Drug resistance reversal in ovarian cancer cells of paclitaxel and borneol combination therapy mediated by PEG-PAMAM nanoparticles

Paclitaxel (PTX) is frequently suffered from multidrug resistance (MDR), resulting in lower chemotherapeutic efficacy and even chemotherapy failure. To combine the P-glycolprotein (P-gp) inhibitor would be a useful strategy to overcome MDR. However, what is needed now is an efficient vehicle to deliver multiple drugs into tumor simultaneously. In this study, PTX and Borneol (BNL), a natural compound with P-gp inhibition effect confirmed in intestinal absorption, were co-loaded in the fabricated PEG-PAMAM nanoparticle (NPs) by a one-step nano-precipitation method with high drug loading efficiency, narrow size distribution and low hemolysis rate. Based on P-gp inhibition activity of BNL, confirmed by drug efflux test and molecular docking model, the combination of PTX and BNL could improve intracellular concentration of PTX in A2780/PTX cells. Furthermore, compared to both free PTX and PTX+BNL, PB/NPs and P/NPs plus BNL exhibited higher cellular uptake and cytotoxicity in A2780/PTX cells, as well as the decreased MMP and enhanced apoptosis rate. More importantly, although PB/NPs and P/NPs+B showed similar tumor accumulation in tumor-bearing mice, PB/NPs could significantly decrease tumor growth of A2780/PTX tumor-bearing mice, in comparison to P/NPs+B. These results indicated the advantage of PTX and BNL co-delivery NPs for MDR reversal. These findings demonstrate that the co-delivery nano-sized system comprised by PEG-PAMAM polymer with PTX and BNL co-loaded would be a promising candidate for MDR treatment.