Nora Kammer's paper in Artificial Organs on "Labelling of primary human hepatocytes with micron-sized iron oxide particles in suspension culture suitable for large-scale preparation" is available pre-print. Co-authors are Nils Billecke, Mehmet H. Morgul, Michaela K. Adonopoulou, Martina Mogl, Mao D. Huang, Stefan Florek, Katharina R. L. Schmitt, Nathanael Raschzok and Igor M. Sauer.
Protocols for labelling of hepatocytes with micron-sized iron oxide particles (MPIO) in adhesion culture enable cell detection using clinical Magnetic Resonance equipment. For clinical applications, large numbers of cells must be labelled in a simple and rapid manner, which requires new labelling protocols. The aim of this study was to investigate the feasibility of preparing MPIO-labelled primary human hepatocytes in a temporary suspension culture. Human hepatocytes were isolated from 16 donors and labelled with MPIO in suspension, using the Rotary Cell Culture System. Particle incorporation was investigated by light and electron microscopy. Cells were compared to adhesion culture-labelled and subsequently enzymatically resuspended cells. During a five-day culture period, hepatocyte-specific parameters of cell damage (aspartate aminotransferase and alanine aminotransferase) and metabolic activity (urea and albumin) were analysed. Suspension cultures showed a higher outcome in cell recovery compared to the conventional labelling method. When incubated with 180 particles/cell for four hours, the mean particle uptake was 28.8 particles/cell at a labelling efficiency of 95.1%. Labelling in suspension had no adverse effects on cell integrity or metabolic activity. In conclusion, labelling in suspension is a practicable method for fast and efficient preparation of large numbers of labelled cells that are suitable for clinical applications.