Micro-RNA-incorporated electrospun nanofibers improve osteogenic differentiation of human-induced pluripotent stem cells.

Smart scaffolds have a great role in the damaged tissue reconstruction. The aim of this study was developing a scaffold that in addition to its fiber's topography has also content of micro-RNAs (miRNAs), which play a regulatory role during osteogenesis. In this study, we inserted two important miRNAs, including miR-22 and miR-126 in the electrospun polycaprolactone (PCL) nanofibers and after scaffold characterization, osteoinductivity of the fabricated nanofibers was investigated by evaluating of the osteogenic differentiation potential of induced pluripotent stem cells (iPSCs) when grown on miRNAs-incorporated PCL nanofibers (PCL-miR) and empty PCL. MiRNAs incorporation had no effect on the fibers size and morphology, cell attachment, and protein adsorption, although viability and proliferation rate of the human iPSCs were increased after a week in PCL-miR compared to the empty PCL. The results obtained from alkaline phosphatase activity, calcium content, bone-related genes, and proteins expression assays demonstrated that the highest osteogenic markers were observed in iPSCs grown on the PCL-miR compared to the cells cultured on PCL and culture plate. According to the results, miR-incorporated PCL nanofibers could be considered as a promising potential tissue-engineered construct for the treatment of patients with bone lesions and defects.

Application of a novel bioreactor for in vivo engineering of pancreas tissue.

Type 1 diabetes is characterized by autoimmune destruction of pancreatic cells. Organ transplantation is an acceptable treatment for native organ failure. However, it is associated with several problems due to a number of reasons, such as the lack of appropriate donors and immunosuppression. In our present study, a novel model is presented for in vivo recellularization of acellular pancreas by implanting between the host pancreas and the adjacent omental flap. In this study, the pancreases were harvested and cannulated via the common bile duct and then, the scaffolds were acellularized by a detergent-based protocol. After that, the abdomens of 35 rats were opened and the spleen was extracted with the adjacent omentum, and placed outside the abdomen. The acellularized scaffold was stretched over the host pancreas and the omentum was wrapped around it to make a sandwich-like structure, which was then fixed with Chromic Sutures 6-0 and marked with Prolene 4-0 on four sides. All samples were biopsied at 14, 30, 60, 90, and 120 days post-transplantation. The result showed marked recellularization of acellularized pancreas with visible neovascularization and neoß-cells with minimal inflammatory response. This study provides a new approach to produces a normal-like pancreas by allograft transplantation for pancreas tissue engineering. We observed that in vivo transplantation of acellularized pancreas can promote recellularization, proliferation, and differentiation by blood circulation. These findings support that in vivo studies can contribute to finding faster solutions for the treatment of diabetes.