Search Results (58)

Ovarian tissue cryopreservation (OTC) has emerged as the only viable fertility preservation strategy for prepubertal girls and adolescent cancer patients facing gonadotoxic treatments. While OTC has transitioned from an experimental procedure to an established clinical practice, the functional longevity of transplanted grafts remains limited by massive follicle depletion. This review synthesizes recent technological advances in OTC for female children, with a particular focus on the underlying molecular mechanisms and innovative protective strategies. We systematically evaluate pre-cryopreservation assessments, surgical harvesting techniques such as medulla-sparing biopsies, and the comparative efficacy of slow freezing versus vitrification in preserving stromal and follicular integrity. Central to this discussion are the molecular drivers of post-transplantation injury, including ischemia–reperfusion-induced oxidative stress and the iatrogenic over-activation of the PI3K/Akt/mTOR signaling pathway, which leads to follicular “burnout.” Furthermore, we explore targeted pharmacological interventions, such as the dual-drug application of VEGFA and rapamycin, alongside emerging bioengineering frontiers including decellularized extracellular matrix scaffolds and 3D-printed bioprosthetic ovaries. Clinical outcomes are also summarized, highlighting high rates of endocrine recovery (~95%) and promising live birth rates (~28%), predominantly through natural conception. By integrating deep molecular insights with advanced tissue engineering, this review provides a comprehensive framework for optimizing long-term fertility restoration and improving the quality of survivorship for young female cancer survivors. Full article

Background/Objectives: Breast cancer is the most common malignancy in young women, many of whom face fertility impairment due to gonadotoxic treatments and prolonged endocrine therapy. Ovarian tissue cryopreservation (OTC) has emerged as an alternative fertility preservation (FP) strategy, particularly when controlled ovarian stimulation is not feasible. This study aimed to evaluate the role of OTC in breast cancer patients, with the aim of clarifying its current clinical role and future perspectives within fertility preservation counselling for this population. Methods: A structured SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis was conducted based on the current literature, addressing clinical efficacy, safety, and applicability of OTC in breast cancer patients. Results: Key strengths of OTC include the absence of delay in cancer treatment and the potential to restore both endocrine and reproductive function. However, limitations include the need for surgery, the theoretical risk of reintroducing malignant cells, and variable, less predictable reproductive outcomes compared with gamete-based strategies. Opportunities lie in advances in cryopreservation, transplantation techniques, and integration with in vitro maturation. Major threats include limited data in breast cancer-specific populations, challenges in BRCA mutation carriers, and low utilization rates affecting cost-effectiveness and healthcare sustainability. Conclusions: OTC represents a valuable complementary FP option for selected breast cancer patients, particularly in urgent settings. Despite promising outcomes, its use should remain individualized within multidisciplinary counseling, considering patient-specific oncological and reproductive factors, while further research is needed to clarify long-term safety and efficacy. Full article

Background: Although ovarian cryopreservation is an essential strategy for fertility preservation, ischemia–reperfusion injury and oxidative stress can significantly compromise graft viability after transplantation. Melatonin is a potent antioxidant capable of modulating redox homeostasis and tissue repair; however, its effects on the ovarian microenvironment after cryopreservation are not fully understood. Objective: To investigate whether melatonin supplementation during ovarian cryopreservation enhances GPx1/2-mediated antioxidant defense, preserves follicular integrity, and modulates the angiogenic balance (assessed via VEGF-A expression) after autologous ovarian transplantation in rats. Methods: Twenty-four Wistar rats were ovariectomized and divided into control (standard cryopreservation) and melatonin-treated (0.1 μM melatonin) groups. Ovaries were cryopreserved, thawed, and autotransplanted. After 30 days, the grafts were analyzed for GPx1/2 expression (immunohistochemistry), VEGF-A levels (ELISA), biochemical markers, and follicular integrity (histomorphometry) Results: The melatonin treatment significantly increased GPx1/2 expression in the corpus luteum (p = 0.002), theca interna (p = 0.007), and interstitium (p = 0.012), and reduced the number of degenerated follicles (p = 0.03). Although absolute VEGF-A levels did not differ between groups, melatonin-treated animals showed higher VEGF/FSH ratios (p = 0.0007) and VEGF/LH (p = 0.0494) ratios. Positive correlations were observed between GPx1/2 expression and VEGF-A expression. Conclusions: Melatonin increases antioxidant defenses in cryopreserved ovarian grafts through the upregulation of GPx1/2 and preservation of follicular morphology. Instead of directly increasing VEGF-A levels, melatonin appears to modulate angiogenic signaling, contributing to a more stable microenvironment for ovarian graft survival. Full article

