title: Inhibition of cholesterol transport into skin cells in cultures by phytosterol-loaded microemulsion.
abstract: Cholesterol and plant phytosterols are lipophilic compounds solubilized by intestinal micelles in a competitive manner. In this work, we used radioactive cholesterol- and phytosterol-loaded oil-in-water microemulsions to follow their incorporation and mutual competition in HaCaT keratinocytes, SZ95 sebocytes, and skin pieces in cultures. Dynamic light scattering showed homogenous nanostructures of 10.5+/-1.5 nm diameter and cryo-transmission electron microscopy confirmed the presence of uniform spherical droplets of 7.0+/-1.0 nm diameter. Up to 320 nmol/ml of cholesterol can be solubilized and transported into cells with minimal toxic effect by 0.5 wt% nanodroplets in a cell medium. Phytosterols inhibit incorporation of cholesterol into cells, in vitro, at molar ratios (phytosterols/cholesterol) of 4 and above. The loaded nanodroplets accumulate in intracellular vesicles (presumably endosomes). No metabolic conversion of cholesterol or phytosterols was found in these cells, in vitro, after 24 h, at 37 degrees C.
authors.affiliation: Casali Institute of Applied Chemistry, The Institute of Chemistry, Givat Ram Campus, The Hebrew University of Jerusalem, Jerusalem, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Rozner
authors.forename: L
authors.initials: L
authors.lastname: Verkhovski
authors.forename: Y
authors.initials: Y
authors.lastname: Nissimov
authors.forename: A
authors.initials: A
authors.lastname: Aserin
authors.forename: R
authors.initials: R
authors.lastname: Vilensky
authors.forename: D
authors.initials: D
authors.lastname: Danino
authors.forename: C C
authors.initials: CC
authors.lastname: Zouboulis
authors.forename: Y
authors.initials: Y
authors.lastname: Milner
authors.forename: N
authors.initials: N
authors.lastname: Garti
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002775:Cholestadienols / Q000494:pharmacology; D002784:Cholesterol / Q000378:metabolism*; D020285:Cryoelectron Microscopy; D004655:Emulsions / Q000494:pharmacology; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D010840:Phytosterols / Q000494:pharmacology*; D012855:Sitosterols / Q000378:metabolism / Q000494:pharmacology
chemical_list: D002775:Cholestadienols; D004655:Emulsions; D010840:Phytosterols; D012855:Sitosterols; C003532:brassicasterol; C025473:gamma-sitosterol; D002784:Cholesterol