Smart stimuli-responsive carrier-free nanoassembly of SN38 prodrug as efficient chemotherapeutic nanomedicine
Guanting Li, Qianhui Jin, Fengli Xia, Shuwen Fu, Xuanbo Zhang, Hongying Xiao, Chutong Tian, Qingzhi Lv, Jin Sun, Zhonggui He, Bingjun Sun
Abstract
The compound 7-ethyl-10-hydroxy-camptothecin (SN38) is a broad-spectrum antitumor agent whose applications are greatly limited by its poor solubility. Therefore, irinotecan, the hydrophilic derived prodrug of SN38, has been developed as the commercial formulation Campto ® for colorectal cancer. However, only 1% to 0.1% of irinotecan is converted to active SN38 in vivo, thus leading to unsatisfactory antitumor activity in clinical settings. Herein, we report a smart stimuli-responsive SN38 prodrug nanoassembly for efficient cancer therapy. First, SN38 was conjugated with an endogenous lipid, cholesterol (CST), via a redox dual-responsive disulfide bond (namely SN38-SS-CST). The prodrug self-assembled into uniform prodrug nanoassemblies with good colloidal stability and ultrahigh drug loading. SN38-SS-CST NPs released sufficient SN38 in the redox environments of tumor cells but remained intact in normal tissues. Finally, SN38-SS-CST NPs potently inhibited the growth of colon cancer without causing systemic toxicity, thus indicating their promise as a translational chemotherapeutic nanomedicine.