Enhanced spinal cord regeneration by gelatin/alginate hydrogel scaffolds containing human endometrial stem cells and curcumin-loaded PLGA nanoparticles in rat.

Spinal cord injury (SCI) is a serious problem with a high prevalence worldwide. The weak capability of the spinal cord for regeneration in association with upregulation of inflammatory factors is two key obstacles against a full SCI repair. Curcumin is a natural substance with anti-inflammatory and neuroprotective effects. Here, we have used a combined strategy using stem cells and hybrid hydrogel scaffolds loaded with curcumin for SCI repair. Curcumin-loaded PLGA nanoparticles were prepared, characterized, and encapsulated into gelatin/alginate hydrogel scaffolds, which were then seeded by human endometrial stem cells (hEnSCs). The resulting construct was studied using in vitro and in vivo experiments on rat models. DLS, SEM, Zeta potential, and FTIR data confirmed the successful addition of curcumin to PLGA nanoparticles. SEM analyses indicated the successful addition of curcumin-loaded nanoparticles into the gelatin/alginate scaffold, as well as the adherence of the seeded EnSCs. Based on the results, the prepared constructs not only allowed the controlled release of curcumin but also could support the survival and growth of hEnSCs. Based on the results of BBB and histological experiments, the highest BBB score was related to the combined strategy, consistent with histological outcomes, in which our hEnSC-seeded gelatin/alginate scaffold containing curcumin-loaded nanoparticles led to improved structures of the white and gray matters in the SCI site, being indicative of the superior nerve fiber regeneration, compared to other studied groups. These results indicate the efficiency of the proposed method for SCI repair and broaden the scope for subsequent studies on spinal cord regeneration.

Bridging potential of Taurine-loading PCL conduits transplanted with hEnSCs on resected sciatic nerves.

Reconstruction of nerve conduits is a promising method for functional improvement in peripheral nerve repair. Besides choosing of a suitable polymer for conduit construction, adding factors such as Taurine improve a more advantageous microenvironment for defect nerve regeneration. Showing several major biological properties of Taurine, for example, regulation of the osmotic pressure, modulation of neurogenesis, and calcium hemostasis, makes it an appropriate option for repairing of defected nerves. To this, we examined repairing effects of Taurine-loading PCL conduits cultured with human endothelial stem cells (hEnSCs) on resected sciatic nerves. PCL/Taurine/Cell conduits transplanted to a 10-mm sciatic nerve gap. Forty-two wistar rats were randomly divided to seven groups: (1) Normal group, (2) Negative control (NC), (3) Positive control (nerve Autograft group), (4) PCL conduits group (PCL), (5) Taurine loaded PCL conduits group (PCL/Taurine), (6) hEnSCs cultured on the PCL conduits (PCL/Cell), (7) hEnSCs cultured on the PCL/Taurine conduits (PCL/Taurine/Cell). Functional recovery of motor and sensory nerves, the action potential of exciting muscle and motor distal latency has seen in PCL/Taurine/Cell conduits. Histological studies showed also remarkable nerve regeneration and obvious bridging has seen in this group. In conclusion, PCL/Taurine/Cell conduits showing suitable mechanical properties and biocompatibility may improve sciatic nerve regeneration.

Simultaneous impact of atorvastatin and mesenchymal stem cells for glioblastoma multiform suppression in rat glioblastoma multiform model.

Glioblastoma multiform (GBM) is known as an aggressive glial neoplasm. Recently incorporation of mesenchymal stem cells with anti-tumor drugs have been used due to lack of immunological responses and their easy accessibility. In this study, we have investigated the anti-proliferative and apoptotic activity of atorvastatin (Ator) in combination of mesenchymal stem cells (MSCs) on GBM cells in vitro and in vivo. The MSCs isolated from rats and characterized for their multi-potency features. The anti-proliferative and migration inhibition of Ator and MSCs were evaluated by MTT and scratch migration assays. The annexin/PI percentage and cell cycle arrest of treated C6 cells were evaluated until 72 h incubation. The animal model was established via injection of C6 cells in the brain of rats and subsequent injection of Ator each 3 days and single injection of MSCs until 12 days. The growth rate, migrational phenotype and cell cycle progression of C6 cells decreased and inhibited by the interplay of different factors in the presence of Ator and MSCs. The effect of Ator and MSCs on animal models displayed a significant reduction in tumor size and weight. Furthermore, histopathology evaluation proved low hypercellularity and mitosis index as well as mild invasive tumor cells for perivascular cuffing without pseudopalisading necrosis and small delicate vessels in Ator + MSCs condition. In summary, Ator and MSCs delivery to GBM model provides an effective strategy for targeted therapy of brain tumor.

