NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.
Molecular Imaging and Contrast Agent Database (MICAD) [Internet]. Bethesda (MD): National Center for Biotechnology Information (US); 2004-2013.
| Chemical name: | [99mTc(CO)3]+-Labeled anti-epidermal
growth factor receptor (HER2) affibody ZHER2:342 with a
tri-(histidine-glutamate) tag (HE)3 on the
N-terminal | |
| Abbreviated name: | [99mTc(CO)3]+-(HE)3-ZHER2:342 | |
| Synonym: | ||
| Agent Category: | Affibody (antibody) | |
| Target: | Epidermal growth factor receptor (HER2) | |
| Target Category: | Receptor | |
| Method of detection: | Single-photon emission computed tomography (SPECT); gamma planar imaging | |
| Source of signal / contrast: | 99mTc | |
| Activation: | No | |
| Studies: |
| No structure is available in PubChem. |
Background
[PubMed]
Overexpression of the epidermal growth factor receptor type 2 (HER2) is a characteristic feature of a variety of cancers, and HER2 levels in tumors (primary or metastatic) are often used to screen for patients who would benefit from anti-HER2 antibody (Ab) therapy (e.g., for breast cancer), to determine the efficacy of a treatment regimen, or to predict the prognostic outcome for a patient (1). Single-photon emission computed tomography (SPECT) or gamma planar imaging with 99mTc-labeled ligands that target HER2 are often used to detect, diagnose, and develop a treatment regimen for cancers that overexpress this receptor (2). Although many Abs (monoclonal, recombinant, etc.) and their derivatives (single-chain and monovalent or divalent Fab fragments, etc.) have been developed and approved for clinical use for the imaging or radioimmunotherapy of such cancers, these agents have limited efficacy because of their immunogenicity (development of Abs against the anti-HER2 Abs), pharmacokinetic properties (long circulating times), and inability to penetrate deep into tissue (due to the large size of ~150 kDa) (3). Therefore, investigators are constantly developing and evaluating new alternatives to the Ab-based imaging agents (3).
Recently, a small (~7 kDa) ZHER2:342 affibody was engineered (4) and labeled with radionuclides such as 99mTc or 111In for the detection of HER2-overexpressing tumors with the use of SPECT (2). Later, the affibody and several of its structural derivatives were labeled with 99mTc and used to detect HER2-expressing cancers under preclinical and clinical conditions (for details on the structural derivatives, see Ekblad et al.) (5, 6). It has been shown that a hexa-histidine tag (H6; also facilitates purification of the H6-bearing compound by immobilized metal ion affinity chromatography) bearing dimeric ZHER2:342 could be labeled with 99mTc-tricarbonyl ([99mTc(CO)3]+) to obtain [99mTc(CO)3]+-H6-(ZHER2:342)2, and that the radiochemical was suitable to visualize the expression of HER2 in tumor-bearing mice (7). However, for the duration of the study, a higher amount of radioactivity was observed to accumulate in the liver compared to the tumors. From these observations the investigators concluded that, because the liver is often the organ to which a cancer metastasizes, H6-(ZHER2:342)2 was suitable only for the imaging of extrahepatic tumors. Other investigators have also shown that an H6 tag located on the N-terminal on a 99mTc-labeled anti-HER2 affibody leads to increased accumulation of label in the hepatic tissue (8, 9). On the basis of a hypothesis that the uptake of the labeled compound by the liver could be reduced by moving the H6 tag from the N-terminal of the ZHER2:342 affibody or by increasing the hydrophilicity of the tag, two new tracers were constructed by Tolmachev et al. (10). In one construct, the H6 tag was moved from the N-terminal of the affibody to the C-terminal to obtain ZHER2:342-H6; in the second construct, the tag located on the N-terminal of the affibody was made more hydrophilic by alternating glutamatic acid residues with the histidines to generate HEHEHE ((HE)3) and obtain (HE)3-ZHER2:342. These constructs were subsequently labeled with [99mTc(CO)3]+ to form [99mTc(CO)3]+-ZHER2:342-H6 and [99mTc(CO)3]+-(HE)3-ZHER2:342, respectively. The biodistribution patterns of these radiolabeled affibodies were respectively studied in normal and LS174T (a human colon cancer cell line that has a low expression of HER2) xenograft tumor-bearing nude mice and compared to that of the parent affibody, ZHER2:342 (described previously in (11)), which had an H6 tag on the N-terminal and was labeled with [99mTc(CO)3]+ ([99mTc(CO)3]+-H6-ZHER2:342). This chapter describes the results obtained with [99mTc(CO)3]+-(HE)3-ZHER2:342 and are compared to those obtained with [99mTc(CO)3]+-H6-ZHER2:342 and [99mTc(CO)3]+-ZHER2:342-H6. Results obtained with [99mTc(CO)3]+-H6 -ZHER2:342 and [99mTc(CO)3]+-ZHER2:342-H6 are described in separate chapters of MICAD (www.micad.nih.gov) (12, 13).
