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1.
J Appl Microbiol ; 127(5): 1403-1420, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31410952

RESUMO

Medical devices are an important and growing aspect of healthcare provision and are increasing in complexity to meet established and emerging patient needs. Terminal sterilization plays a vital role in the provision of safe medical devices. While terminal sterilization technologies for medical devices include multiple radiation options, ethylene oxide remains the predominant nonthermal gaseous option, sterilizing c. 50% of all manufactured devices. Vaporized hydrogen peroxide (abbreviated VH2O2 by the International Organization for Standardization) is currently deployed for clinical sterilization applications, where its performance characteristics appear aligned to requirements, constituting a viable alternative low-temperature process for terminal processing of medical devices. However, VH2O2 has operational limitations that create technical challenges for industrial-scale adoption. This timely review provides a succinct overview of VH2O2 in gaseous sterilization and addresses its applicability for terminal sterilization of medical devices. It also describes underappreciated factors such as the occurrence of nonlinear microbial inactivation kinetic plots that may dictate a need to develop a new standard approach to validate VH2O2 for terminal sterilization of medical devices.


Assuntos
Contaminação de Equipamentos/prevenção & controle , Peróxido de Hidrogênio/química , Esterilização/métodos , Bactérias/efeitos dos fármacos , Equipamentos e Provisões Hospitalares/microbiologia , Equipamentos e Provisões Hospitalares/estatística & dados numéricos , Óxido de Etileno/química , Óxido de Etileno/farmacologia , Gases/química , Peróxido de Hidrogênio/farmacologia , Esterilização/instrumentação
2.
Mater Sci Eng C Mater Biol Appl ; 92: 132-142, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30184736

RESUMO

The study describes the detailed examination of the effect of ethylene oxide sterilization on electrospun scaffolds constructed from biodegradable polyesters. Different fibrous layers fabricated from polycaprolactone (PCL) and a copolymer consisting of polylactide and polycaprolactone (PLCL) were investigated for the determination of their mechanical properties, degradation rates and interaction with fibroblasts. It was discovered that the sterilization procedure influenced the mechanical properties of the electrospun PLCL copolymer scaffold to the greatest extent. No effect of ethylene oxide sterilization on degradation behavior was observed. However, a delayed fibroblast proliferation rate was noticed with concern to the ethylene oxide sterilized samples compared to the ethanol sterilization of the materials.


Assuntos
Materiais Biocompatíveis/química , Óxido de Etileno/química , Poliésteres/química , Animais , Materiais Biocompatíveis/metabolismo , Materiais Biocompatíveis/farmacologia , Prótese Vascular , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Módulo de Elasticidade , Óxido de Etileno/farmacologia , Camundongos , Microscopia Eletrônica de Varredura , Nanofibras/química , Poliésteres/metabolismo , Esterilização , Resistência à Tração
3.
J Photochem Photobiol B ; 187: 54-60, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30099269

RESUMO

Over the past decade, the implementation of the novel nanomaterials in the field of nanotechnology for the biomedical applications is essential for the comfort factors such as non-toxicity and biocompatibility in the human biological systems. In this context, a novel synthesis was worked out through bacterial species (citrobacter braakii) in the biofabrication of bioactive gold nanoparticles (Au NPs) for the wound healing management. The biosynthesized Au NPs were further modified and improved its compatibility with polyethylene glycol (PEG) and polycaprolactone (PCL) for formed as Au-PEG/PCL nanocomposites to extent the activity in wound healing application. The combination of bioactive nanoparticles with biocompatible polymeric substances has been upsurges the activity of nanoparticles due to the strong interaction of polymers. The biofabricated Au NPs and its nanocomposites were characterized using UV-Vis, FT-IR, XRD, DLS and TEM studies. Further, the prepared materials were tested in a wound healing model of rat with the wound of 22 mm size. The found results are demonstrated that the improved materials are highly active in growth of keratinocytes proliferation and simultaneously reduce scar formation. After 15 days observations, the wound were almost completely healed by the developed Au- PEG/PCL nanocomposites material which was confirmed by Masson's Trichrome staining histological images and antibacterial efficacy was displayed by the CLSM images. Notably, polymeric Au-PEG/PCL nanocomposites showed no inflammation on the wounded portion and internal implantation on rats thus evidencing it as a safe and biologically very active wound healing agent.


Assuntos
Óxido de Etileno/química , Lactonas/química , Nanopartículas Metálicas/química , Nanocompostos/química , Cicatrização , Animais , Citrobacter/efeitos dos fármacos , Óxido de Etileno/farmacologia , Ouro/química , Lactonas/farmacologia , Nanocompostos/uso terapêutico , Nanocompostos/toxicidade , Tamanho da Partícula , Ratos , Doenças Retais/patologia , Doenças Retais/cirurgia , Espectroscopia de Infravermelho com Transformada de Fourier , Cicatrização/efeitos dos fármacos
4.
J Biomed Mater Res B Appl Biomater ; 106(2): 680-688, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28306194

