Recent advances in enhances peripheral nerve orientation: the synergy of micro or nano patterns with therapeutic tactics.

Several studies suggest that topographical patterns influence nerve cell fate. Efforts have been made to improve nerve cell functionality through this approach, focusing on therapeutic strategies that enhance nerve cell function and support structures. However, inadequate nerve cell orientation can impede long-term efficiency, affecting nerve tissue repair. Therefore, enhancing neurites/axons directional growth and cell orientation is crucial for better therapeutic outcomes, reducing nerve coiling, and ensuring accurate nerve fiber connections. Conflicting results exist regarding the effects of micro- or nano-patterns on nerve cell migration, directional growth, immunogenic response, and angiogenesis, complicating their clinical use. Nevertheless, advances in lithography, electrospinning, casting, and molding techniques to intentionally control the fate and neuronal cells orientation are being explored to rapidly and sustainably improve nerve tissue efficiency. It appears that this can be accomplished by combining micro- and nano-patterns with nanomaterials, biological gradients, and electrical stimulation. Despite promising outcomes, the unclear mechanism of action, the presence of growth cones in various directions, and the restriction of outcomes to morphological and functional nerve cell markers have presented challenges in utilizing this method. This review seeks to clarify how micro- or nano-patterns affect nerve cell morphology and function, highlighting the potential benefits of cell orientation, especially in combined approaches.

Curcumin-loaded human endometrial stem cells derived exosomes as an effective carrier to suppress alpha-synuclein aggregates in 6OHDA-induced Parkinson's disease mouse model.

Parkinson disease (PD) is considered as one of the most worldwide neurodegenerative disorders. The major reasons associated to neurodegeneration process of PD pathogenesis are oxidative stress. Many studies reported that natural antioxidant molecules, especially, curcumin can suppress inflammatory pathways and preserve dopaminergic neurons damage in PD. Further, the poor pharmacokinetics, instability of chemical structure because of fast hydrolytic degradation at physiologic condition and especially, the presence of the blood brain barrier (BBB) has regarded as a considerable restriction factor for transfer of neurotherapeutic molecules to the brain tissue. The present research aims to the fabrication of nanoformulated curcumin loaded human endometrial stem cells derived exosomes (hEnSCs EXOs-Cur) to study on enhancing curcumin penetration to the brain across BBB and to improve anti- Parkinsonism effects of curcumin against neural death and alpha-synuclein aggregation. hEnSCs EXOs-Cur characterization results demonstrated the accurate size and morphology of formulated curcumin loaded exosomes with a proper stability and sustained release profile. In vivo studies including behavioral, Immunohistochemical and molecular evaluations displayed that novel formulation of hEnSCs EXO-Cur is able to cross BBB, enhance motor uncoordinated movements, suppress the aggregation of αS protein and rescue neuronal cell death through elevation of BCL2 expression level as an anti-apoptotic protein and the expression level reduction of BAX and Caspase 3 as apoptotic markers.

Synergistic inhibitory effect of human umbilical cord matrix mesenchymal stem cells-conditioned medium and atorvastatin on MCF7 cancer cells viability and migration.

Recent studies have demonstrated inhibitory effects of mesenchymal stem cells on breast tumors. Likewise, the emerging interest in statins as anticancer agents is based on their pleiotropic effects. In the present study, we investigated whether atorvastatin and umbilical cord matrix derived mesenchymal stem cells-conditioned medium affect the MCF7 cancer cells viability and interactions. We measured the viability of MCF7 cancer cells by MTT assay, flow cytometry, and quantitative real-time PCR. Two-dimensional culture and hanging drop aggregation assay illustrated the morphological changes. We traced the MCF7 migration via scratch-wound healing test and trans-well assay. The results showed the inhibition of cancer cell viability in all treated groups compared to the control group. The effect of atorvastatin and conditioned medium combination was significantly more than each substance separately. The morphological changes indicated apoptosis in treated cells. The annexin V/PI flow cytometry especially in the combination-treated group displayed decreasing in DNA synthesis and cell cycle arrest in G1 and G2/M phases. As well, the mRNA expressions of caspases 3, 8, 9, and Bcl-2 genes were along with extrinsic and intrinsic apoptosis pathways. Conditioned medium disrupted the connections between cancer cells, so the spheroids in three-dimensional configuration lost their order and dispersed. The migration of treated cells across the wound area and trans-well diminished, particularly by the conditioned medium and atorvastatin combination. There fore, the synergistic anti-proliferative and anti-motility effect of atorvastatin along with human umbilical cord mesenchymal stem cells-derived conditioned medium on MCF7 breast cancer cells have been proved. The results might lead the development of novel adjuvant anticancer therapeutics based on targeting or modifying the extracellular matrix to increase chemotherapy results or to prevent metastatic colonization. Schematic representation of "Synergistic Inhibitory Effect of Human Umbilical Cord Matrix Mesenchymal Stem Cells-Conditioned Medium and Atorvastatin on MCF7 Cancer Cells Viablity and Migration" by: Dr. Reyhaneh Abolghasemi, Dr. Somayeh Ebrahimi-barough, Proffesor. Jafar Ai.

