Measurement of optical properties of skin is an expanding and growing field of research. Recent studies have shown that the biological tissue, especially skin, changes the polarization state of the incident light. Using this property will enable the study of abnormalities and diseases that alter not only the light intensity but also its polarization state. In this paper we report an experimental study for measuring changes of polarization state of the light scattered from a phantom similar to a sample model of scattering skin. Using the notation of Stokes vector for the polarized light and Mueller matrix for the sample with its polarization properties, we have shown that some elements of the matrix were particularly sensitive to the changes of the polarization-altering physical properties of the scatterers within the phantom.

The results have shown that the new bioinformatic tool can be used in combination with the high-throughput proteomic data such as SELDI-TOF MS to find the potential biomarkers with high discriminative power.

This study aims to compare the continuous irradiation with fractionated irradiation for photodynamic therapy (PDT) of solid tumors with intraperitoneally administered 5-aminolaevulinic acid (ALA). Therefore, considering the complex physiology of solid tumors and in order to inform simulations well, we did experiments on Balb/c mice using non-invasive fluorescence spectroscopy to have a feedback of protoporphyrin IX (PpIX) concentration in tumor just before irradiation and during treatment. PDT simulations were performed based on delivery of 36 J cm(-2) total laser energy (630 nm) at the fluence rate of 40 mW cm(-2) either for continuous or fractionated illumination. Based on the calculated amounts of (1)O(2) dose deposition and comparing these amounts with the 5 × 10 (18) molecules cm(-3) threshold of reacting (1)O(2), simulation results demonstrate that fractionated illumination with alternating light and dark periods of 60 s improved the tumor response further for PpIX-mediated PDT.

Predicting the therapeutic outcome of photodynamic therapy (PDT) requires knowledge of the changes in photosensitizer concentration during the treatment. To investigate this, in vitro experiments were performed in which CT26 cells derivated from colon carcinoma tumor of BALB/c mice were injected subcutaneously in the right flank of mice. 5-aminolaevulinic acid is injected intraperitoneally at a dose of 500 mg kg -1 , and the fluorescence intensity in each tissue sample excised from tumor was measured with a spectrofluorometer at 2 and 3 hour after administration. Maximum fluorescence intensity of the tissue homogenates was detected at 600 nm. Results yield the possibility to determine the variation of induced PpIX in tumor by measuring fluorescence intensity and based on standard curve, which is useful for dosimetry in photodynamic therapy.