Curcumin Nanoencapsulated in Chitosan-Coated Liposomes: Therapeutic Potential against Pathogenic <i>Escherichia coli</i> and <i>Leishmania</i> spp.

High Resolution Image Download MS PowerPoint Slide Infectious diseases caused by bacteria and protozoa continue to pose a critical public health challenge, exacerbated by the increasing resistance to conventional treatments. Curcumin, a broad-spectrum polyphenol with antimicrobial and antiparasitic properties, nevertheless presents clinical limitations associated with low solubility, chemical instability, and reduced bioavailability. In this study, curcumin nanoencapsulated into chitosan-coated liposomes (Lipo-CUR-Chi) was developed and characterized to evaluate its physicochemical performance, stability, antibacterial and antibiofilm activity against Escherichia coli strains, and antiparasitic efficacy against Leishmania infantum and L . amazonensis . The formulation showed high encapsulation efficiency (97.2%), stability for up to 120 days under refrigeration, and a marked increase in antimicrobial activity compared to free curcumin. A significant reduction in minimum inhibitory concentrations against E . coli was observed, along with a dose-dependent effect on biofilm formation inhibition. In RAW 264.7 macrophages, Lipo-CUR-Chi demonstrated lower cytotoxicity, indicating higher safety compared to free curcumin. In assays against Leishmania spp., CUR encapsulation resulted in increased potency and selectivity, particularly against L . amazonensis, approaching the therapeutic profile of amphotericin B but with lower toxicity. These results demonstrate that chitosan-coated liposomes are a promising platform to enhance the biological activity of curcumin, representing an innovative strategy for the treatment of bacterial and parasitic infections.