Nanocomposite hydrogels of agarose/nanosilicates for 3D bioprinting applications

Development of the biofabrication technologies is mainly hindered by the lack of bioinks which satisfy the criteria for both bioprinting and tissue engineering. Hydrogels as bioinks, are the main cell carrier in the process of bioprinting. However, the adaptation of physio-chemical properties of hydrogel bioinks to the specific requirements of 3D bioprinting process demands selection criteria which includes the biological activity of bioinks as well as mechanical and structural stability throughout the process. Natural hydrogels usually do not comply with the process of bioprinting in terms of crosslinking conditions, mechanical stability, and flow properties. To overcome the major drawbacks of natural hydrogel in adaptation with 3D bioprinting process, synergistic tuning of bioactivity and flow properties by synthesis of nanocomposite hydrogels was introduced. Agarose as a naturally derived polysaccharide has been mostly used as the support structure in 3D bioprinting. Although agarose hydrogels show high viscosity and shape fidelity after extrusion, they lack the necessary cell binding sites in their backbone and thus have limited bioactivity. Additionally, the thermal crosslinking mechanism of gelation in agarose is not compatible with extrusion 3D bioprinting. Laponite nanosilicates showed to be an effective additive being able to induce noteworthy effects on flow behavior and bioactivity of hydrogel matrix. The promising effects of incorporation of Laponite in different hydrogel matrices suggests its potential in improvement of flow behavior and bioactivity of agarose hydrogels to meet the criteria for extrusion 3D bioprinting. We hypothesized that inclusion of Laponite nanosilicates within agarose hydrogels will improve the bioactivity of the hydrogel, while the flow behavior of agarose can be altered at the same time to adapt with the extrusion 3D bioprinting.