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The outstanding biodegradability, biocompatibility, affordability, and renewability of polylactic acid have made it a prominent biomaterial. Herein, an innovative, easy, and eco-friendly technique is used to prepare sodium polylactate (SP)-based nanofibers. Solution blowing spinning (SBS) was used to create fibrous mats of SP and polyvinyl alcohol (PVA). SBS's SP nanfibers were crosslinked using an aqueous solution of calcium chloride to produce moisture-resistant calcium polylactate nanofibrous spun mats. Both of UV-visible absorption spectra and transmission electron microscopy were utilized to study the produced zinc oxide (ZnO) nanoparticles (NPs) to indicate a diameter of around 15-23 nm with a high intensity absorption intensity at 370 nm. New polylactate copolymer was synthesized and characterized by infrared and NMR spectroscopic techniques. In order to prepare SP/PVA/ZnO nanocomposite nanofibers, various ZnO ratios were used. The morphologies of the composite nanofibers were investigated by infrared spectroscopy (FTIR), energy-dispersive X-ray analyzer, and scanning electron microscopy. The cytotoxicity tests of the prepared mat were studied by conducting experiments with L-929 cells at various time intervals. The prepared composite SP/PVA/ZnO nanofibers were subjected to cytotoxicity tests to determine their cytocompatibility. Results showed that those with ZnO concentrations between 0.5% and 2% were found to be less harmful than those with higher concentrations. A variety of bacterial species, including Bacillus pumilus and Staphylococcus aureus, as well as Klebseilla pneumoniae and Escherichia coli, were used to test the antibacterial properties of SP/PVA/ZnO spun mats. The ZnO NPs integrated in the SP/PVA fibrous mats were responsible for their antibacterial properties. After finding the appropriate concentration of ZnO that is least harmful while yet giving a satisfactory antibacterial activity, this biomaterial might be perfect for wound dressing applications. HIGHLIGHTS: New eco-friendly biodegradable sodium polylactate (SP) copolymer was synthesized. Zinc oxide nanoparticles (ZnO NPs) with a diameter of 15-23 nm were prepared. High antibacterial SP/PVA/ZnO fibers were prepared by solution blowing spinning. SP/PVA/ZnO nanofibers (180-220 nm) with various ratios of ZnO were presented. Cytotoxicity results showed that the cell viability decreases with increasing ZnO.

The skin is the largest organ in the human body and its physical integrity must be maintained for body homeostasis and to prevent the entry of pathogenic microorganisms. Sodium alginate (SA) and polyvinyl alcohol (PVA) are two polymers widely used in films for wound dressing applications. Furthermore, blends between SA and PVA improve physical, mechanical and biological properties of the final wound healing material when compared to the individual polymers. Different drugs have been incorporated into SA/PVA-based films to improve wound healing activity. It is noteworthy that SA/PVA films can be crosslinked with Ca

Additive manufacturing advancements contribute considerably to several fields, and its use in the medical field is gaining attention due to its easily customizable option (patient-specific), low cost, and fast turnout time in developing drug delivery and diagnostic tools. Here, wereport the fabrication of a microneedle (MN) platform using a stereolithography 3D printer, varying the 3D printing angle and aspect ratio (2:1, 3:1, 4:1). The optimal printing angle was30, resulting in needle tip and base diameters of 50 µm and 330 µm, and heights of 550/850/1180 µm. Polyvinyl alcohol (PVA) MNs produced with varying levofloxacin concentrations showed variability of 4% in tip and 3% base diameters and 15% in height compared to the 3D-printed MNs. Geometry B wasused to produce levofloxacin-loaded PVA MNs and tested against Klebsiella pneumoniae colony biofilms. Levofloxacin wasreleased gradually, as assessed by spectrofluorimetry. The MIC of levofloxacin against the K. pneumoniae clinical isolate was4 µg/mL, but this concentration wasinsufficient to cause any effect on K. pneumoniae biofilms. Only concentrations 32 µg/mL werestatistically different compared to the unloaded MNs. 3D printing is an attractive solution to produce molds for fabricating biopolymeric MNs for topical drug delivery., S.S. acknowledges funding by FCT through the individual scientific employment program contract (2020.03171.CEECIND). The radius was corrected to diameter on June 12, 2023., info:eu-repo/semantics/publishedVersion

