Magnetic mesoporous silica nanoparticles-aided dual MR/NIRF imaging to identify macrophage enrichment in atherosclerotic plaques

Active foamy macrophage enrichment drives atherosclerotic plaque initiation and evolution, and is the prominent target for precisely identifying vulnerable plaque. Precise imaging of high-risk plaque allows promotion of treatment and prevention of vascular pathema. However, current iron oxide (IO) nanoparticles-based magnetic resonance (MR) imaging of plaque is often limited by insufficient perfusion and nonspecific accumulation of peri-aortic lymph nodes. Besides that, intrinsic defects of MR also impede its use for accurately identifying plaque details. Herein, by conjugating with PP1 peptide, a novel magnetic mesoporous silica nanoparticle (PIMI) loaded with near-infrared fluorescence (NIRF) dye (IR820) was fabricated to specifically target and quantify macrophage enrichment of atherosclerotic plaque in ApoE(-/-) mice using dual MR/NIRF imaging. Biocompatibility experiments ulteriorly confirmed the high safety of PIMI nanoparticles in vivo, which lays the foundation of next-generation contrast agent for recognizing macrophage-rich plaque in the near future. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

The enrichment of active foamy macrophages plays a crucial role in atherosclerotic plaque formation and evolution, and is a key target for identifying vulnerable plaque. However, current magnetic resonance (MR) imaging of plaque using iron oxide nanoparticles is often limited by issues such as insufficient perfusion and nonspecific accumulation. By developing a novel magnetic mesoporous silica nanoparticle (PIMI) loaded with near-infrared fluorescence dye (IR820) and targeting macrophage enrichment in atherosclerotic plaque, this study lays the foundation for a next-generation contrast agent for recognizing macrophage-rich plaque in the future.