Other Sources of Information
Affibody ZHER2:342 chapters in MICAD
Other EGFR imaging agents in MICAD.
EGFR (human) ligands in PubMed.
Human EGFR in OMIM (Online Mendelian Inheritance in Man).
Information on EGFR (human) gene.
Protein and nucleotide information regarding EGFR.
Anti-EGFR antibody clinical trials
EGFR pathways in Pathways Interaction Database
Synthesis
[PubMed]
The production and purification of H6-ZHER2:342, ZHER2:342-H6, and (HE)3-ZHER2:342 were performed as described by Tolmachev et al. (10). The purity of the two hexa-histidine- and the (HE)3-linked affibodies was reported to be 98%. The molecular weights of H6-ZHER2:342, ZHER2:342-H6, and (HE)3- ZHER2:342 were reported to be 8.2 kDa, 7.873 kDa, and 7.836 kDa, respectively. Labeling of the tagged affibodies with [99mTc(CO)3]+ was also described by Tolmachev et al. (10). The radiochemical yield and purity of the three tracers were 80% and >95%, respectively. The specific activities of the three labeled affibodies were 14–15.8 GBq/μmol (378–426 mCi/μmol). Radio-colloid formation in the final preparation of each radiolabeled affibody was <1.5% as determined with reversed-phase high-performance liquid chromatography.
In Vitro Studies: Testing in Cells and Tissues
[PubMed]
[99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 were reported to be stable in phosphate-buffered saline for at least 24 h at room temperature (23°C). At the end of incubation, 98.5 ± 0.8%, 97.2 ± 0.2%, and 96.7 ± 0.0% of [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6, respectively, were reported to be intact as determined with instant thin-layer chromatography (10). A challenge with 500- or 1,000-fold excess histidine at 37°C for 1 h showed that >98% of [99mTc(CO)3]+-(HE)3-ZHER2:342 and [99mTc(CO)3]+-H6-ZHER2:342 and >95% of [99mTc(CO)3]+-ZHER2:342-H6 was intact at the end of the incubation period. The association equilibrium constant (KD), the association rate constant (Ka), and the dissociation rate constant (Kd) for [99mTc(CO)3]+-(HE)3-ZHER2:342 were 18 pM, 7.0 × 106 M-1s-1, and 1.2 × 10-4 s-1, respectively, as determined with biosensor analysis.
