Three-dimensional decellularized amnion membrane scaffold promotes the efficiency of male germ cells generation from human induced pluripotent stem cells

Advancements in three-dimensional bioprinting for reproductive medicine: a systematic review

Reproductive failure due to age, genetics and disease necessitates innovative solutions. While reproductive tissue transplantation has advanced, ongoing research seeks superior approaches. Biomaterials, bioengineering and additive manufacturing, such as three-dimensional (3D) bioprinting, are harnessed to restore reproductive function. 3D bioprinting uses materials, cells and growth factors to mimic natural tissues, proving popular for tissue engineering, notably in complex scaffold creation with cell distribution. The versatility which is brought to reproductive medicine by 3D bioprinting allows more accurate and on-site applicability to various problems that are encountered in the field. However, in the literature, there is a lack of studies encompassing the valuable applications of 3D bioprinting in reproductive medicine. This systematic review aims to improve understanding, and focuses on applications in several branches of reproductive medicine. Advancements span the restoration of ovarian function, endometrial regeneration, vaginal reconstruction, and male germ cell bioengineering. 3D bioprinting holds untapped potential in reproductive medicine.

DNA fragmentation, antioxidant activity and histological structure of cryopreserved testicular tissue depending on sexual maturity and immunological status

The objective of this work was to determine a relationship between a frequency of DNA fragmentation, a level of antioxidant activity and a preservation of histological structure depending on initial status of fragments of seminiferous tubules of testes (FSTT) of rats at the stages of cryopreservation. FSTT of animals of different ages (immature, mature), as well as animals with changed immunological status (adjuvant arthritis) were cryopreserved. Slow uncontrolled freezing was used in a cryomedium of fibrin gel with 0.7 M glycerol. The results showed that viability, TAS, γGGT and G6PD activities had the highest values in the group of intact immature animals both in fresh FSTT and after exposure to cryomedium or cryopreservation, while the indexes of DNA fragmentation and ROS content had the lowest values. It was found that an increase in the DNA fragmentation rate occurred in parallel with a decrease in the values of antioxidant activity and membrane integrity. The spermatogenenic epithelium after cryopreservation differed between the groups in a relative number of cells with pathologically changed nuclei and the frequency of exfoliation of epithelial cells into the tubule cavity namely, there was a tendency to an increase in the damaging effects in the series, "Immature → Sexually mature → Autoimmune arthritis". The obtained data can be taken into account in the development of low-temperature preservation protocols using cryotechnologies, which will ensure the maintenance of the morphological and functional characteristics of FSTT depending on sexual maturity and immunological status.

Tissue engineering studies in male infertility disorder

Infertility is an important issue among couples worldwide which is caused by a variety of complex diseases. Male infertility is a problem in 7% of all men. In vitro spermatogenesis (IVS) is the experimental approach that has been developed for mimicking seminiferous tubules-like functional structures in vitro. Currently, various researchers are interested in finding and developing a microenvironmental condition or a bioartificial testis applied for fertility restoration via gamete production in vitro. The tissue engineering (TE) has developed new approaches to treat male fertility preservation through development of functional male germ cells. This makes TE a possible future strategy for restoration of male fertility. Although 3D culture systems supply the perception of the effect of cellular interactions in the process of spermatogenesis, formation of a native gradient of autocrine/paracrine factors in 3D culture systems have not been considered. These results collectively suggest that maintaining the microenvironment of testicular cells even in the form of a 3D-culture system is crucial in achieving spermatogenesis ex vivo. It is also possible to engineer the testicular structures using biomaterials to provide a supporting scaffold for somatic and stem cells. The insemination of these cells with GFs is possible for temporally and spatially adjusted release to mimic the microenvironment of the in situ seminiferous epithelium. This review focuses on recent studies and advances in the application of TE strategies to cell-tissue culture on synthetic or natural scaffolds supplemented with growth factors.

Advances of three-dimensional (3D) culture systems for in vitro spermatogenesis

The loss of germ cells and spermatogenic failure in non-obstructive azoospermia are believed to be the main causes of male infertility. Laboratory studies have used in vitro testicular models and different 3-dimensional (3D) culture systems for preservation, proliferation and differentiation of spermatogonial stem cells (SSCs) in recent decades. The establishment of testis-like structures would facilitate the study of drug and toxicity screening, pathological mechanisms and in vitro differentiation of SSCs which resulted in possible treatment of male infertility. The different culture systems using cellular aggregation with self-assembling capability, the use of different natural and synthetic biomaterials and various methods for scaffold fabrication provided a suitable 3D niche for testicular cells development. Recently, 3D culture models have noticeably used in research for their architectural and functional similarities to native microenvironment. In this review article, we briefly investigated the recent 3D culture systems that provided a suitable platform for male fertility preservation through organ culture of testis fragments, proliferation and differentiation of SSCs.

Biomaterials for Testicular Bioengineering: How far have we come and where do we have to go?

