title: Stimuli responsive deswelling of radiation synthesized collagen hydrogel in simulated physiological environment.
abstract: Collagen hydrogels were prepared via radiation crosslinking. The simulated physiological environmental effects related to their biomedical applications on the volume phase transition of collagen hydrogel were studied, that is stimuli response to ions, temperature, and pH. The deswelling behavior of collagen hydrogel depends on the salt concentration, temperature, pH, and the hydrogel preparation procedure. Meanwhile, hydrogel structure related to the volume phase transition was investigated by FTIR, fluorescence spectrum, and HR-MAS NMR. Deswelling in salt solution caused little change on collagen conformation, and a denser network led to more significant tyrosine-derived fluorescence quenching. Hydrogen bonding between hydrated water and collagen polypeptide chain was dissociated and the activity of hydrophobic side chain increased, inducing a higher extent of contraction with the increasing of salt concentration. Moreover, salt solution treatments weakened the electrostatic interactions, side chains interactions, and hydrogen bonding of collagen hydrogel, which reduced the thermal stability of collagen hydrogel. Comparing with cell-free collagen hydrogel contraction, fibroblasts did not aggravate contraction of collagen hydrogel significantly. This study elucidated the deswelling mechanism of radiation crosslinked collagen hydrogel in simulated physiological environment and provides strategies for controlling the stimuli response of collagen hydrogel in biomedical application.
authors.affiliation: Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871, China.
authors.forename: Xiangmei
authors.initials: X
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.forename: Shicheng
authors.initials: S
authors.lastname: Wei
authors.forename: Maolin
authors.initials: M
authors.lastname: Zhai
authors.forename: Jiuqiang
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D002460:Cell Line; D003094:Collagen / Q000138:chemical synthesis / Q000737:chemistry*; D005347:Fibroblasts / Q000378:metabolism; D005720:Gamma Rays; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000138:chemical synthesis / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D051379:Mice; D013696:Temperature; D054457:Tissue Scaffolds / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D007477:Ions; D014867:Water; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D003094:Collagen