Nanochemistry and biotechnology

Interaction of highly dispersed silica and cryopreserved rams sperm
Shcherbak O.V., Lyzohub O.Yu.
Laboratory of Biotechnology Reproduction, Institute of Animal Breeding and Genetics nd. a. M.V.Zubets, National Academy of Agrarian Science of Ukraine,
1 Pogrebnyaka St., v. Chubinske, Borispol District, Kiev Region, 08321, Ukraine.
E-mail: ov19792006@gmail.com
Due to unique physicochemical, medical and biological properties (including extremely developed surface, chemical purity, hydrophilicity, significant adsorption capacity) ultra fine silica (UFS) is used as a sorbent and carrier of drugs in many fields of medicine, pharmacology, veterinary medicine etc. Depending on the method of use, it can interact with various physiological solutions, such as blood plasma or gastric acid [1-3]. It is necessary to understand the mechanism of its interaction with the components of physiological solutions for more efficient use of silica. Therefore, it is important to study the mechanism of UFS’s action, as well as to establish new opportunities for its application. Therefore, one of the important steps is to study the effect of UFS on the cells of the body in direct contact.
The aim of our research was to study the effect of 0,001% UFS concentration 200°C on the viability of cryopreserved sperm of ram. The effect of adding 0,001% UFS concentration 200°C on the viability of deconserved ejaculated sperm of rams sokilska breed (80-4016, 55-06535, 044-05828) was studied. The gametes of these rams’ breeds are chosen is due to the fact that they are stored in the Bank of Animal Genetic Resources of the Institute of Animal Breeding and Genetics of the National Academy of Agrarian Sciences of Ukraine for over 30 years and are valuable genetic material for reproduction and selection work. It was used nanomaterial brand A-300 with S = 285 m2/g (Kalush, Ukraine) in our research, which was previously calcined for 2 hours at a temperature of 200°C (UFS 200°C). The nanomaterial was added at a 0,001% concentration after thawing the gametes. The effect on the viability of cryopreserved gametes of rams was evaluated by sperm activity in percentage.
It was found, that after thawing of rams’ sperm, an average spermatozoa activity was of 41.7%1.67. This rate of gamete activity decreased within 30 minutes up to 33.3%1.67 in the control. Gametes with UFS 200°C showed activity at the level of 45.0%2.87, which is 11.7% higher compared to the control and 3.3% higher compared to the initial activity. One hour after the start of the study was observed that sperm activity in the control at the level of 20.0%2.87, which is lower by 53.0% compared to the initial activity. Gametes with UFS 200°C one hour after the start of the study had an activity of 24.2%8.46, which decreased by 42.0% compared to the initial activity. It should be noted that we have established the possibility of extending the survival time of deconserved rams sperm. The shortest survival period was observed in the control (3 hours), and in the case of adding 0.001% UFS 200°C, this figure exceeded 3.5 hours. 
So, we modeled the interaction of UFS and deconserved rams sperm in vitro. The obtained results can be used during biotechnological manipulations with cryopreserved reproductive material of farm animals, namely during artificial insemination of females and obtaining embryos outside the body. The effectiveness of such approaches will increase due to the combination of nanotechnology and reproductive biotechnology and will ensure the rational use of genetic material during its long-term storage.

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