Mesenchymal stem cells in the treatment of spinal cord injuries: A review

Biomaterials reinforced MSCs transplantation for spinal cord injury repair

Due to the complex pathophysiological mechanism, spinal cord injury (SCI) has become one of the most intractable central nervous system (CNS) diseases to therapy. Stem cell transplantation, mesenchymal stem cells (MSCs) particularly, appeals to more and more attention along with the encouraging therapeutic results for the functional regeneration of SCI. However, traditional cell transplantation strategies have some limitations, including the unsatisfying survival rate of MSCs and their random diffusion from the injection site to ambient tissues. The application of biomaterials in tissue engineering provides a new horizon. Biomaterials can not only confine MSCs in the injured lesions with higher cell viability, but also promote their therapeutic efficacy. This review summarizes the strategies and advantages of biomaterials reinforced MSCs transplantation to treat SCI in recent years, which are clarified in the light of various therapeutic effects in pathophysiological aspects of SCI.

Berberine loaded chitosan nanoparticles encapsulated in polysaccharide-based hydrogel for the repair of spinal cord

The potential of berberine loaded in chitosan nanoparticles (BerNChs) within a hybrid of alginate (Alg) and chitosan (Ch) hydrogel was investigated for the substrate which is known as an inhibit activator proteins. The physicochemical properties of the developed Alg-Ch hydrogel were investigated by fourier-transform infrared spectroscopy. The swelling ability and degradation rate of hydrogels were also analyzed in a phosphate-buffered saline solution at physiological pH. The seeded scaffolds with endometrial stem cells as well as scaffolds alone were then transplanted into hemisected SCI rats. The SEM images displayed the favorable seeding and survival of the cells on the Alg-Ch/BerNChs hydrogel scaffold. The obtained data from immunostining of neuroflilament (NF), as a neuronal growth marker, in the various groups showed that the lowest and highest immunoractivity was belonged to the control and Alg-Ch/BerNCh seeded with ESCs groups, respectively. Finally, the Basso, Beattie, and Bresnahan (BBB) test confirmed the recovery of sensory and motor functions, clinically. The results suggested that combination therapy using the endometrial stem cells seeded on Alg-Ch/BerNChs hydrogel scaffold has the potential to regenerate the injured spinal cord and to limit the secondary damage.

Human Mesenchymal Stem Cells for Spinal Cord Injury

Spinal Cord Injury (SCI), as a devastating and life-altering neurological disorder, is one of the most serious health issues. Currently, the management of acute SCI includes pharmacotherapy and surgical decompression. Both the approaches have been observed to have adverse physiological effects on SCI patients. Therefore, novel therapeutic targets for the management of SCI are urgently required for developing cell-based therapies. Multipotent stem cells, as a novel strategy for the treatment of tissue injury, may provide an effective therapeutic option against many neurological disorders. Mesenchymal stem cells (MSCs) or multipotent stromal cells can typically self-renew and generate various cell types. These cells are often isolated from bone marrow (BM-MSCs), adipose tissues (AD-MSCs), umbilical cord blood (UCB-MSCs), and placenta (PMSCs). MSCs have remarkable potential for the development of regenerative therapies in animal models and humans with SCI. Herein, we summarize the therapeutic potential of human MSCs in the treatment of SCI.

Improving Culture Conditions, Proliferation, and Migration of Porcine Mesenchymal Stem Cells on Spinal Cord Contusion Injury Model in vitro

Adipose tissue-derived mesenchymal stem cells (AD-MSCs) are promising for cell therapy in spinal cord injury (SCI). The pig is one of the most approximate models of many human diseases, including SCI. In our study, we selected the optimal conditions for the culture of porcine AD-MSCs and developed an in vitro SCI model based on the culture of cells in injured spinal cord extracts (SCE) 3 days and 6 weeks after SCI. We show that Dulbecco's Modified Eagle Medium (DMEM) with 20% serum content, supplemented with a combination of 5 mM L-ascorbate-2-phosphate and nonessential amino acids, stimulated a typical fibroblast-like morphology and high proliferation of porcine AD-MSCs. SCE caused a higher proliferation of porcine AD-MSCs compared with extracts from an intact spinal cord. The optimal proliferating effect was achieved using rostral 3 days SCE, and proliferation was lower in caudal and central SCE. Porcine AD-MSCs migration to the 3 days and 6 weeks SCE was higher than to an intact one and preferred the rostral SCE, avoiding central and caudal SCE. We also studied 13 cytokines contained in SCE but did not observe any definite relationship between some analyte concentrations and a change in the behavior of AD-MSCs.

Combined treatment with enteric neural stem cells and chondroitinase ABC reduces spinal cord lesion pathology

BACKGROUND

Spinal cord injury (SCI) presents a significant challenge for the field of neurotherapeutics. Stem cells have shown promise in replenishing the cells lost to the injury process, but the release of axon growth-inhibitory molecules such as chondroitin sulfate proteoglycans (CSPGs) by activated cells within the injury site hinders the integration of transplanted cells. We hypothesised that simultaneous application of enteric neural stem cells (ENSCs) isolated from the gastrointestinal tract, with a lentivirus (LV) containing the enzyme chondroitinase ABC (ChABC), would enhance the regenerative potential of ENSCs after transplantation into the injured spinal cord.

