Histological study of platelet rich plasma (PRP) added freezing solution in rat ovarian tissue vitrification

It is possible to preserve fertility especially in the prepubertal age and those who want to postpone the desire for fertility in today's conditions. The cure is provided in some cancers with improved treatment protocols, but ovarian dysfunction is inevitable after chemotherapeutic drugs and/or radiotherapy. Methods such as oocyte and embryo cryopreservation to protect fertility are among the treatment options, but these require pre-stimulation protocols. There is no time for ovarian stimulation procedures in patients who should undergo rapid chemoradiotherapy. Ovarian cryopreservation provides an alternative treatment option in these cases. Today, healthy pregnancies have been reported due to ovarian tissue cryopreservation. Successful specimens of ovarian cryopreservation are still available in the literature but are still considered to be experimental studies and need to be developed. Several substances have been tried and positive results have been obtained for cryopreservation and reduction of cellular damage caused by cryoprotectant agents. The availability of platelet-rich plasma in order to reduce cryodamages has been the subject of our study. Platelet-rich plasma (PRP) is a blood product obtained by condensation of platelets. It is frequently used in regenerative medicine because of its rich growth factors. The risk of animal substances or infectious pathogens transmission is eliminated by the use of PRP in the mediums as an alternative to fetal bovine serum (FBS) for supporting cellular functions. Moreover, the possibility of an immune reaction is reduced due to the autologous use of PRP. In order to develop cryopreservation techniques, tissues were frozen by adding PRP to the vitrification solution in whole ovarian tissue cryopreservation procedure. Tissues are grouped as control (Group 1), vitrification group treated with PRP added freezing solution (Group 2), and vitrification group treated with FBS added freezing solution (Group 3). After thawing, tissues were stained by histochemical, immunohistochemical and immunofluorescent staining methods. HE, PAS and Mallory Trichrome stainings were performed by histochemically. The expression of caspase 3 and TUNEL analysis were investigated by immunofluorescence staining methods. The expressions of connexin 43, Bax, Bcl-2 and caspase 3 were investigated by immunohistochemical staining methods and TUNEL analysis was also performed. In conclusion, degenerations due to vitrification were observed both in Group 2 and Group 3 compared to the control group. However, CaCl2 used to activate PRP in Group 2 was found to aggregate the harmful effects of vitrification and increase the degeneration of ovarian tissue and prevent the possible positive effects of PRP. In both experimental groups, it was noted that the primordial follicles were preserved, but degeneration of the follicles at the advanced stages of follicular development was increased. In the light of the findings, it was concluded that the rat ovarian cryopreservation should be performed as cortical parts instead of whole ovarian tissue. We concluded that the results should be analyzed by applying both vitrification and slow freezing methods.