Clinical Applications of Assisted Oocyte Activation in Couples with Various Reproductive Problems: A Systematic Review.

ICSI may face fertilization failure, prompting the use of assisted oocyte activation (AOA) techniques. While AOA is implemented in infertility clinics, its target patients and definitive application remain uncertain. This systematic review adheres to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to assess reproductive outcomes in ICSI-AOA cycles compared to conventional ICSI and evaluate AOA effectiveness in various infertility disorders. A literature search encompassed PubMed, Web of Science, EMBASE, and Scopus databases until December 2023 for relevant English studies. Included studies compared ICSI-AOA with conventional ICSI in couples with prior fertilization failure, utilizing diverse AOA methods. Control groups consisted of sibling oocytes, previous cycles of the same couples, or couples undergoing conventional ICSI. Evaluated outcomes included fertilization, cleavage, embryo quality, implantation, pregnancy, and live birth rates. Article screening and data extraction were performed by two authors, with risk of bias assessed by another investigator. Out of 3088 initially identified articles, 30 studies were included, focusing on fertilization failure (n = 10), female infertility (n = 3), PLCζ defects (n = 4), poor sperm quality (n = 4), Globozoospermia (n = 4), and surgically retrieved sperm (n = 8). Most studies concluded that AOA could overcome fertilization failure, but success rates varied based on sperm-related or oocyte-related factors in ICSI-AOA cycles. Due to differences in patient inclusion criteria and sample sizes, most studies were not sufficiently similar for pooled analysis, limiting robust conclusions. There is insufficient evidence, particularly from randomized controlled trials (RCTs), to determine the efficacy or safety of ICSI-AOA as a treatment strategy. Registration number is PROSPERO, CRD42024551221.

Evaluation puramatrix as a 3D microenvironment for neural differentiation of human breastmilk stem cells.

The extracellular matrix is recognized as an efficient and determining component in the growth, proliferation, and differentiation of cells due to its ability to perceive and respond to environmental signals. Applying three-dimensional scaffolds can create conditions similar to the extracellular matrix and provide an opportunity to investigate cell fate. In this study, we employed the PuraMatrix hydrogel scaffold as an advanced cell culture platform for the neural differentiation of stem cells derived from human breastmilk to design an opportune model for tissue engineering. Isolated stem cells from breastmilk were cultured and differentiated into neural-like cells on PuraMatrix peptide hydrogel and in the two-dimensional system. The compatibility of breastmilk-derived stem cells with PuraMatrix and cell viability was evaluated by scanning electron microscopy and MTT assay, respectively. Induction of differentiation was achieved by exposing cells to the neurogenic medium. After 21 days of the initial differentiation process, the expression levels of glial fibrillary acidic protein (GFAP), microtubule-associated protein (MAP2), ß-tubulin III, and neuronal nuclear antigen (NeuN) were analyzed using the immunostaining technique. The results illustrated a notable expression of MAP2, ß-tubulin-III, and NeuN in the three-dimensional cell culture in comparison to the two-dimensional system, indicating the beneficial effect of PuraMatrix scaffolds in the process of differentiating breastmilk-derived stem cells into neural-like cells. In view of the obtained results, the combination of breastmilk-derived stem cells and PuraMatrix hydrogel scaffold could be an advisable preference for neural tissue regeneration and cell therapy.

Comparative phenotypic characterization of human colostrum and breast milk-derived stem cells.

There is a diverse population of stem cells in human breast milk that can be employed for therapeutic purposes as a reservoir of cells. The current study mainly aimed to determine the nature markers expressing on stem cells. For this aim, the expression of embryonic stem cell markers, as well as the expression of endothelial, mesenchymal, neural, and hematopoietic markers were evaluated by the flow cytometry analysis in fresh colostrum, breast milk, and cultured colostrum samples. The results showed that the embryonic (OCT4, SOX2, HLA-DR), hematopoietic (CD33, CD45, CD117), neural (CD133, Nestin), and mesenchymal (CD44, SCA1) stem cell markers present in colostrum had higher expression in comparison with their counterpart markers in fresh breast milk. The expression markers of stem cells in colostrum following a 2-week culture period were significantly increased compared with their counterpart markers in colostrum before the culture process. In the culture of breastmilk, cells were not observed adherent cells and colonies. Our findings form flow cytometry and cell culture suggest that the lactation stage could be one of the factors influencing the stem cell population and, consequently, the cultivation of breastmilk cells. The present study indicates that colostrum is a tremendous source of stem cells that could be applied in cell-based research.

Histological Study of Bone Marrow and Umbilical Cord Stromal Cell Transplantation in Regenerating Rat Peripheral Nerve.

OBJECTIVE: Bone marrow and umbilical cord stromal cells are multipotential stem cells that have the ability to produce growth factors that play an important role in survival and generation of axons. The goal of this study was to evaluate the effects of the two different mesenchymal stem cells on peripheral nerve regeneration. MATERIALS AND METHODS: In this experimental study, a 10 mm segment of the left sciatic nerve of male Wistar rats (250-300 g) was removed with a silicone tube interposed into this nerve gap. Bone marrow stromal cells (BMSCs) and human umbilical cord stromal cells (HUCSCs) were respectively obtained from rat and human. The cells were sepa- rately cultured and transplanted into the nerve gap. The sciatic nerve regeneration was evaluated by immunohistochemistry, and light and electron microscopy. Moreover, histo- morphology of the gastrocnemius muscle was observed. RESULTS: The nerve regeneration in the BMSCs and HUCSCs groups that had received the stem cells was significantly more favorable than the control group. In addition, the BM- SCs group was significantly more favorable than the HUCSCs group (P<0.05). CONCLUSION: The results of this study suggest that both homograft BMSCs and het- erograft HUCSCs may have the potential to regenerate peripheral nerve injury and transplantation of BMSCs may be more effective than HUCSCs in rat.