Study of photoinduced antitumor activity of phthalocyanin-based nanostructures as pro-photosensitizers in photodynamic therapy of malignant tumors in vivo.

Nanoparticles of aluminum and zinc phthalocyanin and metal-free phthalocyanin (AlPc, ZnPc, and H2Pc), whose molecular forms are photosensitizers, can serve as effective "prophotosensitizers" in photodynamic therapy for malignant tumors. Transition (stimulation) of photo-inert nanoparticles into a photoactive photosensitizer is realized locally in the tumor node by its exposure to potent laser pulses. Systemic injection of AlPc, ZnPc, and H2Pc nanoparticles has not led to accumulation of their photoactive form in the skin, which can lead to the development of skin phototoxicity. Effective protocols of photodynamic therapy with ZnPc nanoparticles are determined. The use of these protocols in mice with S-37 sarcoma led to 92-70% tumor growth inhibition, 48% improvement of survival, and cure in 84% cases.

[Intraoperative combined spectroscopy (optical biopsy) of cerebral gliomas]. / Intraoperatsionnaia kombinirovannaia spektroskopiia (opti-cheskaia biopsiia) gliom golovnogo mozga.

Clinical studies have revealed high selectivity of 5-ALA-induced protoporphyrin IX accumulation in different brain tumors. Modern methods of evaluation of tissues visible fluorescence are based on the qualitative analysis of the images. Up-to-date methods of combined spectral analysis allow fulfilling the intraoperative quantitative evaluation of the protoporphyrin IX content, as well as the scattering and absorption properties of a tissue. This paper presents a new method of the simultaneous analysis of hemoglobin concentration in oxygenated and reduced forms, tumor marker concentration (5-ALA-induced PP IX) and a new way to analyze the changes in the scattering properties of the tissues. The method is implemented by splitting the visible spectrum into intervals where hemoglobin and protoporphyrin IX have the characteristic peaks of absorption and fluorescence. The present method shows the dependence of the fluorescence index from the tumor grade. Combined spectroscopy (optical biopsy) can detect the differences between the subtypes of gliomas that are similar in the protoporphyrin IX fluorescence index. This method complements and enhances the diagnostic capabilities of spectroscopy, which is particularly important in the non-fluorescent glioma surgery.

[Intraoperative fluorescent visualization and laser spectrosopy in intrinsic brain tumor surgery].

Absence of well-defined borders of the glial tumor due to their infiltrative growth is one of the main issues in neurosurgery. A number of methods for intraoperative visualization are available today. The fluorescent metabolic navigation with 5-aminolevulinic acid (5-ALA) combined with quantitative laser spectroscopy is one of the latest technique. In our series of 99 consecutive patients with brain gliomas (WHO Grade I-IV) we found that visible fluorescence was observed in 68% of cases. Additional use of the laser spectroscopy could increase method sensitivity up to 74% due to accumulation of the protoporphyrine IX in nonfluorescense tumors. It was shown that there are some differences in quantitative fluorescence not only within same tumor (glioblastoma) but also in-between low- and high-grade gliomas. Intraoperative fluorescence and laser spectroscopy are effective and very helpful methods of intraoperative imaging in of intrinsic brain tumor surgery.

[Estimation of efficacy use of the dietary therapy in patients with type 2 diabetes with supplemented biologically active addition containing the extract of kurilsky tea].

It was investigated the influence of a diet with supplemented biologically active addition containing the extract of kurilsky tea on dynamics of the clinical and metabolic parameters in type 2 diabetes. It was shown that the inclusion of biologically active addition "Extralife" in dietary treatment of type 2 diabetes allows to decrease the hyperlipidemia and to improve the antioxidative state and thus to decrease the risk of vascular complications in this disease.

[Experimental rationale for a transscleral approach to thermotherapy for intraocular tumors, by using a photosensitizer].

The authors present the results of an experimental study of the pattern of distribution of laser radiation at a wavelength of 810 nm in the normal and Photosens-photosensitized eye tissues and analyze the distribution of a temperature at the sclera/choroidea/ tumor border during transscleral radiation delivery. To further the goal, the authors have resorted to computer mathematical simulation. In convergent-beam radiation supply, the proportion of a scattered radiation component has been ascertained to be lower in the surface scleral layer than that in the layers adjacent to the choroidea and the base of a tumor. On entering the sclera, a splash of light decreases and power density and radiation-induced heating of the deeply located tissues increase. Thus, the major hyperthermic effects show themselves in the tumor rather than on the sclera.

