Free paclitaxel-loaded E-selectin binding peptide modified micelle self-assembled from hyaluronic acid-paclitaxel conjugate inhibit breast cancer metastasis in a murine model

The present work seeks to construct a nanovehicle for the efficient suppression of breast cancer metastasis through targeting E-selectin on tumor vascular endothelial cells and hyaluronic acid-receptor on tumor cells. Herein, a new ligand-PEG-lipid conjugate, E-selectin binding peptide-polyethene glycol-1-octadecylamine (Esbp-PEG-OA), was used as the targeting molecule of micelle self-assembled form hyaluronic acid-paclitaxel (HA-PTX) conjugate. When loaded with free PTX, the micelles (Esbp-HA-PTX/PTX) exhibited nanoscale particle size with high drug-loading capacity (up to 31.5%). In vitro release study showed that the conjugated and entrapped PTX released simultaneously. Cellular uptake of micelles confirmed that Esbp-HA-PTX micelles could be specifically and efficiently internalized into E-selectin expressing human umbilical vein endothelial cells (HUVEC) and 4T1 breast cancer cells via receptor-meditated endocytosis. In vitro cytotoxicity assay further revealed that Esbp-HA-PTX/PTX micelles significantly improved the selectivity of PTX for killing the two cell types compared with PTX solution formulation. More importantly, Esbp-HA-PTX micelles raised the accumulation of payload in tumor through targeting two cell types in the tumor microenvironment simultaneously, resulting in marked in vivo inhibition of tumor growth, intratumoral microvessel density and metastasis, and decreased systemic toxicity over solution formulation. Overall, Esbp-HA-PTX/PTX micelle is promising in therapy of breast cancer metastasis.