Transferrin-anchored poly(lactide) based micelles to improve anticancer activity of curcumin in hepatic and cervical cancer cell monolayers and 3D spheroids

Abstract

In recent years, actively targeted drug delivery systems have been utilized in pre-clinical studies for site-specific delivery of drugs, which reduces toxicities associated with chemotherapy. This study reports the preparation of the tumor homing ligand, transferrin (Tf) anchored methoxy-polyethylene glycol-poly(d,l-Lactide) polymeric micelles (Tf-PP). Curcumin which possess wide anti-cancer activity was loaded into the micelles. Tf-PPC with average particle size of 132.16 ± 1.37 nm and encapsulation efficiency of 88.27 ± 2.53% showed a sustained drug release. The efficacy of Tf-PPC was studied in vitro in Tf-overexpressing human cervical carcinoma (HeLa) and human hepatoma (HepG2) cells. The mouse embryo fibroblast (NIH-3T3) cells were used as control cells. Tf-PPC showed higher internalization compared to non-targeted micelles (PPC). The curcumin-mediated cytotoxicity increased significantly following Tf-PPC treatment in both the tested cell lines. In NIH-3T3 cells, Tf conjugation did not differ in comparison to the non-targeted micelles. Further, the efficiency of Tf-PPC was studied in three-dimensional (3D) HeLa tumor spheroids. The Tf-PPC was efficiently internalized by the spheroidal structures, causing higher cytotoxicity and apoptosis compared to PPC. These results reveal that the newly developed, Tf-PPC could be employed as an effective chemotherapy in the treatment of Tf- overexpressing cancers.