Ovarian tissue cryopreservation is the primary fertility preservation strategy for prepubertal girls and patients requiring urgent gonadotoxic therapy. However, the risk of reintroducing malignant cells has prompted the development of safer alternatives, including follicle isolation followed by three-dimensional scaffold encapsulation for transplantation. Fibrin is a promising biomaterial for bioengineered ovary construction, although its ability to support early human follicle maintenance remains unclear. Follicles isolated from cryopreserved ovarian tissues of six patients were encapsulated within fibrin scaffolds of graded concentrations (high, medium, low). After 7 days of in vitro culture, follicle survival and diameter change were quantified. A total of 282 follicles (45.4 ± 10.1 µm) were embedded into fibrin scaffolds. After culture, 237 viable follicles were detected, yielding an overall survival of 84%. Follicle diameter increased to 58.8 ± 12.0 µm. Follicle survival rates were comparable across groups, while mean follicle diameter was 56.3 ± 12.5 µm (high), 61.9 ± 13.4 µm (medium), and 57.4 ± 9.3 µm (low). Follicles cultured in medium-concentration fibrin demonstrated significantly larger diameters compared with both high and low groups (p < 0.05), with no difference between high and low groups. Fibrin-based bioprosthetic ovary scaffolds support short-term in vitro maintenance of isolated human follicles, preserving spherical morphology and granulosa cell layer integrity. Medium-concentration fibrin was associated with greater follicle diameter expansion compared with higher and lower concentrations, indicating that scaffold composition influences early morphometric changes during in vitro follicle culture. Full article

Introduction: Ovarian tissue cryopreservation (OTC) has emerged as an important fertility preservation option for women and girls at risk of treatment-induced ovarian failure. However, long-term data on clinical utilization and reproductive outcomes remain limited. This study provides a 30-year regional overview of OTC practice in Western Sweden. Material and Methods: This retrospective observational cohort study included 60 patients who underwent OTC between 1995 and 2025 within a publicly funded regional fertility preservation program. Data on patient characteristics, indications, surgical approach, cryopreservation techniques, and reproductive outcomes were collected from medical records, tissue bank data, and fertility preservation registries. Results: Malignant diagnoses accounted for 51 cases (85%) of indications, most commonly hematologic malignancies and breast cancer, while 9 patients (15%) had benign conditions requiring gonadotoxic therapy. During follow-up, only one patient (1.7%) underwent ovarian tissue transplantation (OTT), resulting in recovery of endocrine function and a spontaneous twin pregnancy. Overall, 15 women (25%) achieved at least one pregnancy. Of these, 8 (13.3%) occurred spontaneously without prior transplantation, 4 (6.7%) were achieved through oocyte donation, 1 (1.7%) occurred after OTT, and 1 patient (1.7%) had both spontaneous and donor-egg pregnancies. Most women (45/60, 75%) had no documented pregnancy or fertility treatment during follow-up. Conclusions: Over three decades, OTC has been successfully implemented as part of a regional fertility preservation program. However, the low rate of tissue utilization and the predominance of spontaneous pregnancies highlight the gap between tissue preservation and clinical use. These findings underscore the need for improved patient selection, structured long-term follow-up, and individualized risk assessment to optimize the clinical impact of OTC. Full article

