Nanovesicle-mediated delivery of anticancer agents effectively induced cell death and regressed intrahepatic tumors in athymic mice

Hepatocellular carcinoma is highly resistant to chemotherapy. Here we evaluated the use and efficacy of milk-derived nanovesicles (MNV) as an approach to improve delivery of anticancer agents into HCC cells and intrahepatic tumors. We developed a protocol for isolation of MNVs from skim milk using ultracentrifugation, and characterized using nanoparticle tracking analysis (NTA) and electron microscopy. MNVs were loaded with doxorubicin (dox-MNV) or miR221 antisense oligonucleotides (anti-miR221-MNV), and further evaluated using spectrophotometry, NTA, and zeta potential measurements. HepG2, Hep3B, and PLC/PRF/5 HCC cells in culture were treated with dox-MNV and anti-miR221-MNV and evaluated with drug delivery and anticancer activity. The efficacy of dox-MNV and anti-miR221-MNV to arrest tumor growth in vivo was assessed on intrahepatic tumors induced in nude mice. Cellular uptake studies showed plain and dox-MNV attained saturation within 4 h of treatment. Cytotoxicity studies on HepG2, Hep3B, and PLC/PRF/5 HCC cells with dox-MNV at 1 µM resulted in 20% cell death at 24 h, 50% at 48 h, and 80% at 72 h. HepG2 cells treated with dox-MNV and anti-miR221-MNV exhibited nuclear disintegration, and apoptosis within 24 h. Combination treatment of intrahepatic tumors with dox-MNV and anti-miR221-MNV resulted in marked reduction of tumor size and increased survival rate in nude mice. Our studies demonstrated that MNVs can be effectively used for successful delivery of anticancer agents into HCC cells and intrahepatic tumors. MNV-mediated targeted delivery of anticancer agents could be an efficient modality for the treatment of malignant HCC and might produce a great impact on anticancer therapy.