Research On The Effect Of Static Magnetic Field Assisted Rewarming On Oxidative Damage Of Cryopreserved Ovarian Tissues

In recent years,due to environmental deterioration and increasing living pressure,the occurrence of various benign and malignant diseases has been increasing year by year and tends to be younger.With the continuous improvement of screening system and the improvement of diagnosis and treatment level,the five-year survival rate of malignant disease patients has been significantly improved.However,the surgical and chemotherapy measures adopted in the treatment process will cause irreversible damage to the ovarian function of patients,thus leading to ovarian dysfunction,which greatly reduces the quality of life of patients.Female fertility preservation can effectively solve the problem of infertility after malignant disease treatment for women,and cryopreservation of ovarian tissue is one of the important preservation methods.It is currently the only fertility preservation program available for pre-pubertal patients and those who must receive urgent treatment.It shows great potential in preserving ovarian endocrine function.However,ovarian tissue is prone to oxidative stress damage during cryopreservation,which will further affect the survival and development of follicles,thus reducing the quality of tissue.Therefore,in order to effectively freeze-preserve ovarian tissue,it is essential to reduce oxidative stress damage to tissue.To this end,this study proposes a new method of static magnetic field assisted rewarming to enhance the antioxidant capacity of ovarian tissue during cryopreservation.Here,we propose a new method to improve the antioxidant capacity of ovarian tissue during cryopreservation,static magnetic field synergistic thawing.The effects of biological effects of magnetic fields on the basic structure,proliferative and apoptotic properties,post-transplant vascularization,and antioxidant-related biochemical indices of ovarian tissues after thawing and resuscitation were investigated through the application of magnetic fields.The study was conducted as follows: 70 ovarian tissues of SPF-grade female Kunming mice of 6-8 weeks and(weighing about 25g)were randomly divided into seven groups: fresh control group,conventional convective thawing group(control group),and magnetic field treatment group(10Gs,20 Gs,30Gs,40 Gs,50Gs).The fresh group was immediately fixed or tissue homogenized,while the control and magnetic field treated groups were routinely vitrified and then the tissues were thawed according to the treatment ways.After fixed sections of each group,follicle morphology was observed by hematoxylin-eosin staining,collagen fiber content was observed using Sirius red staining,and proliferation and apoptosis were detected by immunofluorescence.Transmission electron microscopy was used to observe the microstructure of granulosa cells.The ovarian tissues grafted in vivo for 10 days,follicles and microvasculature were observed by hematoxylin-eosin staining and further observation of angiogenesis was used immunofluorescence of CD31.Immunohistochemistry of GDF-9 was detected to observe the developmental potential of the tissue.Results from the study showed that exposure to oxidative stress following freeze-thaw resuscitation treatment caused significant damage to the follicles,including a decrease in collagen fiber content,severe vacuolization of the granulosa cell cytoplasm,and reduced micro angiogenesis post-transplantation.However,samples treated with SMF showed improved follicular structural integrity,increased proliferation,and decreased apoptosis,thus providing a basis for the theory of vitrification of ovarian tissues.Further analysis of granulosa cell microstructure and energy production within the tissue was conducted to explain the mechanism of action of the magnetic field.It was concluded that static magnetic field treatment of suitable intensity could effectively boost the antioxidant capacity of the whole ovarian tissue,leading to increased proliferation of germ cells and increased vascular regeneration,which in turn could help to sustain follicular development following transplantation.The present study empirically confirms the feasibility of cryopreservation of ovarian tissue using a synergistic application of magnetic fields.This innovative approach can open up new possibilities for preserving female fertility and may have significant implications for the field of assisted reproduction.