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BioEssays : News and Reviews in... Jun 2021Biocidal agents such as formaldehyde and glutaraldehyde are able to inactivate several coronaviruses including SARS-CoV-2. In this article, an insight into one mechanism... (Review)
Review
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.
Topics: Animals; Antiviral Agents; Disinfectants; Formaldehyde; Glutaral; Humans; Ketone Bodies; Ketosis; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Virion
PubMed: 33857328
DOI: 10.1002/bies.202000312 -
Brazilian Journal of Cardiovascular... Dec 2019In cases of aortic valve disease, prosthetic valves have been increasingly used for valve replacement, however, there are inherent problems with prostheses, and their... (Review)
Review
In cases of aortic valve disease, prosthetic valves have been increasingly used for valve replacement, however, there are inherent problems with prostheses, and their quality in the so-called Third World countries is lower in comparison to new-generation models, which leads to shorter durability. Recently, transcatheter aortic valve replacement has been explored as a less invasive option for patients with high-risk surgical profile. In this scenario, aortic valve neocuspidization (AVNeo) has emerged as another option, which can be applied to a wide spectrum of aortic valve diseases. Despite the promising results, this procedure is not widely spread among cardiac surgeons yet. Spurred on by the last publications, we went on to write an overview of the current practice of state-of-the-art AVNeo and its results.
Topics: Aortic Valve; Cardiac Valve Annuloplasty; Glutaral; Heart Valve Diseases; Humans; Pericardium; Reoperation; Transplantation, Autologous; Treatment Outcome
PubMed: 31719012
DOI: 10.21470/1678-9741-2019-0304 -
Journal of Diabetes Science and... Jul 2013Clinical management of diabetes must overcome the challenge of in vivo glucose sensors exhibiting lifetimes of only a few days. Limited sensor life originates from... (Review)
Review
Clinical management of diabetes must overcome the challenge of in vivo glucose sensors exhibiting lifetimes of only a few days. Limited sensor life originates from compromised enzyme stability of the sensing enzyme. Sensing enzymes degrade in the presence of low molecular weight materials (LMWM) and hydrogen peroxide in vivo. Sensing enzymes could be made to withstand these degradative effects by (1) stabilizing the microenvironment surrounding the sensing enzyme or (2) improving the structural stability of the sensing enzyme genetically. We review the degradative effect of LMWM and hydrogen peroxide on the sensing enzyme glucose oxidase (GOx). In addition, we examine advances in stabilizing GOx against degradation using hybrid silica gels and genetic engineering of GOx. We conclude molecularly engineered GOx combined with silica-based encapsulation provides an avenue for designing long-term in vivo sensor systems.
Topics: Biosensing Techniques; Cross-Linking Reagents; Drug Compounding; Drug Stability; Enzyme Stability; Enzymes, Immobilized; Glucose Oxidase; Glutaral; Humans
PubMed: 23911187
DOI: 10.1177/193229681300700428 -
Ultrasonics Sonochemistry Jan 2018The hydrogels based on gelatin cross-linked with chitosan (CS) and polyvinyl pyrrolidone (PVP) were synthesized using microwave and ultrasonic coupling technique in this...
The hydrogels based on gelatin cross-linked with chitosan (CS) and polyvinyl pyrrolidone (PVP) were synthesized using microwave and ultrasonic coupling technique in this study. This interpenetrating polymer network (IPN) hydrogels were cross-linked by glutaraldehyde and 1,2-Epoxy-4-vinylcyclohexane. The presence of function groups in the structure of hydrogel films were confirmed using Fourier transform infrared spectroscopy (FT-IR), thermal stability was measured by DSC, and the swelling behaviors were measured gravimetrically in distilled water at the temperature of 27°C. At last, the mechanical properties were tested. The results showed that the hydrogel prepared with microwave and ultrasonic exhibited the highest tensile strength (86.68MPa), comparing with the hydrogel prepared with traditional method and only microwave reactive field. The FT-IR and XRD results showed that the chemical reactions occurred between the NH of chitosan and the COOH of gelatin, and the introduction of ultrasound can improve the reaction rate. The hydrogel film gained in microwave and ultrasonic coupling field has the best combination properties. Therefore, the new microwave-ultrasonic coupling technique is the potential technology to prepare the new hydrogel due to less synthesis time.