Background/Objectives: Hodgkin lymphoma (HL) primarily affects individuals of reproductive age, making gonadal dysfunction after chemotherapy a critical survivorship concern. While fertility preservation options including gamete and gonadal tissue cryopreservation are available before treatment, evidence-based counseling requires regimen-specific risk estimates accounting for patient age and sex. Therefore, a meta-analysis was performed to assess presumed infertility in HL patients, stratified by chemotherapy regimen, age, and sex. Methods: This systematic review and meta-analysis, conducted within the FertiTOX project, included studies published between 2000 and February 2024. Eligible studies reported gonadal function outcomes ≥ 1 year after chemotherapy, excluding patients who received pelvic radiotherapy or stem cell transplantation, or had recurrent disease. Presumed infertility was defined by surrogate markers, including amenorrhea, premature ovarian failure, or abnormal hormonal levels in women, and azoospermia, oligozoospermia, or abnormal hormonal levels in men. Results: Of 2376 screened studies, 50 were included (meta-analysis: 43 studies; 5564 female and 1631 male patients). Overall presumed infertility prevalence was 21% in women (95% CI: 0.14–0.29) and 45% in men (95% CI: 0.29–0.62). The highest prevalence occurred after BEACOPP (women 38%; men 81%), while ABVD was associated with the lowest (6% each in women and men). Childhood/adolescent HL treatment resulted in lower prevalence in women (8%) but remained high in men (67%). Conclusions: Fertility risk depends on regimen, age, and sex, requiring tailored counseling. For female children/adolescents and all patients receiving ABVD, post-treatment fertility evaluation and treatment may suffice. However, pre-treatment fertility preservation is strongly recommended for male adolescents and patients receiving other regimens. Full article

With increasing life expectancy driven by rapid biomedical science advancement, reproductive longevity has become a key concept in women’s health. Preventing reproductive senescence is important not only to extend fertility potential but also to preserve endocrine health, enhance quality of life, and promote healthy aging. The end of ovarian function and fertility is symbolized by menopause, as the most eminent index of reproductive aging. Hormone replacement therapy (HRT) remains the mainstay for managing menopausal symptoms. However, as the use of HRT is often limited, there is a need for safe and effective alternatives. This narrative review summarizes current and emerging approaches targeting different stages of reproductive aging. Both hormonal and non-hormonal therapies for vasomotor and genitourinary symptoms are discussed alongside developing fertility preservation techniques, including oocyte vitrification, ovarian tissue cryopreservation, in vitro follicle maturation, and artificial ovary engineering. Furthermore, evolving and experimental ovarian regenerative strategies, such as stem cell transplantation, intraovarian platelet-rich plasma (PRP) injections, antioxidants, metabolic modulators, telomerase activators, and stem cell-derived extracellular vesicles, offer new prospects for delaying or reversing ovarian aging. Overall, personalized regenerative strategies and innovative solutions may reshape the future of women’s reproductive health and longevity. Full article

The cryopreservation and transplantation of germline stem cells (GSCs) have become the key to conserving fish genetic resources and safeguarding species diversity. This study aimed to investigate the effects of post-mortem temperature and time on the preservation of oogonial stem cells (OSCs) in the marine fish Paralichthys olivaceus. OSCs remained viable after fish death, and they remained viable and could be cultured after storage at 19 °C for 15 h and at 4 °C for 24 h. Combined transcriptomic and metabolomic analysis was used to identify the pathways leading to OSC death. Several genes were differentially expressed in the ovarian tissue post-mortem, with the most enriched pathways being ferroptosis, fatty acid metabolism/biosynthesis, glutathione metabolism, citric acid cycle (TCA cycle), and arachidonic acid metabolism signaling pathways. Genes related to ferroptosis, such as vdac2, p53, and slc7a11, as well as metabolites such as adrenic acid and arachidic acid, can serve as reliable biomarkers for evaluating the viability of post-mortem OSCs. These findings provide valuable insights and theoretical support for the effective use of post-mortem GSCs and enhance strategies for germplasm resource conservation in fish. Full article

