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1.
Appl Microbiol Biotechnol ; 108(1): 264, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38489042

RESUMO

Cyanophycin (CGP) is a polypeptide consisting of amino acids-aspartic acid in the backbone and arginine in the side chain. Owing to its resemblance to cell adhesive motifs in the body, it can be considered suitable for use in biomedical applications as a novel component to facilitate cell attachment and tissue regeneration. Although it has vast potential applications, starting with nutrition, through drug delivery and tissue engineering to the production of value-added chemicals and biomaterials, CGP has not been brought to the industry yet. To develop scaffolds using CGP powder produced by bacteria, its properties (e.g., biocompatibility, morphology, biodegradability, and mechanical strength) should be tailored in terms of the requirements of the targeted tissue. Crosslinking commonly stands for a primary modification method for renovating biomaterial features to these extents. Herein, we aimed to crosslink CGP for the first time and present a comparative study of different methods of CGP crosslinking including chemical, physical, and enzymatic methods by utilizing glutaraldehyde (GTA), UV exposure, genipin, 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS), and monoamine oxidase (MAO). Crosslinking efficacy varied among the samples crosslinked via the different crosslinking methods. All crosslinked CGP were non-cytotoxic to L929 cells, except for the groups with higher GTA concentrations. We conclude that CGP is a promising candidate for scaffolding purposes to be used as part of a composite with other biomaterials to maintain the integrity of scaffolds. The initiative study demonstrated the unknown characteristics of crosslinked CGP, even though its feasibility for biomedical applications should be confirmed by further examinations. KEY POINTS: • Cyanophycin was crosslinked by 5 different methods • Crosslinked cyanophycin is non-cytotoxic to L929 cells • Crosslinked cyanophycin is a promising new material for scaffolding purposes.


Assuntos
Materiais Biocompatíveis , Tecidos Suporte , Tecidos Suporte/química , Materiais Biocompatíveis/química , Proteínas de Bactérias , Engenharia Tecidual/métodos , Glutaral , Reagentes de Ligações Cruzadas/química
2.
J Contemp Dent Pract ; 25(1): 52-57, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38514431

RESUMO

AIM: The aim of this study was to assess the impact of Nd:YAG laser, glutaraldehyde-based desensitizer (GD), or their combination on occluding dentinal tubules. MATERIALS AND METHODS: Fifty dentin samples were obtained from non-carious human third molars and randomly divided into five groups (n = 10): (1) Control group treated with 37% phosphoric acid, (2) GD group, (3) Nd:YAG laser group (1064 nm, 100 µs, 10 Hz, 300 µm fiber, 1 W power, 100 mJ energy, and 85 J/cm2 energy density), (4) GD followed by Nd:YAG laser group, and (5) Nd:YAG laser followed by GD group. Scanning electron microscopy (SEM) was used to capture five images from each sample for analysis of dentinal tubules using Image J software. SEM/EDX elemental analysis was performed to determine the main mineral contents. Data analyzed using one-way ANOVA and Tukey's post hoc test for statistical comparisons. RESULTS: Laser and combination groups showed a significant decrease in dentinal tubule counts compared with the control and GD groups (p < 0.0001). There were no significant differences in open dentinal tubule counts between the control and GD groups, as well as between the laser and combination groups. However, significant differences were observed in the total area, average size of the tubules, and percentage area between the control group and the treatment groups (GD, laser, GD + laser, laser + GD). No significant difference was found in the Ca/P ratio between the tested groups. CONCLUSION: The use of Nd:YAG laser alone or in combination with GD was more effective in occluding dentinal tubules compared to GD alone. CLINICAL SIGNIFICANCE: This study has shown that Nd:YAG laser alone and in combination with GD has superior dentinal tubule occlusion in vitro. Its clinical use in the treatment of dentinal hypersensitivity may overcome the drawback of conventional treatment approaches for dentin hypersensitivity needing repeated applications to achieve continuous relief from pain since acidic diet and toothbrushing result in the continuing elimination of precipitates and surface coatings. How to cite this article: Alzarooni AH, El-Damanhoury HM, Aravind SS, et al. Combined Effects of Glutaraldehyde-based Desensitizer and Nd: YAG Laser on Dentinal Tubules Occlusion. J Contemp Dent Pract 2024;25(1):52-57.


