Electrostatic charge conversion processes in engineered tumor-identifying polypeptides for targeted chemotherapy

One of the current challenges in cancer chemotherapy is the ultra-sensitive identification of in vivo tumors. Herein, we report a new class of tumor-identifying polypeptides that can home in on in vivo tumors via an electrostatic charge conversion process occurring in the acidic milieu of a verity of tumors, which can be distinguished from receptor-interacting conventional tumor-homing peptides. We exploit the chemical coupling between polypeptides and therapeutic objects (drugs or particles) to carry out an antitumor study in nude mice, and find a significant increase in the efficiency of polypeptide-tagged objects in tumor uptake and inhibition, which is more significant than any known tumor-homing peptide system thus far developed. (C) 2011 Elsevier Ltd. All rights reserved.