scholarly journals Comparative Study of NAP-XPS and Cryo-XPS for the Investigation of Surface Chemistry of the Bacterial Cell-Envelope

2021 ◽  
Vol 9 ◽  
Author(s):  
Marit Kjærvik ◽  
Madeleine Ramstedt ◽  
Karin Schwibbert ◽  
Paul M. Dietrich ◽  
Wolfgang E. S. Unger

Bacteria generally interact with the environment via processes involving their cell-envelope. Thus, techniques that may shed light on their surface chemistry are attractive tools for providing an understanding of bacterial interactions. One of these tools is Al Kα-excited photoelectron spectroscopy (XPS) with its estimated information depth of <10 nm. XPS-analyses of bacteria have been performed for several decades on freeze-dried specimens in order to be compatible with the vacuum in the analysis chamber of the spectrometer. A limitation of these studies has been that the freeze-drying method may collapse cell structure as well as introduce surface contaminants. However, recent developments in XPS allow for analysis of biological samples at near ambient pressure (NAP-XPS) or as frozen hydrated specimens (cryo-XPS) in vacuum. In this work, we have analyzed bacterial samples from a reference strain of the Gram-negative bacterium Pseudomonas fluorescens using both techniques. We compare the results obtained and, in general, observe good agreement between the two techniques. Furthermore, we discuss advantages and disadvantages with the two analysis approaches and the output data they provide. XPS reference data from the bacterial strain are provided, and we propose that planktonic cells of this strain (DSM 50090) are used as a reference material for surface chemical analysis of bacterial systems.

2018 ◽  
Vol 61 (20) ◽  
pp. 2175-2184 ◽  
Author(s):  
Ashley R. Head ◽  
Lena Trotochaud ◽  
Roman Tsyshevsky ◽  
Kenan Fears ◽  
Bryan Eichhorn ◽  
...  

2018 ◽  
Vol 10 (43) ◽  
pp. 37661-37670 ◽  
Author(s):  
Angelique Jarry ◽  
Sandrine Ricote ◽  
Aaron Geller ◽  
Christopher Pellegrinelli ◽  
Xiaohang Zhang ◽  
...  

2020 ◽  
Vol 152 (5) ◽  
pp. 054713 ◽  
Author(s):  
J. Trey Diulus ◽  
Radwan Elzein ◽  
Rafik Addou ◽  
Gregory S. Herman

1989 ◽  
Vol 12 (3) ◽  
pp. 189-194 ◽  
Author(s):  
R. W. Paynter ◽  
M. W. King ◽  
R. G. Guidoin ◽  
T. Rao

The importance of identifying and quantifying the level of contaminants on the surface of biomaterials has long been recognized as a significant step towards predicting the biocompatibility and rate of healing of implantable devices. Yet suitable techniques for characterizing the surface chemistry of soft and flexible biomaterials with an uneven surface contour such as those used in vascular prostheses have only recently been made available. As a first step towards determining the effect of surface contaminants on the healing behaviour of vascular prostheses, this study used X-ray photoelectron spectroscopy (XPS) to characterize the surface chemistry of 14 virgin polyester arterial prostheses from a wide variety of sources. Generally speaking, all surfaces appeared relatively clean. However, the results indicate that certain prostheses were not manufactured with Dacrorf-like fibres, and that some exhibit significantly carbon-rich surfaces. This suggests that the surface of these devices has been modified either by a hydrocarbon lubricant or by vapour phase hydrocarbons during fabrication.


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