Printable gelatin, alginate and boron nitride nanotubes hydrogel-based ink for 3D bioprinting and tissue engineering applications

Hydrogels comprised of alginate and gelatin are potential biomaterials for extrusion-based bioprinting. However, existing polymeric inks are inadequate in printability, shape fidelity and mechanical properties that desire to produce scaffold using 3D bioprinting. Here, a novel printable hydrogel-based ink solution comprised of gelatin-alginate (GA) reinforced by boron nitride nanotubes (BNNTs) was developed for 3D bioprinting and tissue engineering applications. The ink solutions were tested for printability, printing accuracy, compressive behaviour, while the printed scaffolds were tested for their viability of human embryonic kidney cells (HEK293T). Printability tests showed the strand thicknesses decreased with the increasing concentration of BNNTs in the GA ink solutions. Similarly, the printing accuracy increased (>90%) with the increasing loading of BNNTs. However, the swelling rate of the GA scaffold was higher than BNNTs reinforced GA scaffolds. Mechanical properties were measured by using compression testing. Increasing BNNTs concentration in GA resulted in a higher load of compressive stress. Also, a quantitative analysis of the cell viability of scaffolds revealed a slight effect on toxicity with the increased doping of BNNTs. Hence, the relevant data on BNNTs reinforced GA scaffold indicated that it could be a potential ink solution for tissue engineering applications through 3D bioprinting processes. (c) 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).