<span lang="EN">Multifunctional Alginate–Keratin Hydrogel Enriched with Althaea officinalis Extract for Antibacterial Wound Dressings

Chronic wound infections, particularly those caused by antibiotic-resistant Staphylococcus aureus, represent a major global health burden, necessitating advanced naturally derived wound dressings with intrinsic antibacterial activity. This study aimed to fabricate a novel composite hydrogel scaffold based on sodium alginate, keratin, and Althaea officinalis extract, and identify the optimal formulation for wound dressing applications. Three alginate-to-keratin weight ratios (۷۰:۳۰, ۵۰:۵۰, and ۳۰:۷۰) were fabricated via ionic crosslinking with CaCl₂ followed by freeze-drying, and each formulation was loaded with Althaea officinalis extract at ۰%, ۲.۵%, ۵%, ۸%, and ۱۰% (w/v). Scaffolds were characterized for morphology (SEM), chemical interactions (FTIR), swelling ratio, in vitro biodegradation (۲۷ days), water vapor transmission rate (WVTR), water solubility, and antibacterial activity against S. aureus, Escherichia coli, and Pseudomonas aeruginosa. SEM revealed interconnected porous networks with pore diameters of ۲۰۰–۴۰۰ µm, with the A۷۰:K۳۰ formulation exhibiting the most uniform distribution (۲۸۰ ± ۳۵ µm). FTIR confirmed successful integration of all three components, with hydrogen bonding between alginate and keratin and physical entrapment of phenolic compounds (۱۵۱۰, ۱۴۵۰ cm⁻¹). The A۷۰:K۳۰ formulation with ۱۰% extract demonstrated superior performance: swelling ratio of ۲۳۵۰ ± ۱۲۰% (vs. ۱۸۵۰ ± ۹۵% without extract, p < ۰.۰۱), biodegradation of ۸۲ ± ۵% at day ۲۷, WVTR of ۴۲۵ ± ۲۲ g/m²·h, and solubility of ۲۱ ± ۲.۸%. Antibacterial activity was selective against Gram-positive S. aureus. The A۷۰:K۳۰ with ۱۰% extract produced the largest inhibition zone (۱۸.۰ ± ۱.۲ mm), comparable to gentamicin (۱۹.۵ ± ۱.۰ mm), and the MIC of the hydrogel-eluted extract against S. aureus was ۱۰ mg/mL. In conclusion, the A۷۰:K۳۰ hydrogel scaffold loaded with ۱۰% Althaea officinalis extract exhibits optimal physicochemical properties and potent anti-staphylococcal activity comparable to standard antibiotics, positioning it as a promising naturally derived, cost-effective, and biocompatible wound dressing for managing infected chronic wounds.

کلیدواژه ها:

Hydrogel ، Sodium Alginate ، Keratin ، Althaea officinalis ، Antibacterial Activity ، wound healing