Traditional therapeutic interventions aim to restore male fertile potential or preserve sperm viability in severe cases, such as semen cryopreservation, testicular tissue, germ cell transplantation and testicular graft. However, these techniques demonstrate several methodological, clinical, and biological limitations, that impact in their results. In this scenario, reproductive medicine has sought biotechnological alternatives applied for infertility treatment, or to improve gamete preservation and thus increase reproductive rates in vitro and in vivo. One of the main approaches employed is the biomimetic testicular tissue reconstruction, which uses tissue-engineering principles and methodologies. This strategy pursues to mimic the testicular microenvironment, simulating physiological conditions. Such approach allows male gametes maintenance in culture or produce viable grafts that can be transplanted and restore reproductive functions. In this context, the application of several biomaterials have been proposed to be used in artificial biological systems. From synthetic polymers to decellularized matrixes, each biomaterial has advantages and disadvantages regarding its application in cell culture and tissue reconstruction. Therefore, the present review aims to list the progress that has been made and the continued challenges facing testicular regenerative medicine and the preservation of male reproductive capacity, based on the development of tissue bioengineering approaches for testicular tissue microenvironment reconstruction.

Generation of male germ cells in vitro from the stem cells

Infertility has become a serious disease since it affects 10%-15% of couples worldwide, and male infertility contributes to about 50% of the cases. Notably, a significant decrease occurs in the newborn population by 7.82 million in 2020 compared to 2016 in China. As such, it is essential to explore the effective methods of obtaining functional male gametes for restoring male fertility. Stem cells, including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), spermatogonial stem cells (SSCs), and mesenchymal stem cells (MSCs), possess the abilities of both self-renewal and differentiation into germ cells. Significantly, much progress has recently been achieved in the generation of male germ cells in vitro from various kinds of stem cells under the specified conditions, e.g., the coculturing with Sertoli cells, three-dimensional culture system, the addition of growth factors and cytokines, and/or the overexpression of germ cell-related genes. In this review, we address the current advance in the derivation of male germ cells in vitro from stem cells based on the studies of the peers and us, and we highlight the perspectives and potential application of stem cell-derived male gametes in reproductive medicine.

Fish Pluripotent Stem-Like Cell Line Induced by Small-Molecule Compounds From Caudal Fin and its Developmental Potentiality

The technique of induced pluripotent stem cells has significant application value in breeding and preserving the genetic integrity of fish species. However, it is still unclear whether the chemically induced pluripotent stem cells can be induced from non-mammalian cells or not. In this article, we first verify that fibroblasts of fish can be chemically reprogrammed into pluripotent stem cells. These induced pluripotent stem-like cells possess features of colony morphology, expression of pluripotent marker genes, formation of embryoid bodies, teratoma formation, and the potential to differentiate into germ cell-like cells in vitro. Our findings will offer a new way to generate induced pluripotent stem cells in teleost fish and a unique opportunity to breed commercial fish and even save endangered fish species.

The therapeutic potential of adipose tissue-derived mesenchymal stromal cells in the treatment of busulfan-induced azoospermic mice

PURPOSE

The generation of germ cells from mesenchymal stromal cells (MSCs) provides a valuable in vitro platform for infertility modeling. The establishment of these cells is a new approach for assisted reproductive technology (ART) to help infertile patients who lack functional gametes.

METHODS

Human adipose-derived MSCs were isolated and then characterized for multipotency by flow cytometry, differentiation capacity, and cytogenetic assays. These cells were used in a male germ cell differentiation study. The expression of male germ cell markers was evaluated at day 21 of differentiation using an immunofluorescence assay, flow cytometry, and RT-qPCR. Undifferentiated MSCs were used for transplantation in busulfan-induced azoospermic mice.

RESULTS

In this study, MSCs were successfully isolated from human adipose tissues which were positive for cell markers such as CD90, CD105, CD73, and CD29 but negative for CD34 and CD45. The results of flow cytometry, immunocytochemistry, and RT-qPCR analysis at day 21 of differentiation showed that the undifferentiated adipose-derived MSCs are able to differentiate into male germ cells. Additionally, transplantation of undifferentiated MSCs in busulfan-induced azoospermic mice caused spermatogenesis recovery in the majority of seminiferous tubules.

CONCLUSION

In this study, we showed that differentiation of human adipose-derived MSCs into male germ cells is a useful tool for in vitro study of human germ cell development. Our results demonstrated that cell therapy with adipose-derived MSCs could help the repair of pathological changes in testicular seminiferous tubules. Therefore, it may have a clinical application for the treatment of azoospermia in infertile patients.

