Polymer-Drug Nanoparticles Combine Doxorubicin Carrier and Heparin Bioactivity Functionalities for Primary and Metastatic Cancer Treatment.

Here, a biocompatible amphiphilic copolymer of low molecular weight heparin (LMWH) and doxorubicin (DOX) connected by an acid-sensitive hydrazone bond for enhanced tumor treatment efficacy and safety has been designed and tested. The conjugate combines DOX delivery with LMWH antimetastatic capabilities. After the nanoparticles reach the tumor site, the acidic tumor microenvironment triggers the breakage of the hydrazone bond releasing DOX from the nanoparticles, which results in an increase in the cellular uptake and enhanced in vivo antitumor efficacy. A 3.4-fold and 1.5-fold increase in tumor growth inhibition were observed compared to the saline-treated control group and free DOX treated group, respectively. The LMWH-based nanoparticles effectively inhibited interactions between tumor cells and platelets mediated by P-selectin reducing metastasis of cells in both in vitro and in vivo models. The improved safety and therapeutic effect of LMWW-DOX nanoparticles offers new potential for tumor therapy.