Silicon-[ 18F]fluorine (Si- 18F) radiochemistry has recently emerged alongside other unconventional approaches such as aluminum- 18F and boron- 18F based labeling strategies, reshaping the landscape of modern 18F-radiochemistry. All these novel methodologies are driven by the demand for more convenient 18F-labeling procedures to further disseminate one of the most sophisticated imaging technologies, Positron Emission Tomography (PET). The PET methodology requires special radionuclides such as 18F (one of the most prominent examples) to be introduced into bioactive molecules. Si- 18F radiochemistry contributed greatly towards the development of new radiopharmaceuticals for PET imaging. Herein, we describe the radiochemical basics of Si- 18F bond formation, the application of Si- 18F tracers for PET imaging, and additionally, the inherent chemical intricacies of this methodology.
References
[1]
Wahl, R.L.; Buchanan, J.W. Principles and Practice of Positron Emission Tomography; Lippincott Williams & Wilkins: Philadelphia, USA, 2002.
[2]
Cai, L.S.; Lu, S.Y.; Pike, V.W. Chemistry with [18F]fluoride ion. Eur. J. Org. Chem. 2008, 2853–2873.
[3]
Schubiger, P.A.; Lehmann, L.; Friebe, M. Chemistry—The Driving Force in Molecular Imaging; Springer: Berlin Heidelberg, Germay, 2007; Volume 97, pp. 1291–1297.
Ting, R.; Adam, M.J.; Ruth, T.J.; Perrin, D.M. Arylfluoroborates and alkylfluorosilicates as potential PET imaging agents: High-yielding aqueous biomolecular F-18-labeling. J. Am. Chem. Soc. 2005, 127, 13094–13095.
[6]
Ting, R.; Harwig, C.; auf dem Keller, U.; McCormick, S.; Austin, P.; Overall, C.M.; Adam, M.J.; Ruth, T.J.; Perrin, D.M. Toward [18F]-labeled aryltrifluoroborate radiotracers: In vivo Positron Emission Tomography imaging of stable aryltrifluoroborate clearance in mice. J. Am. Chem. Soc. 2008, 130, 12045–12055.
[7]
Keller, U.A.D.; Bellac, C.L.; Li, Y.; Lou, Y.M.; Lange, P.F.; Ting, R.; Harwig, C.; Kappelhoff, R.; Dedhar, S.; Adam, M.J.; Ruth, T.J.; Benard, F.; Perrin, D.M.; Overall, C.M. Novel matrix metalloproteinase inhibitor [18F]marimastat-aryltrifluoroborate as a probe for in vivo Positron Emission Tomography imaging in cancer. Cancer Res. 2010, 70, 7562–7569.
[8]
McBride, W.J.; D’Souza, C.A.; Sharkey, R.M.; Karacay, H.; Rossi, E.A.; Chang, C.H.; Goldenberg, D.M. Improved 18F labeling of peptides with a fluoride-aluminum-chelate complex. Bioconjugate Chem. 2010, 21, 1331–1340, doi:10.1021/bc100137x.
[9]
McBride, W.J.; Sharkey, R.M.; Karacay, H.; D'Souza, C.A.; Rossi, E.A.; Laverman, P.; Chang, C.H.; Boerman, O.C.; Goldenberg, D.M. A novel method of 18F radiolabeling for PET. J. Nucl. Med. 2009, 50, 991–998, doi:10.2967/jnumed.108.060418.
[10]
Laverman, P.; McBride, W.J.; Sharkey, R.M.; Eek, A.; Joosten, L.; Oyen, W.J.G.; Goldenberg, D.M.; Boerman, O.C. A novel facile method of labeling octreotide with 18F-fluorine. J. Nucl. Med. 2010, 51, 454–461, doi:10.2967/jnumed.109.066902.
[11]
McBride, W.J.; D’Souza, C.A.; Karacay, H.; Sharkey, R.M.; Goldenberg, D.M. New lyophilized kit for rapid radiofluorination of peptides. Bioconjugate Chem. 2012, 23, 538–547, doi:10.1021/bc200608e.