Defining the role of 17ß-estradiol in human endometrial stem cells differentiation into neuron-like cells.

Human endometrial stem cells (hEnSCs) that can be differentiated into various neural cell types have been regarded as a suitable cell population for neural tissue engineering and regenerative medicine. Considering different interactions between hormones, growth factors, and other factors in the neural system, several differentiation protocols have been proposed to direct hEnSCs towards specific neural cells. The 17ß-estradiol plays important roles in the processes of development, maturation, and function of nervous system. In the present research, the impact of 17ß-estradiol (estrogen, E2) on the neural differentiation of hEnSCs was examined for the first time, based on the expression levels of neural genes and proteins. In this regard, hEnSCs were differentiated into neuron-like cells after exposure to retinoic acid (RA), epidermal growth factor (EGF), and also fibroblast growth factor-2 (FGF2) in the absence or presence of 17ß-estradiol. The majority of cells showed a multipolar morphology. In all groups, the expression levels of nestin, Tuj-1 and NF-H (neurofilament heavy polypeptide) (as neural-specific markers) increased during 14 days. According to the outcomes of immunofluorescence (IF) and real-time PCR analyses, the neuron-specific markers were more expressed in the estrogen-treated groups, in comparison with the estrogen-free ones. These findings suggest that 17ß-estradiol along with other growth factors can stimulate and upregulate the expression of neural markers during the neuronal differentiation of hEnSCs. Moreover, our findings confirm that hEnSCs can be an appropriate cell source for cell therapy of neurodegenerative diseases and neural tissue engineering.

Application of Platelet Rich Fibrin in Tissue Engineering: Focus on Bone Regeneration.

Bone tissue engineering (BTE) is a strategy for reconstructing bone lesions, which is rapidly developing in response to higher demands for bone repairing. Recently, this method, along with the emergence of functionally graded, biocompatible and biodegradable materials, has been expanded. Moreover, scaffolds with chemical, physical and external patterns have induced bone regeneration. However, the maintenance of healthy bone and its regeneration in the human body needs a series of complex and accurate processes. Hence, many studies have been accompanied for reconstructing bone by using blood-derived biomaterials, especially platelet-rich fabricates. The most important reason for using platelet-rich formulations in bone regeneration is based on releasing growth factors from alpha granules in platelets, which can induce osteogenesis. Moreover, the presence of fibrin nano-fiber structures as a constituent can provide a good substrate for cell attachments. This study attempts to review the history, structure, and biology of platelet-rich fibrin (PRF) as well as in vitro, pre-clinical, and clinical studies on the use of PRF for bone regeneration.

miR-219 overexpressing oligodendrocyte progenitor cells for treating compression spinal cord injury.

Oligodendrocyte progenitor cells (OPCs) transplantation has been considered a promising treatment for spinal cord injury, according to previous studies. Recent research shed light on the importance of microRNA 219 (miR-219) in oligodendrocyte development, so here miR-219-overexpressing OPCs (miR-219 OPCs) were transplanted in animal models of spinal cord injury to evaluate the impact of miR-219 on oligodendrocyte differentiation and functional recovery in vivo. Our findings demonstrate that transplanted cells were distributed in the tissue sections and contributed to reducing the size of cavity in the injury site. Interestingly, miR-219 promoted OPC differentiation into mature oligodendrocyte expressing MBP in vivo whereas in absence of miR-219, less number of cells differentiated into mature oligodendrocytes. An eight week evaluation using the Basso Beattie Bresnahan (BBB) locomotor test confirmed improvement in functional recovery of hind limbs. Overall, this study demonstrated that miR-219 promoted differentiation and maturation of OPCs after transplantation and can be used in cell therapy of spinal cord injury.

