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

Development and psychometric properties of appraisals of post traumatic spinal cord injury health scale in Iran

STUDY DESIGN

Development and psychometrics study OBJECTIVE: To evaluate the reliability and validity of a new version of Appraisals of Post-Traumatic Spinal Cord Injury Health Scale (APTSCIHS) in the Persian language for persons with spinal cord injury (SCI).

SETTING

The persons were selected from National Spinal Cord Injury Registry of Iran (NSCIR-IR) and Brain and Spinal Cord Injury Research center (BASIR).

METHOD

This was a mixed sequential exploratory study that performed in two phases. In the qualitative phase, a systematic scoping review and 12 interviews with the participants were done. Finally, items were generated. In the quantitative phase, face, content, construct and convergent validity were assessed to evaluate validity. To evaluate construct validity, a cross-sectional study was conducted on 305 persons with TSCI along with internal consistency and stability assessments. All quantitative data analyses were conducted using SPSS 22 software.

RESULTS

The content validity and reliability were indicated by Scale's Content Validity Ratio (S-CVR) = 0.73 and Scale's Content Validity Index (S-CVI) = 0.86, Cronbach's α = 0.9 and the Test re-test reliability using intra-class correlations were (ICC) = 0.97 to 0.98. Exploratory factor analysis determined eight factors which showed more than 52% of the variance. APTSCIHS had a significant and strong correlation with Appraisals of DisAbility Primary and Secondary Scale (ADAPSS) (r = 0.475, P < 0.001).

CONCLUSION

Results showed the 36 items APTSCIHS tool had an acceptable validity and reliability in Iran, and it can help health care providers or even administrators improve the quality of the rehabilitation services and quality of life.

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.

Endometrium Derived Stem Cells as Potential Candidates in Nervous System Repair

Limited cell division and lack of endogenous repair mechanisms in the central nervous system, hampers tissue repair following neurodegenerative diseases or tissue injuries. Unlike central nervous system; peripheral nervous system has some capacity to repair after injury, but in case of critical sized defects the use of supporting cells in the neural guidance channels seems inevitable to obtain a satisfactory functional recovery. Stem cell therapies have provided new frontiers in the repair of nervous system largely through paracrine secretion mechanisms. The therapeutic potential of stem cells differs according to their tissue of origin, mode of isolation, administration route, and passage number. During the past decades, studies have been focused on stem cells harvested from disposable tissues such as menstrual blood or biopsies from endometrium. These cells are characterized by their high differentiation and proliferation potential, ease of harvest, and lack of ethical concerns. In the current review, we will discuss the prospects and challenges of endometrial stem cells' application in nervous system repair.

Influence of reducing agents on in situ synthesis of gold nanoparticles and scaffold conductivity with emphasis on neural differentiation

BACKGROUND

Recorded advancements in nerve tissue regeneration have still not provided satisfactory results, and complete physiological recovery is not assured. The engineering of nanofibrous scaffolds provides a suitable platform for stem cell transplantation by controlling cell proliferation and differentiation to replace lost cells. In this study, a conductive scaffold was fabricated by in situ synthesis of gold nanoparticles (Au-NPs) on electrospun polycaprolactone/chitosan nanofibrous scaffolds and its effect on neural differentiation of mesenchymal stem cells was investigated.

METHOD

The conductive scaffold was prepared using polycaprolactone/chitosan solution containing soluble Au ions by electrospinning approach. In situ synthesis of Au-NPs was conducted using two reducing agents, Tetrakis(hydroxymethyl)phosphonium chloride (THPC) as an organophosphorus compound and formaldehyde, and also different reduction times. Morphology and distribution of the Au-NPs on the nanofibrous scaffolds were assessed using field emission scanning electron microscopy (FE-SEM) and energy dispersed X-ray spectroscopy (EDX). The hydrophilicity and biocompatibility of the scaffolds were determined by water contact angle and MTT assays respectively. The characterization of the scaffolds was proceeded by testing the porosity, tensile strength and electrical conductivity. Also, the scaffold's ability to support neural differentiation of mesenchymal stem cells was evaluated by immune-staining/blotting of Beta tubulin III.

RESULTS & CONCLUSION

FE-SEM and EDX results demonstrated the uniform distribution of Au-NPs on electrospun nanofibers made of a combination of polycaprolactone and chitosan (PCL/CS). We found that electrical conductivity of the scaffolds fabricated using THPC for 4 days and formaldehyde for 7 days was in the range of electrical conductivity of the scaffolds suitable for nerve regeneration. Contact angle measurements showed the effect of Au-NPs on the hydrophilic properties of the scaffolds, where the scaffold showed the porosity of 50% in the presence of Au-NPs. Au-NPs decoration on the scaffold decreased the mechanical properties with the ultimate strength of 14 (MPa). In vitro assessment demonstrated the potential of the fabricated conductive scaffold to enhance the attachment and proliferation of fibroblast cells, and differentiation potential of mesenchymal stem cells toward neuron-like cells. This designed scaffold holds promise as a future carrier and delivery platform in nerve tissue engineering.

