Blood and Synovial Microparticles as Revealed by Atomic Force and Scanning Electron Microscope

Microvesicles which are pinched off the cell membrane can be considered extracellular organelles which mediate interaction between distal cells. They were suggested to play an important role in many diseases including autoimmune disorders, however, standard methods for their assessment have not yet been decided upon while their clinical relevance and the underlying mechanisms are yet unclear. We present a pilot study results involving atomic force microscope (AFM) and scanning electron microscope (SEM) images of the material isolated from peripheral blood of healthy donors and from synovial fluid of patients with psoriatic arthritis and rheumatoid arthritis, which is expected to contain microvesicles. Micrographs reveal in the samples isolated from blood the presence of globular and tubular structures which are most probably microvesicles while the identity of grain-like structures isolated from synovial fluid remains obscure. To the best of our knowledge the AFM and SEM images of the material isolated from synovial fluid are presented for the first time.