A Hybrid Bi-layered Scaffold from Silk Fibroin-Gelatin nanofibers and Egg yolk oil-loaded Tragacanth Hydrogel as a promising wound dressing

Abstract Hybrid wound dressings such as nanofibers-hydrogel structures have been developed to prevent infection and accelerate wound healing. The main objective of this study was to fabricate a hybrid scaffold composed of silk fibroin (SF)–gelatin (Ge) nanofibers and tragacanth(TG) hydrogel loaded with egg yolk oil(EYO) for burn wound applications.The TG hydrogel, serving as a flexible drug carrier, was loaded with egg yolk oil, which is well known for its burn-healing efficacy. Silk fibroin was employed for its regenerative properties and low scarring potential. FESEM results revealed that SF-Ge-PVA nanofibers, prepared at a volume ratio of 1:1:2 and electrospun under 18kV with a 12cm nozzle-to-collector distance, exhibited bead-free and uniform morphology with an average diameter of 201 ± 18 nm. Contact angle and swelling studies demonstrated that both the hydrogel layer and the hybrid nanofiber–hydrogel structure were hydrophilic, with swelling ratios of 1106% and 902%, respectively. MTT assay results confirmed the absence of cytotoxicity in both EYO-loaded and unloaded hybrid structures. Furthermore, the SF-Ge-PVA nanofibers combined with EYO-loaded hydrogel exhibited excellent antibacterial activity against Gram-positive bacteria, achieving 99.97% elimination of bacterial colonies. Overall, these findings suggest that the developed hybrid scaffold is a highly promising material for burn wound healing applications.