Quantitative analysis of tissue distribution of the B16BL6-derived exosomes using a streptavidin-lactadherin fusion protein and iodine-125-labeled biotin derivative after intravenous injection in mice.
We previously succeeded in the visualization of tissue distribution of B16BL6 cells-derived exosomes by labeling with Gaussia luciferase (gLuc)-LA, a fusion protein of gLuc (a reporter protein) and lactadherin (LA; an exosome-tropic protein). However, total amount of B16BL6-derived exosomes delivered to each organ could not be evaluated because of the reduction of luminescent signal from gLuc-LA. The aim of the present study was to quantitatively evaluate the tissue distribution of B16BL6-derived exosomes. To this end, we labeled B16BL6-derived exosomes with iodine-125 ((125) I) based on streptavidin (SAV)-biotin system. A plasmid vector encoding fusion protein, SAV-LA, was constructed, and B16BL6 cells were transfected with the plasmid to obtain SAV-LA-coupled exosomes. SAV-LA-coupled exosomes were incubated with (3-(125) I-iodobenzoyl) norbiotinamide ((125) I-IBB) to obtain (125) I-labeled B16BL6 exosomes. After intravenous injection of (125) I-labeled B16BL6 exosomes into mice, radioactivity quickly disappeared from the blood circulation. At 4 h, 28%, 1.6%, and 7% of the injected radioactivity/organ was detected in the liver, spleen, and lung, respectively. These results indicate that (125) I-labeling of exosomes using SAV-biotin system is a useful method to quantitatively evaluate the amount of exogenously administered exosomes delivered to each organ and that the liver is the major organ in the clearance of exogenously administered B16BL6-derived exosomes.
Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, 606-8501, Japan.
Masaki
M
Morishita
Yuki
Y
Takahashi
Makiya
M
Nishikawa
Kohei
K
Sano
Kana
K
Kato
Takuma
T
Yamashita
Takafumi
T
Imai
Hideo
H
Saji
Yoshinobu
Y
Takakura
D000818:Animals; D001710:Biotin / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D007275:Injections, Intravenous; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008546:Melanoma, Experimental; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism*; D019809:Streptavidin / Q000032:analysis / Q000378:metabolism*; D014018:Tissue Distribution / Q000187:drug effects / Q000502:physiology
D007457:Iodine Radioisotopes; D011993:Recombinant Fusion Proteins; D001710:Biotin; D019809:Streptavidin
biomaterials; clearance; exosome; lactadherin; nanoparticles; pharmacokinetics; phospholipids; quantitative analysis; radioisotope; streptavidin