Extracellular matrix-derived scaffolds in constructing artificial ovaries for ovarian failure: a systematic methodological review

Decellularized extracellular matrix from bovine ovarian tissue maintains the protein composition of the native matrisome

Recent approaches of regenerative reproductive medicine investigate the decellularized extracellular matrix to develop a transplantable engineered ovary (TEO). However, a full proteomic analysis is not usually performed after the decellularization process to evaluate the preservation of the extracellular matrix (ECM). In this study, the ECM of the bovine ovarian cortex was analyzed before and after decellularization using mass spectrometry and bioinformatics. A total of 155 matrisome proteins were identified in the native ECM of the bovine ovarian cortex, with 145 matrisome proteins detected in the decellularized ECM. After decellularization, only 10 matrisome proteins were lost, and notably, none belonged to the category of reproductive biological processes. Histology and histochemistry analyses were employed to assess the general morphology of both native and decellularized ECM, allowing for the identification of the most abundant ECM proteins. Moreover, our study highlighted collagen type VI alpha 3 and heparan sulfate proteoglycan 2 as the most abundant components in the bovine ovarian ECM, mirroring the composition observed in the human ovary. These findings enhance our understanding of the composition of both native and decellularized ECM, with the potential implications for the development of a TEO. SIGNIFICANCE: The significance of the present study lies on the possibility of advancing towards developing a bioengineered ovary, which is the ultimate strategy to regain fertility in women. The results demonstrate that the decellularized extracellular matrix of the bovine ovary maintains the protein composition of the native matrisome, using a recently described decellularization protocol. The decellularized matrix may serve as scaffolding for seeding ovarian stromal cells and follicles to create a bioengineered ovary, and as closer its composition is to the native matrix the better. Also, comparing the bovine ovarian matrisome, which was described for the first time here, with the human ovarian matrisome, we could see a great similarity, suggesting that the bovine ovary decellularized matrix may serve as a model for developing a human bioengineered ovary.

Development of decellularization protocols for female cat reproductive organs

Decellularization is an innovative method to create natural scaffolds by removing all cellular materials while preserving the composition and three-dimensional ultrastructure of the extracellular matrix (ECM). The obtention of decellularized reproductive organs in cats might facilitate the development of assisted reproductive techniques not only in this species but also in other felids. The aim was to compare the efficiency of three decellularization protocols on reproductive organs (ovary, oviduct, and uterine horn) in domestic cats. The decellularization protocol involved 0.1% sodium dodecyl sulfate and 1%Triton X-100. Protocol 1 (P1) entailed 2-cycles of decellularization using these detergents. Protocol 2 (P2) was like P1 but included 3-cycles. Protocol 3 (P3) was similar to P2, with the addition of deoxyribonuclease incubation. Reproductive organs from nine cats were separated into two sides. One side served as the control (non-decellularized organ) while the contralateral side was the treated group (decellularized organ). The treated organs were subdivided into 3 groups (n = 3 per group) for each protocol. Both control and treated samples were analyzed for DNA content, histology (nuclear and ECM (collagen, elastin, and glycosaminoglycans (GAGs)) density), ultrastructure by electron microscopy, and cytotoxicity. The results of the study showed that P3 was the only protocol that displayed no nucleus residue and significantly reduced DNA content in decellularized samples (in all the studied organs) compared to the control (P < 0.05). The ECM content in the ovaries remained similar across all protocols compared with controls (P > 0.05). However, elastic fibers and GAGs decreased in decellularized oviducts (P < 0.05), while collagen levels remained unchanged (P > 0.05). Regarding the uterus, the ECM content decreased in decellularized uterine horns from P3 (P < 0.05). Electron microscopy revealed that the microarchitecture of the decellularized samples was maintained compared to controls. The decellularized tissues, upon being washed for 24 h, showed cytocompatibility following co-incubation with sperm. In conclusion, when comparing different decellularization methods, P3 proved to be the most efficient in removing nuclear material from reproductive organs compared to P1 and P2. P3 demonstrated its success in decellularizing ovarian samples by significantly decreasing DNA content while maintaining ECM components and tissue microarchitecture. However, P3 was less effective in maintaining ECM contents in decellularized oviducts and uterine horns.

An update on oncofertility in prepubertal females

Cancer is a life-threatening event for pediatric patients. Treatment advancements in pediatric cancer have improved prognosis, but some of these treatments have gonadotoxic potential and may affect fertility in different ways. Due to the growing interest of the research community in the life prospects of young cancer survivors, there has been a demand to intersect reproductive medicine and oncology, which is referred to as "oncofertility". There are various fertility preservation options according to gender and pubertal status, and shared decisions must take place at the time of diagnosis. This study aims to provide a critical review of current and emerging strategies for preserving and restoring fertility in prepubertal females, ranging from established methods to experimental approaches that can be offered before, during, and after anticancer therapies. Additionally, the author aims to review how clinicians' awareness of oncofertility options and the latest advancements in this field, timely referral, and proper consultations with patients and their families are vital in addressing their concerns, providing emotional support, and guiding them through the decision-making process, as well as potential barriers that may hinder the fertility preservation process.

Innovative Strategies for Fertility Preservation in Female Cancer Survivors: New Hope from Artificial Ovary Construction and Stem Cell-Derived Neo-Folliculogenesis

Recent advances in anticancer treatment have significantly improved the survival rate of young females; unfortunately, in about one third of cancer survivors the risk of ovarian insufficiency and infertility is still quite relevant. As the possibility of becoming a mother after recovery from a juvenile cancer is an important part of the quality of life, several procedures to preserve fertility have been developed: ovarian surgical transposition, induction of ovarian quiescence by gonadotropin-releasing hormone agonists (GnRH-a) treatment, and oocyte and/or ovarian cortical tissue cryopreservation. Ovarian tissue cryostorage and allografting is a valuable technique that applies even to prepubertal girls; however, some patients cannot benefit from it due to the high risk of reintroducing cancer cells during allograft in cases of ovary-metastasizing neoplasias, such as leukemias or NH lymphomas. Innovative techniques are now under investigation, as in the construction of an artificial ovary made of isolated follicles inserted into an artificial matrix scaffold, and the use of stem cells, including ovarian stem cells (OSCs), to obtain neo-folliculogenesis and the development of fertilizable oocytes from the exhausted ovarian tissue. This review synthesizes and discusses these innovative techniques, which potentially represent interesting strategies in oncofertility programs and a new hope for young female cancer survivors.