18 F-click labeling and preclinical evaluation of a new 18 F-folate for PET imaging

EJNMMI Research

Table 2 Ex vivo biodistribution studies of¹⁸ F-OEG-folate 12 in mice at various time points and¹⁸ F-click folate

	30 min p.i.	60 min p.i.	90 min p.i.	60 min p.i. blockade ^a	¹⁸ *F-click folate* 45 min p.i. ^b
	(n = 3)	(n = 3)	(n = 3)	(n = 3)	(n = 4)
%ID/g
Blood	0.20 ± 0.02	0.18 ± 0.01	0.16 ± 0.02	0.04 ± 0.01	0.13 ± 0.01
Heart	1.81 ± 0.61	1.09 ± 0.07	0.79 ± 0.16	0.02 ± 0.01	0.90 ± 0.22
Lung	1.21 ± 0.15	1.02 ± 0.7	0.86 ± 0.17	0.04 ± 0.03	0.85 ± 0.04
Spleen	0.53 ± 0.14	0.49 ± 0.04	0.43 ± 0.08	0.06 ± 0.03	0.33 ± 0.12
Kidneys	41.80 ± 2.58	40.77 ± 4.34	41.04 ± 7.04	0.26 ± 0.08	16.53 ± 2.22
Stomach (empty)	2.18 ± 0.76	1.39 ± 0.13	0.96 ± 0.37	0.12 ± 0.11	2.50 ± 0.6
Intestines (empty)	23.52 ± 7.37	4.56 ± 2.31	1.92 ± 0.52	14.72 ± 19.32	19.59 ± 5.26
Feces	164.2 ± 72.5	29.48 ± 19.04	11.36 ± 4.29	105.5 ± 128.7	56.00 ± 27.64
Liver	5.24 ± 1.57	4.05 ± 0.67	2.30 ± 0.54	0.21 ± 0.09	1.71 ± 0.14
Gall bladder	309.3 ± 187.6	133.2 ± 67.38	55.13 ± n.d.	775.5 ± 206.5	667.4 ± 530.1
Muscle	1.91 ± 0.25	1.64 ± 0.46	1.17 ± 0.03	0.08 ± 0.09	n.d.
Bone	1.47 ± 0.05	1.13 ± 0.21	0.84 ± 0.16	0.06 ± 0.06	0.13 ± 0.01
Salivary glands	8.01 ± 1.16	9.28 ± 1.68	7.03 ± 1.98	0.20 ± 0.18	n.d.
Tumor	3.39 ± 0.54	3.39 ± 0.44	3.54 ± 0.68	0.19 ± 0.07	3.13 ± 0.83
Ratio of tumor to organ or tissue
Blood	16.81 ± 3.13	18.95 ± 2.68	22.72 ± 6.73		24,08 ± 0.82
Liver	0.69 ± 0.22	0.86 ± 0.19	1.55 ± 0.15		1.18 ± 0.69
Kidney	0.08 ± 0.02	0.08 ± 0.01	0.09 ± 0.01		0.19 ± 1.38

^aIn the blockade group, each animal received 100 μg/100 μL of folic acid in PBS 5 min before radiotracer injection; ^bbiodistribution data of the ¹⁸ F-click folate were taken from [15]. n.d., no data. Italicized entries reflect folate receptor-positive tissues/organs.