Publication Date

6-30-2019

Department

Ames Laboratory

Campus Units

Ames Laboratory

OSTI ID+

1560661

Report Number

IS-J 10009

DOI

10.1021/acs.langmuir.9b00702

Journal Title

Langmuir

Volume Number

35

Issue Number

30

First Page

9769

Last Page

9776

Abstract

Poly(ethylene glycol) (PEG) is widely used to modulate the hydration states of biomaterials and is often applied to produce nonfouling surfaces. Here, we present X-ray scattering data, which show that it is the surface segregation of PEG, not just its presence in the bulk, that makes this happen by influencing the hydrophilicity of PEG-containing substrates. We demonstrate a temperature-dependent trigger that transforms a PEG-containing substrate from a protein-adsorbing to a protein-repelling state. On films of poly(desaminotyrosyl-tyrosine-co-PEG carbonate) with high (20 wt %) PEG content, in which very little protein adsorption is expected, quartz crystal microbalance data showed significant adsorption of fibrinogen and bovine serum albumin at 8 °C. The surface became protein-repellent at 37.5 °C. When the same polymer was iodinated, the polymer was protein-adsorbent, even when 37 wt % PEG was incorporated into the polymer backbone. This demonstrates that high PEG content by itself is not sufficient to repel proteins. By inhibiting phase separation either with iodine or by lowering the temperature, we show that PEG must phase-separate and bloom to the surface to create an antifouling surface. These results suggest an opportunity to design materials with high PEG content that can be switched from a protein-attractant to a protein-repellent state by inducing phase separation through brief exposure to temperatures above their glass transition temperature.

DOE Contract Number(s)

AC02-07CH11358; EB001046

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Tuesday, June 30, 2020

Share

COinS