Liposomes Aid Curcumin's Combat with Cancer in a Breast Tumor Model

Curcumin (CUR), a natural compound, has multiple antineoplastic properties and specificity toward tumor cells, however its bioavailability and water solubility are poor. Liposomes increase the therapeutic index of CUR by protecting the drug from enzymatic degradation and can be made long circulating by surface modification with polyethylene glycol (PEG). Folate receptor α (FRα) is overexpressed in several types of cancer. Therefore, a folate-conjugated liposomal CUR nanoconstruct can enhance tumor targeted drug therapy. In this study, we synthesized, characterized and tested the cytotoxicity of CUR loaded liposomes (folate modified and non-folate modified) and CUR free drug in non-malignant breast epithelial cells and breast cancer cells, in addition to assessing the effects of CUR on cell cycle. The breast cancer cells not only had increased uptake of liposomes compared to non-malignant cells, but also more showed greater cytotoxicity resulted from treatments with free CUR and liposomal CUR (folate surface-modified and non-folate liposome types). The imaging and killing results, indicated that the liposomal CUR formulations do not alter the therapeutic efficacy and selectivity of CUR to provide anticancer benefits. Moreover, the differences in cellular uptake between the two liposomal nanoconstructs were studied using flow cytometry which showed targeting of folate surface-modified liposomes in cancer cells based on the findings presented.