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"Cancer cell imaging and photothermal therapy in the near-infrared region by using gold nanorods," by Xiaohua Huang, Ivan H. El-Sayed, Wei Qian, and Mostafa A. El-Sayed, Journal of the American Chemical Society, 128(6): 2115-20, 15 February 2006.

[Authors affiliations: Georgia Institute of Technology, Atlanta; University of California, San Francisco]

Abstract: "Due to strong electric fields at the surface, the absorption and scattering of electromagnetic radiation by noble metal nanoparticles are strongly enhanced. These unique properties provide the potential of designing novel optically active reagents for simultaneous molecular imaging and photothermal cancer therapy. It is desirable to use agents that are active in the near-infrared (NIR) region of the radiation spectrum to minimize the light extinction by intrinsic chromophores in native tissue. Gold nanorods with suitable aspect ratios (length divided by width) can absorb and scatter strongly in the NIR region (650-900 nm). In the present work, we provide an in vitro demonstration of gold nanorods as novel contrast agents for both molecular imaging and photothermal cancer therapy. Nanorods are synthesized and conjugated to anti-epidermal  growth factor receptor (anti-EGFR) monoclonal antibodies and incubated in cell cultures with a nonmalignant epithelial cell line (HaCat) and two malignant oral epithelial cell lines (HOC 313 clone 8 and HSC 3). The anti-EGFR antibody-conjugated nanorods bind specifically to the surface of the malignant-type cells with a much higher affinity due to the overexpressed EGFR on the cytoplasmic membrane of the malignant cells. As a result of the strongly scattered red light from gold nanorods in dark field, observed using a laboratory microscope, the malignant cells are clearly visualized and diagnosed from the nonmalignant cells. It is found that, after exposure to continuous red laser at 800 nm, malignant cells require about half the laser energy to be photothermally destroyed than the nonmalignant cells. Thus, both efficient cancer cell diagnostics and selective photothermal therapy are realized at the same time."

This 2006 report from the Journal of the American Chemical Society was cited 29 times in current journal articles indexed by Thomson Scientific during September-October 2007. During that two-month period, only one other chemistry paper published in the last two years (excluding reviews) attracted a greater number of citations. Prior to the most recent bimonthly count, citations to the paper have accrued as follows:

July-August 2007: 10 citations
May-June 2007: 9
March-April 2007: 16
January-February 2007: 6
November-December 2006: 6
September-October 2006: 4
July-August 2006: 2
May-June 2006: 1
March-April 2006: 2

Total citations to date: 85

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