We developed an original reproducible 3D-technology for preparation of single dormant microspheres consisting of 2000 somatic cells. The dynamics of microsphere assembly from mesenchymal and epithelial cells of retinal pigment epithelium was traced using time-lapse microscopy: formation of a loose aggregate over 24 h followed by its gradual consolidation and formation of a compact viable microsphere with a diameter of 100-150 μ by day 7. The cell number in the formed microspheres remains unchanged. Reactivation observed upon fusion of epithelial and/or mesenchymal microspheres results in the formation of a united compact microtissue. The fusion dynamics reproduces spherogenesis irrespective of the initial amount of co-cultured microspheres. Reactivation via two-step induced angiogenesis opens new prospects for production of vascularized microspheres and microtissues.

This work is devoted to application of laser Raman spectroscopy to improve the fidelity of molecular computing by DNA strands. The developed method provides determination of concentrations of specific nitrogenous bases not lower than 0.03 g l −1 and the accuracy of determining the total concentration of DNA in solutions 0.02-0.04 g l −1 by the Raman spectra of DNA solutions. The method allows us to control the temperature of DNA solutions in the process of molecular computing with an accuracy better than 0.2 °C. The obtained results provide required control of the parameters of DNA solutions to increase the speed and accuracy of solving the problems in the results of molecular computing.

Fraction analysis of homocysteine in biological fluids is important for the diagnosis and studies of cardiovascular, nervous, urological, and other diseases. Measurements of total, free, and reduced homocysteine by mass spectrometry with HPLC by means of its modification with N-ethylmaleimide are proposed. The linearity and detection threshold were 0.025-10 and 0.001 μM, respectively, for reduced homocysteine fraction and 0.2-100 and 0.1 μM, respectively, for the rest fractions. The accuracy and reproducibility of the method were within 12%.