Waste-derived marigold flower Carbon Dots Spray and Gel formulations exhibited enhanced wound healing in deep excisional cutaneous and burn Wound

Abstract

Bioactive carbon dots have made extraordinary progress in biomedical therapeutics due to their unique physicochemical characteristics and exceptional biocompatibility. This work focuses on synthesizing, characterizing, and biomedical evaluation of carbon dots (CDs) extracted from the waste and thrown-away marigold flowers for wound healing. The synthesized CDs had a uniform size of 2-5 nm, and a zeta potential of -15.8 mV, which describes moderate stability against aggregation. Potential photoluminescence was observed to be excited-dependent at a maximum intensity of 380 nm. In comparison, the UV-Vis adsorption curve showed a peak at 278 nm corresponding to the π-π* transition of sp² carbon domains. Additional FTIR and XPS findings showed the functional groups, including hydroxyl, carbonyl, and aromatic domains, confirmed the doping of nitrogen and oxygen, improving hydrophilicity and reactivity respectively. In-vitro cytocompatibility assays using MTT and FDA showed maximum cell viability at 500 µg/ml. When examined macroscopically, a scratch assay showed encouraging results with the cells and fibroblasts achieving a 98.97% wound healing rate at 48 hours compared to control values. In-vivo experiments on deep excisional full-thickness and burn injuries exhibited enhanced wound contraction, ECM deposition, angiogenesis, and faster healing with CD gel and spray than the control and standard treatments. Histology and immunohistochemistry supported enhanced collagen synthesis and remodeling in treated tissue however, the gel demonstrated marginally superior results to the spray- more securely adhered. These results show that the developed CD (Marigold) is biocompatible, promotes angiogenesis, and enhances deep excisional and burn wound healing.