Amphiphilic Cyclodextrins as Capping Agents for Gold Colloids: A Spectroscopic Investigation with Perspectives in Photothermal Therapy
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- 作者：Antonino Mazzaglia ; Mariachiara Trapani ; Valentina Villari ; Norberto Micali ; Francesca Marino Merlo ; Daniela Zaccaria ; Maria Teresa Sciortino ; Francesco Previti ; Salvatore Patanè ; Luigi Mons&ugr
- 刊名：Journal of Physical Chemistry C
- 出版年：2008
- 出版时间：May 1, 2008
- 年：2008
- 卷：112
- 期：17
- 页码：6764 - 6769
- 全文大小：165K
- 年卷期：v.112,no.17(May 1, 2008)
- ISSN：1932-7455
文摘
Amphiphilic cyclodextrins (CDs) modified in the upper rim with thiohexyl groups and in the lower rim witholigoethylene amino (SC6NH2) or oligoethylene hydroxyl groups (SC6OH) can bind gold colloids, yieldingAu/CD particles with an average hydrodynamic radius (RH) of 2 and 25 nm in water solution. The systemswere investigated by UV-vis, quasi-elastic light scattering, and FTIR-ATR techniques. The concentration ofamphiphiles was kept above the concentration of gold colloids to afford complete covering. In the case ofSC6NH2, basic conditions (Et3N, pH 11) yield promptly the decoration of Au, which can be stabilized bylinkage of CD amino and/or thioether groups. The critical aggregation concentration of SC6NH2 was measured(~4 
M) by surface tension measurements, pointing out that about 50% of CDs are present in nonaggregatedform. Whereas Au/SC6NH2 colloids were stable in size and morphology for at least one month, the size ofthe Au/SC6OH system increases remarkably, forming nanoaggregates of 20 and 80 nm in two hours. Underphysiological conditions, the gold/amino amphiphiles system can internalize in HeLa cells, as shown byextinction spectra registered on the immobilized cells. The gold delivered by cyclodextrins can inducephotothermal damage upon irradiation, doubling the cell mortality with respect to uncovered gold colloids.These findings can open useful perspectives to the application of these self-assembled systems in cancerphotothermal therapy.
M) by surface tension measurements, pointing out that about 50% of CDs are present in nonaggregatedform. Whereas Au/SC6NH2 colloids were stable in size and morphology for at least one month, the size ofthe Au/SC6OH system increases remarkably, forming nanoaggregates of 20 and 80 nm in two hours. Underphysiological conditions, the gold/amino amphiphiles system can internalize in HeLa cells, as shown byextinction spectra registered on the immobilized cells. The gold delivered by cyclodextrins can inducephotothermal damage upon irradiation, doubling the cell mortality with respect to uncovered gold colloids.These findings can open useful perspectives to the application of these self-assembled systems in cancerphotothermal therapy.