Resistance to single or multiple chemotherapeutic drugs is a major complication in clinical oncology and is one of the most common treatment limitations in patients with reoccurring cancers. Nanoparticle (NP)-based drug delivery systems (DDS's) have been shown to overcome drug resistance in cancer cells mainly by avoiding the activation of efflux pumps in such cells. We demonstrate for the first time that polyester-based hyperbranched dendritic-linear (HBDL)- based NPs carrying doxorubicin (Dox) can effectively overcome microsomal glutathione transferase 1 (MGST1)-mediated drug resistance in breast cancer cells. Our DDS was much more effective at considerably lower intracellular Dox concentrations (IC50 6.3 �M vs. 36.3 �M) and achieved significantly greater reductions in viability and induced higher degrees of apoptosis (31% vs. 14%) compared to the free drug in the resistant cells. These results suggest that HBDL NPs can modulate subcellular drug distribution by specific endocytic and trafficking pathways and that this results in drug delivery that alters enzyme levels and cellular signaling pathways and, most importantly, increases the induction of apoptosis. Our findings suggest that by exploiting the cell transport machinery we can optimize the polymeric vehicles for controlled drug release to overcome drug resistance combat drug resistance with much higher efficacy.

Engineered biocompatible polyester nanoparticles for the treatment of resistant cancer

248th National Meeting (2014)

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