[12]
McBride, W.J.; D’Souza, C.A.; Sharkey, R.M.; Goldenberg, D.M. The radiolabeling of proteins by the [18F]AlF method. Appl. Radiat. Isotopes 2012, 70, 200–204, doi:10.1016/j.apradiso.2011.08.013.
[13]
Mu, L.; Schubiger, A.P.; Ametamey, S.M. [18F]Fluorosilicon- and [18F]Fluoroboron-based biomolecules for PET imaging. Curr. Radiophar. 2010, 3, 224–242, doi:10.2174/1874471011003030224.
[14]
Ametamey, S.M.; Honer, M.; Schubiger, P.A. Molecular imaging with PET. Chem. Rev. 2008, 108, 1501–1516, doi:10.1021/cr0782426.
[15]
Schirrmacher, R.; Wangler, C.; Schirrmacher, E. Recent developments and trends in 18F-radiochemistry: Syntheses and applications. Mini-Rev. Org. Chem. 2007, 4, 317–329, doi:10.2174/157019307782411699.
[16]
Smith, G.E.; Sladen, H.L.; Biagini, S.C.G.; Blower, P.J. Inorganic approaches for radiolabelling biomolecules with fluorine-18 for imaging with Positron Emission Tomography. Dalton Trans 2011, 40, 6196–6205, doi:10.1039/c0dt01594f.
[17]
Miller, P.W.; Long, N.J.; Vilar, R.; Gee, A.D. Synthesis of C-11, F-18, O-15, and N-13 radiolabels for Positron Emission Tomography. Angew Chem. Int. Ed. 2008, 47, 8998–9033, doi:10.1002/anie.200800222.
[18]
Mamat, C.; Ramenda, T.; Wuest, F.R. Recent applications of click chemistry for the synthesis of radiotracers for molecular imaging. Mini-Rev. Org. Chem. 2009, 6, 21–34, doi:10.2174/157019309787316148.
[19]
Gens, T.A.; Wethington, J.A.; Brosi, A.R. The exchange of F-18 between metallic fluorides and silicon tetrafluoride. J. Phys. Chem.-Us 1959, 62, 1593–1593.
[20]
Poole, R.T.; Winfield, J.M. Radiotracers in fluorine chemistry. 4. F-18 exchange between labeled alkylfluorosilanes and fluorides, or fluoride methoxides, of Tungsten(Vi), Molybdenum(Vi), Tellurium(Vi), and Iodine(V). J. Chem. Soc. Dalton 1976, 1557–1560.
[21]
Winfield, J.M. Preparation and use of 18-fluorine labeled inorganic-compounds. J. Fluorine Chem. 1980, 16, 1–17, doi:10.1016/S0022-1139(00)85145-3.
[22]
Sanyal, D.K.; Winfield, J.M. Radiotracers in fluorine chemistry. 8. F-18 exchange-reactions involving Uranium(VI) or Uranium(V) fluorides—Evidence for surface complexation and comparisons with ligand-exchange reactions. J. Fluorine Chem. 1984, 24, 75–92, doi:10.1016/S0022-1139(00)81297-X.
[23]
Rosenthal, M.S.; Bosch, A.L.; Nickles, R.J.; Gatley, S.J. Synthesis and some characteristics of no-carrier added [18F]fluorotrimethylsilane. Int. J. Appl. Radiat. Isotop. 1985, 36, 318–319, doi:10.1016/0020-708X(85)90094-8.
[24]
Gatley, S.J. Rapid production and trapping of [18F] Fluorotrimethylsilane, and its use in nucleophilic fluorine-18 labeling without an aqueous evaporation step. Appl. Radiat. Isotope. 1989, 40, 541–544, doi:10.1016/0883-2889(89)90143-3.
[25]
Hamacher, K.; Coenen, H.H.; Stocklin, G. Efficient stereospecific synthesis of no-carrier-added 2-[18F]-Fluoro-2-deoxy-D-glucose using aminopolyether supported nucleophilic-substitution. J. Nucl. Med. 1986, 27, 235–238.
