Patterned and switchable surfaces for biomaterial applications

Andrew Hook – Patterned and switchable surfaces for biomaterial applicationsadded. However, this approach currently suffers from difficulties aligning theALAPP/PEG pattern with the DNA array deposited using the non-contact printer.2.4. ConclusionThe formation and characterisation of two-dimensional chemical patterns on p ++silicon substrates using plasma polymerisation of allylamine in conjunction withPEG surface grafting and subsequent patterning by mask-assisted excimer laserablation was demonstrated. The preferential adsorption of DNA onto the ALAPPregions on an ALAPP-PEG patterned surface was noted, showing that the PEG filmrepels not only proteins and cells, as shown before, but also nucleic acids and,therefore, provides a general non-biofouling coating. Furthermore, voltage biasstimulatedadsorption and desorption of DNA on ALAPP coated surfaces wasdemonstrated by fluorescence measurements. Solid phase transfection on ALAPPwas shown to be enhanced by electro-stimulated desorption of DNA. The increase intransfection efficiency from 13% to 30% compares favourably with literature valuesand is an important step in improving solid phase transfection. The formation of aTCM on a chemically patterned substrate was also shown to be possible.2-95