1. Recent Applications of Radiation in Biophysics
Review article
Submitted by:
Omar Desouky
Medical Biophysics Lab.
Radiation Physics Department
National Center for Radiation Research and Technology
Atomic Energy Authority (AEA)
2010

2. Biophysics Biophysics is the exploration of living nature processes
by means of physical instruments, and the explanation
of their results by physical and mathematical concepts
Radiation biophysics is a branch of this field which looks
specifically at the
relationship between living organisms and radiation

3. Radioactivity
It was observed that ionizing radiations were able to damage living tissues and to kill living cells

4. High LET
Low LET

5. O H e- X ray  ray P+ H+ OH- Ho OHo
The absorption of energy from ionizing radiation produces damage to molecules by direct and indirect actions.
For direct action, damage occurs as a result of ionization of atoms on key molecules in the biological system. This causes inactivation or functional alteration of the molecule. Indirect action involves the production of reactive free radicals whose toxic damage to the key molecule has a biological effect.
X ray
 ray

6. Dose
Probability
Dose
Severity 6

9. I. Radiation Techniques

11. Diagnostic
Techniques

16. The differential coherent
cross section given by

17. Synchrotron Radiation
Synchrotron radiation is a very powerful source for a very wide range of scientific and techniqual applications.
In particular the high intensity, natural collimation and continuous spectrum make possible the production of intense, tuneable, highly monchromatic beams of radiation which cannot be produced in any other way

21. A. Molecular and Cellular Characterization

22. X-ray scattering profiles of lyophilized blood
(Desouky et al 2001, Phys. Med. Biol –106 )

23. X-ray scattering profiles of lyophilized hemoglobin, globin and heme
(Desouky et al 2001, Phys. Med. Biol –106 )

24. X-ray scattering from DNA and lyophilized packed red blood cells
(Desouky et al 2001, Phys. Med. Biol –106 )

25. B. Identification of radiation effects

26. X-ray scattering from lyophilized
hemoglobin for the control and irradiated
sample

27. The scattering profiles of the investigated samples was found to be reproducible and characteristics.
Theses profiles show pronounced sensitivity towards induced variations in molecular structure caused by gamma radiation

28. C. Diagnosis of some diseases

29. 1. Characterization of beta thalassemia
Normal Hemoglobin
Thalassemic Hemoglobin

30. X-ray scattering from lyophilized hemoglobin of control
and patients with b-thalassemia
(Desouky O. S et al Nuclear Instruments and Methods in Physics Research A
– )

31. 2. Scattering profile of normal serum and hepatocellulat
carcinoma
(Elshemey W M and Desouky O S et al 2004 , Phys. Med. Biol. 48 N239–N246)

32. 3. Measuring of Bone Density
Osteoporosis: Gradual loss of bone tissue leading to reduction in bone strength and eventually fracture

33. Bone mineral density (BMD)
Bone mineral density (BMD) is commonly measured using dual energy X- ray absorptiometry (DEXA)
This method involves X-ray beam transmission through the region of interest resulting in a measure of both cortical and trabecular bone density.

34. Royle and Speller 1995 & 1999 used the technique of Quantitative X-ray diffraction analysis (QXDA) to demonstrate the Trabecular bone tissue.
It is clear that the x-ray scattering profile has the ability to focus on a particular region of trabecular bone and separate the response of the marrow tissue from that of the bone

35. Differentiation between the cortical bone and trabecular bone
Hydroxyapatite
peak
It is clear that the signature of the trabecular bone shows the presence of mineral and non-mineral component.
This information would enhance the diagnostic capability of the trabecular bone loss
Desouky, Egypt.J .Biophys.Biomed.Enging. Vol.8, No. 2, pp (2007)

36. Monitoring the radiation effects on bone tissue
Desouky, Egypt.J .Biophys.Biomed.Enging. Vol.8, No. 2, pp (2007)

37. 4. Tumor characterization
The most sensitive technique for the early detection of breast cancer X-ray mammography Transmission X-ray image (approximately 18 keV).
However, the technique suffers from low specificity

38. Kidane et al., 1999 measured the breast tissue scattering Properties using Energy dispersive X-ray diffraction system
The adipose tissue show higher degree of ordering compared to other tissue, and this related to the intermolecular spacing lipid molecule

39. Monte Carlo simulation of normal and pathological breast tissue
Cancer
FWHM (nm-1)
0.71 ± 0.05
1.09 ± 0.14
(I2/I1%)
55.70% ± 13.33%
126.25% ± 22.39%
Area under curve
1.60 ± 0.06
1.91 ± 0.09
Desouky et al 2009 studied the X-ray scattering profile of the breast tissue during the supervision of the M.Sc of the student Mostafa Fakry

40. Characterization of tumor breast tissue
Scattered radiation can provide a powerful tool to distinguish between normal and breast tissue
SAXS and WAXS of normal and tumor breast tissue
(Desouky et al 2008)

41. Application of Synchrotron XRF
Geraki K and Farqusion 2001, 2004 used the Synchrotron XRF to find the concentration of iron, copper, zinc and potassium in healthy and cancerous breast tissue samples and found a trend of elevated levels in the cancerous tissue.

