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:
J
 D 2 J  a J
t
1
D
3( a   s ')
Thus, the diffusion reflection (DR) intensity depends on µa and µs’:
 c1 
(  )   m  exp(c2  )
 
Where:
ρ= light source-detector distance
c2 
3s ' a
m = 1 or 2
Schmitt et al., 1990
The experimental set-up
Optical fiber
PD Input
650 nm
250 µm per step
PD
Fiber Optic
Detector
1mm
250 µm per step
Sample
PD Output
Digital Scope
The Diffusion Theory; m=1
ln(  m (  ))  c1  c2 
3s ' a
c2 
0.25
m=1
Simulated
slope= 8.2267
slope2
0.2
Simulation
Exprimental
0.15
slope = 8.6105
0.1
0
0.0137 mm-1
0.05
0.0182 mm-1
0.0227 mm-1
-0.5
0
ln( (( ))
0.01
-1
0.012
0.014
0.016
0.018
0.02
0.022
0.024
Absorption coefficient (mm-1)
Expected µs’=1.6 mm-1*
-1.5
-2
Experimental µs’~2.8 mm-1
Experiments
-2.5
1
2
2
4
 (mm)
5
6
* Cubeddu et.al., 1993
The Diffusion Theory; m=2
Expected µs’=1.6 mm-1*
* Cubeddu et.al., 1993
0.1
m=2
Slope = 4.7533
Simulated
Exprimental
Slope2
Slope = 4.4467
Simulation
0.05
0.4
0.0182 mm-1
0.0137 mm-1
0.3
0.0227 mm-1
0
0.2
0.01
0.014
0.016
0.018
absorption coefficient
0.1
ln( 2(( ))
0.012
0.02
0.022
0.024
(mm-1)
0
-0.1
-0.2
-0.3
-0.4
Experimental µs’~1.5 mm-1
Experiments
1
2
3
4
 (mm)
5
6
Ankri et.al, The Open Optics Journal, 2011
“Fantastic Voyage” Isaac Asimov (1966)
TEM
Subcellular
FAAS
CT
Cellular
Whole
body
Hand with Ring (Wilhelm Röntgen,1895)
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.
Gold nanorods have shape and size-dependent optical properties
originating from anisotropic shape and tunable aspect ratio.
W
L
Aspect Ratio (AR) = L/W
Nikoobakht et al. Chem Mater. 2003, 15, 1957-1962.
15
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.
16
Normalized Intensity (A.U)
100
80
60
40
20
0
400
500
600
700
Wavelength [nm]
800
900
GNR (25 x 65 nm) UV-Vis absorption
spectra (normalized) and TEM image
Au
Au
650 nm
1.1
Enhancing the tumor absorption
Bare GNR
1
0.9
PEG coated GNR
coefficient by EFGR labeled GNR
0.8
Anti-EGFR coated GNR
0.7
injection.
0.6
0.5
0.4
0.3
400
500
600
700
800
Wavelength (nm)
Diffusion Reflection measurements
1
650 nm
Tumor µ a
Slope of ln(Г(ρ))
Normalized absorption (a.u.)
Tumor detection based on DR measurements of targeted gold nanorods (GNR)
Cancerous
Normal
0.5
0
Before
t =10 h
Time [hours]
Diffusion reflection decreases faster due to GNRs accumulation
6
6
-6
6
-6
6
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.
0
1.2
Normal before injection
Tumor before injection
-0.5
Normal, t=10 h
1
Cancerous
Normal
Tumor, t=10 h
Slope of ln(Γ(ρ))
ln(())
0.8
-1.5
-2.5
0.6
0.4
0.2
0
Before
-3.5
1
2
3
 (mm)
4
5
t=0
Time [hours]
t >10 h
6
Ankri et.al; A new method for cancer detection based on diffusion reflection measurements of targeted gold nanorods, International
journal of Nanomedicine, 2012
ln(  2 (  ))  3 a  s '
 s '(GNR )  0
c2 
Absorption (O.D)
1
Expected
µa (mm-1)
3s ' a
Different absorption coefficients
Slope2
Experimental µa (mm-1)
GNR exntinction coefficient
0.8
1 ml/mg*mm
0.6
0.4
0.2
0
0
0.02
0.04
0.06
GNR concentration (mg/ml)
0.08
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
Calculating tumor GNR concentration from the DR profile in-vivo
1.4
Tumor before
t = 15 min
t=5 h
t=10 h
1.2
FAA spectroscopy
GNR conc. in tumor
ln(2(())
1
0.8
slopes= GNR concentration
=
0.6
0.4
0.2
0
1
2
3
4
5
6
 (mm)
(∆Slope)2
GNR concentration (mg/ml)
Before GNR injection
0
0
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
Time
EGFR- targeted
Ankri et.al; In-vivo tumor detection using diffusion reflection measurements of targeted gold nanorodsa quantitative study, Journal of Biophotonics, 2012
DR measurements of high concentrations of GNRa Red shift is observed
Dark field Microscopy:
GNR with different densities
Normalized absorption (a.u)
1.2
1
0.8
0.6
0.4
0.2
0
450
1.6
1.4
550
650
750
Wavelength (nm)
650 nm
780 nm
1.2
∆Slope
1
0.8
0.6
0.4
0.2
0
0.01
0.02
0.05
0.1
Concentration (mg/ml)
0.15
0.2
850
1.2
λ0
DR measurements of tumor bearing mice with different
Absorption (a.u)
concentrations of targeted GNR-
a spectral broadening is observed
∆λ
1
0.8
0.6
0.4
0.2
0
450
550
650
750
850
Wavelength (nm)
 (mm)
1
2
3
4
5
6
0
-0.5
-1
-1
-2
ln(())
ln(())
0
 (mm)
-1.5
-2
-2.5
-3
1
2
3
4
5
-3
-4
Before, 650 nm
Before,780 nm
t>10,650 nm
t>10, 780 nm
-5
Before, 650 nm
Before, 780 nm
t>10 h, 650 nm
t>10 h, 780 nm
-6
Ankri et.al; Intercoupling surface plasmon resonance and diffusion reflection measurements for real-time cancer detection, Journal of
Biophotonics, 2012
6
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
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
20
Reflection (a.u)
18
16
14
12
10
450
500
550
Wavelength (nm)
600
650
Macrophages+ GNRs 0.2 mg/ml
Homogenous and GNRs
Normalized reflectance intensity (a.u)
1.5
1
0.5
0
1
1.5
2
2.5
3
3.5
4
4.5
-0.5
-1
-1.5
-2
Source-detector seperation (mm)
0.7
Macrophages +/-GNRs
Slope of DR profile
0.6
0.5
0.4
0.3
0.2
0.1
0
Phantom+GNRs
Phantom no GNRs
Phantom+
macrophages+GNRs
Phantom+
macrophages
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
0.2
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Before GNR
injection
24h post GNR
injection
Control