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International Journal of Bioprinting New challenges in liver tissue engineering

Table 1. (Continued...)
Heparin Michael-type addition Rat hepatocytes – Heparin hydrogel allowed encapsulation and culture of 101
reaction (thiol and hepatocytes (single cells or spheroids) with and without
diacrylate) HGF for 20 days.
– Hepatocyte spheroids exhibited high levels of albumin and
urea synthesis with increased hepatic function over time;
single cells showed gradual loss of hepatic function.
– Inclusion of HGF into the hydrogel reversed the loss of
function in single hepatocytes and enhanced hepatic
phenotype of spheroids.
HA-Col UV-light/ hyaluronic HepG2 – Col provided adhesion, fibrous network structure and 86
acid methacrylated, viscoelastic mechanical basis. HA simulated ECM
imine bonds (HA- composition and provided rigidity. Imine bonds adjusted
Col) and physical the viscoelasticity of the hydrogel.
crosslinking (Col) – Hydrogel Young’s modulus was 2.5 kPa, and the half
relaxation time (τ ) was 50 s, representing viscoelastic
1/2
property of the hydrogel.
– HepG2 cells proliferated and typically tend to cluster in
hydrogels.
– The in vitro system was useful to study alcoholic liver
disease.
HA-Gel PEGDA/thiolated HA HepaRG – Cells formed spheroids within the hydrogels, being better 103
and Gel organized in the case of low cell density encapsulation than
in high density.
– Low- and high-cell-density encapsulation in 3D showed
good viability.
– Cells showed differentiation towards hepatocyte phenotype
in hydrogels after 2 weeks of culture.
Pullulan-dextran Sodium HepaRG – Microindentation showed that hydrogel mimics the 117
trimetaphosphate/ mechanical properties of healthy liver.
ionic – HepaRG cells exhibited long term viability when cultured
for 21 days within the hydrogel.
– Cells within the hydrogel displayed typical functions of
mature hepatocytes: urea production, albumin synthesis,
CYP450 activity, glycogen storage, bile acids transport, and
excretion system.
Synthetic hydrogels
PEG diacrylamide- UV-light Rat hepatocytes, J2- – 85% of MMP-sensitive peptide reacted with the PEG 104
peptide 3T3 fibroblasts, and a diacrylamide and hydrogel degraded with collagenase,
liver endothelial cell being stable for several weeks in aqueous environments.
(LEC) line – Hepatocytes-embedded hydrogels produced albumin and
secreted urea for at least 15 days of culture.
– Co-culture of hepatocytes with LEC allowed the
preservation of hepatic-specific function for at least 3 weeks
of culture.
PEG glycol diacrylate UV-light Bipotential mouse – Pre-aggregated bipotential embryonic cells showed a 105
(RGD or RGE peptide embryonic liver cells significant increase in viability compared to dispersed cells.
functionalized) and rat hepatoctytes – Differentiation occurred within the PEG hydrogels
co-cultured with (albumin and alcohol dehydrogenase gene expression).
fibroblasts – Fibroblasts co-culture with rat hepatocytes helped to
maintain the hepatocyte function within PEG hydrogels.
– Conjugation of hydrogels with RGD adhesion peptides
improved hepatocyte functionality.
(Continued...)

Volume 10 Issue 3 (2024) 123 doi: 10.36922/ijb.2706