A preliminary study on the interaction between Asn-Gly-Arg (NGR)-modified multifunctional nanoparticles and vascular epithelial cells

Liu, Chunxi; Liu, Tingxian; Yu, Xiaoyue; Gu, Yizhu

Caveolae are invaginated membrane structures and are enriched in cholesterol, sphingomyelin, and caveolin protein 10 . The integrity of these sphingolipid-and cholesterol-rich microdomains depends on cholesterol. To examine whether the behavior of TPIC changed if plasmalemmal cholesterol was depleted, MβCD was used to deplete cholesterol from the cell membrane, thereby selectively destroying the formation of caveolae. According to FACS analysis (Fig. 6B) , the amount of internalized TPIC was significantly inhibited by cholesterol depletion (Po0.05). The replenishment of cholesterol by MβCD-cholesterol did not affect the amount of TPIC internalized because the exogenous cholesterol significantly reversed MβCD-induced effects 41 . Furthermore, addition of exogenous cholesterol alone did not change the amount of internalized TPIC. The amount of TPIC internalized decreased significantly in cholesterol-depleted cells but was recovered to the control level in cholesterol-depleted and -replenished cells, demonstrating that cholesterol depletion can inhibit the intracellular entry of TPIC.