Analysis of stoichiometry and oxide growth of HF treated GaAs (100) by x-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry

1994 ◽  
Vol 12 (1) ◽  
pp. 147 ◽  
Author(s):  
W. Storm
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
Oxide Growth ◽  
X Ray ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Static time-of-flight secondary ion mass spectrometry and x-ray photoelectron spectroscopy characterization of adsorbed albumin and fibronectin films

2001 ◽  
Vol 31 (8) ◽  
pp. 724-733 ◽  
Author(s):  
Caren D. Tidwell ◽  
David G. Castner ◽  
Stephen L. Golledge ◽  
Buddy D. Ratner ◽  
Klaus Meyer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Time Of Flight ◽  
X Ray ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Surface Characterization of Lipid/Chitosan Nanoparticles Assemblies, Using X-Ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry

2008 ◽  
Vol 8 (1) ◽  
pp. 358-365 ◽  
Author(s):  
Ana Grenha ◽  
Begoña Seijo ◽  
Carmen Serra ◽  
Carmen Remuñán-López
Keyword(s):  
Mass Spectrometry ◽  
Drug Delivery ◽  
Photoelectron Spectroscopy ◽  
Secondary Ion Mass Spectrometry ◽  
Chitosan Nanoparticles ◽  
Time Of Flight ◽  
Lipid Film ◽  
X Ray ◽  
Ion Mass Spectrometry ◽  
Secondary Ion

Chitosan/tripolyphosphate nanoparticles are promising drug delivery systems, which show excellent capacity for protein entrapment and improvement of mucosal peptide absorption. We have recently developed a new drug delivery system consisting of assemblies formed between preformed chitosan nanoparticles and phospholipids (dipalmitoylphosphatidylcholine and dimiristoylphosphatidyl-glycerol) which are endogenous to the lung. These assemblies are prepared by lipid film hydration with a nanoparticles suspension. The aim of this work was to elucidate the architecture of these structures using sensitive surface analysis techniques such as X-ray photoelectron spectroscopy and static time-of-flight secondary ion mass spectrometry, as well as to determine their physicochemical characteristics. The combination of zeta potential measurements with the results obtained by X-ray photoelectron spectroscopy and static time-of-flight secondary ion mass spectrometry, demonstrated that a complete lipid coating of the nanoparticles can be achieved using a lipid film formed by both dipalmitoylphosphatidylcholine and dimiristoylphosphatidylglycerol, this way conferring to the lipid film a strong negative charge, which favors the interaction with the positively charged nanoparticles. Therefore, the major role of electrostatic interactions as driving forces to control the organisation of the lipid/nanoparticles assemblies was clearly evident. The implications of these findings for the structural organisation of the assemblies, for their in vitro behaviour, as well as for their mechanism of formation are discussed.

Sign in / Sign up

Export Citation Format

Share Document