Figure 5.

Blood circulation, excretion and organ biodistribution profiles of membrane-labelled B16F10 exosomes in melanoma-bearing C57Bl/6 mice. The [¹¹¹In]DTPA group was injected with 0.02M DTPA complexed with 0.5-1MBq of ¹¹¹InCl₃ while the [¹¹¹In]DTPA- Exo_B16 group was injected with 1x10¹¹ [¹¹¹In]DTPA-Exo_B16 (0.5-1MBq). (A) Blood circulation profile of [¹¹¹In]DTPA and [¹¹¹In]DTPA-Exo_B16. 5 µl blood were taken via tail bleeding at 2 min, 5 min, 10 min, 30 min, 1 h, 4 h and 24 h following intravenous injection of each compound. (B) Excretion profile of [¹¹¹In]DTPA and [¹¹¹In]DTPA-Exo_B16 where urine and faeces were collected from the animals 24 h post-injection. (C) and (D) Organ biodistribution of [¹¹¹In]DTPA and [¹¹¹In]DTPA-Exo_B16 respectively. Animals were culled at 1 h, 4 h and 24 h post-injection, perfused with saline and their organs were excised for analysis by gamma counting. Inset shows the zoomed-in tumour accumulation values for each group. (E) Comparison of organ biodistribution of [¹¹¹In]DTPA and [¹¹¹In]DTPA-Exo_B16 24 h post-injection, where inset shows zoomed-in tumour accumulation values for each group. Values are normalised to organ weight and expressed as mean ± SD, where n=3 for each group. For (C), (D) and (E), statistical analyses were done on liver, spleen, kidneys and tumour (p*<0.05, p** < 0.01, p*** <0.001).