Iminoboronate Backbone-Based Hyperbranched Polymeric Micelles with Fenton-Like Enhanced ROS Response

摘要

Compared to normal cells, there is a relatively high level of reactive oxygen species (ROS) in tumor cells caused by defecting ROS scavenging systems. To this issue, developing ROS-responsive nanocarriers has been a promising way to cancer therapy. However, it is always difficult for a certain ROSresponsive nanocarrier to be perfectly triggered due to the complexity of cancerous tissues. Thus, it is pressing to improve the response sensitivity of ROS-responsive nanocarriers. Herein, the Fenton-like reaction enhanced ROS response of polymeric nanocarriers of an iminoboronate backbone-based hyperbranched polymer with metallisable 8-hyroxyquinoline (HQ) moieties is demonstrated. HQ-Cu catalytic sites can be formed at the prepared nanocarriers via the complexation of Cu(II) ions and HQ moieties. Upon H_2O_2, hydroxyl radicals (·OH) are quickly generated via the Fenton-like reaction between H_2O_2 and HQ-Cu. Then, the oxidative cleavage of iminoboronate moieties can be effectively activated to disrupt the nanocarriers, leading to a rapid release of encapsulated drugs. It is proposed that this kind of polymeric nanocarriers with Cu-complexed catalyzing-triggered ROS response may achieve highly effective oxidation therapy.