Cryopreservation and transplantation of intact ovaries offer a promising approach to fertility restoration in cancer patients. However, ischemia–reperfusion injury following transplantation significantly impairs graft function. This study aimed to evaluate the protective effects of melatonin and elucidate its underlying mechanisms of action, including antioxidant and anti-inflammatory properties. Intact ovaries from 8 to 12-week-old LEWIS rats were cryopreserved and subsequently transplanted. Melatonin (25 mg/kg and 50 mg/kg) was administered daily from day 1 to day 4 postoperatively. Estrous cycle recovery and ovarian histology were examined, along with measurements of hormone concentrations, antioxidant activity, and inflammatory mediators. The oxidative stress response, particularly the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response elements (ARE) signaling pathway—including Nrf2, Kelch-like ECH-associated protein 1 (Keap1), and sMafg—was investigated to elucidate melatonin’s protective mechanisms. The roles of melatonin receptors and Nrf2 were investigated using specific receptor antagonists (Luzindole, 4P-PDOT) and an inhibitor (ML385) to confirm the involvement of the MT1/Nrf2/ARE pathway. As a result, rats treated with high-dose melatonin (50 mg/kg) exhibited accelerated estrous cycle recovery, reduced follicular loss, improved serum hormone levels, enhanced antioxidant capacity in serum and ovarian tissue, and decreased levels of inflammatory cytokines. Furthermore, melatonin exerted its antioxidant and anti-inflammatory effects through activation of the Nrf2/ARE signaling pathway via the MT1 receptor. These protective effects were abolished by the inhibition of either Nrf2 or MT1 receptor. In conclusion, these findings demonstrate that melatonin mitigates oxidative stress and inflammatory damage in intact transplanted ovaries through the MT1/Nrf2/ARE signaling axis, thereby preserving ovarian function post-transplantation. Full article

Background: An artificial ovary has emerged as a novel alternative approach to prevent the reintroduction of cancerous cells after ovarian tissue autotransplantation. This study evaluates the ability of decellularized Wharton’s jelly (dWJ) to facilitate human ovarian follicle growth in a xenotransplantation model. Materials and Methods: Two transplanted groups were established; one consisted of a decellularized Wharton’s jelly/alginate (dWJ/Alg) composite, and an alginate (Alg) group was used as the control group. Each artificial ovary received approximately 20 partially isolated viable human ovarian follicles, subsequently undergoing xenotransplantation into ovariectomized, non-immunodeficient NMRI mice. Grafts were extracted at 1, 2, 4, or 5 weeks for comprehensive histological and immunohistochemical evaluations. Additionally, mouse blood serum was collected for hormonal analysis. Results: H&E staining confirmed granulosa cell proliferation and follicle growth in dWJ/Alg after 1 week of grafting. While human ovarian-like structures and cell proliferation were visible in other grafts, follicles were not observed. Conversely, immunohistochemical staining for Vimentin, Ki67, and CD45 confirmed the presence of human cells, proliferative cells, and inflammatory cells, respectively. However, hormonal assays revealed no significant difference in estrogen or progesterone levels between the experimental groups. Conclusions: It seems that Wharton’s jelly/alginate hydrogel can be used as an artificial niche for simulating the ovarian environment, effectively supporting the growth of xenotransplants of isolated human follicles. Full article

