Treating colon cancer with a suicide gene delivered by self-assembled cationic MPEG–PCL micelles

Biodegradable cationic micelles show promise for applications in gene delivery. In this article, we used DOTAP to modify monomethoxy poly(ethylene glycol)–poly(ε-caprolactone) (MPEG–PCL, MP) micelles in one step, creating novel cationic self-assembled DOTAP and MPEG–PCL hybrid micelles (DMP). These micelles had a mean particle size of 46 ± 5.6 nm and a zeta potential of 41.8 ± 0.5 mV, and had the capacity to bind DNA. Compared with PEI25K (the gold standard), DMP micelles had higher transfection efficiency and lower cytotoxicity. Moreover, we used DMP to deliver the Survivin-T34A gene (S-T34A, a suicide gene) to treat colon cancer. DMP delivered the Survivin-T34A gene (DMP/S-T34A) and could induce apoptosis in cancer cells, resulting in inhibition of the growth of C-26 colon cancer cells in vitro. An in vivo study indicated that intraperitoneal administration of DMP micelles delivered the Survivin-T34A gene and efficiently inhibited the growth of abdominal metastatic C-26 colon cancer and the malignant ascites. These data suggest that DMP may be a novel gene carrier, and its delivery of the S-T34A gene may have promising applications in the treatment of colon cancer.