by Keyword: ToF-SIMS
Michiardi, A., Helary, G., Nguyen, P. C. T., Gamble, L. J., Anagnostou, F., Castner, D. G., Migonney, V., (2010). Bioactive polymer grafting onto titanium alloy surfaces Acta Biomaterialia 6, (2), 667-675
Bioactive polymers bearing sulfonate (styrene sodium sulfonate, NaSS) and carboxylate (methylacrylic acid, MA) groups were grafted onto Ti6Al4V alloy surfaces by a two-step procedure. The Ti alloy surfaces were first chemically oxidized in a piranha solution and then directly subjected to radical polymerization at 70 °C in the absence of oxygen. The grafted surfaces were characterized by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and the toluidine blue colorimetric method. Toluidine blue results showed 1-5 μg cm-2 of polymer was grafted onto the oxidized Ti surfaces. Grafting resulted in a decrease in the XPS Ti and O signals from the underlying Ti substrate and a corresponding increase in the XPS C and S signals from the polymer layer. The ToF-SIMS intensities of the S- and SO- ions correlated linearly with the XPS atomic percent S concentrations and the ToF-SIMS intensity of the TiO3H2- ion correlated linearly with the XPS atomic per cent Ti concentration. Thus, the ToF-SIMS S-, SO- and TiO3H2- intensities can be used to quantify the composition and amount of grafted polymer. ToF-SIMS also detected ions that were more characteristic of the polymer molecular structure (C6H4SO3- and C8H7SO3- from NaSS, C4H5O2- from MA), but the intensity of these peaks depended on the polymer thickness and composition. An in vitro cell culture test was carried out with human osteoblast-like cells to assess the influence of the grafted polymers on cell response. Cell adhesion after 30 min of incubation showed significant differences between the grafted and ungrafted surfaces. The NaSS grafted surfaces showed the highest degree of cell adhesion while the MA-NaSS grafted surfaces showed the lowest degree of cell adhesion. After 4 weeks in vivo in rabbit femoral bones, bone was observed to be in direct contact with all implants. The percentage of mineralized tissue around the implants was similar for NaSS grafted and non-grafted implants (59% and 57%). The MA-NaSS grafted implant exhibited a lower amount of mineralized tissue (47%).
JTD Keywords: Bioactive polymers, Osteointegration, Titanium alloy, ToF-SIMS, XPS
Sporer, C., Casal, L., Caballero, D., Samitier, J., Errachid, A., Perez-Garcia, L., (2009). Novel anionophores for biosensor applications: nano characterisation of SAMS based on amphiphilic imidazolium protophanes and cyclophanes on gold surfaces Sensor Letters 
6th Maghreb-Europe Meeting on Materials and Their Applications for Devices and Physical, Chemical and Biological Sensors , AMER SCIENTIFIC PUBLISHERS (Rabat, Morocco) 7, (5), 757-764
Here we report on the results of surface deposition of the novel amphiphilic imidazolium heterocyclophanes and protophanes 1, 2, 3 onto gold electrodes by soft lithography and wet chemistry techniques. Depending on the specific functionalization conditions chosen, the surface properties and the pattern composition can vary widely. The formation of aggregates of monolayers or oligolayer structures and of rings with nano dimensioned wall widths has been investigated with Atomic Force Microscopy (AFM), Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Contact angle measurements.
JTD Keywords: Afm, Imidazolium anionophores, Microcontact printing, Tof-sims