METHODS

ENSCs were harvested from the GI tract of p7 rats, expanded in vitro and characterised. Adult rats bearing a contusion injury were randomly assigned to one of four groups: no treatment, LV-ChABC injection only, ENSC transplantation only or ENSC transplantation+LV-ChABC injection. After 16 weeks, rats were sacrificed and the harvested spinal cords examined for evidence of repair.

RESULTS

ENSC cultures contained a variety of neuronal subtypes suitable for replenishing cells lost through SCI. Following injury, transplanted ENSC-derived cells survived and ChABC successfully degraded CSPGs. We observed significant reductions in the injured tissue and cavity area, with the greatest improvements seen in the combined treatment group. ENSC-derived cells extended projections across the injury site into both the rostral and caudal host spinal cord, and ENSC transplantation significantly increased the number of cells extending axons across the injury site. Furthermore, the combined treatment resulted in a modest, but significant functional improvement by week 16, and we found no evidence of the spread of transplanted cells to ectopic locations or formation of tumours.

CONCLUSIONS

Regenerative effects of a combined treatment with ENSCs and ChABC surpassed either treatment alone, highlighting the importance of further research into combinatorial therapies for SCI. Our work provides evidence that stem cells taken from the adult gastrointestinal tract, an easily accessible source for autologous transplantation, could be strongly considered for the repair of central nervous system disorders.

Combined administration of platelet rich plasma and autologous bone marrow aspirate concentrate for spinal cord injury: a descriptive case series

Administration of platelet rich plasma (PRP) and bone marrow aspirate concentrate (BMAC) has shown some promise in the treatment of neurological conditions; however, there is limited information on combined administration. As such, the purpose of this study was to assess safety and functional outcomes for patients administered combined autologous PRP and BMAC for spinal cord injury (SCI). This retrospective case series included seven patients who received combined treatment of autologous PRP and BMAC via intravenous and intrathecal administration as salvage therapy for SCI. Patients were reviewed for adverse reactions and clinical outcomes using the Oswestry Disability Index (ODI) for up to 1 year, as permitted by availability of follow-up data. Injury levels ranged from C3 through T11, and elapsed time between injury and salvage therapy ranged from 2.4 months to 6.2 years. Post-procedure complications were mild and rare, consisting only of self-limited headache and subjective memory impairment in one patient. Four patients experienced severe disability prior to PRP combined with BMAC injection, as evidenced by high (> 48/100) Oswestry Disability Index scores. Longitudinal Oswestry Disability Index scores for two patients with incomplete SCI at C6 and C7, both of whom had cervical spine injuries, demonstrated a decrease of 28–40% following salvage therapy, representing an improvement from severe to minimal disability. In conclusion, intrathecal/intravenous co-administration of PRP and BMAC resulted in no significant complications and may have had some clinical benefits. Larger clinical studies are needed to further test this method of treatment for patients with SCI who otherwise have limited meaningful treatment options. This study was reviewed and approved by the OhioHealth Institutional Review Board (IRB No. 1204946) on May 16, 2018.

Recent advances in mesenchymal stem cell membrane-coated nanoparticles for enhanced drug delivery

Studies of nanomedicine have achieved dramatic progress in recent decades. However, the main challenges that traditional nanomedicine has to overcome include low accumulation at target sites and rapid clearance from the blood circulation. An interesting approach using cell membrane coating technology has emerged as a possible way to overcome these limitations, owing to the enhanced targeted delivery and reduced immunogenicity of cell membrane moieties. Mesenchymal stem cell (MSC) therapy has been investigated for treating various diseases, ranging from inflammatory diseases to tissue damage. Recent studies with engineered modified MSCs or MSC membranes have focused on enhancing cell therapeutic efficacy. Therefore, bioengineering strategies that couple synthetic nanoparticles with MSC membranes have recently received much attention due to their homing ability and tumor tropism. Given the various membrane receptors on their surfaces, MSC membrane-coated nanoparticles are an effective method with selective targeting properties, allowing entry into specific cells. Here, we review recent progress on the use of MSC membrane-coated nanoparticles for biomedical applications, particularly in the two main antitumor and anti-inflammatory fields. The combination of a bioengineered cell membrane and synthesized nanoparticles presents a wide range of possibilities for the further development of targeted drug delivery, showing the potential to enhance the therapeutic efficacy for treating various diseases.

Combined Cell Therapy in the Treatment of Neurological Disorders

Cell therapy of neurological diseases is gaining momentum. Various types of stem/progenitor cells and their derivatives have shown positive therapeutic results in animal models of neurological disorders and in clinical trials. Each tested cell type proved to have its advantages and flaws and unique cellular and molecular mechanism of action, prompting the idea to test combined transplantation of two or more types of cells (combined cell therapy). This review summarizes the results of combined cell therapy of neurological pathologies reported up to this point. The number of papers describing experimental studies or clinical trials addressing this subject is still limited. However, its successful application to the treatment of neurological pathologies including stroke, spinal cord injury, neurodegenerative diseases, Duchenne muscular dystrophy, and retinal degeneration has been reported in both experimental and clinical studies. The advantages of combined cell therapy can be realized by simple summation of beneficial effects of different cells. Alternatively, one kind of cells can support the survival and functioning of the other by enhancing the formation of optimum environment or immunomodulation. No significant adverse events were reported. Combined cell therapy is a promising approach for the treatment of neurological disorders, but further research needs to be conducted.