Assuntos
Sensibilidade da Dentina , Lasers de Estado Sólido , Humanos , Lasers de Estado Sólido/uso terapêutico , Dentina , Sensibilidade da Dentina/tratamento farmacológico , Glutaral/farmacologia , Glutaral/uso terapêutico , Dente Serotino , Microscopia Eletrônica de Varredura
3.
Ecotoxicol Environ Saf ; 272: 116078, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38335575

RESUMO

Since disinfectants are used all over the world to treat illnesses in people and other animals, they pose a major risk to human health. The comprehensive effects of disinfectant treatments on fish liver, especially the impacts on oxidative stress, toxicological effects, transcriptome profiles, and apoptosis, have not yet been fully analyzed. In the current investigation, healthy grass carp were exposed to 80 µg/L glutaraldehyde or 50 µg/L povidone-iodine for 30 days. First, the findings of enzyme activity tests demonstrated that the administration of glutaraldehyde could considerably increase oxidative stress by lowering T-SOD, CAT, and GPx and raising MDA. Furthermore, KEGG research revealed that exposure to glutaraldehyde and povidone-iodine stimulated the PPAR signal pathway. To further elucidate the transcriptome results, the relative expressions of related DEGs in the PPAR signal pathway were verified. Glutaraldehyde induced apoptosis in liver tissue of grass carp; however, it activated cytotoxicity and apoptosis in grass carp hepatocytes when exposed to glutaraldehyde or povidone-iodine. According to the current study, disinfectants can cause the impairment of the immune system, oxidative stress, and attenuation of the PPAR signal pathway in the liver of grass carp, making them detrimental as dietary supplements for grass carp, particularly in the aquaculture sector.


Assuntos
Carpas , Desinfetantes , Animais , Humanos , Povidona-Iodo/toxicidade , Glutaral/toxicidade , Receptores Ativados por Proliferador de Peroxissomo , Fígado , Hepatócitos , Desinfetantes/toxicidade , Apoptose
4.
Biochem Biophys Res Commun ; 702: 149567, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38335701

RESUMO

Glutaraldehyde (GA) is a protein crosslinker widely used in biochemical and pharmaceutical research because it can rapidly stabilize and immobilize substrates via amine group interactions. However, controlling GA crosslinking is challenging owing to its swift reactivity and the influence of various solution conditions, such as pH and concentrations of the substrate and crosslinker. Although extensive research has focused on GA cross-linking mechanisms, studies on quenching, which is critical for preventing non-specific aggregation during prolonged storage, remain sparse. This study examines the quenching efficiency of a combined amino acid mixture of glycine, histidine, and lysine, which are commonly used as individual quenchers. Our findings, confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis, demonstrate that this amino acid blend offers superior quenching compared to single amino acids, enhancing quenching activity across a wide pH spectrum. These results provide a novel approach for mitigating the high reactivity of GA with implications for improving sample preservation and stabilization in a range of biochemical applications, including microscopy and cell fixation.


Assuntos
Histidina , Lisina , Glutaral/química , Glutaral/farmacologia , Reagentes de Ligações Cruzadas/química , Glicina
5.
J Biomater Appl ; 38(8): 915-931, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38346020

RESUMO

Multifunctional and biodegradable dressings with high mechanical strength and good antibacterial activity are crucial in fundamental health services. This study was initiated to prepare a novel curative wound dressing film consisting of natural biodegradable gelatin (G) and polylactic acid (PLA) with silver nanoparticles (AgNPs) where glutaraldehyde (GA) was used as compatibilizer. The prepared composite films addressed the poor thermal and biological stability of G and the limited fluid retention capacity of PLA. Silver nanoparticles were prepared by basic chemical reduction and reinforced on polymer films using simple solvent casting, which obviated common clinical infections and accelerated wound closure rate (p < .05). Fourier transform infrared (FTIR) studies confirmed composite formation through H-bonding and X-ray diffraction (XRD) revealed increased crystallinity due to incorporating AgNPs. Films with G, PLA & GA (50:50:5 by volume) introduced the best elasticity & strength with excellent fluid retention properties (p < .05). Scanning electron microscopy (SEM) images unfolded surface morphology and presence of agglomerated AgNPs on film surfaces. Prepared films exhibited significant antimicrobial efficacy against Staphylococcus aureus and Pseudomonas sp. and showed excellent cell viability (>97 %) in Vero cell line. Finally, an in vivo mouse model study showed 99.7 % contraction (p < .05) within 12 days, which was most effectual and 12 % faster than conventional gauge bandages. These results demonstrated the promising and cost-effective potential of the prepared film for wound healing.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Camundongos , Prata/farmacologia , Prata/química , Nanopartículas Metálicas/uso terapêutico , Nanopartículas Metálicas/química , Gelatina/química , Antibacterianos/farmacologia , Antibacterianos/química , Poliésteres , Glutaral , Bandagens
6.
J Biomech Eng ; 146(7)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38323667

