CoCorp had 7% uptake, comparable to the 9% found for a
67 Ga citrate approach. In
another approach,
57 Co labeled hematoporphyrin 1 was developed and examined
for biodistribution studies in BWI0232 adenocarcinoma-bearing mice [24]. In vivo
distribution studies indicated that 24 h after intravenous administration, the ratios of
tumor-to-blood and tumor-to-muscle could discriminate tumorous tissues.
N
N
N
N
HO
OH
O
O
OH
OH
Co
*
1
3.3.2 Copper-64 for Porphyrin and Porphysome
Copper radionuclides have received attention in the field of radiopharmaceutical
research because of their favorable physical properties and availability [25].
Decades ago, attempts were made at tumor localization in mice bearing varieties of
tumors by using several
64 Cu labeled porphyrins [26, 27]. The biodistribution
of
67 Cu radiolabeled 5,10,15,20-tetrakis(4-carboxyphenyl)porphinato(
67 Cu)
(
67 Cu-TCPP) was examined in rat lymph nodes, surrounding muscle, fat and
blood [28]. Later, synthetic porphyrins such as N-benzyl-5,10,15,20-tetrakis
(4-carboxyphenyl)porphine
(NbzHTCPP)
2
and
N-4-nitrobenzyl-5(4-carboxyphenyl)-10,15,20-tris(4-sulfophenyl)porphine (N-bzHCS 3 P) 3 were
employed with radiocopper for antibody-mediated delivery [29, 30]. An anti-renal
cell carcinoma (RCC) antibody and A6H conjugated copper-67 labeled N-bzHCS 3 P
was used for biodistribution analysis in human RCC xenograft-bearing nude mice.
67 CuCS 3 P-A6H exhibited a tumor-to-blood ratio of over 16 after 45 h. Fluoro
substitution impacted pharmacokinetics of
64 Cu labeled 5,10,15,20-tetrakis(penta
fluoro phenyl) porphyrin ((
64 Cu)-TFPP) 4 and this compound was used for PET
Table 3.1 (continued)
Compound
Radioisotope Half-life
Application
References
Porphyrin
166
Ho
26.8 h
SPECT;
Biodistribution studies
[72]
Porphyrin
177
Lu
6.647 days
Tumor therapy
[93]
Porphyrin
177
Lu
6.647 days
Cancer Radiotherapy
[73]
3 Porphyrin and Phthalocyanine Radiolabeling
55