Skin is a protective barrier that can protect against environmental influences and renew itself. However, in some cases, this regenerative property is lost, and this causes delays in wound healing. Wound healing is a complex and long-lasting phase. Any bacterial infection during the wound healing process delays wound healing. The therapeutic efficacy can be increased by using nanocarrier drug delivery systems to the target tissue with modern wound dressings. Controlled nano drug delivery systems increase the therapeutic efficacy in the treatment of diseases and provide a faster recovery process. In this study, amoxicillin (AMX) and rifampicin (RIF) were loaded into the bismuth ferrite (BFO) particles which were synthesized with the co-precipitation method. Then, these drug-loaded BFO particles (0.075 %) were added separately to 13 % polyvinyl alcohol (PVA) solution and the solutions were printed three-dimensionally to obtain three dimensional scaffolds. With these designed scaffolds, it is aimed to reduce the risk of inflammation in wound tissues and increase therapeutic efficacy with controlled release. The SEM images proved that homogeneous pore distributions could be achieved with these combinations. The tensile test results showed that drug-loaded BFO addition increased the mechanical strength of the 13 % PVA scaffold. The biocompatibility test results demonstrated that the highest viability values of the human adipose tissue-derived mesenchymal stem cells were obtained for AMX-added 13 % PVA scaffolds.

Tomographic volumetric bioprinting (VBP) enables fast photofabrication of cell-laden hydrogel constructs in one step, addressing the limitations of conventional layer-by-layer additive manufacturing. However, existing biomaterials that fulfill the physicochemical requirements of VBP are limited to gelatin-based photoresins of high polymer concentrations. The printed microenvironments are predominantly static and stiff, lacking sufficient capacity to support 3D cell growth. Here a dynamic resin based on thiol-ene photo-clickable polyvinyl alcohol (PVA) and thermo-sensitive sacrificial gelatin for fast VBP of functional ultrasoft cell-laden hydrogel constructs within 7-15 s is reported. Using gelatin allows VBP of permissive hydrogels with low PVA contents of 1.5%, providing a stress-relaxing environment for fast cell spreading, 3D osteogenic differentiation of embedded human mesenchymal stem cells and matrix mineralization. Additionally, site-specific immobilization of molecules-of-interest inside a PVA hydrogel is achieved by 3D tomographic thiol-ene photopatterning. This technique may enable spatiotemporal control of cell-material interactions and guides in vitro tissue formation using programmed cell-friendly light. Altogether, this study introduces a synthetic dynamic photoresin enabling fast VBP of functional ultrasoft hydrogel constructs with well-defined physicochemical properties and high efficiency., Advanced Functional Materials, 33 (20), ISSN:1616-3028, ISSN:1616-301X

This review provides a comprehensive overview on applications, preparation methods, and most notably the performance efficiency of polyvinyl alcohol (PVA)-based membranes for filtration of aqueous environments. Incorporation of PVA into the membrane matrix significantly enhances such characteristics as antifouling and antibacterial properties as well as hydrophilicity and permeability in the water and wastewater filtrations. Contribution of different PVA-based modular membranes for water purification targets via a comparative review on previous researches is the main theme in this work. Alongside with the focused topic, some basic theories and principals of blend and composite polymer films as well as polymer fibers are debated before the main discussions. This review will ultimately facilitate further development of PVA membranes for the future investigations.

Developing radical emission at ambient conditions is a challenging task since radical species are unstable in air. In the present work, we overcome this challenge by coassembling a series of tricarbonyl-substituted benzene molecules with polyvinyl alcohol (PVA). The strong hydrogen bonds between the guest dopants and the PVA host matrix protect the free radicals of carbonyl compounds after light irradiation, leading to strong solid state free radical emission. Changing temperature and peripheral functional groups of the tricarbonyl-substituted benzenes can influence the intensity of the radical emission. Quantum-chemical calculations predict that such free radical fluorescence originates from anti-Kasha D2 →D0 vertical emission by the anion radicals. The photoinduced radical emission by the tricarbonyl-substituted benzenes was successfully utilized for information encryption application. Ministry of Education (MOE) This research was sponsored by the Shanghai Pujiang Program of China (No.20PJ1400500) and the Singapore Academic Research Fund (No.RT12/19 and MOE-T2EP10120-0003). G.B. thanks the support by the Swedish Research Council (No.2020-04600). The computations were enabled by the Swedish National Infrastructure for Computing (SNIC)at the High Performance Computing Center North (HPC2N) partially funded by the Swedish Research Council through grant agreement no. 2018-05973

