Cluster of Differentiation-44-Targeting Prussian Blue Nanoparticles Onloaded with Colchicine for Atherosclerotic Plaque Regression in a Mice Model

Atherosclerosis management heavily relies on the suppression of the inflammatory response of macrophages. Colchicine's potent anti-inflammatory properties make it a promising candidate for secondary prevention against cardiovascular disease. However, its high toxicity and numerous adverse effects limit its clinical use. To address this, there is an urgent need for specific drug delivery systems to boost the level of accumulation of colchicine within atherosclerotic plaques. In this study, the cluster of differentiation-44 receptor was verified to be overexpressed in inflammatory macrophages within plaques both in vitro and in vivo. Subsequently, a Prussian blue-based nanomedical loading system with hyaluronic acid (HA) coating was constructed, and its effects were observed on the atherosclerosis regression. Colchicine and Cy5.5 were encapsulated within Prussian blue nanoparticles through self-assembly, followed by conjugation with hyaluronic acid to create col@PBNP@HA. The formulated col@PBNP@HA displayed a cubic shape and scattered distribution. Importantly, col@PBNP@HA demonstrated specific cellular uptake into lipopolysaccharide-stimulated macrophages. In vitro experiments showed that col@PBNP@HA more effectively inhibited expression of inflammatory factors and scavenged reactive oxygen species compared with the control group, which were treated with colchicine. Furthermore, col@PBNP@HA exhibited its specific and higher accumulation in aortic plaque analysis via fluorescence imaging of aortas. After 4 weeks, administration of col@PBNP@HA resulted in significant atherosclerosis regression in the mice model, with therapeutic effects superior to those of free colchicine. Similar to colchicine, col@PBNP@HA inhibited the secretion of inflammation factors and scavenged ROS through the regulation of the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (Myd88)/nuclear factor kappa-B (NF-κB) and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) signaling pathway. In summary, col@PBNP@HA demonstrated specific targeting ability to inflammatory plaques and exerted beneficial effects on atherosclerosis regression through TLR4/Myd88/NF-κB and PGC-1α modulation.