Georgy V. Simonenko

Low-intensity indocyanine-green laser phototherapy of acne vulgaris: Pilot study

Near infrared (NIR) diode laser low-intensity (soft) phototherapy with the topical application of indocyanine green (ICG) has been suggested for treatment of acne vulgaris. Twelve volunteers with acne lesions on their faces and/or backs were enrolled in the experiment. Skin areas of the subjects that were 4 x 5 cm2 were stained with ICG solution for 5 min before laser irradiation (803 nm) at a power density up to 50 mW/cm2 for 5 to 10 min. For 75% of the subjects, a single treatment was provided and for the other 25%, eight sequential treatments over a period of a month were carried out. Observations a month after the completion of the treatment showed that only the multiple treatments with a combination of ICG and NIR irradiation reduced inflammation and improved the state of the skin for a month without any side effects. A month after treatment, the improvement was about 80% for the group receiving multiple treatments. Single treatments did not have a prolonged effect.

Destructive fat tissue engineering using photodynamic and selective photothermal effects

Destructive fat tissue engineering could be realized using the optical method, which provides reduction of regional or site-specific accumulations of subcutaneous adipose tissue on the cell level. We hypothesize that light irradiation due to photodynamic and selective photothermal effects may lead to fat cell lypolytic activity (the enhancement of lipolysis of cell triglycerides due to expression of lipase activity and cell release of free fat acids (FFAs) due to temporal cell membrane porosity), and cell delayed killing due to apoptosis caused by the induced fat cell stress and/or limited cell necrosis.

Fat tissue staining and photodynamic/photothermal effects

Cellulite is considered as a disease of the subcutaneous fat layer that appears mostly in women and consists of changes in fat cell accumulation together with disturbed lymphatic drainage, affecting the external appearance of the skin. The photodynamic and selective photothermal treatments may provide reduction the volume of regional or sitespecific accumulations of subcutaneous adipose tissue on the cellular level. We hypothesize that light irradiation of stained fat tissue at selected temperature leads to fat cell lypolytic activity (the enhancement of lipolysis of cell triglycerides due to expression of lipase activity and cell release of free fat acids (FFAs) due to temporal cell membrane porosity), and cell killing due to apoptosis caused by the induced fat cell stress and/or limited cell necrosis.

Optical anisotropy of a biological tissue under conditions of immersion clearing and without them

The optical anisotropy of a biological tissue is studied under conditions of immersion clearing of the tissue and without them. It is shown that the rate of immersion clearing of a biological tissue depends on its type and is determined by the rate of diffusion of immersion liquids into the sample. The parameters that characterize the rate of diffusion of an immersion liquid into a biological tissue are determined. The types of anisotropy of different samples of biological tissues are found. Based on the Müller matrix formalism, a model for calculating the spectrum of collimated polarized transmission of a biological tissue is constructed. Comparison of calculated and experimental transmission spectra of biological tissues showed their good quantitative coincidence.

LCD Optimization and Modeling

The application of the LCD modeling and optimization system, LCD DESIGN, for the design and development of new advanced LCD configurations was demonstrated. The software includes a powerful optimization module that allows for spectral and angular averaging, thus enabling the production of LCDs with wide viewing angles, achromatic (black/white) switching, and fast response time. We describe the basic principles of the software development and present several examples of LCD optimization in various electro-optical modes. A brief review of our results of LCD optimization and modeling using LCD DESIGN software is also given.

Thermal action on the lipocells

Distinction of hypodermic lipocells of practically healthy people and patients with NIDDM to temperature eposure is revealed. This distinction is caused not only by the peak size difference of lipoblasts in practically healthy people and in insulin metabolism disorders, but in the greater degree - by distinction of morpho-functional properties of lipocell membrane of practically healthy donors and patients with noninsulindependent mellitus.

Measurement of an optical anisotropy of biotissues

The comparison method of color coordinates measurements for estimation of the optical anisotropy of tissue is suggested. The anisotropy of form of fibrous tissue was measured, it makes (Delta) n equals 0.001 for both types of studied tissues. We have suspected that optics of the muscle tissue is similar to optical properties of a uniaxial crystal, which optic axis is parallel to fibrils of a tissue. Due to more complicated structure scleral tissue optics is similar to optics of a biaxial crystal. The estimated value of an optical anisotorpy of the clarified sclera allowed us to evaluate the mean length of collagen fibrils of about 2 mm at mean radius of fibrils of 50 nm.

28.1: LCD Optimization and Modeling

The application of the LCD modeling and optimization system LCD DESIGN for the design and development of the new advanced LCD configurations is demonstrated. The software includes a powerful optimization module, that allows for the spectral and angular averaging, thus enabling to produce LCD with wide viewing angles, achromatic (black/white) switching and fast response time. We describe the basic principles of the software development and present several examples of the LCD optimization in various electrooptical modes. A brief review of our results of LCD optimization and modeling using LCD DESIGN software is also given.

ICG laser therapy of acne vulgaris

The near-infrared (NIR) laser radiation due to its high penetration depth is widely used in phototherapy. In application to skin appendages a high selectivity of laser treatment is needed to prevent light action on surrounding tissues. Indocyanine Green (ICG) dye may provide a high selectivity of treatment due to effective ICG uploading by a target and its narrow band of considerable absorption just at the wavelength of the NIR diode laser. The goal of this study is to demonstrate the efficacy of the NIR diode laser phototherapy in combination with topical application of ICG suggested for soft and thermal treatment of acne vulgaris. 28 volunteers with facile or back-located acne were enrolled. Skin sites of subjects were stained by ICG and irradiated by NIR laser-diode light (803 or 809 nm). Untreated, only stained and only light irradiated skin areas served as controls. For soft acne treatment, the low-intensity (803 nm, 10 - 50 mW/cm2, 5-10 min) or the medium-intensity (809 nm, 150 - 190 mW/cm2, 15 min) protocols were used. The single and multiple (up to 8-9) treatments were provided. The individual acne lesions were photothermally treated at 18 W/cm2 (803 nm, 0.5 sec) without skin surface cooling or at 200 W/cm2 (809 nm, 0.5 sec) with cooling. The results of the observations during 1-2 months after the completion of the treatment have shown that only in the case of the multiple-wise treatment a combined action of ICG and NIR irradiation reduces inflammation and improves skin state during a month without any side effects. At high power densities (up to 200 W/cm2) ICG stained acne inflammatory elements were destructed for light exposures of 0.5 sec. Based on the concept that hair follicle, especially sebaceous gland, can be intensively and selectively stained by ICG due to dye diffusion through pilosebaceous canal and its fast uptake by living microorganisms, by vital keratinocytes of epithelium of the canal and sebaceous duct, and by rapidly proliferating sebocytes, new technologies of soft and thermal acne lesions treatment that could be used in clinical treatment of acne were proposed.

Choosing the optimum design for an optical shutter based on a π-cell

Computer modelling is used to determine the conditions for optimizing the design of an optical shutter that uses a π-cell.