Platelet-Rich Plasma in Vitrification; is it Helpful or Harmful?

Human and animal studies on cryoprotectants and freezing solutions are still needed to establish a simple yet reliable protocol and increase the success of cryopreservation. The main aim of this study was to evaluate the short- and long-term effects of platelet-rich plasma, a well-known antioxidant substance due to its contents including bioactive molecules and growth factors, on whole ovarian tissue cryopreservation. Fresh tissues (control group, G1) were subjected to histological tissue processing without any treatment. Ovaries treated with platelet-rich plasma (PRP)-supplemented vitrification solution were subjected to tissue processing without cryostorage group 2 (G2) or following six months of cryostorage group 3 (G3). Steps in G2 and G3 were also performed for group 4 (G4) and group 5 (G5), respectively, except that the vitrification solution was supplemented with fetal bovine serum. PRP was activated with calcium chloride (CaCl2) after double centrifugation. Ethylene glycol, dimethyl sulfoxide, and sucrose were used as cryoprotective agents in all groups. Histomorphological changes were evaluated with the semi-quantitative histochemical-scoring algorithm. Apoptotic and antiapoptotic effects and intercellular connections were evaluated with immunohistochemical staining of Bax, Bcl-2, Caspase-3 (C3), Connexin-43 (Cx-43), and TUNEL analysis. Cryopreservation with PRP-supplementation (G3) significantly increased tissue degeneration (p<0.05). There was an increase in the number of degenerated both primary and secondary follicles (p<0.05), and an increase in the immune expression of Bax, C3 and Cx-43 and TUNEL assay in G3 was observed compared to other groups (p<0.05). Since the morphology of primordial follicles was more preserved than other follicles in all groups, primordial follicles were not included in the follicle count. Our study suggested that cryopreservation with PRP-supplemented vitrification solution caused excessive damage to rat ovaries. We assumed that CaCl2 might have further provoked this cellular damage.

Automated summary

This study aimed to evaluate the effects of platelet-rich plasma on the cryopreservation of ovarian tissue. The results showed that cryopreservation with PRP-supplemented vitrification solution caused excessive degeneration of rat ovaries, possibly due to the activation of calcium chloride.