Intra-abdominal transplantation of PLGA/PCL/M13 phage electrospun scaffold induces self-assembly of lymphoid tissue-like structure.

Lymphoid organs are the main structural components of the immune system. In the current research, the mixture of poly lactic-co-glycolic acid (PLGA), polycaprolactone (PCL), and M13 phage or its RGD-modified form was used in the construction of a fibrillar scaffold using the electrospinning method. The constructs were transplanted intra-abdominally and examined for the formation of lymphoid-like tissues at different time intervals. The confocal and scanning electron microscopy demonstrate that M13 phage-containing scaffolds provide a suitable environment for lymph node-isolated fibroblasts. Morphological analysis demonstrate the formation of lymph node-like tissues in the M13 phage-containing scaffolds after transplantation. Histological analysis confirm both blood and lymph angiogenesis in the implanted construct and migration of inflammatory cells to the M13 phage-containing scaffolds. In addition, flow cytometry and immunohistochemistry analysis showed the homing and compartmentalization of dendritic cells (DCs), B and T lymphocytes within the PLGA/PCL/M13 phage-RGD based scaffolds and similar to what is seen in the mouse lymphoid tissues. It seems that the application of M13 phage could improve the generation of functional lymphoid tissues in the electrospun scaffolds and could be used for lymphoid tissue regeneration.

Combinational administration of mesenchymal stem cell-derived exosomes and metformin reduces inflammatory responses in an in vitro model of insulin resistance in HepG2 cells.

Diabetes is a highly common metabolic disorder in advanced societies. One of the causes of diabetes is insulin resistance, which is associated with a loss of sensitivity to insulin-sensitive cells. Insulin resistance develops in the body of a person prone to diabetes many years before diabetes development. Insulin resistance is associated with complications such as hyperglycemia, hyperlipidemia, and compensatory hyperinsulinemia and causes liver inflammation, which, if left untreated, can lead to cirrhosis, fibrosis, and even liver cancer. Metformin is the first line of treatment for patients with diabetes, which lowers blood sugar and increases insulin sensitivity by inhibiting gluconeogenesis in liver cells. The use of metformin has side effects, including a metallic taste in the mouth, vomiting, nausea, diarrhea, and upset stomach. For this reason, other treatments, along with metformin, are being developed. Considering the anti-inflammatory role of mesenchymal stem cells (MSCs) derived exosomes, their use seems to help improve liver tissue function and prevent damage caused by inflammation. This study investigated the anti-inflammatory effect of Wharton's jelly MSCs derived exosomes in combination with metformin in the HepG2 cells insulin resistance model induced by high glucose. This study showed that MSCs derived exosomes as an anti-inflammatory agent in combination with metformin could increase the therapeutic efficacy of metformin without needing to change metformin doses by decreasing inflammatory cytokines production, including IL-1, IL-6, and TNF-α and apoptosis in HepG2 cells.

Effective combination of hydrostatic pressure and aligned nanofibrous scaffolds on human bladder smooth muscle cells: implication for bladder tissue engineering.

Bladder tissue engineering has been the focus of many studies due to its highly therapeutic potential. In this regard many aspects such as biochemical and biomechanical factors need to be studied extensively. Mechanical stimulations such as hydrostatic pressure and topology of the matrices are critical features which affect the normal functions of cells involved in bladder regeneration. In this study, hydrostatic pressure (10 cm H(2)O) and stretch forces were exerted on human bladder smooth muscle cells (hBSMCs) seeded on aligned nanofibrous polycaprolactone/PLLA scaffolds, and the alterations in gene and protein expressions were studied. The gene transcription patterns for collagen type I, III, IV, elastin, α-SMA, calponin and caldesmon were monitored on days 3 and 5 quantitatively. Changes in the expressions of α-SMA, desmin, collagen type I and III were quantified by Enzyme-linked immuno-sorbent assay. The scaffolds were characterized using scanning electron microscope, contact angle measurement and tensile testing. The positive effect of mechanical forces on the functional improvement of the engineered tissue was supported by translational down-regulation of α-SMA and VWF, up-regulation of desmin and improvement of collagen type III:I ratio. Altogether, our study reveals that proper hydrostatic pressure in combination with appropriate surface stimulation on hBSMCs causes a tissue-specific phenotype that needs to be considered in bladder tissue engineering.

In vitro differentiation of human cord blood-derived unrestricted somatic stem cells into hepatocyte-like cells on poly(epsilon-caprolactone) nanofiber scaffolds.

Tissue engineering of implantable cellular constructs is an emerging cellular therapy for hepatic disease. In this study, we tested the ability of poly(epsilon-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), alpha-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.

