Background and Objective: Poly D,L-lactic-co-glycolic acid (PLGA) is known as biodegradable and biocompatible polymer. These polymers have recently received much attention in tissue engineering. The aim of this study was to investigate the biological behavior of the bone marrow stromal cells (BMSCs) in culturing with PLGA nanofibers coated with poly-L-lysine or gelatin. Materials and Methods: In this study, the electrospinning of PLGA nanofibers was performed with hexafluoro-2-propanol (HFIP) as solvent and coated with gelatin and poly-L-lysine, separately. The properties of polymers were investigated with scanning electron microscopy (SEM) analysis and contact angles were studied. After culturing BMSCs and reaching passage two, cells in the four groups of nanofibers, nanofibers PLGA, PLGA nanofibers coated with poly-L-lysine, and PLGA nanofibers coated with gelatin, were grown. Cell proliferation during the second, fourth and sixth days were examined by Acridin Orange and morphology of the cells seeded on nanofibers were investigated via SEM. Results: The mean diameter of PLGA nanofibers were between 270 - 700 nm. The average contact angles were 107.66° for PLGA, 64.58 for PLGA coated with gelatin and 40.12 for poly-L-lysine-coated PLGA, respectively. The results showed significant reduction in cell proliferation in PLGA nanofibers alone (P <0.05). But this number increased in groups of nanofibers coated with poly-L-lysine and gelatin. Conclusion: Culture of Schwann cells with PLGA nanofibers coated with gelatin and particularly coated with poly-L-lysine provide a biodegradable scaffold associated with Schwann cells.

Background and Objective: Differentiation of mesenchymal stem cells into neurons has great potential in the therapy of damaged nerve tissue. Neural tissue engineering offers tremendous promise to combat the effects of disease, aging and injury in the nervous system. The aim of this study was to investigate the differentiation of adipose derived stem cells to neuron like cells on aligned nanofibrous scaffold.

Materials and Methods: In this study, the surface of aligned polycaprolactone (PCL) nanofibrous scaffolds were modified with O₂ plasma treatment to enhance their hydrophilicity in order to differentiate hADSCs into neuron like cells. The chemical and mechanical characteristics of electrospined aligned PCL fibers were determined using scanning electron microscope (SEM) and the calculation of contact angles. The differentiation of adipose derived stem cells was performed using neuronal inducing factors including bFGF, forskolin and NGF with 1% FBS for 8 days.

Results: Real-time PCR analysis indicated the upregulation of Map2, NSE, and NFM genes and down-regulation of Nestin. Also the expression of neuronal proteins such as MAP2 and βTubullin were confirmed by immunocytochemistry. It was found that the direction of cell elongation and neurite outgrowth on the aligned nanofibrous scaffolds is parallel to the direction of fibers.

Conclusion: The results of the present study proposed that p-PCL is a cost-effective material for differentiation of hADSCs into neuron like cells and could apply in nerve tissue repair.

   Background & Objective: The combination of two or more therapeutic agents and their synergetic impacts can be therapeutically effective against multifactorial diseases, such as diabetic foot ulcers. This study demonstrates the application of a nanofiber-based drug delivery system with a controlled release of the growth factor. Various studies have shown that vascular endothelial growth factor (VEGF) stimulates angiogenesis via the VEGF signaling pathway and graphene oxide (GO) has been reported to possess antibacterial property. Therefore, VEGF and GO are hypothesized to have wound-healing effects when used synergistically.
 Materials & Methods:  In this study, VEGF was purified and verified by western blotting. GO and polycaprolactone (PCL) were prepared by electrospinning and were characterized by scanning electron microscope. Next, VEGF was immobilized by EDC/NHS linker in PCL-GO. Staphylococcus aureus and Escherichia coli were used to evaluate the antibacterial property of GO. Biodegradation and other release properties of the nanofibers were assessed. Moreover, the nanofibers were studied for cell viability and gene expression using human umbilical vein endothelial cells.
 Results:  The re-analysis of the protein-protein interaction network from the GO database confirmed the centrality of the nitric oxide synthase 3 (eNOS) showing its effects on the expression of other proteins. In addition, the PCL-GO nanofiber loaded with VEGF was studied for the expression of the eNOS gene in the VEGF signaling pathway. It was observed that PCL-GO-VEGF led to an increased expression of the eNOS gene in two weeks.
 Conclusion:   Based on the observed antibacterial property and angiogenesis influence, PCL-GO-VEGF can be considered as a candidate to promote diabetic wound healing.