42. The Synchrotron XRF microprobe
Al-Ebraheem A et al 2009 used The Synchrotron XRF microprobe to find the concentration Ca, Fe, Cu and Zn in healthy and cancerous breast tissue samples.
They found correlation between the location cancer cells clusters and the areas of high metal content of Zn, Fe, Cu and Ca .

44. Treatment

45. Contribution of Biophysics in planning radiation therapy scenarios
Evaluation the influence of different radiation types
Determination the radiation distribution dose
The knowledge of the biophysical properties of charged particles and photons is essential in understanding their action mechanisms.

46. Applications of heavy charged particles

47. Basic Biophysical Properties of Particle Beams
Photon beams are characterized by a build-up effect in the first centimeters followed by an exponential decrease in their dose deposition with depth.
charged particle beams deposited the energy at a certain penetration depth
forming a high-dose region at the end of the particle range, known as the
Bragg peak

48. The depth-dose profile (Bragg Curve) exhibits a flat plateau region and a distinct peak near the end of range of the particles.
High biological efficiency of charged particles, causing more damage in the tumor cells than other kinds of radiation
These favorable biophysical properties of carbon ions and protons permit a highly-precise dose localization for tumor therapy, with sparring of normal tissues beyond the Bragg peak

49. Ion Beam Therapy
The problems is that the accelerator necessary to produce charged particles is too large to be build in hospital environment
Small accelerators based on new technological innovations are required.

50. II. Evaluation of Radiation effects

52. Rheological properties

54. 1-2mm
5-6mm mm

56. Brookfield DV-III Cone plate rheometer
Because blood is a non-Newtonian suspension, its fluidity cannot be described by a single value of viscosity.
Rotational viscometer allow the measurement of viscosity over a range of shear rates, yielding a flow curve

57. Blood flow curves for control and irradiated groups
(up to 7 Gy)

58. Where F is the shear stress, F0 is the yield stress η the viscosity,
S shear rate and f is the flow index

59. Bingham
Power law

60. Effect of exposure to gamma radiation on whole body blood rheological properties
The increase in blood viscosity may result in tissue damage by slowing the circulation of blood, and thus reducing the supply of oxygen and nutrient to the tissue cells

61. AC electric properties of Biological Membrane Under the influence of electric field

62. Applying external AC electric field
The dielectric studies are based on quantifying the response of a cell membrane to an electric field applied to it

64. Cell Membrane

65. Membrane potential and the equivalent circuit model
of the cell membrane
The cell membrane can be modeled electrically as a capacitor and resistance between the inta and extra cellular electrolyte

66. includes
Depends on the dynamical ionic transport, so it is a measure of the permeability
Determine the amount of charge can be stored across membrane when cell exposed to electric field,
so it is a measure of the polarizability in the electric field

68. Effect of radiation on the dielectric properties of red blood cells
Relative permittivity and AC conductivity for control and irradiated groups
(Selim et al., 2008)

69. The observed decrease in conductivity reflects the
permeability damage of the cell membrane
While the decrease in the relative permittivity and
dielectric loss reflects the radiation–induced
damage in the membrane charges

70. III. Radiation Protection

71. Natural 87% Manmade 13% Air 51% Misc. 0.3% Fallout 0.4% Medical 12%
Radon & Thoron
Cosmic 10%
Food 12%
Terrestrial 14%
Natural 87%
Manmade 13%
Misc. 0.3%
Fallout 0.4%
Occupational 0.2%
Nuclear 0.1%
Medical 12%

72. Quantities and Units for Radiation

73. Basic radiation protection strategies
Justification
Optimization
Dose limitation
Time
Distance
Shielding

75. Dose
Severity
Dose
Probability

78. Alpha lipoic acid

79. Alpha lipoic acid against different oxidative stresses
The ability of α-lipoic acid to protect the hemoglobin against β-thalassemic disease oxidative damage and exposure to Gamma radiation (150 Gy) Desouky et al, 2008

80. Effect of lipoic acid on the oxidative stress of thalassemia
and gamma radiation

83. Alpha lipoic acid against different doses of gamma radiation

84. Alpha lipoic acid against different doses of gamma radiation
Changes in the EPR (S4) signal intensity for control, irradiated and irradiated
& α- lipoic acid of RBC.

85. Conclusion

86. Applications of radiation in biophysics cover
many fields
Radiation techniques are applied in diagnosis and treatment of many diseases.
Biophysical measurements are applied for the early monitoring the effects of radiation exposure as they reflect the missing detailed of the biochemical and biological processes on a molecular level.
Biophysical studies are involved in testing and developing radioprotective agents.

88. Thanks for attention