Non-specific adhesion on biomaterial surfaces driven by small amounts of protein adsorption

作者：Kalasin Surachate; Santore Maria M^*

来源：Colloids and Surfaces B: Biointerfaces , 2009, 73(2): 229-236.

DOI：10.1016/j.colsurfb.2009.05.028

• Bioadhesion
• Bacterial adhesion
• Flow
• Biofouling
• Electrostatic
• Salt effects
• Screening
• Heterogeneity
• Hydration effects
• Charge patchiness

This work explores how long-range non-specific interactions, resulting from small amounts of adsorbed fibrinogen, potentially influence bioadhesion. Such non-specific interactions between protein adsorbed on a biomaterial and approaching cells or bacteria may complement or even dominate ligand-receptor mating. This work considers situations where the biomaterial surface and the approaching model cells (micron-scale silica particles) exhibit strong electrostatic repulsion, as may be the case in diagnostics and lab-on-chip applications. We report that adsorbed fibrinogen levels near 0.5 mg/m(2) produce non-specific fouling. For underlying surfaces that are less fundamentally repulsive, smaller amounts of adsorbed fibrinogen would have a similar effect. Additionally, it was observed that particle adhesion engages sharply and only above a threshold loading of fibrinogen on the collector. Also, in the range of ionic strength. 1, below about 0.05 M, increases in 1 reduce the fibrinogen needed for microparticle capture, due to screening of electrostatic repulsions. Surprisingly, however, ionic strengths of 0.15 M reduce fibrinogen adsorption altogether. This observation opposes expectations based on DLVO arguments, pointing to localized electrostatic attractions and hydration effects to drive silica-fibrinogen adhesion. These behaviors are benchmarked against microparticle binding on silica surfaces carrying small amounts of a polycation, to provide insight into the role of electrostatics in fibrinogen-driven non-specific adhesion.

• 出版日期2009-10-15