Polyvinyl Alcohol Solution Research Articles

Reusing uncured Fiber-reinforced thermoset composite Prepreg waste with water-soluble PVA backing film

One challenge in reusing uncured composite prepreg waste is the removal of the backing film. Ensuring that no backing film remains during the reuse of composite prepreg material is crucial, as the presence of backing film in the laminate can contaminate the part, leading to defects such as delamination. Manual removal of the backing film from the leftover uncured composite prepreg is a labor-intensive task, and ensuring there is no remaining backing film in the prepreg waste can be challenging. To address these issues, the authors implemented a water-soluble polyvinyl alcohol (PVA) film as the backing material for the prepreg, allowing less labor-intensive removal of the PVA backing film by soaking the prepreg in water before reusing. In this study, 20 μm thick 100% PVA film was utilized as backing material for carbon fiber-reinforced thermoset composite prepreg. The performance of the PVA film as a prepreg backing material was assessed, and the process of removing the backing film was demonstrated. To investigate the impact of the backing film removal process on the mechanical properties of the reused prepreg, tensile and double cantilever beam (DCB) tests were conducted. The results indicated that the PVA backing removal and drying processes did not show any significant influence on the tensile properties and interlaminar strength of the reused composite prepreg. Furthermore, this study demonstrated the recycling of the PVA solution used in the backing removal process to produce new PVA film. The application of PVA as a backing film not only simplified the backing film removal for reused prepreg but also established a sustainable closed-loop recycling system for prepreg backing film.

The investigation on targeted micro-surface treatment methods for waste tires recycling in cementitious construction materials

Defects in the interfacial transition zone (ITZ) between recycled tire rubber and cement matrix obstacle to the large-scale application of sustainable rubberized cementitious materials. This paper proposed and evaluated different targeted treatment methods for micro-surface properties enhancement of rubber aggregate by the Polyvinyl Alcohol (PVA), Polyethylene Glycol-200 (PEG), and Hydroxypropyl methylcellulose (HY) polymer solutions through copolymerization and drafting processes. The optimum modification condition was determined through the FT-IR analysis, contact angle, and surface free energy of treated rubber aggregates and the micro-surface morphology and element distribution were analyzed by using ESEM and EDX, respectively. The flexural strength and pore size distribution of steel fiber-reinforced rubberized mortar with relatively high replacing volumes (20%, 40%, and 60%) were evaluated to validate the targeted micro-surface modification efficiency. The surface microstructure and hydrophilic properties of rubber aggregate were significantly improved and the mechanism for enhancing the interface adhesion between rubber and cement matrix was revealed.

Formulation, in vitro and in vivo evaluation of olanzapine nanoparticles dissolving microneedles for transdermal delivery

Olanzapine (OLZ) is classified as a typical antipsychotic drug utilized for the treatment of schizophrenia. Its oral bioavailability is 60% due to its low solubility and pre-systemic metabolism. Hence, the present work aims to formulate and evaluate OLZ nanoparticles dissolving microneedles (MNs) for transdermal delivery to overcome the problems associated with drug administration orally. OLZ nanoparticles were prepared by the nanoprecipitation method. The optimized OLZ nanoparticle formula was utilized for the fabrication of dissolving MNs by loading OLZ nanodispersion into polydimethylsiloxane (PDMS) micromould cavities, followed by casting the polymeric solution of polyvinylpyrrolidone(PVP-K30) and polyvinyl alcohol (PVA) to form MN matrix. The results revealed that the optimized OLZ nanoparticle formula (NP-5) exhibited particle size 115.76±5.45 nm, entrapment efficiency 78.4±5.46, and zeta potential -19.01±1.6 mV. The results of MNs revealed that MN-4 exhibits a high drug content of 98.52%, and ex vivo permeation through rabbit skin exhibited that MN-4 permeates more effectively than a simple patch by approximately 5.16 fold. In vivo pharmacokinetics study revealed that the area under curve AUC 0-∞ of MN-4 was 6054.56±376 ng. h/ml as compared with AUC0-∞ of marketed OLZ tablet was 3975.77±373 ng. h/ml. It can be concluded that the dissolving MN-4 patch is considered a promising formula to overcome the problems associated with drug administration orally and could improve drug bioavailability, in addition to the ease of administering the medication to schizophrenic patients.

