Shoeblackplant extract-loaded carboxymethyl cellulose/collagen scaffolds seeded with adipose-derived stem cells enhance diabetic wound healing via immunomodulation and angiogenic pathways.

BACKGROUND

Diabetic wounds are a chronic condition where the typical cascade of wound healing is compromised due to unresolved inflammation, oxidative stress, and dysfunctional angiogenesis. Bioactive dressings with combined stem cell and plant extract-based formulations can provide a multifactorial therapeutic approach for diabetic wounds. The study was aimed at evaluating the wound healing potential of shoeblackplant extract-loaded carboxymethyl cellulose/collagen (CMCCOL) scaffolds seeded with adipose-derived stem cells in vitro and in vivo.

METHODS

Porous CMCCOL scaffolds loaded with shoeblackplant extract (5 %, 7.5 %, and 10 % v/v) were developed by the freeze-drying method and crosslinked using EDC/NHS. Rat adipose-derived stem cells were seeded on the scaffolds for seven days to fabricate ASCs-seeded CMCCOL scaffolds. The cytocompatibility, MTT assay, bacterial penetration test, anti-inflammatory assay (ELISA), Transwell® migration assay, mechanical tensile strength, biodegradation, and drug release profile was evaluated in vitro. The in vivo wound healing study was performed using a full-thickness wound on diabetic rats and treated with ASC-seeded scaffolds, extract-free scaffolds, commercial dressing (Mepilex® foam), or sterile gauze as a control. On day 14, the wound area reduction and histological analysis (H&E and Masson's Trichrome) were assessed. Wound healing was also evaluated by histomorphometry, while ELISA was performed for IL-6, TNF-α, IL-10, VEGF-A, TGF-β1, MMP-9, and TIMP-1.

RESULTS

The results showed interconnected porous network architecture, cytocompatibility, and appropriate mechanical properties for the scaffolds. In addition, extract and ASCs-loaded scaffolds demonstrated enhanced migration, inhibited the secretion of pro-inflammatory cytokines, and exhibited sustained release of bioactives. In vivo, all the treated groups displayed higher wound closure rates, complete re-epithelialization, more organized collagen deposition, and angiogenesis as compared to the control group. ELISA also confirmed the decrease in IL-6, TNF-α, and MMP-9, while IL-10, VEGF-A, TGF-β1, and TIMP-1 were upregulated.

CONCLUSION

In conclusion, shoeblackplant extract-loaded CMCCOL scaffolds seeded with ASCs improved diabetic wound healing with the help of anti-inflammatory, pro-angiogenic, and pro-regenerative properties. However, it requires further validation with large animal models for clinical translation.