Bioactive Nanofiber Matrices Functionalized with Fibronectin-Mimetic Peptides Driving the Alignment and Tubular Commitment of Adult Renal Stem Cells

Bioactive, electrospun polymer nanofibers (NFs) are attractive building-block materials for realizing scaffolds for tissue engineering, as these filaments structurally mimic the hierarchical organization of natural extracellular matrix. As presented in this article, demonstrated applications involve the commitment to adipogenic, chondrogenic, osteogenic, neural lineages, and so on, by different types of stem cells obtained from various sources (adult, embryonic, induced pluripotent stem cells, etc.). Since a poor cellular colonization may limit the usefulness of scaffolds for culturing delicate stem cell populations, coupling NFs with cell-adhesive domains is highly desirable. In our work, the surface of either isotropic (randomly orienteor anisotropic (highly aligneelectrospun poly(l-lactic acid) fibrous scaffolds with fibronectin (FN)-mimetic peptides is tailored. The effects of the peptide immobilization on the adhesion and spreading of human, adult renal stem cells are investigated. Functionalized, aligned NFs are suitable scaffolds to promote the confluent growth of stem cells and to enhance their differentiation toward the tubular epithelial lineage. It is anticipated that the functionalization of aligned NFs with FN-mimetic peptides might be a promising method to target a specific response of stem cells in renal tissue engineering. The design and realization of electrospun nanofibers coupled with a fibronectin-mimetic peptide is described. The effect of the scaffolds on the behavior of renal stem cells is analyzed. These bioactive fibers might be useful for the definition of new biomimetic platforms to effectively culture and commit renal stem cells, allowing confluent and functional cell layers to be generated which are analogous to the renal proximal tubule epithelium.