Efficient Delivery of Gemcitabine by Estrogen Receptor-Targeted PEGylated Liposome and Its Anti-Lung Cancer Activity In Vivo and In Vitro

Lung cancer is one of the main causes of cancer-related deaths. At present, the main treatment method for lung cancer is chemotherapy. Gemcitabine (GEM) is widely applied in lung cancer treatment, but its lack of targeting ability and serious side effects limit its application. In recent years, nanocarriers have become the focus of research to solve the above problems. Here, we prepared estrone (ES)-modified GEM-loaded PEGylated liposomes (ES-SSL-GEM) for enhanced delivery by identifying the overexpressed estrogen receptor (ER) on lung cancer A549 cells. We studied the characterization, stability, release behavior, cytotoxicity, targeting ability, endocytosis mechanism, and antitumor ability to prove the therapeutic effect of ES-SSL-GEM. The results showed that ES-SSL-GEM presented a uniform particle size of 131.20 +/- 0.62 nm, a good stability, and a slowly released behavior. Moreover, ES-SSL-GEM enhanced tumor-targeting ability, and the endocytosis mechanism studies confirmed that the ER-mediated endocytosis had the most crucial effect. Furthermore, ES-SSL-GEM had the best inhibitory effect on A549 cell proliferation and significantly suppressed the tumor growth in vivo. These results suggest that ES-SSL-GEM is a promising agent for treating lung cancer.