Table 1.

Biodistribution of^99mTc-UCMSC-EVs at 0.5 h, 1 h, 4 h and 24 h after intravenous administration.

Organ (mean ± std %ID/g, n = 6)	0.5hr	1hr	4hr	24hr
blood	1.61 ± 0.89	0.89 ± 0.66	0.37 ± 0.27	0.13 ± 0.03
brain	0.04 ± 0.03	0.03 ± 0.02	0.01 ± 0.01	0.01 ± 0.00
thyroid	1.31 ± 0.64	1.29 ± 0.65	1.06 ± 0.53	0.39 ± 0.21
heart	0.57 ± 0.26	0.34 ± 0.21	0.22 ± 0.17	0.15 ± 0.06
lung	3.97 ± 3.32	2.52 ± 1.62	5.95 ± 6.14	4.55 ± 6.95
liver	64.74 ± 39.99	63.06 ± 33.71	63.03 ± 37.54	53.60 ± 30.85
stomach	0.47 ± 0.19	0.46 ± 0.19	0.27 ± 0.07	0.15 ± 0.06
pancrease	0.22 ± 0.09	0.21 ± 0.21	0.12 ± 0.06	0.05 ± 0.02
spleen	75.68 ± 47.34	81.95 ± 50.92	63.94 ± 27.48	86.09 ± 38.19
intestine	0.45 ± 0.15	0.30 ± 0.15	0.18 ± 0.11	0.14 ± 0.04
kidney	3.66 ± 1.49	2.85 ± 1.3	2.13 ± 0.89	1.61 ± 0.25
skin	0.34 ± 0.25	0.20 ± 0.12	0.13 ± 0.05	0.12 ± 0.03
muscle	0.07 ± 0.03	0.06 ± 0.03	0.04 ± 0.03	0.02 ± 0.05
bone	3.71 ± 1.97	3.08 ± 1.62	3.21 ± 2.28	2.84 ± 0.88