Fibrin hydrogel as a scaffold for differentiation of induced pluripotent stem cells into oligodendrocytes.

The importance of tissue engineering has been established as a promising approach in treating neurodegenerative diseases. The purpose of the current study is to determine the effect of fibrin hydrogel on the differentiation of iPSC into oligodendrocyte. For this purpose, iPSCs transduced by miR-338 expressing lentiviruses. They were treated with basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF)-AA. The process was traced by a 6-day treatment in a mitogen-free medium. At the end of the process, multipolar preoligodendrocytes appeared. In comparison to tissue culture plate (TCP), MTT assay demonstrated a significant increase in the viability of cells cultured in fibrin hydrogel. SEM analysis showed cells with elongated morphology and intertwined intercellular interactions. An immunofluorescent assay confirmed the expression of oligodendrocyte markers Olig2 and O4. In comparison to TCP, real-time PCR data indicated a significant increase in the expression of some markers such as Olig2, MBP, Sox10, and PDGFRα on cells encapsulated in fibrin hydrogel. Overall, the results suggest that fibrin hydrogel improves viability of cells and promotes the differentiation of iPSCs into preoligodendrocytes. Hence, it can be used as an appropriate option in the tissue engineering in order to treat neurodegenerative diseases. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:192-200, 2020.

A novel polycaprolactone/carbon nanofiber composite as a conductive neural guidance channel: an in vitro and in vivo study.

The current study aimed to investigate the potential of carbon nanofibers to promote peripheral nerve regeneration. The carbon nanofiber-imbedded scaffolds were produced from polycaprolactone and carbon nanofibers using thermally induced phase separation method. Electrospinning technique was utilized to fabricate polycaprolactone/collagen nanofibrous sheets. The incorporation of carbon nanofibers into polycaprolactone's matrix significantly reduced its electrical resistance from 4.3 × 109 ± 0.34 × 109 Ω to 8.7 × 104 ± 1.2 × 104 Ω. Further in vitro studies showed that polycaprolactone/carbon nanofiber scaffolds had the porosity of 82.9 ± 3.7% and degradation rate of 1.84 ± 0.37% after 30 days and 3.58 ± 0.39% after 60 days. The fabricated scaffolds were favorable for PC-12 cells attachment and proliferation. Neural guidance channels were produced from the polycaprolactone/carbon nanofiber composites using water jet cutter machine then incorporated with PCL/collagen nanofibrous sheets. The composites were implanted into severed rat sciatic nerve. After 12 weeks, the results of histopathological examinations and functional analysis proved that conductive conduit out-performed the non-conductive type and induced no toxicity or immunogenic reactions, suggesting its potential applicability to treat peripheral nerve damage in the clinic.

Derivation of preoligodendrocytes from human-induced pluripotent stem cells through overexpression of microRNA 338.

