Effect of hydroxy-PEO chain density and uremic toxins on plasma protein adsorption

Abstract

Protein adsorption influences the host response to blood contacting biomaterials. End-tethered polyethylene oxide (PEO) is a gold-standard film for reducing non-specific protein adsorption at the blood-material interface. That said, almost all protein adsorption studies utilize blood from healthy donors, whereas blood composition can vary greatly depending on the disease. Kidney failure leads to the dramatic retention of small molecules (i.e., uremic toxins) within the blood compartment, and their effect on the inhibition of protein adsorption to PEO films is unknown. To understand the effect these uremic toxins have on protein adsorption, surfaces with different chain densities of end-tethered hydroxy-PEO were incubated in platelet-poor plasma laden with uremic toxins. PEO films were characterized using dynamic contact angles and X-ray photoelectron spectroscopy. PEO chain densities were verified using spectroscopic ellipsometry. Eluted proteins were characterized using immunoblot techniques. It was observed that PEO chain density and uremic toxins affected the amount of individually adsorbed proteins and the relative composition of the adsorbed protein corona; especially albumin, complement C3, factor XI, and fibrinogen. This knowledge is considered crucial to the advancement of surfaces for a personalized approach to treating patients with kidney failure.