制备，纯化和磁共振成像造影剂的使用稀土配合物的表征
Summary
我们展示metalation，净化，稀土配合物的特性。这里所描述的复合物，可以结合大分子，使这些分子利用磁共振成像进行跟踪。
Abstract
常用Polyaminopolycarboxylate基于配体螯合稀土离子，并由此产生的复合物作为磁共振成像（MRI）造影剂。许多市售的配体是特别有用，因为它们包含的功能组别，允许快速，高纯度和高产通过胺反应活性酯和异硫氰酸团体或巯基反应马来酰亚胺的大分子和生物分子共轭。虽然这些配体metalation bioconjugation化学细微的差别，在metalation程序方面的常识，必须考虑选择金属起始原料时。此外，纯化及鉴定的存在，并选择最有效的程序的多个选项部分取决于起始材料的选择。这些细微的差别往往被忽视发布的协议。在这里，我们的目标是展示metalation，纯化和特性，可作为MRI（图1）造影剂使用的稀土配合物的常用方法。我们期望本出版物将使生物医学科学家将其纳入自己的常用反应剧目稀土络合反应，由宽松的起始材料和净化方法的选择。
Protocol
1。 Metalation使用LnCl 3盐溶解在水中的配体产生30-265 mM的解决方案。在这个视频配体2 – （4 – isothiocyanatobenzyl）-二乙三胺五乙酸（P – SCN – BN – DTPA的）浓度在73毫米。 通过添加1个M NH 4 OH解决配体的pH值调整到5.5和7.0之间。在这段视频中，1米的NH 4 OH溶液0.2毫升。 溶解于水1-2 LnCl 3等值5-1000 mM的浓度与生产的解决方案。在这个视频，EuCl 3</s…
Discussion
鉴于越来越多的出版物，包括镧系元素的造影剂4-14，这是重要的准备，净化和表征产品，以确保重现性好，比较的结果，采取照顾。这些复合物通常被认为是具有挑战性的净化和表征有机分子由于其顺磁性质和任何可以使用bioconjugation的功能组别的敏感性相对。我们已经描述了稀土配合物的合成，纯化，并表征的常用方法。然而，选择其中一种方法时，重要的是要考虑的具体制度，正在?…
Declarações
The authors have nothing to disclose.
Acknowledgements
我们非常感谢来自韦恩州立大学（MJA），从美国的老龄化研究（SMV）基金会的赠款，并以独立职业过渡奖（R00EB007129）来自国家生物医学成像研究所和国家研究院生物的途径启动资金卫生（MJA）。
Materials
| Reagents and Equipment | Company | Catalogue number |
|---|---|---|
| EuCl3•6H2O | Sigma-Aldrich | 203254-5G |
| p-SCN-Bn-DTPA | Macrocyclics | B-305 |
| ammonium hydroxide | EMD | AX1303-3 |
| Spectra/Por Biotech Cellulose Ester (CE) Dialysis Membrane – 500 D MWCO | Fisher Scientific | 68-671-24 |
| Millipore IC Millex-LG Filter Units | Fisher Scientific | SLLG C13 NL |
| xylenol orange tetrasodium salt | Alfa Aesar | 41379 |
| acetic acid | Fluka | 49199 |
| D2O | Cambridge Isotope Laboratories, Inc. | DLM-4-25 |
| water purifier | ELGA | Purelab Ultra |
| high performance liquid chromatography and mass spectrometry | Shimadzu | LCMS-2010EV |
| relaxation time analyzer | Bruker | mq60 minispec |
| UV-vis spectrophotometer | Fisher Scientific | 20-624-00092 |
| freeze dryer | Fisher Scientific | 10-030-133 |
| pH meter | Hanna Instruments | HI 221 |
| spectrofluorometer | HORIBA Jobin Yvon | Fluoromax-4 |
| Molecular Weight Calculator version 6.46 by Matthew Monroe, downloaded October 17, 2009 | http://ncrr.pnl.gov/software/ | Molecular Weight Calculator |
Referências
- Barge, A., Cravotto, G., Gianolio, E., Fedeli, F. How to determine free Gd and free ligand in solution of Gd chelates. A technical note. Contrast Med. Mol. Imaging. 1, 184-188 (2006).
- Nagaraja, T. N., Croxen, R. L., Panda, S., Knight, R. A., Keenan, K. A., Brown, S. L., Fenstermacher, J. D., Ewing, J. R. Application of arsenazo III in the preparation and characterization of an albumin-linked, gadolinium-based macromolecular magnetic resonance contrast agent. J. Neurosci. Methods. 157, 238-245 (2006).