MicroRNA-4731-5p delivered by AD-mesenchymal stem cells induces cell cycle arrest and apoptosis in glioblastoma.

Glioblastoma multiforme (GBM) exhibits the most malignant brain tumor with very poor prognosis. MicroRNAs (miRNAs) are regulatory factors that can downregulate the expression of multiple genes. Several miRNAs acting as tumor-suppressor genes have been identified so far. The delivery of miRNA by mesenchymal stem cell (MSC) due to their ability to specifically target tumors is a new, hopeful therapeutic approach for glioblastoma. The objective of our study is the investigation of the effect of lentivirus-mediated microRNA-4731 (miR-4731) genetic manipulated adipose-derived (AD)-MSC on GBM. The downregulation of miR-4731 in human GBM tumor was detected using the GEO dataset. To evaluate the function of miR-4731, we overexpressed miR-4731 using lentiviral vectors in U-87 and U-251 GBM cell lines. The effects of miR-4731 on cell proliferation and cell cycle of glioma cells were analyzed by wound test and flow-cytometry assay. miR-4731 inhibited the proliferation of GBM cancer cells. Coculturing was used to study the antiproliferative effect of miR-4731-AD-MSCs on GBM cell lines. Direct and indirect coculture of GBM cell lines with miR-4731-AD-MSCs induced cell cycle arrest and apoptosis. Our findings suggest that AD-MSCs expressing miR-4731 have favorable antitumor characteristics and should be further explored in future glioma therapy.

Microtubule stabilizer epothilone B as a motor neuron differentiation agent for human endometrial stem cells.

Microtubule-stabilizing agents (MSAs), until now, have primarily been considered for their anti-proliferative effects in the setting of cancer. However, recent studies have revealed that one particular MSA, epothilone B (EpoB), can promote axonal regeneration after traumatic spinal cord injuries (SCI) even in the presence of inhibitor molecules such as neurite outgrowth inhibitor-A (Nogo-A). On the basis of the importance of having an efficient motor neuron (MN) differentiation protocol for stem cell therapy and the attention of MSAs for SCI treatment, our study investigated the effect of EpoB on human endometrial stem cells (hEnSCs) differentiation into MN-like cells. hEnSCs were isolated and characterized by flow cytometry. The hEnSC cell viability was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. To mimic the in vivo inhibitory environment, hEnSCs were also differentiated in the presence of Nogo-A. After 15 days of differentiation, the expressions of MN-markers were evaluated by real-time reverse-transcriptase polymerase chain reaction and immunofluorescence. According to the MTT assay results, three doses (1, 5, and 10 nM) of EpoB were selected to evaluate their effect on MN-differentiation. All selected doses can increase the efficacy of hEnSCs differentiation into MN-like cells. In particular, the 10 nM EpoB dosage was shown to increase the axon elongation, cell alignment, and upregulation of these MN-markers compared with other doses. EpoB can improve MN differentiation from hEnSC and potentially provide a unique route for neuronal replacement in the setting of SCI.

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.

Cell-Based Therapy for Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is a devastating neurodegenerative disease characterized by the degeneration of lower motor neurons in the spinal cord, leading to progressive paralysis and early death in the severe cases. SMA is primarily caused by the mutations in the gene of SMN (survival motor neuron). More research has focused on the development of SMN-targeted replacement therapy for SMA. The first US Food and Drug Administration (FDA)-approved modified antisense oligonucleotide (nusinersen) to treat SMA is to reverse intronic splicing silencer of SMN to produce fully functional SMN2. Recently, stem cell transplantation has shown the potential to repair the injured tissue and differentiate into neurons to rescue the phenotypes of SMA in animal models. In this chapter, we first review the clinical, genetic, and pathogenic mechanisms of SMA. Then, we discuss current pharmacological treatments and point out the therapeutic efficacy of stem cell transplantation and future directions and priorities for SMA.

Embryonic stem cells differentiated into neuron-like cells using SB431542 small molecule on nanofibrous PLA/CS/Wax scaffold.

