Tendon-inspired hybrid hydrogel based on polyvinyl alcohol and gallic acid-lysozyme for promoting wound closure and healing

Nano hydrogel with bacterial nanocellulose and bitter almond oil nanoemulsions for enhanced wound healing: In-vivo and in-vitro characterization

Biocompatibility, good mechanical properties, infection prevention, and anti-inflammatory are the requirements of an ideal wound dressing for the care and treatment of skin wounds. In this study, the nanohydrogels as wound dressing, were fabricated by bacterial nanocellulose (BNC), polyvinyl alcohol (PVA), and gellan gum. Bitter almond oil nanoemulsion (BAO-NE) was made with ultrasonic force and incorporated into the nanohydrogels in concentrations of 2, 4, and 6 %. The mechanical and physicochemical analyses such as tensile strength (TS), elongation at break (EB), swelling, water vapor transmission rate (WVTR), degradation, FTIR-ATR, and SEM, and anti-inflammatory, antibacterial, etc. properties of the nanohydrogels were investigated. Also, the wound healing ability was evaluated by in-vivo analyses. The molecular analyses of the expression of genes related to collagen production and inflammation were performed. Increasing BAO-NE concentration enhanced anti-inflammatory and antibacterial activities against Gram-negative and Gram-positive bacteria (P < 0.05). The in-vivo study presented the healing role of nanohydrogels in rat wounds. Real-time PCR results confirmed the anti-inflammatory and healing effects of the films at molecular levels. All the results testify to the promising properties of the fabricated nanohydrogels as a potential wound dressing.

Polyvinyl alcohol/chitosan quaternary ammonium salt composite hydrogel with directional macroporous structure for photothermal synergistic antibacterial and wound healing promotion

After skin tissue trauma, wound infections caused by bacteria posed a great threat to skin repair. However, resistance to antibiotics, the current treatment of choice for bacterial infections, greatly affected the efficiency of anti-infection and wound healing. Therefore, there has been a critical need for the development of novel antimicrobial materials and advanced therapeutic methods to aid in skin repair. In this paper, rGO-PDA@ZIF-8 nanofillers were prepared by coating graphene oxide (GO) with dopamine (DA), followed by in situ growth of zeolite imidazolate framework-8 (ZIF-8). Using polyvinyl alcohol (PVA) and chitosan quaternary ammonium salt (CS) as matrix materials, along with polyethylene glycol (PEG) as a pore-forming agent, and rGO-PDA@ZIF-8 as an antimicrobial nano-filler, we successfully prepared rGO-PDA@ZIF-8/PVA/CS composite hydrogels with a directional macroporous structure using bidirectional freezing method and phase separation technique. This hydrogel exhibited excellent mechanical properties, good solubility and water retention capabilities. In addition, the hydrogel demonstrated excellent biocompatibility. Most notably, it not only exhibited excellent bactericidal effect against E. coli and S. aureus (99.1 % and 99.0 %, respectively) under the synergistic effect of intrinsic antibacterial activity and photothermal antibacterial, but also exhibited the ability to promote wound healing, making it a promising candidate for wound healing applications.

Designing a bi-layer multifunctional hydrogel patch based on polyvinyl alcohol, quaternized chitosan and gallic acid for abdominal wall defect repair

In abdominal wall defect repair, surgical site infection (SSI) remains the primary cause of failure, while complications like visceral adhesions present significant challenges following patch implantation. We designed a Janus multifunctional hydrogel patch (JMP) with antibacterial, anti-inflammatory, and anti-adhesive properties. The patch comprises two distinct layers: a pro-healing layer and an anti-adhesion layer. The pro-healing layer was created by a simple mixture of polyvinyl alcohol (PVA), quaternized chitosan (QCS), and gallic acid (GA), crosslinked to form PVA/QCS/GA (PQG) hydrogels through GA's self-assembly effect and hydrogen bonding. Additionally, the PVA anti-adhesive layer was constructed using a drying-assisted salting method, providing a smooth and dense physical barrier to prevent visceral adhesion while offering essential mechanical support to the abdominal wall. The hydrogel patch demonstrates widely adjustable mechanical properties, exceptional biocompatibility, and potent antimicrobial properties, along with a sustained and stable release of antioxidants. In rat models of skin and abdominal wall defects, the JMP effectively promoted tissue healing by controlling infection, inhibiting inflammation, stimulating neovascularization, and successfully preventing the formation of visceral adhesions. These compelling results highlight the JMP's potential to improve the success rate of abdominal wall defect repair and reduce surgical complications.

Polyphenol-sodium alginate supramolecular injectable hydrogel with antibacterial and anti-inflammatory capabilities for infected wound healing

Injectable hydrogel has attracted appealing attention for skin wound treatment. Although multifunctional injectable hydrogels can be prepared by introducing bioactive ingredients with antibacterial and anti-inflammatory capabilities, their preparation remains complicated. Herein, a polyphenol-based supramolecular injectable hydrogel (PBSIH) based on polyphenol gallic acid and biological macromolecule sodium alginate is developed as a wound dressing to accelerate wound healing. We show that such PBSIH can be rapidly formed within 15 s by mixing the sodium alginate and gallic acid solutions based on the hydrogen bonding and hydrophobic interactions. The PBSIH shows excellent cytocompatibility, antibacterial, and antioxidant properties, which enhance infected wound healing by inhibiting bacterial infection and alleviating inflammation after treatment of 11 days. Moreover, we show that the preparative strategies of injectable supramolecular hydrogels can be extended to other polyphenols, including protocatechuic and tannic acids. This study provides a facile yet highly effective method to design injectable polyphenol- sodium alginate hydrogel for wound dressing based on naturally bioactive ingredients.

Exploring the therapeutic potential of recombinant human lysozyme: a review on wound management system with antibacterial

Lysozyme, a natural antibacterial enzyme protein, possesses the ability to dissolve the cell walls of Gram-positive bacteria, demonstrating broad-spectrum antibacterial activity. Despite its significant potential in treating wound infections and promoting wound healing, its widespread clinical application has yet to be realized. Current research is primarily focused on carrier-based delivery systems for lysozyme. In this review, we discuss four delivery systems that can be employed for lysozyme in wound healing treatment, specifically hydrogels, nanofilms, electrospun fibrous membranes, and modified-lysozyme composite systems. These systems not only enhance the stability of lysozyme but also enable its controlled and sustained release at wound sites, potentially overcoming some of the challenges associated with its direct application. Lastly, we delve into the perspectives and challenges related to the use of these delivery systems, hoping to spur further research and innovation in this promising field.