RESUMO

Half of the female population over age 50 years will experience pelvic organ prolapse. We suggest a new approach based on tissue engineering principles to functionally reconstruct the anatomical structures of the pelvic floor. The aim of this study is to investigate the mechanical performance and effect on collagen and elastin production of a degradable mesh releasing basic fibroblast growth factor (bFGF). Implantation of biodegradable mesh with or without bFGF in their core has been conducted in 40 rats in an abdominal wall defect model. Samples were explanted after 4, 8, and 24 weeks, and tested for mechanical properties and the composition of connective tissue. The study showed an increase in mRNA expression for collagen-I (p = 0.0060) and collagen-III (p = 0.0086) in the 4 weeks group with bFGF. The difference was equalized at 8 and 24 weeks. No difference was found at any time for protein amount for collagen-I, collagen-III, and fibronectin. The amount of collagen decreased from 4 to 24 weeks but the fraction of collagen increased. The maximal load of the newly formed tissue showed no effect of bFGF at any time. Exclusively, histology showed a limited ingrowth of collagen fibers after 4 weeks with bFGF but signs of elastin fibers were seen at 24 weeks. The investigation showed that a biodegradable mesh promotes tissue formation with a promising strength. The mesh with bFGF did not represent any advantage on either long or short term in comparison to the mesh without bFGF. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 680-688, 2018.


Assuntos
Parede Abdominal/patologia , Implantes Absorvíveis , Colágeno Tipo III/metabolismo , Colágeno Tipo I/metabolismo , Elastina/metabolismo , Animais , Colágeno Tipo I/genética , Colágeno Tipo III/genética , Modelos Animais de Doenças , Elastina/genética , Óxido de Etileno/química , Óxido de Etileno/farmacologia , Feminino , Fator 2 de Crescimento de Fibroblastos/química , Fator 2 de Crescimento de Fibroblastos/farmacologia , Fibronectinas/genética , Fibronectinas/metabolismo , Lactonas/química , Lactonas/farmacologia , Diafragma da Pelve/patologia , Ratos , Ratos Wistar , Telas Cirúrgicas , Engenharia Tecidual
5.
Mar Drugs ; 16(1)2017 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-29286293

RESUMO

Red algae of Laurencia continue to provide wide structural diversity and complexity of halogenated C15 acetogenin medium-ring ethers. Here, we described the isolation of three new C15 acetogenins (3-5), and one truncated derivative (6) from Laurencia viridis collected on the Canary Islands. These compounds are interesting variations on the pinnatifidenyne structure that included the first examples of ethynyl oxirane derivatives (3-4). The structures were elucidated by extensive study of NMR (Nuclear Magnetic Resonance) data, J-based configuration analysis and DFT (Density Functional Theory) calculations. Their antiproliferative activity against six human solid tumor cell lines was evaluated.


Assuntos
Acetogeninas/química , Éteres Cíclicos/química , Óxido de Etileno/química , Laurencia/química , Acetogeninas/isolamento & purificação , Acetogeninas/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Óxido de Etileno/isolamento & purificação , Óxido de Etileno/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Conformação Molecular , Estrutura Molecular
6.
J Food Sci ; 82(5): 1208-1215, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28407236

RESUMO

Selected processing methods, demonstrated to be effective at reducing Salmonella, were assessed to determine if spice and herb quality was affected. Black peppercorn, cumin seed, oregano, and onion powder were irradiated to a target dose of 8 kGy. Two additional processes were examined for whole black peppercorns and cumin seeds: ethylene oxide (EtO) fumigation and vacuum assisted-steam (82.22 °C, 7.5 psia). Treated and untreated spices/herbs were compared (visual, odor) using sensory similarity testing protocols (α = 0.20; ß = 0.05; proportion of discriminators: 20%) to determine if processing altered sensory quality. Analytical assessment of quality (color, water activity, and volatile chemistry) was completed. Irradiation did not alter visual or odor sensory quality of black peppercorn, cumin seed, or oregano but created differences in onion powder, which was lighter (higher L* ) and more red (higher a* ) in color, and resulted in nearly complete loss of measured volatile compounds. EtO processing did not create detectable odor or appearance differences in black peppercorn; however visual and odor sensory quality differences, supported by changes in color (higher b* ; lower L* ) and increased concentrations of most volatiles, were detected for cumin seeds. Steam processing of black peppercorn resulted in perceptible odor differences, supported by increased concentration of monoterpene volatiles and loss of all sesquiterpenes; only visual differences were noted for cumin seed. An important step in process validation is the verification that no effect is detectable from a sensory perspective.


