Bio-inspired keratin-based core-crosslinked micelles for pH and reduction dual-responsive triggered DOX delivery

Facile bio-inspired approach has been developed to prepare novel DOX-loaded chicken feather keratin-based core-crosslinked micelles (DOX/Ker-PEG CCMs) for pH and reduction dual-responsive tumor-specific intracellular triggered DOX delivery, by oxidation crosslinking the DOX/Ker-PEG micelles which were simply self-assembled by adjusting solution pH value to 10. The final DOX/Ker-PEG CCMs with a mean hydrodynamic diameter of 152 nm were obtained with a drug loading capacity (DLC) of 24.8%. The in vitro controlled release profiles demonstrated the pH and reduction dual-responsive triggered release of DOX from the developed bio-inspired drug delivery system (DDS), with a cumulative release of 58% within 3 days in a sustained release manner in the stimulated tumor intracellular microenvironment, while a low premature drug leakage of 14% occurred in the normal physiological medium. Furthermore, the MTT assays demonstrated that the graft copolymer Ker-PEG₅₈ possessed excellent cytocompatibility, while the DOX/Ker-PEG CCMs exhibited an enhanced anti-tumor efficacy on the HepG2 cells than the free DOX.