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1.
ScientificWorldJournal ; 2021: 9342748, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34712107

RESUMO

Background: Recently, an outbreak of a novel human coronavirus SARS-CoV-2 has become a world health concern leading to severe respiratory tract infections in humans. Virus transmission occurs through person-to-person contact, respiratory droplets, and contaminated hands or surfaces. Accordingly, we aim at reviewing the literature on all information available about the persistence of coronaviruses, including human and animal coronaviruses, on inanimate surfaces and inactivation strategies with biocides employed for chemical and physical disinfection. Method: A comprehensive search was systematically conducted in main databases from 1998 to 2020 to identify various viral disinfectants associated with HCoV and methods for control and prevention of this newly emerged virus. Results: The analysis of 62 studies shows that human coronaviruses such as severe acute respiratory syndrome (SARS) coronavirus, Middle East respiratory syndrome (MERS) coronavirus or endemic human coronaviruses (HCoV), canine coronavirus (CCV), transmissible gastroenteritis virus (TGEV), and mouse hepatitis virus (MHV) can be efficiently inactivated by physical and chemical disinfectants at different concentrations (70, 80, 85, and 95%) of 2-propanol (70 and 80%) in less than or equal to 60 s and 0.5% hydrogen peroxide or 0.1% sodium hypochlorite within 1 minute. Additionally, glutaraldehyde (0.5-2%), formaldehyde (0.7-1%), and povidone-iodine (0.1-0.75%) could readily inactivate coronaviruses. Moreover, dry heat at 56°C, ultraviolet light dose of 0.2 to 140 J/cm2, and gamma irradiation could effectively inactivate coronavirus. The WHO recommends the use of 0.1% sodium hypochlorite solution or an ethanol-based disinfectant with an ethanol concentration between 62% and 71%. Conclusion: The results of the present study can help researchers, policymakers, health decision makers, and people perceive and take the correct measures to control and prevent further transmission of COVID-19. Prevention and decontamination will be the main ways to stop the ongoing outbreak of COVID-19.


Assuntos
COVID-19/prevenção & controle , Desinfetantes/farmacologia , Desinfecção/instrumentação , SARS-CoV-2 , Inativação de Vírus/efeitos dos fármacos , 2-Propanol/farmacologia , Animais , COVID-19/virologia , Coronavirus Canino/efeitos dos fármacos , Desinfecção/métodos , Etanol/farmacologia , Formaldeído/farmacologia , Raios gama , Glutaral/farmacologia , Temperatura Alta , Humanos , Peróxido de Hidrogênio/farmacologia , Camundongos , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Vírus da Hepatite Murina/efeitos dos fármacos , Povidona-Iodo/farmacologia , Vírus da SARS/efeitos dos fármacos , Hipoclorito de Sódio/farmacologia , Vírus da Gastroenterite Transmissível/efeitos dos fármacos , Raios Ultravioleta
2.
World J Microbiol Biotechnol ; 37(10): 174, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34519903

RESUMO

Microbiologically influenced corrosion (MIC) is one of the major corrosion threats in the oil and gas industry. It is caused by environmental biofilms. Glutaraldehyde is a popular green biocide for mitigating biofilms and MIC. This work investigated the efficacy of glutaraldehyde enhancement by food-grade green chemical D-limonene in the biofilm prevention and MIC mitigation using a mixed-culture oilfield biofilm consortium. After 7 days of incubation at 37 °C in enriched artificial seawater in 125 mL anaerobic vials, the 100 ppm (w/w) glutaraldehyde + 200 ppm D-limonene combination treatment reduced the sessile cell counts on C1018 carbon steel coupons by 2.1-log, 1.7-log, and 2.3-log for sulfate reducing bacteria, acid producing bacteria, and general heterotrophic bacteria, respectively in comparison with the untreated control. The treatment achieved 68% weight loss reduction and 78% pit depth reduction. The 100 ppm glutaraldehyde + 200 ppm D-limonene combination treatment was found more effective in biofilm prevention and MIC mitigation than glutaraldehyde and D-limonene used individually. Electrochemical tests corroborated weight loss and pit depth data trends.


