Donor variability alters differentiation and mechanical cohesion of
tissue-engineered constructs based on human endothelial / stem cells
To move towards clinical applications, tissue engineering (TE) should be
validated with human primary cells and offer easy connection to the
native vascularisation. Based on a sheet-like bone substitute developed
previously, we investigated a mesenchymal stem cells / endothelial cells
(MSCs/ECs) coculture to enhance pre-vascularisation. Using MSCs from 6
independent donors, we focused on donor variability and cell crosstalk.
Coculture was performed on calcium phosphate granules in a specific
chamber (one month). MSCs were seeded first then ECs were added after
two weeks, with control monocultures. Cell viability and organisation
(fluorescence, electronic microscopy), differentiation (ALP
staining/activity, RT-qPCR) and mechanical cohesion were analysed.
Adaptation of the protocol to coculture was validated (high cell
viability and proliferation). Activity and differentiation showed strong
trends towards synergistic effects between cell types. MSCs reached
early mineralization stage of maturation. The delayed ECs addition ECs
allowed for their attachment on developed MSCs. The main impact of donor
variability could be the lack of cell proliferation potential with some
donors, leading to low differentiation and mechanical cohesion and
therefore absence of sheet-like shape successfully obtained with others.
We suggest adapting protocols to cell proliferation potentials from one
batch of cells to the other in a patient-specific approach.