Lipo-poly(L-histidine) hybrid materials with pH-sensitivity, intracellular delivery efficiency, and intrinsic targetability to cancer cells.

Biocompatible lipo-histidine hybrid materials conjugated with IR820 dye show pH-sensitivity, efficient intracellular delivery of doxorubicin (Dox), and intrinsic targetability to cancer cells. These new materials form highly uniform Dox-loaded nanosized vesicles via a self-assembly process showing good stability under physiological conditions. The Dox-loaded micelles are effective for suppressing MCF-7 tumors, as demonstrated in vitro and in vivo. The combined mechanisms of the EPR effect, active internalization, endosomal-triggered release, and drug escape from endosomes, and a long blood circulation time, clearly prove that the IR820 lipopeptide DDS is a safe theranostic agent for imaging-guided cancer therapy.