Force spectroscopy study of the adhesion of plasma proteins to the surface of a dialysis membrane: role of the nanoscale surface hydrophobicity and topography.
A mechanochemical study of the process of adhesion of plasma proteins to the surface of dialysis membranes was carried out with a scanning force microscope (SFM) in the force spectroscopy mode. Three representative blood plasma proteins (fibronectin, fibrinogen, and albumin) covalently were grafted to a SFM probe, and the adhesion forces of these proteins to cellulosic and synthetic dialysis membranes were measured. The experiment was tailored to apply a controlled load on the protein molecules adsorbed onto the surface in order to simulate the squeezing forces exerted on them during blood filtration. The de-adhesion forces, measured using this new approach for studying the interaction between a protein and dialysis membranes, suggest that the membrane's topography, at a nanometer scale, plays a critical role in the adhesion process. This result was strongly supported by parallel experiments performed on a flattened glass surface with the same dominant hydrophilic character as dialysis membranes. In contrast, a hydrophobic polystyrene surface led to de-adhesion forces at least one order of magnitude greater, overwhelming any possible shape recognition process between the protein molecules and the surface.
Conti
Matteo
M
Dipartimento di Biochimica, Università di Bologna, Via Irnerio 48, Italy.
Donati
Gabriele
G
Cianciolo
Giuseppe
G
Stefoni
Sergio
S
Samorì
Bruno
B
D001798:Blood Proteins / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008567:Membranes, Artificial; D018625:Microscopy, Atomic Force; D011485:Protein Binding; D006435:Renal Dialysis / Q000295:instrumentation*; D012709:Serum Albumin / Q000378:metabolism; D013499:Surface Properties
D001798:Blood Proteins; D005353:Fibronectins; D008567:Membranes, Artificial; D012709:Serum Albumin; D005340:Fibrinogen