Bioabsorbable arterial grafts can potentially improve patency and neovessel formation; however, their application in clinical settings has not been realized. In this study, we developed bioabsorbable gradient sheets based on silk fibroin (SF) and polyvinyl alcohol (PVA) with a core-shell nanofibrous structure. This gradient sheet was expected to promote vascular remodeling while we maintained its physical properties and a gradual degrading process from the luminal surface. ESP was conducted at various flow rates for SF and PVA to achieve the multilayer gradient structure. Furthermore, the elasticity of the gradient sheet could be increased by increasing the PVA flow rate; however, this reduced the tensile strength of the core-shell fibers. Notably, the physical properties of the gradient sheet did not degrade even after 7 days of immersion in a phosphate buffer saline solution, which indicates that the structure could maintain its structural integrity while resisting arterial pressure. In vitro experiments revealed that the number of endothelial cells attached to the SF/PVA sheet was notably higher than that on the cell-culture dish. The gradient sheets were implanted in rat abdominal aortas and explanted after 14 days to confirm acute-phase patency and vascular remodeling. The gradient sheets constructed with SF composed of polyurethane and PVA improved the ease of handling of the material, and these sheets resulted in a favorable vascular remodeling outcome. Our results strongly suggest that the SF/PVA-based gradient sheets described in this study can serve as a novel design for bioabsorbable arterial grafts upon further modifications.

Glycyrrhiza glabra L. root essential oil (GGEO) has well‐known antimicrobial and therapeutic features. In this study, a new antimicrobial carboxymethyl cellulose–polyvinyl alcohol (CMC‐PVA) binary film was developed using GGEO as an active compound. The effects of various concentrations of GGEO (0.25%, 0.50%, and 0.75%) were scrutinized on the physicochemical and antibacterial properties of composites. It was discovered that GGEO significantly reduced the composite ultimate tensile strength from 17.01 to 3.86 MPa. Further, by increasing the concentration of GGEO to 0.75%, the water vapor permeability and moisture content increased to 13.61 × 10−9 g/m s−1 Pa−1 and 41.06%, respectively. The results indicated that the active films possessed good inhibitory effects against the gram‐positive bacteria (L. monocytogenes and Staphylococcus aureus) and were less powerful against gram‐negative bacteria (Escherichia coli and S. typhimurium). Finally, the results highlighted that GGEO can act as an excellent antimicrobial agent in combination with CMC‐PVA composite., Glycyrrhiza glabra L. root essential oil (GGEO) has well‐known antimicrobial and therapeutic features. In this study, a new antimicrobial carboxymethyl cellulose–polyvinyl alcohol (CMC‐PVA) binary film was developed using GGEO as an active compound.

Mucoadhesive buccal patch is a promising dosage form for a successful oral drug delivery, which provides unique advantages for various applications such as treatment of periodontal disease and postdental surgery disorders. The aim of this study is to synthesize a novel multifunctional mucoadhesive buccal patch in a multilayer reservoir design for therapeutic applications. The patches were fabricated through simultaneous electrospinning of chitosan/poly(vinylalcohol) (PVA)/ibuprofen and electrospraying of phenylalanine amino acid nanotubes (PhNTs) containing metronidazole into the electrospun mats through a layer-by-layer process. An electrospun poly(caprolactone) (PCL) was used as an impermeable backing layer to protect the mucoadhesive component from tongue movement and drug loss. Buccal patches were characterized using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) and also evaluated in terms of physicomechanical parameters such as pH, weight, thickness, tensile strength, folding endurance, and mucoadhesive properties. The swelling index of the patches was examined with respect to the PVA/chitosan ratio. The effect of genipin addition to the electrospinning solution was also studied on mucoadhesive and swelling properties. The cell viability of buccal patches was assessed by methylthiazolydiphenyl-tetrazolium bromide test on L929 fibroblast cell line. The patch with an optimal amount of mucoadhesive polymers (PVA/chitosan 80:20) and crosslinking agent (0.05 g) indicated an ideal hemostatic activity along with antibacterial properties against Streptococcus mutans bacteria. The synthesized multifunctional mucoadhesive patch with a novel composition and design has a great potential for oral therapeutic applications.