The leading edge: Emerging neuroprotective and neuroregenerative cell-based therapies for spinal cord injury

Spinal cord injuries (SCIs) are associated with tremendous physical, social, and financial costs for millions of individuals and families worldwide. Rapid delivery of specialized medical and surgical care has reduced mortality; however, long-term functional recovery remains limited. Cell-based therapies represent an exciting neuroprotective and neuroregenerative strategy for SCI. This article summarizes the most promising preclinical and clinical cell approaches to date including transplantation of mesenchymal stem cells, neural stem cells, oligodendrocyte progenitor cells, Schwann cells, and olfactory ensheathing cells, as well as strategies to activate endogenous multipotent cell pools. Throughout, we emphasize the fundamental biology of cell-based therapies, critical features in the pathophysiology of spinal cord injury, and the strengths and limitations of each approach. We also highlight salient completed and ongoing clinical trials worldwide and the bidirectional translation of their findings. We then provide an overview of key adjunct strategies such as trophic factor support to optimize graft survival and differentiation, engineered biomaterials to provide a support scaffold, electrical fields to stimulate migration, and novel approaches to degrade the glial scar. We also discuss important considerations when initiating a clinical trial for a cell therapy such as the logistics of clinical-grade cell line scale-up, cell storage and transportation, and the delivery of cells into humans. We conclude with an outlook on the future of cell-based treatments for SCI and opportunities for interdisciplinary collaboration in the field.

Advances in immunotherapy for the treatment of spinal cord injury

Spinal cord injury (SCI) is a leading cause of morbidity and disability in the world. Over the past few decades, the exact molecular mechanisms describing secondary, persistent injuries, as well as primary and transient injuries, have attracted massive attention to the clinicians and researchers. Recent investigations have distinctly shown the critical roles of innate and adaptive immune responses in regulating sterile neuroinflammation and functional outcomes after SCI. In past years, some promising advances in immunotherapeutic options have efficaciously been identified for the treatment of SCI. In our narrative review, we have mainly focused on the new therapeutic strategies such as the maturation and apoptosis of immune cells by several agents, mesenchymal stem cells (MSCs) as well as multi-factor combination therapy, which have recently provided novel ideas and prospects for the future treatment of SCI. This article also illustrates the latest progress in clarifying the potential roles of innate and adaptive immune responses in SCI, the progression and specification of prospective immunotherapy and outstanding issues in the area.

Intravenous Administration of Heat Shock-Treated MSCs Can Improve Neuroprotection and Neuroregeneration in Canine Spinal Cord Injury Model

Simple Summary

Mesenchymal stem cells (MSCs), which are found in connective tissues, can be used to treat spinal cord injury (SCI) in dogs. These stem cells have the ability to repair damaged tissues and can be transplanted into the injured area. While this is considered a promising treatment, the transplanted cells often do not survive in the injured spinal cord. In this study, we found that heat shock treatment, i.e., exposure to high temperatures, increased the efficacy of MSC treatment for SCI.

Abstract

Transplantation of mesenchymal stem cells (MSCs) is a promising treatment for spinal cord injury (SCI). However, many transplanted cells die within a few days, eventually limiting the efficacy of cellular therapy. To overcome this problem, we focused on the potential of heat shock (HS) proteins in facilitating recovery from cell damage and protecting against cytotoxicity. PCR results showed that the expression of neurotrophic factor, anti-inflammatory, stemness, and homing genes increased in HS-treated MSCs. We investigated whether HS-treated MSCs could promote recovery of hindlimb function in an acute canine SCI model. We compared the effects of intravenous transplantation with (i) lactated Ringer’s solution as a control, (ii) green fluorescent protein-expressing MSCs (MSCs-GFP), and (iii) GFP-expressing and HS-treated MSCs (MSCs-GFP-HS). Spinal cords were harvested at four weeks and used for Western blot and histopathological analyses. The MSCs-GFP-HS group showed significant improvements in hindlimb function from weeks 3 and 4 compared with the other groups. This group also showed higher expression of neural markers, fewer intervening fibrotic changes, and pronounced myelination. These results suggest that induction of an HS response in MSCs could promote neural sparing. In conclusion, transplantation of HS-treated MSCs could improve neuroprotection and neuroregeneration in acute SCI.

A Review of Low-Level Laser Therapy for Spinal Cord Injury: Challenges And Safety

Introduction: Damage to the spinal cord is a central nervous system disorder that results in direct damage to neural cells (axons, cell bodies) and glia, followed by autonomic, motor and sensory impairments. Inflammatory response after this injury can contribute to secondary tissue damage that leads to further behavioral and functional disorders. Inflammation is a complex process, which occurs after an injury. If this progressive process is not well controlled can lead to additional damage to the spinal cord which is preventing neural improvement and regeneration and, which ultimately will not provide good clinical consequences. Inflammation in the injured spinal cord is a physiological response that causes the death of glial and neuronal cells. The reduction of the initial inflammatory process after damage to the spinal cord is one of the important therapeutic strategies. It has been proposed that low-level laser (LLL) therapy, as a noninvasive manner, can modulate inflammatory processes, which leads to a significant improvement in neurological symptoms after spinal cord injury (SCI). Methods: A comprehensive review was performed on SCI, the etiologies, and treatment methods using the keywords spinal cord injury, low-level laser, and inflammation in valid medical databases such as Google Scholar, PubMed, and Elsevier (76 articles). Among the collected papers, articles that were most relevant to the purposes of the study were selected and studied. Results: LLL therapy was able to reduce inflammation and also attenuate neuronal damage after spinal cord damage. Conclusion: The present study illustrates that LLL therapy has positive effects on improving functional recovery and regulating the inflammatory function in the SCI.

