ABSTRACT
For diagnostic purpose, particles can be labeled with radionuclides or contain magnetizable materials making them suitable for external measurements of their biokinetics in vivo. Particles in the submicrometer size range are referred to as nanoparticles whereas larger particles will be called microparticles. Characterization of radiolabeled nanoparticles includes several physical, chemical, and radiochemical parameters. Very few articles concerning the physicochemical properties of different colloids have been published. The ultrastructure of lymphatic capillaries resembles that of blood capillaries, but is usually wider in their lumina. The bulk of materials absorbed enter the lymphatics through endothelial gaps; some of the smaller complexes such as proteins might also be transported to some extent by the vesicular route. The behavior of nanoparticles injected interstitially is strongly dependent on their size. D. Cohen pioneered biomedical applications of magnetometry with measurements of magnetic contamination in human lungs in 1973.