Robust, stretchable bioelectronic interfaces for cardiac pacing enabled by interfacial transfer of laser-induced graphene via water-response, nonswellable PVA gels

Implantable cardiac pacemakers are crucial therapeutic tools for managing various cardiac conditions. For effective pacing, electrodes should exhibit flexibility, deformability, biocompatibility, and high conductivity/capacitance. Laser-induced graphene (LIG) shows promise due to its exceptional electrical and electrochemical properties. However, the fragility of LIG and the non-stretchability of polyimide substrates pose challenges when interfacing with the beating heart. Here, we present a simple method for fabricating robust, flexible, and stretchable bioelectronic interfaces by transferring LIG via water-responsive, nonswellable polyvinyl alcohol (PVA) gels. PVA solution penetrates the porous structure of LIG and solidifies into PVA xerogel as the solvent evaporates. The robust PVA xerogel enables the smooth transfer of LIG and prevents stretching of the LIG network during this process, which helps maintain its conductivity. When hydrated, the xerogel becomes a stable, nonswellable hydrogel. This gives the LIG-PVA hydrogel (LIG-PVA-H) composites with excellent conductivity (119.7 ± 4.3Ω sq−1), high stretchability (up to 420%), reliability (cyclic stretch under 15% strain, with ∼ 1-time resistance increase), and good stability in phosphate buffered saline. The LIG-PVA-H composites were used as biointerfaces for electrocardiogram signal recording and electrical pacing on rat hearts ex vivo and in vivo, using commercial setups and a custom-built implantable wireless device. This work expands the application of LIG in bioelectronic interfaces and facilitates the development of electrotherapy for cardiac diseases.

High potency of linalool-zinc oxide nanocomposite as a new agent for cystic echinococcosis treatment.

This current in vitro, ex vivo, and in vivo research aims to evaluate and analyze the linalool-zinc oxide nanocomposite (Lin-ZNP) for treating cystic echinococcosis. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The protoscolicidal effects of Lin-ZNP were tested on hydatid cyst protoscoleces (PTS) in both in vitro and ex vivo by eosin exclusion test. The study also examined the impact on caspase-3 gene expression and the external structure of PTS. The in vivo effect was measured by examining hydatid cysts' quantity, dimensions, and weight in mice intraperitoneally infected with 0.5 mL of PTS solution containing 1,000 PTS. The antioxidant and inflammatory cytokine gene expression levels were examined using real-time PCR. Lin-ZNP significantly (P < 0.001) killed the PTS in both in vitro and ex vivo in a dose- and time-dependent manner. The treated PTS exhibited creases and protrusions as a result of bleb formation and upregulation in the gene expression of caspase-3. Upon treatment with Lin-ZNP, there was a significant (P < 0.001) reduction in the number, diameter, and weight of the hydatid cysts. Treatment with Lin-ZNP nanocomposite led to a significant increase in the expression of antioxidant genes and a notable decrease in oxidative stress markers, and the expression levels of IL-4 and IL-10. Lin-ZNP has the potential to act as a scolicidal agent and demonstrates promise in controlling hydatid cysts in a mouse model, attributed to its antioxidant and anti-inflammatory properties. However, additional studies in clinical trials are needed to confirm the use of Lin-ZNP for treating hydatidosis.

Highly Mechanical Strength, Flexible and Stretchable Wood-Based Elastomers without Chemical Cross-Linking

Wood exhibits a limited elastic deformation capacity under external forces due to its small range of elastic limit, which restricts its widespread use as an elastic material. This study presents the development of a stretchable wood-based elastomer (SWE) that is highly mechanical and flexible, achieved without the use of chemical cross-linking. Balsa wood was utilized as a raw material, which was chemically pretreated to remove the majority of the lignin and create a more abundant pore structure, while exposing the active hydroxyl groups on the cellulose surface. The polyvinyl alcohol (PVA) solution was impregnated into delignified wood, resulting in the formation of a cross-linked structure through multiple freeze–thaw cycles. After eight cycles, the tensile strength in the longitudinal direction reached up to 25.68 MPa with a strain of ~463%. This excellent mechanical strength is superior to that of most wood-based elastomers reported to date. The SWE can also perform complex deformations such as winding and knotting, and SWE soaked in salt solution exhibits excellent sensing characteristics and can be used to detect human finger bending. Stretchable wood-based elastomers with high mechanical strength and toughness have potential future applications in biomedicine, flexible electronics, and other fields.

