Enhanced macrophage polarization induced by COX-2 inhibitor-loaded Pd octahedral nanozymes for treatment of atherosclerosis

摘要

Inhibition of foam cell formation is considered a promising treatment method for atherosclerosis,the leading cause of cardiovascular diseases worldwide.However,currently available therapeutic strategies have shown unsatisfactory clinical outcomes.Thus,herein,we design aloperine(ALO)-loaded and hyaluronic acid(HA)-modified palladium(Pd)octahedral nanozymes(Pd@HA/ALO)that can synergistically scavenge reactive oxygen species(ROS)and downregulate cyclooxygenase-2(COX-2)expression to induce macrophage polarization,thus inhibiting foam cell formation to attenuate atherosclerosis.Due to the targeted effect of HA on stabilin-2 and CD44,which are overexpressed in atherosclerotic plaques,Pd@HA/ALO can actively accumulate in atherosclerotic plaques.Subsequently,the antioxidative effects of Pd octahedral nanozymes are mediated by their intrinsic superoxide dismutase-and catalase-like activities capable of effective scavenging of ROS.In addition,anti-inflammatory effects are mediated by controlled,on-demand near-infrared-triggered ALO release leading to inhibition of COX-2 expression.Importantly,the combined therapy can promote the polarization of macrophages to the M2 subtype by upregulating Arg-1 and CD206 expression and downregulating expression of TNF-α,IL-1βand IL-6,thereby inhibiting atherosclerosis-related foam cell formation.In conclusion,the presented in vitro and in vivo data demonstrate that Pd@HA/ALO enhanced macrophage polarization to reduce plaque formation,identifying an attractive treatment strategy for cardiovascular disease.