International Journal of Stem Cells

Table. 3. Table 3

A summary of undifferentiated induced pluripotent stem cell bioprinting

Printing technique	Nozzle diameter (μm)	Bioink	Crosslinker	Construct design	Cell concentration (cells/ml)	Characterization	Reference
Extrusion	101.6	1.5% w/v alginate	600 mM CaCl₂	Ring structure	1×10⁶	Pluripotency: flow cytometry (OCT3/4, SSEA4)	(59)
	40	Geltrex^TM	-	100 nl droplet	4.5×10⁶	Pluripotency: immunostaining (TRA-1-81), qRT-PCR (NANOG)	(82)
	40	Geltrex^TM	-	100 nl droplet	4.5×10⁶	Spontaneous differentiation: qRT-PCR (PAX3, HAND1, SOX-17)	(82)
	200	5% w/v alginate, 5% w/v carboxymethyl-chitosan, 1.5% w/v agarose	2% CaCl₂ for 10 min	Grid structure	8×10⁷	Proliferation: PrestoBlue assay	(83)
						Pluripotency: flow cytometry (OCT4, SOX2, TRA-1-60, SSEA4), immunostaining (OCT4, SOX2, SSEA4, TRA-1-60)
						Spontaneous differentiation: qRT-PCR (H19, PDX1, HAND1, IGF2, NES, TUBB3)
						Directed neural differentiation: immunostaining (PAX6, NES, MAP2, GFAP, TUBB3, SYP, GABA), qRT-PCR (NES, TUBB3, GFAP, GABA, NKX2-1, PET1, OLIG2)
	300	NFC alginate (60 : 40), NFC with hyaluronic acid	100 mM CaCl₂, 0.001% H₂O₂	Grid structure	2×10⁷	Pluripotency: immunostaining (OCT4)	(84)
						Spontaneous differentiation: qRT-PCR (SOX9, ACAN, Coll 2A1)
						Directed chondrogenic differentiation: Alcian blue-van Gieson staining (GAG), Safranin-O staining, immunostaining (Collagen type II)
	260	2% w/v hydroxypropyl chitin (HPCH), 0%∼30% Matrigel^TM	Temperature 37℃	Grid structure	1×10⁶	Proliferation: Cell Counting Kit-8 assay	(72)
	260	2% w/v hydroxypropyl chitin (HPCH), 0%∼30% Matrigel^TM	Temperature 37℃	Grid structure	1×10⁶	Pluripotency: AP staining, immunostaining (OCT4, SSEA4), flow cytometry (OCT4, SSEA4), qRT-PCR (OCT4, NANOG)	(72)
	260	4% w/w alginate, 1% w/w polyethylene glycol fibrinogen	0.3 M CaCl₂, 365 nm UV for 5 min	Grid structure	8×10⁶	Proliferation: immunostaining (Ki67)	(49)
	260	4% w/w alginate, 1% w/w polyethylene glycol fibrinogen	0.3 M CaCl₂, 365 nm UV for 5 min	Grid structure	8×10⁶	Pluripotency: qRT-PCR (OCT4, SOX2, NANOG), immunostaining (OCT4)	(49)
	210	10% gelatin methacrylate, fibronectin, laminin-111, collagen methacrylate	405 nm flashlight for 20 sec	Human chambered muscle pumps	1.5×10⁷	Proliferation: immunostaining (Ki67)	(81)
	210		405 nm flashlight for 20 sec	Human chambered muscle pumps	1.5×10⁷	Directed cardiac differentiation: immunostaining (cTnT, TUNEL, αSMA, CD31, CX43, Bin1, RYR2, SERCA2, α-actin, cTnI)	(81)
Laser	N/A	1 wt% hyaluronic acid, Matrigel^TM	N/A	0.01∼1 nl droplets	3.3×10⁷	Proliferation: LDH activity assay, Tripan blue staining, MTT assay, immunostaining (Ki67)	(85)
						Pluripotency: ALP assay, immunostaining (OCT3/4, NANOG, ALP, SSEA4)
						Spontaneous differentiation: immunostaining (βIII Tubulin, Cytokeratin 8, AFP, SMA, von Willebrand factor, α-actinin)
						Directed cardiac differentiation: immunostaining (Brachyury, cTnT, NKX2.5, α-actinin)

N/A: not available, NFC: nanofibrilated cellulose, UV: ultraviolet.

International Journal of Stem Cells 2024;17:38-50 https://doi.org/10.15283/ijsc23146