RESUMO

Healthy articular cartilage is a remarkable bearing material optimized for near-frictionless joint articulation. Because its limited self-repair capacity renders it susceptible to osteoarthritis (OA), approaches to reinforce or rebuild degenerative cartilage are of significant interest. While exogenous collagen crosslinking (CXL) treatments improve cartilage's mechanical properties and increase its resistance to enzymatic degradation, their effects on cartilage lubrication remain less clear. Here, we examined how the collagen crosslinking agents genipin (GP) and glutaraldehyde (GTA) impact cartilage lubrication using the convergent stationary contact area (cSCA) configuration. Unlike classical configurations, the cSCA sustains biofidelic kinetic friction coefficients (µk) via superposition of interstitial and hydrodynamic pressurization (i.e., tribological rehydration). As expected, glutaraldehyde- and genipin-mediated CXL increased cartilage's tensile and compressive moduli. Although net tribological rehydration was retained after CXL, GP or GTA treatment drastically elevated µk. Both healthy and "OA-like" cartilage (generated via enzymatic digestion) sustained remarkably low µk in saline- (≤0.02) and synovial fluid-lubricated contacts (≤0.006). After CXL, µk increased up to 30-fold, reaching values associated with marked chondrocyte death in vitro. These results demonstrate that mechanical properties (i.e., stiffness) are necessary, but not sufficient, metrics of cartilage function. Furthermore, the marked impairment in lubrication suggests that CXL-mediated stiffening is ill-suited to cartilage preservation or joint resurfacing.


Assuntos
Cartilagem Articular , Iridoides , Osteoartrite , Humanos , Lubrificação , Glutaral , Colágeno , Osteoartrite/tratamento farmacológico , Fricção , Estresse Mecânico
7.
Water Environ Res ; 96(2): e10982, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38316397

RESUMO

Polyvinylidene fluoride (PVDF) porous membrane was prepared by a two-step method of surface gelation-immersion precipitation phase inversion. Chitosan/acetic acid solution and glutaraldehyde aqueous solution were sequentially sprayed onto the surface of the PVDF solution film, with chitosan crosslinking and gelation occurring simultaneously on the film surface. The solution film was then immersed in a coagulation bath to obtain a modified PVDF porous membrane. The effect of the crosslinking time of chitosan and glutaraldehyde on the structure and properties of the PVDF porous membrane was discussed. The results showed that with the prolongation of crosslinking time, the surface structure of the membrane changed from a dense skin layer to a porous structure; the porosity and the mean pore size of the modified PVDF membranes increased first and then decreased, and the contact angle gradually decreased. When the crosslinking time extended to 15 min, the water flux of modified membrane (M153) reached a maximum value. BSA dynamic cyclic filtration experiment showed that the retention rate (R) of the modified membrane was significantly improved, compared to 68.3% retention rate of the blank membrane (M000), but the crosslinking time had little effect on the retention rates of the four modified membranes. The antifouling data showed that the flux recovery rate of the blank membrane was 73.0%, while the flux recovery rate of the modified membrane can reach as high as 84.40%, and the irreversible pollution rate of the blank membrane was 27.7%, while the irreversible pollution rate of the modified membrane reduced to 15.6%. These results indicated that, after surface chitosan crosslinking, the hydrophilicity and antifouling properties of PVDF membranes were improved. PRACTITIONER POINTS: Modified PVDF membranes with crosslinking CS coating were prepared by a two-step method of surface gelation-immersion precipitation phase inversion. -OH groups and -NH2 groups of CS coating improve the hydrophilicity and the antifouling property of modified PVDF membranes. Modified PVDF membranes had larger mean pore size and higher porosity than unmodified membrane. Flux recovery rates of the modified membranes were higher than that of unmodified membrane. Pollution degree, reversible pollution rate, and irreversible pollution rate of modified membranes were lower than those of unmodified membrane.


