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Scientific Reports Aug 2023Toxic dyes in water bodies and bacterial pathogens pose serious global challenges to human health and the environment. Zinc oxide nanoparticles (ZnO NPs) demonstrate...
Toxic dyes in water bodies and bacterial pathogens pose serious global challenges to human health and the environment. Zinc oxide nanoparticles (ZnO NPs) demonstrate remarkable photocatalytic and antibacterial potency against reactive dyes and bacterial strains. In this work, PVP-ZnO NPs have been prepared via the co-precipitation method using polyvinylpyrrolidone (PVP) as a surfactant. The NPs' microstructure and morphology were studied using X-ray diffraction (XRD), having a size of 22.13 nm. High-resolution transmission electron microscope (HR-TEM) and field emission scanning electron microscopy (FESEM) analysis showed spherical-shaped PVP-ZnO NPs with sizer ranging from 20 to 30 nm. Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the hybrid nature of the NPs, and UV-Vis spectroscopy showed an absorption peak at 367 nm. The PVP-ZnO NPs exhibited high photocatalytic activity, achieving 88% and nearly 95% degradation of reactive red-141 azo dye with 10 mg and 20 mg catalyst dosages, respectively. The antibacterial properties of the NPs were demonstrated against Escherichia coli and Bacillus subtilis, with inhibition zones of 24 mm and 20 mm, respectively. These findings suggest that PVP-ZnO NPs can be effectively used for water treatment, targeting both dye and pathogenic contaminants.
Topics: Humans; Povidone; Zinc Oxide; Spectroscopy, Fourier Transform Infrared; Anti-Infective Agents; Anti-Bacterial Agents; Coloring Agents; Escherichia coli; Nanoparticles
PubMed: 37620547
DOI: 10.1038/s41598-023-41103-7 -
Materials (Basel, Switzerland) Jan 2024Nowadays, due to the increasing number of diseases and injuries related to bone tissue, there is an acute problem of creating a material that could be incorporated into...
Nowadays, due to the increasing number of diseases and injuries related to bone tissue, there is an acute problem of creating a material that could be incorporated into the bone tissue structure and contribute to accelerated bone regeneration. Such materials can be represented by a polymeric matrix that holds the material in the bone and an inorganic component that can be incorporated into the bone structure and promote accelerated bone regeneration. Therefore, in this work we investigated polyvinyl alcohol-based composite cryogels containing an in situ deposited inorganic filler, hydroxyapatite. The freezing temperature was varied during the synthesis process. The composition of the components was determined by infrared spectroscopy and the phase composition by X-ray phase analysis, from which it was found that the main phase of the composite is hydroxyapatite and that the particle size decreases with increasing freezing temperature. The elemental composition of the surface is dominated by carbon, oxygen, phosphorus and calcium; no impurities of other elements not typical for polyvinyl alcohol/ hydroxyapatite cryogels were found. Higher mechanical properties and melting points were observed at -15 °C. Cryogenic treatment parameters did not affect cell viability; however, cell viability was above 80% in all samples.
PubMed: 38255572
DOI: 10.3390/ma17020403 -
Molecules (Basel, Switzerland) Sep 2023To enhance the mechanical strength and cell adhesion of alginate hydrogel, making it satisfy the requirements of an ideal tissue engineering scaffold, the grafting of...
To enhance the mechanical strength and cell adhesion of alginate hydrogel, making it satisfy the requirements of an ideal tissue engineering scaffold, the grafting of Arg-Gly-Asp (RGD) polypeptide sequence onto the alginate molecular chain was conducted by oxidation of sodium periodate and subsequent reduction amination of 2-methylpyridine borane complex (2-PBC) to synthesize alginate dialdehyde grafted RGD derivatives (ADA-RGD) with good cellular affinity. The interpenetrating network (IPN) composite hydrogels of alginate/polyvinyl alcohol/cellulose nanocrystals (ALG/PVA/CNCs) were fabricated through a physical mixture of ion cross-linking of sodium alginate (SA) with hydroxyapatite/D-glucono-δ-lactone (HAP/GDL), and physical cross-linking of polyvinyl alcohol (PVA) by a freezing/thawing method, using cellulose nanocrystals (CNCs) as the reinforcement agent. The effects of the addition of CNCs and different contents of PVA on the morphology, thermal stability, mechanical properties, swelling, biodegradability, and cell compatibility of the IPN composite hydrogels were investigated, and the effect of RGD grafting on the biological properties of the IPN composite hydrogels was also studied. The resultant IPN ALG/PVA/CNCs composite hydrogels exhibited good pore structure and regular 3D morphology, whose pore size and porosity could be regulated by adjusting PVA content and the addition of CNCs. By increasing the PVA content, the number of physical cross-linking points in PVA increased, resulting in greater stress support for the IPN composite hydrogels of ALG/PVA/CNCs and consequently improving their mechanical characteristics. The creation of the IPN ALG/PVA/CNCs composite hydrogels' physical cross-linking network through intramolecular or intermolecular hydrogen bonding led to improved thermal resistance and reduced swelling and biodegradation rate. Conversely, the ADA-RGD/PVA/CNCs IPN composite hydrogels exhibited a quicker degradation rate, attributed to the elimination of ADA-RGD by alkali. The results of the in vitro cytocompatibility showed that ALG/0.5PVA/0.3%CNCs and ADA-RGD/PVA/0.3%CNCs composite hydrogels showed better proliferative activity in comparison with other composite hydrogels, while ALG/PVA/0.3%CNCs and ADA-RGD/PVA/0.3%CNCs composite hydrogels displayed obvious proliferation effects, indicating that PVA, CNCs, and ADA-RGD with good biocompatibility were conducive to cell proliferation and differentiation for the IPN composite hydrogels.
