title: Structural properties and release of insulin-loaded reverse hexagonal (HII) liquid crystalline mesophase.
abstract: Insulin loading into the HIImesophases was examined as a function of its concentration, with addition of glycerol as a cosolvent and with addition of phosphatidylcholine (PC) as a structural stabilizer. The structural properties, the molecular interactions, the viscoelastic properties, and the dynamic behavior were investigated by SAXS, ATR-FTIR, and rheological measurements. Insulin release was then monitored and analyzed. Insulin incorporation into the HIIsystems shrank the cylinders as it competed with the lipids in water-bonding. Insulin interrupted the interface while increasing τmaxand creating a more solid-like response. Upon addition of PC, cooperative flow behavior was detected, which is probably the reason for increase in insulin cumulative release from 28% to 52% after 300 min. In the presence of glycerol, the system was less cooperative but insulin was more compactly folded, resulting in a slight improvement in insulin release (up to 6%). Addition of both PC and glycerol caused the maximum release (55%). The addition of additives into the HIIsystem demonstrates how structural modifications can improve insulin release, and influence future design of encapsulated drug delivery systems.
authors.affiliation: The Ratner Chair in Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel.
authors.forename: Tehila
authors.initials: T
authors.lastname: Mishraki-Berkowitz
authors.affiliation: The Ratner Chair in Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel.
authors.forename: Abraham
authors.initials: A
authors.lastname: Aserin
authors.affiliation: The Ratner Chair in Chemistry, Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel. Electronic address: garti@mail.huji.ac.il.
authors.forename: Nissim
authors.initials: N
authors.lastname: Garti
mesh_terms: D004337:Drug Carriers; D004339:Drug Compounding; D065546:Drug Liberation; D004548:Elasticity; D005989:Glycerides / Q000737:chemistry*; D005990:Glycerol / Q000737:chemistry*; D007328:Insulin / Q000737:chemistry*; D007700:Kinetics; D050866:Liquid Crystals / Q000737:chemistry* / Q000648:ultrastructure; D010713:Phosphatidylcholines / Q000737:chemistry*; D012212:Rheology; D012995:Solubility; D013816:Thermodynamics; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D004337:Drug Carriers; D005989:Glycerides; D007328:Insulin; D010713:Phosphatidylcholines; D014867:Water; C005953:monoolein; D005990:Glycerol
keywords: ATR-FTIR; Glycerol; Glycerol monooleate; Insulin; Phosphatidylcholine; Release; Reverse hexagonal mesophase; Rheology; SAXS