TABLE 5

Biodistribution of ^99mTc-Z_HER2_:V1 and ^99mTc-Z_HER2_:V2 Affibody Molecules in Male NMRI nu/nu Mice Bearing DU-145 Xenografts at 4 Hours After Intravenous Injection

	Uptake (%IA/g)		Tumor-to-organ ratio
Organ	^99mTc-Z_HER2_:V1	^99mTc-Z_HER2_:V2	^99mTc-Z_HER2_:V1	^99mTc-Z_HER2_:V2
Blood	0.21 ± 0.02^*	0.15 ± 0.02	31 ± 4^*	52 ± 6
Lung	0.467 ± 0.122	0.34 ± 0.05	15 ± 4	23 ± 6
Liver	1.0 ± 0.2	0.9 ± 0.1	6.4 ± 0.3^*	9 ± 1
Spleen	0.23 ± 0.07	0.21 ± 0.02	30 ± 7	37 ± 7
Stomach	0.21 ± 0.07	0.13 ± 0.02	36 ± 14^*	60 ± 4
Kidney	10.7 ± 1.4^*	3.5 ± 0.3	0.62 ± 0.04^*	2.2 ± 0.4
Salivary gland	0.15 ± 0.02^*	0.09 ± 0.01	45 ± 9^*	90 ± 21
Tumor	6.6 ± 0.7	7.7 ± 1.5
Muscle	0.055 ± 0.009	0.041 ± 0.008	123 ± 26	197 ± 59
Bone	0.20 ± 0.04	0.18 ± 0.04	34 ± 5^*	42 ± 4
Intestines^{^†}	2.2 ± 0.7	2.0 ± 1.5
Carcass^{^†}	2.7 ± 0.4	2.3 ± 0.4

↵* Significant difference between ^99mTc-Z_HER2_:V1 and ^99mTc-Z_HER2_:V2 Affibody molecules.
↵† Data for intestines with content and carcass are presented as percentage of injected radioactivity per whole sample.
%IA/g = percentage injected activity per gram of tissue.
Average tumor weight was 0.95 ± 0.06 g. Data are presented as average value from 4 animals ± SD.