Figure 5. Cells isolated from each of three scaffolds were serially propagated for three passages. This allowed us to obtain information about the residual clonogenic potential of the cells grown onto the scaffolds and to evaluate the effects of the matrix on the preservation of stemness and induction of differentiation pathways. [HKL + 3T3/J2] = HKLs with 3T3-J2 feeder layer; [HKL - 3T3/J2] = HKLs without 3T3-J2 feeder layer. No difference in the number of clonogenic cells (A) or percentage of aborted colonies (aborted colonies/total colonies ratio; B) was observed when cells isolated from HKLs (in the presence of 3T3-J2 feeder layers) or fibrin were compared. In the absence of a 3T3-J2 feeder layer, reduced number of clonogenic cells and increased percentages of aborted colonies were observed. Despite this, cells were found proliferating for at least three passages in culture, thus suggesting that HKLs might not interfere with the stemness and proliferative potential of corneal stem cells. Error bars indicate SEM (n=3).