[Analysis of changes in the accumulation of the photosensitizer Photosens, its elimination kinetics and distribution in the tissues of the eye and eyelids in health and in some tumorous processes].

The authors analyze and present the results of spectroscopic studies into changes in the accumulation of the photosensitizer Photosens, its elimination kinetics and distribution in the tissues of the eye and eyelids, as well as in the tumors that have developed at these sites. The findings allowed the authors to estimate the duration of the agent's persistence in the eye tissues and the time interval associated with the high risk for phototoxic eyelid skin and conjunctival reactions and to determine a possibility of and conditions for photodynamic therapy, as well as the length of hospital stay when the latter was performed.

Photodynamic therapy of virus-associated precancer and early stages cancer of cervix uteri.

We have analyzed the results of photodynamic therapy using light-sensitizing agent "Photogem" in 72 patients - 56 women with pre-cancerous lesions of cervix and 16 women with early cervical cancer (group 1); Photosens in 47 patients - 35 women with pre-cancerous lesions (CIN III), 12 women with non-invasive cervical cancer (carcinoma in situ) (group 2); and Alasens in 22 patients - 8 women with virus-associated pre-cancerous lesions (high-grade CIN III), 14 with virus-associated early cervical cancer (carcinoma in situ, cervical cancer 1A1) (group 3). The results were as follows: group 1 - complete regression of CIN III and non-invasive cervical cancer (carcinoma in situ) was achieved in 50 (89.2%) and 11 (68.8%) cases, significant regression was achieved in 2 cases (3.6%) and in 2 cases (12.5%), stabilization was achieved in 2 cases (3.6%) and in 2 cases (12.5%), progression was achieved in 2 cases (3.6%) and in 1 case (6.2%) accordingly. In the group of patients after PDT using Photosens complete regression of CIN III and non-invasive cervical cancer (carcinoma in situ) was achieved in 33 cases (94.2%) and in 10 cases (83.4%) cases, significant regression was achieved in 1 case (2.9%) and in 1 case (8.3%), stabilization was achieved in 1 cases (2.9%) and in 1 cases (8.3%). In the group of women after surgical treatment anti-viral efficacy was assessed. It s necessary to note that not a single relapse was observed. Anti-viral effect was registered in 49 (90.4%) cases The longest HPV-free period that we observed was 5 years. 12 women with CIN III and 4 women with carcinoma in situ became pregnant.

[Feasibilities of photodynamic therapy in the treatment of corneal mycotic lesions: an experimental study].

The paper presents the results of studying the photofungicidal activity of a photosens (octacationic phthalocyanine) in the in vitro and in vivo systems. Cultured Candida guilliermondii were employed in in vitro investigations. The single combined action of octacationic phthalocyanine at a concentration of up to 1 microM and laser irradiation at a wavelength of 675 nm were established to allow the high activation (up to 100%) of yeast fungi to be achieved in the in vitro system. In vivo investigations were performed on 14 rabbits (28 eyes) with induced keratomycosis. In the first series, fluorescent diagnosis of photosens accumulation in the pathological corneal areas was made in 9 (18 eyes). Based on the data obtained in the second series of experiments, the authors examined the feasibilities of photodynamic therapy for corneal mycotic lesions with the above photosensitizer in 5 rabbits (10 eyes).

[Polyelectrolyte microcapsules as systems for delivery of biologically active substances].

Novel biodegradable microcapsules for delivery of biologically active substances (BAS) were prepared by layer-by-layer (LbL) adsorption of oppositely charged polyelectrolytes, namely sodium alginate (Alg) and poly-L-lysine (PLL). To immobilize these BAS, porous spherical CaCO3 microparticles were used as templates. The templates (cores) were coated with several layers of oppositely charged polyelectrolytes forming shell on a core surface. The core-shell microparticles were converted into hollow microcapsules by a core dissolution after an EDTA treatment. Mild conditions for microcapsule fabrication allow to perform an entrapment of various biomolecules while keeping their bioactivity. Biocompatibility and biodegradable capability of the polyelectrolytes give a possibility to use the microcapsules as the target delivery systems. Chymotrypsin (Chym) entrapped into the microcapsules was used as a model enzyme. The immobilized enzyme was found to keep about 86% of the activity compared to a native Chym. The obtained microcapsules were stable at an acidic medium while they could be easily decomposed by trypsin treatment at an slightly alkaline medium. Chym was shown to be active after being released from the microcapsules decomposed by trypsin treatment. Thus, the microcapsules prepared by the LbL - technique can be used for the development of new type of BAS delivery systems in humans and animals.

