Patterning biomolecules on polymer surfaces for applications in life sciences

The development of in-mould patterning, a novel technique for patterning proteins on polymer surfaces, is described. Patterns of proteins were transferred to polymer surfaces during polymer shaping by use of a simple and easily scalable process. In-mould patterning combines the industrial process of injection moulding with the patterning technique of micro contact printing. Through micro contact printing, proteins were transferred onto raised areas of a mould. The injection moulding process subsequently immobilized the proteins in defined regions at the polymer replica surface. Patterns with feature sizes spanning from nano- to centimetres were produced. Immobilization of proteins by use of this method was demonstrated for horseradish peroxidase, fibronectin, avidin and IgG. The structure of the transferred proteins was sufficiently preserved to retain their enzymatic activity, cell adhesion promoting properties, or ability to bind specific ligands, respectively. As part of the development of the in-mould patterning technique, fundamental studies on micro contact printing using hydrophobic stamps were carried out.

To demonstrate the versatility of the technique, studies on Pdcolloid patterning were undertaken. Construction of interdigitated arrays of microscopic copper wires, located in recessed areas on polymer replicas through in-mould patterning was demonstrated. Pd-colloids were in-mould patterned onto recessed areas of a replica and subsequently served as catalysts for the electroless deposition of copper in the recessed areas.