Chitosan || Biobran/PVA || Chitosan/PVA tri-layered nanofiber scaffold: A biphasic release system with physicochemical properties conducive to skin tissue engineering

• Tri-layer nanofiber scaffolds of chitosan, PVA, and Biobran were fabricated via layer-by-layer electrospinning for STE. • Layer-by-layer electrospinning addressed chitosan’s mechanical and degradation limitations. • Biobran improved the scaffold's physicochemical properties and its antioxidant activity. • A surface wettability gradient induced a self-pumping effect, facilitating better exudate removal and moisture control. • The scaffold demonstrated cytocompatibility, antioxidant activity, antibacterial properties, and immune modulation potential. Successful regeneration of the skin requires an interdisciplinary approach that is both biological and material in consideration. In all the various strategies in skin tissue engineering (STE), electrospinning stands out for its ability to produce ECM-like scaffolds that support healing. Chitosan and Biobran are very promising polysaccharides for biomedical uses. Chitosan has antimicrobial, biocompatibility, and cell growth promotion properties, while Biobran is a safe, nontoxic agent that enhances nanofiber properties and stimulates the immune response. In the current study, our goal was to optimize a nanofiber scaffold for STE by using these materials. Hence, two types of tri-layer nanofiber scaffolds (TNS) were created by layer-by-layer electrospinning: T0, lacking Biobran in the middle layer, and T30, containing Biobran. We evaluated morphology, chemical structure, thermal stability, moisture control, mechanical properties, degradation rates, drug release, biocompatibility, antioxidant activity, and antibacterial activity by FE-SEM, FT-IR, TGA, stress-strain analysis, WCA, drug release tests, CCK-8 assays, live/dead staining, and SEM for cell assessment. Our strategy of layer-by-layer electrospinning chitosan, polyvinyl alcohol (PVA), and Biobran is a multifunctional scaffold with excellent cytocompatibility, antimicrobial activity, antioxidant activity, biphasic release, mechanical stability, and other characteristics, making it not only suitable for STE but also other biomedical applications. This graphical abstract presents the step-by-step fabrication of the tri-layer nanofiber scaffold, its characterization, and key findings demonstrating its promise for skin tissue engineering.