A multifunctional polyacrylonitrile fibers/alginate-based hydrogel loaded with chamomile extract and silver sulfadiazine for full-thickness wound healing.

Most conventional wound dressings do not meet the clinical requisites owing to their limited multifunctionality. Herein, a bilayer wound dressing containing both hydrogel and fibrous structures with multifunctional features was developed for effective skin rehabilitation. Sodium alginate (SA)/gelatin (Gel) hydrogel comprising Matricaria chamomilla L extract and silver sulfadiazine (AgSD) drug as antibacterial agents was cross-linked using genipin and CaCl. Then, the surface of the hydrogel was covered by electrospun polyacrylonitrile (PAN) nanofibers to fabricate a bilayer dressing. FESEM images revealed formation of continuous, smooth, and bead-free PAN nanofibers with excellent compatibility between hydrogel and fibers. The bilayer wound dressing exhibited satisfactory mechanical virtues including elastic modulus (2.4 ± 0.2 MPa), tensile strength (6.2 ± 0.5 MPa) and elongation at break (21.8 ± 1 %) as well as suitable swelling ratio. Such bilayer dressing revealed biodegradability, cytocompatibility and effective antibacterial performance against gram positive and gram negative strains. Release kinetics of AgSD drug followed a Fickian diffusion mechanism, ensuring sustained drug release. In vivo studies demonstrated bilayer dressing could promote rate of wound closure, re-epithelialization and collagen deposition, facilitating the replacement of damaged skin with healthy tissue. Such engineered wound dressing has a high potency for inducing skin repair and could be used in skin tissue engineering.