Assuntos
Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Desinfetantes/farmacologia , Glutaral/farmacologia , Limoneno/farmacologia , Aço/química , Bactérias/crescimento & desenvolvimento , Corrosão , Campos de Petróleo e Gás , Água do Mar/microbiologia
3.
Biomolecules ; 11(5)2021 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068806

RESUMO

Mitochondria are highly dynamic organelles, constantly undergoing shape changes, which are controlled by mitochondrial movement, fusion, and fission. Mitochondria play a pivotal role in various cellular processes under physiological and pathological conditions, including metabolism, superoxide generation, calcium homeostasis, and apoptosis. Abnormal mitochondrial morphology and mitochondrial protein expression are always closely related to the health status of cells. Analysis of mitochondrial morphology and mitochondrial protein expression in situ is widely used to reflect the abnormality of cell function in the chemical fixed sample. Paraformaldehyde (PFA), the most commonly used fixative in cellular immunostaining, still has disadvantages, including loss of antigenicity and disruption of morphology during fixation. We tested the effect of ethanol (ETHO), PFA, and glutaraldehyde (GA) fixation on cellular mitochondria. The results showed that 3% PFA and 1.5% GA (PFA-GA) combination reserved mitochondrial morphology better than them alone in situ in cells. Mitochondrial network and protein antigenicity were well maintained, indicated by preserved MitoTracker and mitochondrial immunostaining after PFA-GA fixation. Our results suggest that the PFA-GA combination is a valuable fixative for the study of mitochondria in situ.


Assuntos
Fixadores/farmacologia , Formaldeído/farmacologia , Glutaral/farmacologia , Mitocôndrias/ultraestrutura , Polímeros/farmacologia , Animais , Camundongos , Microscopia Confocal , Mitocôndrias/efeitos dos fármacos
4.
Bioessays ; 43(6): e2000312, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33857328

RESUMO

Biocidal agents such as formaldehyde and glutaraldehyde are able to inactivate several coronaviruses including SARS-CoV-2. In this article, an insight into one mechanism for the inactivation of these viruses by those two agents is presented, based on analysis of previous observations during electron microscopic examination of several members of the orthocoronavirinae subfamily, including the new virus SARS-CoV-2. This inactivation is proposed to occur through Schiff base reaction-induced conformational changes in the spike glycoprotein leading to its disruption or breakage, which can prevent binding of the virus to cellular receptors. Also, a new prophylactic and therapeutic measure against SARS-CoV-2 using acetoacetate is proposed, suggesting that it could similarly break the viral spike through Schiff base reaction with lysines of the spike protein. This measure needs to be confirmed experimentally before consideration. In addition, a new line of research is proposed to help find a broad-spectrum antivirus against several members of this subfamily.


Assuntos
Desinfetantes/farmacologia , Corpos Cetônicos/farmacologia , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/metabolismo , Animais , Antivirais/química , Antivirais/farmacologia , Desinfetantes/química , Formaldeído/química , Formaldeído/farmacologia , Glutaral/química , Glutaral/farmacologia , Humanos , Corpos Cetônicos/química , Corpos Cetônicos/metabolismo , Cetose/etiologia , Cetose/virologia , SARS-CoV-2/patogenicidade , Vírion/efeitos dos fármacos , Vírion/patogenicidade
5.
Microscopy (Oxf) ; 70(2): 215-223, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33206169

RESUMO

We have been using sandwich freezing of living yeast and bacteria followed by freeze-substitution for observing close-to-native ultrastructure of cells. Recently, sandwich freezing of glutaraldehyde-fixed cultured cells and human tissues have been found to give excellent preservation of ultrastructure of cells and tissues. These studies, however, have been conducted using a handmade sandwich freezing device and have been limited in a few laboratories. To spread the use of this method to other laboratories, we fabricated and commercialized a new sandwich freezing device. The new device is inexpensive, portable and sterilizable. It can be used to rapid-freeze viruses, bacteria, yeast, cultured cells and animal and human tissues to a depth of 0.2 mm if tissues are prefixed with glutaraldehyde. The commercial availability of this device will expand application of rapid freezing to wide range of biological materials.


