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.

Nanoparticle-modified chitosan-agarose-gelatin scaffold for sustained release of SDF-1 and BMP-2

“…24 There is another possibility of self-cross-linking of chitosan and gelatin chains. 40 Different concentrations of polymers were utilized in this study (data not shown). Among the different combinations of varying polymer concentrations, we found good mechanical stability using a 1% chitosan concentration with 1% gelatin and 2% or 3% agarose in the polymer solution mixture (Table 2).…”

Hidrogeles de polimerización in situ para la regeneración de cartílago articular. [In-situ-forming hydrogels for articular cartilage repair]

“…Estos pueden diseñarse para mimetizar aspectos fundamentales del ambiente nativo, para proveer de señales apropiadas a las células que se siembran en él, mientras se ajustan precisamente las propiedades mecánicas, químicas y degradadoras del hidrogel. [60][61][62][63][64] Por ejemplo, el porcentaje de hidratación también se puede regular para asemejarse al del cartílago nativo (~80%) y favorecer el intercambio celular de substratos, y productos peri-y extracelulares. 14 Las ventajas de los polímeros naturales son su biocompatibilidad, su similitud bioquímica con el cartílago nativo y su facilidad para ser degradados (p.…”

Photocrosslinked tyramine-substituted hyaluronate hydrogels with tunable mechanical properties improve immediate tissue-hydrogel interfacial strength in articular cartilage

“…[9, 21, 22] Injectable hydrogel systems, which can be gelled in situ , are advantageous since their applications can be minimally invasive and directly delivered to the damage site. [9] Such injectable hydrogel systems include those based on poly(ethylene glycol),[23–25] gelatin,[26, 27] chitosan,[27, 28] alginate,[29] chondroitin sulfate,[30] carboxymethylcellulose,[31] poly(vinyl alcohol),[32, 33] and HA. [34–39] While implanted materials must be biocompatible and meet the mechanical needs of the tissue,[5, 8, 9] they must also integrate with the surrounding tissue, in this case forming a cartilage-hydrogel interface.…”