title: Photocrosslinked layered gelatin-chitosan hydrogel with graded compositions for osteochondral defect repair.
abstract: A layered gelatin-chitosan hydrogel with graded composition was prepared via photocrosslinking to simulate the polysaccharide/collagen composition of the natural tissue and mimic the multi-layered gradient structure of the cartilage-bone interface tissue. Firstly, gelatin and carboxymethyl chitosan were reacted with glycidyl methacrylate (GMA) to obtain methacrylated gelatin (Gtn-GMA) and carboxymethyl chitosan (CS-GMA). Then, the mixed solutions of Gtn-GMA in different methacrylation degrees with CS-GMA were prepared to form the superficial, transitional and deep layers of the hydrogel, respectively under the irradiation of ultraviolet light, while polyhedral oligomeric silsesquioxane was introduced in the deep layer to improve the mechanical properties. Results suggested that the pore sizes of the superficial, transitional and deep layers of the layered hydrogel were 115 ± 30, 94 ± 34, 51 ± 12 μm, respectively and their porosities were all higher than 80 %. The compressive strengths of them were 165 ± 54, 565 ± 50 and 993 ± 108 kPa, respectively and the strain of the gradient hydrogel decreased along the thickness direction, similar to the natural tissue. The in vitro cytotoxicity results showed that the hydrogel had good cytocompatibility and the in vivo repair results of osteochondral defect demonstrated remarkable recovery by using the gradient gelatin-chitosan hydrogel, especially when the hydrogel loading transforming growth factor-β1. Therefore, it was suggested that the prepared layered gelatin-chitosan hydrogel in this study could be potentially used to promote cartilage-bone interface tissue repair.
authors: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin, 300072, People's Republic of China.
authors: Fengxuan
authors: F
authors: Han
authors: Xiaoling
authors: X
authors: Yang
authors: Jin
authors: J
authors: Zhao
authors: Yunhui
authors: Y
authors: Zhao
authors: Xiaoyan
authors: X
authors: Yuan
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry* / Q000627:therapeutic use; D048271:Chitosan / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use*; D019245:Compressive Strength; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000528:radiation effects; D050724:Fractures, Cartilage / Q000473:pathology / Q000628:therapy*; D005780:Gelatin / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use; D020100:Hydrogels / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use; D008027:Light; D008422:Materials Testing; D010777:Photochemistry; D016062:Porosity; D011817:Rabbits; D016896:Treatment Outcome
chemical_list: D003432:Cross-Linking Reagents; D020100:Hydrogels; D005780:Gelatin; D048271:Chitosan