We are pleased to present the third issue of JIOHS, which focuses on optical technologies of diagnostics and therapy. These are selected papers presented during Saratov Fall Meeting — 1st International Symposium on Optics and Biophotonics (September 24–28, 2013, Saratov, Russia) in the framework of the Workshops: “Optical Technologies in Biophysics and Medicine," “Nanobiophotonics," and “Internet Biophotonics." This issue includes nine representative papers that well characterize the major topics of SFM-13.

In the paper, the results of experimental investigations on the differences of wool structure of healthy mice and mice with malignant tumor(s) are represented. It is shown that destruction of wool structure happens during pathology development. Quantity of cells of external wool layer and their thickness decrease when the tumor capsule enlarges. Difference is seen even when the tumor is small. The obtained results can be used to improve optical techniques of biomedical diagnostics of cancer diseases.

It is very important to study the problem of caries and gingivitis in adolescents who are being treated for orthodontic pathology with bracket systems. The method of combined treatment which incorporates the use of medicine and laser therapy has been proved effective in caries prevention. This research aims to study clinical aspects of the effectiveness of the combined influence of the low-intensity laser "OPTODAN" with a wavelength of 0.85 μm (Scientific Development and Production Center "VEND", Saratov, Russia) in carries prevention. The research also aims to study the disinfection method of PAD with "FotoSan" ("CMS Dental", Denmark, with a wavelength of 625–635 nm, where toluidine blue is used as photosensitizer molecules) combined with regular measure to prevent gingivitis in adolescents being treated for orthodontic pathology with bracket systems. This paper presents the results of 1.5 years of clinical study of 60 12–13-year-old children. They were examined before and after the orthodontic treatment: their decayed, missing, filled teeth (DMFT), decayed, missing, filled tooth surfaces (DMFS) index and hygiene status (OHI-S) were calculated, gum inflammations were detected. Before the orthodontic treatment, their mouths were sanitized. After orthodontic appliances were placed, the children were randomly divided into two groups of 30 each. Children of the first group, while being treated with braces, took traditional preventative measures against gum inflammation and caries: occupational hygiene, local antiseptics (0.05% chlorhexidine solution), the use of remineralizing and phosphorus containing applications four times a year. The children of the second group, along with the traditional scheme of preventive measures, were treated with the devices "FotoSan" and "Optodan". Results of clinical examination of the second group have accurately proved decrease in the growth of dental caries intensity and surface caries intensity (△DMFT, △DMFS) and in gingivitis level at the end of the orthodontic treatment. So the results of our clinical research have proved the effectiveness of laser therapy and comprehensive prevention of caries and gingivitis in adolescents using bracket system.

Comparative optical study of biofluids (serum, urine, hemodialysate) by concentration change of endogenous visible fluorescence substance (VFS) has been carried out. Biofluids were collected from chronic kidney diseases (CKD) patients (Pts) as well as from healthy controls (HCs). Excitation/emission spectra are similar for all samples of biofluids differing only in intensity, which is higher for CKD Pts. Strong similarity enables the study of given biofluids from a united physical platform, proposed earlier, i.e., as nanoparticles approach. Specific spectral redistribution of visible fluorescence (VF) intensity as a result of dilution is revealed. The concentration change of VFS by dilution of samples manifests in nonlinear dependences in the scales “VF intensity–concentration" for serum and urine and in perfect linearity for hemodialysate (HD). The latter fact can be used in monitoring of hemodialysis procedure.

The antitumor efficiency of gold nanorod plasmonic photothermal therapy (PPTT) was evaluated experimentally. The rat cholangiocarcinoma line PC-1 was used as a tumor model. Exposure of tumors to 808-nm laser radiation was performed, and the noninvasive temperature monitoring of the tumor tissue was carried out using infrared imager. The growth rate kinetics and morphological alterations of transplanted liver tumors, as well as indicators of lipid peroxidation activity and autointoxication in rat serum, were studied. The activation of lipid peroxidation and the development of autointoxication were detected after PPTT. The results not only demonstrate the antitumor efficacy of the proposed therapeutic technology but also reveal the side effects in the presence of peroxidation products in systemic circulation.

