Evaluating the Antimicrobial Activity of Curcumin-loaded Lipid Nanocarriers When Applying Photodynamic and Sonodynamic Therapy for the Treatment of Skin Infections.

PURPOSE: The antimicrobial activity of curcumin is the focus of this article, which sought to enhance it by formulating curcumin in lipid nanocarriers, and by applying Sonodynamic Therapy (ST) and Photodynamic Therapy (PT).

METHODOLOGY: Curcumin-loaded lipid nanocarriers were formulated and characterized for size, zeta potential, morphology, FTIR, and DSC. The performance of the formulation was evaluated using antioxidant activity assays, in vitro release assays, occlusion assays, and stability assays under various conditions. The distribution of curcumin in pig skin in vitro was assessed using permeability assays and visualized by confocal microscopy. The antimicrobial activity was assessed against Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, applying PT or ST under different conditions. The cytotoxicity of the formulation was evaluated using HaCaT cells.

RESULTS AND DISCUSSION: The curcumin-loaded lipid nanocarriers had a size of 63 nm, a polydispersity index of 0.202, a zeta potential of -41 mV, and an encapsulation efficiency > 95%. The properties of curcumin were enhanced by the lipid nanocarrier formulation, including stability, antioxidant activity, and skin-penetrating capacity. The antimicrobial activity of the formulation against the two strains was very low when combined with PT (< 12%), whereas ST achieved complete inhibition of P. aeruginosa. HaCaT viability was unaffected by the formulation or light.

CONCLUSIONS

The proposed formulation may be a promising alternative for improving curcumin properties, preserving its stability, and enhancing its antimicrobial activity, particularly when combined with ST.