Preparation of polyvinyl alcohol/chitosan nanofibrous films incorporating graphene oxide and lanthanum chloride by electrospinning method for potential photothermal and chemical synergistic antibacterial applications in wound dressings

Enhancing production efficiency: Preparation, optimization, and characterization of polyvinyl alcohol/chitosan antibacterial hydrogels

Biocompatible and degradable hydrogels have garnered interest in wound dressings due to their ability to absorb biological fluids with properties resembling natural tissues. In this study, polyvinyl alcohol (PVA)-chitosan (CS)-cefazolin (Cef) hydrogels were prepared using the solution casting method. To optimize hydrogel properties (swelling and degradation), essential process parameters, including PVA concentration, CS concentration, blend ratio of PVA/CS, and glutaraldehyde (GA) percentage, were investigated using response surface methodology (RSM). Experiments were performed at different pH levels (7.4, 5.8, 9.2) related to skin pH in various healing phases. Drug release studies showed that Cefazolin release was highest at pH 9.2, making it highly beneficial for treating infections in high-pH wounds. At pH levels of 7.4 and 5.8, the release was moderate to low, indicating a controlled release profile. Cytotoxicity tests revealed higher cell viability in treated samples compared to controls over five days. Results indicated that CS and PVA concentrations had a significant impact on the response variables, with increased CS amounts leading to enhanced swelling and degradation. The optimized hydrogel is characterized by FTIR, XRD, TGA, FESEM, EDX, AFM, porosity, gel content, mechanical properties, and antibacterial activity. Morphological evaluation confirmed suitable surface roughness for cell growth and wound healing, highlighting its potential as a wound dressing. The apparent porosity and gel content of the hydrogel were 74.90 % and 95.74 ± 0.6 %, respectively. Mechanical tests showed tensile strength, elastic modulus, and elongation at break at 8.75 MPa, 0.824 MPa, and 106.87 %, respectively. The antibacterial activity against Escherichia coli, Staphylococcus, and Salmonella was reported as 24.4 ± 0.5 mm, 37 ± 1 mm, and 32 ± 1.5 mm, respectively. These results and optimized process parameters highlight its potential for industrial wound care applications.

Chitosan-based materials for food preservation: Enhancing shelf life and safety through sustainable nanoparticles and films

This review provides a comprehensive overview of chitosan-based films and nanoparticles loaded with bioactive compounds, focusing on their role in extending the shelf life of meat products. Chitosan, a biodegradable and non-toxic polysaccharide, is valued for its antimicrobial, antioxidant, and bioactive properties, positioning it as a promising alternative to synthetic preservatives and packaging. Chitosan nanoparticles, often prepared by ionic gelation, offer high encapsulation efficiency for bioactive compounds, such as essential oils, to control microbial growth and oxidative processes. While chitosan-based films serve as effective edible coatings, they face challenges in mechanical strength and water vapor permeability. The incorporation of and natural compounds enhances these properties, supporting real-world use. Additionally, chitosan films with pH indicators have emerged as innovative tools for monitoring food freshness. Despite these advances, further research is required to improve mechanical and barrier properties, enable large-scale scale industrial production, and explore new bioactive compounds.

Enhanced antibacterial activity of Al-doped CuS incorporated PVA nanofiber films: Photothermal and photodynamic perspectives

Antibiotic resistance poses a major challenge to modern healthcare and requires innovative microbial control strategies. Here, we report a novel method for integrating aluminum-doped copper sulfide (CuS@Al) microspheres into polyvinyl alcohol (PVA) matrix by electrospinning to obtain multifunctional nanofiber membranes with both photothermal and photodynamic antimicrobial properties (PVA-CuS@Al). Based on the rational design of Al doping to form structural defects on CuS microspheres, the light absorption and reactive oxygen species (ROS) were significantly enhanced. Under near-infrared (NIR) irradiation (808 nm, 2.0 W/cm²), PVA-CuS@Al with 5 wt% CuS@Al achieved rapid temperature rise from 25 °C to 181 °C within 15 s, and complete inactivation of Escherichia coli and Staphylococcus aureus was achieved within 10 min by photothermal ablation. In addition, under simulated sunlight, the membrane effectively generates ROS, achieving 100 % bacterial inhibition through photodynamic effects. The performance of the material goes beyond previous studies by combining dual antibacterial mechanisms on a single platform, reducing the required additive concentration (3 wt% CuS@Al), while maintaining biocompatibility and blood compatibility. This work introduces the development strategy of a new generation of antibacterial wound dressing with high efficiency and low cytotoxicity.

Dual phage-incorporated electrospun polyvinyl alcohol-eudragit nanofiber matrix for rapid healing of diabetic wound infected by Pseudomonas aeruginosa and Staphylococcus aureus

Diabetic wound healing remains a healthcare challenge due to co-occurring multidrug-resistant (MDR) bacterial infections and the constraints associated with sustained drug delivery. Here, we integrate two new species of phages designated as PseuPha1 and RuSa1 respectively lysing multiple clinical MDR strains of P. aeruginosa and S. aureus into a novel polyvinyl alcohol-eudragit (PVA-EU†) nanofiber matrix through electrospinning for rapid diabetic wound healing. PVA-EU† evaluated for characteristic changes that occurred due to electrospinning and subjected to elution, stability and antibacterial assays. The biocompatibility and wound healing ability of PVA-EU† were assessed through mouse fibroblast cell line NIH3T3, followed by validation through diabetic mice excision wound co-infected with P. aeruginosa and S. aureus. The electrospinning resulted in the incorporation of ~ 75% active phages at PVA-EU†, which were stable at 25 °C for 30 days and at 4 °C for 90 days. PVA-EU† showed sustained release of phages for 18 h and confirmed to be detrimental to both mono- and mixed-cultures of target pathogens. The antibacterial activity of PVA-EU† remained unaltered in the presence of high amounts of glucose, whereas alkaline pH promoted the activity. The matrix exerted no cytotoxicity on NIH3T3, but showed significant (p < 0.0001) wound healing in vitro and the process was rapid as validated through a diabetic mice model. The sustained release, quick wound closure, declined abundance of target MDR bacteria in situ and histopathological signs of recovery corroborated the therapeutic efficacy of PVA-EU†. Taken together, our data signify the potential application of PVA-EU† in the rapid treatment of diabetic wounds without the aid of antibiotics.

