title: Injectable biodegradable hydrogels with tunable mechanical properties for the stimulation of neurogenesic differentiation of human mesenchymal stem cells in 3D culture.
abstract: We report an injectable hydrogel scaffold system with tunable stiffness for controlling the proliferation rate and differentiation of human mesenchymal stem cells (hMSCs) in a three-dimensional (3D) context in normal growth media. The hydrogels composed of gelatin-hydroxyphenylpropionic acid (Gtn-HPA) conjugate were formed using the oxidative coupling of HPA moieties catalyzed by hydrogen peroxide (H(2)O(2)) and horseradish peroxidase (HRP). The stiffness of the hydrogels was readily tuned by varying the H(2)O(2) concentration without changing the concentration of polymer precursor. We found that the hydrogel stiffness strongly affected the cell proliferation rates. The rate of hMSC proliferation increased with the decrease in the stiffness of the hydrogel. Also, the neurogenesis of hMSCs was controlled by the hydrogel stiffness in a 3D context without the use of any additional biochemical signal. These cells which were cultured in hydrogels with lower stiffness for 3 weeks expressed much more neuronal protein markers compared to those cultured within stiffer hydrogels for the same period of time.
authors.affiliation: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors.forename: Li-Shan
authors.initials: LS
authors.lastname: Wang
authors.forename: Joo Eun
authors.initials: JE
authors.lastname: Chung
authors.forename: Peggy Pui-Yik
authors.initials: PP
authors.lastname: Chan
authors.forename: Motoichi
authors.initials: M
authors.lastname: Kurisawa
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D002478:Cells, Cultured; D003460:Crystallization / Q000379:methods; D004548:Elasticity; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D007267:Injections; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D009474:Neurons / Q000166:cytology* / Q000502:physiology; D010316:Particle Size; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels