Table 1.
Properties of different hydrogels used in 3D bioprinting.
| Hydrogel | Applied Material Oncentration (w/v) |
Mechanical Roperties a |
Viscosity (Pa/s) |
Gelation Method b |
Bioprinting Technique c | Cell type Density Cells/mL d |
Cytocompatibility /Biodegradability |
Refs. |
|---|---|---|---|---|---|---|---|---|
| Alginate | Alginate/Ca2+ 1%–3%/0.5% | Elastic modulus λ = 21.35 kPa |
2.9 at a shear rate of 91 s−1 | IC | Inject | RHECs 500,000 | 83%/yes | [44,45] |
| Sodium alginate 1% | - | 0.12 shear rate not reported | IC | Laser-assisted | HUEVCs (Eahy926), 6 × 107 and Rabbit carcinoma cells (B16) 4 × 107 | High, day 1/- | [46] | |
| Gelatin | Methacrylate GelMA/gelatin 5%/8% | Young’s modulus Y = 4.85 ± 0.41 kPa | 10−100 at a shear rate of 1–500 s−1 | PC | EB | BMSCs 5.0 × 106 | <90%/yes | [47] |
| GelMA/alginate/4-arm PEGTA 5%–7%/1%–3%/1%–3% | Compressive moduli = 24.2–50.7 kPa | 28−54 at a shear rate of 7.74 s−1
0.08 Pa s−1 |
PC | Inject | HUVECs MSCs 3 × 106 |
80%–90%, day 7/yes | [48] | |
| GelMA/alginate/Ca2+
4.5%/1%–4%/0.3–0.6 M |
λ = 15 – 55 kPa | 0.08 shear rate not reported | PC/IC | EB | HUVECs- | 75%, day 5/- | [49] | |
| GelMA/GelSH & heparin 10%/1% | Compressive moduli = 1 ± 2 kPa | - | Thiol-ene | - | Human articular chondrocytes 15 × 106 |
74%–86%, week 5/- | [50] | |
| Poly (ethylene glycol) |
Dimethacrylate 10%; 20% | Compressive moduli = 395.73 ± 80.40 kPa | - | PC | Inject | Human articular chondrocytes 5 × 106 |
89%, day 1/- | [51] |
| Diacrylate/alginate 20%/12.5% | λ = 5.3 ± 0.9 to 74.6 ± 1.5 kPa | - | PC | EB | PAVIC 20 × 106 | ca. 100%, day 21/- | [52] | |
| Hyaluron-ic acid (HA) |
Methacrylate (HA-MA)/GelMA 1.5%/- | Storage modulus G′ = 80–90 Pa Loss modulus G″ = 40 Pa |
- | PC | Inject | HepG2 C3A Int-407 NIH 3T3 2.5 × 105 |
Cell proliferation p < 0.05/yes |
[53] |
| Gelatin-methacrylamide/HA 20%/2.4% | Compressive modulus = 7995 kPa | - | PC | Inject | Chondrocytes 5 × 106 |
82% ± 8%, day 3/yes | [54] | |
| HA/hydroxyethyl-methacrylate derivatized-dextran (dex-HEMA) 2%–6%/10% | G′ = 10 kPa | 70 at a shear rate of 0.1 s−1 and >10 at a shear rate <10 s−1 for 2% HA and 10% DexHEMA | PC | EB | Chondrocytes- | 75%±19%, day 3/yes | [55] | |
| PEG-tetraacrylate/yaluronic acid 3%–5%/1.5%–2.5% |
G′ = 100–800 Pa | - | Michael addition | Microcapillary tube-style printing | NIH 3T3; HepG2 C3A; Int 407 25 × 106 |
ca. 100%, week 4/yes | [56] | |
| HA/methyl cellulose 0.25%–2.0%/0.5%–9% |
G′ = 10–1000 Pa | - | Thermal | EB | MSCs- | 75%, day 15/- | [57] | |
| Hyaluronic acid hydrogels grafted with laminin- | - | - | PC | Photopatterned layer-by-layer | Schwann cells- | Cells retained at 36 h/yes (enzymatically) | [58] | |
| p(HPMAm-lac)-PEG-p(HPMAm-lac) | 25%–35% | λ = 119 kPa | - | Thermal/PC | EB | Chondrocytes 5.0 × 106 |
94%, day 1/yes | [59] |
| Polycaprolactone (PCL) |
PCL with gelatin/PEGDA- | Y = 1.43 ± 0.33 mPa | - | PC | Stereolithography and electrospinning | NE-4C NSCs - | Enhancement in cell proliferation, day 5/- |
[60] |
| Polyurethane | Polyurethane with PCL 25%–30% | G′ = 680–4000 Pa | - | Supramolecular (hydrogen bonding) | Fused-deposition manufacturing | NSCs 4 × 106 | ca. 100%, day 3/yes | [61] |
a Storage modulus = G′; loss modulus = G″; b Ionic crosslinking = IC; photocrosslinking = PC; c Extrusion-based = EB; d Rat heart endothelial cells = RHECS; bone marrow stem cells = BMSCs; human umbilical vein endothelial cells = HUVECs; human mesenchymal stem cells = MSCs; porcine aortic valve interstitial cells = PAVICs; human hepatoma cells = HepG2 C3A; human intestinal epithelial cells = Int-407; murine fibroblasts = NIH 3T3; neural stem cells = NSCs.