| 研究課題/領域番号 |
26288023
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| 研究機関 | 名古屋大学 |
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研究代表者 |
CRUDDEN Cathleen 名古屋大学, トランスフォーマティブ生命分子研究所, 客員教授 (10721029)
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| 研究期間 (年度) |
2014-04-01 – 2017-03-31
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| キーワード | gold nanoparticle / N-heterocyclic carbene / gold nanocluster / bio-imaging |
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| 研究実績の概要 |
(i) Nanoparticles. We have been able to prepare several NHC-stabilized nanoparticles. Specifically, we have prepared nanoparticles stabilized by bidentate NHCs. These NHC-modified nanoparticles have been tested for thermal stability and show excellent results. We are currently testing all nanoparticles with thiols that will mimic biological thiols. Collaborations are in place for the testing of photoaccoustic properties for the coming year.
(ii) Nanoclusters. We have examined several different methods for the preparation of nanoclusters. We prepared Au nanoclusters stabilized by thiols and stabilized by phosphines and found that the phosphine-stabilized nanoclusters could be exchanged for carbenes. The most stable and well-characterized nanoclusters are those that have an Au11 core, and thus are relatively small. These clusters are currently being studied by the Tsukuda group at the University of Tokyo, world experts in the preparation and analysis of gold clusters.
We have also succeeded in making clusters from a bottom up approach, using NHC-Au-X starting materials, where X can be another NHC or a halide. After considerable experimentation, we found that a mixture of the charged (NHC)2Au+ and NHC-Au-Cl gave the best results. Cluster formation was initiated by reduction with NaBH4 and the clusters purified using bioanalytical techniques including centrifugation and ultrafiltration. In order to investigate the exact number of gold atoms and NHCs, we have given these clusters to the Tsukuda group for in depth profiling by mass spectrometry.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Progress-to-date has been very good. As noted above, we have made progress in the synthesis of stable nanoparticles functionalized by a variety of different NHCs. We are in the process of testing the stability of the NHC-functionalized nanoparticles. It has already been determined that NHC-protected nanoparticles with long alkyl chains have good thermal stability, and their stability against various reagents is in the process of being tested. Unfortunately since the alkyl chains render these nanoparticles dispersible in organic solvents such as toluene but insoluble in water we will have to prepare another type of nanoparticle with long alkyl chains containing terminal hydroxyl or carboxyl groups in order to properly test stability under biological conditions, and to do biosensing.
In the case of nanoclusters, we do have carboxyl-terminated nanoclusters that are dispersible in water and will test these for biological stability as described below. We had initial difficulties with the purification and analysis of these materials since our lab is not fully equipped with the instrumentation required for these tasks. However, the biology groups at our Institute have kindly permitted us to use many of there instrumentations and so we have been able to purify these unique nanoclusters. In addition, we have employed the characterization tools (TEM etc) from the Itami Erato team in order to better understand the nanoparticles and nanoclusters we have prepared.
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| 今後の研究の推進方策 |
In year three, we will fully characterize the nanoparticles and nanoclusters prepared thus far in our group. Water dispersible nanoparticles will be prepared, and along with the already dispersible nanoclusters, these will be tested for stability under high salt conditions, aqueous conditions, and in the presence of biological nucleophiles. Initially, we will just employ nanoparticles themselves injected into tissue samples, and eventually we plan to attach targeting agents to observe specific tumors in the body. In addition to the in vivo work, we will also more fully characterize the nanoclusters, including attempting crystallization such that the structure can be solved by single crystal X-ray crystallography. Finally, we will adjust the synthetic conditions and the structure of the N-heterocyclic carbenes to obtain the most stable nanoclusters suitable for in vivo imaging.
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| 次年度使用額が生じた理由 |
研究に従事してした博士研究員の退職により、当初予定していた研究使用額に差が生じたため
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| 次年度使用額の使用計画 |
研究用の試薬、器具の購入に使用する予定である。また生体イメージングへの応用研究に向け、抗体の購入やナノ粒子の精製為に利用する
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