Fabrication of Curcumin Micellar Nanoparticles with Enhanced Anti-Cancer Activity

Although curcumin is effective in killing cancer cells, its low water solubility and inadequate bioavailability remain major limitations to its therapeutic application. Formulating curcumin micellar nanoparticles (Cur-NPs) encapsulated with a biodegradable polymer can significantly improve curcumin's solubility, stability, and bioavailability in vitro. In this study, differently sized Cur-NPs coated with polyvinyl alcohol (PVA) were engineered. The particle size, encapsulation efficiency, in vitro release, stability, cytotoxicity, and cellular uptake of these Cur-NPs were characterized in several cancer cell lines. The results showed that, relative to solubilized curcumin, Cur-NPs demonstrated higher cytotoxicity against cancer cells. To our knowledge, this study is the first to demonstrate that the extent of the anti-cancer potency and cellular uptake of Cur-NPs is directly correlated to particle size, where Cur-NPs with the smallest size (28 nm) were the most potent. Confocal microscopy revealed the subcellular localization of the smaller Cur-NPs (28 nm) to be in both the nucleus and cytoplasm, while the larger particles (200 nm) were only localized in the cytoplasm.