Topics: Polyvinyl Alcohol; Hydrogels; Alginates; Oligopeptides; Cellulose; Nanoparticles
PubMed: 37764467
DOI: 10.3390/molecules28186692 -
Food Science & Nutrition Feb 2024The aim of the present study was to fabricate, characterize, and evaluate the in vitro antimicrobial and antioxidant properties of zein/polyvinyl alcohol (ZN/PVA)...
Characteristics, antimicrobial capacity, and antioxidant potential of electrospun zein/polyvinyl alcohol nanofibers containing thymoquinone and electrosprayed resveratrol nanoparticles.
The aim of the present study was to fabricate, characterize, and evaluate the in vitro antimicrobial and antioxidant properties of zein/polyvinyl alcohol (ZN/PVA) nanofibers containing 2% and 4% of thymoquinone (TQ), either alone or in combination with electrosprayed ZN nanoparticles containing 1% and 2% of resveratrol (RS). According to scanning electron microscopy analysis, the diameter of nanofibers and nanoparticles increased with increasing TQ and RS concentrations, respectively. The molecular interaction between ZN or PVA polymers and TQ or RS was confirmed by Fourier transform infrared spectroscopy. Thermogravimetric analysis showed that the thermal stability of nanofibers did not change with the addition of TQ and RS. Moreover, incorporation of TQ in nanofibers along with RS nanoparticles increased their antibacterial and free radical scavenging activities based on broth dilution and DPPH methods, respectively ( ≤ .05). O157:H7 (as a Gram-negative pathogenic bacteria) was more resistant to all treatments than (as a Gram-positive pathogenic bacteria). In addition, the combined use of TQ in nanofibers and RS nanoparticles had antagonistic antibacterial and synergistic antioxidant effects. The best results were obtained with ZN/PVA nanofiber containing 4% TQ and electrosprayed with 2% RS nanoparticles ( ≤ .05). According to the results of the present study, biodegradable ZN/PVA nanofiber containing TQ and electrosprayed with RS nanoparticles can be used as a novel active packaging material in the food industry.
PubMed: 38370090
DOI: 10.1002/fsn3.3816 -
BMC Oral Health Jul 2023Polyvinyl ether siloxane (PVES) possesses ideal characteristics for making precise and accurate dental impressions. PVES dimensional stability owes to its better... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
Polyvinyl ether siloxane (PVES) possesses ideal characteristics for making precise and accurate dental impressions. PVES dimensional stability owes to its better polymeric properties derived from its parent materials poly ethers and polyvinyl siloxanes. As recommended use of chemical disinfecting agents is getting more popular, there is a growing concern associated with the effect of disinfectants on PVES dimensional stability. This study was aimed to understand the PVES behavior when subjected to chemical disinfectants.
MATERIALS AND METHODOLOGY
The data was collected from research studies retrieved from Google Scholar, Scopus, and PubMed using MeSH terms of keywords "vinyl polyether siloxane AND Disinfection" or (Vinyl polyether siloxane OR polyvinyl siloxane ether OR PVES) AND (disinfectant OR disinfection)" without any restriction to publication date. The PRISMA (Preferred Reporting Items for Systemic Review and Meta-Analysis) directions were observed during the data collection, screening of studies, and meta-analysis. The primary data were retrieved, and batch exported from databases using Harzing's Publish or Perish software; primary analysis was performed in Microsoft Excel, while statistical analysis for effect size, two-tailed p-values, and heterogeneity among studies was performed using Meta Essentials. The effect size was calculated using Hedge's g values at the 95% confidence level using the random-effects model. Heterogeneity among studies was measured using the Cochrane Q and I.