Topics: Chemistry Techniques, Synthetic; Chitosan; Epoxy Compounds; Gelatin; Glutaral; Hydrogels; Kinetics; Materials Testing; Microwaves; Povidone; Temperature; Tensile Strength; Ultrasonic Waves; Vinyl Compounds
PubMed: 28946477
DOI: 10.1016/j.ultsonch.2017.08.003 -
Journal of Dentistry Aug 2015This study investigated the transdentinal cytotoxicity of glutahaldehyde-containing solutions/materials on odontoblast-like cells.
OBJECTIVES
This study investigated the transdentinal cytotoxicity of glutahaldehyde-containing solutions/materials on odontoblast-like cells.
METHODS
Dentin discs were adapted to artificial pulp chambers. MDPC-23 cells were seeded on the pulpal side of the discs and the occlusal surface was treated with the following solutions: water, 2% glutaraldehyde (GA), 5% GA, 10% GA, Gluma Comfort Bond+Desensitizer (GCB+De) or Gluma Desensitizer (GDe). Cell viability and morphology were assessed by the Alamar Blue assay and SEM. The eluates were collected and applied on cells seeded in 24-well plates. After 7 or 14 days the total protein (TP) production, alkaline phosphatase activity (ALP) and deposition of mineralized nodules (MN) were evaluated.
RESULTS
Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). GA solutions were not cytotoxic against MDPC-23. GCB+De (85.1%) and GDe (77.2%) reduced cell viability as well as TP production and ALP activity at both periods. After 14 days, GCB+De and GDe groups produced less MN. Affected MDPC-23 presented deformation of the cytoskeleton and reduction of cellular projections.
CONCLUSIONS
The treatment with 2.5%, 5% and 10% GA was not harmful to odontoblast-like cells. Conversely, when GA was combined with other components like HEMA, the final material became cytotoxic.
CLINICAL SIGNIFICANCE
Glutaraldehyde has been used to decrease dentin hypersensitivity. This substance is also capable of preventing resin-dentin bond degradation by cross-linking collagen and MMPs. This study showed that GA might be safe when applied on acid etched dentin. However, when combined with HEMA the product becomes cytotoxic.
Topics: Animals; Cell Line; Cell Survival; Cross-Linking Reagents; Dentin; Glutaral; Mice; Microscopy, Electron, Scanning; Odontoblasts
PubMed: 25985981
DOI: 10.1016/j.jdent.2015.05.004 -
International Journal of Molecular... Sep 2020The context of this study responds to the need for sorbent technology development to address the controlled removal of inorganic sulfate (SO) from saline water and the...
The context of this study responds to the need for sorbent technology development to address the controlled removal of inorganic sulfate (SO) from saline water and the promising potential of chitosan as a carrier system for organosulfates in pharmaceutical and nutraceutical applications. This study aims to address the controlled removal of sulfate using chitosan as a sustainable biopolymer platform, where a modular synthetic approach was used for chitosan bead preparation that displays tunable sulfate uptake. The beads were prepared via phase-inversion synthesis, followed by cross-linking with glutaraldehyde, and impregnation of Ca ions. The sulfate adsorption properties of the beads were studied at pH 5 and variable sulfate levels (50-1000 ppm), where beads with low cross-linking showed moderate sulfate uptake (35 mg/g), while cross-linked beads imbibed with Ca had greater sulfate adsorption (140 mg/g). Bead stability, adsorption properties, and the point-of-zero charge (PZC) from 6.5 to 6.8 were found to depend on the cross-linking ratio and the presence of Ca. The beads were regenerated over multiple adsorption-desorption cycles to demonstrate the favorable uptake properties and bead stability. This study contributes to the development of chitosan-based adsorbent technology via a modular materials design strategy for the controlled removal of sulfate. The results of this study are relevant to diverse pharmaceutical and nutraceutical applications that range from the controlled removal of dextran sulfate from water to the controlled release of chondroitin sulfate.
Topics: Adsorption; Calcium; Carbon-13 Magnetic Resonance Spectroscopy; Chitosan; Cross-Linking Reagents; Glutaral; Hydrogen-Ion Concentration; Kinetics; Microspheres; Photoelectron Spectroscopy; Saline Waters; Sulfates; Thermogravimetry; Water; Water Pollutants, Chemical; Water Purification
PubMed: 32992564
DOI: 10.3390/ijms21197130 -
Acta Biomaterialia Oct 2022Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability,...
