TABLE I.

Biomechanical properties of typical hydrogel bioinks pre, during, and post 3D bioprinting and their applications.

Bioink materials	Solvents used for bioinks	Rheological performance	Mechanical stiffness (modulus)	3D bioprinting applications	References
Alginate	0.9% NaCl; calcium free culture medium	Non-Newtonian shear thinning, described by a power law model	1.17–12.53 kPa	Schwann cells; human mesenchymal stem cells	46–48
Alginate and gelatin	Culture medium	Embedded printing; loss tangent between 0.25 and 0.45	54.6–64.1 kPa	Fibroblasts	49 and 50
Alginate, fibrin, and hyaluronic acid	0.9% NaCl	Shear thinning, cross-linking bath	1.28–2.61 kPa	Schwann cells and neurons	43 and 51
Oxidized alginate and gelatin	Water; PBS; culture medium	Loss tangent between 0.24 and 0.28	3–9.2 kPa	Endothelial cells; human adipose-derived mesenchymal stem cells	32 and 52
Chitosan-based hydrogel	Phosphate buffered saline (PBS)	Semi-solid under temperature control; shear thinning	1.59–300 kPa	Human adipose-derived mesenchymal stem cells; chondrocytes	53–55
Hyaluronic acid-based hydrogel	PBS	Shear thinning and self-healing	15.7–20.8 kPa	Fibroblasts	56
Poly(ethylene glycol) diacrylate (PEGDA) and gellan gum	PBS	Pseudoplastic shear thinning	40–160 kPa	Murine bone marrow stromal cells; mouse osteoblastic cells	57
GelMA	PBS	G′ > G″ by cooling; embedded printing;	5.9–36.4 kPa	Endothelial cells	58 and 59
GelMA and gelatin	Water and culture medium	G′ > G″; shear thinning	1.67–264.74 kPa	Bone marrow stem cells	60
GelMA and Hyaluronic acid methacrylate (HAMA)	PBS	G′ > G″; shear thinning	25–155 kPa	Osteocyte cells	61
GelMA and gellan gum	PBS	High yield stress with shearing thinning in a large temperature range	2.7–186 kPa	Equine chondrocytes	62
GelMA and methylcellulose	Na2SO4 solution	High yield stress	∼15 kPa	Human primary osteoblasts	63
GelMA and Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)	Cell culture medium	Strong shear thinning at 25 °C	40–120 kPa	Mouse myoblast cells	64
Collagen and agarose	Acetic acid solution	Improved viscosity, shear thinning	∼18.1 kPa	Corneal stromal keratocytes	65
Collagen and pluronic	Acetic acid solution	G′ > G″ by cooling	0.03–6.98 kPa	Rat bone marrow derived stem cells	66
Fibrin and gelatin	Tris buffered saline; Dulbecco's PBS (DPBS)	Shear thinning	∼9.6 kPa	iPSC-derived cardiomyocytes; human cardiomyocyte cell line; fibroblasts	67 and 68
Silk and gelatin	Culture medium	G′ > G″ by temperature optimization	30–114 kPa	Chondrocytes	69
Decellularized ECM	Culture medium	Embedded printing	0.5–15.74 kPa	iPSC-derived cardiomyocytes; HepG2	70–72