Dimethyl sulfoxide (DMSO)
diffusion in skin tissue
Marina D. Kozintseva, Alexey N. Bashkatov,
Elina A. Genina, Valery V. Tuchin
Department of Optics and Biophotonics
Saratov State University, Saratov, Russia
e-mail: a.n.bashkatov@mail.ru
marin15121991@mail.ru
Saratov Fall Meeting 2012
Motivation:
Saratov State University
Department of Optics and
Biophotonics
• The possibility of selective translucence of the superficial skin
layers is very useful in developing functional imaging and
therapeutic techniques. A potential benefit of the optical clearing is
the improvement of laser therapeutic techniques that enable
sufficient light penetration to a target embedded in tissue.
Combination of optical clearing with laser radiation can reduce the
laser fluences required for a therapeutic effect. However, in spite
of numerous investigations deal with transport of DMSO within
biological tissue the problem of estimating the diffusion
coefficient of the agent in skin has not been studied in details
• Goal of the study is to measure the diffusion
coefficient of DMSO in skin
Saratov Fall Meeting 2012
Materials and Methods
Saratov State University
Department of Optics and
Biophotonics
• For this study ten rat skin samples have been used. The
samples have been obtained from autopsy and kept in saline
during 24 hour until spectroscopic measurements at
temperature 4-5°C
• Measurement of collimated transmittance have been
performed using a commercially available spectrometer
USB4000-Vis-NIR (Ocean Optics, USA) in the spectral range
400-1000 nm. All measurements were performed at room
temperature (about 20°C)
• As a clearing agent DMSO solution was used. Refractive
index of the solution is 1.476. It has been measured using
Abbe refractometer at wavelength 589 nm
Saratov Fall Meeting 2012
Experimental setup
Saratov State University
Department of Optics and
Biophotonics
The scheme of experimental setup for the measurements of
collimated transmittance:
1.
2.
3.
4.
5.
6.
7.
8.
Halogen lamp (HL 2000)
Delivering optical fiber
Tissue sample
Glass cuvette with object
plate
Receiving optical fiber
Multichannel spectrometer
(USB4000-Vis-NIR)
PC
Collimators
Saratov Fall Meeting 2012
Method for determination of DMSO
diffusion coefficient
Saratov State University
Department of Optics and
Biophotonics
Determination of DMSO concentration within skin has been
performed using the assumption:
T ~ exp    s l 


2
 2 ax3 2
2
3


s  N
m  1 1 
1    1   


2
  m 2  1 
8


x  2 anI 
m  ns nI
nI  nI 0 1  C   ncC
• T is the collimated transmittance; µs is the scattering coefficient; l is the tissue
thickness; N is the numerical concentration of the tissue scatterers; a is the
scatterers radius; ns = 1.476 is the refractive index of the scatterers; nI is the
refractive index of interstitial fluid of the tissue; and  is the volume fraction of
the scatterers; nI0 = 1.332 is the refractive index of interstitial fluid of skin
before DMSO diffusion; nc is the refractive index of the DMSO solution; and C
is the concentration of DMSO within skin
Saratov Fall Meeting 2012
Method for determination of DMSO
diffusion coefficient

8
C  t   C0 1  2
 

Saratov State University
Department of Optics and
Biophotonics
2


2 
2
exp    2i  1 t
D l 

2
4
i  0  2i  1

 

1
• C (t) is the volume-averaged concentration of the
DMSO within tissue sample, g/ml; D is the diffusion
coefficient, cm2/sec
Saratov Fall Meeting 2012
Method for determination of DMSO
diffusion coefficient
Saratov State University
Department of Optics and
Biophotonics
C  t   C0 1  exp  t   
2
4l
 2
 D
D  pD0  1    D0
•  is the diffusion time constant, sec; p is the porosity
coefficient of skin;  is the volume fraction of
scatterers; and D0 is the DMSO diffusion coefficient
in interstitial fluid, cm2/sec
Saratov Fall Meeting 2012
Results: DMSO diffusion
0 sec
60 sec
200 sec
391 sec
1110 sec
2491 sec
4045 sec
0,14
collimated transmittance
0,12
0,10
Saratov State University
Department of Optics and
Biophotonics
The time-dependent transmittance of
the rat skin measured at different
wavelength concurrently with
administration of DMSO solution
0,08
0,06
0,04
0,02
0,00
500 nm
600 nm
700 nm
800 nm
900 nm
0,14
400
500
600
700
800
900
1000
0,12
The transmittance spectra of the rat
skin measured concurrently with
administration of DMSO solution at
different time intervals
collimated transmittance
wavelenght, nm
0,10
0,08
0,06
0,04
0,02
0,00
0
1000
2000
3000
4000
time, min
Saratov Fall Meeting 2012
Saratov State University
Department of Optics and
Biophotonics
Results: DMSO diffusion
coefficient
Sample
Thickness,
mm
Diffusion coefficient,
cm2/sec
Sample
Thickness,
mm
Diffusion coefficient,
cm2/sec
1
0,63
(3,990.21)10-6
6
0,88
(1,282.87)10-6
2
0,87
(9,980.68)10-6
7
1,33
(7,130.72)10-6
3
0,51
(7,132.24)10-7
8
0,41
(2,591.50)10-6
4
0,32
(1,891.78)10-6
9
0,87
(1,840.28)10-6
5
0,56
(7,940.63)10-6
10
0,47
(4,060.04)10-6
<D>=(4,783,045)x10-6 cm2/sec
Saratov Fall Meeting 2012
Acknowledgements
Saratov State University
Department of Optics and
Biophotonics
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-КО 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
Saratov Fall Meeting 2012