Chemically crosslinked acellular bovine pericardium (ABP) has been widely used in clinical practice as bioprostheses. To ensure its consistency and durability, crosslinkers are used in excess, with stability guided by indicators including the hydrothermal denaturation temperature, the enzymatic resistance and the degree of crosslinking. Yet, understanding of the intermolecular structure in collagen fibrils which imparts the intrinsic stability of the ABPs is lacking, and the discrepancies in the stability criteria in varied conditions are poorly explained. In this study, synchrotron small-angle X-ray scattering (SAXS) in combination with thermal and colorimetric methods are employed to investigate the changes in the structure and the stability of ABPs during crosslinking using glutaraldehyde (GA) or 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) at different concentrations. Based on the findings, a mechanism is proposed to explicate the crosslinking effects on collagen structure and the relationship between the structure and each stability indicator. At low crosslinker concentrations, the telopeptidyl-helical linkages are preferred, which cause rearrangements in the intermolecular structure of collagen, and efficiently contribute to its stabilities. Excess crosslinking is revealed by a revert trend in structural changes and the plateauing of the stabilities, assigning to the helical-helical linkages and monovalent bindings. The former would improve thermal stability but not collagenase resistance, whereas the latter have negligible effects. Overall, this study provides a mechanistic understanding of the chemical crosslinking of ABPs, which will contribute to the future development of more efficient and economically viable strategies to produce bioprostheses. STATEMENT OF SIGNIFICANCE: Chemical crosslinking imparts suitable properties to acellular bovine pericardium (ABP) for clinical applications, yet the understanding is lacking on the structure-stability relationship especially under different crosslinking conditions. Structural evidence in this study differentiates the binding sites during crosslinking in collagen fibrils at different crosslinker concentrations, highlighting the excess usage in the conventional crosslinking treatments. The mechanism based on the structure of collagen also successfully explains the dissimilarity in hydrothermal and enzymatic stabilities with varied crosslinking conditions. Future researches focusing on developing biomaterials via chemical crosslinking of ABPs would benefit from this study, for its contribution to the better understanding of the relationship of collagen structure and functions.
Topics: Animals; Biocompatible Materials; Carbodiimides; Cattle; Collagen; Cross-Linking Reagents; Glutaral; Pericardium; Scattering, Small Angle; X-Ray Diffraction
PubMed: 36049624
DOI: 10.1016/j.actbio.2022.08.057 -
Annals of Work Exposures and Health Oct 2022Whilst cleaning agents are commonly used in workplaces and homes, health workers (HWs) are at increased risk of exposure to significantly higher concentrations used to...
BACKGROUND
Whilst cleaning agents are commonly used in workplaces and homes, health workers (HWs) are at increased risk of exposure to significantly higher concentrations used to prevent healthcare-associated infections. Exposure assessment has been challenging partly because many are used simultaneously resulting in complex airborne exposures with various chemicals requiring different sampling techniques. The main objective of this study was to characterize exposures of HWs to various cleaning agents in two tertiary academic hospitals in Southern Africa.
METHODS
A cross-sectional study of HWs was conducted in two tertiary hospitals in South Africa (SAH) and Tanzania (TAH). Exposure assessment involved systematic workplace observations, interviews with key personnel, passive personal environmental sampling for aldehydes (ortho-phthalaldehyde-OPA, glutaraldehyde and formaldehyde), and biomonitoring for chlorhexidine.
RESULTS
Overall, 269 samples were collected from SAH, with 62 (23%) collected from HWs that used OPA on the day of monitoring. OPA was detectable in 6 (2%) of all samples analysed, all of which were collected in the gastrointestinal unit of the SAH. Overall, department, job title, individual HW use of OPA and duration of OPA use were the important predictors of OPA exposure. Formaldehyde was detectable in 103 (38%) samples (GM = 0.0025 ppm; range: <0.0030 to 0.0270). Formaldehyde levels were below the ACGIH TLV-TWA (0.1 ppm). While individual HW use and duration of formaldehyde use were not associated with formaldehyde exposure, working in an ear, nose, and throat ward was positively associated with detectable exposures (P-value = 0.002). Glutaraldehyde was not detected in samples from the SAH. In the preliminary sampling conducted in the TAH, glutaraldehyde was detectable in 8 (73%) of the 11 samples collected (GM = 0.003 ppm; range: <0.002 to 0.028). Glutaraldehyde levels were lower than the ACGIH's TLV-Ceiling Limit of 0.05 ppm. p-chloroaniline was detectable in 13 (4%) of the 336 urine samples (GM = 0.02 ng/ml range: <1.00 to 25.80).