MicroRNAs (miRNAs) control gene expression at the posttranscriptional level and have a critical role in many biological processes such as oligodendrocyte differentiation. Recent studies have shown that microRNA 338 (miR-338) is overexpressed during the oligodendrocyte development process in the central nervous system; this finding indicates a potentially important role for miR-338 in oligodendrocyte development. To evaluate this assumption, we studied the effect of miR-338 overexpression on promoting the differentiation of oligodendrocyte progenitor cells (OPCs), derived from human-induced pluripotent stem cells (hiPSC), into preoligodendrocyte. hiPSCs were differentiated into OPCs after treating for 16 days with basic fibroblast growth factor (BFGF), epidermal growth factor (FGF), and platelet-derived growth factor (PDGF)-AA. Bipolar OPCs appeared and the expression of OPC-related markers, including Nestin, Olig2, Sox10, PDGFRα, and A2B5 was confirmed by real-time polymerase chain reaction (PCR) and immunofluorescence. Then, OPCs were transduced by miR-338 expressing lentivirus or were treated with triiodothyronine (T3) for 6 days. Data obtained from real-time PCR and immunofluorescence experiment indicated that preoligodendrocyte markers such as Sox10, O4, and MBP were expressed at higher levels in transduced cells with miR-338 in comparison with the T3 group. So, the overexpression of miR-338 in iPSC-derived OPCs can promote their differentiation into preoligodendrocyte which can be used in cell therapy of myelin-related diseases.

The Anti-Angiogenic Effect of Atorvastatin in Glioblastoma Spheroids Tumor Cultured in Fibrin Gel: in 3D in Vitro Model

Purpose: Glioblastoma multiform (GBM) is the most aggressive glial neoplasm. Researchers have exploited the fact that GBMs are highly vascularized tumors. Anti-angiogenic strategies including those targeting VEGF pathway have been emerged for treatment of GBM. Previously, we reported the anti-inflammatory effect of atorvastatin on GBM cells. In this study, we investigated the anti-angiogenesis and apoptotic activity of atorvastatin on GBM cells. Methods: Different concentrations of atorvastatin (1, 5, 10µM) were used on engineered three-dimensional (3D) human tumor models using glioma spheroids and Human Umbilical Vein Endothelial cells (HUVECs) in fibrin gel as tumor models. To reach for these aims, angiogenesis as tube-like structures sprouting of HUVECs were observed after 24 hour treatment with different concentrations of atorvastatin into the 3-D fibrin matrix and we focused on it by angiogenesis antibody array. After 48 hours exposing with different concentrations of atorvastatin, cell migration of HUVECs were investigated. After 24 and 48 hours exposing with different concentrations of atorvastatin VEGF, CD31, caspase-3 and Bcl-2 genes expression by real time PCR were assayed. Results: The results showed that atorvastatin has potent anti-angiogenic effect and apoptosis inducing effect against glioma spheroids. Atorvastatin down-regulated the expression of VEGF, CD31 and Bcl-2, and induced the expression of caspase-3 especially at 10µM concentration. These effects are dose dependent. Conclusion: These results suggest that this biomimetic model with fibrin may provide a vastly applicable 3D culture system to study the effect of anti-cancer drugs such as atorvastatin on tumor malignancy in vitro and in vivo and atorvastatin could be used as agent for glioblastoma treatment.

Horseradish peroxidase-catalyzed hydrogelation for biomedical applications.

Hydrogels catalyzed by horseradish peroxidase (HRP) serve as an efficient and effective platform for biomedical applications due to their mild reaction conditions for cells, fast and adjustable gelation rate in physiological conditions, and an abundance of substrates as water-soluble biocompatible polymers. In this review, we highlight the tunable characteristics and use of the HRP-catalyzed hydrogels and provide a brief overview of various substrates employed in the HRP system for different biomedical applications of the resultant hydrogels. In addition, we discuss and summarize the biocompatibility, possible functionalization, and biofabrication process. Finally, the future prospective of the HRP crosslinking system is highlighted with biomedical applications.

In vivo assessment of a nanofibrous silk tube as nerve guide for sciatic nerve regeneration.

A nanofibrous silk nerve conduit has been evaluated for its efficiency based on the promotion of peripheral nerve regeneration in rats. The designed tubes with or without Schwann cells were implanted into a 10 mm gap in the sciatic nerves of the rats. Four months after the surgery, the regenerated nerves were monitored and evaluated by macroscopic assessments and histology. The results demonstrated that the nanofibrous grafts, especially in the presence of Schwann cells, enabled reconstruction of the rat sciatic nerve trunk with a restoration of nerve continuity and formation of nerve fibres with myelination. Histological data demonstrated the presence of Schwann and glial cells in regenerated nerves. This study strongly supports the feasibility of using artificial nerve grafts for peripheral nerve regeneration by bridging large defects in a rat model.

