FIBRONECTIN ADSORPTION-KINETICS ON PHASE SEGREGATED POLYURETHANEUREAS

The kinetics of fibronectin (FN) adsorption upon three polyurethaneure as (PUU) were measured by Fourier transform infrared spectroscopy. The three polymers had soft blocks composed of polydimethylsiloxane (PDMS ), polytetramethyleneoxide (PTMO), and polyethyleneoxide (PEO). On eac h polymer, the amount of adsorbate increased proportional to the squar e root of time, but the rates were less than that predicted for purely diffusion controlled adsorption. Adsorption rate constants and sticki ng coefficients (the fraction of encounters with the surface which res ult 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 PDM S-PUU, PTMO-PUU and PEO-PUU respectively. The rate constants and stick ing coefficients fall within the range of previously reported values f or other protein/polymer systems. The sticking coefficients correlate in general with the amount of FN adsorbed at 120 min, and with the ext ent of conformational change of the adsorbed protein.