A comparative study on culture conditions and routine expansion of amniotic fluid-derived mesenchymal progenitor...

Amniotic fluid (AF) cell populations will be applied in perinatology. We aimed to test the feasibility of large-scale cell expansion.

We determined the best out of three published expansion protocols for mesenchymal progenitors (AF samples, n = 4) in terms of self-renewal ability. Characterization was performed based on morphology, surface marker analysis, cytogenetic stability, and differentiation potential. The conditions for the best self-renewal ability were further determined in a consecutive series (n = 159).

The medium containing fetal bovine serum (FBS), epidermal growth factor, insulin, transferrin, and tri-iodothyronine, combined with seeding on gelatin-coated wells, best stimulated the growth of cells with mesenchymal features, as demonstrated by flow cytometry; however, only osteogenic differentiation was possible. Large-scale testing (n = 44) failed to confirm a robust self-renewal ability. Better results were obtained (n = 88) using optimized FBS or an increased initial cell density. Eventually over 81% of cultures continued growing after the initial medium change and had mesenchymal features but failed differentiation assays.

Routine in vitro expansion of AF-derived mesenchymal cells remains problematic. Despite an increase in successful cell cultures from 40 up to 80% using optimized serum and an increased cell density, eventually cells failed to demonstrate differentiation abilities. Routine isolation and expansion from unselected AF samples remains a challenge.