The skin, as the largest organ of the human body, plays a pivotal role in maintaining structural integrity and immune defense. Acting as the first line of protection, it safeguards the body against physical, chemical, and thermal threats. Continuous exposure to the external environment renders the skin highly susceptible to injuries such as burns, physical wounds, inflammatory reactions, and chronic conditions. Among these, chronic wounds especially those associated with diabetes have emerged as a major clinical challenge due to impaired natural healing processes. The increasing global preva‎lence of diabetes, along with its complications such as weakened immune function and heightened risk of bacterial infections, significantly hinders wound healing and raises the likelihood of non-healing, chronic wounds. These wounds not only impose physical and psychological burdens on patients but also place a substantial financial strain on healthcare systems. Consequently, there is a pressing need to develop innovative strategies for effective treatment and accelerated healing of diabetic wounds, particularly through the design of targeted and efficient wound dressings. An ideal wound dressing should ensure adequate moisture at the wound site, promote oxygen permeability, absorb excess exudates, prevent infections, allow easy replacement, and be biocompatible, biodegradable, non toxic, and cost effective. Although few studies have explored the combined use of silk fibroin and lignin, promising results have highlighted their synergistic effects in enhancing antibacterial, antioxidant, and cell supportive properties of wound dressings. This study aimed to fabricate and characterize lignin-based fibrous membranes using electrospinning technology for diabetic wound healing applications. Silk fibroin was initially extracted from Bombyx mori cocoons. The fabricated membranes included different lignin to fibroin weight/volume ratios (1:5, 1:6, 1:7) as well as pure fibroin, and were electrospun at voltages of 20, 25, and 30 kV. Characterization of fibroin extraction and fiber morphology was carried out using Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The results confirmed successful fibroin extraction and revealed uniform, bead-free nanofibers that mimicked the extracellular matrix structure, with 20 kV identified as the optimal voltage. The fibers were subsequently crosslinked by immersion in 96% ethanol for 30 minutes to enhance their physical stability and delay degradation. The impact of lignin content on mechanical properties, biodegradability, swelling behavior, cellular biocompatibility, antibacterial activity, and antioxidant performance was thoroughly assessed. Among the tested compositions, the 1:6 lignin-to-fibroin ratio exhibited the most favorable outcomes across multiple biological and physical eva‎luations. This composition showed a balanced mechanical profile, including tensile strength of 0.19 ± 0.08 MPa, Young’s modulus of 8.34 ± 6.47 MPa, elongation at break of 2.34 ± 0.59%, and toughness of 1.88 ± 0.86 kJ/m³. After 14 days, it exhibited only 18.76 ± 3% weight loss in phosphate-buffered saline and demonstrated high water absorption capacity (428.76 ± 64.8%). Additionally, it supported the highest cell viability (221.06 ± 18.26% after 7 days), facilitated cell adhesion, proliferation, and migration, inhibited both Gram positive and Gram negative bacteria, and displayed strong antioxidant activity (70.51 ± 6.02% over 48 hours). These findings suggest that the developed electrospun lignin fibroin nanofibrous membranes hold significant potential for application in chronic wound management, particularly for diabetic wound healing.

مهشيد خرازيهاي اصفهاني , مسعود عطاپور

عليرضا علافچيان , فاطمه داور