at each of the image recording device 5). Hence, the analysis the effects of surface micro-heterogeneity on protein adsorption is limited by

It has been shown by others that albumins denature to a greater extent on more hydrophobic surfaces [6, 42] and that initial binding rate increases with the ability of HSA to denature upon adsorption [43]. We postulate that strong hydrophobic interactions between a more densely-packed OTS region cause HSA molecules to denature upon adsorption in such a way that multiple surface binding sites are occupied. Because of the rapid depletion of these sites, one would expect to see albumin adsorption reach its steady state more quickly but at a lower adsorption level. We also postulate that areas containing mixed hydrophobic and hydrophilic sites bind protein at greater surface densities but more slowly due to the time required to find the best match between HSA alkyl binding sites and underlying substrate OTS chains. At very low OTS coverage, the OTS molecules are so distantly spaced that the number of OTS-HSA interactions is reduced so that adsorbed amount decreases with decreasing OTS coverage, i.e., with decreasing surface hydrophobicity.