Advances in Management of Spinal Cord Injury Using Stem Cell-derived Extracellular Vesicles: A Review Study.

Introduction: Spinal cord injury (SCI) is characterized by serious both motor and sensory disability of the limbs below the injured segment. It is the most traumatic disorder among central nervous system (CNS) conditions which not only leads to psychological and physical harm to patients but also results in a dramatic loss in the life quality. Many efforts have been developed to find a therapeutic approach for SCI; however, an effective treatment has not yet been found. The lack of effective treatment approach and rehabilitation of SCI underscores the need to identify novel approaches. Tissue engineering associated with stem cells has been recently introduced as an effective treatment approaches for traumatic SCI. Although, low survival rates, immune rejection, cell dedifferentiation, and tumorigenicity have been addressed for tissue engineering. Regenerative medicine is an interdisciplinary field developing and applying tissue engineering, stem cell (SC) therapy, and SC-derived extracellular vesicle therapy that aims to provide reliable and safe ways to replace injured tissues and organs. The application of mesenchymal stem cells-derived extracellular vesicles (MSC-EVs) has recently attracted attention to improve central nervous system dysfunction such as SCI, mainly by promoting neurogenesis and angiogenesis. Methods: In this review article the latest information of SCI improvement using stem cell-derived extracellular vesicles published data in the Web of Science, Scopus, Science Direct and Pub Med databases were collected. Results: The data collected show that MSC-EVs, including exosomes, alone or in combination with scaffolds can can regenerate the injured nerve in SCI. Conclusion: This study summarizes the efficacy of MSC-EVs, including exosomes, alone or in combination with scaffolds in the treatment of SCI and then discusses the therapeutic outcomes observed in SCI experimental models following treatment with MSC-EVs alone or loaded on scaffolds in particular collagen-based scaffolds. Highlights: The pathological process of SCI being very complex.A complete effective strategy has yet to be found for treatment of SCI in human.Exosomes derived-stem cells alone have great potential for the treatment of SCI.Various biocompatible scaffolds are good drug carriers for SCI treatment.Various biocompatible scaffolds are good carriers for exosomes. Plain Language Summary: Human with spinal cord injury (SCI) show serious motor and sensory disability of the limbs. Since there is no an effective treatment for SCI, researchers are trying to develop and find a new therapeutic approach for SCI. CNS tissue engineering with various stem cells sources as well as their derived extracellular vesicle has been extensively attracted for providing reliable and safe approach for SCI treatment. Extracellular vesicles are lipid bilayer membrane-enclosed organelles containing various biomolecules involved in a variety of complex intercellular communication systems. They are released from all cell types into their surrounding environment and are important vehicles for paracrine The application of stem cells-derived extracellular vesicles (MSC-EVs) has recently attracted attention to improve central nervous system dysfunction such as SCI, mainly by promoting neurogenesis and angiogenesis.

The Effect of Collagen and Fibrin Hydrogels Encapsulated with Adipose Tissue Mesenchymal Stem Cell-Derived Exosomes for Treatment of Spinal Cord Injury in a Rat Model.

Background: Mesenchymal stem cell (MSC) derived exosomes (MSC-DE) have been demonstrated to be potential candidates for the treatment of rat spinal cord injury (SCI). Objective: The effect of AD-MSC and AD-MSC-DE encapsulated into collagen and fibrin hydrogels on the treatment of SCI in a rat animal model was investigated for introducing a new effective SCI treatment method. Materials and Methods: The AD-MSC-DE was isolated using ultra-centrifugation at 100,000×g for 120 min and characterized by different methods. Fibrin and collagen hydrogels were synthesized and then mixed with AD-MSC-DE suspension. the characterized AD-MSC-DE were encapsulated into collagen and fibrin hydrogels. eighteen adult male Wister rats were randomly classified into 3 equal groups (n=6): the control group (SCI rat without treatment), SCI rat treated with either AD-MSC-DE encapsulated in collagen hydrogel or encapsulated in fibrin hydrogel groups. the treatment approaches were evaluated using clinical, histological, and molecular assays. Results: The AD-MSC-DE encapsulated into fibrin and collagen groups showed better clinical function than the control group. The AD-MSC-DE encapsulated into fibrin and collagen also improved SCI-induced polio and leuko-myelomalacia and leads to higher expression of NF protein than the control group. In the AD-MSC-DE encapsulated into collagen and fibrin leads to up-regulation the mean levels of NEFL (23.82 and 24.33, respectively), eNOS (24.31 and 24.53, respectively), and CK19 mRNAs (24.23 and 23.98, respectively) compared to the control group. Conclusion: The AD-MSC-DE encapsulated within ECM-based hydrogel scaffolds such as collagen and fibrin can regenerate the injured nerve in SCI rats and reduce spinal cord lesion-induced central neuropathic pain.