Extensive research in the area of optical sensing for medical diagnostics requires development of tissue phantoms with optical properties similar to those of living human tissues. Development and improvement of in vivo optical measurement systems requires the use of stable tissue phantoms with known characteristics, which are mainly used for calibration of such systems and testing their performance over time. Optical and mechanical properties of phantoms depend on their purpose. Nevertheless, they must accurately simulate specific tissues they are supposed to mimic. Many tissues and organs including head possess a multi-layered structure, with specific optical properties of each layer. However, such a structure is not always addressed in the presentday phantoms. In this paper, we focus on the development of a plain-parallel multi-layered phantom with optical properties (reduced scattering coefficient μ^'_s and absorption coefficient μ_a) corresponding to the human head layers, such as skin, skull, and gray and white matter of the brain tissue. The phantom is intended for use in noninvasive diffuse near-infrared spectroscopy (NIRS) of human brain. Optical parameters of the fabricated phantoms are reconstructed using spectrophotometry and inverse adding-doubling calculation method. The results show that polyvinyl chloride-plastisol (PVCP) and zinc oxide (ZnO) nanoparticles are suitable materials for fabrication of tissue mimicking phantoms with controlled scattering properties. Good matching was found between optical properties of phantoms and the corresponding values found in the literature.

The results on determination of glucose and glycerol diffusion coefficients in myocardium tissue are presented. The method is based on the measurement and analysis of temporal dependence of tissue optical collimated transmittance under action of a hyperosmotic agent. This temporal tissue response is related to the rate of the agent and water diffusion in a tissue. The diffusion coefficients for tissue fluid fluxes at glucose and glycerol application to the myocardium at 20℃ have been estimated as (4.75 ± 3.40) × 10⁷ and (7.71 ± 4.63) × 10⁷ cm²/s, respectively.

Lasers have been widely used for tattoo removal, but the limited light penetration depth caused by high skin scattering property restricts the therapeutic outcome of deep tattoo. Skin optical clearing method, by introducing optical clearing agent (OCA) into skin, has shown some improvement in the effect of laser tattoo removal. In this study, the enhanced laser tattoo removal has been quantitatively assessed. OCA was applied to the skin of tattoo animal model and Q-switched Nd:YAG laser (1064 nm) irradiation was used to remove the tattoo. The skin evaluation instrument (Mexameter probe, MPA580) was applied to measure the content of tattoo pigment before and after laser treatment, and then the clearance rate of pigment was calculated. Further, Monte Carlo (MC) method was utilized to simulate the effect of skin optical clearing on light transmission in tattoo skin model. By comparing the pigment change of tattoo areas respectively treated with OCA plus laser and single laser, it was found that pigment clearance of the former tattoo area was increased by 1.5-fold. Further, the MC simulation verified that the reduced light scattering in skin could increase the effective dose of luminous flux reaching to the deep tattoo regions. It can be concluded from both experiment and theoretical simulations that skin optical clearing technique could improve the outcome of laser tattoo removal, which should be beneficial for clinical laser tattoo removal and other laser pigment elimination.

In this paper, a system supporting behavioral therapy for autistic children is presented. The system consists of sensors network, base station and a brooch indicating person's emotional states. The system can be used to measure values of physiological parameters that are associated with changes in the emotional state. In the future, it can be useful to inform the autistic child and the therapist about the emotional state of the interlocutor objectively, on the basis of performed measurements. The selected physiological parameters were chosen during the experiment which was designed and conducted by authors. In this experiment, a group of volunteers under controlled conditions was exposed to a stressful situation caused by the picture or sound. For each of the volunteers, a set of physiological parameters, was recorded, including: skin conductance, heart rate, peripheral temperature, respiration rate and electromyography. The bio-statistical analysis allowed us to discern the proper physiological parameters that are most associated to changes due to emotional state of a patient, such as: skin conductance, temperatures and respiration rate. This allowed us to design electronic sensors network for supporting behavioral therapy for children with autism.

The problem of in vivo photoluminescence diagnostics of the tissues accessible by endoscopes is discussed. The spectral imaging module attachable to conventional rigid and flexible medical endoscopes is developed and described. It is based on a double acousto-optical tunable filter (AOTF) and a specialized optical coupling system. The module provides wide field of view (FOV), absence of image distortions, random spectral access, fast spectral image acquisition at any wavelength in the visible range and accurate measurement of reflectance spectrum in each pixel of the image. Images of typical biomedical samples are presented and discussed. Their spectra are compared to the reference data.