Assuntos
Microscopia Crioeletrônica/métodos , Escherichia coli/ultraestrutura , Substituição ao Congelamento/métodos , Mastócitos/ultraestrutura , Saccharomyces cerevisiae/ultraestrutura , Vírus/ultraestrutura , Animais , Congelamento , Glutaral/farmacologia , Humanos , Microtomia/métodos , Pele/citologia , Pele/ultraestrutura
6.
BMC Ophthalmol ; 20(1): 488, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33317477

RESUMO

BACKGROUND: Collagen cross-linking of the sclera is a promising approach to strengthen scleral rigidity and thus to inhibit eye growth in progressive myopia. Additionally, cross-linking might inhibit degrading processes in idiopathic melting or in ocular inflammatory diseases of the sclera. Different cross-linking treatments were tested to increase resistance to enzymatic degradation of the rabbit sclera. METHODS: Scleral patches from rabbit eyes were cross-linked using paraformaldehyde, glutaraldehyde or riboflavin combined with UV-A-light or with blue light. The patches were incubated with collagenase I (MMP1) for various durations up to 24 h to elucidate differences in scleral resistance to enzymatic degradation. Degraded protein components in the supernatant were detected and quantified using measurements of Fluoraldehyde o-Phthaldialdehyde (OPA) fluorescence. RESULTS: All cross-linking methods reduced the enzymatic degradation of rabbit scleral tissue by MMP1. Incubation with glutaraldehyde (1%) and paraformaldehyde (4%) caused nearly a complete inhibition of enzymatic degradation (down to 7% ± 2.8 of digested protein compared to control). Cross-linking with riboflavin/UV-A-light reduced the degradation by MMP1 to 62% ± 12.7 after 24 h. Cross-linking with riboflavin/blue light reduced the degradation by MMP1 to 77% ± 13.5 after 24 h. No significant differences could be detected comparing different light intensities, light exposure times or riboflavin concentrations. CONCLUSIONS: The application of all cross-linking methods increased the resistance of rabbit scleral tissue to MMP1-degradation. Especially, gentle cross-linking with riboflavin and UV-A or blue light might be a clinical approach in future.


Assuntos
Reagentes para Ligações Cruzadas/farmacologia , Metaloproteinase 1 da Matriz/farmacologia , Inibidores de Metaloproteinases de Matriz/farmacologia , Esclera/efeitos dos fármacos , Animais , Colágeno Tipo I/metabolismo , Formaldeído/farmacologia , Glutaral/farmacologia , Polímeros/farmacologia , Coelhos , Riboflavina/farmacologia , Esclera/metabolismo , Raios Ultravioleta
7.
Microbiologyopen ; 9(11): e1117, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32996289

RESUMO

Alkaline glutaraldehyde (GTA) is a high-level chemical disinfectant/sterilant and has a broad microbial kill spectrum. The precise antimicrobial mechanism of GTA remains debated. GTA kill times are extremely variable across different organisms, illustrating the need for a better understanding of GTA kill mechanisms related to different organisms. A commonly proposed GTA kill mechanism suggests that it works by cross-linking accessible primary amines on important surface proteins. If true, the antimicrobial activity of GTA may directly correlate to the number of these available functional groups. Bacillus species form highly resistant bacterial endospores that are commonly used as one of the most stringent test organisms for disinfection and sterilization. In this study, we compared the log reduction times of alkaline GTA on spores from 4 Bacillus species to fluorescent profiles generated using Alexa Fluor™ amine-reactive dyes. GTA kill times were also compared to mean spore coat thicknesses as measured with scanning electron microscopy (SEM). Fluorescence values generated from bound amine-reactive dye showed a strong, positive correlation to GTA susceptibility, as measured by GTA 6-log10 reduction times. Spore coat thickness also showed a strong, positive correlation to reduction time values. Results support the hypothesis that GTA kill times are directly related to the number of available primary amines on bacterial endospores. Results also indicated that the killing efficacy of GTA may be influenced by its ability to penetrate the spore coat to reach additional targets, suggesting that damaging important biomolecules beyond surface proteins may be involved in GTA killing mechanisms.


Assuntos
Aminas/química , Bacillus/efeitos dos fármacos , Bacillus/fisiologia , Desinfetantes/farmacologia , Glutaral/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Bacillus/classificação , Parede Celular/metabolismo , Desinfecção , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Esporos Bacterianos/química , Esporos Bacterianos/fisiologia
8.
Vet Microbiol ; 248: 108791, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32827921