A transparent superhydrophobic coating on wood-based panel surfaces

ABSTRACT A transparent, environmentally friendly and durable superhydrophobic coating preparation process was developed to effectively isolate water molecules in the air, aiming to reduce the use limitations of the wood-based panel substrate and to realize its improved performance in terms of water resistance, stain resistance and durability. This study employs a coating method to apply a silica sol-modified nanocellulose (CNF) and polyvinyl alcohol (PVA) solution onto a wood-based panel substrate, creating a micro-nano rough structure. Subsequently, the vapor deposition method was employed to functionalize the silanol groups on the coating surface, resulting in the formation of fluorinated alkyl groups and achieving transparent superhydrophobic wood-based panels. The water contact angle measures 152.6°, the rolling angle was 4.5°, and the coating exhibits a light transmittance of 92%. Notably, the superhydrophobicity of the coating persists even after repeated polishing paper abrasion, demonstrating excellent anti-pollution self-cleaning properties. This study is of great significance for the long-term use of wood-based panels indoors and outdoors, as well as their application in complex and high humidity environments.

Development of biocomposite films incorporated with the extract from pitcher associated bacteria for the postharvest protection from fungi.

Pythium aphanidermatum is known to cause diseases likedamping-off, root rot, stem rot and fruit rot in a wide range of plants. Eventhough many chemical methods have been demonstrated to have the potential to manage these diseases, their benefits are being offset equally by the negative side effects. Therefore, the control of Pythium spp. using natural antifungal agents is of immense significance due to its environmental safety. Here, the plant associated microorganisms with antifungal metabolites have significant promises to be explored both as sustainable biocontrol agents and also as active constituents of antifungal materials. Antimicrobial packaging films prepared using such components can have significant applications to meet the requirements to prevent postharvest loss of agricultural produce by inhibiting the fungal growth. Eventhough there are reports on the development of antimicrobial packaging films for such applications, the use of bacterial extracts with antifungal activity for the same is least investigated. Hence, the present study demonstrates the development of biocomposite films prepared using polyvinyl alcohol (PVA) incorporated with the extracts prepared from bacterial isolates (Serratia sp. NhPB1, Kocuria sp. NhPB49, and Pantoea dispersa NhPB54) previously isolated from the pitcher plant. Here, the individual films were prepared by incorporating 1mL of bacterial extract in 40mL of 3% PVA solution and the developed films were then subjected to antifungal activity screening against P. aphanidermatum. The antifungal activity analysis of the films prepared with the incorporation of extracts from Serratia sp. NhPB1, Kocuria sp. NhPB49, and Pantoea dispersa NhPB54 showed remarkable activity against the tested pathogen. The application of biocomposite films on Solanum lycopersicum and Capsicum annuum fruits for its protection from P. aphanidermatum by dip coating method further indicates the promises of developed biocomposite films for active packaging applications.

Synergistic fabrication, characterization, and prospective optoelectronic applications of DES grafted activated charcoal dispersed PVA films

AbstractThis study investigates the synthesis, analysis, and utility of films comprising deep eutectic solvent (DES) grafted activated charcoal (AC) within a polyvinyl alcohol (PVA) matrix for optoelectronic device applications. The fabrication process involves the dispersion of DES functionalization AC into the PVA solution, followed by casting onto substrates with controlled drying. Comprehensive characterization encompassing X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), and impedance spectroscopy which discerns the films microstructure, morphology, conductance, band‐gap, and optical traits. The DES grafted AC infusion with variable concentration has significantly influenced optical absorbance and reduced the band gap indicating efficient charge mobility. Furthermore, the impedance analysis has revealed the electrical conduction of the film to be 1.8 × 10−6 Ω−1 m−1. In summary, the dispersion of DES modified AC in the PVA matrix have converted the insulating PVA to a semiconducting polymeric film with reduced band‐gap and increased absorption, which present a propitious avenue for wide array of optoelectronic devices, such as thin film transistors, photovoltaics, LEDs, photodetectors, and many such applications.