RESULTS AND CONCLUSION
Dental impressions made from the PVES elastomeric impression materials showed no significant changes in dimensional stability. Immersion in the chemical disinfectant for 10 min was associated with clinically irrelevant changes in the dimensions of the PVES impressions. Disinfection with sodium hypochlorite was associated with clinically significant changes in dimensions, with a two-tailed p-value of 0.049. Disinfection with 2-2.5% glutaraldehyde solution was not associated with any significant dimensional variability.
Topics: Humans; Disinfectants; Disinfection; Ether; Ethers; Ethyl Ethers; Polyvinyls; Siloxanes
PubMed: 37430254
DOI: 10.1186/s12903-023-03168-8 -
International Journal of Pharmaceutics Jul 2023Through 3D printing (3DP), many parameters of solid oral dosage forms can be customised, allowing for truly personalised medicine in a way that traditional...
Through 3D printing (3DP), many parameters of solid oral dosage forms can be customised, allowing for truly personalised medicine in a way that traditional pharmaceutical manufacturing would struggle to achieve. One of the many options for customisation involves dose titration, allowing for gradual weaning of a medication at dose intervals smaller than what is available commercially. In this study we demonstrate the high accuracy and precision of 3DP dose titration of caffeine, selected due to its global prevalence as a behavioural drug and well-known titration-dependent adverse reactions in humans. This was achieved using a simple filament base of polyvinyl alcohol, glycerol, and starch, utilising hot melt extrusion coupled with fused deposition modelling 3DP. Tablets containing 25 mg, 50 mg, and 100 mg doses of caffeine were successfully printed with drug content in the accepted range prescribed for conventional tablets (90 - 110%), and excellent precision whereby the weights of all doses showed a relative standard deviation of no more than 3%. Importantly, these results proved 3D printed tablets to be far superior to splitting a commercially available caffeine tablet. Additional assessment of filament and tablet samples were reviewed by differential scanning calorimetry, thermogravimetric analysis, HPLC, and scanning electron microscopy, showing no evidence of degradation of caffeine or the raw materials, with smooth and consistent filament extrusion. Upon dissolution, all tablets achieved greater than 70% release between 50 and 60 min, showing a predictable rapid release profile regardless of dose. The outcomes of this study highlight the benefits that dose titration with 3DP can offer, especially to more commonly prescribed medications that can have even more harmful withdrawal-induced adverse reactions.
Topics: Humans; Caffeine; Tablets; Polyvinyl Alcohol; Hot Melt Extrusion Technology; Printing, Three-Dimensional; Drug Liberation; Technology, Pharmaceutical
PubMed: 37315638
DOI: 10.1016/j.ijpharm.2023.123132 -
Membranes Jun 2023Flame-resistant polymer composites were prepared based on polyvinyl alcohol (PVA) as a polymer matrix and a polyphosphonate as flame retardant. Oxalic acid was used as...
Flame-resistant polymer composites were prepared based on polyvinyl alcohol (PVA) as a polymer matrix and a polyphosphonate as flame retardant. Oxalic acid was used as crosslinking agent. LiClO, BaTiO, and graphene oxide were also incorporated into PVA matrix to increase the ionic conductivity. The obtained film composites were investigated by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and microscale combustion tests. Incorporating fire retardant (PFRV), BaTiO, and graphene oxide (GO) into a material results in increased resistance to fire when compared to the control sample. A thermogravimetric analysis revealed that, as a general trend, the presence of PFRV and BaTiO nanoparticles enhances the residue quantity at a temperature of 700 °C from 7.9 wt% to 23.6 wt%. Their dielectric properties were evaluated with Broad Band Dielectric Spectroscopy. The electrical conductivity of the samples was determined and discussed in relation to the LiClO content. The electrical properties, including permittivity and conductivity, are being enhanced by the use of LiClO. Additionally, a relaxation peak has been observed in the dielectric losses at frequencies exceeding 103 Hz. The electrical properties, including permittivity and conductivity, are being enhanced by the use of LiClO. Additionally, a relaxation peak has been observed in the dielectric losses at frequencies exceeding 103 Hz. Out of the various composites tested, the composite containing 35 wt% of LiClO exhibits the highest alternating current (AC) conductivity, with a measured value of 2.46 × 10 S/m. Taking into consideration all the aspects discussed, these improved composites are intended for utilization in the manufacturing of Li-Ion batteries.
PubMed: 37505004
DOI: 10.3390/membranes13070636 -
Marine Pollution Bulletin Oct 2023Microplastics in aquatic environments is a growing concern, particularly due to the leaching of chemical additives such as plasticisers. To develop comprehensive...