RESUMO

Biocide susceptibility testing (BST) of bacteria lacks standardised methods. Based on a recently established broth macrodilution BST method, a broth microdilution method for BST was developed. To establish the respective protocol, four reference strains Staphylococcus aureus ATCC® 6538, Enterococcus hirae ATCC® 10541, Escherichia coli ATCC® 10536 and Pseudomonas aeruginosa ATCC® 15442 were investigated for their minimal inhibitory concentrations (MICs) towards quaternary ammonium compounds (benzalkonium chloride), cationic compounds (chlorhexidine), aldehydes (glutardialdehyde) and alcohols (isopropanol) using tryptic soy broth. All combinations of (i) inoculum preparation according to the German Veterinary Medical Society (DVG) or the Clinical and Laboratory Standards Institute (CLSI) with some modifications, (ii) use of 1st subculture (SC) and 2nd SC, (iii) direct colony suspension (DCS) with/without glass beads, and (iv) incubation at 37 °C for 24 h, 48 h, and 72 h were compared using seven independent replications. Overall, the reproducibility was high for all abovementioned strain/biocide/parameter combinations. In total, 86.9 % - 100 % of the results were within ± one dilution step of the mode value. The proposed method for a standardised BST protocol comprises (i) two different inoculum densities, (ii) the use of a fresh overnight culture (1st SC or 2nd SC), (iii) the preparation of the inoculum suspension by either of the two methods using DCS with or without glass beads, and (iv) the incubation at 37 °C for 24 h. This broth microdilution method will help to harmonize BST of bacterial pathogens in routine diagnostics.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Desinfetantes/farmacologia , Testes de Sensibilidade Microbiana/métodos , 2-Propanol/farmacologia , Bactérias/classificação , Compostos de Benzalcônio , Clorexidina/farmacologia , Glutaral/farmacologia , Reprodutibilidade dos Testes
9.
Int J Biol Macromol ; 164: 677-686, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645500

RESUMO

Basa acellular dermal matrix (BADM) has advantages in the preparation of oral prosthetic membranes. In order to prepare high-quality BADM, a suitable cross-linking agent is necessary. In this study, acellular dermal matrix was prepared from basa fish skin and then cross-linked with carbodiimide (EDC), oxidized chitosan oligosaccharide (OCOS) and glutaraldehyde (GA), respectively. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis (XRD), histological staining, DNA electrophoresis and the limulus amoebocyte lysate chromogenic assay were used to detect the structure and properties of BADM. The compatibility of BADM was detected by implantation in vivo and cell experiments. The results showed that the majority of the cellular and DNA in BADM were removed. The endotoxin was not be detected. Furthermore, the structure of BADM was not destroyed. The mechanical and anti-degraded properties of BADM were promoted obviously after cross-linking. The thermal shrinkage temperatures of wet and dry EDC-BADM (BADM cross-linked by carbodiimide) were increased by 39.22 °C and 18.27 °C, respectively, compared with that of the uncross-linked BADM. In addition, the EDC-BADM had good biocompatibility and cytocompatibility. In conclusion, carbodiimide can improve the properties of BADM, which has potential application in the field of biomaterials.


Assuntos
Derme Acelular/efeitos dos fármacos , Carbodi-Imidas/farmacologia , Quitosana/farmacologia , Glutaral/farmacologia , Animais , Carbodi-Imidas/química , Quitosana/química , Reagentes para Ligações Cruzadas/química , Reagentes para Ligações Cruzadas/farmacologia , Peixes , Glutaral/química , Oligossacarídeos/química , Oligossacarídeos/farmacologia , Temperatura
10.
Artif Organs ; 44(11): E482-E493, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32364253

RESUMO

The objective of this study was to evaluate the effect of chemical treatment with glutamic acid to avoid calcification of biological cardiac valves. The bovine pericardium (BP) tissues were fixed with 0.5% glutaraldehyde (BP/GA), followed by treatment with glutamic acid (BP/GA + Glu) for neutralization of the free aldehyde groups. Microscopic analysis showed that the wavy structure of collagen fibrils was preserved, but changes in elastin's integrity occurred. However, the treatment did not promote undesirable changes in the thermal and mechanical properties of the modified BPs. These samples were systematically studied in rat subcutaneous tissue: control (BP/GA) and anticalcificant (BP/GA + Glu). After 60 days, both groups induced similar inflammatory reactions. In terms of calcification, BP/GA + Glu remained more stable with a lower index (3.1 ± 0.2 µg Ca2+ /mg dry tissue), whereas for BP/GA it was 5.7 ± 1.3 µg Ca2+ /mg dry tissue. Bioprostheses made from BP/GA + Glu were implanted in the pulmonary position in sheep, and in vivo echocardiographic analyses revealed maintenance of valvar function after 180 days, with low gradients and minimal valve insufficiency. The explanted tissues of the BP/GA + Glu group had a lower average calcium content 3.8 ± 3.0 µg Ca2+ /mg dry tissue. The results indicated high anticalcification efficiency of BP/GA + Glu in both subcutaneous implant in rats and in the experimental sheep model, which is an advantage that should encourage the industrial application of these materials for the manufacture of bioprostheses.


