Isolation and in vitro chondrogenic potential of human fetal spine cells

Cell therapy for nucleus pulposus regeneration is an attractive treatment for early disc degeneration as shown by studies using autologous nucleus pulposus cells or stem cells. Another potential source of cells is fetal cells. We investigated the feasibility of isolating fetal cells from human fetal spine tissues and assessed their chondrogenic potential in alginate bead cultures. Histology and immunohistochemistry of fetal tissues showed that the structure and the matrix composition (aggrecan, type I and II collagen) of fetal intervertebral disc were similar to adult intervertebral disc. Isolated fetal cells were cultured in monolayer in basic media supplemented with 10% FBS and from each fetal tissue donation, a cell bank of fetal spine cells at passage 2 was established and was composed of around 2,000 vials of 5 million cells. Gene expression and immunohistochemistry of fetal spine cells cultured in alginate beads during 28 days showed that cells were able to produce aggrecan and type II collagen and very low level of type I and type X collagen, indicating chondrogenic differentiation. However variability in matrix synthesis was observed between donors. In conclusion, fetal cells could be isolated from human fetal spine tissues and since these cells showed chondrogenic potential, they could be a potential cell source for intervertebral disc regeneration.