Characterizing multicomponent adsorbed protein films using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry, and radiolabeling: capabilities and limitations

Citation

Wagner, M. S.; Horbett, T. A.; & Castner, David G. (2003). Characterizing multicomponent adsorbed protein films using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry, and radiolabeling: capabilities and limitations. Biomaterials, 24(11), 1897-1908.

Abstract

Characterization of complex adsorbed protein films is a critical aspect of biomaterials science, particularly in understanding the in vivo response to biomaterials. The surface analysis techniques electron spectroscopy for chemical analysis (ESCA) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) are particularly suited to the analysis of complex adsorbed protein films due to their wide applicability to a variety of materials. We have investigated the applicability of ESCA for studying the structure of adsorbed serum and plasma protein layers. ESCA was able to monitor the thickness of the adsorbed protein film. Due to its chemical specificity, ToF-SIMS was used to estimate the composition of the plasma and serum protein layers by comparison of their spectra with the spectra of single protein films. The limit of detection of ToF-SIMS for the plasma protein fibrinogen was determined by comparison with independent radiolabeled fibrinogen adsorption measurements. While ToF-SIMS was able to determine some qualitative trends in the composition of the plasma protein films as a function of adsorption time, the detection limit of the minor components in multicomponent adsorbed protein films ultimately limits the ability of ToF-SIMS to quantify the composition of these films. However, both ESCA and ToF-SIMS can provide useful information on adsorbed plasma protein films without further sample treatment. This study outlines the strengths and weaknesses of ESCA and ToF-SIMS for studying multicomponent adsorbed plasma protein films.

Keyword(s)

Adsorption
Aluminum Silicates
Biocompatible Materials
Blood Proteins
Electron Probe Microanalysis
Fibrinogen
Humans
Isotope Labeling
Protein Binding
Reproducibility of Results
Sensitivity and Specificity
Spectrometry, Mass, Secondary Ion
Surface Properties

Reference Type

Journal Article

Secondary Title

Biomaterials

Author(s)

Wagner, M. S.
Horbett, T. A.
Castner, David G.

Year Published

2003

Volume Number

Issue Number

Pages

1897-1908

DOI

Characterizing multicomponent adsorbed protein films using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry, and radiolabeling