Assuntos
Bioprótese , Calcificação Fisiológica/efeitos dos fármacos , Bovinos , Ácido Glutâmico/farmacologia , Próteses Valvulares Cardíacas , Animais , Bovinos/fisiologia , Glutaral/farmacologia , Valvas Cardíacas/efeitos dos fármacos , Valvas Cardíacas/fisiologia , Pericárdio/efeitos dos fármacos , Pericárdio/fisiologia
11.
Int Orthod ; 18(2): 380-388, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32037209

RESUMO

OBJECTIVE: The effect of any sterilization methods (cold chemical, or hot) on film removal from coated archwires has not yet been investigated. Thus, we assessed it. MATERIALS AND METHODS: This double-blind randomized clinical trial was performed on 120 observations: 40 macroscopically intact coated archwires from 4 brands were purchased (n=10 archwires/brand). Five wires from each brand underwent cold and 5 underwent hot sterilization. Wires were applied in 40 non-extractions patients at alignment phase of treatment (one month). Afterwards, 3 inter-bracket segments from each wire were examined microscopically, and the percentage of coating loss was recorded for each segment. Coating losses of the 4 brands and 2 sterilization methods were compared using a two-way ANOVA and a Welch t-test (α=0.05). Surfaces were also evaluated using scanning electron microscopy. RESULTS: The mean surface coating loss of hot (autoclave) and cold (glutaraldehyde) sterilization methods was 25.6±28.7 and 28.1±30.8 percent respectively. The mean surface coating removal of the Ortho Organizers, American Orthodontics, SIA, and Gestenco brands were 24.1±28.4, 36.7±36.0, 23.0±24.4, and 23.6±28.0 percent, respectively. The two-way ANOVA indicated a lack of overall significant differences among wire brands (P=0.189) and between sterilization types (P=0.629). However, the interaction of sterilization and brands was significant (P=0.005). CONCLUSIONS: Within the limitations of this 1-month clinical trial limited to 4 coated NiTi archwire brands only, the average coating removal of examined brands might not differ much, amounting to about 26% within a month. Glutaraldehyde and autoclave sterilization might not affect the average speed of coating loss in all brands, although each sterilization method might be favourable for certain brands.


Assuntos
Glutaral/farmacologia , Fios Ortodônticos , Esterilização/métodos , Método Duplo-Cego , Estética Dentária , Humanos
12.
Eur J Clin Microbiol Infect Dis ; 39(6): 1129-1136, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32006178

RESUMO

Biofilm in endoscopes is a major problem that can result in failure of disinfection. We studied the survival of K. pneumoniae in a biofilm formed on endoscope tubes subjected to combined chemical and physical stresses. We monitored bacterial survival in the biofilm after the action of 1% and 2% GTA either immediately or after 15 days of desiccation and described the ability of surviving bacteria to recolonize endoscope tubing in a dynamic model. There were surviving bacteria after 5-min exposure to 2% and 1% GTA. The percentage of survivors after 2% and 1% GTA was greater when the GTA treatment was performed after 15 days of prior desiccation of the biofilm. The survivors were able to recolonize and reform biofilm on abiotic surfaces probably because of the survival of persisters in a viable but non-culturable state in the biofilm. Our findings emphasize that the current guidelines on endoscope reprocessing should be strictly followed but that once constituted the biofilm in endoscope tubing will be very difficult to eradicate with present practices.


Assuntos
Biofilmes/crescimento & desenvolvimento , Dessecação , Endoscópios/microbiologia , Glutaral/farmacologia , Klebsiella pneumoniae/fisiologia , Biofilmes/efeitos dos fármacos , Contagem de Colônia Microbiana , Desinfecção , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/crescimento & desenvolvimento , Viabilidade Microbiana , Estresse Fisiológico
13.
J Hazard Mater ; 386: 121661, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31740302

