Table 3.

Summary of three dimensional (3D) bioprinting where non-covalent crosslinking other than electrostatic interaction, was employed showing materials used, type of biomolecules and targeted tissues. Various biomaterials have been used alone or in combination, such as alginate (Alg), prolinated alginate (P-Alg), polycaprolactone (PCL), glycinamide (Gly), Silica nanoparticle (SN), silk fibroin (SF), polyethylene oxide (PEO), polyvinyl alcohol (PVA), polyethylene glycol (PEG). Cells used included human mesenchymal stem cells (HMSCs), human induced pluripotent stem cells (HIPSCs), chondrocytes cells (CCs) murine preosteoblasts (MPs), and epidermal stem cells (ESCs).

Biomaterial	Crosslinking Method	Printing Technique	Cell Type	Targeted tissue	Ref.
Gly/Clay	Hydrogen bonding	extrusion	MPs	Bone Regeneration	[27]
PVA/ Phytagel	Hydrogen bonding	extrusion	ESCs	Soft Tissue Phantoms	[81]
P-Alg	Hydrogen binding + Ionic-Cacl2	extrusion	HIPSCs	Not specified	[208]
SN-PCL	Hydrogen binding + π–π stacking	Inkjet bioprinting	CCs	Not specified	[209]
PCL-Pyrimidinone	Hydrogen binding + UV crosslinking	stereolithography	Not specified	Not specified	[210]
SF/PEG	Hydrophobic interactions	extrusion	HMSCs	Not specified	[29]
Polypeptide/DNA	DNA hybridization	extrusion	HIPSCs	Not specified	[211]
Polypeptide/DNA	DNA hybridization	extrusion	HIPSCs	Not specified	[83]