In this study we evaluate in vitro the cytotoxic activity of two newly synthesized phthalocyanines (metallo-complexes) with absorption bands in the red part of the spectrum: zinc-tri-sulphonated phthalocyanine (ZnS4Pc). Two permanent animal tumor cell lines are used in the experiments: LSR-SF(SR)-transplantable sarcoma in rat induced by Rous sarcoma virus strain Schmidt-Ruppin and LSCC-SF(Mc29)-transplantable chicken hepatoma induced by the myelocytomatosis virus Mc29. Irradiation has been performed with a laser diode emitting at 672 nm in a wide range of radiant exposure (2-100 J/cm2) and irradiance of 120 mW/cm2. The neutral red uptake cytotoxicity assay has been used to evaluate the effect of the photosensitizers on cell viability. The light dose-response curves and light exposures that ensure viability drop to 50% and 10% have been obtained for each cell line. The ability of the compounds to induce apoptosis has been determined by acridine orange dye staining.
The aim of the present work is to compare the photodynamic effect in vitro for permanent cell lines established from some of the most common and invasive human cancers (breast cancer and brain glioblastoma) as well as for animal cell lines obtained from virus-induced transplantable tumors. The cytotoxicity assessment was performed for human breast adenocarcinoma MCF-7, human glioblastoma 8-MG-BA, and two virus-induced animal tumor cell lines: a cell line LSCC-SF-Mc29, obtained from a transplantable chicken hepatoma induced by the myelocytomatosis virus Mc20, and a line LSR-SF-
SR, obtained from a transplantable sarcoma in rat induced by Rous sarcoma virus strain Schmidt-Ruppin. We used in the experiments a PS produced by NIOPIK (Russia) [www.tech-db.ru/istc/db/inst.nsf/wu] with peak absorption around 670 nm. The photodynamic effect was assessed by a neutral red uptake cytotoxicity test. To activate the photosensitizer we used a semiconductor laser that emitted at 672 nm at irradiance of 120 mW/cm2; the latter value had been chosen after comparison of the photodynamic effect at 12, 60 and 120 mW/cm2.
Observation of ultra-fast relaxation processes with time-constants below 1 ps in a wide spectral range can be made using a low-coherent light source, which is equivalent to a very short pulse in the non-linear correlation spectroscopy. The same approach can be used for very accurate and practically in real time determination of spectra of coherent and non-coherent light sources by recording and processing of their correlation functions. To check the proposed approach, we made a prototype of a correlation Fourier spectrometer based on a Michaelson interferometer and we developed a method for processing of the recorded interferograms which had been proved by a Monte-Carlo simulation. Different semiconductor light sources (LD, LED and high-power LED) were tested. The good quality of the obtained spectra was confirmed by comparison with OSA measurements (resolution 0.28 nm). The time required for data recording and spectrum restoration is within few seconds. This permits current tuning of the investigated sources, which extends their possible applications in spectroscopy, optical communications, computer technologies, etc.
The high temporal resolution and accuracy of spectrum restoration achieved with a correlation Fourier spectrometer substantially depend on the precise knowledge of the optical characteristics of the used operating white light source. However, the beforehand calibration of this source does not guarantee avoiding of errors due to random disturbances during spectrometer’s operation. In the present work we solved two tasks. We analyzed the noise sources in a three-channel Fourier spectrometer with simultaneous recording of interferograms for the etalon light source, for the operating source and for the investigated sample using Monte-Carlo simulations. As a second task we made a prototype of a correlation Fourier spectrometer and simulated the real-time tracking of changes in autocorrelation functions of different semiconductor light sources (LD, LED and high-power LED) using the measured interferograms. We proposed an analogous feedback system to perform a current correction of the autocorrelation of the operating light source following the changes in the autocorrelation function of the etalon source.