Promising wound healing activity of Saussurea costus loaded PCL–gelatin nanofibers

Abstract

Wound healing is a complex process, including inflammation, tissue formation, and remodeling. Saussurea costus (Sc) is reported to possess antimicrobial and anti-inflammatory activities. In this study, we manufactured polycaprolactone–gelatin nanofibers loaded with 6% Sc extract (PCL–GL-6% Sc) for wound healing applications. Comprehensive characterization confirmed the structural integrity and functionality of the prepared nanofibers. SEM results showed an increase in diameter of PCL–GL upon encapsulation of Sc. FTIR and XRD verified chemical bonding and crystallinity of the nanofibers, respectively. TGA demonstrated thermal stability, while tensile strength testing confirmed durability, and both parameters are critical for wound dressing applications. The Sc release profile showed controlled bioactive release, which supports sustained healing effects. Lastly, contact angle measurements indicated hydrophilicity, supporting cellular adhesion, which is necessary for wound recovery. Antimicrobial assessments showed significant activities of PCL–GL-6% Sc nanofibers against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, with a log reduction of around 7 in the PCL–GL-6% Sc group. Cytotoxicity tests on human skin fibroblasts revealed no significant difference between PCL–GL-6% Sc treated cells vs. untreated cells. In vivo studies in albino rats showed enhanced epithelial regeneration and collagen deposition, with significant downregulation of interleukin-6 (IL-6) (p ≤ 0.05) and upregulation of B-cell lymphoma protein 2-associated X (BAX) (p ≤ 0.0001) and matrix metalloproteinase-3 (MMP-3) (p ≤ 0.01). Immunohistochemistry supported these findings with moderate expression of vascular endothelial growth factor (VEGF) and transforming growth factor beta-1 (TGF-β1), alongside high BAX expression. In conclusion, PCL–GL-Sc 6% Sc holds potential as an effective dressing for wound healing applications.