Tumor-targeting peptide functionalized PEG-PLA micelles for efficient drug deliveryElectronic supplementary information (ESI) available. See DOI: 10.1039/c9bm02036e

Because of their excellent capacity to significantly improve the bioavailability and solubility of chemotherapy drugs, block copolymer micelles are widely utilized for chemotherapy drug delivery. In order to further improve the anti-tumor ability and reduce unwanted side effects of drugs, tumor-targeting peptides were used to functionalize the surface of polymer micelles so that the micelles can target tumor tissues. Herein, we synthesized a kind of PEG-PLA that is maleimide-terminated and then conjugated with a specific peptide F3 which revealed specific capacity binding to nucleolin that is overexpressed on the surface of many tumor cells. Then, F3 conjugated, paclitaxel loaded nanoparticles (F3-NP-PTX) were prepared as stable micelles that displayed an enhanced accumulation viaa peptide-mediated cellular association in human breast cancer cells (MCF-7). Furthermore, F3-NP-PTX showed a prominent anti-tumor efficacy compared with non-targeting nanoparticles (NP-PTX) both in vitroand in vivo, and showed great potential as an efficacious targeting drug delivery system for breast cancer treatment.