Using SKOV-3 (an ovarian cancer cell line with high expression of HER2), DU-145 (a prostate cancer cell line that has a low expression of HER2), and PC-3 (another prostate cancer cell line that has a low expression of HER2) cells, the receptor-binding specificity values of the labeled affibodies were reported to be 48.0 ± 2.0, 3.19 ± 0.04, and 3.0 ± 0.2, respectively, for [99mTc(CO)3]+-(HE)3-ZHER2:342; 48.9 ± 0.8%, 6.1 ± 0.2%, and 6.7 ± 0.1%, respectively, for [99mTc(CO)3]+-H6-ZHER2:342; and 46.0 ± 2.0%, 9.0 ± 0.4%, and 6.8 ± 1.0%, respectively, for [99mTc(CO)3]+-ZHER2:342-H6 (10). Pretreatment of the cells with 1,000-fold excess unlabeled H6-ZHER2:342 reduced the receptor binding on the SKOV-3, DU-145, and PC-3 cells significantly (P < 0.0005) to 0.9 ± 0%, 1.4 ± 0.3%, and 0.8 ± 0.1%, respectively, for [99mTc(CO)3]+-(HE)3-ZHER2:342; to 2.3 ± 0.5%, 3.0 ± 0.3%, and 3.6 ± 0.1%, respectively, for [99mTc(CO)3]+-H6-ZHER2:342; and 3.0 ± 0.1%, 3.1 ± 0.2%, and 3.4 ± 0.2%, respectively, for [99mTc(CO)3]+-ZHER2:342-H6. Cellular internalization of [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 by the SKOV-3 cells after 24 h incubation at 37°C was determined to be 65.3 ± 1.1%, 80.1 ± 0.5%, and 47.7 ± 0.1%, respectively. The antigen binding capacity of [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 in the presence of 100-fold excess receptor concentration (using intact SKOV-3 cells) was reported to be 70.3 ± 7.3%, 79.6 ± 0.6%, and 80.5 ± 0.4%, respectively. Similar antigen binding specificities have been reported by other investigators for 99mTc-labeled affibodies (1).
Animal Studies
Rodents
[PubMed]
The biodistribution patterns of [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 were studied in normal male Naval Medical Research Institute (NMRI) mice (n = 4 animals/time point) after intravenous injection of the respective tracers as described by Tolmachev et al. (10). Accumulated radioactivity in various organs of the animals was determined at 4 h and 24 h postinjection (p.i.) and was presented as percent of injected dose per gram tissue (% ID/g). In the blood, the radioactivity levels from [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 were 0.28 ± 0.04% ID/g, 0.19 ± 0.06% ID/g, and 0.9 ± 0.4% ID/g, respectively, at 4 h p.i.; this decreased to 0.10 ± 0.02% ID/g, 0.07 ± 0.02% ID/g, and 0.19 ± 0.04% ID/g, respectively, by 24 h p.i. At 4 h p.i., the kidneys had uptake values of 80.0 ± 4.0% ID/g, 92.0 ± 23.0% ID/g, and 100.0 ± 16.0% ID/g radioactivity from [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6, respectively. By 24 h p.i., the kidney uptake values had decreased to 43.0 ± 6.0% ID/g, 45.0 ± 6.0% ID/g, and 56.0 ± 10.0%, respectively. In the liver, the accumulations of the label from [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 at 4 h p.i. was 0.9 ± 0.2% ID/g, 10.0 ± 3.0% ID/g, and 5.0 ± 1.0% ID/g, respectively; by 24 h p.i., the tracer levels decreased to 0.61 ± 0.08% ID/g, 7.0 ± 1.0% ID/g, and 2.9 ± 0.5% ID/g, respectively. The reduced accumulation of [99mTc(CO)3]+-(HE)3-ZHER2:342 in the liver was attributed to the lower hydrophobicity at the N-terminal of the affibody due to the presence of the (HE)3 tag (1). At 4 h p.i., the uptake values in the spleen were 0.17 ± 0.03% ID/g, 1.3 ± 0.3% ID/g, and 0.8 ± 0.1% ID/g with [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6, respectively; by 24 h p.i., the accumulation in this organ decreased to 0.10 ± 0.02% ID/g, 0.8 ± 0.1% ID/g, and 0.47 ± 0.07% ID/g, respectively. All other organs showed uptake of <1.0% ID/g radioactivity from the three tracers at both time points. These observations indicated that radioactivity from the three labeled affibodies was rapidly cleared from the blood and was excreted primarily through the kidneys. The study also showed that, compared to [99mTc(CO)3]+-H6-ZHER2:342, approximately 2-fold and 10-fold less radioactivity accumulated in the liver with [99mTc(CO)3]+-ZHER2:342-H6 and [99mTc(CO)3]+-(HE)3-ZHER2:342, respectively; however, clearance of the latter labels from the blood was slower than the former (10). No in vivo blocking studies were reported with any of the radiolabeled affibodies.
