Identification tests surface analysis

The capacity of the nanoparticles to adsorb proteins and to activate the complement in vivo after intravenous administration will influence the fate of the carrier and its body distribution. To approach this aspect, in vitro tests have been developed to investigate the profile of the type of serum proteins that adsorbed onto the nanoparticle surface after incubation in serum and to evaluate the capacity of the nanoparticles to induce complement activation. The analysis of the protein adsorbed onto the nanoparticle surface can be performed by 2D-polyacrylamide gel electrophoresis. This technique allows the identification of the proteins that adsorbed onto the nanoparticle surface. To evaluate modifications of the composition of the adsorbed protein with time, a faster method based on capillary electrophoresis can also be used. Finally, the activation of the complement produced by nanoparticles can be evaluated either by a global technique or by a specific method measuring the specific activation... 

In spite of such complications, magnetic sorting is used constantly in the field. Magnets can also be useful identification tools in conjunction with sophisticated quantitative instruments. For example, x-ray fluorescence analysis of a component showed it to be 100% chromium. This is because the technique utilizes only a very thin surface layer. A test with a magnet indicated attraction. It was concluded that the part was chrome plated and not solid chromium (which would have been very unlikely). 

---