Assuntos
Cuminum/química , Óxido de Etileno/farmacologia , Piper nigrum/química , Especiarias/análise , Vapor , Monoterpenos/análise , Sementes/química , Sesquiterpenos/análise
7.
Infect Control Hosp Epidemiol ; 38(2): 136-142, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27866488

RESUMO

BACKGROUND Endoscope-associated infections are reported despite following proper reprocessing methods. Microbiological testing can confirm the adequacy of endoscope reprocessing. Multiple controversies related to the method and interpretation of microbiological testing cultures have arisen that make their routine performance a complex target. OBJECTIVE We conducted a pilot study using disposable bronchoscopes (DBs) to simulate different reprocessing times and soaking times and to compare high-level disinfection versus ethylene oxide sterilization. We also reviewed the time to reprocessing and duration of the procedures. METHODS Bronchoscopes were chosen because an alternative disposable scope is commercially available and because bronchoscopes are more prone to delays in processing. Disposable bronchoscopes were contaminated using a liquid bacterial suspension and were then incubated for 1-4 hours. Standard processing and high-level disinfection were performed on 36 endoscopes. Ethylene oxide sterilization was performed on 21 endoscopes. Endoscope cultures were performed using the standard "brush, flush, brush" technique. RESULTS After brushing was performed, a final water-flush culture procedure was the most effective method of detecting bacterial persistence on the disposable scopes. Klebsiella pneumoniae was the most commonly recovered organism after reprocessing. Ethylene oxide sterilization did not result in total elimination of viable bacteria. CONCLUSION Routine endoscopy cultures may be required to assess the adequacy of endoscopic processing. Infect Control Hosp Epidemiol 2017;38:136-142.


Assuntos
Bactérias/isolamento & purificação , Broncoscópios/microbiologia , Desinfecção/métodos , Equipamentos Descartáveis/microbiologia , Contaminação de Equipamentos , Bactérias/classificação , Óxido de Etileno/farmacologia , Humanos , Projetos Piloto , Fatores de Tempo
8.
J Coll Physicians Surg Pak ; 26(6): 486-9, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27353985

RESUMO

OBJECTIVE: To determine the residing microbial flora of ethylene oxide (EtO) sterilized medical devices and optimization of safe dose of gamma radiation (Cobalt 60 source) for the complete elimination of microbial load. STUDY DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Biotechnology, Lahore College for Women University, Lahore, Pakistan from September 2014 to June 2015. METHODOLOGY: Thirty-six samples of EtO sterilized medical devices of same batch of three different companies were collected for this study. Isolation and enumeration of microbes were done by using different selective and differential media. Gram staining and biochemically characterization by API 20 (Bio Merieux, France) kit was done for identification of the microorganisms. The medical devices having high microbial load were sent to Pakistan Radiation Services (PARAS) for gamma irradiations at 3 different selected doses (20 KGy, 25 KGy, and 30 KGy). RESULTS: Different types of Gram positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus andBacillus subtilis) were isolated from the EtO sterilized samples. Gram negative bacteria and fungi were not detected on these medical devices. Gamma irradiations results showed that 30 KGy was optimized dose for complete elimination of microbial flora on endotracheal, Nelaton, and tracheostomy tubes. CONCLUSION: Gamma radiations (Co 60 source) effectively decontaminate the microbial flora on the equipment previously sterilized by the ethylene oxide gas; and 30 KGy is the optimized dose for all these medical devices.


Assuntos
Desinfetantes/farmacologia , Desinfecção/métodos , Equipamentos e Provisões/microbiologia , Óxido de Etileno/farmacologia , Raios gama , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos da radiação , Esterilização/métodos , Contagem de Colônia Microbiana , Desinfecção/instrumentação , Contaminação de Equipamentos , Segurança de Equipamentos , Humanos , Doses de Radiação
9.
Eur J Med Chem ; 108: 134-140, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26638044

RESUMO

A series of eighteen quinones and structurally-related oxiranes were synthesized and evaluated for in vitro inhibitory activity against the chloroquine-sensitive 3D7 clone of the human malaria parasite Plasmodium falciparum. 2-amino and 2-allyloxynaphthoquinones exhibited important antiplasmodial activity (median inhibitory concentrations (IC50) < 10 µM). Oxiranes 6 and 25, prepared respectively by reaction of α-lapachone and tetrachloro-p-quinone with diazomethane in a mixture of ether and ethanol, exhibited the highest antiplasmodial activity and low cytotoxicity against human fibroblasts (MCR-5 cell line). The active compounds could represent a good prototype for an antimalarial lead molecule.


Assuntos
Antimaláricos/síntese química , Antimaláricos/farmacologia , Óxido de Etileno/química , Óxido de Etileno/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Quinonas/síntese química , Quinonas/farmacologia , Antimaláricos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Óxido de Etileno/síntese química , Fibroblastos/efeitos dos fármacos , Humanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Quinonas/química , Relação Estrutura-Atividade
10.
Exp Parasitol ; 151-152: 28-33, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25662707

