In vitro and In vivo studies on enhanced effects of electrical pulses in photodynamic therapy with 5ALA

Photodynamic therapy with 5-Aminolaevulinic acid (5ALA) is believed to be useful in treating the superficial or accessible malignant tumors. Nevertheless, several problems exist in using this photo sensitizer due to its side effects and the uncertainty in its location inside the target cells. The Treatment efficacy can be provided a improved lower dose of the dye can be used while coming up with a better way of determining its ldation. To achieve these aims, electrical pulses were utilized to facilitate 5 ALA entry into the cells. Materials and Methods: This research was carried out on W ehi-164 fibrosarcoma cell line and its subcutaneous tumors of Balb/c mouse (in vitro and in vivo). photodynamic treatments using 5ALA were designed on different groups, in the presence and absence of electrical pulses. Electrical doses were applied using a pulse square electroporator prior to the cell incubation with 5ALA and just 10 minutes after its intratumoral injection. Afterwards, illumination was applied by a non-coherent light source in the wavelength peak of 630 nm. The cell survival rate was determined for in vitro assessments by MTT test. For the in vivo studies, the tumor volume was calculated and the histopathologic examination was performed. Results: Based on the vitro data presented, the least cell survival has been obtained for 1 m M concentration of 5ALA with 900 V/cm pulses in higher illumination doses. At 0.2 m M ALA and higher illumination dose with electrical pulses, the cell survival has presented a significant difference in comparison to the similar group without pulse. On the basis of the histopathological experiments, necrosis is induced around the injection site of the dye in the tumor models in the completely treated tumors. The regressive percent of tumors in the control group, the group receiving only electrical pulses, the one receiving photodynamic without any pulse and the group receiving photodynamic with pulses was 1.7,2.6,42.0 and 82.2, respectively. Discussion and Conclusions: It seems that the efficacy of photodynamic treatments can be improved by applying electrical pulses at the beginning of cell incubation in the presence of a low concentration dye. Utilizing electrical doses with photodynamic therapy also damages the tumor. It is predicted that the obtained result is caused by the increased 5ALA concentration in the permeated cells following the application of pulses. Therefor, an improved tumor response can be achieved with a lower dose of photo sensitizer in these synergistic cures, while reducing the side effects of the dyes