A comparison between BMP4 and SB4 in inducing germ line gene expression pattern during embryonic stem cells differentiation

Germ cell production from stem cells allows for studying the mechanisms involved in gamete development with the aim of helping infertile couples with the generation of healthy gametes. In this context, improving the protocols for in-vitro germ cell induction from stem cells is very important. Recently, SB4 small molecule has been introduced as a potent agonist for bone morphogenic protein 4 (BMP4). Herein, we investigated whether BMP4, is replaceable by SB4 for having affordable protocol for in vitro germ cell differentiation. We demonstrated that SB4 can induce Blimp1 (as the first gene induced germ line differentiation) expression significantly but at a lower level compared to BMP4. However, Tfap2c (a putative downstream target of Blimp1 during germ cell differentiation) expression level in SB4-induced aggregates was significantly higher than in BMP4-induced aggregates. Moreover, co-presence of both BMP4 and SB4 could increase the expression level of Prdm14, Nnose3 and Stella (Dppa3), and thereby improve establishment of the germ cell fate during in-vitro differentiation of embryonic stem cells. In summary, our data suggest that SB4 could improve germ line gene expression pattern induced by BMP4 during embryonic stem cells in-vitro differentiation.

The effect of aflibercept and arsenic trioxide on the proliferation, migration and apoptosis of oral squamous cell carcinoma in vitro

Aflibercept and arsenic trioxide drugs apply a cytotoxic effect on some human cancer cell lines. However, no more study has followed the effects of both drugs, especially arsenic trioxide, on oral squamous cell carcinoma (OCC). We used three OCC lines as a model to show the effect of these drugs on the genetically complex disease and investigate its targeted therapy. In this study, three human OCC cell lines were used from different patients. We treated cell lines with both medications to detect the effect and relevant molecular basis. First, methyl thiazolyl tetrazolium (MTT) assay was performed to detect the cytotoxicity effect and cell growth. Second, flow cytometry, gene and protein expression were performed to evaluate the anti-angiogenic effect on OCC lines. Next apoptosis was analyzed by flow cytometry. Finally, clonogenesis capacity and cell migration were assessed by colony formation assay and wound healing, respectively. Aflibercept had no cytotoxic effect on the three OCC cell lines but decreased cell growth rate. Arsenic trioxide had a significant cytotoxic effect on three cell lines. Our results demonstrated that both drugs significantly decreased endoglin, VEGFA, and VEGFB expression. In addition, Migration and colony formation assays confirmed that these drugs have significant anti-proliferative and anti-migration effect on oral carcinoma cells. These results revealed that both medications might be a potential drug for the management of oral cancer patients.

Advanced bioengineering of male germ stem cells to preserve fertility

In modern life, several factors such as genetics, exposure to toxins, and aging have resulted in significant levels of male infertility, estimated to be approximately 18% worldwide. In response, substantial progress has been made to improve in vitro fertilization treatments (e.g. microsurgical testicular sperm extraction (m-TESE), intra-cytoplasmic sperm injection (ICSI), and round spermatid injection (ROSI)). Mimicking the structure of testicular natural extracellular matrices (ECM) outside of the body is one clear route toward complete in vitro spermatogenesis and male fertility preservation. Here, a new wave of technological innovations is underway applying regenerative medicine strategies to cell-tissue culture on natural or synthetic scaffolds supplemented with bioactive factors. The emergence of advanced bioengineered systems suggests new hope for male fertility preservation through development of functional male germ cells. To date, few studies aimed at in vitro spermatogenesis have resulted in relevant numbers of mature gametes. However, a substantial body of knowledge on conditions that are required to maintain and mature male germ cells in vitro is now in place. This review focuses on advanced bioengineering methods such as microfluidic systems, bio-fabricated scaffolds, and 3D organ culture applied to the germline for fertility preservation through in vitro spermatogenesis.

Establishment and Preservation of Lymphoblastoid Cell Lines from Fresh and Frozen Whole Blood and Mononuclear Cells

Although blood cells are interesting sources for genome investigations, one of the main problems in obtaining genomic DNA from blood is the restricted amount of DNA. This obstacle can be avoided by generating Epstein-Barr virus (EBV)-induced B cell lines. This study investigates the efficiency of four different methods to generate lymphoblastoid cell lines (LCLs). Blood samples (n = 120) were obtained from donors and categorized into four groups: fresh whole blood, frozen whole blood, fresh peripheral blood mononuclear cells (PBMCs), and frozen PBMCs. The samples were followed by EBV transformation to generate LCLs. Quality control and authentication of the cells were performed using multiplex PCR and short tandem repeat (STR) analyses. Finally, we assessed the success rate and amount of time to establish the cell lines in each group. The results showed that the cells were not contaminated nor were they misidentified or cross-contaminated with other cells. The success rate of LCLs generated from the whole blood groups was lower than the PBMC groups. The freezing procedures did not have any considerable effect on the establishment of lymphoblastoid cells. These established cells have been preserved in the human and animal cell bank of the Iranian Biological Resource Center (IBRC) and are available for researchers. Due to the management and transformation of a substantial number of blood samples, we recommend that researchers freeze PBMCs for further use with high efficiency and time-saving. We suggest that whole fresh blood should be directly transformed when the volume of the blood sample is less than 0.5 ml.