Figure 2

Radiochemical purification of ^99mTc-HMPAO-ENVs and characteristics

. (a) ^99mTc-HMPAO and ^99mTc-HMPAO-ENVs were analyzed by instant thin layered chromatography (ITLC) using Whatman No. 1 paper. The radiochemical purify was analyzed right after removing ^99mTc-HMPAO. The radiochemical purify was more than 95%. (b) Average size distribution of non-labeled ENVs and ^99mTc-HMPAO-ENVs was examined by nanoparticle tracking analysis (NTA). There was no significant difference for the size distribution between non-labeled ENVs and ^99mTc-HMPAO-labeled ENVs. (c) An exosomal marker, CD63, was measured to check ENVs before and after ^99mTc-HMPAO radiolabeling by Western blot. Amount of exosomal protein in its expression was not changed, showing high expression of CD63 which was similar with protein expression in unlabeled ENVs. (d) Stability of ^99mTc-HMPAO-ENVs was examined in human serum and PBS. The level of stability was analyzed by ITLC.