Assuntos
Incrustação Biológica , Quitosana , Polímeros de Fluorcarboneto , Polivinil , Quitosana/química , Glutaral , Imersão , Membranas Artificiais , Água
8.
Mycotoxin Res ; 40(1): 175-186, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38224413

RESUMO

Aflatoxin B1 is a highly carcinogenic and teratogenic substance mainly produced by toxin-producing strains such as Aspergillus flavus and Aspergillus parasitic. The efficient decomposition of aflatoxin is an important means to reduce its harm to humans and livestock. In this study, Trametes versicolor aflatoxin B1-degrading enzyme (TV-AFB1D) was recombinantly expressed in Bacillus subtilis (B. subtilis) 168. MMT-CTAB-AFB1D complex was prepared by the immobilization of TV-AFB1D and montmorillonite (MMT) by cross-linking glutaraldehyde. The results indicated that TV-AFB1D could recombinantly express in engineered B. subtilis 168 with a size of approximately 77 kDa. The immobilization efficiency of MMT-CTAB-AFB1D reached 98.63% when the concentration of glutaraldehyde was 5% (v/v). The relative activity of TV-AFB1D decreased to 72.36% after reusing for 10 times. The content of AFB1 in MMT-CTAB-AFB1D-AFB1 decreased to 1.1 µg/g from the initial 5.6 µg/g after incubation at 50 °C for 6 h. The amount of 80.4% AFB1 in the MMT-CTAB-AFB1D-AFB1 complex was degraded by in situ catalytic degradation. Thus, the strategy of combining adsorption and in situ degradation could effectively reduce the content of AFB1 residue in the MMT-CTAB-AFB1D complex.


Assuntos
Aflatoxina B1 , Polyporaceae , Trametes , Humanos , Aflatoxina B1/metabolismo , Trametes/metabolismo , Bentonita , Cetrimônio , Glutaral
9.
Analyst ; 149(4): 1202-1211, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214351

RESUMO

In this study, the carboxy silane 4-(triethoxysilyl)butanoic acid (TESBA) was used to modify titanium dioxide (TiO2) to create a self-assembled monolayer (SAM) and then directionally immobilize a capture antibody using protein A. We selected the amino silane (3-aminopropyl)triethoxysilane (APTES) to perform a comparative analysis with TESBA, and employed glutaraldehyde (GA) as the control. The modification and detection effects and the limit of detection (LOD) were evaluated by detecting human immunoglobulin G (IgG). The average normalized sensitivity of the dual-grating coupler waveguide biosensor was 49.63 ± 0.27 RIU-1 and the optimum resolution was 1.30 × 10-6 RIU. When the SAM was prepared using TESBA and APTES followed by GA, the LOD was 4.59 × 10-7 g mL-1 and 5.29 × 10-7 g mL-1, respectively. We analyzed the modification and detection effects by the t-test and concluded that the differences in the modification effects using TESBA and APTES followed by GA were significant and the differences in the detection effects using TESBA and APTES followed by GA were insignificant. The use of TESBA as the SAM led to the modification effect being superior to that obtained using APTES followed by GA. The detection effect using TESBA was as outstanding as that using APTES followed by GA. Our findings demonstrate the feasibility and effectiveness of using TESBA as the SAM to carboxylate the surface of TiO2, thereby enabling immobilization of biomolecules for human IgG detection.


Assuntos
Imunoglobulina G , Titânio , Humanos , Ácido Butírico , Glutaral
10.
Int J Biol Macromol ; 260(Pt 2): 129362, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272408

RESUMO

The incorporation of a non-specific lipase and a sn-1,3 specific one in a single immobilized system can be a promising approach for the exploitation of both lipases. A one-step immobilization platform mediated by an isocyanide-based multi-component reaction was applied to create co-cross-linked enzymes (co-CLEs) of lipases from Rhizomucor miehei (sn-1,3 specific) and Candida antarctica (non-specific). Glutaraldehyde was found to be effective cross-linker by producing specific activity of 16.9 U/mg and immobilization yield of 99 %. High activity recovery of up to 404 % was obtained for immobilized derivatives. Leaking experiment showed covalent nature of the cross-linking processes. BSA had considerable effect on the immobilization process, providing 87-100 % immobilization yields and up to 10 times improvement in the specific activity of the immobilized derivatives. Scanning electron microscopy images showed flower-like and rod-like structures for the CLEs prepared by glutaraldehyde and undecanedicarboxylic acid, respectively. The prepared co-CLEs were examined in non-selective enrichment of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from fish oil, showing capability of releasing up to 100 % of both omega-3 fatty acids within 8 h of the reaction. The reusability of co-CLEs in five successive cycles presented retaining 63-72 % of their initial activities after the fifth reuse cycle in the hydrolysis reaction.


