MMP-2-controlled transforming micelles for heterogeneic targeting and programmable cancer therapy

Herein, through the active-peptide-functionalization, we developed a nanoscale micelles system (named HEKM) which consists of tumor microenvironment-regulated shape-changing with specific recognition abilities for enhanced cellular targeting, internalization and therapy of heterogeneic tumors. As a result, HEKMs could recognize and bind the tumor heterogeneity marker EGFR-HER2 complex, which led to an enhanced tumor targeting effect. In particular, HEKMs could self-assemble into nanorods under normal physiological conditions while transform into nanospheres in the tumor extracellular microenvironment by a sensitive response to matrix metalloproteinase-2 (MMP-2). The nanorods could prolong the blood circulation time while the nanospheres could accelerate tissue penetration in tumors. In vivo dual-modal targeted imaging was realized by FRET-fluorophore conjugation and gadolinium loading in HEKMs. Tumor cell apoptosis was achieved by proapoptotic element integration. The in vitro and in vivo studies both demonstrated that these rationally designed, shape-changing and targeting micelles could achieve maximized drug efficacy and minimum side effects.