In another study, the biodistribution patterns of [99mTc(CO)3]+-(HE)3-ZHER2:342, [99mTc(CO)3]+-H6-ZHER2:342, and [99mTc(CO)3]+-ZHER2:342-H6 were investigated in NMRI nude mice (n = 4 animals/group) bearing LS174T cell xenograft tumors (10). The uptake values of [99mTc(CO)3]+-(HE)3-ZHER2:342 in the kidneys, liver, and the xenograft tumors at 4 h p.i. were 70.0 ± 10.0% ID/g, 0.88 ± 0.05% ID/g, and 2.6 ± 0.4% ID/g, respectively, and the T/B, T/L, T/K, and T/M ratios were 81.0 ± 2.0, 3.0 ± 0.5, 0.038 ± 0.009, and 40.0 ± 3.0, respectively. At 4 h p.i., the accumulations of radioactivity from [99mTc(CO)3]+-H6-ZHER2:342 in the kidneys, liver, and the xenograft tumors were 82.0 ± 9.0% ID/g, 8.1 ± 0.8% ID/g, and 2.2 ± 0.3% ID/g, respectively. The tumor/blood (T/B), tumor/liver (T/L), tumor/kidney (T/K), and the tumor/muscle (T/M) ratios with this tracer were 4.5 ± 0.1, 0.29 ± 0.04, 0.028 ± 0.002, and 21.0 ± 0.2, respectively. For [99mTc(CO)3]+-ZHER2:342-H6, the label uptake values in the kidneys, liver, and the xenograft tumors were 67.0 ± 13.0% ID/g, 4.3 ± 0.8% ID/g, and 3.2 ± 0.9% ID/g, respectively, and the T/B, T/L, T/K, and T/M ratios were 3.0 ± 0.4, 0.7 ± 0.1, 0.047 ± 0.006, and 17.0 ± 3.0, respectively. This showed that, compared to [99mTc(CO)3]+-H6-ZHER2:342, there was higher tumor uptake of [99mTc(CO)3]+-ZHER2:342-H6 and [99mTc(CO)3]+-(HE)3-ZHER2:342, and the highest uptake was with the (HE)3 affibody. In addition, among the three labeled affibodies, [99mTc(CO)3]+-(HE)3-ZHER2:342 had the lowest uptake in the liver. This indicated that changing the location of the H6 tag from the N-terminal to the C-terminal or making the N-terminal tag of the affibody more hydrophilic reduced the uptake of radioactivity in the liver and other tissues but increased accumulation of the label in the HER2-positive tumors. No blocking studies with either tracer using the tumor-bearing mice were reported.
Gamma planar imaging of a tumor-bearing mouse showed that the uptake patterns of [99mTc(CO)3]+-(HE)3-ZHER2:342 and [99mTc(CO)3]+-H6-ZHER2:342 in the animals were similar to those observed during the biodistribution studies (10). However, it was clear from the images that the accumulation of radioactivity in the tumors was higher with [99mTc(CO)3]+-(HE)3-ZHER2:342 than with [99mTc(CO)3]+-H6-ZHER2:342. No imaging studies were reported with [99mTc(CO)3]+-ZHER2:342-H6.
References
- 1.
- Tolmachev V., Rosik D., Wallberg H., Sjoberg A., Sandstrom M., Hansson M., Wennborg A., Orlova A. Imaging of EGFR expression in murine xenografts using site-specifically labelled anti-EGFR 111In-DOTA-Z EGFR:2377 Affibody molecule: aspect of the injected tracer amount. Eur J Nucl Med Mol Imaging. 2010;37(3):613–22. [PubMed: 19838701]
- 2.
- Orlova A., Feldwisch J., Abrahmsen L., Tolmachev V. Update: affibody molecules for molecular imaging and therapy for cancer. Cancer Biother Radiopharm. 2007;22(5):573–84. [PubMed: 17979560]
- 3.
- Holliger P., Hudson P.J. Engineered antibody fragments and the rise of single domains. Nat Biotechnol. 2005;23(9):1126–36. [PubMed: 16151406]
- 4.