RESUMO

Chemotherapy of human African trypanosomiasis (HAT) is unsatisfactory because only a few drugs, with serious side effects and poor efficacy, are available. As drug combination regimes often achieve greater therapeutic efficacy than monotherapies, here the trypanocidal activity of the cysteine protease inhibitor K11777 in combination with current anti-HAT drugs using bloodstream forms of Trypanosoma brucei was investigated. Isobolographic analysis was used to determine the interaction between cysteine protease inhibitors (K11777, CA-074Me and CAA0225) and anti-HAT drugs (suramin, pentamidine, melarsoprol and eflornithine). Bloodstream forms of T. brucei were incubated in culture medium containing cysteine protease inhibitors or anti-HAT drugs alone or in combination at a 1:1 fixed-dose ratio. After 48 h incubation, live cells were counted, the 50% growth inhibition values determined and combination indices calculated. The general cytotoxicity of drug combinations was evaluated with human leukaemia HL-60 cells. Combinations of K11777 with suramin, pentamidine and melarsoprol showed antagonistic effects while with eflornithine a synergistic effect was observed. Whereas eflornithine antagonises with CA-074Me, an inhibitor inactivating the targeted TbCATL only under reducing conditions, it synergises with CAA0255, an inhibitor structurally related to CA-074Me which inactivates TbCATL independently of thiols. These findings indicate an essential role of thiols for the synergistic interaction between K11777 and eflornithine. Encouragingly, the K11777/eflornithine combination displayed higher trypanocidal than cytotoxic activity. The results of this study suggest that the combination of the cysteine protease inhibitor K11777 and eflornithine display promising synergistic trypanocidal activity that warrants further investigation of the drug combination as possible alternative treatment of HAT.


Assuntos
Inibidores de Cisteína Proteinase/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Compostos de Benzil/química , Compostos de Benzil/farmacologia , Inibidores de Cisteína Proteinase/química , Dipeptídeos/química , Dipeptídeos/farmacologia , Combinação de Medicamentos , Interações Medicamentosas , Eflornitina/farmacologia , Óxido de Etileno/análogos & derivados , Óxido de Etileno/química , Óxido de Etileno/farmacologia , Células HL-60 , Humanos , Melarsoprol/farmacologia , Pentamidina/farmacologia , Suramina/farmacologia , Tripanossomicidas/química , Compostos de Vinila/química , Compostos de Vinila/farmacologia
11.
Acta Biomater ; 15: 266-77, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25562573

RESUMO

Infections associated with implanted medical devices are a major cause of nosocomial infections, with serious medical and economic repercussions. A variety of silver-containing coatings have been proposed to decrease the risk of infection by hindering bacterial adhesion and biofilm formation. However, the therapeutic range of silver is relatively narrow and it is important to minimize the amount of silver in the coatings, in order to keep sufficient antibacterial activity without inducing cytotoxicity. In this study, the antibacterial efficiency and biocompatibility of nanocoatings with minimal silver loading (∼0.65 nmol cm(-2)) was evaluated in vitro and in vivo. Titanium substrates were coated by grafting mercaptododecylphosphonic acid (MDPA) monolayers followed by post-reaction with AgNO3. The MDPA/AgNO3 nanocoatings significantly inhibited Escherichia coli and Staphylococcus epidermidis adhesion and biofilm formation in vitro, while allowing attachment and proliferation of MC3T3-E1 preosteoblasts. Moreover, osteogenic differentiation of MC3T3 cells and murine mesenchymal stem cells was not affected by the nanocoatings. Sterilization by ethylene oxide did not alter the antibacterial activity and biocompatibility of the nanocoatings. After subcutaneous implantation of the materials in mice, we demonstrated that MDPA/AgNO3 nanocoatings exhibit significant antibacterial activity and excellent biocompatibility, both in vitro and in vivo, after postoperative seeding with S. epidermidis. These results confirm the interest of coating strategies involving subnanomolar amounts of silver exposed at the extreme surface for preventing bacterial adhesion and biofilm formation on metallic or ceramic medical devices without compromising their biocompatibility.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Organofosfonatos/farmacologia , Prata/farmacologia , Titânio/farmacologia , Animais , Aderência Bacteriana/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Óxido de Etileno/farmacologia , Íons , Camundongos Endogâmicos C57BL , Camundongos SCID , Testes de Sensibilidade Microbiana , Osteogênese/efeitos dos fármacos , Espectroscopia Fotoeletrônica , Soluções , Staphylococcus epidermidis/efeitos dos fármacos , Esterilização
12.
Macromol Biosci ; 15(3): 372-84, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25367414

RESUMO

Uptake of nanoparticles (NPs) affects cell migration but the mechanism remains poorly understood. In this study, the amphiphilic block PCL-PEG nano-micelles with well-controlled hydrophilic/hydrophobic chains were used to investigate the effect of internalized nano-micelles on cancer cell migration. Our results indicated that the nano-micelles with medium PCL and PEG chains increased expression of Rho GTPases and impeded focal adhesion components. This could enhance Hep G2 cell motility. The nano-micelles with large PCL and PEG chains showed lower Rho GTPase levels and higher FA components. This is consistent with slower cell migration. Understanding the mechanism of NPs regulating cell behaviors may help the design of efficient drug delivery systems based on polymer micelles.


