title: Poly(phosphoester) ionomers as tissue-engineering scaffolds.
abstract: Regenerative medicine requires scaffolds of divergent physicochemical properties for different tissue-engineering applications. To this end, a series of biodegradable poly(phosphoester) ionomers of the general composition [p(BHET-EOP-HOP/TC)] was synthesized, with BHET(bis-hydroxyl ethylene phosphate):EOP(ethylene phosphate):HOP(free phosphate) ratios of 60:20:20, 70:10:20, and 75:5:20, respectively. The 60/20/20 ionomer possessed the best tensile properties, exhibiting an average tensile modulus of 68 MPa and strain at break of 31%. Calcium treatment of the ionomer films led to significantly higher hardness and elastic moduli as measured by indentation. Calcium binding was evident from the increase in glass transition and melting temperatures, and a shift in the P-->O absorption in the FTIR spectrum. Stable N-hydroxysuccinimide ester (NHS) of the ionomers could be synthesized to facilitate derivatization, as demonstrated by conjugation of GRGDS in this study. The polymers conjugated with NHS were hydrolyzed in a biphasic mode, with a fast initial phase occurring in the first few hours, followed by a slower phase in the next few days. These ionomers represent a novel class of biomaterials with readily controllable physical and chemical attributes for tissue engineering.
authors.affiliation: Department of Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: Andrew C A
authors.initials: AC
authors.lastname: Wan
authors.forename: Hai-Quan
authors.initials: HQ
authors.lastname: Mao
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.forename: Su Hui
authors.initials: SH
authors.lastname: Phua
authors.forename: Gin Ping
authors.initials: GP
authors.lastname: Lee
authors.forename: Jisheng
authors.initials: J
authors.lastname: Pan
authors.forename: Shen
authors.initials: S
authors.lastname: Lu
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D004548:Elasticity; D008422:Materials Testing; D015394:Molecular Structure; D010710:Phosphates / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D010710:Phosphates; D011108:Polymers; D002118:Calcium