Assuntos
Ácidos Graxos Ômega-3 , Proteínas Fúngicas , Ácidos Graxos Ômega-3/química , Óleos de Peixe/química , Glutaral , Enzimas Imobilizadas/química , Lipase/química , Rhizomucor
11.
Int J Biol Macromol ; 262(Pt 1): 129730, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38280694

RESUMO

Novel chitosan polymers were synthesized using two cross-linkers, Glutaraldehyde and Terephthaldehyde, to enhance stability and efficiency. Characterization techniques (XRD, FTIR, FE-SEM, TGA, DTG, BJH, and BET) confirmed successful synthesis. These polymers were employed as adsorbents for removing Malachite Green (MG) and Congo Red (CR) dyes from water. Batch experiments and DFT calculations investigated the adsorption process, thermodynamics, and kinetics. Results showed the CSGT-III polymer achieved the highest removal efficiency. For initial dye concentrations ([CR]o = 50 mg/L, [MG]o = 20 mg/L) and adsorbent doses (0.8 g/L for CR, 0.4 g/L for MG), removal efficiencies were 96.99 % for CR and 99.07 % for MG. Thermodynamic analysis confirmed the spontaneous nature of adsorption, and the process was endothermic for both dyes. The Langmuir model fitted adsorption isotherms well, indicating a homogeneous surface. Kinetic analysis revealed a pseudo-second-order model for both dyes.


Assuntos
Quitosana , Corantes de Rosanilina , Poluentes Químicos da Água , Corantes/análise , Glutaral , Cinética , Poluentes Químicos da Água/análise , Vermelho Congo , Termodinâmica , Água , Polímeros , Adsorção , Concentração de Íons de Hidrogênio
12.
PLoS One ; 19(1): e0297149, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38241311

RESUMO

With the emergence of penicillin resistance, the development of novel antibiotics has become an urgent necessity. Semi-synthetic penicillin has emerged as a promising alternative to traditional penicillin. The demand for the crucial intermediate, 6-aminopicillanic acid (6-APA), is on the rise. Enzyme catalysis is the primary method employed for its production. However, due to certain limitations, the strategy of enzyme immobilization has also gained prominence. The magnetic Ni0.4Cu0.5Zn0.1Fe2O4 nanoparticles were successfully prepared by a rapid-combustion method. Sodium silicate was used to modify the surface of the Ni0.4Cu0.5Zn0.1Fe2O4 nanoparticles to obtain silica-coated nanoparticles (Ni0.4Cu0.5Zn0.1Fe2O4-SiO2). Subsequently, in order to better crosslink PGA, the nanoparticles were modified again with glutaraldehyde to obtain glutaraldehyde crosslinked Ni0.4Cu0.5Zn0.1Fe2O4-SiO2-GA nanoparticles which could immobilize the PGA. The structure of the PGA protein was analyzed by the PyMol program and the immobilization strategy was determined. The conditions of PGA immobilization were investigated, including immobilization time and PGA concentration. Finally, the enzymological properties of the immobilized and free PGA were compared. The optimum catalytic pH of immobilized and free PGA was 8.0, and the optimum catalytic temperature of immobilized PGA was 50°C, 5°C higher than that of free PGA. Immobilized PGA in a certain pH and temperature range showed better catalytic stability. Vmax and Km of immobilized PGA were 0.3727 µmol·min-1 and 0.0436 mol·L-1, and the corresponding free PGA were 0.7325 µmol·min-1 and 0.0227 mol·L-1. After five cycles, the immobilized enzyme activity was still higher than 25%.


Assuntos
Nanopartículas , Penicilina Amidase , Penicilina Amidase/química , Penicilina Amidase/metabolismo , Glutaral/química , Dióxido de Silício/química , Enzimas Imobilizadas/química , Catálise , Nanopartículas/química , Penicilinas , Fenômenos Magnéticos , Concentração de Íons de Hidrogênio , Temperatura , Estabilidade Enzimática
13.
Int J Biol Macromol ; 259(Pt 2): 129200, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38218266

RESUMO

Food packaging films play a vital role in preserving and protecting food. However, due to their non-biodegradability, conventional packaging materials have led to significant environmental pollution. To overcome this hurdle, we have developed safe, innovative, sustainable and biodegradable packaging materials that can effectively extend the shelf life of food. In this study, two types of cellulose materials cellulose nanofibers (CNF) and carboxymethyl cellulose (CMC) with complementary roles were combined to prepare nanocellulose composite films with high transparency (90.3 %) of a certain thickness (30 ± 0.019 µm) by solution casting method, and their mechanical properties were further optimized by the addition of plasticizer-glycerol (Gly) and cross-linking agent-glutaraldehyde (GA), so as to maintain the strong tensile strength (≈112.60 MPa) and better malleability (4.12 %). In addition, we loaded the natural active agent tea polyphenols (TPs) with different concentrations to study the inhibition effect on E.coli and S.aureus and to simulate food packaging. Finally, we also found that the synthesized nanocellulose composite films can also achieve rapid degradation in a short time through soil burial, water flushing and immersion. The excellent performance demonstrated in this study provides reference value for further replacing petroleum-based materials with biomass materials in the field of food packaging.


