Results of intraoperative photodynamic therapy (IOPDT) in patients with gastric cancer are represented in the article. The study included 240 patients with gastric cancer stage II-IV (Т3-4N0-3M0-1) with  evident or suspected peritoneal dissemination who underwent  examination and treatment in P.Herzen Moscow Oncology Research  Institute. The group 1, the study group, included 140 patients who  underwent nominally curative or palliative surgery for locally  advanced and disseminated gastric cancer with IOPDT as additional  intraoperative intervention for antiblastics and cancer treatment. The group 2, the control group, included 100 patients who also  underwent nominally curative or palliative surgery (equal to extent  of surgery in patients from the study group) for locally advanced and disseminated gastric cancer and no intraoperative implication of physical or chemical treatment methods. IOPDT did not worsen a course of early post-operative period, did not impact on severity of  post-operative complications and was not associated with increase of post-operative mortality. IOPDT allowed for improvement of 1-year  and 3-year disease-specifi c survival rates: by 16.1% and 16.7%,  respectively. For nominally curative resections, median survival, 1- year and 3-year disease-specifi c survival rates were improved by 14 months, 17.8% and 31.3%, respectively. For R1, R2 resections,  IOPDT improved 1-year disease-specifi c survival rates by 16.4%. Additionally, for nominally curative resections IOPDT did not increase the recurrence rate and improved median recurrence-free survival,  1-year and 3-year recurrence-free survival rates by 16 months,  27.2% and 25.4%, respectively. 

Current paper presents the results of the system development for intracranial implantation aimed on therapy and prevention of brain gliomas relapse. The main property of the system, in prospective,  will be to direct the growth of glioma cells localized in the region  adjacent to the site of the removed tumor along the fi bers towards  the proximal part of the fiber-optic scaffold (neuroport). Such  approach will allow carrying out cells diagnostics by the  photoluminescence signal and provide subsequent destruction of  malignant cells by photodynamic action. Besides, this system could  be used for monitoring the processes occurring in the probed area in order to control the possible relapses. The localization of cells along  the fi ber structures covered with gelatin compound, which is the  source of amino acids during cultivation, was shown during the glioma cells growth dynamics study. Moreover, four different designs of intracranial scaffold models, serving as ports for diagnostic and therapeutic laser radiation delivery, were developed and  successfully tested in the framework of the research. The results  obtained on the rats brain with induced tumors (glioma C6) after  neuroport implantation demonstrate sufficiently intense fluorescence in the tumor bed after intravenous injection of the  nonmetallic sulfonated phthalocyanine based photosensitizer, and a  pronounced photodynamic effect leading to total destruction of the  tumor. In this way, the results of this study open the prospects of creating the neuroport with an internal fi ber structure that focuses the glioma cells growth.

The article is devoted to the development and evaluation of the effi ciency of photodynamic therapy (PDT) with photosensitizer photolon with additional interstitial laser irradiation in patients with head and  neck basal cell skin cancer (BCSC). Treatment was performed in 55  patients. On the fi rst stage, all patients underwent photodynamic  therapy with interstitial irradiation using fl exible optical fi bers with  cylindrical diffuser, on the second stage PDT with distant delivery of  laser at a dose of 50-300 J/cm2 was carried out. During the follow- up period of 6 months to 4 years in 13 (23.6%) of the 55 patients a  recurrence of the disease was diagnosed. A higher rate of recurrence was in the group of patients who underwent PDT for recurrent  neoplasms compared with patients with primary disease (37.5% and 4.3%, respectively), in patients with endophytic growth of the tumor compared to patients with exophytic component (30.0% and 16.0%,
respectively) and in patients with large tumors (up to 2.0 cm – 14.3%, from 2.0 to 5.0 cm – 16.7% and more than 5.0 cm – 54.4%).

Bacteriochlorins as the antimicrobial photosensitizers have a promising future in the face of the unrelenting increase in antimicrobial resistance. The goal of this study was to investigate the infl uence of lipophilicity and number of positively charged  substituents in these molecules on the photodynamic inactivation  (PDI) of biofi lm bacteria in vitro. Testing how bacteriochlorin  derivatives with different properties affect microbes will allow to  determine the optimal ratio of these parameters within a single  molecule. We have investigated 4 bacteriochlorin derivatives, all of  which were synthesized in Organic Intermediates and Dyes Institute. These were: hydrophobic neutral meso-tetra(3-pyridyl)  bacteriochlorin (ВС1), amphyphilic tetracationic meso-tetra(1- undecyl-3-pyridyl)bacteriochlorin tetrabromide (ВС2), hydrophilic  tetracationic meso-tetra[1-(4'-bromobutyl)-3-pyridyl]bacteriochlorin  tetrabromide (ВС3) and octacationic meso-tetra[1-(4'-pyridiniobutyl) -3-pyridyl]bacteriochlorin octabromide (ВС4) . The water-soluble  cationic bacteriochlorin derivatives showed the most effective PDI of  bacteria in biofi lms. While tetracationic BC3 caused total inactivation of S. aureus 15, octacationic BC4 was bactericidal for P. aeruginosa  32 to the same degree (>99.999%). Interestingly, increasing the  number of cationic substituents from 4 to 8 in bacteriochlorin  molecules enhances bactericidal action against gram-negative  bacteria in biofi lms. The lack of charge-carrying groups and high  degree of lipophilicity of PS have negative impact on PDI of biofi lm  bacteria. Bacterial membrane damage as a result of PDI can be one of the causes of cell death.

Staphylococcus aureus is one of the major reasons for nosocomial infections that often cause post-surgery wound infectious complications. Prevalence in hospitals as well as occurrence in the  community of the clinical isolates of methicillin-resistant  Staphylococcus aureus (MRSA) leave health professionals without  effective means of control over the infection. Complications caused  by MRSA lead to longer hospital stay and higher lethality rates. Due  to the infected wounds treatment issues and high mortality rate it is  important to introduce efficient alternatives to traditional means of  treating and preventing wound infections into the clinical practice of  inpatient surgical units and burn care facilities. It should be hard for bacteria to develop resistance to these treatment methods and measures of preventive care. Antimicrobial action of the 400-470 nm radiation attracts a lot of attention lately. Shortwave visible radiation has distinct advantages over UVC and UVB given the generally acknowledged skin injury risks and risks of development of cancer resulting from the ultraviolet exposure. In comparison with the  photodynamic therapy the 400-470 nm radiation does not require  exogenous photosensitizers with their challenging delivery to a biofilm lying deep within a tissue. Despite research being in its  infancy, in vitro and in vivo studies performed to inactivate clinically  signifi cant isolates of bacteria characterized by antibiotic resistance  suggest that the phototherapy technology using the 400-470 nm  radiation has the potential to treat and prevent surgical and burn  wound infections. In this paper effectiveness of 400-470 nm  radiation for the inactivation of strains of MRSA is analyzed.