Effect of Photobiomodulation on Structure and Function of Extracellular Vesicle Secreted from Mesenchymal Stem Cells.

The current study intended to evaluate the effect of photobiomodulation on the morphology and function of EVs secreted from mesenchymal stem cells (MSCs) derived from periodontal ligament (PDL) and the adipose tissue (ADSCs) (from buccal fat pad) in vitro. These cells were irradiated at 660 nm or kept in dark as control. EVs were then isolated from each group using ultracentrifugation. EVs were defined by flow cytometry and Western blot. Electron microscopy (SEM) was used to study the morphology of EVs. Then, MTT and wound-healing scratch assays were applied to compare the cell survival and migration of human dermal fibroblast (HDF) cells treated with the EVs obtained from the four groups. According to SEM images, isolated EV were round and cup-shaped in all groups showing no destructive effects of laser irradiation on EV morphology. MTT test results revealed a statistically significant difference between the HDF cells treated with different EV groups from hPDLSCs-Dark in comparison with control (0 µg/mL) (P < 0.05) and treated with exosome from hPDLSCs-Irradiation cells compared with dark group (P < 0.05). However, scratch wound-healing assay did not show a significant difference between various groups (P ˃ 0.05). Further studies with different irradiation protocols are recommended to find an optimal strategy.

Amniotic membrane mesenchymal stem cells can differentiate into germ cells in vitro.

This is the first report on differentiation of mouse amniotic membrane mesenchymal stem cells (AM-MSCs) into male germ cells (GCs). AM-MSCs have the multipotent differentiation capacity and can be differentiated into various cell types. In the present study, AM-MSCs were induced for differentiation into GCs. AM-MSCs were isolated from mouse embryonic membrane by enzymatic digestion. AM-MSCs were characterized with osteogenic and adipogenic differentiation test and flow cytometric analysis of some CD-markers. AM-MSCs were induced to differentiate into GCs using a creative two-step method. Passage-3 AM-MSCs were firstly treated with 25 ng/ml bone morphogenetic protein 4 (BMP4) for 5 d and in continuing with 1 µM retinoic acid (RA) for 12 d (total treatment time was 17 d). At the end of the treatment period, real-time reverse transcription (RT)-PCR was performed to evaluate the expression of GC-specific markers-Itgb1, Dazl, Stra8, Piwil2, Mvh, Oct4, and c-Kit- in the cells. Moreover, flow cytometry and immunofluorescence staining were performed to evaluate the expression of Mvh and Dazl at protein level. Real-time RT-PCR showed that most of the tested markers were upregulated in the treated AM-MSCs. Furthermore, flow cytometric and immunofluorescence analyses both revealed that a considerable part of the treated cells expressed GC-specific markers. The percentage of positive cells for Mvh and Dazl was about 23 and 46%, respectively. Our results indicated that a number of AM-MSCs successfully differentiated into the GCs. Finally, it seems that AM-MSCs would be a potential source of adult pluripotent stem cells for in vitro generation of GCs and cell-based therapies for treatment of infertility.

Pd(II) and Pd(IV) complexes with 5-methyl-5-(4-pyridyl)hydantoin: synthesis, physicochemical, theoretical, and pharmacological investigation.

The reaction of K2[PdCl4] and PdCl2 with 5-methyl-5-(4-pyridyl)-2,4-imidazolidenedione (L) proceeded with the formation of two different Pd complexes, PdL2Cl2 (1) and PdL2Cl4 (2c), corresponded to a substitution reaction and a substitution reaction along with unanticipated oxidation, respectively. The nature of the oxidizing agent is unknown. These compounds have been studied by elemental analysis, IR, (1)H and (13)CNMR, molar conductivity, and cyclic voltammetry. In addition, structural optimization by DFT calculations and simulation of NMR spectra have been performed and compared with the experimental data. NBO analysis, HOMO and LUMO, have been used to elucidate the information regarding charge transfer within the molecules. Theoretical studies confirmed that in 1 and 2c the trans structures are about 41 and 33 kJ mol(-1) more stable than cis ones. Antibacterial activity and in vitro cytotoxicity of these compounds, as respectively assessed in six bacterial strains and two human tumor cell lines, have been investigated. Results showed the title complexes have the capacity of inhibiting the metabolic growth of bacteria and tumor cells to different extents.