Synthetic HDL Binds Cholesterol

Northwestern University researchers have created a novel core-shell complex that mimics high-density lipoprotein (HDL). As part of their study, they demonstrated that the functionalized gold nanoparticles bind to a fluorescently labeled cholesterol analog and determined the first quantitative cholesterol-binding constant for a synthetic HDL (J. Am. Chem. Soc., DOI: 10.1021/ja808856z). Natural HDL, when bound to cholesterol, is known as “good” cholesterol. It transports the plaque-forming cholesterol to the liver, a mechanism that protects people against developing deadly cardiovascular diseases such as atherosclerosis. C. Shad Thaxton, Chad A. Mirkin, and colleagues synthesized the HDL mimic by wrapping a gold nanoparticle with a protein component of natural HDL and two phospholipids. The resulting structure has a similar size and surface composition as natural HDL, and its biocompatible gold core can be tailored to change the nanoparticle’s size. Other researchers have reported synthetic HDLs with gold nanocores that they designed for imaging studies (Nano Lett. 2008, 8, 3715). Mirkin says the new mimic is intended for therapeutic purposes and could potentially become the basis for a drug to raise HDL levels. In vivo studies are under way, he adds.