[Photodynamic therapy in treatment of chorioid neovascularization].

The authors studied the effectiveness of photodynamic therapy (PDT) with Photosence, a Russian photosensitizer, in treatment of chorioid neovascularization (CNV) in cases of age-related macular degeneration (ARMD) and pathological myopia (PM). The subjects were 73 patients with CNV suffering from ARMD and PM. The efficiency of PDT and complex conservative therapy was compared using vision acuity measurement, retinal morphometry, and fluorescent eye ground angiography (FEGA), performed before treatment, immediately after treatment, and 1, 3, 6, and 12 months later. The study showed that PDT in patients with CNV, ARMD and PM was more efficient than pharmacotherapy. Vision acuity improved or stabilized, and the parameters of retinal morphometry and FEGA improved as well. The results of the study evidence high efficiency of PDT with Photosence in treatment of CNV with ARMD and PM.

[Entrapment of herbal extracts in biodegradable microcapsules].

The microcapsules with entrapped herbal water-soluble extracts Plantago major and Calendula officinalis L. (HE) were prepared by LbL-adsorption of carrageenan and modificated chitosan onto CaCO3 microparticles with their subsequent dissolving after the treatment of EDTA. Entrapment of HE was performed by adsorption and co-precipitation techniques. The co-precipitation provided better entrapment of HE compared to adsorption. In vitro release kinetics in an artificial gastric juice (AGJ) was studied. The HE release was shown to accelerate gastric ulcer treatment in a rat model.

[Photodynamic therapy for subretinal neovascular membranes. Communication 2. Results of treatment for complicated myopia].

The efficiency of photodynamic therapy (PDT) versus drug therapy was evaluated in patients with subretinal neovascular membranes (SNM) in complicated myopia (CM). Photosens (aluminum phthalocyanine) was intravenously injected in a dose of 0.05 mg/kg. The irradiation conditions were as follows: a session was carried out, using a laser at a wavelength of 675 nm, in an exposure light dose of 120 J/cm2. The number of sessions ranged from 3 to 5 a week, depending on the clinical picture of SNM. The total light dose was not greater than 500 J/cm2. Twelve months after drug therapy and a course of PDT, reduced visual acuity was observed in 50% and only 20.8% of cases, respectively. Stabilization or increase of visual functions occurred in the remaining patients receiving a course of PDT.

[Role of fluorescence diagnosis using Photosens in patients with subretinal neovascular membrane].

The paper shows the capacity of fluorescence diagnosis (FD) in patients with subretinal neovascular membranes. Photosens was used as a photosensitizer (PS) (NIOPIK) in FD. The agent was intravenously injected in a dose of 0.05 mg/kg. To study the kinetics of tissue PS distribution, the authors employed a procedure of local fluorescence spectroscopy using a LESA-01-Biospek spectrometer, which was improved when applying the procedure for visual assessment of a visual fluorescence image. It was ascertained that the results of photodynamic therapy (PDT) should be compulsorily taken into account in processing its parameters. In some cases, PDT may be recommended on days 3, 5, and 7 after administration of an agent. By taking into account the pharmacodynamics of Photosens, 0.5 mg/kg, all patients should keep the light regime for 3 months.

[Photodynamic therapy for subretinal neovascular membranes. Communication 1. Results of treatment for age-related macular degeneration].

The purpose of the study was to assess the results of photodynamic therapy (PDT) for subretinal neovascular membranes (SNM) in age-related macular degeneration (ARMD), by using the Russian drug Photosens. According to the treatment performed, all the patients were divided into 2 groups: 1) 18 patients with the neovascular form of ARMD who received a course of PDT; 2) 14 patients with the same form who had drug therapy. Photosens (aluminum phthalocyanine) was intravenously injected in a dose of 0.05 mg/kg. The irradiation conditions were as follows: a session was carried out, using a laser at a wavelength of 675 nm, in an exposure light dose of 120 J/cm2. The number of sessions ranged from 3 to 5 a week, depending on the clinical picture of SNM. The total light dose was not greater than 500 J/ cm2. PDT showed a higher efficiency, as compared to drug therapy. PDT using Photosens increases and stabilizes visual acuity in 50% of cases, improves retinal functional activity (an increase in the mean value of a b-wave amplitude), and causes positive changes in the morphometric values of the mean neuroepithelial thickness above SNM and in the foveola.

