چكيده به لاتين
The topography of the cell culture substrate is a proven factor affecting the differentiation of stem cells. Several studies have been conducted on stem cell differentiation using the cell imprinting method, in which the footprint of the target cells has been employed as the substrate surface topography suggesting that topographical features alone have the capacity to stimulate cell behaviour and lineage spesification. The purpose of this study is to investigate the effect of micro and nano topography of the culture substrate on the chondrogenic differentiation of stem cells. Through the imprinting of the chondrocyte, all these topographies are transmitted on the surface of the PDMS. Therefore, to answer the question whether the microtopography is the reason of stem cell differentiation or nanotopography, after microscopic examination of the chondrocyte surface and its surface profile, silicone wafers with the dimensions of the chondrocytes were designed and developed by photolithography. In fact, the features of these wafers only simulate the spherical morphology of chondrocytes, not the nanotopography of the membrane. By examining the behavior of stem cell differentiation on the substrate containing the pattern of these wafers, it was observed that stem cells did not express collagen type II. Therefore, it can be concluded that the spherical pattern of chondrocytes is not the reason of chondrogenic differentiation of stem cells.
In order to confirm the claim that the nanoscale topography on the substrate is the reason of stem cells differentiation, we used the chondrosarcoma cell line (SW1353), which is fibroblast like and expresses collagen type II. Cell imprinting was performed and the behavior of chondrogenic differentiation of stem cells was evaluated on substrates containing the pattern of these cells. The results of the antibody staining confirmed our claim, and the stem cells expressed collagen type II after 14 days. Finally, it was concluded by this study that in the cell imprinting method, the nanotopography on the chondrocytes surface transferred onto substrate after the molding by PDMS, is the reason of stem cells differentiation toward the chondrocytes.