RESUMO

The desalination and reuse of discharged cooling tower water (CTW) as feed water for the cooling tower could lower the industrial fresh water withdrawal. A potential pre-treatment method before CTW desalination is the use of constructed wetlands (CWs). Biodegradation is an important removal mechanism in CWs. In the present study, the impact of the biocides 2,2-dibromo-2-cyanoacetamide (DBNPA) and glutaraldehyde on the biodegradation process by CW microorganisms was quantified in batch experiments in which benzoic acid was incubated with realistic CTW biocide concentrations. DBNPA had a stronger negative impact on the biodegradation than glutaraldehyde. The combination of DBNPA and glutaraldehyde had a lower impact on the biodegradation than DBNPA alone. UHPLC-qTOF-MS/MS non-target screening combined with data-analysis script 'patRoon' revealed two mechanisms behind this low impact. Firstly, the presence of glutaraldehyde resulted in increased DBNPA transformation to the less toxic transformation product 2-bromo-2-cyanoacetamide (MBNPA) and newly discovered 2,2-dibromopropanediamide. Secondly, the interaction between glutaraldehyde and DBNPA resulted in the formation of new products that were less toxic than DBNPA. The environmental fate and toxicity of these products are still unknown. Nevertheless, their formation can have important implications for the simultaneous use of the biocides DBNPA and glutaraldehyde for a wide array of applications.


Assuntos
Ácido Benzoico/metabolismo , Glutaral/farmacologia , Nitrilas/farmacologia , Biodegradação Ambiental , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Áreas Alagadas
14.
J Biomech ; 99: 109528, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31780124

RESUMO

The reconstruction of the aortic valve using glutaraldehyde-treated autologous pericardium is known as "aortic valve neo-cuspidization" (AVNeo). In-body tissue architecture (iBTA), a cell-free, in vivo tissue-engineering technology that can form autologous implantable tissues of the desired shape by subcutaneous embedding specially designed molds, was used to prepare sheet-like collagenous tissues called "Biosheets". Cylindrical molds with several line slits arranged in an alternating (n = 30) or parallel (n = 36) pattern were subcutaneously embedded in goats (n = 12) for 2 or 3 months. The tubular tissues formed in the molds were dried and then cut in the longitudinal direction, thus obtaining Biosheets (5 × 7 cm). The success rate was 97.6% when using the alternating-pattern molds and 97.2% for the parallel molds. Thickness mapping of the Biosheets showed that their entire surface, except for the line-projection portions, was smooth without any defects. The average wall thickness could be controlled over a range of ca. 0.2-0.5 mm by changing the size of the gap (0.75-1.5 mm) in the molds. The alternating slit-patterned Biosheets were found to be almost isotropic in their mechanical properties (ultimate tensile strength, fracture strain, and Young's modulus). Although the composition of the Biosheet wall was heterogeneous in terms of its density (which varied with the thickness), the breaking strength of all the alternating-patterned Biosheets increased almost linearly with the thickness within the range of the thickness of clinically used glutaraldehyde-treated pericardium as a control, and was larger than that of human aortic valve leaflets. Therefore, the alternating-patterned Biosheets have potential for use in an alternative aortic leaflet material in AVNeo.


Assuntos
Valva Aórtica/citologia , Valva Aórtica/metabolismo , Bioprótese , Colágeno/metabolismo , Próteses Valvulares Cardíacas , Fenômenos Mecânicos , Engenharia Tecidual/métodos , Animais , Valva Aórtica/efeitos dos fármacos , Fenômenos Biomecânicos , Glutaral/farmacologia , Humanos , Pericárdio/efeitos dos fármacos , Pericárdio/transplante , Transplante Autólogo
15.
Int J Biol Macromol ; 152: 930-938, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31794827

RESUMO

The recombinant Sulfurihydrogenibium yellowstonense carbonic anhydrase (SyCA) was covalently bonded on novel polyacrylonitrile (PAN) and polyethylene terephthalate (PET) nanofibers (PAN-PET-PAN donated as AEA) that was first fabricated by electrospinning. The resulting composite materials further crosslinked by the glutaraldehyde, which significantly increased thermostability up to 89.8% and 18.0% after heating at 60 °C for 1 h for immobilized crude and pure SyCA, respectively. After four repetitive attempts in the demonstration of CO2 sequestration, immobilized crude and pure SyCA on AEA also effectively improved the total CaCO3 yields to be 5.8 folds and 2.2 folds compared to free enzyme. Furthermore, the endurance of immobilized crude was investigated on flue gasses, which was retained its activity up to 57% on 50 mM NOx and 61% on 50 mM SOx presence. This is the first report of immobilized thermophilic SyCA on a novel nanofiber at the reusability, durability, sequestration of carbon dioxide, tolerant to sulfur oxides (SOx) and nitrogen oxides (NOx) toxic gases and to prevent air pollution.


