Patterned and switchable surfaces for biomaterial applications

CHAPTER 1.INTRODUCTION1The content of this chapter is based upon references [1, 2].1.Advanced biodevices that are able to control the behaviour of biomolecules atsurfaces in both space and time are promising tools for elucidating solutions to manybiologically based problems and are of particular interest to combat physiologicaldisorders. Biomolecules of interest include proteins and shorter peptide chains,deoxyribonucleic acid (DNA), ribonucleic acid (RNA), oligonucleotides(oligonucleotides are short (2-50) bp of typically single stranded DNA), lipids andpolysaccharides, as well as larger assemblies of these biomolecules, in particularliving cells. Examples of such devices can be found in microarray technology, in‘smart’ drug delivery, biosensing, bioelectronics and tissue engineering [3-8]. Thedevelopment of a number of high-resolution two dimensional (2D) and threedimensional (3D) patterning techniques coupled with functional surface chemistryhas enabled the formation of surfaces that offer stringent control over the adsorptionof biomolecules and cells in space. Furthermore, the development of switchablesurfaces that are able to respond to a particular signal to switch between disparateproperties, such as hydrophobic/hydrophilic, positive/negative or swollen/collapsed,has added a new dimension to biomolecule manipulation. Individually, theseprocesses have enabled the production of a number of advanced biodevices.Recently, these processes have been combined, producing devices that are able tocontrol biomolecules and cells in both space and time, offering an unprecedentedability to manipulate biomolecular behaviour.In order to manipulate biomolecules at surfaces, a thorough understanding of theirbehaviour at solid-liquid interfaces is required. Biomolecules differ substantially1-2