Patterned and switchable surfaces for biomaterial applications

Andrew Hook – Patterned and switchable surfaces for biomaterial applicationsThe known adsorption of DNA to negatively charged surfaces by formation ofcationic bridges with solvated cations [43] suggests that the adsorption of DNA toALAPP by electrostatic contacts could still proceed even in the presence of somenegative surface charge due to anionic functionality. Nevertheless, it is expected thatin solutions of pH less than 5.5 DNA adsorption to ALAPP films should beenhanced. Interestingly, when identical -potential measurements were conducted onALAPP films that were left in air for 2 months, a negative surface charge (-10 mV)resulted, which remained unchanged over the pH range measured, suggesting thatthese films undergo considerable aging over this time period and that the relativeamine content of the film is greatly reduced. For this reason, all subsequent DNAadsorption studies were conducted on fresh ALAPP films after short storage times(