Multiple targeting in photoacoustic imaging using bioconjugated gold nanorods

Pai Chi Li, Chen Wei Wei, Chao Kang Liao, Cheng Dah Chen, Kuei Chen Pao, Churng Ren Chris Wang, Ya Na Wu, Dar Bin Shieh

Research output: Chapter in Book/Report/Conference proceedingConference contribution

24 Citations (Scopus)

Abstract

Cancer cells presented altered surface molecules to encourage their growth and metastasis. Expression of oncogeneic surface molecules also play important roles in the prediction of clinical outcome and treatment response of anti-cancer drugs. It is thus conceivable that imaging of cancer lesions while simultaneously obtaining their pathogenic information at molecular level of as many oncogenic proteins as possible is of great clinical significance. Gold nanoparticles have been used as a contrast agent for photoacoustic imaging. In addition, gold nanoparticles can be bioconjugated to probe certain molecular processes. An intriguing property of gold nanoparticles is its ability to tailor its optical properties. For example, size effects on the surface plasmon absorption of spherical gold nanoparticles have shown that the peak optical absorption red-shifts with the increasing particle size. In addition, the optical absorption spectrum of cylindrical gold nanoparticles (i.e., gold nanorods) exhibits a strong absorption band that is directly related to the aspect ratio. With these unique characteristics, selective targeting can be achieved in photoacoustic molecular imaging. Specifically, gold nanorods with different aspect ratios can be bioconjugated to different antibodies. Multiple targeting and simultaneous detection can then be achieved by using laser irradiation at the respective peak optical absorption wavelength. In this study, photoacoustic multiple targeting using gold nanorods is experimentally demonstrated. We have chosen Her2 and CXCR4 as our primary target molecule as Her2 expression is associated with growth characteristics and sensitivity to Herceptin chemotherapy. On the other hand, CXCR4 expression predict the organ-specific metastatic potential of the cancer cells for clinical intervention in advance. Monoclonal antibody (mAb) against Her2/neu was conjugated to nanorods with several different aspect ratios. The agarose gel is suitable for photoacoustic signal acquisition. A wavelength tunable Ti-Sapphire laser was used for laser irradiation and a 1 MHz ultrasound transducer was used for acoustic detection. The optical wavelength of the laser was tuned between 800 nm and 940 nm, corresponding to gold nanorods of an aspect ratio ranging from 3.7 to 5.9. The results clearly show the potential of photoacoustic molecular imaging with multiple targeting in revealing different oncogene expression levels of the cancer cells.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
DOIs
Publication statusPublished - 2006 May 8
Event7th Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics - Photons Plus Ultrasound: Imaging and Sensing 2006 - San Jose, CA, United States
Duration: 2006 Jan 222006 Jan 26

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume6086
ISSN (Print)0277-786X

Other

Other7th Conference on Biomedical Thermoacoustics, Optoacoustics, and Acousto-optics - Photons Plus Ultrasound: Imaging and Sensing 2006
CountryUnited States
CitySan Jose, CA
Period06-01-2206-01-26

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Multiple targeting in photoacoustic imaging using bioconjugated gold nanorods'. Together they form a unique fingerprint.

Cite this