[26]
Walsh, J.C.; Fleming, L.M.; Satyamurthy, N.; Barrio, J.R.; Phelps, M.E.; Gambhir, S.S.; Toyokuni, T. Application of silicon-fluoride chemistry for the development of amine-reactive F-18-labeling agents for biomolecules. J. Nucl. Med 2000, 41, 249p–249p.
[27]
Choudhry, U.; Martin, K.E.; Biagini, S.; Blower, P.J. Alkoxysilane groups for instant labeling of biomolecules with 18F. Nucl. Med. Commun. 2006, 27.
[28]
Schirrmacher, R.; Bradtm？ller, G.; Schirrmacher, E.; Thews, O.; Tillmanns, J.; Siessmeier, T.; Buchholz, H.G.; Bartenstein, P.; W？ngler, B.; Niemeyer, C.M.; Jurkschat, K. 18F-labeling of peptides by means of an organosilicon-based fluoride acceptor. Angew Chem. Int. Ed. 2006, 45, 6047–6050.
[29]
Mu, L.J.; Hohne, A.; Schubiger, R.A.; Ametamey, S.M.; Graham, K.; Cyr, J.E.; Dinkelborg, L.; Stellfeld, T.; Srinivasan, A.; Voigtmann, U.; Klar, U. Silicon-based building blocks for one-step 18F-radiolabeling of peptides for PET imaging. Angew Chem. Int. Ed. 2008, 47, 4922–4925.
[30]
Schirrmacher, E.; Wangler, B.; Cypryk, M.; Bradtmoller, G.; Schafer, M.; Eisenhut, M.; Jurkschat, K.; Schirrmacher, R. Synthesis of p-(Di-tert-butyl[18F]fluorosilyl)benzaldehyde ([18F]SiFA-A) with high specific activity by isotopic exchange: A convenient Labeling synthon for the 18F-labeling of n-amino-oxy derivatized peptides. Bioconjugate Chem. 2007, 18, 2085–2089, doi:10.1021/bc700195y.
[31]
Tietze, L.F.; Schmuck, K. SiFA azide: A new building block for PET imaging using click chemistry. Synlett 2011, 1697–1700, doi:10.1055/s-0030-1260942.
[32]
Kostikov, A.P.; Iovkova, L.; Chin, J.; Schirrmacher, E.; Wangler, B.; Wangler, C.; Jurkschat, K.; Cosa, G.; Schirrmacher, R. N-(4-(di-tert-butyl[(18)F]fluorosilyl)benzyl)-2-hydroxy-N, N-dimethylethylammonium bromide ([18F]SiFAN+Br？): A novel lead compound for the development of hydrophilic SiFA-based prosthetic groups for (18)F-labeling. J. Fluorine Chem. 2011, 132, 27–34, doi:10.1016/j.jfluchem.2010.10.008.
[33]
Hohne, A.; Yu, L.; Mu, L.J.; Reiher, M.; Voigtmann, U.; Klar, U.; Graham, K.; Schubiger, P.A.; Ametamey, S.M. Organofluorosilanes as model compounds for 18F-labeled Silicon-based PET tracers and their hydrolytic stability: Experimental data and theoretical calculations (PET = Positron Emission Tomography). Chem. Eur. J. 2009, 15, 3736–3743.
[34]
Kiesewetter, D.O.; Jacobson, O.; Lang, L.X.; Chen, X.Y. Automated radiochemical synthesis of [18F]FBEM: A thiol reactive synthon for radiofluorination of peptides and proteins. Appl. Radiat. Isotopes 2011, 69, 410–414, doi:10.1016/j.apradiso.2010.09.023.