Assuntos
Movimento Celular/efeitos dos fármacos , Óxido de Etileno/farmacologia , Interações Hidrofóbicas e Hidrofílicas , Lactonas/farmacologia , Micelas , Nanopartículas/química , Endocitose/efeitos dos fármacos , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células Hep G2 , Humanos , Integrinas/metabolismo , Microscopia Eletrônica de Transmissão , Peso Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Subunidades Proteicas/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo
13.
JAMA Otolaryngol Head Neck Surg ; 141(2): 148-53, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25522126

RESUMO

IMPORTANCE: Tympanostomy tube (TT) biofilm formation may lead to sequelae. OBJECTIVE: To determine whether the acute pathogen Haemophilus influenzae promotes TT attachment and biofilm formation by the chronic pathogen Staphylococcus aureus. DESIGN AND SETTING: Controlled, in vitro microbiological study at an academic research laboratory using TTs treated with 0 (untreated), 10, or 3000 µg/mL ciprofloxacin or ethylene oxide and TTs with and without prior H influenzae exposure. INTERVENTIONS: Fluoroplastic TTs (18 per treatment) were cultured with H influenzae. The TTs were gas-sterilized or exposed to 0, 10, or 3000 µg/mL ciprofloxacin. One-third of the TTs from each treatment group underwent H influenzae counts or scanning electron microscopy (SEM). Another one-third were used for an S aureus attachment assay. The remainder, as well as TTs not exposed to H influenzae, were cultured with S aureus and then treated with oxacillin to kill planktonic S aureus. S aureus counts and SEM were performed. MAIN OUTCOMES AND MEASURES: Attachment and biofilm formation of S aureus on TTs assessed by quantitative bacterial counts and SEM. RESULTS: Mean (SD) H influenzae counts were lower on TTs treated with 3 mg/mL than with 10 µg/mL ciprofloxacin (2.06 × 103 [1.00 × 103] vs 4.21 × 105 [1.67 × 105]; P < .001). Mean (SD) S aureus attachment was higher on TTs with untreated preexisting H influenzae (8.88 × 105 [3.20 × 105]; P < .001) and lower on TTs with prior exposure to H influenzae treated with 10 (3.43 × 104 [2.10 × 104]; P = .006) or 3000 µg/mL ciprofloxacin (6.41 × 102 [3.59 × 102]; P < .001). S aureus biofilm formation was similar across groups, except TTs with prior exposure to H influenzae treated with ciprofloxacin 3 mg/mL, which had significantly less (9.30 × 101 [3.51 × 102]; P < .001). CONCLUSIONS AND RELEVANCE: Exposure to live H influenzae may promote S aureus attachment on TTs. Treatment of H influenzae on TTs with ciprofloxacin, 3 mg/mL, as found in ototopical therapy, may reduce subsequent S aureus attachment and biofilm formation.


Assuntos
Biofilmes/crescimento & desenvolvimento , Haemophilus influenzae/fisiologia , Ventilação da Orelha Média/instrumentação , Staphylococcus aureus/fisiologia , Antibacterianos/farmacologia , Carga Bacteriana , Biofilmes/efeitos dos fármacos , Ciprofloxacino/farmacologia , Desinfetantes/farmacologia , Contaminação de Equipamentos/prevenção & controle , Óxido de Etileno/farmacologia , Haemophilus influenzae/efeitos dos fármacos , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Staphylococcus aureus/efeitos dos fármacos
14.
Artigo em Inglês | MEDLINE | ID: mdl-25529473

RESUMO

2-Hydroxyethylated and oxidative DNA nucleosides (DNA adduct biomarkers), such as O6-(2-hydroxyethyl)-2'-deoxyguanosine (O6HEdG), N6-(2-hydroxyethyl)-2'-deoxyadenosine (N6HEdA), 1-(2-hydroxyethyl)-2'-deoxyadenosine (N1HEdA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG), N2,3-etheno-2'-deoxyguanosine (N2,3-ethenodG), α-methyl-γ-hydroxy-1,N2-propano-2'-deoxyguanosine (CrotondG), are important proposed biomarkers for exploring the genotoxicity mechanism of ethylene oxide (EO) in vivo. A liquid chromatography-tandem mass spectrometric method was developed for the simultaneous determination of O6HEdG, N6HEdA, N1HEdA, 8-OHdG, CrotondG, and N2,3-ethenodG together with regular 2'-deoxyguanosine (dG), and 2'-deoxyadenosine (dA) nucleosides in the DNA extracted from mouse lung tissues for the assessment of exposure to EO after inhalation. The lower limits of quantitation for 8-OHdG, CrotondG, N2,3-EthenodG, O6HEdG, N1HEdA, N6HEdA, dG, and dA were 0.025, 0.00125, 0.025, 0.00125, 0.025, 0.01, 2342, and 2500ng/mL, respectively. The linearity of the calibration curves for all analytes were >0.989. The intra-day assay precision relative standard deviation (RSD) values for quality control (QC) samples for all analytes were ≤13.5% with accuracy values ranging from 86.5% to 111%. The inter-day assay precision (RSD) values for all analytes were ≤18.8% with accuracy values ranging from 87.9% to 119%. This method was used for simultaneous determination of the levels of 8-OHdG, CrotondG, N2,3-EthenodG, O6HEdG, dG, N1HEdA, N6HEdA, and dA in DNA enzymatic hydrolysates from DNA extracted from mouse lung after 12 weeks' inhalation exposure to EO at atmospheric concentrations of 0, 100, and 200ppm. Overall, N2,3-ethenodG was not detected in any samples. 8-OHdG, CrotondG, dG, and dA were all quantifiable in all samples. O6HEdG, N1HEdA, and N6HEdA were quantifiable in most samples and the ratio of the corresponding adduct versus their corresponding DNA base (dG or dA) [×10 (e6)] was increased as the EO exposure concentration increased.