- Supkowski, R. M., Horrocks, W. D. On the determination of the number of water molecules, q, coordinated to europium(III) ions in solution from luminescence decay lifetimes. Inorg. Chim. Acta. 340, 44-48 (2002).
- Menjoge, A. R., Kannan, R. M., Tomalia, D. A. Dendrimer-based drug and imaging conjugates: design considerations for nanomedical applications. Drug Discovery Today. 15, 171-185 (2010).
- Que, E. L., Chang, C. J. Responsive magnetic resonance imaging contrast agents as chemical sensors for metals in biology and medicine. Chem. Soc. Rev. 39, 51-60 (2010).
- Uppal, R., Caravan, P. Targeted probes for cardiovascular MR imaging. Future Med. Chem. 2, 451-470 (2010).
- Major, J. L., Meade, T. J. Bioresponsive, cell-penetrating, and multimeric MR contrast agents. Acc. Chem. Res. 42, 893-903 (2009).
- Datta, A., Raymond, K. N. Gd-hydroxypyridinone (HOPO)-based high-relaxivity magnetic resonance imaging (MRI) contrast agents. Acc. Chem. Res. 42, 938-947 (2009).
- León-Rodríguez, L. M. D., Lubag, A. J. M., Malloy, C. R., Martinez, G. V., Gillies, R. J., Sherry, A. D. Responsive MRI agents for sensing metabolism in vivo. Acc. Chem. Res. 42, 948-957 (2009).
- Castelli, D. D., Gianolio, E., Crich, S. G., Terreno, E., Aime, S. Metal containing nanosized systems for MR-molecular imaging applications. Coord. Chem. Rev. 252, 2424-2443 (2008).
- Caravan, P., Ellison, J. J., McMurry, T. J., Lauffer, R. B. Gadolinium(III) chelates as MRI contrast agents: structure, dynamics, and applications. Chem. Rev. 99, 2293-2352 (1999).
- Lauffer, R. B. Paramagnetic metal complexes as water proton relaxation agents for NMR imaging: theory and design. Chem. Rev. 87, 901-927 (1987).
- Yoo, B., Pagel, An overview of responsive MRI contrast agents for molecular imaging. Front. Biosci. 13, 1733-1752 (2008).
- Pandya, S., Yu, J., Parker, D. Engineering emissive europium and terbium complexes for molecular imaging and sensing. Dalton Trans. 23, 2757-2766 (2006).
- Nwe, K., Xu, H., Regino, C. A. S., Bernardo, M., Ileva, L., Riffle, L., Wong, K. J., Brechbiel, M. W. A new approach in the preparation of dendrimer-based bifunctional diethylenetriaminepentaacetic acid MR contrast agent derivatives. Bioconjugate Chem. 20, 1412-1418 (2009).
- Nwe, K., Bernardo, M., Regino, C. A. S., Williams, M., Brechbiel, M. W. Comparison of MRI properties between derivatized DTPA and DOTA gadolinium-dendrimer conjugates. Bioorg. Med. Chem. 18, 5925-5931 (2010).
- Caravan, P., Das, B., Deng, Q., Dumas, S., Jacques, V., Koerner, S. K., Kolodziej, A., Looby, R. J., Sun, W. -. C., Zhang, Z. A lysine walk to high relaxivity collagen-targeted MRI contrast agents. Chem. Commun. , 430-432 (2009).
- León-Rodríguez, L. M. D., Kovacs, Z. The synthesis and chelation chemistry of DOTA-peptide conjugates. Bioconjugate Chem. 19, 391-402 (2008).
- Boswell, C. A., Eck, P. K., Regino, C. A. S., Bernardo, M., Wong, K. J., Milenic, D. E., Choyke, P. L., Brechbiel, M. W. Synthesis, characterization, and biological evaluation of integrin αVβ3-targeted PAMAM dendrimers. Mol. Pharm. 5, 527-539 (2008).
Tags
PreparationPurificationCharacterizationLanthanide ComplexesContrast AgentsMagnetic Resonance ImagingPolyaminopolycarboxylate-based LigandsChelateFunctional GroupsConjugationAmine-reactive Activated EstersIsothiocyanate GroupsThiol-reactive MaleimidesMetalation ProceduresMetal Starting MaterialsPurification MethodsBiomedical Scientists
Citar este artigo
Averill, D. J., Garcia, J., Siriwardena-Mahanama, B. N., Vithanarachchi, S. M., Allen, M. J. Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging. J. Vis. Exp. (53), e2844, doi:10.3791/2844 (2011).