An ecofriendly and low-cost film composed by cassava starch, polyvinyl alcohol, and sericin blend (CS-PVA-SS) was synthesized, characterized, and applied as a novel support for Botryosphaeria ribis EC-01 lipase immobilization by enzyme-film-enzyme adsorption. Film revealed thickness between 230 and 309 μm and higher flexibility and malleability in comparison with film without SS. Based on p-nitrophenyl palmitate hydrolysis reaction, the activity retention of immobilized lipase was 987%. For optimal conditions, the yield in ethyl oleate was 95% for immobilized enzyme. Maximum yield was obtained at 49°C, molar ratio oleic acid:ethanol of 1:3, 1.25 g lipase film or 50 U (1.03 ± 0.03 mg protein) and 30 h. Even after seven cycles of use, immobilized lipase showed 52% reduction in ester yield. Biodegradable and biorenewable film is a promising material as a support to immobilize lipases and application in biocatalysis.

Electrospun nanofibers have gained much attention for enzyme immobilization due to their high surface-to-volume ratio. In this study, urease was immobilized on chitosan/poly(vinyl alcohol) (PVA) nanofibers by both adsorption and crosslinking methods. In order to obtain nanofibers with more desirable properties, solutions with different ratios of chitosan and PVA were electrospun and crosslinked using glutaraldehyde. Comparing SEM images of the nanofibers, before and after immersing them in phosphate buffer, it was shown that higher chitosan content leads to more stable fibers. So, the solution with the chitosan to PVA ratio of 40:60 was used for enzyme immobilization. Then, the effects of initial protein concentration, temperature, incubation time, and method of immobilization were investigated to reach the highest enzyme activity. Under similar immobilization conditions, covalently immobilized urease showed higher activity, compared to uncrosslinked immobilized enzyme. Besides, it retained 30% of its initial activity after 10 times usage. So, this method was chosen for further investigation. Not only the activity of the immobilized enzyme was much higher than the free enzyme in a wide range of pH and temperature, but also stability of the immobilized enzyme was improved. Immobilized urease was then used to remove thiourea which is a toxic compound. Findings indicated 60% hydrolysis of initial thiourea in 12 h. In conclusion, the findings showed that chitosan/PVA nanofibers are suitable candidates for the immobilization of urease.

Recently, luminescent organic crystals have been widely studied as new optoelectronic materials. However, corrosion and dissolution of organic crystals by solvents have always been a great challenge for the application of organic crystals in various fields. In this work, we propose a general method of fabricating a solvent resistant coating to prevent organic crystals from being corroded or dissolved by organic solvents. The coatings involved layer-by-layer assembly of poly(diallyldimethylammonium) (PDDA) and poly(styrenesulfonate) (PSS) onto crystals, followed by immersing the coated crystals into polyvinyl alcohol (PVA) aqueous solutions for 2 minutes. The coated crystals can remain intact over 24 h in common organic solvents without being damaged and even insoluble in dichloromethane for 5 days. Moreover, the thin and transparent coatings have little effect on the optical properties of crystals which still have excellent optical waveguide performance with the coatings. The results not only are important for the application of organic crystals under extreme conditions, but also provide guidance for the combination between organic optoelectronic materials and polymer materials.

Three-dimensional (3D) culturing mimics the heterogeneous cellular conditions of the in vivo tumor microenvironment compared to 2D monolayer-cultured cells and 3D cultures of established cancer cell lines (sphere culture) or patient-derived cancer cells (organoid culture) are frequently used for cancer research or drug screening and evaluation. To establish more cost and time-efficient 3D culture methods for cancer cell lines, we supplemented sphere culture medium with polyvinyl alcohol (PVA) and found that 3D sphere cultures of breast and pancreatic cancer cell lines were significantly increased. Mechanistically, we found that PVA prevented cell death and promoted cellular proliferation while maintaining levels of stemness-related gene expression. Furthermore, we showed that polyvinyl formal resin (PVF) 3D scaffolds made by cross-linked PVA can function in serum-free, long-term 3D cultures to support maintenance of sphere- or tumor-like cell masses for diverse cancer cell types. Taken together, we demonstrate the effectiveness of PVA and PVF in human cancer cell line culture protocols.

