Aim: to verify new techniques for human cadaveric vascular allografts cryopreservation, thawing and sterilization for the tissue engineering purposes. We use polydimethylsiloxane (PDMS) as a well-known, promising coolant. This allowed us to completely omit any cryoprotective or vitrifying solutions. Using of PDMS also makes possible an applying these allografts directly after freezing and decellularization and also it will also provide an opportunity to develop secure protocols of tissue— engineered vascular conduits cryopreservation. Matherial and methods. After mathematical modeling of cooling process and its validation the experiment for sealed (isolated) freezing at low temperature conditions of 30 femoral arterial segments has been conducted. The segments were at least 10 cm in length and taken from 15 cadaveric donors in the age of 65-85 years. The freezing process was carried out using the abovementioned coolant— PDMS, and then physico-mechanical properties of these allografts were evaluated with the special Instron machine. According to the results obtained, a modeling of their sterilization conditions was conducted (the grafts were freezed). Results. By physico-mechanical properties validation and restricted histological analysis it was shown that there was an accordance between freezed/thawed allografts properties and native vessels. Conclusion. The abovementioned approach for allografts cryopreservation and thawing was efficient enough for further work in this direction.
Lauk-Dubitsky S.E., Astrelina Т.А., Saprykin V.P., Fediunin A.A., Paklina O.V., Gordeev A.V., Shakurov A.V., Belikov N.V., Khaidukova I.V., Burkov I.A., Antonov E.A., Ponomarev D.E., Kobzeva I.V., Savrasov G.V., Vorobyov G.V., Brumberg V.A., Nikitina V.A., Suchkova Y.B., Dobrovol'skaya E.I., Karaseva T.V., Gubarev K.K., Bushmanov A.Yu., Samoilov A.S. A novel comprehensive approach for human vascular allografts cryopreservation and radiation sterilization for the tissue engineering industry // Saratov Journal of Medical Scientific Research, Vol. 11, Issue 4, 2015, pp. 624-632

The problem of single sperm cryopreservation can be solved by use of the microcontainers that prevent loss during manipulations. Zonae pellucidae of human and mammalian eggs are the best microcontainers, but their use is limited by risk of contamination with infectious and genetical foreign material. Alternative variants, such as cryoloops, are too labour-consuming and are not widespread. In our work we describe the technique of individual spermatozoon cryoprezervation in artificial microspheres made out of agarose gel. Agarose it is nontoxic, biologically inert and does not induce acrosome reaction. Post-thaw motility of spermatozoa cryopreserved in agarose microspheres was 64%.
Isaev, D.A. Zaletov, S.Y. Single sperm cryopreservation. Problemy Reproduktsii. 2006. V. 12; № 5, P. 43-47. (Russian) ISSN 1025-7217