Treatment of ocular surface injuries by limbal and mesenchymal stem cells growing on nanofiber scaffolds.

Stem cell (SC) therapy represents a promising approach to treat a wide variety of injuries, inherited diseases, or acquired SC deficiencies. One of the major problems associated with SC therapy remains the absence of a suitable matrix for SC growth and transfer. We describe here the growth and metabolic characteristics of mouse limbal stem cells (LSCs) and mesenchymal stem cells (MSCs) growing on 3D nanofiber scaffolds fabricated from polyamide 6/12 (PA6/12). The nanofibers were prepared by the original needleless electrospun Nanospider technology, which enables to create nanofibers of defined diameter, porosity, and a basis weight. Copolymer PA6/12 was selected on the basis of the stability of its nanofibers in aqueous solutions, its biocompatibility, and its superior properties as a matrix for the growth of LSCs, MSCs, and corneal epithelial and endothelial cell lines. The morphology, growth properties, and viability of cells grown on PA6/12 nanofibers were comparable with those grown on plastic. LSCs labeled with the fluorescent dye PKH26 and grown on PA6/12 nanofibers were transferred onto the damaged ocular surface, where their seeding and survival were monitored. Cotransfer of LSCs with MSCs, which have immunosuppressive properties, significantly inhibited local inflammatory reactions and supported the healing process. The results thus show that nanofibers prepared from copolymer PA6/12 represent a convenient scaffold for growth of LSCs and MSCs and transfer to treat SC deficiencies and various ocular surface injuries.