Method and system for background suppression in magneto-motive photoacoustic imaging of magnetic contrast agents
Patent Number: US8701471
Executive Summary:
General Description:
Photoacoustics (PA) is very attractive for molecular imaging, because optical absorption is an efficient way to detect and differentiate specific molecules from other components. Molecular contrast agents are coupled to biological objects, such as cancer cells. When visualization of targeted molecules is necessary in the blood vessels, PA imaging is severely challenged by the large optical absorption of hemoglobin. A need exists to provide a method and device for suppressing background signal in magneto-motive photoacoustic imaging of magnetic contrast agents in complex systems.
The present invention provides a method and system for magneto-motive photoacoustic (mmPA) imaging that utilizes nanoparticles with combined strong magnetic and efficient optical absorption properties. The method and system provide for magneto-motive manipulation to differentiate a coupled contrast agent from background signals: the absorbent particles are collected in one area by a magnetic field, imaged, relocated to a different area by moving the magnet, and imaged again. Comparison of images from two locations allows for the background subtraction and increases the signal-to-noise ratio.
Scientific Progress:
The nanoparticles were observed in vivo in a mouse injected with the cancer cells labeled with the nanoparticles (ref. 1). Cancer cells were also detected ex vivo in flow tubes (refs 2 and 3).
Future Directions:
Strengths:
Patent Status:
Publications:
1: Li J, Arnal B, Wei CW, Shang J, Nguyen TM, O'Donnell M, Gao X. Magneto-optical nanoparticles for cyclic magnetomotive photoacoustic imaging. ACS Nano. 2015 Feb 24;9(2):1964-76. doi: 10.1021/nn5069258. Epub 2015 Feb 6. PubMed PMID: 25658655; PubMed Central PMCID: PMC4610822.
2: O'Donnell M, Wei CW, Xia J, Pelivanov I, Jia C, Huang SW, Hu X, Gao X. Can molecular imaging enable personalized diagnostics? An example using magnetomotive photoacoustic imaging. Ann Biomed Eng. 2013 Nov;41(11):2237-47. doi: 10.1007/s10439-013-0901-8. Epub 2013 Aug 27. Review. PubMed PMID: 23982280; PubMed Central PMCID: PMC3855400.
3: Wei CW, Xia J, Pelivanov I, Jia C, Huang SW, Hu X, Gao X, O'Donnell M. Magnetomotive photoacoustic imaging: in vitro studies of magnetic trapping with simultaneous photoacoustic detection of rare circulating tumor cells. J Biophotonics. 2013 Jun;6(6-7):513-22. doi: 10.1002/jbio.201200221. Epub 2013 Feb 18. PubMed PMID: 23420803; PubMed Central PMCID: PMC3705769.
Inventor Bio: Matthew O’Donnell
https://www.engr.washington.edu/sites/default/files/about/dean/odonnell_bio.pdf
Executive Summary:
- Invention Type: Diagnostic and Device
- Patent Status: US grant
- Patent Link: https://patents.google.com/patent/US8701471/
- Research Institute: University of Washington
- Disease Focus: Cancer
- Basis of Invention: Detection of cancer cells in the bloodstream
- How it works: Magnetic nanoparticles with high optical absorption properties are coupled to cancer cells. Each nanoparticle is detected in in the bloodstream at two separate spatial locations, which strongly reduces the background
- Lead Challenge Inventor: Matthew O'Donnell
- Inventors: Matthew O'Donnell, Xiaohu Gao
- Development Stage: Validated in a model system in vitro
- Novelty:
- Reduction of image background without a need of expensive two-dye labeling
- Clinical Applications:
- Early diagnostics of metastatic cancer
General Description:
Photoacoustics (PA) is very attractive for molecular imaging, because optical absorption is an efficient way to detect and differentiate specific molecules from other components. Molecular contrast agents are coupled to biological objects, such as cancer cells. When visualization of targeted molecules is necessary in the blood vessels, PA imaging is severely challenged by the large optical absorption of hemoglobin. A need exists to provide a method and device for suppressing background signal in magneto-motive photoacoustic imaging of magnetic contrast agents in complex systems.
The present invention provides a method and system for magneto-motive photoacoustic (mmPA) imaging that utilizes nanoparticles with combined strong magnetic and efficient optical absorption properties. The method and system provide for magneto-motive manipulation to differentiate a coupled contrast agent from background signals: the absorbent particles are collected in one area by a magnetic field, imaged, relocated to a different area by moving the magnet, and imaged again. Comparison of images from two locations allows for the background subtraction and increases the signal-to-noise ratio.
Scientific Progress:
The nanoparticles were observed in vivo in a mouse injected with the cancer cells labeled with the nanoparticles (ref. 1). Cancer cells were also detected ex vivo in flow tubes (refs 2 and 3).
Future Directions:
- Detection of cancer cells in bloodstream in vivo
Strengths:
- Very sensitive. Opens new possibilities in detection of abnormal cells, antigens, and other cancer biomarkers in the bloodstream.
Patent Status:
- Priority date: 2009-07-08
- Filed: 2011-10-13
- Published and granted: 2014-04-22
Publications:
1: Li J, Arnal B, Wei CW, Shang J, Nguyen TM, O'Donnell M, Gao X. Magneto-optical nanoparticles for cyclic magnetomotive photoacoustic imaging. ACS Nano. 2015 Feb 24;9(2):1964-76. doi: 10.1021/nn5069258. Epub 2015 Feb 6. PubMed PMID: 25658655; PubMed Central PMCID: PMC4610822.
2: O'Donnell M, Wei CW, Xia J, Pelivanov I, Jia C, Huang SW, Hu X, Gao X. Can molecular imaging enable personalized diagnostics? An example using magnetomotive photoacoustic imaging. Ann Biomed Eng. 2013 Nov;41(11):2237-47. doi: 10.1007/s10439-013-0901-8. Epub 2013 Aug 27. Review. PubMed PMID: 23982280; PubMed Central PMCID: PMC3855400.
3: Wei CW, Xia J, Pelivanov I, Jia C, Huang SW, Hu X, Gao X, O'Donnell M. Magnetomotive photoacoustic imaging: in vitro studies of magnetic trapping with simultaneous photoacoustic detection of rare circulating tumor cells. J Biophotonics. 2013 Jun;6(6-7):513-22. doi: 10.1002/jbio.201200221. Epub 2013 Feb 18. PubMed PMID: 23420803; PubMed Central PMCID: PMC3705769.
Inventor Bio: Matthew O’Donnell
https://www.engr.washington.edu/sites/default/files/about/dean/odonnell_bio.pdf