Differentiation of eye field neuroectoderm from human adipose-derived stem cells by using small-molecules and hADSC-conditioned medium.

Recently, stem-cell therapy as a promising therapeutic alternative is considered to treat retinal degenerative diseases. Here, we used small molecules and concentrated conditioned medium selectively enriched with Amicon filter units from human adipose-derived stem cells (hADSC-CM) containing various neurotrophic factors to induce hADSCs toward eye field neuroectoderm (EFN). For induction of stem cells, hADSC-CM and small molecules CKI-7, SB431542 and LDN193189 as inhibitors of Wnt, Nodal and BMP4 signaling pathways were used, respectively. We found the highest expression of ß-TUB III as a neural marker in the group in which small molecules and conditioned medium were applied simultaneously. Moreover, EFN markers SIX3, PAX6 and RAX had higher expression in the presence of a conditioned medium. However, the superior expression of ENF marker OTX2 was seen in the small molecules group. Our results indicated that neurotrophic factors present in hADSCs-CM could induce hADSCs into EFN cells. Therefore, a more thorough study of these factors and their effects in hADSC-CM might pave the way for cellular and non-cellular therapy in retinal degenerative diseases.

Hanging drop culture enhances differentiation of human adipose-derived stem cells into anterior neuroectodermal cells using small molecules.

Inspired by in vivo developmental process, several studies were conducted to design a protocol for differentiating of mesenchymal stem cells into neural cells in vitro. Human adipose-derived stem cells (hADSCs) as mesenchymal stem cells are a promising source for this purpose. At current study, we applied a defined neural induction medium by using small molecules for direct differentiation of hADSCs into anterior neuroectodermal cells. Anterior neuroectodermal differentiation of hADSCs was performed by hanging drop and monolayer protocols. At these methods, three small molecules were used to suppress the BMP, Nodal, and Wnt signaling pathways in order to obtain anterior neuroectodermal (eye field) cells from hADSCs. After two and three weeks of induction, the differentiated cells with neural morphology expressed anterior neuroectodermal markers such as OTX2, SIX3, ß-TUB III and PAX6. The protein expression of such markers was confirmed by real time, RT-PCR and immunocytochemistry methods According to our data, it seems that the hanging drop method is a proper approach for neuroectodermal induction of hADSCs. Considering wide availability and immunosuppressive properties of hADSCs, these cells may open a way for autologous cell therapy of neurodegenerative disorders.

The evaluation of prepared microgroove pattern by femtosecond laser on alumina-zirconia nano-composite for endosseous dental implant application.

Ceramic dental materials, especially alumina (20 %vol)-yttrium stabilized tetragonal zirconia poly crystal (A-Y-TZP20), have been considered as alternatives to metals for endosseous dental implant application. For increasing the bone-to-implant contact as well as the speed of bone formation, a new surface modification can be effective. The aim of this study was to design microgroove patterns by femtosecond laser on A-Y-TZP20 nano-composite disks for endosseous dental implant application. The phase composition and the morphology of the A-Y-TZP20 nano-composite samples were characterized using X-ray diffraction and Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy techniques. Statistical analysis was submitted to Kolmogorov-Smirnov test and Student's t test for independent variables, with a 5 % significance level. EDAX analysis revealed a significant decrease in the relative content of contaminants like carbon (p < 0.05) in laser surface-treated group as compared to non surface-treated group. X-ray diffraction did not show any change in the crystalline structure induced by laser processing. It was concluded that the femtosecond laser is a clean and safe method for surface modification of A-Y-TZP20.