Application of plasma-activated hydrogen peroxide solution synergized with Ag@SiO2 modified polyvinyl alcohol coating for strawberry preservation

To extend the postharvest storage time of strawberries, this study aims to prepare a composite coating using plasma-activated hydrogen peroxide solution (PAH) synergized with nano-Ag@SiO2 by blending method to modify polyvinyl alcohol (PVA) solution. Results showed that the viscosity and the swelling rate of PVA significantly decreased with the addition of Ag@SiO2 at 0.18 %. Meanwhile, the elongation at break and the tensile strength of PVA increased to 0.87 MPa and 214 %. When the addition of Ag@SiO2 was 0.18 % and the composite ratio of PAH to PVA was 1:1, the composites could inactivate the pathogenic bacteria at 2 h. During the storage of strawberries, the initial colony counts on the surface of strawberries could be reduced by about 1 lg CFU/g after coating with the composite film. Moreover, with the extension of the storage time to 7 d, the respiratory intensity, colony counts, and rot index in the strawberries were 65.7 mg/(kg•h), 4.05 log CFU/g, and 38.7 %. Meanwhile, the superoxide dismutase activity and Vc content were 944 U/g and 690 μg/g, respectively. Overall, this study provides ideas and the theoretical basis for applying composite films in fruit preservation.

Linalool-zinc oxide nanocomposite controls Toxoplasma gondii infection through inhibiting inflammation, oxidative stress, and pathogenicity.

The present in vitro and in vivo study aimed to fabricate and characterize linalool-zinc oxide nanoparticles (Lin-ZNP) and evaluate their effectiveness against Toxoplasma gondii infection in terms of inflammation, oxidative stress, and pathogenicity. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The anti-Toxoplasma and cytotoxicity activities of Lin-ZNP were investigated, along with its effects on nitric oxide (NO) production, caspase-3 activity, and pro-inflammatory genes. After treating T. gondii-infected mice with Lin-ZNP for 14 days, the number and size of tissue cysts, antioxidant potential, pro-inflammatory cytokines, and T. gondii pathogenicity-related genes were evaluated by real-time polymerase chain reaction and Western blot analysis. The Lin-ZNP composite showed a reduced tendency with an average size of 105 nm. Lin-ZNP significantly reduced the viability of tachyzoites. The obtained selectivity index higher than 10, indicating high specificity for parasites with low cytotoxicity to normal cells. The Lin-ZNP significantly (p < 0.05) increased the production of NO, caspase-3 activity, and the expression levels of pro-inflammatory genes. Lin-ZNP significantly (p < 0.001) decreased the size and number of tissue cysts and caused a significant reduction in the level of malondialdehyde and a considerable increase (p < 0.001) in antioxidant enzymes and their expression genes. Lin-ZNP significantly downregulated both mRNA and protein expression of the inflammation-related markers associated with the TLRs/NF-κB pathway. The expression levels of the T. gondii pathogenicity-related genes were significantly downregulated (p < 0.05). The recent survey indicated that Lin-ZNP manages T. gondii infection by its antioxidant activity and inhibiting the TLRs/NF-κB pathway without toxicity in mice.

Preparation and properties of acrylate/polyvinyl alcohol self-healing hydrogels based on hydrogen bonds and coordination bonds

Abstract Despite the widespread attention garnered by self-healing hydrogels in various fields, achieving a balance between high mechanical strength and self-healing capability remains a challenge. Particularly, the addition of fillers in the fabrication of spray-coated waterproof materials hinders the movement of molecular chains. Simultaneously, the self-repair of metal ions is hindered by issues such as a prolonged required time and low repair rate. Therefore, we introduce a polyvinyl alcohol (PVA) solution subjected to freeze–thaw cycles into the acrylic acid magnesium/calcium hydrogel system, creating a self-healing hydrogel with an interpenetrating polymer network (IPN). Due to the abundance of hydroxyl groups on the PVA molecular chains, during the freezing process, some PVA chains form microcrystals that do not dissolve upon thawing at room temperature. These microcrystals act as cross-linking points, connecting PVA chains into a 3D network. Consequently, the hydrogel, under the dual effects of hydrogen bonds and coordination bonds, exhibits excellent mechanical properties and the ability to self-heal at room temperature. Furthermore, by adjusting the concentration of the PVA solution, the mechanical properties and healing ability of the hydrogel can be tailored to meet various construction requirements.

