Tumor metastasis emerges as a crucial target for tumor therapy. In this study, a tumor metastasis targeting peptide（TMT） was conjugated to a lipid material（PEG-DSPE） to obtain the targeting compound（TMT-PEG-DSPE）, which was used to construct the targeted liposomal doxorubicin（TMT-LS-DOX）. We showed that TMT-LS-DOX presented satisfactory pharmaceutical characteristics. This metastasis-specific delivery system was tested in two highly metastatic breast cancer cell lines（MDA-MB-435S and MDA-MB-231） with a non-metastatic breast cancer cell line（MCF-7） as the control. The free TMT peptide itself showed no cytotoxicity even at the concentration of 100 μg/mL. Importantly, the enhanced cellular uptake of TMT-LS-DOX to both MDA-MB-435S and MDA-MB-231 cell lines was demonstrated as compared to MCF-7 cells, via a TMT-mediated mechanism demonstrated by a receptor competition study. In conclusion, the TMT modified nanocarriers might provide a strategy to enhance the specificity of chemotherapeutic agents to highly metastatic breast cancer.
