Lecithin-chitosan nanoparticles for co-delivery of curcumin and β-caryophyllene-potential applications in chronic...

Chronic skin wounds pose a significant challenge due to persistent inflammation, elevated oxidative stress, and high susceptibility to microbial colonization. To support wound healing, this study investigated lecithin-chitosan nanoparticles co-loaded with curcumin and β-caryophyllene, two natural compounds with complementary anti-inflammatory, antioxidative, and antimicrobial properties. Co-loading curcumin and β-caryophyllene produced near-spherical nanoparticles with consistent size distribution (200-240 nm) and favourable surface charge (+30-35 mV) for topical applications. The in vitro release studies showed gradual, sustained curcumin release over 24 h, with encapsulation modestly affecting permeation. Furthermore, ABTS and DPPH assays revealed strong radical scavenging activity of curcumin, comparable to vitamin E and slightly lower than vitamin C, supporting its potential to mitigate oxidative damage in chronic wounds. Anti-inflammatory activity was confirmed via nitric oxide inhibition in lipopolysaccharide-induced murine macrophages, where co-loaded nanoparticles significantly reduced NO production in a concentration-dependent manner. Cytotoxicity testing showed that while free curcumin reduced cell viability, the encapsulated compound was notably non-toxic. The nanoparticles also demonstrated strong antimicrobial activity against Staphylococcus aureus, reducing bacterial growth to nearly zero in the co-loaded formulation. These findings highlight curcumin and β-caryophyllene co-loaded lecithin-chitosan nanoparticles as a promising platform for topical chronic wound treatment, offering dual delivery and synergistic effects against inflammation, oxidative stress, and infection. To our knowledge, this is the first study to co-deliver curcumin and β-caryophyllene in lecithin-chitosan nanoparticles, enabling a unified antioxidant, anti-inflammatory, and antimicrobial strategy for chronic wound therapy.