Patterned and switchable surfaces for biomaterial applications

Andrew Hook – Patterned and switchable surfaces for biomaterial applicationstechniques have been developed to achieve these various abilities, however, the mostinteresting and useful systems are those that combine patterns on the micro- or evennano-scale and switchable architectures to achieve both temporal and spatial controlover biomolecule surface interactions.Recent studies have shed some light on understanding the processes involved withthe adsorption and desorption of DNA at the solid/liquid interface. As a stablepolyelectrolyte with in-built molecular recognition properties, DNA is an interestingand unique biomolecule, and owing to its biological importance it is an ideal focusfor the development of biodevices. The manipulation of DNA on a surface requirescontrol over electrostatic and hydrophobic interactions, the driving force for DNAadsorption. Typically, low pH and high salt concentrations enhance DNA adsorption.These principles have been utilised recently to improve DNA based biodevices forexample TCMs.The manipulation of cells at surfaces has been an area of significant recentresearch interest. Chemical, biological and topographical cues have been all shown tobe effective in controlling cell surface interactions. Generally, the control of cellattachment is achieved via the manipulation of the proteins that the cells themselvesproduce to mediate their attachment to surfaces. Protein adsorption, driven largely byhydrophobic forces, has also attracted much interest, and the ability to patternsurfaces with proteins enables cell patterning. Key discoveries have led to patternedcultures of cells with micron resolution using a wide variety of cell types andsubstrate materials. The development of switchable systems for cell attachment hasenabled formation of patterned co-cultures of cells and opens up exciting possibilitiesfor applications in tissue engineering and stem cell research.1-59