Assuntos
DNA/análise , DNA/química , Óxido de Etileno/farmacologia , Nucleosídeos/análise , Nucleosídeos/química , Animais , Cromatografia Líquida , Masculino , Camundongos , Espectrometria de Massas em Tandem
15.
BMC Genomics ; 15: 443, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24906487

RESUMO

BACKGROUND: Next-generation sequencing sample preparation requires nanogram to microgram quantities of DNA; however, many relevant samples are comprised of only a few cells. Genomic analysis of these samples requires a whole genome amplification method that is unbiased and free of exogenous DNA contamination. To address these challenges we have developed protocols for the production of DNA-free consumables including reagents and have improved upon multiple displacement amplification (iMDA). RESULTS: A specialized ethylene oxide treatment was developed that renders free DNA and DNA present within Gram positive bacterial cells undetectable by qPCR. To reduce DNA contamination in amplification reagents, a combination of ion exchange chromatography, filtration, and lot testing protocols were developed. Our multiple displacement amplification protocol employs a second strand-displacing DNA polymerase, improved buffers, improved reaction conditions and DNA free reagents. The iMDA protocol, when used in combination with DNA-free laboratory consumables and reagents, significantly improved efficiency and accuracy of amplification and sequencing of specimens with moderate to low levels of DNA. The sensitivity and specificity of sequencing of amplified DNA prepared using iMDA was compared to that of DNA obtained with two commercial whole genome amplification kits using 10 fg (~1-2 bacterial cells worth) of bacterial genomic DNA as a template. Analysis showed >99% of the iMDA reads mapped to the template organism whereas only 0.02% of the reads from the commercial kits mapped to the template. To assess the ability of iMDA to achieve balanced genomic coverage, a non-stochastic amount of bacterial genomic DNA (1 pg) was amplified and sequenced, and data obtained were compared to sequencing data obtained directly from genomic DNA. The iMDA DNA and genomic DNA sequencing had comparable coverage 99.98% of the reference genome at ≥1X coverage and 99.9% at ≥5X coverage while maintaining both balance and representation of the genome. CONCLUSIONS: The iMDA protocol in combination with DNA-free laboratory consumables, significantly improved the ability to sequence specimens with low levels of DNA. iMDA has broad utility in metagenomics, diagnostics, ancient DNA analysis, pre-implantation embryo screening, single-cell genomics, whole genome sequencing of unculturable organisms, and forensic applications for both human and microbial targets.


Assuntos
Contaminação por DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , DNA/análise , Óxido de Etileno/farmacologia , Genoma Bacteriano , Genoma Humano , Humanos , Indicadores e Reagentes , Reação em Cadeia da Polimerase , Reprodutibilidade dos Testes
16.
Artigo em Tcheco | MEDLINE | ID: mdl-24755055

RESUMO

PURPOSE OF THE STUDY: Each method of sterilisation has some effect on the structure and properties of UHMWPE and thus also on joint replacement longevity. This study was designed to compare, using objective methods of measurement, several kinds of sterilisation and to recommend the one which has the best prospect for making joint replacements last longer. MATERIAL AND METHODS: Two groups of UHMWPE samples were tested. Group 1 included virgin GUR 1020 polyethylene, non-modified and non-sterilised (Meditech, Germany). Group 2 comprised of three sets of samples sterilised with formaldehyde, gamma irradiation and ethylene oxide, respectively. In both groups, physicochemical properties were assessed by infrared spectroscopy (IR), and the oxidation (OI) and trans-vinyl (VI) indices, which show the degree of oxidation of a material, were determined. Free-radical concentrations were measured by the method of electron spin resonance (ESR). The mechanical properties of each sample were studied using small punch tests (SPT) and testing microhardness (MH). Any change in mechanical properties can affect, to various degrees, the quality and longevity of a prosthetic joint. RESULTS: The samples sterilised by gamma irradiation showed higher values of both the OI (0.37) and the VI index (0.038) than the other samples (OI, 0.02 to 0.05 and VI, 0). Also, the free-radical concentration was detectable only in the gamma-sterilised sample. Values obtained for mechanical properties were as follows: peak load in the range of 58.48 N (gamma irradiation) to 59.60 N (ethylene oxide); ultimate load in the range of 46.69 N (gamma irradiation) to 57.50 N (ethylene oxide); ultimate displacement in the range of 4.29 mm (gamma irradiation) to 4.58 mm (virgin polyethylene and formaldehyde); and work to failure in the range of 185.18 mJ (gamma irradiation) to 205.89 mJ (virgin polyethylene). Microhardness values were obtained in the following ranges: 41.2 to 44.6 MPa (virgin polyethylene); 40.2 to 44.1 MPa (formaldehyde); 46.1 to 49.3 MPa (gamma irradiation); and 40.3 to 44.2 MPa (ethylene oxide). DISCUSSION: The samples sterilised with formaldehyde and ethylene oxide have mechanical properties very similar to virgin polyethylene, they are not damaged by oxidation and do not contain free radicals. Owing to these characteristics, the immediate and long-term oxidation stability of the three samples is higher. The sample sterilised by gamma irradiation showed the presence of free radicals and immediate and long-term oxidative degradation. This results in the deterioration of mechanical properties and the growth of crystallinity due to enhanced oxidation and leads to higher polyethylene microhardness. CONCLUSIONS: Sterilisation with gamma irradiation results in oxidative degradation and mechanical property deterioration, which is one of the potential risks of a shorter life span of joint replacements. The use of ethylene oxide or formaldehyde does not change polymer properties nor has any effect on oxidation of materials. Therefore, a longer life expectancy of the joint replacements sterilised with ethylene oxide can be expected. The life span of their joint replacements is a key issue for the patients. Prosthetic joint loosening is painful and the patient often requires re-implantation. A higher number of re-implantations is associated with higher costs for the institution involved and, consequently, for the whole health care system. Although this study basically deals with chemical issues, it informs the surgeon of the latest developments leading to the improvement of implanted materials, which can increase the life expectancy of joint replacements and patients' satisfaction.


