الفهرس 
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Abstract
Photodynamic therapy (PDT) involves three individually non-toxic components that are combined to induce cellular and tissue effects. The first component of PDT is a photosensitiser, a photosensitive molecule that localizes preferentially in certain kinds of cells and/or tissues. The second component involves the administration of light of a specific wavelength. None of these factors is harmful by itself but in the presence of oxygen, the third and last required component, produce reactive oxygen species (ROS), cytotoxic agents that can inactivate tumor cells. Therefore, this treatment shows a dual selectivity that is produced by both a preferential uptake of the photosensitiser by the diseased tissue and its ability to confine activation of the photosensitiser by restricting the illumination to that specific area.
In the present work, a combined treatment of near infrared laser and Ultrasound waves with and without photosensitizer was investigated. Porphyrin derivative was used as a photosensitizer HPD and two sources of energy were used; namely infrared laser at three frequency levels (1000, 4000, and 7000 Hz) with power density 46.8 mW/cra2 and Ultrasound (pulsed and continuous wave mode) at power density 3 W/cm2 for 1 min.
Tumor bearing animals were divided into the following groups each of 7 mice
Two control groups, one untreated group and the other one was injected with the Hemato-porphyrin - dihydrochloride (12.5 mg/kg) only.
^ - Group consists of 21 mice was divided into 3 sub group and the site of the tumor wasft irradiated with IR laser at 1000, 4000 and 7000 Hz for one minute each.
Group consists of 21 mice injected IP with Hemato-porphyrin- dihydrochloride (12.5 mg/kg).This group was further divided into 3 subgroups, and the site of the tumor was irradiated with infrared laser at the same conditions of group 2.
Group consists of 14 mice divided into 2 subgroup and the site of the tumor was irradiated with ultrasound pulsed or continuous wave mode at 3 W/cm2 for one minute.
Group consists of 14 mice injected IP with Hemato-porphyrin -dihydrochloride (12.5 mg/kg). This group was further divided into 2 subgroups and the tumor site was irradiated with ultrasound at the same conditions of group 2.
One group consists of 10 mice injected IP with Hemato-porphyrin then exposed to infrared laser of 7000 Hz for one minute followed by exposure to continuous wave ultrasound at 3 W/cm2 for one minute.
Evaluation of the treatment effects.
• The length, the width and the height of the tumor were measured with a slide calliper every day before exposure to different*treatment modality and tumor volume was calculated.
• Tumor mass inhibition ratio and tumor volume growth ratio were calculated.
• Measurements of the dielectric properties of the tumor tissue at the end of treatment period to monitor the efficiency of the different treatment modality.
• Evaluation of the ultrastructural changes induced by different treatment modality in tumor tissue by transmission electron microscope.
The experimental results showed that:
«
• Treatment of Ehrlich Ascities tumor with photosensitizer alone has no or little effect on the tumor volume.
• The cytotoxic effect of IR laser photodynamic therapy increases with increasing of laser energy. Decreasing in the normalized tumor volume, tumor growth rate and inhibition ratio were observed either on using infrared laser alone with its three frequencies or in the presence of the HPD. However, the decline in the normalized tumor volume has minimum value at 7000 Hz infrared laser in the presence of the HPD.
• The cytotoxic effect of continuous wave ultrasound was more cytotoxic than that in pulsed wave. Similar variations occurred in case of using ultrasound exposure only or in the presence of the HPD, with minimum effect occurred on using ultrasound in the presence of the HPD.
• Combined treatment of IR laser at 7000 Hz and continuous wave ultrasound at
2 n
3W/cm in the presences of sensitizer was more cytotoxic and effective than IR laser and ultrasound alone.
• Relative permittivity of the tumor tissue decreased exponentially with increasing the applied frequency. Relative permittivity of treated tumor tissue with different treatment modalities decreased than that of untreated tumor.
• The real conductivity increased exponentially with increasing applied trequency for all the modes of treatments, while decreased in treated tumor than untreated tumor in the absence of the sensitizer but coincidence occurred in the presence of sensitizer.
• The variation of the imaginary permittivity with frequency showed sharp increase at low frequency followed by exponential decreased with all methods of treatments used.
• The ultrastructural changes reflected inertial Ultrastructural destruction to nuclear and cell organelles.
from the data of this work, we can conclude the following:
*
• Hemato-porphyrin -dihydrochloride is a potential photosensitizer and sonosensitizer for photodynamic or sonodynamic treatment of tumor tissue.
• IR laser combined with ultrasound in the presence of Hemato-porphyrin - dihydrochloride has a potential and obvious antitumor effect.
• Dielectric measurement gives information about electrical properties of the tumor tissue before and after the treatment and evaluates the efficacy of the treatment.
• Ultrastructure changes play important roles in inhibiting tumor growth and even inducing cell death, which might be attributed to Photo or sono-chemical activation mechanism.
• Combination of photodynamic therapy with sonodynamic therapy in the presences of sensitizer has a potential and obvious antitumor effect.