Co-delivery of paclitaxel and survivin siRNA with cationic liposome for lung cancer therapy

This work designed a new delivery system (L-PTX-PSur), which could efficiently co-deliver paclitaxel (PTX) and survivin siRNA (Sur) to overcome the dose-limiting toxicity by effectively accumulating PTX in tumor and obtain enhanced therapy by synergistic effect. In this co-delivery system, protamine was selected to condense siRNA into a compacted ‘core’, and a carbamate-linked cationic lipid was used to develop PTX-loaded liposome to entrap the core. L-PTX-PSur with protamine could facilitate Sur entry into NCI-H460 cells and exhibited high encapsulation efficiency of PTX. In vitro studies on the NCI-H460 lung cancer cells revealed that L-PTX-PSur offered significant advantages over the control groups, and it had the highest cellular uptake, the lowest cell viability and the strongest apoptosis. Western blot result showed that survivin protein expression could be noticeably suppressed by L-PTX-PSur in NCI-H460 cells. And the down-regulation of survivin protein could lower the apoptotic threshold of cancer cells and render PTX more effective with low doses. Collectively, L-PTX-PSur with a low dose of PTX could induce a synergistic inhibitory effect on cancer cells growth by the collaboration of PTX and Sur. This work provides a promising strategy for the treatment of lung cancer.