Assuntos
Artroplastia de Substituição/métodos , Óxido de Etileno/farmacologia , Formaldeído/farmacologia , Raios gama , Prótese Articular , Esterilização/métodos , Pesquisa Comparativa da Efetividade , Humanos , Prótese Articular/efeitos adversos , Prótese Articular/classificação , Teste de Materiais/métodos , Polietileno/uso terapêutico , Falha de Prótese , Espectrofotometria Infravermelho/métodos
17.
Vet Surg ; 43(8): 1009-13, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24617928

RESUMO

OBJECTIVE: To evaluate the efficacy of steam and ethylene oxide (EtO) sterilization of Vetrap™ bandages. STUDY DESIGN: Prospective experimental study. SAMPLE POPULATION: Vetrap™ bandages (n = 70; 35 as supplied by the manufacturer, 35 unwound and tightly rewound). METHODS: Vetrap™ bandage rolls (n = 60) marked with a 1 cm square were inoculated with 0.1 mL Geobacillus stearothermophilus spores, packaged in a pouch together with independent sterilization indicators and assigned into 3 sub-groups for sterilizer type: dynamic air removal, gravity displacement, and bench-top pre-vacuum and further sub-divided into 2 sterilization temperatures. Vetrap™ bandages rolls (n = 10) were inoculated with 0.1 mL Bacillus atrophaeus spores in the same manner and underwent EtO sterilization. After sterilization, the 1 cm marked square was aseptically resected to the level of the cardboard tube and enriched in a flask containing 10 mL tryptic soy broth for 24 hours at 60°C for G. stearothermophilus and 37°C for B. atrophaeus. Aliquots were subsequently plated on a Petri dish of tryptic soy agar and incubated at 60°C for G. stearothermophilus and 37°C for B. atrophaeus for 24 hours. Samples were scored positive if colonies of indicator organism were present on the nutrient agar after 24 hours. RESULTS: Three Vetrap™ bandages yielded post-sterilization growth of G. stearothermophilus: 2 from the dynamic air removal sterilizer at 134°C for 3.5 minutes, and 1 from the bench-top pre-vacuum sterilizer at 121°C for 15 minutes. After EtO sterilization, no positive samples were detected. CONCLUSIONS: Steam sterilization may be incomplete for Vetrap™ bandages whereas EtO showed complete destruction of resistant bacterial spores.


Assuntos
Vapor , Esterilização/métodos , Animais , Bacillus/efeitos dos fármacos , Bacillus/crescimento & desenvolvimento , Bandagens , Óxido de Etileno/farmacologia , Geobacillus stearothermophilus/efeitos dos fármacos , Geobacillus stearothermophilus/crescimento & desenvolvimento , Látex , Estudos Prospectivos , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/crescimento & desenvolvimento
18.
J Biomed Mater Res B Appl Biomater ; 102(4): 869-76, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24259492

RESUMO

Silk fibroin has been widely explored for many biomedical applications, due to its biocompatibility and biodegradability. Sterilization is a fundamental step in biomaterials processing and it must not jeopardize the functionality of medical devices. The aim of this study was to analyze the influence of different sterilization methods in the physical, chemical, and biological characteristics of dense and porous silk fibroin membranes. Silk fibroin membranes were treated by several procedures: immersion in 70% ethanol solution, ultraviolet radiation, autoclave, ethylene oxide, and gamma radiation, and were analyzed by scanning electron microscopy, Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction, tensile strength and in vitro cytotoxicity to Chinese hamster ovary cells. The results indicated that the sterilization methods did not cause perceivable morphological changes in the membranes and the membranes were not toxic to cells. The sterilization methods that used organic solvent or an increased humidity and/or temperature (70% ethanol, autoclave, and ethylene oxide) increased the silk II content in the membranes: the dense membranes became more brittle, while the porous membranes showed increased strength at break. Membranes that underwent sterilization by UV and gamma radiation presented properties similar to the nonsterilized membranes, mainly for tensile strength and FTIR results.


