Co-delivery of curcumin and resveratrol by folic acid-conjugated poly(glycerol adipate) nanoparticles for enhanced synergistic anticancer effect against osteosarcoma

This study explored the co-delivery of curcumin (CUR) and resveratrol (RV) using folic acid-conjugated poly(glycerol adipate)-based nanoparticles (FPPC NPs) to enhance their synergistic anticancer effects against osteosarcoma. Based on synergistic toxicity experiments against Saos-2 cells, the optimal synergistic CUR:RV ratios were 1:2 and 1:3, which were used for co-encapsulation. Increasing the amount of RV in the co-loaded NPs did not affect the properties of the nanocarriers, but predominantly increased the loading capacity of RV, especially at the 1:3 ratio, by 1.8–2.0 times, mediated by their interaction. All co-loaded NPs demonstrated sustained release of CUR with a burst release of RV, and the presence of RV accelerated the initial release of CUR from the carriers. Furthermore, the co-encapsulated NPs maintained CUR and RV synergism and greatly enhanced their toxicity against osteosarcoma by at least 1.8 times compared to their corresponding solutions through profound accumulation of Saos-2 cells in the sub G1 phase and late apoptosis. The internalization of FPPC NPs into cells via endocytosis was dose- and time-dependent. This study offers a proof-of-concept for a potential co-delivery system using tumor-targeted poly(glycerol adipate)-based NPs to enhance the anticancer activity of CUR and RV against osteosarcoma.