In-vitro investigation of chitosan/polyvinyl alcohol/TiO2 composite membranes for wound regeneration

Bacterial infections significantly delay the physiological wound healing process and can cause further damage to the wound region. In the current work, we aim to design titanium dioxide nanoparticles (TiO2 NPs) incorporated with chitosan (Chi) and poly (vinyl alcohol) (PVA) film using the casting method and to study their potential for faster wound healing. The prepared TiO2 NPs were analyzed for physicochemical properties, and TEM results showed an average particle size of 39.6 nm. The nanocomposite films were scrutinized by FTIR, XRD, and TGA analyses. The effective incorporation of the nanoparticles and their uniform dispersion within the Chi/PVA matrix was confirmed through SEM analysis. The composite films exhibited excellent hydrophilic properties (64.3°), along with favorable swelling and degradation rates, and mechanical properties similar to native skin tissue, ensuring comfortable interaction with wound beds. The better hemocompatibility, with an erythrocyte lysis percentage of 3.52 %, further supports the wound healing properties of these films. Additionally, composite films possess excellent antibacterial activity against wound pathogens such as B. subtilis and E. coli. Furthermore, an in vitro wound closure rate of 92.3 % at 48 h was observed for the TiO2 incorporated film (CPT3) using fibroblast HIH3T3 cells. The results suggest that it could be a promising biomaterial for wound healing application.

Advances in Electrospun Nanofiber Membranes for Dermatological Applications: A Review

In recent years, a wide variety of high-performance and versatile nanofiber membranes have been successfully created using different electrospinning methods. As vehicles for medication, they have been receiving more attention because of their exceptional antibacterial characteristics and ability to heal wounds, resulting in improved drug delivery and release. This quality makes them an appealing choice for treating various skin conditions like wounds, fungal infections, skin discoloration disorders, dermatitis, and skin cancer. This article offers comprehensive information on the electrospinning procedure, the categorization of nanofiber membranes, and their use in dermatology. Additionally, it delves into successful case studies, showcasing the utilization of nanofiber membranes in the field of skin diseases to promote their substantial advancement.

Systematic review of the osteogenic effect of rare earth nanomaterials and the underlying mechanisms

Rare earth nanomaterials (RE NMs), which are based on rare earth elements, have emerged as remarkable biomaterials for use in bone regeneration. The effects of RE NMs on osteogenesis, such as promoting the osteogenic differentiation of mesenchymal stem cells, have been investigated. However, the contributions of the properties of RE NMs to bone regeneration and their interactions with various cell types during osteogenesis have not been reviewed. Here, we review the crucial roles of the physicochemical and biological properties of RE NMs and focus on their osteogenic mechanisms. RE NMs directly promote the proliferation, adhesion, migration, and osteogenic differentiation of mesenchymal stem cells. They also increase collagen secretion and mineralization to accelerate osteogenesis. Furthermore, RE NMs inhibit osteoclast formation and regulate the immune environment by modulating macrophages and promote angiogenesis by inducing hypoxia in endothelial cells. These effects create a microenvironment that is conducive to bone formation. This review will help researchers overcome current limitations to take full advantage of the osteogenic benefits of RE NMs and will suggest a potential approach for further osteogenesis research.

Optimizing Wound Healing: Examining the Influence of Biopolymers Through a Comprehensive Review of Nanohydrogel-Embedded Nanoparticles in Advancing Regenerative Medicine

Nanohydrogel wound healing refers to the use of nanotechnology-based hydrogel materials to promote the healing of wounds. Hydrogel dressings are made up of a three-dimensional network of hydrophilic polymers that can absorb and retain large amounts of water or other fluids. Nanohydrogels take this concept further by incorporating nanoscale particles or structures into the hydrogel matrix. These nanoparticles can be made of various materials, such as silver, zinc oxide, or nanoparticles derived from natural substances like chitosan. The inclusion of nanoparticles can provide additional properties and benefits to the hydrogel dressings. Nanohydrogels can be designed to release bioactive substances, such as growth factors or drugs, in a controlled manner. This allows for targeted delivery of therapeutics to the wound site, promoting healing and reducing inflammation. Nanoparticles can reinforce the structure of hydrogels, improving their mechanical strength and stability. Nanohydrogels often incorporate antimicrobial nanoparticles, such as silver or zinc oxide. These nanoparticles have shown effective antimicrobial activity against a wide range of bacteria, fungi, and other pathogens. By incorporating them into hydrogel dressings, nanohydrogels can help prevent or reduce the risk of infection in wounds. Nanohydrogels can be designed to encapsulate and release bioactive substances, such as growth factors, peptides, or drugs, in a controlled and sustained manner. This targeted delivery of therapeutic agents promotes wound healing by facilitating cell proliferation, reducing inflammation, and supporting tissue regeneration. The unique properties of nanohydrogels, including their ability to maintain a moist environment and deliver bioactive agents, can help accelerate the wound healing process. By creating an optimal environment for cell growth and tissue repair, nanohydrogels can promote faster and more efficient healing of wounds.