Optimization and preparation of doxycycline-loaded chitosan nanoparticles using Box-Behnken design for better diabetic wound healing

A diabetic wound is one of the most devastating difficulties associated with diabetes and leads to significant death and morbidity. Hence, the aim was to make Doxycycline-loaded chitosan nanoparticles (DOX-CNPs) using ionic gelation with a cross-linking technique. In the Box-Behnken design, the DOX-CNPs were optimized by considering the effects of the following 3 variables independently, namely chitosan, sodium tripolyphosphate in volume ratio, strength of chitosan and sodium tripolyphosphate, among several response variables related to nanoparticle properties. The Fourier transform infrared, transmission electron microscopy, differential scanning calorimeter, X-ray diffraction, particle size, entrapment efficiency, and drug release in-vitro were used to characterized the nanoparticles. Additionally, DPPH scavenging activity and activity against Escherichia coli and Staphylococcus aureus bacteria and in vivo characterization were carried out to optimize DOX-CNPs. Then effective delivery of DOX-CNPs is incorporated in chitosan hydrogel for diabetic wounds. The findings of this study indicate that DOX-CNPs exhibit free radical scavenging properties, demonstrate significant antibacterial activity, and enhance cell viability and migration in an in vitro wound healing assay using the L929 fibroblast cell line, and in vivo demonstrate increased blood vessels, collagen deposition epithelization. Chitosan could be used as a drug carrier in a DOX-chitosan-NP system to help develop procedures that can be used in the lab and to treat diabetic wounds.