A Synthetic Thermosensitive Hydrogel for Cartilage Bioprinting and Its Biofunctionalization with Polysaccharides

Hydrogels based on triblock copolymers of polyethylene glycol and partially methatrylated poly[N-(2-hydroxypropyl) methatrylainide mono/dilactate] make up an attractive class of biomaterials because of their biodegrad-ability, cytocompatibility, and tunable thermoresponsive and mechanical properties. If these properties are fine-tuned, the hydrogels can be three dimensionally bioprinted, to generate, fot instance constructs for cartilage repair. This study investigated whether hydrogels based on the polymer mentioned above with a 10% degree of methacrylation (M10P10) support cartilage formation by:ichondrocytes and whether the incorporation of methatrylated' Chondroitin sulfate (CSMA),or raethatrylated hyaluronic acid- (HAMA)-can improve the mechanical properties, long-term stability, and printability. Chondrocyte-laden M10P10 hydrogels were cultured for 42 days to evaluate choodrogenesis. M10P10 hydrogels with or-without polysacCharides, were evaluated for their mechanical properties (before and after:I/V-photo-cross-linking), degiadation kinetics, and printability. Extensive cartilage matrix production occurred in M10P10 hydrogels-, highlighting their-potential for cartilage repair strategies. The incorporation,of polysaccharides increased' the.storage modulus of polymer mixtures and decreased the degradation kinetics in cross-linked hydrogels, Addition of HAMA to M10P10 hydrogels improved printability and resulted-in three-dimensional constriiets with excellent cell viability. Hence, this novel combination of M10P10 with HAMA forms an interesting class of hydrogels for cartilage bioprintifig.