Alexey N. Bashkatov, Georgy S. Terentyuk, Elina A. Genina,Daniil A. Chumakov, Artem G. Terentyuk, Vadim D. Genin, Valery V. Tuchin,
Saratov State UniversityAlla B. Bucharskaya, Galina N. Maslyakova, Nikita A. Navolokin,
Saratov State Medical UniversityBoris N. Khlebtsov, Nikolay G. Khlebtsov,
IBPPM RAS, Saratov, Russia
SFM'12September 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 nano-thermolysis, 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: 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: 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)
Laser (808 nm)
Thermocouple
Thermal imager
Hot bench
Rat
Tumor
0 2 4 6 8 10
30
35
40
45
50
55
60
T
em
pe
ratu
re, C
Time, min
Rat 1 Rat 2 Rat 3 Rat 4 (control)
Temporal dependence of the tumor temperature measured with the thermal imager
0 2 4 6 8 1020
24
28
32
36
40
44
48
52
Rat 1 Rat 2 Rat 3 Rat 4 (control)
Te
mp
era
ture
, C
Time, min
Temporal dependence of the tumor temperature measured with the thermocouple
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)
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
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