Patterned and switchable surfaces for biomaterial applications

Andrew Hook – Patterned and switchable surfaces for biomaterial applicationsFinally, the Whitesides group has extensively investigated methods of cellpatterning including CP, microfluidics and laminar flow patterning. Much of thisresearch has been previously reviewed [4, 85, 89-91].1.2.4. MicroelectronicsMicroelectronics is a new field that exploits microcircuitry to manipulatebiomolecules and cells. This technique has been developed by Huang et al., [77] toseparate monocytic white blood cells and human T cells transformed with theoncogene Tax from human peripheral blood mononuclear cells as well asneuroblastoma cells from glioma cells on the basis of the distinct dielectric propertiesof the different cell types. Using a microelectronic chip array, effective separationand sorting of different cell types was demonstrated (Figure 1.5) by stepwise additionof cells (Figure 1.5A), separation by dielectrophoresis (Figure 1.5B), and thenwashing by buffer (Figure 1.5C and D). Microelectronic chips have also been shownto effectively control DNA adsorption and surface diffusion [92, 93]. This method islimited by the electrode pattern that can be fabricated. However, this approach doescombine spatial control with switchability. Furthermore, as well as having the abilityto pattern cells, it has the unique capability to control surface diffusion of cells,which adds a new dimension to advanced cellular manipulation.1-27