The development and the spectral research of unique coating as crystalline nanoparticles of IR photosensitizers were performed for the creation of hydroxyapatite implants with photobactericidal properties. It has been proved that by the interaction of nanoparticles covering implant with the polar solvent, which simulates the interaction of the implant with the biocomponents in vivo (fast proliferating and with immunocompetent cells), photosensitizers nanoparticles change the spectroscopic properties, becoming fluorescent and phototoxic. Thus, the developed coating based on crystalline photosensitizer nanoparticles with studied specific properties should have antibacterial, anti-inflammatory effect by the photodynamic treatment in the near implant area. This research opens the prospect of the local prevention of inflammatory and autoimmune reactions in the area of implantation. The results of the study suggest a promising this technology in order to create implants with photobactericidal properties.

The objective – to assess tolerability, safety and immediate results of treatment of patients with oral leukoplakia using photodynamic therapy (PDT) with a photosensitizer photolon. The study included 40 patients (7 men, 33 women) with morphologically verified leukoplakia of the oral mucosa. The average age – 55±14 years. Number of treated foci – 109 (1 to 8). Photolon was administered intravenously at doses of 1.7-2.5 mg/kg. Photoirradiation («UPL PDT», Belarus, λ = 660±5 nm) was performed 2.5-3 h after administration: light exposure dose varied from 25 to 100 J/cm2, power density of 0.07 to 0.32 W/cm2, the duration of one field photoirradiation – from 2 to 13.5 min and according to its linear dimensions. The effectiveness of treatment was assessed 1-2 months after PDT by clinical data. Complete regression of foci recorded in 95% of cases (n=38), partial – in 5% (n=2).The follow-up period varied from 1 to 30 months. Full-epithelialization of the wound defect occurred within the period of 3-6 weeks after treatment. Photodynamic therapy may be recommended for patients with circumscribed or widespread oral leukoplakia as a simple, well-tolerated and effective option. Keywords: photodynamic therapy, photolon, oral leukoplakia.

The review is on treatment of keratoacanthomas using photodynamic therapy. The defining characteristic of keratoacanthoma among epithelial tumors is a rapid spontaneous regression in the case of typical keratoacanthoma and long-term persistence, recurrence and common malignant transformation to squamous cell carcinoma in the case of atypical keratoacanthoma. In recent years, photodynamic therapy which is an effective method of treatment of different types of cancer and pre-cancer diseases of the skin including actinic keratosis, Bowen’s disease, basal cell carcinoma, is increasingly used in clinical practice. There are few data for photodynamic therapy in the treatment of keratoacanthoma. The analysis of the literature shows that using of photodynamic therapy in the set of treatment modalities in patients with keratoacanthoma improves the efficacy and reduces the terms of the therapy. In all investigations except one there was complete tumor regression in 100% patients with keratoacanthoma who underwent photodynamic therapy. In one study complete tumor regression was observed in 66.7% of patients with atypical keratoacanthoma after photodynamic therapy. The follow-up of patients in all analyzed studies accounted for at least 2-3 years. During this time none of the patients had evidence for recurrence. This approach has minimal restrictions for application. Thus, photodynamic therapy may become a therapeutic alternative to surgical treatment of keratoacanthoma with good clinical and cosmetic results.

The review is on opportunities and possibilities of application of photodynamic therapy in clinical practice. The advantages of this method are the targeting of effect on tumor foci and high efficiency along with low systemic toxicity. The results of the set of recent Russian and foreign clinical trials are represented in the review. The method is successfully used in clinical practice with both radical (for early vulvar, cervical cancer and pre-cancer, central early lung cancer, esophageal and gastric cancer, bladder cancer and other types of malignant tumors), and palliative care (including tumor pleuritis, gastrointestinal tumors and others). Photodynamic therapy delivers results which are not available for other methods of cancer therapy. Thus, photodynamic therapy allows to avoid gross scars (that is very important, for example, in gynecology for treatment of patients of reproductive age with cervical and vulvar cancer), delivers good cosmetic effect for skin tumors, allows minimal trauma for intact tissue surrounding tumor. Photodynamic therapy is also used in other fields of medicine, such as otorhinolaryngology, dermatology, ophthalmology, orthopaedics, for treatment of papilloma virus infection and purulent wounds as antibacterial therapy.

The results of the clinical observation of patient with recurrent basal cell skin carcinoma of the parietal region occurred in 4 years after radiation therapy are represented. The patient underwent photodynamic therapy (PDT) using photosensitizer fotoditazin at a dose of 1.0 mg/kg; the laser power density was 0.45 W/cm2 , the laser energy density – 300 J/cm2 . Tolerability of the treatment was satisfactory. One year after treatment there was a cosmetically satisfying soft normotrophic scar with no attachment to underlying tissues in the site of the treatment of basal cell carcinoma. According to cytological study tumor cells were not detected. For five-year follow-up there was no recurrence.