Microplastics in aquatic environments is a growing concern, particularly due to the leaching of chemical additives such as plasticisers. To develop comprehensive environmental risk assessments (ERAs) of high-concern polymers and plasticisers, an understanding of their leachability is required. This work investigated diethylhexyl phthalate (DEHP) and bisphenol A (BPA) leaching from polyvinyl chloride (PVC) microplastics (average diameter = 191 μm) under simulated marine conditions. Leaching behaviours were quantified using gel permeation chromatography (GPC) and thermal gravimetric analysis (TGA), and the polymer's physiochemical properties analysed using differential scanning calorimetry (DSC), Fourier Transform-Infrared Spectroscopy (FT-IR) and optical microscopy. Experimental data were fitted to a diffusion and boundary layer model, which found that BPA leaching was temperature-dependent (diffusion-limited), whereas DEHP leaching was controlled by surface rinsing. Model predictions also highlighted the importance of microplastic size on leaching dynamics. These data contribute towards greater accuracy in ERAs of microplastics, with implications for water quality and waste management, including decommissioning of plastic infrastructure.
PubMed: 37690404
DOI: 10.1016/j.marpolbul.2023.115392 -
PloS One 2023The pore structure characteristics and thermal conductivity of foamed concrete (FC) reinforced with glass fibers (GF), polyvinyl alcohol fibers (PVAF) and polypropylene...
The pore structure characteristics and thermal conductivity of foamed concrete (FC) reinforced with glass fibers (GF), polyvinyl alcohol fibers (PVAF) and polypropylene fibers (PPF) were investigated experimentally in this article. Firstly, GF, PVAF or PPF with different mass fractions (0%, 1%, 1.5% and 2%) were added to the Portland cement, fly ash and plant protein foaming agent to prepare the FC. Then, SEM tests, dry density tests, porosity tests, and thermal conductivity tests were carried out on FRFC. Later, the adhesion of GF, PVAF and FFF with different mass fractions to the cementitious base was investigated by SEM images of FRFC. The pore size distribution, shape factor and porosity of FRFC were analyzed using Photoshop software and Image Pro Plus (IPP) software. Finally, the effects of different mass fractions and lengths of three types of fibers on the thermal conductivity of FRFC were discussed. The results indicated that proper fiber mass fraction can play a role of refining small pores and separating large pores, improving the structural compactness, reducing the pore collapse phenomenon and optimizing the pore structure of FRFC. The three types of fibers can promote the optimization of cellular roundness and increase the proportion of pores with diameters below 400 μm. The FC with larger porosity had smaller dry density. As the fiber mass fraction increased, the thermal conductivity performed a phenomenon of first decrease and then increase. The three types of fibers with 1% mass fraction achieved relatively low thermal conductivity. Compared with the FC without fibers, the thermal conductivities of GF reinforced FC, PVAF reinforced FC and PPF reinforced FC with 1% mass fraction were decreased by 20.73%, 18.23% and 7.00%, respectively.
Topics: Thermal Conductivity; Coal Ash; Plant Proteins; Polyvinyl Alcohol; Porosity
PubMed: 37418476
DOI: 10.1371/journal.pone.0287690 -
Polymers Jul 2023Dehumidifying air via refrigerant cooling method consumes a tremendous amount of energy. Independent humidity control systems using desiccants have been introduced to...
Dehumidifying air via refrigerant cooling method consumes a tremendous amount of energy. Independent humidity control systems using desiccants have been introduced to improve energy efficiency. This research aimed to find an alternative to the commonly used solid desiccant, silica gel, which has weak physical adsorption properties. It also aimed to overcome the limitation of liquid desiccants that may affect indoor air quality and cause corrosion. This study reports on the synthesis of poly(vinyl alcohol-co-acrylic acid), P(VA-AA), through solution polymerisation by hydrolysing poly(vinyl acetate-co-acrylic acid), P(VAc-AA). This viable copolymer was then incorporated with graphene oxide (GO) at different concentrations (0 wt.%, 0.5 wt.%, 2 wt.% and 5 wt.%) to enhance the adsorption-desorption process. The samples were tested for their ability to adsorb moisture at different levels of relative humidity (RH) and their capability to maintain optimum sorption capacity over 10 repeated cycles. The nanocomposite film with 2% GO, P(VA-AA)/GO2, exhibited the highest moisture sorption capacity of 0.2449 g/g for 60-90% RH at 298.15 K, compared to its pristine copolymer, which could only adsorb 0.0150 g/g moisture. The nanocomposite desiccant demonstrated stable cycling stability and superior desorption in the temperature range of 318.15-338.15 K, with up to 88% moisture desorption.
PubMed: 37514388
DOI: 10.3390/polym15142998