TABLE 3.

Comparison of the three types of 3-D bioprinting techniques.

	Jetting-based	Extrusion-based	Laser-based
Printer cost	Low	Moderate	High
Biomaterial viscosity	Medium	High	Medium to high
Print speed	Fast (1–10,000 droplets/s)	Slow (10–50 μm/s)	Medium-fast (200–1,600 mm/s)
Cell viability (%)	80%–90%	40%–95%	95%
Resolution	High (up to 50 μm)	Moderate (100 μm to millimeters)	High (10–50 μm)
Cell densities	Low (≤106 cells/ml)	High (cell spheroids)	Medium (≤108 cells/ml)
Quality of vertical structure	Poor	Good	Fair
Advantage	High cell viability; High printing speeds; Low cost; Wide availability; Easy operation	High cell densities; High cell viability; Broad selection of biomaterials; High deposition rates; High print speeds; Anatomically correct porous construct generation	Nozzle free; Fast and accurate fabrication; High resolution; High precision; High cell viabilities
Disadvantage	Low droplet directionality; Nozzle clogging; Limited biomaterials selection; Low cell density and concentration of the ink; Heat and sheer stresses induced damage to cells	Low resolution; Deformation; Encapsulated cell apoptosis; Low cell viability	High cost; Low speed; Low built capability; Possible cytotoxicity; UV induced DNA damage; Low stability and scalability; Limited printing directionality
Tissue engineering application	Blood vessel, bone, cartilage, neuron, liver	Blood vessel, bone, lungs, liver, cartilage, neuron, muscle, ear, skin, lipid bilayers	Blood vessel, bone, skin, adipose, cardiac tissue
References	Irvine and Venkatraman (2016), Roseti et al. (2018), Roseti et al. (2017)	Cole et al. (2009), Hasan et al. (2014), Daly et al. (2016), Pillai et al. (2018), Dhawan et al. (2019)	Roseti et al. (2018), Dhawan et al. (2019), Irvine and Venkatraman (2016)