Influence of Different ECM Mimetic Peptide Sequences Embedded in a Nonfouling Environment on the Specific Adhesion of Human-Skin Keratinocytes and Fibroblasts on Deformable Substrates

Mechanical stress is a decisive factor for the differentiation, proliferation, and general behavior of cells. However, the specific signaling of mechanotransduction is not fully understood. One basic problem is the clear distinction between the different extracellular matrix (ECM) constituents that participate in cellular adhesion and their corresponding signaling pathways. Here, a system is proposed that enables mechanical stimulation of human‐skin‐derived keratinocytes and human dermal fibroblasts that specifically interact with peptide sequences immobilized on a non‐interacting but deformable substrate. The peptide sequences mimic fibronectin, laminin, and collagen type IV, three major components of the ECM. To achieve this, PDMS is activated using ammonia plasma and coated with star‐shaped isocyanate‐terminated poly(ethylene glycol)‐based prepolymers, which results in a functional coating that prevents unspecific cell adhesion. Specific cell adhesion is achieved by functionalization of the layers with the peptide sequences in different combinations. Moreover, a method that enables the decoration of deformable substrates with cell‐adhesion peptides in extremely defined nanostructures is presented. The distance and clustering of cell adhesion molecules below 100 nm has been demonstrated to be of utmost importance for cell adhesion. Thus we present a new toolbox that allows for the detailed analysis of the adhesion of human‐skin‐derived cells on structurally and biochemically decorated deformable substrates. Skintight evidence: Deformable substrates (PDMS and PEG‐based hydrogels) were surface‐engineered to yield a nonadhesive interface in which different extracellular matrix protein‐mimetic peptides derived from laminin, fibronectin, and collagen type IV were embedded to allow specific adhesion of human‐skin keratinocytes (like that shown in the picture) and dermal fibroblasts.