Assuntos
Antibacterianos , Embalagem de Alimentos , Embalagem de Alimentos/métodos , Antibacterianos/farmacologia , Água , Glutaral , Celulose
14.
Eur J Oral Sci ; 132(2): e12970, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38173083

RESUMO

This study aimed to evaluate the effect of n-propyl gallate as pre-treatment for resin-dentin bond strength. The dentin pre-treatments evaluated included propyl gallate of concentrations 0.1% (w/v), 1.0% (w/v), and 10.0% (w/v), as well as glutaraldehyde 5.0% (v/v), and distilled water as a control treatment. Dentin specimens were prepared for Fourier Transformed Infrared Spectroscopy (FT-IR) (n = 3/pre-treatment). Pre-treatments were actively applied to dentin blocks before performing the adhesive procedure to composite resin. Microtensile bond strength to dentin (µTBS) (n = 8/pre-treatment) was determined after 24 h and 6 months of storage. Data were submitted to a two-way ANOVA, followed by Tukey's post hoc test. As for FT-IR, propyl gallate 1%-treated specimens presented higher water, carbonate, collagen, and amide absorbance rates compared to other tested groups, while specimens pre-treated with glutaraldehyde and distilled water presented similar absorbance curves. Regarding µTBS, all concentrations of propyl gallate resulted in statistically significant higher bond strength values than distilled water at 24 h. After 6 months of storage, propyl gallate 0.1% was the only group that maintained µTBS over time. Propyl gallate 0.1% might be a suitable dentinal pre-treatment due to being able to present chemical bonds with demineralized dentin and providing resin-dentin bond stability after 6 months of storage.


Assuntos
Colagem Dentária , Galato de Propila , Galato de Propila/análise , Galato de Propila/farmacologia , Adesivos Dentinários/química , Glutaral , Espectroscopia de Infravermelho com Transformada de Fourier , Cimentos de Resina/química , Dentina , Resistência à Tração , Teste de Materiais , Cimentos Dentários/farmacologia , Resinas Compostas/química , Água/química
15.
Biotechnol Lett ; 46(1): 85-95, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38064041

RESUMO

The objective of this study was to obtain sufficient information on the thermal stabilization of a food-grade lipase from Thermomyces lanuginosus (TLL) using the immobilization technique. To do this, a new non-porous support was prepared via the sequential extraction of SiO2 from rice husks, followed by functionalization with (3-aminopropyl) triethoxysilane - 3-APTES (Amino-SiO2), and activation with glutaraldehyde - GA (GA-Amino-SiO2). We evaluated the influence of GA concentration, which varied from 0.25% v v-1 to 4% v v-1, on the immobilization parameters and enzyme thermal stabilization. The thermal inactivation parameters for both biocatalyst forms (soluble or immobilized TLL) were calculated by fitting a non-first-order enzyme inactivation kinetic model to the experimental data. According to the results, TLL was fully immobilized on the external support surface activated with different GA concentrations using an initial protein load of 5 mg g-1. A sharp decrease of hydrolytic activity was observed from 216.6 ± 12.4 U g-1 to 28.6 ± 0.9 U g-1 of after increasing the GA concentration from 0.25% v v-1 to 4.0% v v-1. The support that was prepared using a GA concentration at 0.5% v v-1 provided the highest stabilization of TLL - 31.6-times more stable than its soluble form at 60 °C. The estimations of the thermodynamic parameters, e.g., inactivation energy (Ed), enthalpy (ΔH#), entropy (ΔS#), and the Gibbs energy (ΔG#) values, confirmed the enzyme stabilization on the external support surface at temperatures ranging from 50 to 65 °C. These results show promising applications for this new heterogeneous biocatalyst in industrial processes given the high catalytic activity and thermal stability.


