title: Immobilization of galactose ligands on acrylic acid graft-copolymerized poly(ethylene terephthalate) film and its application to hepatocyte culture.
abstract: Surface modification of argon-plasma-pretreated poly(ethylene terephthalate) (PET) films via UV-induced graft copolymerization with acrylic acid (AAc) was carried out. Galactosylated surfaces were then obtained by coupling a galactose derivative (1-O-(6'-aminohexyl)-D-galactopyranoside) to the AAc graft chains with the aid of a water-soluble carbodiimide (WSC) and N-hydroxysulfosuccinimide (sulfo-NHS). The modified PET films were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact-angle measurements. The galactosylated PET films were used as substrates for hepatocyte culture. The effects of surface carboxyl group concentration on the extent of galactose ligand immobilization, the extent of hepatocyte attachment, and the surface morphology were investigated. The amount of the galactose ligands immobilized on the PET surface increased with the AAc polymer graft concentration. AFM images revealed that the surface roughness of the PET film increased after graft copolymerization with AAc, but did not change appreciably with the subsequent immobilization of the galactose ligands. At the surface carboxyl group concentration of about 0.56 micromol/cm(2) or galactose ligand concentration of about 0.51 micromol/cm(2), the hepatocyte culture on the galactosylated surface exhibited the optimum concentration and physiological functions and formed aggregates or spheroids after just 1 day of culture. The albumin and urea synthesis functions of these hepatocytes were comparable to or higher than those of the hepatocytes cultured on the collagen-modified PET substrates.
authors.affiliation: Department of Chemical Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Republic of Singapore.
authors.forename: Lei
authors.initials: L
authors.lastname: Ying
authors.forename: Chao
authors.initials: C
authors.lastname: Yin
authors.forename: R X
authors.initials: RX
authors.lastname: Zhuo
authors.forename: K W
authors.initials: KW
authors.lastname: Leong
authors.forename: H Q
authors.initials: HQ
authors.lastname: Mao
authors.forename: E T
authors.initials: ET
authors.lastname: Kang
authors.forename: K G
authors.initials: KG
authors.lastname: Neoh
mesh_terms: D000179:Acrylates / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D005690:Galactose; D022781:Hepatocytes / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D008024:Ligands; D008853:Microscopy; D018625:Microscopy, Atomic Force; D011093:Polyethylene Terephthalates / Q000737:chemistry*; D013997:Time Factors; D014867:Water
chemical_list: D000179:Acrylates; D008024:Ligands; D011093:Polyethylene Terephthalates; D014867:Water; D005690:Galactose