Formulation of chitosan and chitosan-nanoHAp bioinks and investigation of printability with optimized bioprinting parameters.

The development of a chitosan-based bioink that can provide a cell-friendly environment at relatively low concentration and moderate cross-linking conditions is still problematic. Here, we developed amorphous nanohydroxyapatite (nHAp) containing chitosan bioink formulations that can be gelled via the inclusion of glycerol phosphate (GP) and sodium hydrogen carbonate (SHC) into the polymer network under physiological conditions. Rheological analyses indicated that all the formulations showed shear-thinning characteristics compatible with the extrusion-based bioprinting.