The Effect of Surface Nanometre-Scale Morphology on Protein Adsorption
Figure 6
AFM quantitative image analysis of surface morphology.
Analysis performed on samples synthetized for AFM experiment (RMS roughness 26.2±0.1 nm): (A) widths spectrum of pores after sample incubation with PBS, fibrinogen at 0.28 µM and 4.4 µM, the distribution is very similar before and after fibrinogen adsorption; (B) depth spectrum of pores after sample incubation with PBS, fibrinogen at 0.28 µM and 4.4 µM, depth distribution after adsorption at 4.4 µM is very different from the other two in the whole depth range; in the region between 40 nm and 100 nm, the population is completely depleted; (C) aspect ratio spectrum of pores after sample incubation with PBS, fibrinogen solution at 0.28 µM and 4.4 µM; for aspect ratios higher than 0.5, 75% of pores are filled, showing that nucleation preferentially occurs in pores with higher aspect ratio. Analysis performed on samples 1 and 5 used in previous FPQ and PSIM experiments: (D) width spectrum of pores for samples 1 and 5 as-deposited shows that increasing surface roughness does not substantially change the width distribution; (E) depth spectrum of pores for samples 1 and 5 as-deposited shows that the increase in surface roughness is related to the increase of the pores depth; (F) aspect ratio spectrum of pores for samples 1 and 5 as-deposited; the higher roughness of sample SMP5 results in an aspect ratio distribution with a significantly higher population for aspect ratio higher than 0.5.