Wound Healing Effect of Dendrimer-Based Nano-Fluconazole/Nano-Chitosan on Cutaneous Leishmaniasis in Mice: Insights into the Mechanism of Action via NMR-Based Metabolomics

Background Cutaneous leishmaniasis (CL), mainly caused by Leishmania major ( L. Major ), poses significant therapeutic challenges due to drug resistance, and adverse effects of conventional treatments. This study developed a dendrimer-based nanostructure combining fluconazole, an antileishmanial and antifungal agent, with chitosan, a biocompatible polymer exhibiting antileishmanial, antibacterial, and wound-healing properties. NMR-based metabolomics was employed to elucidate the underlying mechanisms of action. Methods A dendrimer was synthesized and conjugated with chitosan and fluconazole. Nanostructures were characterized by DLS, SEM, and FTIR, and evaluated for drug loading, solubility, and release kinetics. Anti-leishmanial efficacy was assessed in vitro against L. major promastigotes and in vivo in BALB/c mice through lesion size monitoring. Metabolic profiling via NMR analyzed drug/parasite interactions, while cytotoxicity and systemic toxicity were evaluated using macrophage assays, hematological, biochemical, and histopathological analyses. Results The nanostructure exhibited nanoscale size, uniform morphology, and efficient drug conjugation, with loading efficiencies of 49% (chitosan), and 56% (fluconazole). Encapsulation enhanced solubility and enabled sustained release. The NFLZ/Chi formulation demonstrated potent in vitro activity (IC₅₀ = 13 µg/mL) with synergistic effects (CI = 0.61) and achieved 97% wound healing in vivo. Metabolomics revealed significant disruption of amino acid, carbohydrate, and lipid metabolism, particularly branched-chain amino acids and glycine/serine/threonine pathways. Toxicity evaluations confirmed high biocompatibility and minimal hepatic alterations. Conclusion This dendrimer-based nanostructure effectively targets L. major , combining direct anti-parasitic effects with metabolic disruption, improved drug delivery, and accelerated wound healing, while exhibiting minimal toxicity. These results support its potential as a safe and efficient therapeutic strategy for CL.