Efficient Treatment of Atherosclerosis by Dexamethasone Acetate and Rapamycin Co-Loaded mPEG-DSPE Calcium Phosphate Nanoparticles

Atherosclerosis (AS) is one of the leading causes of vascular disease, producing high morbidity and mortality in many countries. Autophagy plays an important role when cells are facing serious circumstances, such as oxidative stress induced by Ox-LDL (oxidized low-density lipoprotein). Recent studies have revealed that DEX (dexamethasone acetate) and RAPA (rapamycin) exhibit efficient AS therapeutic ability by protecting endothelial cells and killing foam cells, respectively. Herein, we hypothesize that combining DEX and RAPA together in a specific nanocarrier system can achieve better AS therapy while limiting harmful effects. As a proof of concept, DEX and RAPA coloaded mPEG_2k-DSPE calcium phosphate (CaP) nanoparticles (DR-NPs) were prepared by using a biomineralization method. DR-NPs increased HUVEC survival and induced foam cell apoptosis in vitro, which were correlated with autophagy activity. DR-NPs efficiently aggregated at AS plaques in the carotid artery and abdominal artery in ApoE^{- / -} mice 24 h after i.v. injection. Moreover, DR-NPs exhibited excellent plaque regression ability, with smaller necrotic cores and lipid core areas observed after in vivo treatment. Furthermore, the function of vascular endothelial cells was largely promoted, as evidenced by the dramatically decreased expression levels of adhesion factors, such as MMP-2, MMP-9 and ICAM-1. Consequently, DR-NPs can act as an effective AS therapeutic agent and broaden the AS therapeutic approach by inducing autophagy.