Intracerebroventricular Delivery of Human Umbilical Cord Mesenchymal Stem Cells as a Promising Therapy for Repairing the Spinal Cord Injury Induced by Kainic Acid

Spinal cord injury (SCI) is a common pathological condition that leads to permanent or temporal loss of motor and autonomic functions. Kainic acid (KA), an agonist of kainate receptors, a type of ionotropic glutamate receptor, is widely used to induce experimental neurodegeneration models of CNS. Mesenchymal Stem Cells (MSC) therapy applied at the injured nervous tissue have emerged as a promising therapeutic treatment. Here we used a validated SCI experimental model in which an intraparenchymal injection of KA into the C5 segment of rat spinal cord induced an excitotoxic lesion. Three days later, experimental animals were treated with an intracerebroventricular injection of human umbilical cord (hUC) MSC whereas control group only received saline solution. Sensory and motor skills as well as neuronal and glial reaction of both groups were recorded. Differences in motor behavior, neuronal counting and glial responses were observed between hUC-MSC-treated and untreated rats. According to the obtained results, we suggest that hUC-MSC therapy delivered into the fourth ventricle using the intracerebroventricular via can exert a neuroprotective or neurorestorative effect on KA-injected animals.

Human dental stem cells of the apical papilla associated to BDNF-loaded pharmacologically active microcarriers (PAMs) enhance locomotor function after spinal cord injury

There is no treatment for spinal cord injury (SCI) that fully repairs the damages. One strategy is to inject mesenchymal stem cells around the lesion to benefit from their immunomodulatory properties and neuroprotective effect. Our hypothesis was that the combination of dental stem cells from the apical papilla (SCAP) with pharmacologically active microcarriers (PAMs) releasing brain-derived neurotrophic factor (BDNF) would improve rat locomotor function by immunomodulation and neuroprotection. BDNF-PAMs were prepared by solid/oil/water emulsion of poly(L-lactide-co-glycolide) and nanoprecipitated BDNF and subsequent coating with fibronectin. SCAP were then seeded on BDNF-PAMs. SCAP expression of neuronal and immunomodulatory factors was evaluated in vitro. SCAP BDNF-PAMs were injected in a rat spinal cord contusion model and their locomotor function was evaluated by Basso, Beattie, and Bresnahan (BBB) scoring. Impact on inflammation and neuroprotection/axonal growth was evaluated by immunofluorescence. Culture on PAMs induced the overexpression of immunomodulatory molecules and neural/neuronal markers. Injection of SCAP BDNF-PAMs at the lesion site improved rat BBB scoring, reduced the expression of inducible nitric oxide synthase and increased the expression of βIII tubulin, GAP43, and 5-HT. These results confirm the suitability and versatility of PAMs as combined drug and cell delivery system for regenerative medicine applications but also that BDNF-PAMs potentialize the very promising therapeutic potential of SCAP in the scope of SCI.

Mechanisms underlying the protective effects of mesenchymal stem cell-based therapy

Mesenchymal stem cells (MSCs) have been extensively investigated for the treatment of various diseases. The therapeutic potential of MSCs is attributed to complex cellular and molecular mechanisms of action including differentiation into multiple cell lineages and regulation of immune responses via immunomodulation. The plasticity of MSCs in immunomodulation allow these cells to exert different immune effects depending on different diseases. Understanding the biology of MSCs and their role in treatment is critical to determine their potential for various therapeutic applications and for the development of MSC-based regenerative medicine. This review summarizes the recent progress of particular mechanisms underlying the tissue regenerative properties and immunomodulatory effects of MSCs. We focused on discussing the functional roles of paracrine activities, direct cell-cell contact, mitochondrial transfer, and extracellular vesicles related to MSC-mediated effects on immune cell responses, cell survival, and regeneration. This will provide an overview of the current research on the rapid development of MSC-based therapies.

Alleviation of medial meniscal transection-induced osteoarthritis pain in rats by human adipose derived mesenchymal stem cells

Knee osteoarthritis (KOA) is a degenerative joint disorder manifested with deformity, pain, and functional disability due to damage of the articular cartilage. Cell therapy with mesenchymal stem cells (MSCs) holds great promise to alleviate or even cure the degenerative diseases including KOA. However, the evidence of efficacy of human adipose tissue-derived MSCs (hAdMSCs) on KOA therapy remains limited. Here, we evaluate the therapeutic efficacy of hAdMSCs for KOA, using a medial meniscal transection (MMT) rat model. Our study demonstrated that intra-articular injection of 1.25×10⁶ hAdMSCs significantly attenuated MMT-induced joint pain in a KOA rats model. The results of this study provide strong evidence that hAdMSCs-based therapy can be regarded as a prominent treatment option for patients with KOA.

