Graphene Oxide Negatively Regulates Cell Cycle in Embryonic Fibroblast Cells.

BACKGROUND: Unique properties of graphene and its derivatives make them attractive in the field of nanomedicine. However, the mass application of graphene might lead to side effects, which has not been properly addressed in previous studies, especially with regard to its effect on the cell cycle. METHODS: The effect of two concentrations (100 and 200 µg/mL) of nano- and microsized graphene oxide (nGO and mGO) on apoptosis, cell cycle, and ROS generation was studied. The effect of both sizes on viability and genotoxicity of the embryonic fibroblast cell cycle was evaluated. MTT and flow cytometry were applied to evaluate the effects of graphene oxide (GO) nanosheets on viability of cells. Apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: The results of this study showed that GO disturbed the cell cycle and nGO impaired cell viability by inducing cell apoptosis. Interestingly, both nGO and mGO blocked the cell cycle in the S phase, which is a critical phase of the cell cycle. Upregulation of TP53-gene transcripts was also detected in both nGO- and mGO-treated cells compared to the control, especially at 200 µg/mL. DNA content of the treated cells increased; however, because of DNA degradation, its quality was decreased. CONCLUSION: In conclusion, graphene oxide at both nano- and micro-scale damages cell physiology and increases cell population in the S phase of the cell cycle.

The fate of mesenchymal stem cells is greatly influenced by the surface chemistry of silica nanoparticles in 3D hydrogel-based culture systems.

Polymeric hydrogel-based 3D scaffolds are well-known structures, being used for cultivation and differentiation of stem cells. However, scalable systems that provide a native-like microenvironment with suitable biological and physical properties are still needed. Incorporation of nanomaterials into the polymeric systems is expected to influence the physical properties of the structure but also the stem cells fate. Here, alginate/gelatin hydrogel beads incorporated with mesoporous silica nanoparticles (MSNs) (average diameter 80.9 ±â€¯10 nm) and various surface chemistries were prepared. Human adipose-derived mesenchymal stem cells (hASCs) were subsequently encapsulated into the alginate/gelatin/silica hydrogels. Incorporation of amine- and carboxyl-functionalized MSNs (A-MSNs and C-MSNs) significantly enhances the stability of the hydrogel beads. In addition, the expression levels of Nanog and OCT4 imply that the incorporation of A-MSNs into the alginate/gelatin beads significantly improves the proliferation and the stemness of encapsulated hASCs. Importantly, our findings show that the presence of A-MSNs slightly suppresses in vivo inflammation. In contrast, the results of marker gene expression analyses indicate that cultivation of hASCs in alginate beads incorporated with C-MSNs (10% w/w) leads to a heterogeneously differentiated population of the cells, i.e., osteocytes, chondrocytes, and adipocytes, which is not appropriate for both cell culture and differentiation applications.

Expressional and Bioinformatic Analysis of Bovine Filia/Ecat1/Khdc3l Gene: A Comparison with Ovine Species.

Maternal effect genes have highly impressive effects on pre-implantation development. Filia/Ecat1/Khdc3l is a maternal effect gene found in mouse oocytes and embryos, loss of which causes a 50% decrease in fertility. In the present study, we investigated Filia mRNA expression in bovine oviduct, 30- to 40-day fetus, liver, heart, lung, and oocytes (as a positive control), by RT-PCR and detected it only in oocytes. A 443 bp fragment was amplified only in oocytes and was sequenced as a part of bovine predicted Filia mRNA. We analyzed bovine and ovine Filia N-terminal peptide sequence in PHYRE2, and a KH domain was predicted. Protein alignment using ClustalW indicated a highly identical N-terminal extention between the 2 species. Immunohistochemical analysis using anti-bovine Filia antibody showed the expression of Filia protein in the zone surrounding the nuclear membrane, and in the subcortex of ovine oocytes of primary and antral follicles. However, in the bovine, Filia has been found through the oocyte cytoplasm of antral follicles, and here it is further confirmed in the primary follicles. Our data suggests a difference in Filia expression pattern between cow and sheep, although the sequence is highly conserved.