The first three-dimensional miniature model of the human placenta has been created from stem cells.
The model, or organoid, is the closest-yet mimic for the structure and gene expression of the early placenta. The organoids are to be used to investigate conditions during pregnancy, such as preeclampsia and intrauterine growth restriction.
'No organoid system for the human placenta was available before,' Dr Martin Knöfler of the Medical University of Vienna, who led the research team, told Labiotech.eu.
The organoid was made up of stem cells taken from the inner layer of the trophoblast, the layer of cells that forms the origin for the placenta. Only two-dimensional models of the placenta had been created from trophoblast cells previously. Ordinarily, these cells lose their ability to divide and proliferate when kept in a dish. As such, scientists have not been able to use them to investigate the placenta thoroughly.
However, a cocktail of growth factors and molecules to control signalling between cells – which had worked for developing organoids of gut tissue – turned out to work for the placenta too. The three-dimensional organoids developed by Dr Knöfler measured less than half a millimetre across, but showed very similar gene expression and cellular and tissue structure to the early placenta.
The organoids were also self-renewing, with the stem cells present continuing to grow and develop into new tissue. In addition, the organoids could be frozen and cultivated again at a later date, the researchers reported.
'The fact that there [had been] no self-renewing cell culture model systems available for the human placenta made it difficult, if not impossible, to study the causes of malfunctions [in pregnancy],' said Dr Knöfler. 'Establishment of the placenta organoid system will improve this situation significantly and will help advancing drug development and consequently medical treatments for dangerous gestational disorders.'
The paper was published in the journal Stem Cell Reports.