The Use of Fullerene C60 to Preserve Testicular Tissue after Cryopreservation

Abstract

Autologous transplantation of cryopreserved fragments of an immature testis is an actively developing approach to save fertility in patients facing a gonadotoxic therapy. The use of bioavailable fullerene C60 as a powerful antioxidant opens up a new potential for the prevention and correction of ischemic-reperfusion pathological processes in tissues including those associated with freezing-thawing procedure. In this work, we aimed to study the antioxidant status, apoptotic/necrotic processes, and morphological characteristics of cryopreserved fragments of the seminiferous tubules of testis (CrFSTT) of immature rats after incubation in media with different concentrations of fullerene C60 (10, 15, and 20 μg/mL). Our results indicated that the addition of C60 in a concentration of 15 μg/mL decreased ROS production, cytochrom C release, and degree of histological damage of spermatogenic epithelium as well as increased the activity of the mitochondria, antioxidant defense system, and cell density in histological sections of CrFSTT compared to the control. Fullerene C60 at investigated concentrations did not impact significantly on apoptosis in cells of CrFSTT but, after incubation with 15 μg/mL C60, a percentage of living cells was 1.2-fold higher and a value of necrotic ones in this group was 1.6-fold lower than the control samples ( p < 0.05 ). Relative amount of cells of the spermatogonia germ layer did not differ between the studied concentrations. The general analysis of obtained data showed that the C60 addition in the concentration of 15 μg/mL was the most optimal for the rehabilitation of CrFSTT. The results can be used for the development of an effective rehabilitation medium for the cryopreserved testicular tissue.

Reduction of cryopreservation‐induced structural, functional and molecular damages in ram sperm by hydrated C60 fullerene

“…The binding ability of C 60 HyFn mainly to the mitochondria in the cell (Foley et al, 2002) is important for the protection of mitochondria, which are extremely sensitive to oxidative damage (Rajender et al, 2010). In a recent study (Volkova et al, 2021), C 60 HyFn has also been reported to prevent the decrease in the activity of mitochondria during cryopreservation of testicular tissue. In this study, the addition of 800 nM C 60 HyFn significantly increased the percentage of sperm with highly active mitochondria in…”

“…On the other hand, it is emphasized that C 60 HyFn reduces apoptosis by inactivating caspases, whereas C 60 dissolved in tetrahydrofuran solution increases apoptosis by activating caspases, so the effects of C 60 solvents on apoptosis are very important (Harhaji et al., 2008). In a recent study, C 60 HyFn has been reported to reduce the release of cytochrome C, which leads to caspase activation during cryopreservation of testicular tissue (Volkova et al., 2021). In this study, the addition of all C 60 HyFn concentrations significantly reduced DNA fragmentation and caspase‐3 activation in frozen–thawed ram semen compared to control.…”