A Shear‐Thinning, Self‐Healing, Dual‐Cross Linked Hydrogel Based on Gelatin/Vanillin/Fe³⁺/AGP‐AgNPs: Synthesis, Antibacterial, and Wound‐Healing Assessment

Abstract

A shear‐thinning and self‐healing hydrogel based on a gelatin biopolymer was synthesized using vanillin and Fe3+ as dual crosslinking agents. Rheological studies indicate the formation of a strong gel found to be injectable and exhibit rapid self‐healing (within 10 minutes). The hydrogels also exhibited a high degree of swelling, suggesting potential as wound dressings since the absorption of large amounts of wound exudate, and optimum moisture levels, lead to accelerated wound healing. Andrographolide, an anti‐inflammatory natural product was used to fabricate silver nanoparticles, which were characterized, and composited with the fabricated hydrogels to imbue them with anti‐microbial activity. The nanoparticle/hydrogel composites exhibit activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Burkholderia pseudomallei (B. pseudomallei), the pathogen that causes melioidosis, a serious but neglected disease affecting southeast Asia and northern Australia. Finally, the nanoparticle/hydrogel composites are shown to enhance wound closure in animal models compared to the hydrogel alone, confirming that these hydrogel composites hold great potential in the biomedical field.This article is protected by copyright. All rights reserved

Advancements and Challenges in Self-Healing Hydrogels for Wound Care

“…Metal coordination and ionic crosslinking leverage metal ions and polymer interactions to establish networks that are both stable and reversible. This approach enhances the hydrogels' mechanical attributes and introduces bioactive functionalities, making them particularly effective for wound healing and antibacterial purposes [32,33,35,36,39,104].…”

“…Shear-thinning and self-healing hydrogels, composed of gelatin, vanillin, and iron ions and loaded with andrographolide silver nanoparticles, offer excellent antibacterial activity and promote wound closure in animal studies [36]. Bioinspired hydrogel sealants, comprising sodium alginate, gelatin, protocatechualdehyde, and ferric ions, provide robust bonding strength, injectability, and self-healing and encourage incision healing and closure [37].…”

“…The table also shows major tests conducted to evaluate the hydrogels for their intended applications. Chitosan crosslinked with silver and copper ions Antibacterial capability, adhesive ability, water absorption ability, biocompatibility, diabetic wound healing in rat models [32] Carboxymethyl chitosan crosslinked with Fe 3+ and Al(3+) ions Gelation process, self-healing, self-adaption, thermo-responsive ability, skin tissue regeneration, wound closure [33] Oxidized sodium alginate-grafted dopamine/carboxymethyl chitosan/Fe 3+ Self-healing properties, conductivity, photothermal antibacterial properties, rheological properties, mechanical properties, antioxidant properties, tissue adhesion properties, hemostatic properties, in vivo infected wound healing [34] Gelatin and copolymer of dimethyl aminoethyl methacrylate with 2-acrylamido-2-methylpropane sulfonic acid crosslinked with ferric ions Mechanical strength, pore size via SEM, biodegradation rate under visible light, toxicity (MTT assay for L-929 cell line), histological studies in vivo [35] Gelatin/vanillin/Fe 3+ crosslinked with andrographolide-modified silver nanoparticles Self-healing capability; swelling degree; antibacterial activity against E. coli, S. aureus, and B. pseudomallei; wound closure in animal models [36] Sodium alginate, gelatin, and protocatechualdehyde with ferric ions Mechanical and adhesive strength, injectability and self-healing capacity, biocompatibility, photothermal antibacterial activity, antioxidation, hemostatic effect, in vivo incision closure evaluation [37] Gelatin conjugated with 2-(4'-aldehydephenyl)-4-(2',3',4'trihydroxyphenyl)-2,3-phthalazine-1(2h)-one and Fe 3+ ions Mechanical property, tissue adhesion, self-healing capability, biocompatibility, hemostatic and antibacterial activity, wound healing in skin infection rat model [38] Multi-Arm thiolated polyethylene glycol crosslinked with silver nitrate Injectable and self-healing properties, antibacterial and angiogenic in vitro, diabetic skin wound repair, enhancement of angiogenic activity [39] Hydrophobic CuS-grafted-curcumin and carboxymethyl cellulose modified with aldehyde groups and hydroxypropyl trimethyl ammonium chloride chitosan…”

“…Moreover, the effectiveness of these materials and their clinical outcomes varies significantly due to factors such as wound type and location, tissues' physiological conditions, and individual patient characteristics like pre-existing health conditions [2,11,20,21,34,36,43,58,64,87,88,113]. This variability stresses the need for personalized treatment strategies and further research to tailor applications to individual patient needs.…”

“…These innovations focus on effectively addressing local bacterial infections while minimizing the risk of resistance. They achieve this by incorporating multifunctional features into hydrogel dressings, catering to a diverse range of wound care requirements [31][32][33][34][35][36][37][38][39][40][41].…”