Electrospun nanofibrous scaffolds show huge potential to improve the neurological outcome in central nervous system disorders. In this study, we cultured mouse embryonic stem cells (mESCs) on an electrospun nanofibrous polylactic acid/Chitosan/Wax (PLA/CS/Wax) scaffold and surveyed the attachment, behavior, and differentiation of mESCs into neural cells. Differentiation in neural-like cells (NLCs) was investigated with a medium containing SB431542 as a small molecule and conjugated linolenic acid after 20 days. We used Immunocytochemistry and quantitative real-time polymerase chain reaction (RT-PCR) techniques to assess neural marker expression in differentiated cells. SEM imaging demonstrated that mESCs could strongly attach, stretch, and differentiate on PLA/CS/Wax scaffolds. MESCs that were cultured on PLA/CS/Wax scaffolds showed enhanced numbers of neural structures and neural markers including Nestin, NF-H, Tuj-1, and Map2 in neural induction medium compared to the control sample. These results revealed that electrospun PLA/CS/Wax scaffolds associated with the induction medium can assemble proper conditions for stem cell differentiation into NLCs. We hope that the development of new technologies in neural tissue engineering may pave a new avenue for neural tissue regeneration.

Small molecule of sphingosine as a rescue of dopaminergic cells: A cell therapy approach in neurodegenerative diseases therapeutics.

Multiple sclerosis (MS) patients should take medication such as fingolimod (FTY-720) for a long time, hence pharmaceutical effects on other neural cells such as dopaminergic cells are important. Dopaminergic cell line, BE(2)-M17, was treated by FTY-720 and then cell viability and genes involve in neurosurvival were investigated. It was disclosed that FTY-720 significantly stimulates Bcl2 overexpression. Whereas, it decreased intracellular reactive oxygen species production and cell membrane damage of dopaminergic cells. The increase in Bcl2/Bax ratio increased the cell metabolic activity and decreased propidium iodide-positive cells. Besides, FTY-720 induced the overexpression of CACNA1C, nNOS gene, and nitric oxide production. However, FTY-720 induced GABARA1 overexpression and eventually it could overcame to the cytotoxic effect of intracellular calcium. This cascade led to tyrosine hydroxylase and BDNF genes overexpression whereas FTY-720 did not change GDNF concentration in BE(2)-M17 cells. Concluding, it might be said that taking FTY-720 in MS patients did not induce adverse effect on dopaminergic cells.

PCL/gelatin nanofibrous scaffolds with human endometrial stem cells/Schwann cells facilitate axon regeneration in spinal cord injury.

The significant consequences of spinal cord injury (SCI) include sensory and motor disability resulting from the death of neuronal cells and axon degeneration. In this respect, overcoming the consequences of SCI including the recovery of sensory and motor functions is considered to be a difficult tasks that requires attention to multiple aspects of treatment. The breakthrough in tissue engineering through the integration of biomaterial scaffolds and stem cells has brought a new hope for the treatment of SCI. In the present study, human endometrial stem cells (hEnSCs) were cultured with human Schwann cells (hSC) in transwells, their differentiation into nerve-like cells was confirmed by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) and immunocytochemistry techniques. The differentiated cells (co-hEnSC) were then seeded on the poly ε-caprolactone (PCL)/gelatin scaffolds. The SEM images displayed the favorable seeding and survival of the cells on the scaffolds. The seeded scaffolds were then transplanted into hemisected SCI rats. The growth of neuronal cells was confirmed with immunohistochemical study using NF-H as a neuronal marker. Finally, the Basso, Beattie, and Bresnahan (BBB) test confirmed the recovery of sensory and motor functions. The results suggested that combination therapy using the differentiated hEnSC seeded on PCL/gelatin scaffolds has the potential to heal the injured spinal cord and to limit the secondary damage.

Human unrestricted somatic stem cells ameliorate sepsis-related acute lung injury in mice.

