Anna I. Volkova

Application of aluminum phthalocyanine nanoparticles for fluorescent diagnostics in dentistry and skin autotransplantology

This paper deals with the possibility of application of aluminum phthalocyanine (AlPc) nanoparticles in clinical practice. AlPc fluoresces in the molecular form but in the form of nanoparticles it does not. Separation of molecules from an AlPc nanoparticle and therefore the appearance of fluorescence occurs under the effect of a number of biochemo-physical factors. Owing to this feature the application of AlPc nanoparticles followed by the measurement of fluorescence spectra is proposed as a diagnostics method. It was shown that after AlPc nanoparticle application on a tooth surface the fluorescence intensity in the enamel microdamage area is 2-3 times higher than that in the normal enamel area. The appearance of fluorescence after application of AlPc nanoparticles on skin autografts testifies to the presence of inflammation.

Noninvasive evaluation of absolute fluorochrom concentration in various tissues in vivo by means of standard samples with modeled optical properties

The problem of accurate determination of fluorochrome concentration in tissues from fluorescent spectra is the most important one in the spectroscopy of biological objects. Especially it is significant for the application of photodynamic therapy (PDT) when the concentration of photosensitizer (PS) in tumor and surrounding normal tissues should be known so that one could employ the appropriate treatment tactics (irradiation dose and time). It is also desirable that the screening depth be the same order as the light penetration depth used for treatment. To solve these problems we have prepared the standard samples with the optical properties close to that of tissues under investigation. The various fractions of sulphanated aluminum phtalocyanine (Al-Pc) have been used as photosensitizers. The samples with various concentration of Al-Pc have been prepared and the intensity of fluorescence excited by He-Ne laser, as well as the laser scattered line, have been measured to give a calibration curve.

Aluminium sulphophthalocyanine as an NIR photosensitizer for PDT

It was found that irradiation of aqueous solution of aluminum sulphophthalocyanine (SnPcAl) by light with wavelength of 805 nm in the presence of sodium ascorbate results in photodynamic type I effect. S2PcAl in adsorbed state on proteins or polysaccharide structures was shown to possess rather intense long wavelength absorption band in the NIR spectral region. The comparative tests of SnPcAl with sodium ascorbate on mice with Ehrlich carcinoma and leucosis P-388 showed that photodynamic efficiency in the case of NIR irradiation (790 nm) is not lower than using visible irradiation (675 nm).

Experimental study of PDT with aluminum sulphophthalocyanine using sodium ascorbate and hyperbaric oxygenation

It is well known that sulphophthalocyanine derivatives under laser irradiation induce photochemical reaction of II type with generation of cytotoxic agent - singlet oxygen. The combination of phthalocyanine and exogenic reductant - sodium ascorbate may also induce other reactions, involving the formation of free radicals, and thus intensify the antitumor effect. To improve the results of PDT we used the additional injection of sodium ascorbate, the hyperbaric oxygenation and different regimes of laser irradiation. We conducted the experimental study on 100 white mice with Erlich carcinoma. Macroscopic and microscopic data showed that sodium ascorbate significantly increases the effect of PDT in comparison with control group due to the higher tumor damage, vascular alterations, inhibition of cell proliferation and stimulation of antitumor desmoplastic reaction.

Improvement of cancer PDT using sulphophthalocyanine and sodium ascorbate

It is well known that sulphophthalocyanines induce in process of PDT photochemical reaction of II type with generation of cytotoxic agent -- singlet oxygen. The combination of phthalocyanine and exogenic reductant -- sodium ascorbate may also induce other reactions, involving the formation of free radicals, and thus intensify the antitumor effect. The mechanism of action of the ascorbate may be connected also with the direct tumor cells damage (apoptosis) and with the stimulation of antiblastome resistance. We conducted the experimental study on 150 white mice with Erlich carcinoma. Macroscopic and microscopic data showed that ascorbate significantly increases the effect of PDT in comparison with control group due to the higher tumor damage, inhibition of its growth and stimulation of antitumor desmoplastic reaction.

Phosphosubstituted phthalocyanine derivatives as effective photosensitizers for PDT

The photodynamic therapy in the spectral range 690 - 750 nm is more perspective for treatment of the deeply located tumors because the absorption of tissue has a significant minimis in this spectral range. A series of phosphosubstituted phthalocyanine derivatives were studied in vitro and in experiment on white mice. It has been shown that photodynamic therapy using these photosensitizers was very effective and induced the prominent tumor damage (necrosis, apoptosis), inhibition of its growth and stimulation of antitumor desmoplastic reaction.

Systemic estimation of the effect of photodynamic therapy of cancer

The effects of photodynamic therapy (PDT) of cancer needs objective estimation and its unification in experimental as well as in clinical studies. They must include not only macroscopical changes but also the complex of following morphological criteria: (1) the level of direct tumor damage (direct necrosis and apoptosis); (2) the level of indirect tumor damage (ischemic necrosis); (3) the signs of vascular alterations; (4) the local and systemic antiblastome resistance; (5) the proliferative activity and malignant potential of survival tumor tissue. We have performed different regimes PDT using phthalocyanine derivatives. The complex of morphological methods (Ki-67, p53, c-myc, bcl-2) was used. Obtained results showed the connection of the tilted morphological criteria with tumor regression.

New sensitizers and rapid monitoring of their photodynamic activity

At present, there are lots and lots of chemical compounds that are, to a certain extent, photodynamically active. Therefore, the task of carrying out the expressive screening of such compounds has been raised sharply enough. The primary screening in vitro of compounds, with the help of biological liquids, is notable for quickness and cheapness at the same time, it is possible to determine the comparative characteristics of compounds by their photodynamical activity. Decomposition of albumins of a mixture of photosensitizer and biological liquid when irradiating with light is the basis of this method. Efficiency of decomposition of components of biological liquids is determined using biochemical reactions (e.g., those for determining the total albumins or blood hemoglobin). Subsequently, with a sufficient efficiency of a photosensitizer, it will be possible to carry out a study in vivo, with the purpose of establishing accumulation of preparations in tumor.

Dynamics of the binding and change of photosensitizers of phthalocyanine row concentration in malignant tumors: experimental results

The results of investigations of photosensitizers distribution, accumulation and outputting in the process of photodynamic therapy on the model of Erlikh carcinoma in the experiment are adduced. Phthalocyanines of Al, differing in technology of synthesis and content of sulfa groups, have been used. The character of photosensitizer binding has been determined by the change of its spectral characteristics after binding with albumin in vitro and by analysis of fine structure of fluorescence spectra in vivo.

Cobalt Phthalocyanine Nanoparticles Capable Of Reversible Aggregating In Biotissues Under Physical Action

Investigation of the cobalt phthalocyanine transformation dynamics under the influence of laser irradiation and weak electric fields in vitro and in vivo. Development of electrochemical and optical methods of influence on tumor tissue containing cobalt phthalocyanine under spectroscopic and thermal control.