Modification of High-Density Polyethylene with a Fibrillar-Porous Structure by Biocompatible Polyvinyl Alcohol via Environmental Crazing.

Polymer/polymer nanocomposites based on high-density polyethylene (HDPE) and biocompatible polyvinyl alcohol (PVA) were prepared by tensile drawing of HDPE in the PVA solutions via environmental crazing. The mechanism of this phenomenon was described. The HDPE/PVA nanocomposites were studied by the methods of scanning electron microscopy, atomic force microscopy, gravimetry, tensile tests, and their composition, properties, and performance were characterized. The content of PVA in the HDPE/PVA nanocomposites (up to 22 wt.%) was controlled by the tensile strain of HDPE and concentration of PVA in the solution. Depending on the content of PVA, the wettability of the HDPE/PVA nanocomposite (hydrophilic-lipophilic balance) could be varied in a broad interval from 45 to 98°. The modification of HDPE by the biocompatible PVA offers a beneficial avenue for practical applications of the HDPE/PVA composites as biomedical materials, packaging and protective materials, modern textile articles, breathable materials, membranes and sorbents, etc.

Preparation and photocatalytic and antibacterial properties of polyvinyl alcohol/chitosan/TiO2@Ag electrospun nanofibers

Polyvinyl alcohol (PVA) is a widely used polymer in the electrospinning technique. It is water-soluble, which limits the application of electrospun PVA matrix. In this study, chitosan (CS) and biosynthesized TiO2@Ag nanoparticles were incorporated into PVA to enhance its antibacterial properties and photocatalysis. The PVA/CS/TiO2@Ag nanofiber mat was prepared using the electrospinning method with a voltage of 20 kV, a needle-collector distance of 15 cm, and a flow rate of 0.5 mL.h−1. The concentrations of the PVA and CS solutions were 10% and 2%, respectively. The TiO2@Ag nanoparticles were synthesized using AgNO3 solution, TiO2 nanoparticles as precursors, and Cleistocalyx operculatus leaf extract as a reducing agent. The morphology and structure of the PVA/CS/TiO2@Ag nanofiber mat were analyzed using scanning electron microscopy and infrared spectroscopy. The PVA/CS/TiO2@Ag nanofibers exhibited an average fibril diameter of 116.4 nm. Additionally, the antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as the photocatalytic properties of these mats, were assessed. The results indicated that the addition of CS and TiO2@Ag led to changes in the hydrophilic properties and antibacterial efficacy of PVA. The inhibition zones of the PVA/CS/TiO2@Ag nanofiber mat against E. coli and S. aureus were measured at 5 and 4 mm, respectively. The water contact angle of PVA/CS/TiO2@Ag nanofiber mat showed a significant increase. The PVA/CS/TiO2@Ag nanofibers were able to degrade 94.56 ± 0.57% and 98.17 ± 0.11% of methylene blue dye under sunlight irradiation after 10 and 20 min of exposure, respectively. These findings suggest that the PVA/CS/TiO2@Ag nanofiber mat has the potential for applications in the textile industry or medicinal field as antibacterial and photocatalytic coatings.

Development of porous hydroxyapatite/PVA/gelatin/alginate hybrid flexible scaffolds with improved mechanical properties for bone tissue engineering

