BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 Poly(N-isopropylacrylamide) CHe-CH ordered water molecules minimize water-hydrophobe contacts) Hydroxypropylmethyl cellulose(natural biopolymer) Hydroxypropyl groups dehydrate to associate and form a gel o Micellar packing Pluronics PEO-PPo-PEo block copolymers Cubic lipid gel phases(3) 8小 FIG 1. Schematic model of a bicontinuous cubic phase composed monoolein wate a membrane protein, The matrix consists of Fig.2. Structure of glyceryimonoleate-water cubic phase in three and w conr ydrophobic proteins dillie latelein or mono dimensions with inset showing the lipid bilayer. (Adapted with cating aqueous channel system(see texi modifications from Refs. 14, 39) Sara bu straat 25, 1055 KV Amsterdam, The Ne (Landau and Rosenbusch 1996(4)) Lecture 8 sical gels 3of12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Lecture 8 – Physical gels 3 of 12 • Poly(N-isopropylacrylamide) ordered water molecules (minimize water-hydrophobe contacts) Dehydration allows water to disorder (entropically-driven) ∆S = Sdehydrated - Shydrated > 0 • Hydroxypropylmethyl cellulose (natural biopolymer) o Hydroxypropyl groups dehydrate to associate and form a gel o Micellar packing o Examples: ƒ Pluronics PEO-PPO-PEO block copolymers ƒ Cubic lipid gel phases(3) (Landau and Rosenbusch 1996(4))