Graphene Oxide‐Doped Gellan Gum–PEGDA Bilayered Hydrogel Mimicking the Mechanical and Lubrication Properties of Articular Cartilage. Issue 7 (15th February 2021) - Trucco, Diego
Abstract: Articular cartilage (AC) is a specialized connective tissue able to provide a low‐friction gliding surface supporting shock‐absorption, reducing stresses, and guaranteeing wear‐resistance thanks to its structure and mechanical and lubrication properties. Being an avascular tissue, AC has a limited ability to heal defects. Nowadays, conventional strategies show several limitations, which results in ineffective restoration of chondral defects. Several tissue engineering approaches have been proposed to restore the AC's native properties without reproducing its mechanical and lubrication properties yet. This work reports the fabrication of a bilayered structure made of gellan gum (GG) and poly (ethylene glycol) diacrylate (PEGDA), able to mimic the mechanical and lubrication features of both AC superficial and deep zones. Through appropriate combinations of GG and PEGDA, cartilage Young's modulus is effectively mimicked for both zones. Graphene oxide is used as a dopant agent for the superficial hydrogel layer, demonstrating a lower friction than the nondoped counterpart. The bilayered hydrogel's antiwear properties are confirmed by using a knee simulator, following ISO 14243. Finally, in vitro tests with human chondrocytes confirm the absence of cytotoxicity effects. The results shown in this paper open the way to a multilayered synthetic injectable or surgically implantable filler for restoring AC defects. Abstract : Bilayered hydrogel made of gellan gum and poly(ethylene glycol)diacrylate reproduces the mechanical and lubrication features of articular knee cartilage, mimicking their superficial/deep zones. Graphene oxide dopant improves the superficial layer's lubrication. Bilayered hydrogel withstands cyclical stresses simulated by a knee simulator (according to ISO14243) and doesn't show cytotoxic effects. Results open the way to the potential restoration of chondral defects.