Cell Therapies for Spinal Cord Injury: Trends and Challenges of Current Clinical Trials

Cell therapies have the potential to revolutionize the treatment of spinal cord injury. Basic research has progressed significantly in recent years, with a plethora of cell types now reaching early-phase human clinical trials, offering new strategies to repair the spinal cord. However, despite initial enthusiasm for preclinical and early-phase clinical trials, there has been a notable hiatus in the translation of cell therapies to routine clinical practice. Here, we review cell therapies that have reached clinical trials for spinal cord injury, providing a snapshot of all registered human trials and a summary of all published studies. Of registered trials, the majority have used autologous cells and approximately a third have been government funded, a third industry sponsored, and a third funded by university or healthcare systems. A total of 37 cell therapy trials have been published, primarily using stem cells, although a smaller number have used Schwann cells or olfactory ensheathing cells. Significant challenges remain for cell therapy trials in this area, including achieving stringent regulatory standards, ensuring appropriately powered efficacy trials, and establishing sustainable long-term funding. However, cell therapies hold great promise for human spinal cord repair and future trials must continue to capitalize on the exciting developments emerging from preclinical studies.

Regenerative medicine for spinal cord injury: focus on stem cells and biomaterials

INTRODUCTION

Spinal cord injury (SCI) is a dramatic medical pathology consequence of a trauma (primary injury). However, most of the post-traumatic degeneration of the tissue is caused by the so-called secondary injury, which is known to be a multifactorial process. This, indeed, includes a wide spectrum of events: blood-brain barrier dysfunction, local inflammation, neuronal death, demyelination and disconnection of nerve pathways.

AREAS COVERED

Cell therapy represents a promising cure to target diseases and disorders at the cellular level, by restoring cell population or using cells as carriers of therapeutic cargo. In particular, regenerative medicine with stem cells represents the most appealing category to be used, thanks to their peculiar features.

EXPERT OPINION

Many preclinical research studies demonstrated that cell treatment can improve animal sensory/motor functions and so demonstrated to be very promising for clinical trials. In particular, recent advances have led to the development of biomaterials aiming to promote in situ cell delivery. This review digs into this topic discussing the possibility of cell treatment to improve medical chances in SCI repair.

Stem Cell Clinical Trials in Spinal Cord Injury: A Brief Review of Studies in the United States

Background: Although many therapeutic approaches have been attempted to treat spinal cord injury, cellular transplantation offers the greatest promise in reconstituting the architecture of the damaged cord. Methods: A literature review was conducted to search for clinical trials investigating stem cells as treatment for spinal cord injury in the United States. Results: Overall, eight studies met inclusion criteria. Of the included studies, four were identified as being terminated, suspended, or not yet recruiting. Two studies were identified as currently recruiting, including one phase one trial evaluating stereotactic injections of human spinal cord-derived neural stem cells in patients with chronic spinal cord injuries, and one trial of transplantation of autologous bone marrow derived stem cells via paraspinal injections, intravenous injections, and intranasal placement. One study was identified as an active study, a phase one trial of intrathecal injection of 100 million autologous, ex-vivo expanded, adipose-derived mesenchymal stem cells. One trial that was listed as completed is a phase 1/2a, dose escalation study, investigating stereotactic injection of human embryonic stem cell derived oligodendrocyte progenitor cells. Conclusions: Although few significant publications have emerged to this point, current trial results are promising.

Vascular Endothelial Growth Factor-Transfected Bone Marrow Mesenchymal Stem Cells Improve the Recovery of Motor and Sensory Functions of Rats With Spinal Cord Injury

STUDY DESIGN

Basic science.

OBJECTIVE

The aim of this study was to examine the effect of vascular endothelial growth factor (VEGF)-transfected bone marrow mesenchymal stem cells (BMSCs) on the recovery of motor and sensory functions of rats with spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

There is no effective treatment to protect against SCI. BMSCs have been widely applied to the treatment of nervous system damage due to the function of prompt neurite growth and inhibition of demyelination following injury.

METHODS

VEGF-transfected BMSCs were injected to rats with SCI and the recovery of motor and sensory functions was observed. The Basso, Beattie, and Bresnahan, mechanical withdrawal threshold and thermal withdraw latency grading was conducted to assess the recovery status of motor and sensory functions of the SCI rats. The expression of VEGF, CD31, and NF200 was detected by immunofluorescence.

RESULTS

The recovery of the rat motor and sensory functions in the VEGF-transfected BMSC (BMSC-VEGF) group was higher than those of the other groups with the exception of the Sham group (P < 0.05). The expression of the CD31 and NF200 proteins in the rat SCI regions was the highest in the BMSC-VEGF group, whereas the survival of BMSC in the BMSC-VEGF group was increased compared with that in the BMSC-Ad group. In addition, the injection of VEGF-transfected BMSCs can improve the angiogenesis of the injured area and retain the survival of injected cells and neurons.

CONCLUSION

The injection of BMSC-VEGF improved the recovery of motor function in SCI rats.

LEVEL OF EVIDENCE

N/A.

CELLTOP Clinical Trial: First Report From a Phase 1 Trial of Autologous Adipose Tissue-Derived Mesenchymal Stem Cells in the Treatment of Paralysis Due to Traumatic Spinal Cord Injury

