Two surface gradients of polyethylene glycol for a reduction in protein adsorption

Abstract

Polyethylene glycol (PEG) coatings have been commonly used in reducing protein adsorption with the intent of improving a biomaterial’s biocompatibility. To elucidate the role of PEG surface density in reducing protein adsorption, two types of grafted PEG surface density gradients were evaluated for the adsorption and desorption of albumin and fibrinogen, two blood proteins. PEG density gradients were characterized using contact angle measurements and X-ray photoelectron spectroscopy. Total internal reflection fluorescence was used to measure protein adsorption kinetics and adsorption profiles on the two types of PEG gradients. The PEG gradient generated by the flow method decreased adsorption of both proteins in proportion to the PEG surface density; however, their desorption by buffer solution from the grafted PEG layer was not complete. In contrast, desorption of two proteins from the grafted PEG layer generated by a UV oxidation method resulted in near-zero adsorbed amount. The difference between the two types of gradients might have originated from counter-diffusion of PEG and water molecules occurring during the flow method procedure.

DMSA-Functionalized Mesoporous Alumina with a High Capacity for Selective Isolation of Immunoglobulin G

“…The high-resolution S 2p spectrum of DMSA–MA (Figure b) exhibits two peaks: a strong peak at 163.61 eV, representative of a C–S bond, and a weak peak at 168.61 eV. This could be possibly due to excessive oxidation of thiols during the reaction, indicating the sulfur atoms are oxidized to the sulfonate moiety. The fraction of sulfur in the oxidized state was around 0.27.…”

Enhancing the specificity of polymerase chain reaction by graphene oxide through surface modification: zwitterionic polymer is superior to other polymers with different charges

“…Abbreviations: GO, graphene oxide; PAA, polyacrylic acid; PAM, polyacrylamide; PCR, polymerase chain reaction; PEG, polyethylene glycol; pSB, poly(sulfobetaine). protein adsorption, 49 and zwitterionic polymer has better ability to reduce protein adsorption than PEG. 50 Binding affinities of polymers with Pfu polymerase (Table S8) also support the result.…”

Editorial

“…4 Two different PEG gradients were prepared through the flow method and gradient UV oxidation, which led reactive surface sulfhydryl groups to convert into sulfonate moieties (A and B, respectively). Adsorption and desorption of both fluorescentlylabelled human serum albumin and fibrinogen proteins on prepared gradient PEG surfaces were studied and quantified using the total internal reflection fluorescence spectroscopy with sub-millimeter resolution.…”