Authors: S. Genov, I. Thurow, D. Riester, K. Borchers, T. Hirth, A. Weber, G.E.M. Tovar
Affilation: University of Stuttgart & Fraunhofer Gesellschaft, Germany
Pages: 643 - 646
Keywords: stabilisation of native protein, polymer film, LIFT process
To produce nano-scale native protein trehalose patterns on 3D and 2D substrates in constant concentration by Laser-Induced-Forward Transfer (LIFT), ultrathin coatings on LIFT targets are needed . The LIFT process is used as a non-contact method to transfer protein patterns on substrates at a distance of 100 µm to 300 µm. Biochips generated as biosensors can be spotted with variable protein combinations in different concentrations. In this way protein based biosensor assays can be achieved by selected cell adsorption. Thin trehalose layers with embedded proteins like green fluorescent protein (GFP), streptavidine and the extra cellular matrix (ECM) protein laminin type1 were generated by a spin-coating technique on titanium coated targets. Robustness against long term storage is a key feature for applications, which needs multi-protein spotting (sensors; 3D cell cultures). To examine the protein stability the protein coatings were exposed to long term experiments [2, 4]. Coating thickness was examined by means of ellipsometric spectroscopy on a statistically relevant number of samples. During the LIFT process, the proteins are exposed to both mechanical stress and heat stress. Thus, subsequent tests are mandatory to grant the activity of the proteins after the transfer process. Our main focus is to examine the quality of the micro structured coatings transfered by the LIFT process using analysis by REM, AFM, XPS and protein activity tests . Activity tests are either done by application of a fluorescence scan (GFP and streptavidin with fluorescence-labelled biotin) or cell adhesion tests on transferred laminin type1 with fibroblasts.