Femke Mathot

6 Vascularization in stem cell seeded nerve allografts 99 Data are expressed as the mean ± SD. The level of statistical significance was set at a =0.05. RESULTS Differentiation of MSCs into Schwann-like cells Differentiated MSCs all adjusted morphologically to a spindle-like shape and demonstrated expression of Schwann cell markers S100, GFAP and NTR p75, which is in accordance with Schwann cells ( figure 1 ) and previous studies. Figure 1. Differentiation of MSCs into Schwann-like cells was confirmed by comparing the expression of Schwann cell markers S100 (A-B-C), GFAP (D-E-F) and NTR p75 (G-H-I) in the differentiated MSCs (B-E-H) to the expression in Schwann cells (C-F-I) and undifferentiated MSCs (A-D-G). Vascular surface area Non-operated nerves had a vascular surface area percentage of 34.9 ± 5.7%. Of the four studied groups, the vascular surface area was highest in the group that received allografts seeded with differentiated MSCs (38.9 ± 7.0%), followed by the group with autografts (29.5 ± 8.7%) and the group with allografts seeded with undifferentiated MSC (29.2 ± 3.4%). Unseeded allografts (21.2 ± 6.2%) had a significantly lower mean vascular surface area percentage than normal non- operated nerves (13.7%, p=0.001) and allografts seeded with differentiated MSCs (17.8%, p=0.001) ( figure 2 and 3 ).