18A-Gd

18A-Gd is a synthetic, high-density lipoprotein (HDL)-mimetic nanoparticle developed as a contrast agent for the molecular imaging of atherosclerosis using magnetic resonance imaging (MRI). The agent is composed of an 18-amino acid amphipathic peptide (18A) that serves as a functional replacement for apolipoprotein A-I (ApoA-I), the primary protein component of natural HDL. It is formulated with phospholipids and labeled with gadolinium (Gd) chelates to provide T1-weighted MRI contrast, and often includes a fluorescent tag like rhodamine for histological validation. 18A-Gd particles, which are approximately 8 nm in diameter, mimic the biological behavior of endogenous HDL, including the ability to promote cholesterol efflux and target macrophages via scavenger receptors such as SR-BI. In preclinical studies, 18A-Gd has demonstrated the ability to specifically accumulate in macrophage-rich atherosclerotic plaques, enabling the non-invasive assessment of plaque inflammation and burden.

Other names

18A-Gd-rhodamine