Nina A. Lakodina

Glucose and Mannitol Diffusion in Human Dura Mater

An in vitro experimental study of the control of the human dura mater optical properties at administration of aqueous solutions of glucose and mannitol has been presented. The significant increase of the dura mater optical transmittance under action of immersion liquids has been demonstrated. Diffusion coefficients of glucose and mannitol in the human dura mater tissue at 20 degrees C have been estimated as (1.63 +/- 0.29) x 10(-6)cm(2)/s and as (1.31 +/- 0.41) x 10(-6) cm(2)/s, respectively. Experiments show that administration of immersion liquids allows for the effective control of tissue optical characteristics that make dura mater more transparent, thereby increasing the ability of light penetration through the tissue.

In vitro and in vivo study of dye diffusion into the human skin and hair follicles

We present experimental results on the in vitro and in vivo study of dye diffusion into human skin and hair follicles. We have studied some commercially available dyes for potential using in the laser selective thermolysis. The degree and the depth of hair follicle dyeing inside the skin were determined. For hairs in different stages the sebaceous gland was stated as a reservoir for a dye administration. It was found that the penetration depth of dyes is about 1.2 mm from the skin surface. We have developed the biocompatible Indocyanine Green lotions and the method for in vivo dyeing and dye in depth monitoring. Shift on 16-21 nm of absorption peak of Indocyanine Green to the longer wavelengths due to Indocyanine Green binding with cell proteins in the human skin was found.

In vivo investigation of the immersion-liquid-induced human skin clearing dynamics

The results of an in vivo investigation of human skin clearing caused by the immersion-liquid-induced matching of the refractive indices are reported for the first time. It was established that subcutaneous injections of a glucose solution produce a significant long-term suppression of the light scattering in the skin dermis, which is an important factor ensuring an increase in efficacy of the optical tomography, photodynamic therapy, and photodestruction of deep objects.

Human sclera dynamic spectra: in-vitro and in-vivo measurements

Experimental results on the optical properties of the human eye sclera controlled by administration of osmotically active chemicals, such as propylene glycol and glucose are presented. Administration of chemical agents induces diffusion of matter and as a result equalization of the refractive indices of collagen and ground material. Experimental study of influence of propylene glycol and glucose on reflectance and transmittance spectra of human eye sclera was performed. In vitro diffusion reflectance spectra of the whole human eye and transmittance spectra of the sclera samples were investigated. In vivo measurements were fulfilled on a rabbit eyes. The significant increase of transmittance and decrease of reflectance of human eye sclera and rabbit eye under action of osmolytic liquids was demonstrated. The matter diffusion coefficient for the scleral samples impregnated by glucose solution was estimated; the average value is 1.27x10-5 ± 2.26x10-6 cm2/sec. The results are general and can be used to describe many other fibrous tissues.

Estimation of glucose diffusion coefficient in scleral tissue

Results of experimental and theoretical study of the optical properties of the eye sclera controlled by administration of osmotically active chemical, such as glucose, are presented. Glucose administration induces the diffusion of matter and as a result the equalization of the refractive indices of collagen fibrils and base material, and corresponding changes of transmittance spectra of scleral tissue. Transmittance spectra of the human scleral samples impregnated by glucose were measured. The significant increase of transmittance under action of osmotic liquid was observed. The diffusion coefficient of glucose within scleral tissue was estimated; the average value is 3.45 X 10-6 +/- 4.59 X 10-7 cm2/sec. The results are general and can be used to describe many other fibrous tissues impregnated by osmotically active chemical agents.

Osmotical liquid diffusion within sclera

We present experimental results of investigation of the optical properties of the human eye sclera controlled by administration of osmotically active chemical, such as glucose solution with various concentrations. Administration of chemical agent induces diffusion of matter and as a result equalization of the refractive indices of collagen and ground material. Results of experimental study of influence of osmotical liquid (glucose solution) on reflectance and transmittance spectra of human sclera are presented. In vitro reflectance and transmittance spectra of the human sclera samples were investigated by commercially available spectrophotometer CARY-2415. The significant increasing of the transmittance and decreasing of the reflectance of human sclera samples under action of osmotical solutions were demonstrated. Results of our study show that the degree of the sclera samples clearing is increased with increasing of the chemical agent concentration in solution. The diffusion coefficients of glucose solution with various concentrations within scleral tissue was estimated.

Diffusion of glucose solution through fibrous tissues: in-vitro optical and weight measurements

The diffusion of glucose with various concentrations through human sclera and cerebral membrane in vitro was studied. The dynamics of this process was monitored by time-dependent weight and optical measurements. Glucose administration induces the diffusion of matter and as a reslut the equalization of the refractive indices of collagen fibrils and ground material, and corresponding changes of transmittance spectra of fibrous tissue. Transmittance spectra of the human scleral and cerebral membrane samples impregnated by glucose were measured. Investigation of diffusion process in scleral samples, previously dried and swelled in distillated water was performed. Experimental results are presented.

In-vitro study of control of human dura mater optical properties by acting of osmotical liquids

We present experimental results and computer modeling of investigation on the optical properties of the human dura mater controlled by administration of osmotically active chemical, such as mannitol and glucose solutions with various concentrations. Administration of chemical agent induces diffusion of matter and as a result equalization of the refractive indices of collagen and ground material. Results of experimental study of influence of osmotical liquids (mannitol and glucose solutions) on reflectance and transmittance spectra of the human dura mater are presented. The significant decreasing of the reflectance and increasing of the transmittance of the human dura mater samples under action of osmotical solutions were demonstrated.

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.

In vitro study of penetration of magnetic particles into the human skin

We present experimental study of penetration of magnetic particles into the human skin in vitro. The administration of the particles through he skin into the body leads to localization and retention of the particles at the desired site. This technology can be used for selective damage of tumor cells by hyperthermia or to remove unwanted or excess hair. The maximal depth of particle penetration into the skin achieved in this paper was 0.7mm.