W？ngler, C.; Waser, B.; Alke, A.; Iovkova, L.; Buchholz, H.G.; Niedermoser, S.; Jurkschat, K.; Fottner, C.; Bartenstein, P.; Schirrmacher, R.; Reubi, J.C.; Wester, H.J.; W？ngler, B. One-step 18F-labeling of carbohydrate-conjugated octreotate-derivatives containing a Silicon-Fluoride-Acceptor (SiFA): In vitro and in vivo evaluation as tumor imaging agents for Positron Emission Tomography (PET). Bioconjugate Chem. 2010, 21, 2289–2296.
[39]
Iovkova, L.; Konning, D.; Wangler, B.; Schirrmacher, R.; Schoof, S.; Arndt, H.D.; Jurkschat, K. SiFA-modified phenylalanine: A key compound for the efficient synthesis of 18F-labelled peptides. Eur. J. Inorg. Chem. 2011, 2238–2246.
[40]
H？hne, A.; Mu, L.; Honer, M.; Schubiger, P.A.; Ametamey, S.M.; Graham, K.; Stellfeld, T.; Borkowski, S.; Berndorff, D.; Klar, U.; Voigtmann, U.; Cyr, J.E.; Friebe, M.; Dinkelborg, L.; Srinivasan, A. Synthesis, 18F-labeling, and in vitro and in vivo studies of bombesin peptides modified with silicon-based building blocks. Bioconjugate Chem. 2008, 19, 1871–1879, doi:10.1021/bc800157h.
[41]
Balentova, E.; Collet, C.; Lamande-Langle, S.; Chretien, F.; Thonon, D.; Aerts, J.; Lemaire, C.; Luxen, A.; Chapleur, Y. Synthesis and hydrolytic stability of novel 3-[[18F]fluoroethoxybis (1-methylethyl)silyl]propanamine-based prosthetic groups. J. Fluorine Chem. 2011, 132, 250–257, doi:10.1016/j.jfluchem.2011.01.011.
[42]
Schottelius, M.; Rau, F.; Reubi, J.C.; Schwaiger, M.; Wester, H.A. Modulation of pharmacokinetics of radioiodinated sugar-conjugated somatostatin analogues by variation of peptide net charge and carbohydration chemistry. Bioconjugate Chem. 2005, 16, 429–437, doi:10.1021/bc0499228.
[43]
Schottelius, M.; Wester, H.J.; Reubi, J.C.; Senekowitsch-Schmidtke, R.; Schwaiger, M. Improvement of pharmacokinetics of radioiodinated Tyr3-octreotide by conjugation with carbohydrates. Bioconjugate Chem. 2002, 13, 1021–1030, doi:10.1021/bc0200069.
[44]
Antunes, P.; Ginj, M.; Walter, M.A.; Chen, J.H.; Reubi, J.C.; Maecke, H.R. Influence of different spacers on the biological profile of a DOTA-somatostatin analogue. Bioconjugate Chem. 2007, 18, 84–92, doi:10.1021/bc0601673.
[45]
Rosa-Neto, P.; W？ngler, B.; Iovkova, L.; Boening, G.; Reader, A.; Jurkschat, K.; Schirrmacher, E. [18F]SiFA-isothiocyanate: A new highly effective radioactive labeling agent for lysine-containing proteins. Chembiochem 2009, 10, 1321–1324, doi:10.1002/cbic.200900132.
Schulz, J.; Vimont, D.; Bordenave, T.; James, D.; Escudier, J.M.; Allard, M.; Szlosek-Pinaud, M.; Fouquet, E. Silicon-based chemistry: An original and efficient one-step approach to [18F]-nucleosides and [18F]-oligonucleotides for PET imaging. Chem. Eur. J. 2011, 17, 3096–3100.
[48]
Iovkova-Berends, L.; Wangler, C.; Zoller, T.; Hofner, G.; Wanner, K.T.; Rensch, C.; Bartenstein, P.; Kostikov, A.; Schirrmacher, R.; Jurkschat, K.; Wangler, B. t-Bu2SiF-derivatized D2-receptor ligands: The first SiFA-containing small molecule radiotracers for target-specific PET-imaging. Molecules 2011, 16, 7458–7479.
