Connective-Tissue Fibroblasts Established on Micropillar Interfaces are Pivotal for Epithelial-Tissue Morphogenesis

Polydimethylsiloxane (PDMS) pillar arrays are applied as a biomechanical microenvironment to establish gingival connective-tissue fibroblasts (GCTFs) and to further analyze the pivotal role of GCTFs in epithelial-tissue morphogenesis. GCTFs are known to exert successful adhesion and growth on fibronectin immobilized on pillar heads, over time, concomitant with the increased gene expression of vimentin and collagen type-L GCTF-populated pillar arrays clearly reveal that epithelial-tissue morphogenesis of immortalized human gingival keratinocytes (IHGKs), co-cultured for 7 and 14 days, parallels the in vivo phenotype more closely, when compared with GCTF-free control arrays. This in vivo-like phenotype is substantiated by higher mRNA levels for keratin 1, involucrin and filaggrin differentiation markers. Furthermore, it is reflected by a tissue-specific protein orientation of the aforementioned molecules, and also of the cell-to-cell contact forming desmoplakin and the basement membrane constituents, laminin-5, laminin-1/10, and collagen type-IV. These experiments suggest that the in vivo-like phenotype of the IHGK is governed by the GCTFs growing on the micropillar interfaces. Moreover, they form the basis for the optimization or neogeneration of biomaterials by varying predefined microenvironmetal parameters to achieve an in vivo-like cell growth and differentiation, indispensable for tissue morphogenesis during regeneration.