The effect of extended transportation time on the quality of freshly isolated human liver cells

Introduction: Given that the liver carries out a wide range of functions, such as detoxification, metabolism and homeostasis, isolated hepatocytes are important in vitro models for research questions to do with pharmacokinetics, toxicology etc. In particular, the use of human hepatocytes is important for the validation of studies done with animal models and for translational research. However, generally speaking, it is difficult for an individual researcher to isolate hepatocytes himself for experimentation due to the large amount of manpower required. This manpower is required to collect the donated remnant livers with informed consent according to ethical regulations, carry out serological tests and to isolate liver cells when tissue is made available by surgeries. Thus, core facilities that isolate human liver cells for provision to research groups are essential. Since liver cell quality is paramount for relevant results, this study aims to examine if extended transportation time affects the quality of isolated human liver cells.

Methods: Human hepatocytes were isolated by a modified two-step collagenase perfusion technique with modifications. The viability of the isolated hepatocytes (N= 60) was assessed immediately after isolation and after being stored for 17h in Cold Storage Solution (CSS) on ice. These results were compared to counts from actual shipments of hepatocytes (N= 111) overnight on ice to collaborators. For a number of isolations, adherence to cell culture plates and confluence of hepatocytes was also assessed after storage on ice for 18h.

Results: After 17h storage on ice, viability dropped significantly from 78 ± 0.9% to 66 ± 1.7%. For the shipped samples, viability dropped significantly from 79 ± 0.5% to 67 ± 1.9%. Thus, for both scenarios, hepatocytes dropped approximately 12% in viability. Although, there is a drop in viability, the hepatocytes were able to adhere to cell culture plates with good confluence up to 3 days when a similar number of viable cells were plated.

Discussion: In conclusion, there was a small drop in hepatocyte viability when cells were stored overnight on ice in CSS. After the drop in viability, the cells still had an average viability of 66%, which is high enough for downstream experiments. These cells were still able to adhere well to culture plates with a good confluence for further experiments. Thus, these results indicate that hepatocytes can indeed be successfully transported overnight and shows that a distribution system using core facilities to support a large number of research laboratories functions well.

Corresponding author: Lee, Serene M. L.

E-Mail: [e-mail]