BACKGROUND AIMS: Sepsis and related disorders, especially acute lung injury (ALI), are the most challenging life-threatening diseases in the hospital intensive care unit. Complex pathophysiology, unbalanced immune condition, and high rate of mortality complicate the treatment of sepsis. Recently, cell therapy has been introduced as a promising option to recover the sepsis symptoms. The aim of this study was to investigate the therapeutic potential of human unrestricted somatic stem cells (USSCs) isolated from human umbilical cord blood in the mouse model of ALI. USSCs significantly enhanced the survival rate of mice suffering from ALI and suppressed concentrations of proinflammatory mediators TNF-α, and interleukin (IL)-6, and the level of anti-inflammatory cytokine IL-10. ALI mice injected by USSCs showed notable reduction in lung and liver injury, pulmonary edema, and hepatic enzymes, compared with the control group. These results determined the in vivo immunomodulatory effect of USSCs for recovery of immune balance and reduction of tissue injury in the mouse model of ALI. Therefore, USSCs can be a suitable therapeutic approach to manage sepsis disease through the anti-inflammatory potential.

Transplantation of miR-219 overexpressed human endometrial stem cells encapsulated in fibrin hydrogel in spinal cord injury.

Oligodendrocyte (OL) loss and demyelination occur after spinal cord injury (SCI). Stimulation of remyelination through transplantation of myelinating cells may be effective in improving function. For the repair strategy to be successful, the selection of a suitable cell and maintaining cell growth when cells are injected directly to the site of injury is important. In addition to selecting the type of cell, fibrin hydrogel was used as a suitable tissue engineering scaffold for this purpose. To test the relationship between myelination and functional improvement, the human endometrial stem cells (hEnSCs) were differentiated toward oligodendrocyte progenitor cells (OPCs) using overexpression of miR-219. Adult female Wistar rats were used to induce SCI by using a compression model and were randomly assigned to the following four experimental groups: SCI, Vehicle, hEnSC, and OPC. Ten days after injury, miR-219 overexpressed hEnSC-derived OPCs encapsulated in fibrin hydrogel, as an injectable scaffold, were injected to the injury site. In this study, with a focus on promoting functional recovery after SCI, the Basso-Beattie-Bresnahan test was performed to evaluate the recovery of motor function every week for 10 weeks and the histological assay was then performed. Results showed that the rate of motor function recovery was significantly higher in OPC group compared to SCI and vehicle groups but no marked differences were found between OPC and hEnSC groups, although, the rate of myelination in the OPC group was significantly higher than the other groups. These results demonstrated that remyelination was not the cause of recovery of motor function.

Combination therapy of mesenchymal stromal cells and sulfasalazine attenuates trinitrobenzene sulfonic acid induced colitis in the rat: The S1P pathway.

Adipose derived mesenchymal stem cells (ASCs) transplantation is a novel immunomodulatory therapeutic tool to ameliorate the symptom of inflammatory bowel disease (IBD). The objective of this study was to investigate the therapeutic effects of combined sufasalazine and ASCs therapy in a rat model of IBD. After induction of colitis in rats, ASCs were cultured and intraperitoneally injected (3 × 106 cells/kg) into the rats on Days 1 and 5 after inducing colitis, in conjunction with daily oral administration of low dose of sulfasalazine (30 mg/kg). The regenerative effects of combination of ASCs and sulfasalazine on ulcerative colitis were assessed by measuring body weight, colonic weight/length ratio, disease activity index, macroscopic scores, histopathological examinations, cytokine, and inflammation markers profiles. In addition, western blot analysis was used to assess the levels of nuclear factor-kappa B (NF-κB) and apoptosis related proteins in colitis tissues. Simultaneous treatment with ASCs and sulfasalazine was associated with significant amelioration of disease activity index, macroscopic and microscopic colitis scores, as well as inhibition of the proinflammatory cytokines in trinitrobenzene sulfonic acid (TNBS)-induced colitis. Moreover, combined ASCs and sulfasalazine therapy effectively inhibited the NF-κB signaling pathway, reduced the expression of Bax and prevented the loss of Bcl-2 proteins in colon tissue of the rats with TNBS-induced colitis. Furthermore, combined treatment with ASCs and sulfasalazine shifted inflammatory M1 to anti-inflammatory M2 macrophages by decreasing the levels of MCP1, CXCL9 and increasing IL-10, Arg-1 levels. In conclusion, combination of ASCs with conventional IBD therapy is potentially a much more powerful strategy to slow the progression of colitis via reducing inflammatory and apoptotic markers than either therapy alone.