- Wahlberg E., Lendel C., Helgstrand M., Allard P., Dincbas-Renqvist V., Hedqvist A., Berglund H., Nygren P.A., Hard T. An affibody in complex with a target protein: structure and coupled folding. Proc Natl Acad Sci U S A. 2003;100(6):3185–90. [PMC free article: PMC152267] [PubMed: 12594333]
- 5.
- Tolmachev V., Friedman M., Sandstrom M., Eriksson T.L., Rosik D., Hodik M., Stahl S., Frejd F.Y., Orlova A. Affibody molecules for epidermal growth factor receptor targeting in vivo: aspects of dimerization and labeling chemistry. J Nucl Med. 2009;50(2):274–83. [PubMed: 19164241]
- 6.
- Ekblad T., Orlova A., Feldwisch J., Wennborg A., Karlstrom A.E., Tolmachev V. Positioning of 99mTc-chelators influences radiolabeling, stability and biodistribution of Affibody molecules. Bioorg Med Chem Lett. 2009;19(14):3912–4. [PubMed: 19364646]
- 7.
- Orlova A., Nilsson F.Y., Wikman M., Widstrom C., Stahl S., Carlsson J., Tolmachev V. Comparative in vivo evaluation of technetium and iodine labels on an anti-HER2 affibody for single-photon imaging of HER2 expression in tumors. J Nucl Med. 2006;47(3):512–9. [PubMed: 16513621]
- 8.
- Ahlgren S., Orlova A., Rosik D., Sandstrom M., Sjoberg A., Baastrup B., Widmark O., Fant G., Feldwisch J., Tolmachev V. Evaluation of maleimide derivative of DOTA for site-specific labeling of recombinant affibody molecules. Bioconjug Chem. 2008;19(1):235–43. [PubMed: 18163536]
- 9.
- Ahlgren S., Wallberg H., Tran T.A., Widstrom C., Hjertman M., Abrahmsen L., Berndorff D., Dinkelborg L.M., Cyr J.E., Feldwisch J., Orlova A., Tolmachev V. Targeting of HER2-expressing tumors with a site-specifically 99mTc-labeled recombinant affibody molecule, ZHER2:2395, with C-terminally engineered cysteine. J Nucl Med. 2009;50(5):781–9. [PubMed: 19372467]
- 10.
- Tolmachev V., Hofstrom C., Malmberg J., Ahlgren S., Hosseinimehr S.J., Sandstrom M., Abrahmsen L., Orlova A., Graslund T. HEHEHE-tagged affibody molecule may be purified by IMAC, is conveniently labeled with [(m)Tc(CO)](+), and shows improved biodistribution with reduced hepatic radioactivity accumulation. Bioconjug Chem. 2010;21(11):2013–22. [PubMed: 20964447]
- 11.
- Orlova A., Magnusson M., Eriksson T.L., Nilsson M., Larsson B., Hoiden-Guthenberg I., Widstrom C., Carlsson J., Tolmachev V., Stahl S., Nilsson F.Y. Tumor imaging using a picomolar affinity HER2 binding affibody molecule. Cancer Res. 2006;66(8):4339–48. [PubMed: 16618759]
- 12.
- Chopra, A., [99mTc(CO)3]+-Labeled anti-epidermal growth factor receptor (HER2) affibody ZHER2:342 with a hexa-histidine tag (H6) on the N-terminal. Molecular Imaging and Contrast agent Database (MICAD) [database online]. National Library of Medicine, NCBI, Bethesda, MD, USA. Available from www
.micad.nih.gov, 2004 -to current. - 13.
- Chopra, A., [99mTc(CO)3]+-Labeled anti-epidermal growth factor receptor (HER2) affibody ZHER2:342 with a hexa-histidine tag (H6) on the C-terminal. Molecular Imaging and Contrast agent Database (MICAD) [database online]. National Library of Medicine, NCBI, Bethesda, MD, USA. Available from www
.micad.nih.gov, 2004 -to current.