Spinal cord injury (SCI) is a devastating condition with limited pharmacological treatment options to restore function. Regenerative approaches have recently attracted interest as an adjuvant to current standard of care. Adipose tissue-derived (AD) mesenchymal stem cells (MSCs) represent a readily accessible cell source with high proliferative capacity. The CELLTOP study, an ongoing multidisciplinary phase 1 clinical trial conducted at Mayo Clinic (ClinicalTrials.gov Identifier: NCT03308565), is investigating the safety and efficacy of intrathecal autologous AD-MSCs in patients with blunt, traumatic SCI. In this initial report, we describe the outcome of the first treated patient, a 53-year-old survivor of a surfing accident who sustained a high cervical American Spinal Injury Association Impairment Scale grade A SCI with subsequent neurologic improvement that plateaued within 6 months following injury. Although he improved to an American Spinal Injury Association grade C impairement classification, the individual continued to be wheelchair bound and severely debilitated. After study enrollment, an adipose tissue biopsy was performed and MSCs were isolated, expanded, and cryopreserved. Per protocol, the patient received an intrathecal injection of 100 million autologous AD-MSCs infused after a standard lumbar puncture at the L3-4 level 11 months after the injury. The patient tolerated the procedure well and did not experience any severe adverse events. Clinical signs of efficacy were observed at 3, 6, 12, and 18 months following the injection in both motor and sensory scores based on International Standards for Neurological Classification of Spinal Cord Injury. Thus, in this treated individual with SCI, intrathecal administration of AD-MSCs was feasible and safe and suggested meaningful signs of improved, rather than stabilized, neurologic status warranting further clinical evaluation.

Mesenchymal Stem Cell-Laden Hydrogel Microfibers for Promoting Nerve Fiber Regeneration in Long-Distance Spinal Cord Transection Injury

Mesenchymal stem cell (MSC)-based regenerative medicine is widely considered as a promising approach for repairing tissue and re-establishing function in spinal cord injury (SCI). However, low survival rate, uncontrollable migration, and differentiation of stem cells after implantation represent major challenges toward the clinical deployment of this approach. In this study, we fabricated three-dimensional MSC-laden microfibers via electrospinning in a rotating cell culture to mimic nerve tissue, control stem cell behavior, and promote integration with the host tissue. The hierarchically aligned fibrin hydrogel was used as the MSC carrier though a rotating method and the aligned fiber structure induced the MSC-aligned adhesion on the surface of the hydrogel to form microscale cell fibers. The MSC-laden microfiber implantation enhanced the donor MSC neural differentiation, encouraged the migration of host neurons into the injury gap and significantly promoted nerve fiber regeneration across the injury site. Abundant GAP-43- and NF-positive nerve fibers were observed to regenerate in the caudal, rostral, and middle sites of the injury position 8 weeks after the surgery. The NF fiber density reached to 29 ± 6 per 0.25 mm² at the middle site, 82 ± 13 per 0.25 mm² at the adjacent caudal site, and 70 ± 23 at the adjacent rostral site. Similarly, motor axons labeled with 5-hydroxytryptamine were significantly regenerated in the injury gap, which was 122 ± 22 at the middle injury site that was beneficial for motor function recovery. Most remarkably, the transplantation of MSC-laden microfibers significantly improved electrophysiological expression and re-established limb motor function. These findings highlight the combination of MSCs with microhydrogel fibers, the use of which may become a promising method for MSC implantation and SCI repair.

Stem Cells Therapy for Spinal Cord Injury: An Overview of Clinical Trials

Spinal cord injury (SCI) is a traumatic lesion that causes disability with temporary or permanent sensory and/or motor deficits. The pharmacological approach still in use for the treatment of SCI involves the employment of corticosteroid drugs. However, SCI remains a very complex disorder that needs future studies to find effective pharmacological treatments. SCI actives a strong inflammatory response that induces a loss of neurons followed by a cascade of events that lead to further spinal cord damage. Many experimental studies demonstrate the therapeutic effect of stem cells in SCI due to their capacity to differentiate into neuronal cells and by releasing neurotrophic factors. Therefore, they appear to be a valid strategy to use in the field of regenerative medicine. The purpose of this paper is to provide an overview of clinical trials, recorded in clinical trial.gov during 2005-2019, aimed to evaluate the use of stem cell-based therapy in SCI. The results available thus far show the safety and efficacy of stem cell therapy in patients with SCI. However, future trials are needed to investigate the safety and efficacy of stem cell transplantation.

Autologous Transplantation of Adipose-Derived Stem Cells to Treat Acute Spinal Cord Injury: Evaluation of Clinical Signs, Mental Signs, and Quality of Life

BACKGROUD

Spinal cord injury (SCI) is damage that can cause a temporary or permanent change in spinal cord functions.

AIM:

This work evaluates clinical signs, mental signs, and quality of life (QoL) after autologous adipose-derived stem cells (ADSCs) transplantation to treat acute spinal cord injury (SCI).

METHODS:

In this study, 47 SCI patients were recruited and divided into two groups: intervention and control. ADSCs were isolated and cultured under the cell culture quality control procedure. All patients in both groups underwent neurosurgery with or without ADSC transplantation. The recovery regarding neurological muscle, QoL, neurogenic bladder, and mental improvement was assessed after transplantation.

RESULTS:

All patients had improved in terms of motor function, bladder function, and daily living. No patients reported any side effect. MRI imaging showed significant changes in the lesion length of the spinal canal and the thickening of the spinal cord. Mental improvement was highest at six months after transplantation and lowest at one month after transplantation. The proportion of patients whose quality of life improved after treatment was 100%, while 80% of patients were satisfied with treatment outcomes.

CONCLUSIONS

Thus, our data suggested that ADSCs transplantation was safe and effective for the treatment of SCI patients. Neurological muscle and neurogenic bladder were improved significantly after transplantation.