Advanced approaches to regenerate spinal cord injury: The development of cell and tissue engineering therapy and combinational treatments

Spinal cord injury (SCI) is a central nervous system (CNS) devastate event that is commonly caused by traumatic or non-traumatic events. The reinnervation of spinal cord axons is hampered through a myriad of devices counting on the damaged myelin, inflammation, glial scar, and defective inhibitory molecules. Unfortunately, an effective treatment to completely repair SCI and improve functional recovery has not been found. In this regard, strategies such as using cells, biomaterials, biomolecules, and drugs have been reported to be effective for SCI recovery. Furthermore, recent advances in combinatorial treatments, which address various aspects of SCI pathophysiology, provide optimistic outcomes for spinal cord regeneration. According to the global importance of SCI, the goal of this article review is to provide an overview of the pathophysiology of SCI, with an emphasis on the latest modes of intervention and current advanced approaches for the treatment of SCI, in conjunction with an assessment of combinatorial approaches in preclinical and clinical trials. So, this article can give scientists and clinicians' clues to help them better understand how to construct preclinical and clinical studies that could lead to a breakthrough in spinal cord regeneration.

Improving motor neuron-like cell differentiation of hEnSCs by the combination of epothilone B loaded PCL microspheres in optimized 3D collagen hydrogel

Spinal cord regeneration is limited due to various obstacles and complex pathophysiological events after injury. Combination therapy is one approach that recently garnered attention for spinal cord injury (SCI) recovery. A composite of three-dimensional (3D) collagen hydrogel containing epothilone B (EpoB)-loaded polycaprolactone (PCL) microspheres (2.5 ng/mg, 10 ng/mg, and 40 ng/mg EpoB/PCL) were fabricated and optimized to improve motor neuron (MN) differentiation efficacy of human endometrial stem cells (hEnSCs). The microspheres were characterized using liquid chromatography-mass/mass spectrometry (LC-mas/mas) to assess the drug release and scanning electron microscope (SEM) for morphological assessment. hEnSCs were isolated, then characterized by flow cytometry, and seeded on the optimized 3D composite. Based on cell morphology and proliferation, cross-linked collagen hydrogels with and without 2.5 ng/mg EpoB loaded PCL microspheres were selected as the optimized formulations to compare the effect of EpoB release on MN differentiation. After differentiation, the expression of MN markers was estimated by real-time PCR and immunofluorescence (IF). The collagen hydrogel containing the EpoB group had the highest HB9 and ISL-1 expression and the longest neurite elongation. Providing a 3D permissive environment with EpoB, significantly improves MN-like cell differentiation and maturation of hEnSCs and is a promising approach to replace lost neurons after SCI.

Tissue-engineered nerve graft using silk-fibroin/polycaprolactone fibrous mats decorated with bioactive cerium oxide nanoparticles

The main aim of this study was to evaluate the efficacy of cerium oxide nanoparticles (CNPs) encapsulated in fabricated hybrid silk-fibroin (SF)/polycaprolactone (PCL) nanofibers as an artificial neural guidance conduit (NGC) applicable for peripheral nerve regeneration. The NGC was prepared by PCL and SF filled with CNPs. The mechanical properties, contact angle, and cell biocompatibility experiments showed that the optimized concentration of CNPs inside SF and SF/PCL wall of conduits was 1% (wt/wt). The SEM image analysis showed the nanoscale texture of the scaffold in different topologies depend on composition with fiber diameters at about 351 ± 54 nm and 420 ± 73 nm respectively for CNPs + SF and CNPs + SF/PCL fibrous mats. Furthermore, contact angle measurement confirmed the hydrophilic behavior of the membranes, ascribable to the SF content and surface modification through modified methanol treatment. The balance of morphological and biochemical properties of hybrid CNPs 1% (wt/wt) + SF/PCL construct improves cell adhesion and proliferation in comparison with lower concentrations of CNPs in nanofibrous scaffolds. The release of CNPs 1% (wt/wt) from both CNPs + SF and CNPs+ SF/PCL fibrous mats was highly controlled and very slow during the extended time of incubation until 60 days. Fabricated double-layered NGC using CNPs + SF and CNPs + SF/PCL fibers was consistent for application in nervous tissue engineering and regenerative medicine from a structural and biocompatible perspective.

Defining the role of 17β-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 17β-estradiol plays important roles in the processes of development, maturation, and function of nervous system. In the present research, the impact of 17β-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 17β-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 17β-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.

Proanthocyanidin as a crosslinking agent for fibrin, collagen hydrogels and their composites with decellularized Wharton’s-jelly-extract for tissue engineering applications

In tissue engineering, natural hydrogel scaffolds gained considerable attention due to their biocompatibility and similarity to macromolecular-based components in the body. However, their low mechanical strength and high degradation degree limit their biomedical application. By varying the composition of hydrogels, their biochemical and mechanical properties can be improved. In this study, the stability of fibrin and collagen hydrogels and their composites with decellularized Wharton’s jelly extract (DEWJ) was improved using proanthocyanidin (PA) as a cross-linker, extracted from grape seeds. The cytocompatibility, physicochemical and mechanical properties of the hydrogels were evaluated. Human endometrial stem cells (hEnSCs) were seeded on the hydrogels and their attachment, morphology, and proliferation were investigated using a scanning electron and optical microscopy. Our results showed that hydrogels containing DEWJ along with PA enhance cell proliferation and showed higher mechanical properties compared with the fibrin and collagen hydrogel. The results present the potential utility of these hydrogels in tissue engineering and for application in three-dimensional culture.