PVA/chitosan-based hydrogels integrated with tilapia skin-derived collagen and Urtica dioica offers a promising approach for effective burn wound healing via transcriptional modulation of bFgf, Mmp2, Jak/Stat3, and α-Sma signaling pathway.

Cutaneous wound repair is governed by a highly coordinated physiological cascade that includes recruitment of inflammatory cells, release of cytokine mediators, deposition of extracellular matrix components, and subsequent remodeling of scar tissue. Nowadays, plant extracts are viewed as an efficient alternative for wound healing. Urtica dioica (U. dioica) is rich in diverse bioactive plant compounds with varied therapeutic effects and appears to support skin wound repair. However, the molecular mechanisms and signaling pathways through which they influence regenerating tissues and cells remain poorly understood. This study aimed to confirm the signaling cascade and mechanism of topical application of a hydrogel formulation incorporated with tilapia (Oreochromis niloticus L.) skin-derived collagen and U. dioica extract on the skin regeneration process based on histopathological, TEM assessment as well as analyze alterations in the expression of key wound healing-related genes, such as Jak/Stat3, Smad3, fibroblast growth factor 2 (fgf2) genes, Acta2 ( α smooth muscle actin), and matrix metalloproteinases (Mmp2) gene in rat burn model. UPLC-ESI-MS/MS also analyzed the chemical composition of U. dioica. Thirty-five animals were randomly allocated to seven groups (n = 5 per group): negative control (NCtrl; no treatment), positive control (PCtrl), hydrogel base treated group (Hgb G), tilapia collagen hydrogel (ColHgb G), MEBO® cream (MEBO G), U. dioica extract (UD G), and a combination of collagen hydrogel plus U. dioica extract (ColHgb-UD G). Burn wound (2 × 2 cm) were made on the back of each generally anaesthetized rat, and wound surface area was measured on days 0, 3, 6, 9, 12, and 15 post-burn. The animals were then sacrificed, and tissues were collected for histological, TEM, and molecular analysis. Our results showed that the methanolic extract of the aerial parts of Urtica dioica was predominantly composed of flavonoids and fatty acids. Analysis in the negative ionization mode enabled the identification of several flavonoids, including apigenin, isorhamnetin, taxifolin, and eriodictyol, detected in both free and glycosylated forms. Wound closure was faster in the ColHgb-UD group than in the control-positive group. Gene expression patterns showed that U. dioica-treated rats, either alone or mixed with collagen hydrogel, notably inhibited the expression of profibrotic factors Jack/Stat3 and Acta2, while activating angiogenesis Fbgf2, Smad3 as well as Mmp2 compared with the positive control group. The histopathological findings showed significant healing progress in the ColHgb-UD group compared with the positive control untreated group and the other treated groups. Results demonstrate superior wound healing performance for ColHgb-UD compared to the control positive group the synergistic effect of U. dioica and collagen showed less scarring, more blood capillaries, less inflammatory cells therefore remarkably healed faster making the extract ideal for wound healing applications and a novel drug candidate for wound healing.