Enhanced Intracellular Delivery of Curcumin Using Polymeric Nanocarriers: A Natural Photosensitizing Agent for Anti-Cancer Photodynamic Therapy.

Curcumin ranks among the extensively investigated Phytocompounds with a wide array of therapeutic properties. It has bioactive and photoactive properties that enhance its potential as an anti-cancer agent. However, poor solubility and low bioavailability are associated with it which hinders its applications. To address the limitations related to free curcumin (CUR), the present study focuses on the synthesis of curcumin-loaded poly lactic-co-glycolic acid nanoparticles (CUR NPs). The single emulsion solvent evaporation technique was used to synthesize CUR NPs with an average size of 187 nm and a zeta potential of -13.3 mV. Photophysical properties, drug loading efficiency, and drug release profile of synthesized CUR NPs were studied. Confocal fluorescence imaging was employed to study the cellular uptake of both formulations of CUR. The In-vitro investigation was conducted using BT-474 human breast cancer cells to evaluate the dark and phototoxic effect of both variants of curcumin (free CUR and CUR NPs). The cytotoxicity was quantified through half-maximal inhibitory concentration (IC₅₀) obtained after conducting in-vitro dark and phototoxic experiments. The study revealed that CUR NPs showed better cytotoxic responses compared to the free CUR. During the phototoxic study, CUR NPs exhibit improved efficacy in the presence of light. The CUR NPs effectively deliver curcumin to enhance its potential in photodynamic therapy against cancer.