Although polyvinyl alcohol and sodium alginate gel (PVA/SA) cell immobilization technology has been successfully applied in anaerobic ammonium oxidation (anammox) processes, there is no comprehensive evaluation of the PVA:SA ratio in PVA/SA gel beads. Therefore, to determine the optimal PVA:SA ratio, the nitrogen removal performance and structure of PVA/SA anammox gel beads under different PVA:SA ratios were studied through batch experiments. The results suggested that cell immobilization technology could significantly improve the nitrogen removal rate (NRR). PVA concentration was positively correlated with the proportion of -macropore in the gel beads but negatively correlated with mechanical strength. Despite having poor mechanical strength, PVA/SA (12%/2%) gel beads had the highest NRR owing to the increased pore size and were experimentally determined to be the most suitable concentration of immobilized carrier. UASB reactor tests showed that compared with anammox granular sludge, the response time of anammox PVA/SA (12%/2%) beads to increased nitrogen load was shorter and the specific anammox activity was higher. Candidatus "Jettenia" was the dominant bacterium in anammox gel beads, accounting for 37.96% of the community. This study provides a reference for preparing PVA/SA cell immobilization. PRACTITIONER POINTS: Increasing the concentration of PVA can reduce the apoptosis of microorganisms during the gel process. The macropore of PVA/SA beads increased with the increase of the PVA:SA ratio. This study provides a reference for preparing PVA/SA gel beads immobilized anammox bacteria.

Nowadays, the problem of oil spill and organic solvent pollution has become more and more serious, and developing a green and efficient treatment method has become a research hotspot. Herein, the preparation of porous super‐hydrophobic aerogel by directional freezing with cellulose nanofibre (CNF) as the base material, polyvinyl alcohol (PVA) as the cross‐linking agent and montmorillonite (MMT) as the modifier and filler, followed by hydrophobic treatment with chemical vapour deposition is reported. The prepared composite aerogel presented three‐dimensional inter‐perforation network structure, low density (26.52 mg⋅cm−3), high porosity (96.1 %) and good hydrophobicity (water contact angle of 140°). Notably, the composite aerogel has a good adsorption effect on different oils and organic solutions, and its adsorption capacity can reach 40–68 times of its initial weight. After complete adsorption, the aerogel could be easily collected. More importantly, the composite aerogel had high strength, whose compressive stress at 70 % strain reached 0.15 MPa and could bear over 1290 times its weight without deformation after 2 weeks. A new, green, simple and efficient absorbent for the adsorption of oils and organic solvents is provided.

The design of novel wound dressings for chronic wound treatment is still of great importance. One of the promising approaches is application of mesenchymal stem cells (MSCs), immobilized on a flexible polymer film, for healing. In this study, blended films based on polyvinyl alcohol (PVA) and pectin with different component ratio have been prepared by solution casting method and evaluated. Physicochemical properties of the formed PVA/pectin films, including their morphology, wettability, swelling, stability, mechanical characteristics, have been studied. We demonstrated that the surface of PVA/pectin films could be modified by ultraviolet or dielectric barrier discharge plasma exposure. After both ultraviolet and plasma treatment, the hydrophilicity of PVA/pectin films increased. It has been shown that additional crosslinking of PVA/pectin films with glutaraldehyde resulted in reinforcement of their structure. MSCs were cultured on neat and modified PVA/pectin samples to evaluate the effects of film characteristics and composition on cell behavior. It has been determined that MSCs effectively adhered to glutaraldehyde-crosslinked PVA/pectin films and formed on them the monolayer culture of fibroblast-like cells. The additional modification of PVA/pectin films with collagen resulted in enhancement of MSCs adhesion. Our results show that the obtained PVA/pectin films with adhered MSCs can be suggested for potential application as a part of novel complex wound dressings.