Intravenous delivery of enzalutamide based on high drug loading multifunctional graphene oxide nanoparticles for castration-resistant prostate cancer therapy

Abstract Background: Enzalutamide (Enz) has shown limited bioavailability via oral administration. It is easy for patients to develop into castration-resistant prostate cancer (CRPC) due to resistance to 18-24 months of androgen deprivation therapy (ADT). Moreover, it is hard to delivery Enz in vivo for low drug loading (DL) and encapsulation efficiency (EE).Therefore, we developed a multifunctional enzalutamide-loaded graphene oxide nanosystem (TP-GQDss/Enz) for castration-resistant prostate cancer (CRPC) intravenous treatment, with high drug loading efficiency. Methods: Aminated graphene quantum dots (GQDs) were first cross-linked via disulfide bonds into a graphene quantum dot derivative of approximately 200 nm (GQDss), which was further functionalized with a tumour-targeting peptide and PEG to form TP-GQDss. Enz was loaded into TP-GQDss for in vitro and in vivo study. Results: The results showed that high drug-loading efficiency was achieved by TP-GQDss via π-π electron interaction. TP-GQDss could be rapidly internalized by CRPC cells via endocytosis. Moreover, Enz in TP-GQDss could promote the inhibition of cell growth in vitro against CRPC cells. Further, TP-GQDss exhibited an enhanced cancer-targeting ability and alleviated the side effects of Enz in vivo. Conclusions: The multifunctional nanocarrier constructed here could accomplish controlled Enz release and serve as an intravenous therapy platform for CRPC.