[Experimental assessment of the capacities of use of photosense. Communication 1. Fluorescence diagnosis of epibulbar and choroid tumors].

Whether Photosense (PS) may be used in the fluorescence diagnosis (FD) of experimental epibulbar and choroid tumors is discussed. The fluorescent ability of Photosense in FD permits detection of advanced malignancies. The kinetics of concentration of PS and the selectivity of its accumulation in malignant versus normal tissues were investigated. PS is shown to be an effective photosensitizer in the FD and, possibly, photodynamic therapy of tumors.

[The first results of phase IIA of clinical studies of photodynamic therapy for subretinal neovascular membranes with photosense].

The subretinal neovascular membrane (SNM) is a common complication of diseases, such as senile macular degeneration, myopia, pseudohistoplasmic syndrome, and many others. There is no algorithm of treatment for this pathology in today's ophthalmological care; however, many authors have arrived at the conclusion that photodynamic therapy (PDT) plays a major role in solving this difficult problem. Fifteen (18 eyes) patients, including 8 (8 eyes) patients diagnosed as having senile macular degeneration and SNM and 7 (10 eyes) patients diagnosed as having complicated high-grade myopia, and 3 were diagnosed as having bilateral SNM. The Russian agent Photosense, 0.05 mg/kg, was used as a photosensitizer. PDT was performed on day 3 after administration of the agent according to the peak of accumulation and the maximum laser concentration gradient at a wavelength of 675 nm and a light dose of 120 J/cm2. Good functional and angiographic results may be observed after the first 3 months of a prospective controlled open-labeled study of the efficiency of PDT with Photosense; however, longer follow-ups and larger groups of patients are required to make a final assessment of this treatment.

[Experimental assessment of the capacities of use of photosense. Communication 2. Photodynamic therapy for epibulbar and choroid tumors].

The study was undertaken to evaluate the efficiency of photodynamic therapy of pigmented choroid and epibulbar melanoma, by using the agent Photosense. Pigmented choroid and epibulbar melanoma were identified in 50 rabbit eyes. After intravenous injection of Photosense, 0.7 mg/kg, the tumors were irradiated at 675 nm with an argon-pumped dye laser at 150 J/cm2. Photodynamic therapy with Photosense may be effective in treating pigmented choroid and epibulbar melanomas.

[Study of optical absorption of sensitizers in vivo].

The subject of the paper is study of optical absorption of sensitizers in biological tissue. The study shows that absorbance can be used as a tool that allows studying biodistribution of sensitizers and their interaction with tissue in vivo. The article presents a simple technique of determining biological tissue absorption in vivo, and discusses the results of experimental animal studies of some sensitizers.

Targeting phthalocyanines to tumor cells using epidermal growth factor conjugates.

Epidermal growth factor (EGF) was used as a vector for targeted delivery of phthalocyanines to tumor cells. The conjugates of EGF with disulfochloride aluminum phthalocyanine [Pc(Al)] and disulfochloride cobalt phthalocyanine [Pc(Co)] were synthesized. The cytotoxic activity of the conjugates against the human breast carcinoma cell line MCF-7 was determined. The cytotoxic activity of the EGF-Pc(Co) conjugate was 4.5 times higher than that of the EGF-Pc(Al) conjugate. The antitumor activity of the EGF-Pc(Co) conjugate was also studied in vivo in murine melanoma B16. Compared to free Pc(Co), intravenous injections of Pc(Co) conjugated with EGF inhibited tumor development and increased mean life span and mean survival time of experimental animals.

Antitumor activity of conjugates of the oncofetal protein alpha-fetoprotein and phthalocyanines in vitro.

The several conjugates of aluminium and cobalt complexes of phthalocyanines with human alpha-fetoprotein have been synthesized. Their cytotoxic activity against tumor cells and human peripheral blood lymphocytes was studied. The experimental data demonstrate that the cytotoxic activity of alpha-fetoprotein-phthalocyanine conjugates against three types of tumor cells of various origin is much higher (for aluminium and cobalt complexes more than 1000 and 50 times, respectively) in comparison with phthalocyanines themselves. The application of phthalocyanines as conjugates with alpha-fetoprotein makes it possible to markedly enhance the selective toxicity of phthalocyanines against human tumor cells.