Assuntos
Sequestro de Carbono , Anidrases Carbônicas/química , Anidrases Carbônicas/metabolismo , Nanofibras/química , Temperatura , Resinas Acrílicas/química , Bactérias/enzimologia , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Glutaral/farmacologia , Cinética , Minerais/metabolismo , Polietilenotereftalatos/química
16.
Mater Sci Eng C Mater Biol Appl ; 104: 109905, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499975

RESUMO

Collagen fibrils serve as the major template for mineral deposits in both biologically derived and engineered tissues. In recent years certain non-collagenous proteins have been elucidated as important players in differentially modulating intra vs. extra-fibrillar mineralization of collagen. We and others have previously shown that the expression of the collagen receptor, discoidin domain receptor 2 (DDR2) positively correlates with matrix mineralization. The objective of this study was to examine if the ectodomain (ECD) of DDR2 modulates intra versus extra-fibrillar mineralization of collagen independent of cell-signaling. For this purpose, a decellularized collagenous substrate, namely glutaraldehyde fixed porcine pericardium (GFPP) was subjected to biomimetic mineralization protocols. GFPP was incubated in modified simulated body fluid (mSBF) or polymer-induced liquid precursor (PILP) solutions in the presence of recombinant DDR2 ECD (DDR2-Fc) to mediate extra or intra-fibrillar mineralization of collagen. Thermogravimetric analysis revealed that DDR2-Fc increased mineral content in GFPP calcified in mSBF while no significant differences were observed in PILP mediated mineralization. Electron microscopy approaches were used to evaluate the quality and quantity mineral deposits. An increase in the matrix to mineral ratio, frequency of particles and size of mineral deposits was observed in the presence of DDR2-Fc in mSBF. Von Kossa staining and immunohistochemistry analysis of adjacent sections indicated that DDR2-Fc bound to both the matrix and mineral phase of GFPP. Further, DDR2-Fc was found to bind to hydroxyapatite (HAP) particles and enhance the nucleation of mineral deposits in mSBF solutions independent of collagen. Taken together, our results elucidate DDR2 ECD as a novel player in the modulation of extra-fibrillar mineralization of collagen.


Assuntos
Materiais Biomiméticos/farmacologia , Biomineralização , Colágeno/metabolismo , Receptor com Domínio Discoidina 2/química , Animais , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Glutaral/farmacologia , Humanos , Pericárdio/efeitos dos fármacos , Polímeros/farmacologia , Domínios Proteicos , Solubilidade , Análise Espectral Raman , Suínos
17.
J Appl Microbiol ; 127(4): 1148-1156, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278818

RESUMO

AIMS: This study investigated the inhibitory effect of glutaraldehyde (GA) on sour rot in citrus fruit and the underlying antifungal mechanism on mycelial growth of the causative pathogen Geotrichum citri-aurantii. METHODS AND RESULTS: Glutaraldehyde exhibited a strong inhibitory effect on G. citri-aurantii, with a minimum inhibitory and fungicidal concentration (MFC) of 1·00 µl ml-1 . In addition, in vivo application of GA (1 × MFC and 5 × MFC) reduced the disease incidence of sour rot in citrus fruit by 60 and 80% respectively. Scanning electron microscopy results revealed that the morphology of G. citri-aurantii mycelia was greatly altered by GA treatment. Propidium iodide and Calcofluor White Staining revealed that the membrane permeability, rather than the cell wall integrity, of G. citri-aurantii mycelia was severely disrupted after the addition of GA. Massive accumulation of malonaldehyde and reactive oxygen species as well as an increase in lipoxygenase activity were observed. CONCLUSION: These results indicate that GA may inhibit the mycelia growth of G. citri-aurantii through a membrane damage mechanism induced by membrane peroxidation. SIGNIFICANCE AND IMPACT OF THE STUDY: Glutaraldehyde is expected to be a novel fungicide for controlling sour rot in citrus fruit.