Anti-inflammatory Effects of Atorvastatin in Human Glioblastoma Spheroids Cultured in a Three-dimensional Model: Possible Relevance to Glioblastoma Treatment.

Glioblastoma multiform (GBM) is a primary malignant brain tumor with a few therapeutic targets available for it. The interaction between the immune system and glioma is an important factor that could lead to novel therapeutic approaches to fight glioma. In this study, we investigated in vitro anti-inflammatory and apoptotic activity of atorvastatin in different concentrations 1, 5, and 10 µM on glioma spheroid cells cultured in a three-dimensional model in fibrin gel that indicate the complex in vivo microenvironment better than a simple two-dimensional cell culture. A mechanistic insight into the role of IL-17RA, TRAF3IP2, and apoptotic genes in progression of glioma could provide an important way for therapy of malignant tumors with manipulation of this inflammatory axis. To reach for these aims, after 24 and 48 h exposure with different concentrations of atorvastatin, caspase-8, caspase-3, Bcl-2, TRAF3IP2, and IL-17RA gene expression were assayed. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and cell cycle assay were used for evaluating the cell apoptosis and proliferation. The results showed that atorvastatin has anti-inflammatory and apoptotic effects against glioma spheroids. Atorvastatin induced the expression of caspase-3 and caspase-8 and downregulated the expression of Bcl-2, TRAF3IP2, and IL-17RA especially at 10 µM concentration. These effects are dose dependent. The most likely mechanisms are the inhibition of inflammation by IL-17RA interaction with TRAF3IP2 and NF-κB signaling pathway. Finally, these results suggest that atorvastatin could be used as an anti-cancer agent for glioblastoma treatment.

Impact of climate variability on the occurrence of cutaneous leishmaniasis in Khuzestan Province, southwestern Iran.

Leishmaniasis, one of the most important parasitic diseases worldwide, is frequently cited with respect to health risks related to climate change. The current variability of the climate may have different impacts on the transmission of cutaneous leishmaniasis (CL) depending on the various Leishmania species. The number and distribution of CL cases in Khuzestan Province, Southwestern Iran was analysed over the 2010-2014 period with regard to temperature, humidity, rainfall, sunshine hours, evaporation and wind-related climate issues. During the study period, there were 4672 recorded clinical cases of CL, the incidence of which was found to fall into three types of areas, such as high, intermediate and low-level endemic areas. Compared to the intermediate and low-endemic areas, the hyper-endemic areas showed significantly variable meteorological data with regard to rainy days, maximum/minimum temperature and humidity. Decreased temperatures in the eastern part of this province were found to promote the disease towards its centre. We conclude that the meteorological variables and incidence data of CL indicate that the number of rainy days, maximum and minimum temperatures and relative humidity are significant variables that can predict CL incidence. Indeed, the substantial climatic variability occurring during the recent 5-year period (2010-2014) in Khuzestan Province could be the main reason for the change in epidemiology and transmission of CL.

The Role of Stem Cells in the Treatment of Cerebral Palsy: a Review.

Cerebral palsy (CP) is a neuromuscular disease due to injury in the infant's brain. The CP disorder causes many neurologic dysfunctions in the patient. Various treatment methods have been used for the management of CP disorder. However, there has been no absolute cure for this condition. Furthermore, some of the procedures which are currently used for relief of symptoms in CP cause discomfort or side effects in the patient. Recently, stem cell therapy has attracted a huge interest as a new therapeutic method for treatment of CP. Several investigations in animal and human with CP have demonstrated positive potential of stem cell transplantation for the treatment of CP disorder. The ultimate goal of this therapeutic method is to harness the regenerative capacity of the stem cells causing a formation of new tissues to replace the damaged tissue. During the recent years, there have been many investigations on stem cell therapy. However, there are still many unclear issues regarding this method and high effort is needed to create a technology as a perfect treatment. This review will discuss the scientific background of stem cell therapy for cerebral palsy including evidences from current clinical trials.

Apoptotic effect of atorvastatin in glioblastoma spheroids tumor cultured in fibrin gel.