Porous scaffolds based on gelatin and hydroxyapatite particles (HAp) are promising for applications in bone tissue engineering and regenerative medicine. However, they are not ideal for stress and shock protection due to low compressive strength, brittleness, and poor toughness. Herein, we developed porous hybrid scaffolds by combining multiple components into a single bone scaffold, including hydroxyapatite nanoparticles (HAp NPs), alginate, polyvinyl alcohol (PVA), and gelatin with different gelatin/PVA composition ratios. HAp NPs were synthesized in situ in PVA solution and scaffolds were fabricated using a freeze-drying method. The results showed good physicochemical properties of the scaffolds: formation of pure HAp NPs phase, high porosity, large pore sizes, large swelling capacity depending on varying gelatin/PVA ratios, as well as a long-term degradation rate up to 28 days. The porous scaffolds exhibited compressive strength close to the cancellous bone with stress-strain behavior exhibiting three-stage flexible behavior indicating improved fracture resistance with an energy absorbing capability up to 1.9 MJ/m3. The scaffolds have a yield strength of 70–403 kPa, a compressive strength at 65 % strain of 0.96–1.80 MPa, a nonporous elastic modulus of 10.44–12.40 GPa, and a densification strain of approximately 0.92 %. This work develops three-dimensional (3D) porous hybrid bone scaffolds with mechanical strength within the minimum compressive strength of cancellous bone and mechanical energy absorption capacity favor for cancellous bone repair, bone tissue engineering, and regenerative medicine applications.

Z-scheme heterojunction g-C3N4-TiO2 reinforced chitosan/poly(vinyl alcohol) film: Efficient and recyclable for fruit packaging

Nanoparticles-loaded bio-based polymers have emerged as a sustainable substitute to traditional oil-based packaging materials, addressing the challenges of limited recyclability and significant environmental impact. However, the functionality and efficiency of nanoparticles have a significant impact on the application of bio-based composite films. Herein, graphitic carbon nitride (g-C3N4) and titanium dioxide (TiO2) coupled photocatalyst (g-C3N4-TiO2) was prepared by one-step calcination and introduced into chitosan (CS) and polyvinyl alcohol (PVA) solution to fabricate g-C3N4-TiO2/CS/PVA green renewable composite film via solution casting method. The results demonstrated the successful preparation of a Z-scheme heterojunction g-C3N4-TiO2 with exceptional photocatalytic activity. Furthermore, the incorporation of heterojunction enhanced mechanical properties, water barrier, and ultraviolet (UV) resistance properties of the fresh-keeping film. The g-C3N4-TiO2/CS/PVA composite film exhibited superior photocatalytic antibacterial preservation efficacy on strawberries under LED light, with a prolonged preservation time of up to 120 h, when compared to other films such as polyethylene (PE), CS/PVA, g-C3N4/CS/PVA, and TiO2/CS/PVA. In addition, the composite film has good recyclability and renewability. This work is expected to have great potential for low-cost fruit preservation and sustainable packaging, which also contributes to environmental protection.

Preparation and Application of Degradable Lignin/Poly (Vinyl Alcohol) Polymers as Urea Slow-Release Coating Materials.

The massive amount of water-soluble urea used leads to nutrient loss and environmental pollution in both water and soil. The aim of this study was to develop a novel lignin-based slow-release envelope material that has essential nitrogen and sulfur elements for plants. After the amination reaction with a hydrolysate of yak hair keratin, the coating formulation was obtained by adding different loadings (2, 5, 8, 14 wt%) of aminated lignin (AL) to 5% polyvinyl alcohol (PVA) solution. These formulations were cast into films and characterized for their structure, thermal stability, and mechanical and physicochemical properties. The results showed that the PVA-AL (8%) formulation had good physical and chemical properties in terms of water absorption and mechanical properties, and it showed good degradation in soil with 51% weight loss after 45 days. It is suitable for use as a coating material for fertilizers. Through high-pressure spraying technology, enveloped urea particles with a PVA-AL (8%) solution were obtained, which showed good morphology and slow-release performance. Compared with urea, the highest urea release was only 96.4% after 30 days, conforming to Higuchi model, Ritger-Peppas model, and second-order dynamic model. The continuous nitrogen supply of PVA-AL coated urea to Brassica napus was verified by potting experiments. Therefore, the lignin-based composite can be used as a coating material to produce a new slow-release nitrogen fertilizer for sustainable crop production.

A Novel Method to Enhance the Mechanical Properties of Polyacrylonitrile Nanofiber Mats: An Experimental and Numerical Investigation.

