Encapsulation of cytarabine into casein coated iron oxide nanoparticles (CCIONPs) and study of in vitro drug release and anticancer activities

Abstract

The problems of undesired surface oxidation and agglomeration of iron oxide nanoparticles have been addressed by coating of iron oxide with casein by emulsion crosslinking of casein and in situ precipitation of iron oxide nanoparticles. The study further undertook loading of cytarabine drug into casein coated iron oxide nanoparticles (CCIONPs) and evaluation of their anticancer activity under in vitro conditions. The nanoparticles were characterized by TEM for their morphology and the results revealed that the prepared nanoparticles are almost regular in geometry and have the core-shell type structure in the size range of 95 ± 0.035 nm to 150 ± 0.064 nm. Interestingly, Cyt. Loaded CCIONPs were found to inhibit the cell colony formation of liver HepG2 cells. It was found that Cyt. loaded CCIONPs significantly suppressed the relocation and invasion abilities of liver (HepG2) cancer cells. CCIONPs displayed excellent cytotoxicity against four types of cancerous cell lines like lung, breast, and liver. The obtained percentage of cells in cell cycle at G2/M stage was 8.13% and 22.29% at 50 μg/mL concentration of CCIONPs in HepG2 and SNU398, respectively. They also exhibited good apoptosis stimulation and remarkably prohibited the cell growth by arresting G2/M cell division at checkpoint. The immunoblot study affirmed significant dynamization of caspase-3 in apoptosis process, while the suppression of CDK6, PARP-1 and NF-κB were confirmed by the Western blot. The apoptosis results exhibited that Cyt loaded CCIONPs (25 and 50 μg/mL showed 0.3% and 6.33% apoptotic subpopulation in both HepG2 cells within 24 h (contact time). Immunocytochemistry also showed significant reduction in CDK6 localize protein and effectively exerted cytotoxic effect against HepG2 cells. In essence, Cyt. loaded CCIONPs prominently displayed tumoricidal effects in liver cancer cells in vitro by down regulatin of CDK6, PARP-1 and NF-κB. The study concluded that the cytarabine loaded CCIONPs could be excellent nanocarriers for the magnetically triggered release of the anticancer drug.