Liver

CELLINK HEP X for liver tissue models

The liver is responsible for metabolizing various compounds for distribution and activation. The use of 3D bioprinting technology and materials – bioprinters and bioinks- can advance the mimicry of the complex architecture of the cellular organization, vascular branches, and bile canaliculi network. By providing drug metabolism, 3D bioprinted liver tissue models can become the essential platform for drug development.

Aim

The aim of this project is to investigate HEP X bioink for liver tissue models using human liver cell lines and primary human liver cells. The first aim is to demonstrate that HEP X can be used to bioprinted HepG2 (hepatocyte cell line) and LX2 (stellate cell line) in co-culture. The second is to demonstrate that HEP X can be used for primary human hepatocyte and stellate cells to 3D bioprint liver models.

 

CELLINK Products Used

  • CELLINK HEP X
  • BIO X

Co-Culture

In our labs, we demonstrated that HepG2 and LX2 bioprinted as a 2:1 co-culture can be cultured for up to 21 days. The optimization of cell density for liver tissue modelling was performed with 10 or 30 million cells per ml of HEP X. Fluorescent microscopy images (taken at 10x) with Live/Dead staining demonstrates cell proliferation, stretched cell morphology, and cell-cell contact. With 21 days of culture, the 10 million cell density demonstrates cellular networks within the 3D construct while the 30 million cell density demonstrates complete cell coverage. Hence, depending on the question of interest, cell density can be a parameter during co-culture and long-term experiments.

3D Bioprinted Primary Hepatocytes

For clinical relevancy, we also demonstrated 3D bioprinting of primary human hepatocytes for generation of in vitro assay models for drug development.

Human primary hepatocytes are sensitive cells, however within the HEP X bioink, the cells can survive 3D bioprinting. Hepatocyte (yellow) clustering was observed for up to 21 days of culture with multiphoton imaging. Scale bars 100 µm or 25 µm as indicated.

3D Bioprinted Primary Stellate Cells

Studies on human primary stellate cells are essential for understanding liver matrix production. After 3D bioprinting in HEP X, stellate cells maintain their morphological characteristics which can be shown as tunnelling and branching out in bright field image beside. The live/dead staining image beside, demonstrates more in details the tunneling in 3D. Scale bars 100 µm.

Conclusion

At CELLINK, we demonstrate that co-culture or single culture of major liver cell types, such as hepatocytes and stellate cells, can be successfully 3D bioprinted using our human liver ECM-based HEP X bioink. Liver ECM components help to mimic the natural liver lobule environment in order to maintain and improve specific cell functions. In addition, HEP X will provide a favourable environment for the use of primary hepatocytes, stellate cells, and non-parenchymal cells as a drug development platform.