"Nanobiotechnology for health-care"

The effects of nanobiopolymers on morphofunctional state of cryopreserved testicular tissue
N.O. Volkova, M.S. Yukhta, L.V. Sokil, L.G. Chernyshenko, L.V. Stepanyuk, A.M. Goltsev
Institute for Problems of Cryobiology and Cryomedicine, Natl. Acad. of Sci. of Ukraine, Kharkov
E-mail: volkovana781@gmail.com
Now cryopreservation of testis tissue is a promising approach to save fertility in prepubertal boys undergoing gonadotoxic therapies. The using of nanobiopolymers as a basis of rehabilitation medium can be effective for the increasing of morphofunctional state of cryopreserved immature testicular tissue. 
This study represents a comparative evaluation of the effect of biopolymers (bovine serum albumin) in combination with gold nanoparticles (AuNPs) on morphofunctional characteristics of cryopreserved seminiferous tubules.
The AuNPs (Sigma-Aldrich, USA) were obtained by citrate synthesis with an initial metal concentration of 45 μg/ml. The average size of AuNPs was 15 nm. The tissue fragments after cryopreservation-thawing were incubated in Leibovitz's medium supplemented with bovine serum albumin (BSA) in concentrations of 50 g/l and AuNPs in concentrations of 2, 4, 6 or 10 μg/ml. Histomorphometric data, MTT-test, total protein level, total activity of the antioxidant defense system (TAS) was determined in the samples after 30 min incubation. Tissue fragments incubated under the same conditions without AuNPs were taken as a control. The results were processed with Student's t-test using Excel software.
The use of low concentration of AuNPs (2 and 4 μg/ml) did not lead to significant changes in the studied indexes. The AuNPs application in the concentrations of 10 μg/ml resulted in a decrease of TAS and metabolic activity as well as in an increase of the number of necrotic cells in histological samples compared with the control. The analysis of the total TAS activity, MTT-test and histomorphometric data showed that the combination of the BSA 50 g/l with AuNPs 6 μg/ml was the most optimal for rehabilitation of cryopreserved seminiferous tubules. 
The obtained data can be used for substantiation and development of effective rehabilitation methods for cryopreserved seminiferous tubules using the combination of biopolymers and nanoparticels.
This work was supported by the program of the National Academy of Science of Ukraine «Support for the development of priority areas of scientific research» (code 6541230), contract number 2.2.6.130.