Comparison between different biomaterial scaffolds for limbal-derived stem cells growth and enrichment

Corneal epithelial stem cells have been used for the treatment of total limbal deficiency with corneal conjunctivalization and decreased vision secondary to a variety of ocular surface diseases. We set to compare the ability of different extracellular components in promoting growth and migration of these cells.

Growth parameters were evaluated, including cell migration and proliferation (by wound healing) and mRNA gene expression (by quantitative RT-PCR).

The growth of corneal epithelial cells plated onto different matrix has shown that all treatments were efficient in supporting exponential growth, with a small increase in the puramatrix and collagen I groups when compared with fibrin treatment, which displayed the best doubling time rate and saturation density. The mRNA relative levels for c-myc, a proliferation marker, were considerably higher in the fibrin-coated group. In a smaller extent, the same could be observed for the puramatrix and collagen I groups. The same pattern could be observed for β-1 and α-6-integrin mRNA relative levels. The levels of CD71 mRNA, a LESC negative marker, were decreased in all groups, with a greater decrease in the fibrin group. We also found that the relative mRNA levels of the efflux pump ABCG2 and ΔNp63 transcripts were significantly higher in the fibrin group but not for collagen and puramatrix groups. Moreover, a diminished capacity of wound repair was observed for the uncoated control while the coated biomaterial groups were able to restore the cell-covered surface at some extent.

All components tested were effective in promoting growth of corneal epithelial cells and maintenance of stem cell putative markers when compared with the uncoated surface group. Fibrin was far superior than collagen I and puramatrix in promoting survival, growth and migration of these cells.