Ionically-crosslinked milk protein nanoparticles as flutamide carriers for effective anticancer activity in prostate...

In this study, casein (CAS) nanoparticles were used to encapsulate the hydrophobic anticancer drug, flutamide (FLT), aiming at controlling its release, enhancing its anti-tumor activity, and reducing its hepatotoxicity. The nanoparticles were prepared by emulsification of CAS, at pH below its isoelectric point, and stabilized via ionic-crosslinking with sodium tripolyphosphate (TPP). The nanoparticles were spherical and positively charged with a size below 100 nm and exhibited a sustained drug release up to 4 days. After intravenous administration into prostate cancer-bearing rats for 28 days, FLT-loaded CAS nanoparticles showed a higher anti-tumor efficacy as revealed by a significantly higher % reduction in PSA serum level (75%) compared to free FLT (55%). Moreover, the nanoparticles demonstrated a marked reduction in the relative weights of both prostate tumor and seminal vesicle (43% and 32%) compared to free FLT (12% and 18%), respectively. A significantly higher anti-proliferative, anti-angiogenic, and apoptotic effects was demonstrated by the nanoparticles compared to drug solution as evidenced by their ability to decrease the expression of the proliferative marker (Ki-67) and reduce the level of tumor angiogenic markers (VEGF and IGF-1) as well as their ability to activate caspase-3 with subsequent induction of apoptosis in prostate cancer cells. Conclusively, these novel ionically-crosslinked milk protein nanovehicles offer a promising carrier to allow controlled intravenous delivery of hydrophobic anticancer drugs.