Synthesis of polymer lipid nanoparticles loaded with Quercetin: Potential for Activating Autophagy to Promote Apoptosis of Breast Cancer Cells

Abstract Studies have shown that autophagy plays an important role in breast cancer progression and treatment. We have emphasized on preparation and optimization of polymer lipid nanoparticles loaded with quercetin (Q-PLNs) and nano-targeted therapeutic strategies on autophagy modulation. Q-PLNs had uniform particle size, good stability, and sustained release effect. Q-PLNs greatly promoted cellular uptake with lower IC50 and increased apoptotic rate. It was discovered that low-dose autophagy inhibitor CQ could partially block behavior of Q-PLNs, suggesting that Q-PLNs could induce autophagy in MCF-7 cells. Apoptosis and Western blot experiment reflected that Q-PLNs activated autophagy and apoptosis of MCF-7 cells by regulating AMPK/mTOR/ULK1 signal activity. In conclusion, polymer lipid nanoparticles were good delivery carriers to improve stability and pharmacological activity of quercetin. The pro-apoptotic effect of Q-PLNs was related to autophagy activation. The initiation mechanism of quercetin induced autophagy in MCF-7 cells presented a basis for further investigation of molecular biological mechanism.