title: Thermoresponsive hydrogels from phosphorylated ABA triblock copolymers: a potential scaffold for bone tissue engineering.
abstract: A series of thermoresponsive and biocompatible ABA triblock copolymers in which the outer A blocks comprise poly(N-isopropylacrylamide) and the central B block consists of O-phosphoethanolamine (PEA) grafted poly(acrylic acid) (PAA(PEA)) are achieved by atom transfer radical polymerization (ATRP) and subsequent modification. At a relatively low concentration (2 w/v% in phosphate buffered saline), the triblock copolymers can form free-standing gels at 37 °C. Using a combination of variable-temperature 1H NMR, dynamic light scattering, and rheological measurements, it is demonstrated that the gelation behavior is highly dependent on both the length of A blocks and the substitution degree of phosphate group. To examine the potential application as scaffold for bone tissue engineering, the physical gels are incubated in the simulated body fluid (SBF) for 2 weeks. Obvious nucleation and growth of hydroxyapatite are found in the gels, as indicated by the scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction measurements. The triblock copolymers also exhibit low cytotoxicity in cell viability test. Thus the triblock copolymers have great potential for bone tissue engineering.
authors.affiliation: College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
authors.forename: Zaifu
authors.initials: Z
authors.lastname: Lin
authors.forename: Shuqin
authors.initials: S
authors.lastname: Cao
authors.forename: Xingyu
authors.initials: X
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Wu
authors.forename: Jianshu
authors.initials: J
authors.lastname: Li
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D001861:Bone Regeneration; D017886:Durapatite / Q000378:metabolism; D004983:Ethanolamines / Q000737:chemistry; D005782:Gels; D006801:Humans; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry; D008422:Materials Testing; D010766:Phosphorylation; D058105:Polymerization; D011108:Polymers / Q000737:chemistry; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014961:X-Ray Diffraction
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D004983:Ethanolamines; D005782:Gels; D020100:Hydrogels; D011108:Polymers; C052970:poly-N-isopropylacrylamide; C006903:carbopol 940; C005448:phosphorylethanolamine; D017886:Durapatite