Assuntos
Lipase , Oryza , Propilaminas , Silanos , Lipase/metabolismo , Dióxido de Silício , Glutaral , Enzimas Imobilizadas/metabolismo , Termodinâmica , Estabilidade Enzimática
16.
J Fish Dis ; 47(2): e13891, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37990596

RESUMO

Micropterus salmoides rhabdovirus (MSRV) is a significant pathogen that causes high morbidity and mortality in largemouth bass, leading to enormous economic losses for largemouth bass aquaculture in China. The aim of this study was to investigate the efficacy of four disinfectants (potassium permanganate, glutaraldehyde, trichloroisocyanuric acid and povidone iodine) on MSRV, to control the infection and transmission of MSRV in largemouth bass aquaculture. The disinfectants were tested at different concentrations (5, 25, 50, 100 and 500 mg/L) prepared with distilled water for 30 min contact time, and the viral nucleic acid was quantified using qPCR and the infectivity was tested by challenge experiment. Potassium permanganate at 5-500 mg/L, glutaraldehyde at 500 mg/L, trichloroisocyanuric acid at 50-500 mg/L and povidone iodine at 500 mg/L concentration could effectively decrease the virus nucleic acid, and the survival rate of largemouth bass juveniles after challenge experiment increased significantly from 3.7% ± 6.41% to 33.33 ± 11.11% - 100%. Moreover, the minimum effective time of 5 mg/L potassium permanganate was further studied at 2, 5, 10 and 20 min contact time. The viral nucleic acid decreased significantly at 5-20 min exposure time, and the survival rate increased significantly from 7.41% ± 6.41% to 77.78 ± 11.11% - 100%. The median lethal concentration (LC50 ) values of potassium permanganate were 10.64, 6.92 and 3.7 mg/L at 24, 48 and 96 h, respectively. Potassium permanganate could be used for the control of MSRV in the cultivation process; the recommended concentration is 5 mg/L and application time should be less than 24 h. The results could be applied to provide a method to control the infection and transmission of MSRV in water, and improve the health status of largemouth bass.


Assuntos
Bass , Desinfetantes , Doenças dos Peixes , Ácidos Nucleicos , Rhabdoviridae , Animais , Desinfetantes/farmacologia , Glutaral , Permanganato de Potássio , Povidona-Iodo , Doenças dos Peixes/prevenção & controle , Água
17.
Ann Work Expo Health ; 68(1): 97-103, 2024 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-37950922

RESUMO

Glutaraldehyde is a high-efficiency disinfectant that has been included in the protocols of some hospitals for controlling the spread of SARS-CoV-2, together with sodium hypochlorite and quaternary ammonium disinfectants. However, exposure has been poorly studied in workplace settings, despite the association between glutaraldehyde and respiratory diseases and skin conditions in exposed workers. This study evaluated the magnitude of exposure associated with the use of glutaraldehyde in healthcare workers across various work areas of a first level of Hospital-Based Care in Colombia. Workers were classified into similar exposure groups (SEGs) based on work areas and tasks performed, and airborne concentrations of glutaraldehyde were measured in different work areas of each SEG through direct monitoring. The 95th percentile of glutaraldehyde concentrations in all SEGs studied exceeded the TLV-C immediately after use. Cleaning workers and nurses had the highest exposures to glutaraldehyde. Results indicate that workers were overexposed and highlight the need to implement controls to reduce exposure. The high-exposure levels also raise the need to consider glutaraldehyde substitution and adequate use of personal protective equipment (PPE).


Assuntos
Desinfetantes , Exposição Ocupacional , Humanos , Glutaral , Exposição Ocupacional/análise , Desinfetantes/análise , Pessoal de Saúde , Medição de Risco
18.
Tissue Eng Regen Med ; 21(2): 243-260, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37865625

RESUMO

BACKGROUND: Diabetic foot ulcer (DFU) is a major debilitating complication of diabetes. The lack of effective diabetic wound dressings has been a significant problem in DFU management. In this study, we aim to establish a phlorotannin-incorporated nanofibre system and determine its potential in accelerating hyperglycaemic wound healing. METHODS: The effective dose of Ecklonia cava phlorotannins (ECP) for hyperglycaemic wound healing was determined prior to phlorotannin nanofibre fabrication using polyvinyl-alcohol (PVA), polyvinylpyrrolidone (PVP), and ECP. Vapour glutaraldehyde was used for crosslinking of the PVA/PVP nanofibres. The phlorotannin nanofibres were characterised, and their safety and cytocompatibility were validated. Next, the wound healing effect of phlorotannin nanofibres was determined with 2D wound scratch assay, whereas immunofluorescence staining of Collagen-I (Col-I) and Cytokeratin-14 (CK-14) was performed in human dermal fibroblasts (HDF) and human epidermal keratinocytes (HEK), respectively. RESULTS: Our results demonstrated that 0.01 µg/mL ECP significantly improved hyperglycaemic wound healing without compromising cell viability and proliferation. Among all nanofibres, PVA/PVP/0.01 wt% ECP nanofibres exhibited the best hyperglycaemic wound healing effect. They displayed a diameter of 334.7 ± 10.1 nm, a porosity of 40.7 ± 3.3%, and a WVTR of 1718.1 ± 32.3 g/m2/day. Besides, the FTIR spectra and phlorotannin release profile validated the successful vapour glutaraldehyde crosslinking and ECP incorporation. We also demonstrated the potential of phlorotannin nanofibres as a non-cytotoxic wound dressing as they support the viability and proliferation of both HDF and HEK. Furthermore, phlorotannin nanofibres significantly ameliorated the impaired hyperglycaemic wound healing and restored the hyperglycaemic-induced Col-I reduction in HDF. CONCLUSION: Taken together, our findings show that phlorotannin nanofibres have the potential to be used as a diabetic wound dressing.


