تمایز سلول

In recent decades with the advent of nanotechnology, use of nanoparticles has been increased due to increased bioavailability, improved targeted treatment, and reduced toxicity. Selenium is a trace essential element in bodies of humans and animals. This element is found in the structure of numerous enzymes playing various roles in the body of organisms. Under different conditions, several effects have been reported for selenium nanoparticles, the main objective of this study was to evaluate different researches related to using selenium nanoparticles as anti-cancer, stem cell differentiation, wound healing, and dis-infection agent, also nutrition and reproduction performances.

In this study, we present a summary of studies on the effects of selenium nanoparticles in various conditions, including differentiation, anti-cancer, anti-infective and wound healing effects, also nutritional and reproductive performances.

Different forms of selenium have been used in various studies. However, in most studies, selenium nanoparticles show less toxicity than its salt forms (Sodium Selenate, Sodium Selenite, Selenium Dioxide and Selenous Acid). Positive effects have been observed in inhibiting the proliferation of cancer cells and wound infection, improving nutritional and reproduction performances.

It seems that due to the lower toxicity and greater bio-availability of selenium nanoparticles, it can be used instead of its salt forms.

Endometrial stem cells (EnSCs) were identified for the first time in 2004. These cells are capable of extensive self-renewal and have the potency to differentiate into chondrocyte, osteocyte, adipocyte, neuron and oligodendrocyte. PI3K/Akt signaling has been implicated in multiple cellular and organ functions, including differentiation, survival and cell death and its inhibition leads to cell differentiation. The purpose of this study was to investigate the differentiation of endometrial stem cells into neural cells by inhibition of PI3K/Akt pathway using small molecule Ly294002.
Endometrial tissues were treated enzymatically and segregated cells were cultured in DMEM/F12 with 10% FBS. The flow cytometry analysis was perfomed for CD105, CD90, CD146, CD31 and CD34 at the third passage. Then the neurogenic differentiation was evaluated at the third passage, 21 days after induction with differentiation media. Immunocytochemistry and Real-time PCR were performed to investigate the expression of specific neural stem cells markers.
The flow cytometry analysis showed that EnSCs were positive for CD90, CD105 and CD146 and negative for CD31 and CD34. Immunocytochemistry showed that the expression of nestin, NF and Chat neuronal markers in the cells treated with small molecule Ly294002. Real-time PCR also indicated expression of NF and Chat neuronal markers at the mRNA level.
According to the findings of this study it can be concluded that the EnSCs have neural differentiation potency in the suitable differentiation milieu. Ly294002 small molecules by inhibiting PI3K / Akt pathway possibly can prevent cell proliferation and induce cell differentiation

Human mesenchymal stem cells (hMSCs) have shown a great potential in the field of regenerative medicine as well as vascular tissue engineering. Mechanical properties of the cell substrate provides an environment that influences physiological activity of cells such as proliferation, differentiation and cell cytoskeleton developments and consequently modulates functionality of in vitro engineered cells. hMSCs were cultured under two groups of control and growth factor-induced differentiation within two types of substrates with different stiffness. We used Micropipette aspiration technique to evaluate mechanical behavior of cultured cells (effective Young’s modulus (E) and creep compliance value) during their differentiation into smooth muscle cells phenotype. hMSC with growth factor-induced differentiation showed significant decrease in E value in relation to both substrates in compare to control group, within 2 days of cell culture, whereas the creep compliance of these cells sharply increased. Consequently, by increasing the cultivation time to 4 to 6 days, the E values of induced-differentiation cells significantly increased in compare to control samples, with a decrease in the creep compliance of these cells. Furthermore, the state of increase or decrease in creep compliance was depended on substrate stiffness in which the cells were seeded on. Cells cultured on soft substrates showed high tendency for preserving their viscoelastic properties. Our results provides groundwork for stem cell-based tissue engineering in order to optimize culture conditions due to effective usage of external physical cues as well as substrate properties as the regulatory mechanisms of differentiation to functional target cells.