Patterned and switchable surfaces for biomaterial applications

Andrew Hook – Patterned and switchable surfaces for biomaterial applicationsto produce low-fouling surfaces [69]. By saturating a surface with these ‘sticky’proteins, the subsequent adsorption of other proteins can be prevented.1.2. Surface micro- and nano-patterningThe formation of micro- and nano-patterns of biomolecules on surfaces has beenwidely explored and enables the production of sophisticated biomaterials [6, 70, 71],the exploration of biomimetics [72], and the formation of advanced microarrays [41,73]. Spatial control of biomolecules on solid substrate materials can be achievedusing a variety of approaches to patterning. Specific strategies for the surfacepatterning of biomolecules include microfluidics, microcontact printing (CP),microelectronics, photolithography, soft-lithography, laser ablation and roboticspotting [33, 74-79]. A detailed technical review of patterning techniques hasrecently been published [66]. Furthermore, effective spatial control of cell-surfaceinteractions is also possible indirectly via spatially controlling biomoleculeattachment to surfaces. Some of the methods that have been used with success arelisted below, and a table of their advantages, disadvantages and applications is shownin Table 1.2 (see section 1.4.4.2).1.2.1. PhotolithographyPhotolithography involves the irradiation of a surface by a high-energy beam,typically ultraviolet (UV) light, through a photomask. Surface alterations can includethe ablation of a photoresist layer, breaking of a chemical bond resulting in therelease of an attached molecule, initiation of polymerisation or initiation of formationof a chemical bond resulting in the grafting of a molecule [53, 78, 80].Photolithography is also utilised for patterning of surfaces to create topographical1-17