Tuning InAs Nanowire Density for HEK293 Cell Viability, Adhesion, and Morphology: Perspectives for Nanowire-Based Biosensors

Arrays of nanowires (NWs) are currently being established as vehicles for molecule delivery and electrical- and fluorescence-based platforms in the development of biosensors. It is conceivable that NW-based biosensors can be optimized through increased understanding of how the nanotopography influences the interfaced biological material. Using state-of-the-art homogenous NW arrays allow for a systematic investigation of how the broad range of NW densities used by the community influences cells. Here it is demonstrated that indium arsenide NW arrays provide a cell-promoting surface, which affects both cell division and focal adhesion up-regulation. Furthermore, a systematic variation in NW spacing affects both the detailed cell morphology and adhesion properties, where the latter can be predicted based on changes in free-energy states using the proposed theoretical model. As the NW density influences cellular parameters, such as cell size and adhesion tightness, it will be important to take NW density into consideration in the continued development of NW-based platforms for cellular applications, such as molecule delivery and electrical measurements

Tuning InAs Nanowire Density for HEK293 Cell Viability, Adhesion, and Morphology: Perspectives for Nanowire-Based Biosensors

Arrays of nanowires (NWs) are currently being established as vehicles for molecule delivery and electrical- and fluorescence-based platforms in the development of biosensors. It is conceivable that NW-based biosensors can be optimized through increased understanding of how the nanotopography influences the interfaced biological material. Using state-of-the-art homogenous NW arrays allow for a systematic investigation of how the broad range of NW densities used by the community influences cells. Here it is demonstrated that indium arsenide NW arrays provide a cell-promoting surface, which affects both cell division and focal adhesion up-regulation. Furthermore, a systematic variation in NW spacing affects both the detailed cell morphology and adhesion properties, where the latter can be predicted based on changes in free-energy states using the proposed theoretical model. As the NW density influences cellular parameters, such as cell size and adhesion tightness, it will be important to take NW density into consideration in the continued development of NW-based platforms for cellular applications, such as molecule delivery and electrical measurements

Biomimetic Cryptic Site Surfaces for Reversible Chemo- and Cyto-Mechanoresponsive Substrates

Chemo-mechanotransduction, the way by which mechanical forces are transformed into chemical signals, plays a fundamental role in many biological processes. The first step of mechanotransduction often relies on exposure, under stretching, of cryptic sites buried in adhesion proteins. Likewise, here we report the first example of synthetic surfaces allowing for specific and fully reversible adhesion of proteins or cells promoted by mechanical action. Silicone sheets are first plasma treated and then functionalized by grafting sequentially under stretching poly(ethylene glycol) (PEG) chains and biotin or arginine-glycine-aspartic acid (RGD) peptides. At unstretched position, these ligands are not accessible for their receptors. Under a mechanical deformation, the surface becomes specifically interactive to streptavidin, biotin antibodies, or adherent for cells, the interactions both for proteins and cells being fully reversible by stretching/unstretching, revealing a reversible exposure process of the ligands. By varying the degree of stretching, the amount of interacting proteins can be varied continuously