A nanotherapy responsive to the inflammatory microenvironment for the dual-targeted treatment of atherosclerosis

Atherosclerosis remains the main cause of death and disability, as well as a leading cause of coronary arterial disease. Inflammation is one of the pathogenic factors of arteriosclerosis; however, the current treatments based on lowering the level of inflammation in the plaque tissue of patients with atherosclerosis are not clinically used. Herein, we hypothesize that αvβ3 receptor affinity and low pH sensitivity may be regarded as a valid therapeutic strategy for targeting sites of atherosclerosis according to the microenvironments of inflammation. To prove this tentative hypothesis, an acid-labile material polyketal named PK3 was synthesized, and the cRGDfc peptide was used to modify nanoparticles composed of poly(lactide-co-glycolide) (PLGA), lecithin, and PK3, loaded with the anti-atherosclerotic drug rapamycin (RAP). The nanoparticles were prepared using an O/W method and then characterized, which showed an appropriate particle size and fulfilling responsive behaviors. In vitro release studies and stability tests showed that these nanoparticles can be effectively internalized by human umbilical vein endothelial cells (HUVEC), and also show a good in vitro anti-inflammatory effect. After intravenous (i.v.) injection, RGD targeted by pH-responsive nanotherapy (RAP-Nps-RGD) may be accumulated at the plaque site in ApoE-/- mice with atherosclerosis and can effectively attenuate plaque progression compared to other formulations. Moreover, its good safety profile and biocompatibility have been revealed in both in vitro and in vivo estimations. Accordingly, the prospect of nanoparticles responsive to the inflammatory microenvironment for preventing atherosclerotic through inflammation modulation provides great feasibility for the administration of alternate drug molecules to inflamed sites to slow down the process of arteriosclerosis.