Assuntos
Fungicidas Industriais/farmacologia , Geotrichum/efeitos dos fármacos , Glutaral/farmacologia , Citrus/microbiologia , Geotrichum/química , Geotrichum/metabolismo , Doenças das Plantas/microbiologia
18.
PLoS One ; 14(6): e0214656, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31194770

RESUMO

Glutaraldehyde-fixed bovine pericardium is currently the most popular biomaterial utilized in the creation of bioprosthetic heart valves. However, recent studies indicate that glutaraldehyde fixation results in calcification and structural valve deterioration, limiting the longevity of bioprosthetic heart valves. Additionally, glutaraldehyde fixation renders the tissue incompatible with constructive recipient cellular repopulation, remodeling and growth. Use of unfixed xenogeneic biomaterials devoid of antigenic burden has potential to overcome the limitations of current glutaraldehyde-fixed biomaterials. Heart valves undergo billion cycles of opening and closing throughout the patient's lifetime. Therefore, understanding the response of unfixed tissues to cyclic loading is crucial to these in a heart valve leaflet configuration. In this manuscript we quantify the effect of cyclic deformation on cycle dependent strain, structural, compositional and mechanical properties of fixed and unfixed tissues. Glutaraldehyde-fixed bovine pericardium underwent marked cyclic dependent strain, resulting from significant changes in structure, composition and mechanical function of the material. Conversely, unfixed bovine pericardium underwent minimal strain and maintained its structure, composition and mechanical integrity. This manuscript demonstrates that unfixed bovine pericardium can withstand cyclic deformations equivalent to 6 months of in vivo heart valve leaflet performance.


Assuntos
Fenômenos Biomecânicos , Glutaral/farmacologia , Valvas Cardíacas/fisiologia , Preservação de Órgãos/veterinária , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Bioprótese , Bovinos , Análise de Elementos Finitos , Próteses Valvulares Cardíacas , Valvas Cardíacas/efeitos dos fármacos , Suínos , Fixação de Tecidos
19.
J Hosp Infect ; 103(1): 78-84, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31199936

RESUMO

BACKGROUND: Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed. AIM: To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology). METHODS: Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate. FINDINGS: One-percent glutaraldehyde revealed a mean decimal log10 reduction of 1.03 with variable results in the nine laboratories (0.37-1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96-4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log10 reduction of 2.68 (range: 2.35-3.57) and at 4% of 4.61 (range: 3.82-5.71). The residual contamination on the three primarily uncontaminated test fields was <50 cfu/25 cm2 in one out of nine laboratories (0.5%) and in seven out of nine laboratories (4%). CONCLUSION: The interlaboratory reproducibility seems to be robust.


Assuntos
Clostridioides difficile/efeitos dos fármacos , Desinfetantes/farmacologia , Testes de Sensibilidade Microbiana/métodos , Esporos Bacterianos/efeitos dos fármacos , Glutaral/farmacologia , Variações Dependentes do Observador , Ácido Peracético/farmacologia , Reprodutibilidade dos Testes
20.
Analyst ; 144(9): 3136-3143, 2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-30941383

RESUMO

Nosema bombycis (Nb) is the pathogen that causes pebrine in silkworms. Aldehydes are effective disinfectants commonly used in sericulture. However, the precise mechanism of their action on Nb spores remains unclear. Here, we used laser tweezers Raman spectroscopy to investigate the effects of glutaraldehyde and formaldehyde on individual Nb spores, as well as phase contrast microscopy imaging to monitor the germination dynamics of individual treated spores, to acquire a deeper understanding of the mechanism of action of aldehydes and to provide a theoretical reference for establishing an effective strategy for disease control in sericulture. The positions of the Raman peaks remained constant during treatment. The Raman intensity was enhanced and the germination rate of the spores significantly decreased with treatment time. Tlag, the time when individual spores begin to germinate, and Tgerm, the time for complete germination, increased with enhanced treatment. The germination time (ΔTgerm) showed no significant difference from that for untreated spores. Heterogeneity was shown, which is relevant to the resistance of Nb spores to aldehydes. The results indicate that glutaraldehyde and formaldehyde do not destroy the spore wall and plasma membrane, do not cause the leakage of intracellular components, and might not damage the extrusion apparatus. The effects of aldehydes on Nb spores are mainly on the spore coat. They may block the external factors that stimulate spore germination. Single-cell analysis based on novel optical techniques reveals the action of chemical sporicides on microsporidia spores in real time and explains the heterogeneity of cell stress resistance. These applications of new techniques offer new insight into traditional disinfectants.


Assuntos
Desinfetantes/farmacologia , Formaldeído/farmacologia , Glutaral/farmacologia , Nosema/efeitos dos fármacos , Esporos Fúngicos/efeitos dos fármacos , Microscopia de Contraste de Fase/métodos , Pinças Ópticas , Análise de Célula Única/métodos , Análise Espectral Raman/métodos
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