Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/58199

Title

Ultrasensitive probing of the protein resistance of PEG surfaces by secondary ion mass spectrometry

Author(s)

Kingshott, Peter;  McArthur, Sally L.;  Thissen, Helmut;  Castner, David G.;  Griesser, Hans J.

Abstract

The highly sensitive surface analytical techniques X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectrometry (ToF-SIMS) were used to test the resistance of poly(ethylene glycol) (PEG) coatings towards adsorption of lysozyme (LYS) and fibronectin (FN). PEG coatings were prepared by grafting methoxy-terminated aldehyde-PEG (MW 5000Da) onto two amino-functionalised surfaces with different amine group densities, generated by radio frequency glow discharge polymerisation of n-heptylamine and allylamine. Grafting was performed at the lower critical solution temperature to maximise the graft density of the PEG chains. XPS showed that the grafted density of PEG chains was slightly higher on the allylamine surface. XPS detected no adsorption of either protein on either PEG coating. ToF-SIMS analysis, on the other hand, found, in the positive ion spectra, minute but statistically significant signals assignable to amino acid fragment ions from both proteins adsorbed to the lower density PEG coating and from LYS but not FN on the higher density PEG coating. Negative ion spectra contained relatively more intense protein fragment ion signals for the lower density PEG coating but no changes assignable to adsorbed proteins on the higher density PEG coating. These results demonstrate the importance of utilising highly sensitive techniques to study protein adsorption on surfaces intended to be protein resistant, and that both positive and negative ion ToF-SIMS spectra should be acquired to probe for possible very low levels of protein adsorption.

Publication type

Journal article

Source

Biomaterials, Vol. 23, no. 24 (Dec 2002), pp. 4775-4785

Publication year

2002

Keyword(s)

Adsorption;  Aldehydes;  Amino acids;  Biocompatible materials;  Density;  Electron probe microanalysis;  Fibronectins;  Grafts;  Lysozyme;  Macrogol;  Mass spectrometry;  Material coating;  Muramidase;  PEG;  Polyethylene glycols;  Polymerisation;  Protein adsorption;  Proteins;  Radiofrequency;  Secondary ion mass spectrometry;  Surface properties;  Temperature;  ToF-SIMS;  Ultrasensitive probing;  X ray photoelectron spectroscopy;  XPS

Publisher

Elsevier

ISSN

0142-9612

Publisher URL

http://dx.doi.org/10.1016/s0142-9612(02)00228-4

Copyright

Copyright © 2002 Elsevier Science Ltd. All rights reserved.

Additional information

The authors acknowledge partial support for this research by the Australian Government under the Generic Technology component of the Industry Research and Development Act 1986 (GIRD Project 'Polymer Surface Engineering') and from the NIH (Grant No. RR-01296) to NESAC/BIO.

Peer reviewed