Neoglycolipids Micelle-like Structures as a Basis for Drug Delivery Systems

Targeted drug delivery is one of the most promising tasks of nanomedicine, as this is a real way to increase the effectiveness of therapeutic effects against many diseases. In this regard, the development of new inexpensive highly effective stimulating and non-immunogenic drug delivery systems (DDS) is of great importance. In this work new molecular candidates were proposed and studied for the creation of such systems based on the use of new compounds, neoglycolipids. It is shown that these compounds are capable of self-association in aqueous solutions and can serve as potential carriers of drug compounds with targeted delivery determined by their terminal groups (in particular, glycans). The processes of their associates formation and features of their structure are investigated. The results show that these selforganizing nanoscale systems can be used as a basis for developing new drug delivery systems. Keywords: neoglycolipids, micelle-like structures, small-angle X-ray scattering, molecular dynamics simulatio

RECURRENT DATA PROCESSING IN SPECTRAL OPTICAL COHERENCE TOMOGRAPHY BASED ON KALMAN FILTERING

The method of dynamic data processing in spectral optical coherence tomography based on Kalman filtering is suggested. Adaptive choice possibility of necessary number of spectral samples to ensure required resolution for a particular investigated sample is shown. Examples of experimental data processing obtained at biological objects investigating are presented

DYNAMIC PARAMETERS ESTIMATION OF INTERFEROMETRIC SIGNALS BASED ON SEQUENTIAL MONTE CARLO METHOD

The paper deals with sequential Monte Carlo method applied to problem of interferometric signals parameters estimation. The method is based on the statistical approximation of the posterior probability density distribution of parameters. Detailed description of the algorithm is given. The possibility of using the residual minimum between prediction and observation as a criterion for the selection of multitude elements generated at each algorithm step is shown. Analysis of input parameters influence on performance of the algorithm has been conducted. It was found that the standard deviation of the amplitude estimation error for typical signals is about 10% of the maximum amplitude value. The phase estimation error was shown to have a normal distribution. Analysis of the algorithm characteristics depending on input parameters is done. In particular, the influence analysis for a number of selected vectors of parameters on evaluation results is carried out. On the basis of simulation results for the considered class of signals, it is recommended to select 30% of the generated vectors number. The increase of the generated vectors number over 150 does not give significant improvement of the obtained estimates quality. The sequential Monte Carlo method is recommended for usage in dynamic processing of interferometric signals for the cases when high immunity is required to non-linear changes of signal parameters and influence of random noise

СOMPUTATIONAL COMPLEXITY ANALYSIS OF RECURRENT DATA PROCESSING ALGORITHMS IN OPTICAL COHERENCE TOMOGRAPHY

The paper deals with the basic principles of signals representation in optical coherence tomography with the usage of dynamic systems theory formalism. Computational complexity of algorithms for dynamic estimation of signals parameters is analyzed, such as extended Kalman filter and sequential Monte-Carlo method. It is shown that processing time of one discrete-time sample of the signal by extended Kalman filter increases polynomially with sizes of parameters vector and observation vector. Processing time of one discrete-time sample of the signal by sequential Monte-Carlo method depends linearly both on sizes of parameters vector and observation vector, and on the number of generating random vectors. Experimental results of processing time measurement by each algorithm are described. It is shown that processing time of the signal containing 500 discrete-time samples by extended Kalman filter in the case of the simplest model is approximately equal to 0.1 seconds and increases several times with complication of the model. Processing time of the same signal by sequential Monte-Carlo methods with fixed number of generated random vectors is equal to 0.7 seconds and slightly increases with complication of the model, approximately by 1.5 times. Obtained results may be used for estimation of expected data processing time by recurrent dynamic estimation algorithms in optical coherence tomography systems

STUDY OF SURFACE LAYERS MICROSTRUCTURE FOR PLANT TISSUE BY OPTICAL COHERENCE MICROSCOPY

The surface layers microstructure of biological tissue on the example of plant fruit exocarp was investigated by spectral optical coherence microscopy with tunable wavelength in the 1305 75 nm range and by the method of correlated optical coherence microscopy at the mean wavelength value equal to 940 nm. The experiments were performed for the intact and defect structures, and calculation of the surface profile of exocarp was performed

FABRICATION OF TISSUE-SIMULATIVE PHANTOMS AND CAPILLARIES AND THEIR INVESTIGATION BY OPTICAL COHERENCE TOMOGRAPHY TECHNIQUES

Methods of tissue-simulative phantoms and capillaries fabrication from PVC-plastisol and silicone for application as test-objects in optical coherence tomography (OCT) and skin and capillary emulation are considered. Comparison characteristics of these materials and recommendations for their application are given. Examples of phantoms visualization by optical coherence tomography method are given. Possibility of information using from B-scans for refractive index evaluation is shown

Quasi-Atomistic Approach to Modeling of Liposomes

Small-angle X-ray scattering is an important structural tool for studying biological membranes; however, interpretation of scattering data remains a challenging problem. In most cases, analysis makes it possible to determine some structural parameters and the electron density profile of lipid bilayers, but no methods providing more detailed information (e.g., about the structural organization of vesicles) have been proposed yet. An approach making it possible to determine the main integral characteristics of liposomes using small-angle scattering is presented in this study. Within this approach a quasi-atomic model of liposome is built from individual lipid molecules, which form a sphere or a hollow ellipsoid. The method has been implemented in a computer program, verified on experimental small-angle X-ray scattering data, and proposed to analyze the structure of lipid vesicles and their interactions with proteins