This study addresses the challenge of enhancing the transverse mechanical properties of oriented polyacrylonitrile (PAN) nanofibers, which are known for their excellent longitudinal tensile strength, without significantly compromising their inherent porosity, which is essential for effective filtration. This study explores the effects of doping PAN nanofiber composites with varying concentrations of polyvinyl alcohol (PVA) (0.5%, 1%, and 2%), introduced into the PAN matrix via a dip-coating method. This approach ensured a random distribution of PVA within the nanofiber mat, aiming to leverage the synergistic interactions between PAN fibers and PVA to improve the composite's overall performance. This synergy is primarily manifested in the structural and functional augmentation of the PAN nanofiber mats through localized PVA agglomerations, thin films between fibers, and coatings on the fibers themselves. Comprehensive evaluation techniques were employed, including scanning electron microscopy (SEM) for morphological insights; transverse and longitudinal mechanical testing; a thermogravimetric analysis (TGA) for thermal stability; and differential scanning calorimetry (DSC) for thermal behavior analyses. Additionally, a finite element method (FEM) analysis was conducted on a numerical simulation of the composite. Using our novel method, the results demonstrated that a minimal concentration of the PVA solution effectively preserved the porosity of the PAN matrix while significantly enhancing its mechanical strength. Moreover, the numerical simulations showed strong agreement with the experimental results, validating the effectiveness of PVA doping in enhancing the mechanical properties of PAN nanofiber mats without sacrificing their functional porosity.

Synthesis and characterization of mupirocin-LDH/PVA nanofibrous composite as a dual-carrier drug release system

Nowadays, nanofibrous structures based on organic and inorganic materials are considered a drug delivery system for the controlled release of antibiotics and other antibacterial agents. The main goal of this research is a combination of the special properties of nanofibrous structure and Mupirocin-loaded Layered double hydroxide (LDH) to obtain a dual-carrier drug release system to provide long term antibacterial properties in wound healing process. Regards, unloaded layered double hydroxide (LDH) and Mupirocin-loaded LDH, which were synthesized by co-precipitation method, were added to Polyvinyl alcohol (PVA) solution in different mass ratio and electrospun using different processing conditions. The physico-chemical characterizations were performed using SEM, FTIR and tensile strength tests. The biological properties of the fabricated nanocomposites were evaluated using antibacterial test and in vitro cell culturing followed by MTT assay. The SEM results showed a bead-less and uniform morphology of nanofibrous composite containing Mupirocin(2.3 wt%)-LDH(15 wt%)/PVA with an average fiber diameter of about 270 ± 58 nm. According to the release study, the maximum release of the mupirocin drug was about 54 % in the first 6 h. The antibiogram analysis exhibited good antibacterial activity of mupirocin-loaded nanocomposite against both bacteria, especially gram-positive one. Finally, MTT assay approved the biocompatibility of the mupirocin-loaded nanocomposite. Overall, the produced nanofibrous composites would be a promising dual-carrier system for controlled release of antibiotic.

Double-Layer Asymmetric Porous Mesh with Dynamic Mechanical Support Properties Enables Efficient Single-Stage Repair of Contaminated Abdominal Wall Defect.

Contamination tolerance and long-term mechanical support are the two critical properties of meshes for contaminated abdominal wall defect repair. However, biological meshes with excellent pollution tolerance fail to provide bio-adaptive long-term mechanical support due to their rapid degradation. Here, a novel double-layer asymmetric porous mesh (SIS/PVA-EXO) is designed by simple and efficient in situ freeze-thaw of sticky polyvinyl alcohol (PVA) solution on the loosely porous surface of small intestinal submucosal decellularized matrix (SIS), which can successfully repair the contaminated abdominal wall defect with bio-adaptive dynamic mechanical support through only single-stage surgery. The exosome-loaded degradable loosely porous SIS layer accelerates the tissue healing; meanwhile, the exosome-loaded densely porous PVA layer can maintain long-term mechanical support without any abdominal adhesion. In addition, the tensile strength and strain at break of SIS/PVA-EXO mesh change gradually from 0.37MPa and 210% to 0.10MPa and 385% with the degradation of SIS layer. This unique performance can dynamically adapt to the variable mechanical demands during different periods of contaminated abdominal wall reconstruction. As a result, this SIS/PVA-EXO mesh shows an attractive prospect in the treatment of contaminated abdominal wall defect without recurrence by integrating local immune regulation, tissue remodeling, and dynamic mechanical supporting.