Self-assembling stereocomplex nanoparticles by enantiomeric poly(γ-glutamic acid)-poly(lactide) graft copolymers as a protein delivery carrier.

Amphiphilic graft copolymers, poly(γ-glutamic acid)-graft-poly(lactide) (γ-PGA-g-PLA) bearing pendent poly(L-lactide) (PLLA) or poly(D-lactide) (PDLA) of different main chain lengths and grafting degrees, self-assemble in aqueous solution to form monodispersed stereocomplex nanoparticles (NPs). The mean diameter and degree of crystallinity of these stereocomplex NPs can be controlled by changing the grafting degree of the copolymers or the preparation methods. Moreover, the stereocomplex NPs exhibit a lower critical aggregation concentration as well as stronger thermodynamic stability compared with the corresponding isomer NPs. The surface-functionalized ability and protein encapsulation capacity of the stereocomplex NPs as potential targeting protein carriers are evaluated. Furthermore, these stereocomplex NPs have strong kinetic stability and can be expected to serve as stable delivery vehicles for pharmaceutical and biomedical applications.