title: Effects of surface modification of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) on physicochemical properties and on interactions with MC3T3-E1 cells.
abstract: As a new member of the polyhydroxyalkanoate (PHA) family, poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) has better mechanical and processible properties than poly (3-hydroxybutyrate) (PHB). Still, it is difficult to introduce functional groups to the polyester carbon chain of PHBHHx, which restricts the modification of PHBHHx for a wide range. In this study, a procedure for the modification of the surface of PHBHHx films under strongly alkaline conditions was described. Through this kind of modification, carboxyl and hydroxyl groups were introduced to the surface and the total surface free energy was increased, which was mainly due to the increased polar components. Meanwhile, this process makes the surface rougher, resulting in larger total surface areas. After mineralization in simulated body fluids (SBFs), the apatite nucleation and growth on the surface-hydrolyzed PHBHHx films were significantly faster than on the unmodified PHBHHx films. This phenomenon should have a close relationship with the increased carboxyl and hydroxyl groups. The physicochemical properties also influenced the cell response to PHBHHx films. Compared to unmodified PHBHHx, fibronectin adsorption, and MC3T3-E1 cell attachment and proliferation were significantly greater on surface-hydrolyzed PHBHHx, which may be due to the increased surface free energy and rougher surface. Therefore, surface hydrolysis makes PHBHHx more suitable for osteoblast cell response and for application in bone-tissue engineering.
authors.affiliation: Department of Biological Sciences and Biotechnology, State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Huan
authors.initials: H
authors.lastname: Yun
authors.forename: Yandao
authors.initials: Y
authors.lastname: Gong
authors.forename: Nanming
authors.initials: N
authors.lastname: Zhao
authors.forename: Xiufang
authors.initials: X
authors.lastname: Zhang
mesh_terms: D020155:3-Hydroxybutyric Acid; D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials; D002208:Caproates; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts; D013816:Thermodynamics; D000094122:Polyhydroxybutyrates
chemical_list: D020155:3-Hydroxybutyric Acid; D001672:Biocompatible Materials; D002208:Caproates; C115940:poly(3-hydroxybutyrate-co-3-hydroxyhexanoate); D000094122:Polyhydroxybutyrates