3D Bioprintable Gt-Alg-MMT Nano Bioink for Cartilage Tissue Engineering.

Damage to articular cartilage is irreversible, and its self-healing ability is minimal. The construction of articular cartilage in tissue engineering requires suitable biomaterials as scaffolds to provide a 3D natural microenvironment for the development and growth of articular cartilage. This study aims to explore the feasibility of Gt-Alg-MMT (gelatin/sodium alginate/montmorillonite) nanocomposite hydrogel as a 3D printing bioink and its applicability in 3D printing cartilage scaffolds. The optimization results showed that the bioink with the ratio of 2Gt-5Alg-5MMT had the best 3D printability and mechanical strength, and the optimal 3D printing pressure and printing speed were 0.29 MPa and 2.5 mm/s, respectively. The performance test showed that the 3D printed 2Gt-5Alg-5MMT scaffold has a honeycomb porous network structure, with porosity and water content of more than 90%, static compressive elastic modulus of 125 ± 9.6 kPa, hysteresis of cyclic compression of 60%-80%, and has viscoelasticity, structural stability, and thermal stability close to cartilage tissue in three scanning modes of dynamic strain, dynamic frequency, and dynamic temperature. In addition, Live/Dead staining experiments showed that the 2Gt-5Alg-5MMT scaffold has excellent biocompatibility with ADTC5 cells. Therefore, this 3D-printed 2Gt-5Alg-5MMT scaffold is expected to be a candidate material for promoting articular cartilage regeneration.