Controlled Synthesis of Shell Cross-Linked Helical Poly(phenylborate isocyanide) Nanoparticles with HO/Redox Dual Responsiveness and Their Application in Antitumor Drug Delivery.

To mimic the helical structure and function of biopolymers, shell cross-linked nanoparticle (P4) composed of left-handed helical poly(phenylborate isocyanide) in core and hydrophilic polyisocyanide in shell was prepared. The phenylborate in the core and the disulfide bonds in the cross-linkage render the nanoparticle with excellent dual stimuli-responsiveness to glutathione (GSH) and HO. Nevertheless, it has good stability in normal physiological conditions. Because of the helicity and borate pendants of the core, such nanoparticle has high capacity for anticancer drug loading, for example, the loading capacity of doxorubicin (DOX) was up to 68%. Moreover, the DOX-loaded DOX@P4 showed excellent tumor cell penetration potency and fast drug release. More than 78% of murine breast cancer cell (4T1) can be killed within 48 h, supporting this material with great potential in antitumor drug nanocarriers.