TABLE 1.
Summary of the main features of currently available 3D printing/bioprinting techniques.
| Technology | Production method | Production principle | Features | Limitations | References |
|---|---|---|---|---|---|
| Inkjet | Drop-on-demand | - Thermal | - High printing resolution (20–100 μm) | - thermal and mechanical stresses | Borovjagin et al. (2017), Jang et al. (2017), Cui et al. (2018), Alonzo et al. (2019), Gardin et al. (2020), Wang et al. (2021b), Kozaniti et al. (2021), Ghofrani et al. (2022) |
| - Piezoelectric | - Up to 30 k cells per drop, up to 1,000 drops/s | - inks are not processable | |||
| - Minor effects on cells | - limited printed cell density | ||||
| Extrusion Based Printing | Material filament extrusion | - Mechanical (screw-based) | - cell densities close to physiological human CMs values | - Bioink viscosity is a critical parameter | Borovjagin et al. (2017), Jang et al. (2017), Cui et al. (2018), Roy et al. (2018), Alonzo et al. (2019), Wang et al. (2021b), Ghofrani et al. (2022) |
| - Pneumatic | - Modest resolution (100 μm) | ||||
| - High shear-stress | |||||
| FRESH | Extrusion in a support bath | A Bingham-like behaving medium supports the printed contructs | - Addresses the poor mechanical properties exhibited by many interesting hydrogels | - Caution is required for delicate structures or cell-laden hydrogels | Madden et al. (2010), Hinton et al. (2015), Wang et al. (2021b) |
| Laser Assisted Printing | Laser radiation mediates either the extrusion of biomaterials of their crosslinking | - Laser pulse–mediated expulsion of ink from bi-layer metal slide (LIFT) | LIFT | LIFT | Gaebel et al. (2011), Verheugt (2015), Borovjagin et al. (2017), Jang et al. (2017), Roy et al. (2018), Alonzo et al. (2019), Ghofrani et al. (2022) |
| - Laser-based crosslinking (MPP) | - high resolution (∼20 μm) and high-speed (ejection frequency up to 5 kHz) printing systems | - not commercially available | |||
| - cell density up to 108 cells/mL | - High cost (200 k$) | ||||
| - prints any biomaterial with viscosity ranging from 1 to 400 mPa s | - Careful optimization of various parameters (i.e., bioink viscosity, crosslinking/gelation kinetics of the collector and laser parameters) is required | ||||
| - up to a single cell per pulse | MPP | ||||
| - High CMs viability (>90%) | - macro-scale products are difficult to obtain | ||||
| MPP | |||||
| - ability to print (crosslink) soluble and structural ECM proteins | |||||
| - can print details from 3μm to 300 nm | |||||
| UV-based printing | UV-crosslinking of light sensitive materials | -Beam-scanning (spot by spot) | - can process various biomaterials in a wide range of viscosities (1–2000 mPa s) | - high cost | Lin et al. (2013a), Kim et al. (2014), Borovjagin et al. (2017), Jang et al. (2017), Cui et al. (2018), Izadifar et al. (2018), Roy et al. (2018), Alonzo et al. (2019), Liu et al. (2020), Wang et al. (2021b), Kozaniti et al. (2021), Ghofrani et al. (2022) |
| - Mask projection (one whole layer at a time) (DLP) | - accuracy in cell placement and optimised survival | - long printing time (resolvable with DLP) | |||
| - able to process nanocomposite bioinks or create micro- or nanopatterned surfaces | - difficulty to implement multi-material strategies | ||||
| - the mechanical strength of the printed product may present inhomogeneities | |||||
| Melt Electrospinning Writing | Voltage powered technique used to produce 3D micro-fibrous scaffolds | Consists of a polymer loaded spinneret, positively charged with respect to a collector plate able to move in the x-y plane | - precisely defined scaffolds | - Voltage, syringe diameter and distance between syringe and plate need to be precisely controlled | Castilho et al. (2018), Olvera et al. (2020), Ghofrani et al. (2022), Ainsworth et al. (2023) |
| - can process polymers that are not dissolvable in any solvent | |||||
| - can be used to produce structures with adequate properties for cardiac cells (mechanical anisotropy and electroconductivity) |