Low-grade-serous ovarian carcinomas (LGSOC) are rare tumors characterized by a high recurrence rate and limited treatment options. Most LGSOC are estrogen receptor (ER)-positive and demonstrate alterations in the RAS/MAPK pathway. Avutometinib is a dual RAF/MEK clamp, whereas defactinib and VS-4718 are focal adhesion kinase (FAK) inhibitors. Fulvestrant is an ER antagonist/degrader. We assessed the preclinical efficacy of fulvestrant, avutometinib + VS-4718 (FAKi), and the triple combination in a chemotherapy/aromatase inhibitor-resistant LGSOC patient-derived tumor xenograft (PDX) model. Tissue obtained from a LGSOC patient wild-type for KRAS/NRAS/BRAF mutations in progression after chemotherapy/anastrozole was transplanted into female CB17/lcrHsd-Prkdc/SCID mice (PDX-OVA(K)250). The animals were treated with either saline/control, fulvestrant, avutometinib/FAKi, or the triple combination of avutometinib/FAKi/fulvestrant. Avutometinib and FAKi were given five-days on and two-days off through oral gavage. Fulvestrant was administered subcutaneously weekly. Mechanistic studies were performed ex vivo using Western blot assays. Animals treated with the triple combination demonstrated stronger tumor growth inhibition compared to all the other experimental groups including control/saline (p < 0.001), single-agent fulvestrant (p = 0.04 from day eight and onwards), and avutometinib/FAKi (p = 0.02 from day 18). Median survival for mice treated with saline/control was 29 days while mice in all other experimental groups were alive at day 60 (p < 0.0001). Treatment was well tolerated across all experimental treatments. By Western blot, exposure of OVA(K)250 to the triple combination demonstrated a decrease in phosphorylated MEK (p-MEK) and p-ERK levels. The addition of fulvestrant to avutometinib/FAKi is well tolerated in vivo and enhances the antitumor activity of avutometinib/FAKi in a LGSOC-PDX model with acquired resistance to chemotherapy/aromatase inhibitors. These results support the clinical evaluation of avutometinib/defactinib in combination with fulvestrant or an aromatase inhibitor in patients with recurrent LGSOC. Full article

Orthotopic transplantation of ovarian tissue at one day of age is a promising solution for preserving female genetic material in avian species; using sterile recipients can ensure that all offspring are donor-derived. This study focuses on the suitability of the Mulard duck as a sterile recipient for Pekin duck donors and provides an investigation of the hormonal background. Firstly, native Pekin ovarian tissue was grafted into Mulard duck recipients, resulting in a 40% adhesion rate and follicular development in 50% of the adhered grafts. Secondly, the transplantation of cryopreserved ovarian tissue resulted in a 66% adhesion rate, with 33% of the adhered grafts showing follicular development. Ovulation occurred in 16% of the recipients with adhered grafts, but the eggs did not move into the oviduct. Estrogen levels were elevated in the recipients with adherence but were lower than in the control Pekin group, while progesterone levels remained unchanged. Consequently, recipients received buserelin acetate, a GnRH analogue, to stimulate follicular and oviductal activity. In this group, graft adhesion occurred in 31% of animals, and primordial follicle development in 25%. The hormonal levels of the recipients with adhered ovaries were elevated, but the GnRH analogue treatment did not affect the ovulation process. We conclude that while the Mulard duck shows potential as a sterile recipient in ovarian transplantation, several questions remain unanswered regarding the adequacy of follicular maturation and ovulation. Full article