CONCLUSION
The study concluded that detectable exposures to OPA were isolated to certain departments and were dependent on the dedicated use of OPA by the HW being monitored. In contrast, low-level formaldehyde exposures were present throughout the hospital. There is a need for more sensitive exposure assessment techniques for chlorhexidine given its widespread use in the health sector.
Topics: Chlorhexidine; Cross-Sectional Studies; Formaldehyde; Glutaral; Humans; Occupational Exposure; Respiratory Hypersensitivity; Tertiary Care Centers; o-Phthalaldehyde
PubMed: 35674666
DOI: 10.1093/annweh/wxac034 -
Plant Physiology Feb 2017Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this...
Vascular plants transport water under negative pressure without constantly creating gas bubbles that would disable their hydraulic systems. Attempts to replicate this feat in artificial systems almost invariably result in bubble formation, except under highly controlled conditions with pure water and only hydrophilic surfaces present. In theory, conditions in the xylem should favor bubble nucleation even more: there are millions of conduits with at least some hydrophobic surfaces, and xylem sap is saturated or sometimes supersaturated with atmospheric gas and may contain surface-active molecules that can lower surface tension. So how do plants transport water under negative pressure? Here, we show that angiosperm xylem contains abundant hydrophobic surfaces as well as insoluble lipid surfactants, including phospholipids, and proteins, a composition similar to pulmonary surfactants. Lipid surfactants were found in xylem sap and as nanoparticles under transmission electron microscopy in pores of intervessel pit membranes and deposited on vessel wall surfaces. Nanoparticles observed in xylem sap via nanoparticle-tracking analysis included surfactant-coated nanobubbles when examined by freeze-fracture electron microscopy. Based on their fracture behavior, this technique is able to distinguish between dense-core particles, liquid-filled, bilayer-coated vesicles/liposomes, and gas-filled bubbles. Xylem surfactants showed strong surface activity that reduces surface tension to low values when concentrated as they are in pit membrane pores. We hypothesize that xylem surfactants support water transport under negative pressure as explained by the cohesion-tension theory by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below the critical size at which bubbles would expand to form embolisms.
Topics: Biophysical Phenomena; Freeze Fracturing; Glutaral; Magnoliopsida; Models, Biological; Nanoparticles; Osmium Tetroxide; Plant Exudates; Pressure; Surface Tension; Surface-Active Agents; Xylem
PubMed: 27927981
DOI: 10.1104/pp.16.01039 -
Journal of Oral Rehabilitation Jul 2011The effect of biomodification of dentin matrices using collagen cross-linkers, glutaraldehyde (GD) and grape seed extract (GSE), on the reduced modulus of elasticity...
The effect of biomodification of dentin matrices using collagen cross-linkers, glutaraldehyde (GD) and grape seed extract (GSE), on the reduced modulus of elasticity (Er) and nanohardness (H) of the hybrid layer and underlying dentin was investigated at the dentin-resin bonded interface. The coronal dentin of nine molars were exposed and divided into groups: 5% GD, 6·5% GSE and control. Control samples were etched, bonded with Adper Single Bond Plus and Premise composite. GD and GSE were applied for 1 h prior to bonding procedures. After 24 h, samples were sectioned, and resin-dentin beams were either kept in distilled water or exposed to collagenase treatment for 24 h. Nano-indentations were performed at the hybrid layer and underlying dentin. GD and GSE treatment increased the Er and H of resin-dentin interface structures when compared to the control group (P<0·05), particularly the hybrid layer, and may be a promising novel approach to strengthen the dentin-resin bonded interface structures when using these adhesive system and resin-based composite.
Topics: Adhesiveness; Composite Resins; Dental Bonding; Dentin; Dentin-Bonding Agents; Elasticity; Glutaral; Grape Seed Extract; Humans; Materials Testing; Nanotechnology; Surface Properties
PubMed: 21058972
DOI: 10.1111/j.1365-2842.2010.02175.x