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 extracellular vesicles-derived from mesenchymal stromal cells: A new therapeutic option in regenerative medicine.

Mesenchymal stem cells (MSCs) are adult multipotent cells that due to their ability to homing to damaged tissues and differentiate into specialized cells, are remarkable cells in the field of regenerative medicine. It's suggested that the predominant mechanism of MSCs in tissue repair might be related to their paracrine activity. The utilization of MSCs for tissue repair is initially based on the differentiation ability of these cells; however now it has been revealed that only a small fraction of the transplanted MSCs actually fuse and survive in host tissues. Indeed, MSCs supply the microenvironment with the secretion of soluble trophic factors, survival signals and the release of extracellular vesicles (EVs) such as exosome. Also, the paracrine activity of EVs could mediate the cellular communication to induce cell-differentiation/self-renewal. Recent findings suggest that EVs released by MSCs may also be critical in the physiological function of these cells. This review provides an overview of MSC-derived extracellular vesicles as a hopeful opportunity to advance novel cell-free therapy strategies that might prevail over the obstacles and risks associated with the use of native or engineered stem cells. EVs are very stable; they can pass the biological barriers without rejection and can shuttle bioactive molecules from one cell to another, causing the exchange of genetic information and reprogramming of the recipient cells. Moreover, extracellular vesicles may provide therapeutic cargo for a wide range of diseases and cancer therapy.

Polyurethane/Gelatin Nanofibrils Neural Guidance Conduit Containing Platelet-Rich Plasma and Melatonin for Transplantation of Schwann Cells.

The current study aimed to enhance the efficacy of peripheral nerve regeneration using a biodegradable porous neural guidance conduit as a carrier to transplant allogeneic Schwann cells (SCs). The conduit was prepared from polyurethane (PU) and gelatin nanofibrils (GNFs) using thermally induced phase separation technique and filled with melatonin (MLT) and platelet-rich plasma (PRP). The prepared conduit had the porosity of 87.17 ± 1.89%, the contact angle of 78.17 ± 5.30° and the ultimate tensile strength and Young's modulus of 5.40 ± 0.98 MPa and 3.13 ± 0.65 GPa, respectively. The conduit lost about 14% of its weight after 60 days in distilled water. The produced conduit enhanced the proliferation of SCs demonstrated by a tetrazolium salt-based assay. For functional analysis, the conduit was seeded with 1.50 × 104 SCs (PU/GNFs/PRP/MLT/SCs) and implanted into a 10-mm sciatic nerve defect of Wistar rat. Three control groups were used: (1) PU/GNFs/SCs, (2) PU/GNFs/PRP/SCs, and (3) Autograft. The results of sciatic functional index, hot plate latency, compound muscle action potential amplitude and latency, weight-loss percentage of wet gastrocnemius muscle and histopathological examination using hematoxylin-eosin and Luxol fast blue staining, demonstrated that using the PU/GNFs/PRP/MLT conduit to transplant SCs to the sciatic nerve defect resulted in a higher regenerative outcome than the PU/GNFs and PU/GNFs/PRP conduits.

Differential effect of Activin A and WNT3a on definitive endoderm differentiation on electrospun nanofibrous PCL scaffold.

The first step in the formation of hepatocytes and beta cells is the generation of definitive endoderm (DE) which involves a central issue in developmental biology. Human induced pluripotent stem cells (hiPSCs) have the pluripotency to differentiate into all three germ layers in vitro and have been considered potent candidates for regenerative medicine as an unlimited source of cells for therapeutic applications. In this study, we investigated the differentiating potential of hiPSCs on poly (ε-caprolactone) (PCL) nanofibrous scaffold into DE cells. Here, we demonstrate directed differentiation of hiPSCs by factors such as Activin A and Wnt3a. The differentiation was determined by immunofluoresence staining with Sox17, FoxA2 and Goosecoid (Gsc) and also by qRT-PCR analysis. The results of this study showed that hiPSCs, as a new cell source, have the ability to differentiate into DE cells with a high capacity and also demonstrate that three dimension (3D) culture provides a suitable nanoenviroment for growth, proliferation and differentiation of hiPSCs. PCL nanofibrous scaffold with essential supplements, stimulating factors and EB-derived cells is able to provide a novel method for enhancing functional differentiation of hiPSCs into DE cells.