Table 1.
Comparison of 3D printing technologies for bioartificial organ manufacturing.
| 3D Printing Technique | Working Principle | Bioinks | Cell Density | Cell Viability | Printing Speed | Resolution | Cost | Advantages | Disadvantages | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|
| Inkjet-based 3D printing | Using thermal or acoustic force to eject very small size ‘bioink’ drops onto a substrate | Thermosensitive hydrogels (e.g., PEG) and some nature polymers (e.g., alginate collagen, fibrinogen) with viscosity of 3.5–12 mPa/s | Low (<1 × 106 cells/mL) |
85% | Fast (1–10,000 droplets/s) | High (≈50 μm) | Low | Low cost; high printing resolution; low viscosity; fast printing speed | Poor mechanical properties; poor cell sedimentation effects; low cell densities | [84,85,86] |
| Fusion deposition modeling (FDM) | Molten thermoplastic materials through one or more heated extrusion heads with a small orifice in a specific lay-down pattern | Thermoplastic materials (e.g., PCL, PLA, PVA, ABS, TPU) with viscosity of 30 mPa/s to >6 × 107 mPa/s | None | None | Slow (200 μm–10 mm/s) | Low (100 μm to 1 mm | Medium | Low cost; a wide range of materials; excellent mechanical properties | Only applicable for thermoplastic materials; high temperature; cannot incorporate cells, growth factors, and other bioactive agents | [87,88] |
| Extrusion-based 3D printing | Biomaterials are extruded though one or more nozzles under controlled pressure in a layer-by-layer pattern | Most nature polymers and some synthetic polymers (e.g., alginate, gelatin, collagen, PEG, PLGA, PU) with viscosity of 30 mPa/s to >6 × 107 mPa/s | High (>1 × 108 cells/mL) |
40%–100% | Medium (5–20 mm/s) | Medium (10–100 μm) | Low | High cell densities; high cell viability; various printing materials; flexible geometric shapes | Only applicable for viscous hydrogels; moderate resolution | [89,90,91,92,93] |
| Stereolithography (SLA) | A solid freeform, nozzle-free technology based on photosensitive polymer formulation under laser beam | Photopolymers | Medium (<1 × 108 cells/mL) |
90% | Fast (normally 30–45 min) | High (100 μm) | Low | High printing resolution; fast printing speed; difficult to print multiple cell types | Cytotoxicity of the laser beam and photoinitiators; additional post-curing process may be necessary to remove the unpolymerized liquid resin; poor cell deposition effects | [46,94,95] |
| Digital light processing (DLP) | A solid freeform, nozzle-free technology based on photosensitive polymer formulation under laser beam | Photopolymers | Medium (<1 × 108 cells/mL) |
90% | Higher than SLA (10–50 μm) | Higher than SLA (10–50 μm) | Low | High printing resolution; fast printing speed; difficult to print multiple cell types | Cytotoxicity of the laser beam and photoinitiators; additional post-curing process may be necessary to remove the unpolymerized liquid resin; poor cell deposition effects | [96,97] |
| Laser-based 3D printing | Laser pulse generates a high-pressure bubble towards the collector substrate | Nature polymers (e.g., alginate, gelatin, fibrinogen) and some synthetic polymers (e.g., PCL, PLGA) with viscosity of 1–300 mPa/s | Medium (≈1 × 108 cells/mL) |
90%–95% | High (10–40 μm) | High (10–40 μm) | High | High printing resolution; wide range of printable viscosity; moderate cell viability | High printing resolution; wide range of printable viscosity; moderate cell viability | [98,99,100] |