Patterned and switchable surfaces for biomaterial applications

Chapter 1 - Introductionsubstrate. A copolymer ratio for OEGMA/MA of 0.8 was found to be optimalcomposition for both ensuring strong polymer adsorption and cell resistance.Spatially controlled cell attachment with micron resolution was demonstrated usinghuman microvascular endothelial cells.1.2.3. MicrofluidicsMicrofluidics is a different approach to surface patterning whereupon biomoleculemanipulation and spatial control is achieved by limiting the surface of the substratethat is accessible to the solvent carrying the biomolecule of interest. Microfluidicsystems can be complicated, however, for a simple patterning experiment a patternedPDMS stamp, formed in a similar fashion to typical CP experiments, has beenshown to be very useful. The PDMS stamp is typically topographically patternedwith grooves that form sealed channels when the stamp is pressed onto a hard, flatsubstrate surface.Microfluidics often represents a cheaper and simpler solution than otherpatterning techniques and has the unique advantage of being able to separate andcontain the reaction solution, enabling different solutions to be exposed to differentlocations on a particular surface. A further advantage is the gentler processingconditions in comparison to lithographical methods. This enables patterning overpre-attached cells or over proteins, which would be destroyed by harsher treatmentconditions. However, there are limited number of channel geometries available andthe resolution limit is generally lower than for lithographical approaches.A multi-phenotype cell array was formed by encapsulating living cells within ahydrogel matrix, formed inside of a microfluidic channel made of PDMS [52].Various cell lines in a hydrogel precursor solution were injected into parallel1-24