Tissue engineering, rapidly developing branch of bioscience, is widely adopted for the purposes of the tissue growing using the substrate materials. Three-dimensional porous scaffolds possess a great opportunity for the directional growth of the cells and for the supplying them with nutrients. However, the complex porous structure of the scaffolds create difficulties for the measurements and control of nutrients flow. We applied optical coherence tomography (OCT) for imaging of the scaffold structure. We also investigated the possibility of using Doppler OCT to monitor the flow velocity distribution within the scaffold. The average scaffold's pore diameter has been estimated using electron microscopy. We show that with Doppler OCT it is possible to monitor complex micro-flow and estimate the shear stress (i.e. enhancing factor of cell growing) acting on the cells within the scaffold and to find the optimal input flow rate, consequently.OCT image (2 × 2 mm) of scaffold overlapped with velocity flow distribution

Confocal laser scanning microscopy (CLSM) is a modern high-resolution optical technique providing detailed image of tissue structure with high (down to microns) spatial resolution. Aiming at a concurrent improvement of imaging depth and image quality the CLSM requires the use of contrast agents. Commonly employed fluorescent contrast agents, such as fluorescent dyes and proteins, suffer from toxicity, photo-bleaching and overlapping with the tissues autofluorescence. Gold nanoparticles are potentially highly attractive to be applied as a contrast agent since they are not subject to photo-bleaching and can target biochemical cells markers associated with the specific diseases. In current report we consider the applicability of gold nanospheres as a contrast agent to enhance quality of CLSM images of skin tissues in vitro versus the application of optical clearing agent, such as glycerol. The enhancement of CLSM image contrast was observed with an application of gold nano-spheres diffused within the skin tissues. We show that optical clearing agents such as a glycerol provide better CLSM image contrast than gold nano-spheres. μmEnhancement of CLSM image contrast of skin tissues after application of gold nanoparticles as a contrast agent

Nowadays the artificial neural network (ANN), an effective powerful technique that is able denoting complex input and output relationships, is widely used in different biomedical applications. In present Letter the applying of ANN for the determination of characteristics of random highly scattering medium (like bio‐tissue) is considered. Spatial distribution of the backscattered light calculated by Monte Carlo method is used to train ANN for single and multiply scattering regimes. The potential opportunities of use of ANN for image reconstruction of an absorbing macro inhomogeneity located in topical layers of random scattering medium are presented. This is especially of high priority because of new diagnostics/treatment developing that is based on the applying gold nano‐particles for labeling cancer cells. (© 2007 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)

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