Mitochondria and Nucleus Dual Delivery System To Overcome DOX Resistance

Doxorubicin (DOX) is a broad-spectrum chemotherapy drug to treat tumors. However, severe side effects and development of DOX resistance hinder its clinical application. In order to overcome DOX resistance, DOX/TPP-DOX@Pasp-hyd-PEG-FA micelles were prepared by using newly synthesized comb-like amphiphilic material Pasp-hyd-PEG-FA. Drug released in vitro from micelles showed a pH-dependent manner. DOX/TPP-DOX@Pasp-hyd-PEG-FA induced more apoptosis in KB cell and MCF-7/ADR cell than DOX@Pasp-hyd-PEG-FA. Confocal laser scanning microscopy experiment indicated that DOX/TPP-DOX@Pasp-hyd-PEG-FA delivered TPP-DOX and DOX to the nucleus and mitochondria of the tumor cell simultaneously. Thus, DOX/TPP-DOX@Pasp-hyd-PEG-FA could significantly damage the mitochondrial membrane potential. DOX/TPP-DOX@Pasp-hyd-PEG-FA markedly shrinked the tumor volume in tumor-bearing nude mice grafted with MCF-7/ADR cell as compared with the same dose of free DOX. DOX was mainly accumulated in tumor tissue after DOX/TPP-DOX@Pasp-hyd-PEG-FA was injected to tumor-bearing nude mice by tail vein. After free DOX was injected to tumor-bearing nude mice by tail vein, DOX widely distributed through the whole body. Therefore, mitochondria and nucleus dual delivery system has potential in overcoming DOX resistance.