- Review [(99m)Tc(CO)(3)](+)-Labeled anti-epidermal growth factor receptor (HER2) affibody Z(HER2:342) with a hexa-histidine tag (H(6)) on the N-terminal.[Molecular Imaging and Contrast...]Review [(99m)Tc(CO)(3)](+)-Labeled anti-epidermal growth factor receptor (HER2) affibody Z(HER2:342) with a hexa-histidine tag (H(6)) on the N-terminal.Chopra A. Molecular Imaging and Contrast Agent Database (MICAD). 2004
- Review [(99m)Tc(CO)(3)](+)-Labeled anti-epidermal growth factor receptor (HER2) affibody Z(HER2:342) with a hexa-histidine tag (H(6)) on the C-terminal.[Molecular Imaging and Contrast...]Review [(99m)Tc(CO)(3)](+)-Labeled anti-epidermal growth factor receptor (HER2) affibody Z(HER2:342) with a hexa-histidine tag (H(6)) on the C-terminal.Chopra A. Molecular Imaging and Contrast Agent Database (MICAD). 2004
- Review (111)In/(125)I/(99m)Tc-Labeled N-terminus tri-(histidine-glutamate) (HE)(3)-tagged and N- or C-terminus hexahistidine (H6)-tagged anti-epidermal growth factor receptor Affibody Z(HER2:342)-C.[Molecular Imaging and Contrast...]Review (111)In/(125)I/(99m)Tc-Labeled N-terminus tri-(histidine-glutamate) (HE)(3)-tagged and N- or C-terminus hexahistidine (H6)-tagged anti-epidermal growth factor receptor Affibody Z(HER2:342)-C.Chopra A. Molecular Imaging and Contrast Agent Database (MICAD). 2004
- Review (99m)Tc-Labeled N(ε49) mercaptoacetyl derivatives of affibody Z(HER2:342) targeting the human epidermal growth factor receptor.[Molecular Imaging and Contrast...]Review (99m)Tc-Labeled N(ε49) mercaptoacetyl derivatives of affibody Z(HER2:342) targeting the human epidermal growth factor receptor.Chopra A. Molecular Imaging and Contrast Agent Database (MICAD). 2004
- Review (111)In/(68)Ga-Labeled anti-epidermal growth factor receptor, native chemical ligation cyclized Affibody Z(HER2:342min).[Molecular Imaging and Contrast...]Review (111)In/(68)Ga-Labeled anti-epidermal growth factor receptor, native chemical ligation cyclized Affibody Z(HER2:342min).Chopra A. Molecular Imaging and Contrast Agent Database (MICAD). 2004
- Recombinant adenovirus with enhanced green fluorescent protein - Molecular Imagi...Recombinant adenovirus with enhanced green fluorescent protein - Molecular Imaging and Contrast Agent Database (MICAD)
- 111In-CHX-A”-Rhenium-cyclized-[Cys3,4,10,D-Phe7,Arg11]α-MSH3-13 - Molecular Imag...111In-CHX-A”-Rhenium-cyclized-[Cys3,4,10,D-Phe7,Arg11]α-MSH3-13 - Molecular Imaging and Contrast Agent Database (MICAD)
- [99mTc(CO)3]+-Labeled anti-epidermal growth factor receptor (HER2) affibody ZHER...[99mTc(CO)3]+-Labeled anti-epidermal growth factor receptor (HER2) affibody ZHER2:342 with a tri-(histidine-glutamate) peptide tag (HE)3 on the N-terminal - Molecular Imaging and Contrast Agent Database (MICAD)
- 111In-BZ-Diethylenetriaminepentaacetic acid-ZEGFR:1907 - Molecular Imaging and C...111In-BZ-Diethylenetriaminepentaacetic acid-ZEGFR:1907 - Molecular Imaging and Contrast Agent Database (MICAD)
- 2'-Fluoro-2'-deoxy-5'-[123/124/125/131I]iodo-1β-d-arabinofuranosyluracil - Molec...2'-Fluoro-2'-deoxy-5'-[123/124/125/131I]iodo-1β-d-arabinofuranosyluracil - Molecular Imaging and Contrast Agent Database (MICAD)
Your browsing activity is empty.
Activity recording is turned off.
See more...