Shear stress and ROS-responsive biomimetic micelles for atherosclerosis via ROS consumption.

Reactive oxygen species (ROS) are well-known important initiating factors required for atherosclerosis formation, which leads to endothelial dysfunction and plaque formation. Most of the existing antithrombotic therapies use ROS-responsive drug delivery systems, which have a certain therapeutic effect but cannot eliminate excess ROS. Therefore, the atherosclerosis cannot be treated from the source. Moreover, nanoparticles are easily cleared by the immune system during blood circulation, which is not conducive to long-term circulation. In this study, we developed an intelligent response system that could simultaneously respond to ROS and the shear stress microenvironment of atherosclerotic plaques. This system was formed by red blood cells (RBCs) and simvastatin-loaded micelles (SV MC). The micelles consisted of poly(glycidyl methacrylate)-polypropylene sulfide (PGED-PPS). The hydrophobic PPS could react with excess ROS to become hydrophilic, which forced the micelle rupture, resulting in drug release. Most importantly, PPS could also significantly deplete the ROS level, realizing the synergistic treatment of atherosclerosis with drugs and materials. The positively charged SV MC and negatively charged RBCs were self-assembled through electrostatic adsorption to obtain SV MC@RBCs. The SV MC@RBCs could respond to the high shear stress at the atherosclerotic plaque, and the shear stress induced SV MC desorption from the RBC surface. Using biomimetic methods to evade the SV MC@RBCs elimination by the immune system and to reduce the ROS plays a vital role in improving atherosclerosis treatment. The results of in vitro and in vivo experiments showed that SV MC@RBCs could effectively treat atherosclerosis. Moreover, not only does the SV MC@RBCs system avoid the risk of bleeding, but it also has excellent in vivo safety. The study results indicate that the SV MC@RBCs system is a promising therapeutic nanomedicine for treating ROS-related diseases.