Assuntos
Fibroínas , Membranas Artificiais , Seda , Esterilização/métodos , Animais , Bombyx , Células CHO , Cricetinae , Cricetulus , Etanol/farmacologia , Óxido de Etileno/farmacologia , Fibroínas/química , Fibroínas/efeitos dos fármacos , Fibroínas/efeitos da radiação , Fibroínas/toxicidade , Raios gama , Temperatura Alta , Umidade , Teste de Materiais , Porosidade , Seda/química , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Resistência à Tração , Raios Ultravioleta , Difração de Raios X
19.
Chirurgia (Bucur) ; 108(6): 840-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24331324

RESUMO

BACKGROUND AND AIM: Prosthetic mesh repair for abdominal wall hernias is widely used because of its technical simplicity and low hernia recurrence rates. The most commonly used material is pure polypropylene mesh, although newer composite materials are recommended by some centers due to their advantages.However, these meshes are more expensive than pure polypropylene meshes. Resterilization of a pure polypropylene mesh has been shown to be quite safe, and many centers prefer slicing a large mesh into smaller pieces, suitable for any hernia type or defect size. Nevertheless there is no data about the safety after resterilization of the composite meshes. The present study was carried out to investigate the effects of resterilization and in vitro degradation in phosphate buffered saline solution on the physical structure and the mechanical properties of partially absorbable lightweight meshes. METHODS: Two composite meshes were used in the study: One mesh consists of monofilament polypropylene and monofilament polyglecaprone -a copolymer of glycolide and epsilon(ε)- caprolactone - (Ultrapro®, 28 g m2, Ethicon, Hamburg,Germany), and the other one consisted of multifilament polypropylene and multifilament polyglactine (Vypro II®, 30g m2, Ethicon, Hamburg, Germany). Two large meshes were cut into rectangular specimens sized 50 x 20 mm for mechanical testing and 20 x 20 mm for in vitro degradation experiments.Meshes were divided into control group with no resterilization and gas resterilization. Ethylene oxide gas sterilization was performed at 55°C for 4.5 hours. In vitro degradation in 0.01M phosphate buffered saline (PBS, pH 7.4) solution at 37 ± 1°C for 8 weeks was applied to one subgroup in each mesh group. Tensiometric measurements and scanning electronmicroscopic evaluations were completed for control and resterilization specimens. RESULTS: Regardless of resterilization, when the meshes were exposed to in vitro degradation, all mechanical parameters decreased significantly. Highest reduction in mechanical properties was observed for Ultrapro due to the degradation of absorbable polyglecaprone and polyglactin parts of these meshes. It was observed that resterilization by ethylene oxide did not determine significant difference on the degradation characteristics and almost similar physical structures were observed for resterilized and non-resterilized meshes. For VyproII meshes, no significant mechanical difference was observed between resterilized and non-resterilized meshes after degradation while resterilized Ultrapro meshes exhibited stronger characteristics than non-resterilized counterparts, after degradation. CONCLUSION: Resterilization with ethylene oxide did not affect the mechanical properties of partially absorbable compositemeshes. No important surface changes were observed inscanning electron microscopy after resterilization.


Assuntos
Desinfetantes/farmacologia , Óxido de Etileno/farmacologia , Polipropilenos , Esterilização , Telas Cirúrgicas , Técnicas In Vitro , Teste de Materiais , Esterilização/métodos , Resistência à Tração
20.
Am J Vet Res ; 74(6): 934-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23718663

RESUMO

OBJECTIVE: To determine the efficacy of decontamination and sterilization of a disposable port intended for use during single-incision laparoscopy. SAMPLE: 5 material samples obtained from each of 3 laparoscopic surgery ports. PROCEDURES: Ports were assigned to undergo decontamination and ethylene oxide sterilization without bacterial inoculation (negative control port), with bacterial inoculation (Staphylococcus aureus, Escherichia coli, and Mycobacterium fortuitum) and without decontamination and sterilization (positive control port), or with bacterial inoculation followed by decontamination and ethylene oxide sterilization (treated port). Each port underwent testing 5 times; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture testing was performed. Bacteriologic culture scores were determined for each port sample. RESULTS: None of the treated port samples had positive bacteriologic culture results. All 5 positive control port samples had positive bacteriologic culture results. One negative control port sample had positive bacteriologic culture results; a spore-forming Bacillus sp organism was cultured from that port sample, which was thought to be an environmental contaminant. Bacteriologic culture scores for the treated port samples were significantly lower than those for the positive control port samples. Bacteriologic culture scores for the treated port samples were not significantly different from those for negative control port samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated standard procedures for decontamination and sterilization of a single-use port intended for use during singleincision laparoscopic surgery were effective for elimination of inoculated bacteria. Reuse of this port may be safe for laparoscopic surgery of animals.


Assuntos
Bactérias/efeitos dos fármacos , Desinfecção/métodos , Equipamentos Descartáveis/veterinária , Óxido de Etileno/farmacologia , Laparoscopia/veterinária , Instrumentos Cirúrgicos/veterinária , Equipamentos Descartáveis/microbiologia , Laparoscopia/instrumentação , Instrumentos Cirúrgicos/microbiologia
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