mol of p-cresol metabolized. The addition of sulfate to methanogenic incubations stimulated p-cresol degradation. Simultaneous adaptation studies in combination with spectrophotometric and chromatographic analysis of metabolites indicated that p-cresol was oxidized under SRC to p-hydroxybenzoate via the corresponding alcohol and aldehyde. This series of reactions was inhibited under sulfate-limited or aerobic conditions. Therefore, the primary catabolic event for p-cresol decomposition under SRC appears to involve the hydroxylation of the aryl methyl group.

  11. Optimization of low ring polycylic aromatic biodegradation

    Science.gov (United States)

    Othman, N.; Abdul-Talib, S.; Tay, C. C.

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are recalcitrance and persistence that finally turn into problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment due to its organic criteria. This study is carried out to optimize degradation process of low ring PAHs. Bacteria used in this study was isolated from sludge collected from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Working condition namely, substrate concentration, bacteria concentration, pH and temperature were optimized. PAHs in the liquid sample was extracted by using solid phase microextractio equipped with a 7 µm polydimethylsiloxane (PDMS) SPME fibr. Removal of PAHs were assessed by measuring PAHs concentration using GC-FID. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mgL-1 of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. These working condition had proved the effectiveness of using bacteria in biodegradation process of PAHs.

  12. Monitoring Biodegradation of Magnesium Implants with Sensors

    Science.gov (United States)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  13. Immunological Response to Biodegradable Magnesium Implants

    Science.gov (United States)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  14. Modification of Biodegradable Polyesters Using Electron Beam

    International Nuclear Information System (INIS)

    Poly(4-Hydroxybutyrate) P4HB, Poly(butylene succinate-co-adipate) PBSA and Poly(ε-caprolactone) PCL were electron beam (EB)-irradiated. Poly(4-Hydroxybutyrate) was irradiated without any polyfunctional monomers (PFM). While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC), Polyethyleneglycol dimethacrylate (2G, 4G), Trimethylolpropane trimethacrylate (TMPT) and Tetramethylolmethane tetraacrylate (A-TMMT) at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel) was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields. (author)

  15. A REVIEW ON BIODEGRADABLE STARCH BASED FILM

    Directory of Open Access Journals (Sweden)

    Hooman Molavi

    2015-04-01

    Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

  16. NEW DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Sarkar Biresh K

    2011-05-01

    Full Text Available Incorporating an existing medicine into a new drug delivery system can significantly improve its performance in terms of efficacy, safety, and improved patient compliance. The need for delivering drugs to patients efficiently and with fewer side effects has prompted pharmaceutical companies to engage in the development of new drug delivery systems. Today, drug delivery companies are engaged in the development of multiple platform technologies for controlled release, delivery of large molecules, liposome, taste-masking, oral fast- dispersing dosage forms, technology for in- soluble drugs, and delivery of drugs through intranasal, pulmonary, transdermal, vaginal, colon, and transmucosal routes.

  17. Status Report from the Scientific Panel on Antibiotic Use in Dermatology of the American Acne and Rosacea Society: Part 1: Antibiotic Prescribing Patterns, Sources of Antibiotic Exposure, Antibiotic Consumption and Emergence of Antibiotic Resistance, Impact of Alterations in Antibiotic Prescribing, and Clinical Sequelae of Antibiotic Use.

    Science.gov (United States)

    Del Rosso, James Q; Webster, Guy F; Rosen, Ted; Thiboutot, Diane; Leyden, James J; Gallo, Richard; Walker, Clay; Zhanel, George; Eichenfield, Lawrence

    2016-04-01

    Oral and topical antibiotics are commonly prescribed in dermatologie practice, often for noninfectious disorders, such as acne vulgaris and rosacea. Concerns related to antibiotic exposure from both medical and nonmedical sources require that clinicians consider in each case why and how antibiotics are being used and to make appropriate adjustments to limit antibiotic exposure whenever possible. This first article of a three-part series discusses prescribing patterns in dermatology, provides an overview of sources of antibiotic exposure, reviews the relative correlations between the magnitude of antibiotic consumption and emergence of antibiotic resistance patterns, evaluates the impact of alterations in antibiotic prescribing, and discusses the potential relevance and clinical sequelae of antibiotic use, with emphasis on how antibiotics are used in dermatology. PMID:27462384

  18. A Polymeric Bowl for Multi-Agent Delivery.

    Science.gov (United States)

    Hyun, Dong Choon

    2015-08-01

    This paper describes a simple system for multi-agent delivery. The system consists of a biodegradable polymer particle with a hollow interior, together with a hole on its surface that can be completely or partially sealed via thermal annealing. A hydrophobic dye, Nile-red, entrapped within the shell of hollow particles presents a sustained release behavior while methylene blue, a hydrophilic model agent, encapsulated in the hollow interior shows a fast release manner. The release profiles of the probes can be further independently controlled by encapsulating methylene blue-loaded polymer nanoparticles, instead of free dye, in the hollow particle with a small hole on its surface. PMID:26033149

  19. Red Blood Cell Membrane-Cloaked Nanoparticles For Drug Delivery

    Science.gov (United States)

    Carpenter, Cody Westcott

    Herein we describe the development of the Red Blood Cell coated nanoparticle, RBC-NP. Purified natural erythrocyte membrane is used to coat drug-loaded poly(lacticco-glycolic acid) (PLGA). Synthetic PLGA co-polymer is biocompatible and biodegradable and has already received US FDA approval for drug-delivery and diagnostics. This work looks specifically at the retention of immunosuppressive proteins on RBC-NPs, right-sidedness of natural RBC membranes interfacing with synthetic polymer nanoparticles, sustained and retarded drug release of RBC-NPs as well as further surface modification of RBC-NPs for increased targeting of model cancer cell lines.

  20. Topical and oral antibiotics for acne vulgaris.

    Science.gov (United States)

    Del Rosso, James Q

    2016-06-01

    Antibiotics, both oral and topical, have been an integral component of the management of acne vulgaris (AV) for approximately 6 decades. Originally thought to be effective for AV due to their ability to inhibit proliferation of Propionibacterium acnes, it is now believed that at least some antibiotics also exert anti-inflammatory effects that provide additional therapeutic benefit. To add, an increase in strains of P acnes and other exposed bacteria that are less sensitive to antibiotics used to treat AV have emerged, with resistance directly correlated geographically with the magnitude of antibiotic use. Although antibiotics still remain part of the therapeutic armamentarium for AV treatment, current recommendations support the following when used to treat AV: 1) monotherapy use should be avoided; 2) use benzoyl peroxide concomitantly to reduce emergence of resistant P acnes strains; 3) oral antibiotics should be used in combination with a topical regimen for moderate-to-severe inflammatory AV; and 4) use oral antibiotics over a limited duration to achieve control of inflammatory AV with an exit plan in place to discontinue their use as soon as possible. When selecting an oral antibiotic to treat AV, potential adverse effects are important to consider. PMID:27416309