Efficacy of human HC016 cell transplants on neuroprotection and functional recovery in a rat model of acute spinal cord injury

Spinal cord injury (SCI) is a devastating event with huge personal and social costs, for which there is no effective treatment. Cell therapy constitutes a promising therapeutic approach for SCI; however, its clinical potential is seriously limited by their low survival in the hostile conditions encompassing the acute phase of SCI. Human HC016 (hHC016) cells, generated from expanded human adipose mesenchymal stem cells (hAMSCs) and pulsed with a patented protocol with hydrogen peroxide (H₂ O₂ ), are expected to acquire improved resistance to oxidative environments which appears as a major limiting factor hampering the engrafting success. Our specific aim was to assess whether H₂ O₂ -pulsed hHC016 cells had an improved survival and thus therapeutic efficacy in a rat contusion model of acute SCI when grafted 48 hr after injury. Functional recovery was evaluated up to 56 days post-injury (dpi) by locomotor (open field test and CatWalk) and sensory (Von Frey and Hargreaves) tests. Besides, histological evaluation of transplanted cell survival and tissue protection/regeneration was also performed. Functional results showed a statistically significant improvement on locomotor recovery outcomes with hHC016 cells. Accordingly, superior cell survival in correlation with long-term neuroprotection, higher axonal regeneration, and reduced astroglial and microglial reactivity was also observed with hHC016 cells. These results demonstrate an enhanced survival capacity of hHC016 cells resulting in improved functional and histological outcomes as compared with hAMSCs, indicating that hHC016 cell transplants may constitute a promising cell therapy for acute SCI.

Mesenchymal stem cells and treadmill training enhance function and promote tissue preservation after spinal cord injury

Spinal cord injury (SCI) is considered a serious neurological disorder that can lead to severe sensory, motor and autonomic deficits. In this work, we investigated whether cell therapy associated with physical activity after mouse SCI could promote morphological and functional outcomes, using a lesion model established by our group. Mesenchymal stem cells (8 × 10⁵ cells/2 µL) or DMEM (2 µL), were injected in the epicenter of the lesion at 7 days after SCI, and the mice started a moderate treadmill training 14 days after injury. Functional assessments were performed weekly up to 8 weeks after injury when the morphological analyses were also performed. Four injured groups were analyzed: DMEM (SCI plus DMEM injection), MSCT (SCI plus MSC injection), DMEM + TMT (SCI plus DMEM injection and treadmill training) and MSCT + TMT (SCI plus MSC injection and treadmill training). The animals that received the combined therapy (MSCT + TMT) were able to recover and maintained the better functional results throughout the analyzed period. The morphometric analysis from MSCT + TMT group evidenced a larger spared white matter area and a higher number of preserved myelinated fibers with the majority of them reaching the ideal G-ratio values, when compared to other groups. Ultrastructural analysis from this group, using transmission electron microscopy, showed better tissue preservation with few microcavitations and degenerating nerve fibers. Also, this group exhibited a significantly higher neurotrophin 4 (NT4) expression as compared to the other groups. The results provided by this study support the conclusion that the association of strategies is a potential therapeutic approach to treat SCI, with the possibility of translation into the clinical practice.

MicroRNA-31 regulating apoptosis by mediating the phosphatidylinositol-3 kinase/protein kinase B signaling pathway in treatment of spinal cord injury

Apoptosis is a highly conservative energy demand program for non-inflammatory cell death, which is extremely significant in normal physiology and disease. There are many techniques used for studying apoptosis. MicroRNA (miRNA) is closely related to cell apoptosis, and especially microRNA-31 (miR-31) is involved in apoptosis by regulating a large number of target genes and signaling pathways. In many neurological diseases, cell apoptosis or programmed cell death plays an important role in the reduction of cell number, including the reduction of neurons in spinal cord injuries. In recent years, the phosphoinositol 3-kinase/AKT (PI3K/AKT) signal pathway, as a signal pathway involved in a variety of cell functions, has been studied in spinal cord injury diseases. The PI3K/AKT pathway directly or indirectly affects whether apoptosis occurs in a cell, thereby affecting a significant intracellular event sequence. This paper reviewed the interactions of miR-31 target sites in the PI3K/AKT signaling pathway, and explored new ways to prevent and treat spinal cord injury by regulating the effect of miR-31 on apoptosis.

In Vitro Targeting and Imaging of Neurogenic Differentiation in Mouse Bone-Marrow Derived Mesenchymal Stem Cells with Superparamagnetic Iron Oxide Nanoparticles

Spinal cord injuries (SCI) are well thought to be a crucial issue that roots various side effects for a patient during their entire lifetime. Although therapeutical methods to resolve the SCI are limited, stem cell therapy is determined to be a resolving factor since it possesses the ability to induce the neurogenic differentiation and the paracrine effect. However, stem cells are difficult to inject directly into the lesion, so they must be carefully guided through the spinal canal. Therefore, superparamagnetic iron oxide nanoparticles (SPIONs) are introduced as an instigator that makes the cells respond to the applied magnetic field. This study intends to report the synthesis strategy to develop SPIONs that could be used to treat the injury site by an applied magnetic field. SPION-internalized D1 Mesenchymal stem cells (MSCs) are observed consistently using a confocal fluorescence microscope to analyze the toxicity, maintenance, and monitoring points of intracellular SPIONs. The prepared SPIONs are much anticipated to increase the migration efficiency using magnetism, which was not cytotoxic. Hence, the prepared SPIONs can adeptly target the damaged neural tissue to promote tissue regeneration and treat nervous system disorders. This primary study stands as a focal point to solve SCI by stem cell migration effectively.

