Comparable Efficacy of Chitosan/miR-200b-3p and Lipofectamine/miR-200b-3p Delivered by Pluronic F127 Hydrogel to Facilitate Diabetic Wound Healing.

Background: The clinical application of miRNA therapeutics in diabetic foot ulcers (DFUs) is limited by the rapid degradation of miRNAs. We previously reported that topical lipofectamine (Lipo)-based miR-200b-3p delivery by Pluronic F127 (PF127) hydrogel has pro-healing properties in diabetic wounds. However, Lipo's high cost and cytotoxicity concerns impede its clinical use. Chitosan (CS) is an inexpensive biopolymer. We investigated whether the topical delivery of PF127+CS+miR-200b-3p can accelerate wound healing in diabetic mice. Methods: In vitro experiments were conducted, including the CCK-8 assay, gelation time measurement, scanning electron microscopy, Zetasizer Nano ZS analysis, release kinetics, swelling ratio, gel retardation assay, and uptake assay. In vivo experiments were performed on db/db mice with two 8 mm dorsal wounds. Four treatment groups including PF127, PF127+CS+miR-negative control (miR-NC), PF127+CS+miR-200b-3p, and PF127+Lipo+miR-200b-3p were examined. On day 14, skin tissues were harvested for H&E and immunohistochemical staining, as well as real-time PCR of variable genes and miR-200b-3p. Results: The CCK-8 assay revealed the non-toxicity of CS on HaCaT keratinocytes. Furthermore, PF127 concentration-dependently decreased the positive surface charge of the CS/miR-200b-3p nanoparticles. The PF127 kept the diameter of the CS/miR-200b-3p nanoparticles at roughly 200-250 nm. In vivo Conclusion: Topical delivery of CS/miR-200b-3p nanoparticles using PF127 is a promising treatment for diabetic wound healing. Our findings demonstrate that chitosan serves as a cost-effective, non-toxic alternative to Lipofectamine in diabetic wound management.