Dr. Rinat Ankri and Dr. Dror Fixler Gold Nanorods as Absorption Contrast Agents for Noninvasive Detection of Cancer and Arterial Vascular Disorders Dr. Rinat Ankri and Dr. Dror Fixler Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Israel

Light Interaction with a Turbid Medium Input Specular Reflection Diffuse Reflection Scattering Absorption Direct Transmission Diffuse Transmission

Light Path in Irradiated Tissues- The Diffusion Theory Where: m= ? Thus, the diffusion reflection (DR) intensity depends on µa and µs’: Where: ρ= light source-detector distance m = 1 or 2 Schmitt et al., 1990

The experimental set-up 250 µm per step 650 nm PD Output Digital Scope PD Input Optical fiber PD   The experimental set-up Sample Fiber Optic Detector 1mm 250 µm per step

The Diffusion Theory; m=1 Simulation Expected µs’=1.6 mm-1* Experiments Experimental µs’~2.8 mm-1 * Cubeddu et.al., 1993

The Diffusion Theory; m=2 Expected µs’=1.6 mm-1* * Cubeddu et.al., 1993 m= 2 ! Simulation Experimental µs’~1.5 mm-1 Experiments Ankri et.al, The Open Optics Journal, 2011

Diffusion Reflection and Gold Nano Particles

Structural Imaging Molecular Imaging

“Fantastic Voyage” Isaac Asimov (1966) The Vision

Why Gold?

TEM FAAS CT Subcellular Cellular Whole body

Hand with Ring (Wilhelm Röntgen,1895) The Concept Hand with Ring (Wilhelm Röntgen,1895)

GNP’s as blood contrast agents

Surface plasmon resonance When a nanoparticle is much smaller than the wave length of light, coherent oscillation of the conduction band electrons induced by interaction with an electromagnetic field. This resonance is called Surface Plasmon Resonance (SPR). Figure: Schematic of plasmon oscillation for a sphere, showing the displacement of the conduction electron charge cloud relative to the nuclei.

Optical Properties of Gold Nanorods Gold nanorods have shape and size-dependent optical properties originating from anisotropic shape and tunable aspect ratio. Nikoobakht et al. Chem Mater. 2003, 15, 1957-1962. Aspect Ratio (AR) = L/W L W

Gold Nanorods Under electromagnetic field of light, the conduction band electrons undergo a collective coherent oscillation in resonance with the frequency of the incident light. This is known as the localized surface plasmon resonance (LSPR). Due to their anisotropic shape, 2 extinction peaks can be observed from gold nanorods. Huang et al. Adv Mater. 2009, 21, 4880-4910.

A new method for cancer detection based on diffusion reflection measurements of targeted gold nanorods GNR (25 x 65 nm) UV-Vis absorption spectra (normalized) and TEM image

Head & Neck Cancer Cell Au

Tumor detection based on DR measurements of targeted gold nanorods (GNR) Enhancing the tumor absorption coefficient by EFGR labeled GNR injection. 650 nm Tumor µa 650 nm Diffusion Reflection measurements

Diffusion reflection decreases faster due to GNRs accumulation 6 -6 GNRs injection

Tumor detection based on DR of targeted gold nanorods (GNR) The tumor presents a slope different from the normal tissue’s slope even more than 20 hours post injection. Ankri et.al; A new method for cancer detection based on diffusion reflection measurements of targeted gold nanorods, International journal of Nanomedicine, 2012

Different absorption coefficients Expected µa (mm-1) Slope2 Experimental µa (mm-1) 0.0123 0.011±0.006 0.012±0.0007 0.0132 0.0143±0.003 0.0131±0.0031 0.0152 0.0256±0.003 0.0146±0.0007 0.0216 0.0625±0.004 0.0229±0.001 0.0312 0.137±0.0016 0.0397±0.0004 0.0986 0.42±0.001 0.104±0.0002 GNR exntinction coefficient 1 ml/mg*mm

a quantitative study, Journal of Biophotonics, 2012 Calculating tumor GNR concentration from the DR profile in-vivo FAA spectroscopy GNR conc. in tumor = Time (∆Slope)2 GNR concentration (mg/ml) Before GNR injection t=15 min post GNR injection ------------------ t= 5 h post GNR injection 0.0036 0.0096 t= 10 h post GNR injection 0.0275 0.015 EGFR- targeted Ankri et.al; In-vivo tumor detection using diffusion reflection measurements of targeted gold nanorods- a quantitative study, Journal of Biophotonics, 2012

DR measurements of high concentrations of GNR- a Red shift is observed Dark field Microscopy: GNR with different densities

a spectral broadening is observed λ0 ∆λ DR measurements of tumor bearing mice with different concentrations of targeted GNR- a spectral broadening is observed Ankri et.al; Intercoupling surface plasmon resonance and diffusion reflection measurements for real-time cancer detection, Journal of Biophotonics, 2012

NEJM Dec 2013 The Aim: To develop a new, easy to use, and non-invasive method at low cost, to locate atherosclerotic vascular disease at its early stages, particularly unstable plaques with ongoing inflammation prone to rupture

Stable vs. Unstable (vulnerable) Plaques Rich in macrophages, foam cells, inflammatory cells, thin fibrous cap Rich in extracellular matrix smooth muscle cells, thick cap

Macrophages before incubation with GNRs Macrophages+ GNRs 0.02 mg/ml Macrophages+ GNRs 0.2 mg/ml

Macrophages +/-GNRs Homogenous and GNRs

In Vivo ; Rat injury MODEL A cross-section of a rat balloon-injured carotid artery 2 weeks post-injury stained with hematoxylin and eosin (H&E) clearly depicts cellular-rich neointima development. Magnification is 100x for the large photomicrograph. A right carotid artery B left injured carotid artery

First in vivo DR measurements of atherosclerosis with GNR

3D CT Artery imaging