Background/Objective: Thrombosis is the leading cause of graft failure and immediate hysterectomy following uterus transplantation (UTx). Currently, there is no standardized method for real-time assessment of UTx graft perfusion. This feasibility study aims to evaluate the utility of a near-infrared spectroscopy (NIRS) probe for non-invasive monitoring of local cervical tissue oxygenation (StO₂) during UTx. As proof-of-concept for the NIRS device, cervical StO₂ was also measured during non-donor hysterectomy and bilateral salpingo-oophorectomy to establish its capacity to reflect perfusion changes corresponding to vascular ligation. Methods: The ViOptix T. Ox Tissue Oximeter NIRS probe was attached to four uterine cervices during hysterectomy procedures and three separate donor cervices during UTx. Real-time StO₂ measurements were recorded at critical surgical steps: baseline, ovarian vessel ligation, contralateral ovarian vessel ligation, uterine vessel ligation, contralateral uterine vessel ligation, and colpotomy for hysterectomy; donor internal iliac vein anastomosis to recipient external iliac vein, donor internal iliac artery anastomosis to recipient external iliac artery, contralateral donor internal iliac vein anastomosis to recipient external iliac vein, contralateral donor internal iliac artery anastomosis to recipient external iliac artery, and donor and recipient vagina anastomosis for UTx. Results: During hysterectomy, average StO₂ levels sequentially decreased: 70.2% (baseline), 56.7% (ovarian vessel ligation), 62.1% (contralateral ovarian vessel ligation), 50.5% (uterine vessel ligation), 35.8% (contralateral uterine vessel ligation), and 8.5% (colpotomy). Conversely, during UTx, StO₂ progressive increased with each anastomosis: 8.9% (internal iliac vein- external iliac vein), 27.9% (internal iliac artery-external iliac artery), 56.9% (contralateral internal iliac vein-contralateral external iliac vein), 65.9% (contralateral internal iliac artery-contralateral external iliac artery), and 65.2% (vaginal anastomosis). Conclusions: The inverse correlation between StO₂ and vascular ligation during hysterectomy and the progressive rise in StO₂ during UTx suggests that cervical tissue oximetry may serve as a non-invasive modality for monitoring uterine graft perfusion. Further studies are warranted to determine whether these devices complement current assessments of uterine graft viability and salvage thrombosed grafts. Full article

The cryopreservation of ovarian tissues from fish has recently been carried out for several endangered and commercially valuable species. However, previous studies in this context have focused on the cryopreservation of immature ovaries—mainly through slow freezing and vitrification—which requires specialized freezing equipment or higher cryoprotectant concentrations to keep cell viability. Therefore, the aim of this study was to explore a convenient, rapid, efficient and less toxic method for the cryopreservation of ovaries at the stage of vitellogenesis from yellow drum (Nibea albiflora), an economically important marine fish. The ovaries at the stage of vitellogenesis were isolated and cut into blocks of approximately 1 cm³, then cryopreserved with 15% propylene glycol (PG), fetal bovine serum (FBS) and 0.2 M trehalose as cryoprotectants. Finally, the samples were treated using three different freezing procedures, including a −80 °C refrigerator, liquid nitrogen, and their combination. After 7 days, the tissues were thawed and digested, and the cell survival rates and gene expression levels were detected using cell viability assay kits and qRT-PCR, respectively. The results of the viability assay showed that the procedure of ovarian tissue storage at −80 °C in a refrigerator for 1 h, followed by transfer to liquid nitrogen, resulted in the highest cell survival rate (>90%). Furthermore, the germ cells at various phases were of normal size; presented a full, smooth surface and regular shape; and did not show any signs of cell rupture, atrophy, depression, granulation or cavitation. Furthermore, the qRT-PCR results revealed that genes related to reproductive development, such as vasa, foxl2, zp3 and gsdf, were all down-regulated under the optimal protocol, while the expression of the nanos2 gene (which is specifically distributed in oogonia) maintained a higher level, similar to that in the control group. This indicated that the viability of germ stem cells (oogonia) was not weakened after freezing and that oogonia could be isolated from the cryopreserved ovaries for germ cell transplantation. The present study successfully establishes an optimal cryopreservation protocol for ovarian tissues from Nibea albiflora, providing reference for the preservation of ovaries at the stage of vitellogenesis from other species. Full article

Ovarian tissue cryopreservation is increasingly recognized as an effective fertility preservation option for cancer patients undergoing gonadotoxic therapies. After cancer treatment, transplantation of frozen–thawed ovarian tissue can restore both fertility and endocrine function. However, the threat of reintroducing malignant cells limits its application in patients with a high risk of ovarian metastasis. To eliminate potential cancer cells in grafts, a promising strategy involves isolating follicles from cryopreserved ovarian tissue and encapsulating them within biocompatible scaffolds to construct transplantable bioprosthetic ovaries. Here, we review the construction of bioprosthetic ovaries designed to mimic natural ovarian architecture, and further discuss the challenges in bioprosthetic ovary bioengineering along with potential strategies to address these issues. Full article