GelMA-Xanthan Gum Hydrogel Bioink Preserving hiPSCs Viability and Proliferation

Cardiac tissue engineering is currently investigated with a diversity of biofabrication techniques. In particular, 3D bioprinting makes it possible to develop constructs with an organized distribution of cells. Over the years, a wide variety of materials has been used to create environments that emulate the extracellular matrix. Among these, gelatin methacrylate (GelMA)-based bioinks have widely been studied for extrusion-type 3D bioprinting. Several investigations have shown that GelMA at low concentrations (≤5% w/v) can promote cell viability, although limiting 3D printability, owing to poor retention of shape after extrusion. In this work, a new bioink formulation was developed to improve printability, while maintaining a high cell viability. For this purpose, xanthan gum (XG) was added to GelMA. The composite hydrogel had an elastic modulus of ~9 kPa, comparable to typical values of cardiac tissue. 3D printing tests (without cells) showed the printability of the new hydrogel. Both 2D and 3D cellular adhesion and viability tests showed the hydrogel ability to preserve survival and growth of human induced pluripotent stem cells (hiPSCs).