Fibronectin adsorpton kinetics on phase segregated polyurethaneureas

Abstract

The kinetics of fibronectin (FN) adsorption upon three polyurethaneureas (PUU) were measured by Fourier transform infrared spectroscopy. The three polymers had soft blocks composed of polydimethylsiloxane (PDMS), polytetramethyleneoxide (PTMO), and polyethyleneoxide (PEO). On each polymer, the amount of adsorbate increased proportional to the square root of time, but the rates were less than that predicted for purely diffusion controlled adsorption. Adsorption rate constants and sticking coefficients (the fraction of encounters with the surface which result in adsorption) were calculated from the data. The adsorption rate constants are 4.8 x 10(-4), 1.3 x 10(-4), and 2.5 x 10(-5) cm/s on PDMS-PUU, PTMO-PUU and PEO-PUU respectively. The rate constants and sticking coefficients fall within the range of previously reported values for other protein/polymer systems. The sticking coefficients correlate in general with the amount of FN adsorbed at 120 min, and with the extent of conformational change of the adsorbed protein.