OBJECTIVE: Glioblastoma multiform (GBM) is one of the most common and highly aggressive primary brain tumors that thought to be of glial cells origin. The new available therapy for glioblastoma is based on better understanding of molecular malignant progression in this tumor. It is better to identify key molecular targets stimulating signaling pathways that lead to initiation of apoptosis for treatment of glioblastoma. Tumorigenesis broadly is controlled by tumor microenvironment and design of best biomimetic culture systems dependency on these conditions allow for in vitro and in vivo tumor modeling for studies of cancer cells behavior to drugs. We engineered three-dimensional (3D) human tumor models using U87 glioma cells in fibrin gel that mimic microenvironmental feature of glioblastoma in vivo. In this study, atorvastatin was used as a kind of statins for induction of apoptosis, and inhibition of migration and invasion in glioma cells. METHODS: To reach for these aims, 3D model of glioma in fibrin gel was used with different concentrations of atorvastatin (1, 5, 10µM) to assay apoptotic genes expression by real time PCR and Tunel assay. After 24 and 48h exposing with different concentrations of atorvastatin, cell migration and invasion of tumor cells were investigated. RESULTS: The results showed atorvastatin induced apoptosis of glioma spheroids dose- dependently. The most likely mechanisms are the induction of apoptosis by caspase-8- caspase-3 signaling pathway. The invasion and migration of U87 spheroid cells decreased after 48h especially with 10µM concentration of atorvastatin. CONCLUSION: Finally these results suggest that this biomimetic model with fibrin may provide a vastly applicable 3D culture system to study the effect of anti-cancer drugs such as atrovastatin on tumor malignancy in vitro and in vivo and atorvastatin could be used as anticancer agent for glioblastoma treatment.

In vitro evaluation of human endometrial stem cell-derived osteoblast-like cells' behavior on gelatin/collagen/bioglass nanofibers' scaffolds.

New biomimetic nanocomposite scaffold was prepared by the combination of nanofibrilar bioglass containing copper ion as the inorganic phase and gelatin/collagen as the organic phase of bone tissue. In this study for fabrication of the scaffold, freeze drying and electrospinning methods were used, and genipin was used as the cross-linking agent for increasing the mechanical properties of the scaffold. The growth and viability of human endometrial stem cell-derived osteoblast-like cells were investigated on this biomimetic scaffold. Cellular biocompatibility assays illustrated that this scaffold has more viabilities and osteoblast growths in comparison with two-dimensional culture. Copper ion increased growth of the osteoblasts on nanocomposite scaffold containing nanofibrous bioglass. Thus, the results obtained from this study indicate that the prepared scaffold is suitable for osteoblast growth and attachment; thus, potentially, this nanocomposite scaffold is an appropriate scaffold for bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2210-2219, 2016.

Differentiation of Human Endometrial Stem Cells into Schwann Cells in Fibrin Hydrogel as 3D Culture.

Human endometrial stem cells (hEnSCs) are a new source of adult multipotent stem cells with the ability of differentiation into many cell lineages. Many stem cell sources are desirable for differentiation into Schwann cells. Schwann-like cells derived from hEnSCs may be one of the ideal alternative cell sources for Schwann cell generation. In this study, for differentiation of hEnSCs into Schwann cells, hEnSCs were induced with RA/FSK/PDGF-AA/HRG as an induction medium for 14 days. The cells were cultured in a tissue culture plate (TCP) and fibrin gel matrix. The viability of cultured cells in the fibrin gel and TCP was analyzed with 3-[4,5-dimethyl-2-thia-zolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay for 7 days. The attachment of cells was analyzed with SEM and DAPI staining. The expression of S100 and P75 as Schwann cell markers was evaluated by immunocytochemistry and quantitative real-time PCR (RT-PCR). The evaluation of the MTT assay and gene expression showed that the survival rate and differentiation of hEnSCs into Schwann cells in the fibrin gel were better than those in the TCP group. These results suggest that human EnSCs can be differentiated into Schwann cells in the fibrin gel better than in the TCP, and the fibrin gel might provide a suitable three-dimensional (3D) scaffold for clinical applications for cell therapy of the nervous system.