Electrospun Polycaprolactone Nanofibers: Current Research and Applications in Biomedical Application.

Unique mechanical properties, miscibility potency, and biodegradability are the three prominent features of polycaprolactone (PCL), making it an attractive biomaterial which commonly applied in regenerative medicine and biomedical engineering. Different strategies developed for fabricating nanofibrous construct, electrospinning is a practical, simple, and efficient technique based on electro-hydrodynamic systems that use an electrified viscous fluid jet drawn by the air toward a collector at a changing electric potential. PCL electrospun-based nanofibrous composites as proper scaffolds are employed in stem cell-related research, particularly in tissue engineering, wound dressing, and systems designed for sending drugs. A compilation of mechanochemical properties and most common biological performance on PCL-based electrospun fibrous structures in biomedical application are included in this study. Therefore, electrospun PCL nanofiber applying has been presented, and after that, current progress and prospects have been discussed. Literature reviews revealed that electrospun PCL nanofibrous composites had gained significant attention in regenerative medicine, and these structures have shown notable development in mechanobiological properties. This evidence is a crucial success for biomedical strategies, especially in regenerative medicine.

Improvement of hepatogenic differentiation of iPS cells on an aligned polyethersulfone compared to random nanofibers.

The application of stem cells holds great promises in cell and tissue transplants. This study was designed to compare the hepatogenic differentiation of iPSCs on aligned PES/COL versus random. Aligned and random PES/COL nanofibrus scaffolds were fabricated by electrospining and their surface modified through plasma treatment and collagen coating. The scaffolds were characterized using scanning electron microscopy (SEM) and ATR-FTIR. Morphology and biochemical activities of the differentiated hepatocyte-like cells (HLCs) were examined after 5 and 20 days of differentiation. Real-Time RT-PCR and ICC showed no significant difference in the mRNA and protein levels of two important definitive endoderm specific markers, including Sox17 and Foxa2 between two scaffolds. However, Real-Time RT-PCR analysis indicated an increase in the expression of Cyp7A1 gene over the period of the differentiation procedure on the aligned nanofibers but there was no difference in other genes such as Albumin and CK19. Moreover, comparison of hepatogenic differentiation evaluated by Albumin production in conditioned media of HLCs differentiated on aligned PES/COL, showed increase expression of these markers after 20 days compared to that of the random nanofibers. Taken together, the results of this study may indicate that aligned PES/COL nanofibrous scaffolds can improve terminal differentiation of HLCs from iPSCs.

Hepatogenic Differentiation of Human Induced Pluripotent Stem cells on Collagen-Coated Polyethersulfone Nanofibers.

Many scientists have been fascinated with induced pluripotent stem cells (iPSCs) for cell replacement therapies. Nanofibrous biocompatible scaffolds have been shown to foster better cell adhesion and improve stem cell differentiation. In the current study, after fabrication using electrospinning technique and surface modifications, the characteristics of polyethersulfone (PES) nanofibers were determined by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyltetrazolium bromide (MTT) assay. Then, the hepatogenic potential of iPSCs was evaluated using real-time reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry (ICC) after culture on collagen-coated polyethersulfone (PES/COL) scaffolds. After scaffolds characterization, analysis of two important definitive endoderm specific markers (Sox17 and Foxa2) using real-time RT-PCR and ICC indicated increase in their mRNA and protein levels after 5 days of hepatogenic induction. In addition, to determine hepatic differentiation of iPSCs cultured on PES/COL, the expression of albumin and α-fetoprotein was evaluated by ICC after 20 days. Real-time RT-PCR analysis showed increased expression of albumin, TAT, cytokeratin 19, and Cyp7A1 genes during the course of differentiation program. Finally, enzyme-linked immunosorbent assay analysis demonstrated an increased expression of albumin in the protein level after 28 days of differentiation. In conclusion, our results demonstrated that PES/COL nanofibrous scaffolds could be a proper substrate to significantly increase the hepatogenic differentiation potential of iPSCs and could also be introduced as a promising candidate for liver tissue engineering applications.

ROR2 Promoter Methylation Change in Osteoblastic Differentiation of Mesenchymal Stem Cells.

OBJECTIVE: Osteoblasts arise from multipotent mesenchymal stem cells (MSCs) present in the bone marrow stroma and undergo further differentiation to osteocytes or bone cells. Many factors such as proteins present in the Wnt signaling pathway affect osteoblast differentiation. ROR2 is an orphan tyrosine kinase receptor that acts as a co-receptor in the non-canonical Wnt signaling pathway. However, ROR2 has been shown to be regulated by both canonical and non-canonical Wnt signaling pathways. ROR2 expression increases during differentiation of MSCs to osteoblasts and then decreases as cells differentiate to osteocytes. On the other hand, research has shown that ROR2 changes MSC fate towards osteoblasts by inducing osteogenic transcription factor OSTERIX. Here we speculated whether ROR2 gene expression regulation during osteoblastogenesis is epigenetically determined. MATERIALS AND METHODS: MSCs from bone marrow were isolated, expanded and characterized in vitro according to standard procedures. ROR2 promoter methylation status was determined using methylation specific PCR in a multipotent state and during differentiation to osteoblasts. RESULTS: We determined that the demethylation process in ROR2 promoter occurs during the differentiation process. The process of demethylation begins at day 8 and continues until 21 days of differentiation. CONCLUSION: This result is in concordance with previous works on the role of ROR2 on osteoblast differentiation, which have shown an upregulation of ROR2 expression during this process.