Assuntos
Diabetes Mellitus , Hiperglicemia , Nanofibras , Humanos , Glutaral/farmacologia , Cicatrização , Diabetes Mellitus/tratamento farmacológico , Colágeno Tipo I
19.
Vet Pathol ; 61(2): 201-206, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37698272

RESUMO

The SARS-CoV-2 pandemic required the immediate need to transfer inactivated tissue from biosafety level (BSL)-3 to BSL-1 areas to enable downstream analytical methods. No validated SARS-CoV-2 inactivation protocols were available for either formaldehyde (FA)-fixed or glutaraldehyde (GA)-fixed tissues. Therefore, representative tissue from ferrets and hamsters was spiked with 2.2 × 106 tissue culture infectious dose 50% per ml (TCID50/ml) SARS-CoV-2 or were obtained from mice experimentally infected with SARS-CoV-2. SARS-CoV-2 inactivation was demonstrated with 4% FA or 5% GA at room temperature for 72 hours by a titer reduction of up to 103.8 TCID50/ml in different animal tissues with a maximum protein content of 100 µg/mg and a thickness of up to 10 mm for FA and 8 mm for GA. Our protocols can be easily adapted for validating the inactivation of other pathogens to allow for the transfer of biological samples from BSL-3 areas to BSL-1 laboratories.


Assuntos
COVID-19 , Animais , Camundongos , Animais de Laboratório , Contenção de Riscos Biológicos/veterinária , COVID-19/veterinária , Furões , Formaldeído/farmacologia , Glutaral/farmacologia , Laboratórios , SARS-CoV-2 , Inativação de Vírus
20.
IEEE Trans Biomed Eng ; 71(3): 916-928, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37801375

RESUMO

OBJECTIVE: Viscoelasticity is mapped by dispersion in shearwave elastography. Incomplete spectral information of shearwaves is therefore used to estimate mechanical stiffness. We propose capturing the "full-waveform-information" of the shear wave spectra to better resolve complex shear modulus µ* (ω). Approach is validated on phantom models, animal tissues, and feasibility demonstrated on human post-delivery placenta. METHODS: We captured robust estimates of µ* in ex-vivo livers subjected to water bath ablation, glutaraldehyde exposure and in the placenta. RESULTS: Complex modulus at 200 Hz is more reflective of tissue stiffness than cross-correlation estimate. Bias increased in phantoms with higher gelatin (G) (0.65: 6% G) and oil (O) (0.58: 6% G and 40% O) concentration, compared to elastic phantoms with low stiffness (0.33: 3% G). Actual tissues also reported higher bias in cross-correlation estimate (rabbit liver: 0.61, porcine liver: 2.20, and human placenta: 0.63). Stiffness is sensitive to ablation temperature, where the overall modulus changed from 3.02 KPa at 16 °C to 2.75 KPa at 56 °C in water bath. With exposure to Glutaraldehyde, the overall modulus increased from 2.37 to 9.03 KPa. Reconstruction errors in the loss modulus decreased by 68% with the power law compared to a Maxwell model in porcine livers with Cole-Cole inverse fitting. CONCLUSION: Omitting Shear wave attenuation leads to bias. Reconstruction of rheological response with a model is sensitive to its architecture and also the framework. SIGNIFICANCE: We use "full spectral information" in ultrasound shear wave elastography to better map µ*(ω) changes in viscoelastic tissues.


Assuntos
Técnicas de Imagem por Elasticidade , Humanos , Animais , Suínos , Coelhos , Glutaral , Ultrassonografia , Técnicas de Imagem por Elasticidade/métodos , Viscosidade , Imagens de Fantasmas , Análise Espectral , Água
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