Tissue engineering of implantable cellular constructs is an emerging cellular therapy for hepatic disease. In this study, we tested the ability of poly(ε-caprolactone) (PCL) nanofiber scaffold to support and maintain hepatic differentiation of human cord blood-derived unrestricted somatic stem cells (USSCs) in vitro. USSCs, self-renewing pluripotent cells, were isolated from human cord blood. The electrospun PCL nanofiber porous scaffold was constructed of uniform, randomly oriented nanofibers. USSCs were seeded onto PCL nanofiber scaffolds, and were induced to differentiate into hepatogenic lineages by culturing with differentiation factors for 6 weeks. RT-PCR analysis of endoderm and hepatic-specific gene expression, immunohistochemical detection of cytokeratin 18 (CK-18), α-fetoprotein, albumin, glycogen storage and indocyanine green uptake confirmed the differentiation of USSCs into endoderm and hepatocyte-like cells. In the present study, we show that hepatocyte-like cells differentiated from USSCs on the PCL nanofiber scaffold can be candidate for tissue engineering and cell therapy of hepatic tissues.

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Controlled delivery of multiple therapeutic agents can be considered as an effective approach in skin tissue engineering. In this study, recombinant human epidermal growth factor (rhEGF) and recombinant human basic fibroblast growth factor (rhbFGF) encapsulated in PLGA microspheres were loaded in hybrid scaffolds of PLGA and PEO. The scaffolds with various formulations were fabricated through electrospinning in order to maintain dual, individual or different release rate of rhEGF and rhbFGF. Morphological, physical and mechanical properties of the scaffold were investigated. The scaffold possessed uniform morphology with an average diameter of 280 nm for PLGA and 760 nm for PEO nanofibers. Furthermore, the mechanical properties of the scaffolds were shown to be akin to those of human skin. Bioactivity of the scaffolds for human skin fibroblasts was evaluated. The HSF acquired significant proliferation and well-spread morphology on the scaffolds particularly in the case of different release rate of rhEGF and rhbFGF which implies the synergistic effect of the growth factors. Additionally, collagen and elastin gene expression was significantly up-regulated in the HSF seeded on the scaffolds in the case of individual delivery of rhEGF and dual delivery of rhEGF and rhbFGF. In conclusion, the prepared scaffolds as a suitable supportive substrate and multiple growth factor delivery system can find extensive utilization in skin tissue engineering.

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.

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