**5. Conclusions**

Microextrusion is an excellent 3D bioprinting method that can yield high cell viabilities (≥85%) similar to Inkjet printing using 28G nozzles of either 1/2″ or 1″ lengths for pressures up to 220 psi as long as the hydrogels or solutions are isotonic. Good viability of over 75% can also be achieved using 30G nozzles of 1″ or shorter lengths using 220 psi. Thus, cells can survive with good viability (~85%) under considerable pressure for short periods of time during the microextrusion 3D bioprinting process if they are in isotonic hydrogels.
