Transcript Presentation

Alexey N. Bashkatov, Georgy S. Terentyuk, Elina A. Genina,
Daniil A. Chumakov, Artem G. Terentyuk, Vadim D. Genin, Valery V. Tuchin,
Saratov State University
Alla B. Bucharskaya, Galina N. Maslyakova, Nikita A. Navolokin,
Saratov State Medical University
Boris N. Khlebtsov, Nikolay G. Khlebtsov,
IBPPM RAS, Saratov, Russia
SFM'12
September 25-28, 2012, Saratov, Russia
After pioneering works of early 1980s, there is
a significant and growing interest in
developing laser therapy methods for cancer
treatment
These methods are based on mechanisms of
selective damage of abnormal (target) cells in
the manner that is safe for surrounding
normal cells
These
methods
use
photochemical,
photomechanical, and photothermal effects
of laser interactions with cells and tissues
It was recently established that laser-induced local heating of
cellular structures (through photothermal (PT) mechanisms),
using either pulsed or continuous laser radiation and mediated
by light-absorbing nanoparticles and microparticles, may
provide precisely localized damage that can be limited to single
cells
Accumulation of light-absorbing nanoparticles in relatively
transparent cells may enhance their optical absorption up to
several orders of magnitude
Thus, nanoparticles (NP) act as localized sources of laser-induced
heat that can cause cell damage
Even greater potential for selective damage of target (e.g., cancer)
cells exists through integration of NPs allow specific targeting of
the cells
PT effects of continuous wave radiation (such as hyperthermia) are
most effectively used in damaging relatively large areas of
abnormal tissues
However, despite apparent advantages of the laser nanothermolysis, the full potential of this method has not been
realized yet
Nanocomposite:
Gold nanorods coated with
silicon dioxide layer with
hematoporphyrine molecules
(Au-SiO2-Hp) (l=108±12 nm,
d=75±6 nm)
Experimental Animals:
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Three white autbred rats with
transplanted liver tumor were
used
One rat served as a control
1 mL of the nanocomposite
was injected 1 hr before the
experiment by 0.2 mL every 1
min
The rats were anaesthetized
with Zoletil 50 (Virbac, France)
Irradiation:

Laser (LCS-T-12, Russia) with
irradiation wavelength 808 nm,
power 2 Wt, power density 2.3
Wt/cm2
Monitoring:
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Thermal imager (IRI4010,
IRISYS, UK)
Thermocouple K-TYPE, USA)
Histological study


Histilogical specimen were
taken from the sides of the
tumor after photothermolysis
Description of tumor tissue
specimen was made with
microscope МС 100 ХР (Micros,
Austria) integrated with camera
Canon РС 1107 (Canon Inc.,
Japan) in transmitted light
mode with magnification ×200
TEM-imaging of nanocomposite
Fluorescent spectra of
aqueous haematoporphyrin
solution (broken curve) and
nanocomposite suspension
(solid curve)
Thermal
imager
Tumor
Rat
Thermocouple
Hot bench
Laser (808 nm)
Temporal dependence of the tumor temperature measured with the
thermal imager
Temperature, C
60
55
50
45
Rat 1
Rat 2
Rat 3
Rat 4 (control)
40
35
30
0
2
4
6
Time, min
8
10
Temporal dependence of the tumor temperature measured with the
thermocouple
52
Temperature, C
48
44
40
36
32
Rat 1
Rat 2
Rat 3
Rat 4 (control)
28
24
20
0
2
4
6
Time, min
8
10
Liver cancer composed of lobules of various sizes which separated by
thin layers of connective tissue. Tumor cells were oval-round and had
eccentrically located nucleus. A significant part of the cytoplasm was
occupied by large vacuoles containing mucus
Necrosis are in 30-50% of tumor area
Tumor cells with degenerative
changes are preserved only in
the subcapsular zone, necrosis
are almost total (90-95% of
tumor area)
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It is shown that under action of laser irradiation
(808 nm) temperature of skin surface measured
with the thermal imager increases from
34.2±1.5°C up to 58.1±0.23°C for rats with the
tumors sensitized by the nanocomposite and up
to 48.8°C for the control rat
Temperature in the depth of the tumors
measured with the thermocouple increases from
31.5±2.1°C up to 43.5±2.1°C for the all rats. It
can be explained by inaccuracy of thermocouple
connection
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Grant #224014 Network of Excellence for
Biophotonics (PHOTONICS4LIFE) of the Seventh
Framework Programme of Commission of the
European Communities
Grants # 11-02-00560 and 12-02-92610-KO of
Russian Foundation of Basis Research
Russian Federation governmental contacts
02.740.11.0770, 02.740.11.0879, 11.519.11.2035,
and 14.B37.21.0728