Oxygen plasma substrate and specific nanopattern promote early differentiation of HepaRG progenitors.

Fully differentiated HepaRG cells are the hepatic cell line of choice for in vitro work in toxicology and drug trials. They are derived from a hepatoblast-like progenitor (HepaRG-P) that differentiate into a co-culture of hepatocyte-like and cholangiocyte-like cells in the presence of differentiation-inducing chemical dimethylsulfoxide (DMSO). This process requires 2 weeks of proliferation and differentiation and can be time consuming and costly. Identifying a chemical free method to push HepaRG-Ps towards a mature lineage would save both time and money. It has been shown, that tissue culture substrates play an important role in the development and maturity of a cell line, and this is particularly important for progenitor cells, which retain some form of plasticity. Oxygen plasma treatment is used extensively to modify cell culture substrates, and there is evidence that patterned rather than planar surfaces have a positive effect on proliferation and differentiation. In this study, we compared the effect of standard tissue culture plastic (TCP), oxygen plasma treated (OPC), and nanopatterned surfaces (NPS) on early differentiation and functionality of HepaRG-P cells. Since NPS were oxygen plasma treated we initially compared the effect of TCP and OPC to enable comparison between all 3 culture surfaces using OPC as control to asses if patterning could further enhance early differentiation and functionality. The results show that cells grown on OPC substrate exhibited earlier differentiation, proliferation and function of HepaRG-P's compared to TCP in the absence of DMSO. Culturing these cells on OPC with the addition of NPS did not confer any additional advantage. In conclusion, OPC surface appeared to enhance hepatic differentiation and functionality and could replace traditional methods of differentiating HepaRG-P cells into fully differentiated and functional HepaRGs earlier than traditional methods.