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

Abstract

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.

Surface Modification of Polydimethylsiloxane Substrates with Nonfouling Poly(Poly(ethylene glycol)methacrylate) Brushes

“…Often these coatings are based on poly(ethylene glycol) (PEG) or PEGlike materials. One strategy that is frequently used involves the grafting of appropriate end-group reactive PEG derivatives on UV or plasma-activated PDMS surfaces either via covalent [3][4][5] or noncovalent bonds. [6] Alternatively, hydrophilic, nonfouling coatings can be prepared by polymerization of appropriate monomers from initiator sites located at the PDMS surface.…”

Biocompatibility of PLGA/sP(EO-stat-PO)-Coated Mesh Surfaces under Constant Shearing Stress

“…Due to the soft consistency of liver parenchyma in some cases, liver tissue protruded through the gaps between the mesh filaments. Previous in vitro studies on cell cultures using the same type of chemical substances described here suggested cell-repellent and anti-adhesive qualities [10,20,21]. This certainly was not demonstrable within this in vivo animal model.…”

“…For the diaphragmatic location, an airtight cover is warranted. This was achieved by a new surface modification [10,11]. The main aim of this modification is the creation of a chemical basis for further attachment of bioactive substances, which will positively affect scar formation and tissue regeneration in the future.…”

“…Ultrapro and polypropylene meshes were activated using NH 3 plasma (360 W, 120 s, 0.4 mbar) to generate amino groups on the fiber surfaces [10]. These are used for covalent attachment of NCO-sP(EO - stat - PO), a coating system that is based on 6-armed star-shaped polymers on PEO (polyethylene oxide) basis with reactive isocyanate (NCO) groups at the distal endings (fig.…”

Silicones for Microfluidic Systems

“…Surface etching with plasma (oxygen [33,36,37], air [38], NH 3 [39] , argon [33], helium [33] or nitrogen [23]) consisting of high energy species such as electrons, ions and radicals, induces degradation of the polymer structure (siloxane bonds redistribution, removal of methyl groups from the polymer chain - Figure 24.2) and leads to formation of a thin, solid and hydrophilic surface layer (containing SiO x moieties and silanol groups [40,41]). Th e formation of functional groups as a result of plasma treatment is restricted to a depth of few hundred nanometers into the polymer bulk.…”