Electrospun polyethersolfone nanofibrous membrane as novel platform for protein immobilization in microfluidic systems.

In the present study, the feasibility of electrospun polyethersolfone (PES) nanofibrous membrane as the solid substrate for microfluidic based immunoassays to enhance the density of immobilized antibody on the surface of membrane was assessed. Conversely, the efficacy of antibody immobilization was compared by two different strategies as 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) coupling chemistry and hydrophobic interaction. Compared to conventional immunoassays carried out in plates or gels, microfluidic based immunoassays grant a lot of advantages such as a consumption of little samples and reagents, shorter analysis time, and higher efficiency. Therefore, microfluidic immunoassays can be efficiently used as a point-of-care device in medical diagnosis. Surprisingly, we found the increase of specific surface areas of the microfluidic channels improve density of immobilized proteins and leads to higher signal strength. Anti-staphylococcus enterotoxin B (anti-SEB) was used as an analyte model to demonstrate the utility of our proposed platform. Fluorescent microscopy, Fourier transform infrared spectroscopic (FTIR), gas adsorption, contact angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Uv-Vis spectrophotometer and atomic force microscopy (AFM) techniques were used to assess the efficacy of antibody immobilization on the surface. To understand dominant mechanism of protein immobilization, zeta potential measurement was also carried out and it was found electrostatic attraction play significant role in antibody immobilization running into micro- channels containing through EDC/NHS. Moreover, incorporation of nanofibrous membrane causes significant improvement in the signal detection of microfluidic based immunoassay. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1108-1120, 2018.

Efficient protein immobilization on polyethersolfone electrospun nanofibrous membrane via covalent binding for biosensing applications.

In this paper we introduce novel strategy for antibody immobilization using high surface area electrospun nanofibrous membrane based on ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling chemistry. To present the high performance of proposed biosensors, anti-staphylococcus enterotoxin B (anti-SEB) was used as a model to demonstrate the utility of our proposed system. Polymer solution of polyethersolfone was used to fabricate fine nanofibrous membrane. Moreover, industrial polyvinylidene fluoride membrane and conventional microtiter plate were also used to compare the efficiency of antibody immobilization. Scanning electron microscopy images were taken to study the morphology of the membranes. The surface activation of nanofibrous membrane was done with the help of O2 plasma. PES nanofibrous membrane with carboxyl functional groups for covalent attachment of antibodies were treated by EDC/NHS coupling agent. The quantity of antibody immobilization was measured by enzyme-linked immuno sorbent assay (ELISA) method. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy was performed to confirm the covalent immobilization of antibody on membrane. Atomic force microscopy, scanning electron microscopy and invert fluorescence microscopy were used to analyze the antibody distribution pattern on solid surfaces. Results show that oxygen plasma treatment effectively increased the amount of antibody immobilization through EDC/NHS coupling chemistry. It was found that the use of nanofibrous membrane causes the improved detection signal of ELISA based biosensors in comparison to the standard assay carried out in the 96-well microtiter plate. This method has the potential to improve the ELISA-based biosensor and we believe that this technique can be used in various biosensing methods.

The promotion of stemness and pluripotency following feeder-free culture of embryonic stem cells on collagen-grafted 3-dimensional nanofibrous scaffold.

The components of extracellular matrix (ECM) may substitute for feeder layers that promote the self-renewal pathways in embryonic stem cells. Surface modification of electrospun nanofibrous scaffolds have been studied to closely resemble natural ECMs and support in vitro and in vivo proliferation, pluripotency and differentiation of stem cells. In this study, we analyzed the maintenance of stemness and pluripotency of the mouse embryonic stem cell (mESC) following feeder-free culture on collagen-grafted polyethersulfone (PES-COL) electrospun nanofibrous scaffold. Our results showed that, the mESCs cultured for seven passages on PES-COL scaffolds had a typical undifferentiated morphology, enhanced proliferation, stable diploid normal karyotype, and continued expression of stemness and pluripotency-associated markers, Oct-4, Nanog, SSEA-1, and Alkaline phosphatase (ALP) in comparison with PES scaffolds and gelatin-coated plate. Moreover, these cells retained their in vitro and in vivo pluripotency. Our results indicated the enhanced infiltration and teratoma formation of mESCs in PES-COL. Collagen-grafted polyethersulfone nanofibrous scaffold has potential for feeder-free culture of pluripotent stem cells because of its 3-dimensional structure and bioactivity which enhance pluripotency, proliferation, differentiation, and infiltration of embryonic stem cells.