Crosstalk between stem cell and spinal cord injury: pathophysiology and treatment strategies

The injured spinal cord is difficult to repair and regenerate. Traditional treatments are not effective. Stem cells are a type of cells that have the potential to differentiate into various cells, including neurons. They exert a therapeutic effect by safely and effectively differentiating into neurons or replacing damaged cells, secreting neurotrophic factors, and inhibiting the inflammatory response. Many types of stem cells have been used for transplantation, and each has its own advantages and disadvantages. This review discusses the possible mechanisms of stem cell therapy for spinal cord injury, and the types of stem cells commonly used in experiments, to provide a reference for basic and clinical research on stem cell therapy for spinal cord injury.

Magnetic Composite Biomaterials for Neural Regeneration

Nervous system damage caused by physical trauma or degenerative diseases can result in loss of sensory and motor function for patients. Biomaterial interventions have shown promise in animal studies, providing contact guidance for extending neurites or sustained release of various drugs and growth factors; however, these approaches often target only one aspect of the regeneration process. More recent studies investigate hybrid approaches, creating complex materials that can reduce inflammation or provide neuroprotection in addition to stimulating growth and regeneration. Magnetic materials have shown promise in this field, as they can be manipulated non-invasively, are easily functionalized, and can be used to mechanically stimulate cells. By combining different types of biomaterials (hydrogels, nanoparticles, electrospun fibers) and incorporating magnetic elements, magnetic materials can provide multiple physical and chemical cues to promote regeneration. This review, for the first time, will provide an overview of design strategies for promoting regeneration after neural injury with magnetic biomaterials.

Human gingival mesenchymal stem cells pretreated with vesicular moringin nanostructures as a new therapeutic approach in a mouse model of spinal cord injury

Spinal cord injury (SCI) is a neurological disorder that arises from a primary acute mechanical lesion, followed by a pathophysiological cascade of events that leads to further spinal cord tissue damage. Several preclinical and clinical studies have highlighted the ability of stem cell therapy to improve long-term functional recovery in SCI. Previously, we demonstrated that moringin (MOR) treatment accelerates the differentiation process in mesenchymal stem cells inducing an early up-regulation of neural development associated genes. In the present study, we investigated the anti-inflammatory, anti-apoptotic, and regenerative effects of gingival mesenchymal stem cells (GMSCs) pretreated with nanostructured liposomes enriched with MOR in an animal model of SCI. SCI was produced by extradural compression of the spinal cord at levels T6-T7 in ICR (CD-1) mice. Animals were randomly assigned to the following groups: Sham, SCI, SCI + GMSCs (1 × 106  cell/i.v.), SCI + MOR-GMSCs (1 × 106  cell/i.v.). Our data show that MOR-treated GMSCs exert anti-inflammatory and anti-apoptotic activities. In particular, MOR-treated GMSCs are able to reduce the spinal cord levels of COX-2, GFAP, and inflammatory cytokines IL-1β and IL-6 and to restore spinal cord normal morphology. Also, MOR-treated GMSCs influenced the apoptotic pathway, by reducing Bax, caspase 3, and caspase 9 expressions.

Mesenchymal Stem Cells for Spinal Cord Injury: Current Options, Limitations, and Future of Cell Therapy

Spinal cord injury (SCI) constitutes an inestimable public health issue. The most crucial phase in the pathophysiological process of SCI concerns the well-known secondary injury, which is the uncontrolled and destructive cascade occurring later with aberrant molecular signaling, inflammation, vascular changes, and secondary cellular dysfunctions. The use of mesenchymal stem cells (MSCs) represents one of the most important and promising tested strategies. Their appeal, among the other sources and types of stem cells, increased because of their ease of isolation/preservation and their properties. Nevertheless, encouraging promise from preclinical studies was followed by weak and conflicting results in clinical trials. In this review, the therapeutic role of MSCs is discussed, together with their properties, application, limitations, and future perspectives.

Different functional bio-scaffolds share similar neurological mechanism to promote locomotor recovery of canines with complete spinal cord injury

Many studies have shown that rodents exhibit a certain degree of spontaneous motor function recovery even if they suffer from spinal cord complete transection injury. However, the characteristics of spontaneous locomotor recovery and its associated neurobiological mechanisms are unclear. In this study, we observed that spontaneous locomotor function recovery of hind limbs could also be detected in a canine thoracic (T8) spinal cord complete transection model. In addition, the spontaneous locomotor recovery of canines could be further promoted by chronic implantation of Taxol- or human bone marrow mesenchymal stem cell-modified bio-scaffolds. Moreover, functional bio-scaffolds implantation promoted locomotor outcome could be significantly weakened (drop to the spontaneous recovery level) but not totally abolished by resection in the lesion site. The neurological mechanism for functional bio-scaffolds improved locomotor outcome was primarily dependent on the formation of neuronal bridging but not the long-distance regeneration of descending motor axons throughout the lesion gap. Besides that, we found that spontaneously achieved locomotor recovery of hind limbs was unable to be weaken by repetitive resection of the lesion area, indicating the mechanism for spontaneous locomotor recovery was independent on functional neurological bridging throughout the lesion gap.

Spinal cord injury: pathophysiology, treatment strategies, associated challenges, and future implications

Axonal regeneration and formation of tripartite (axo-glial) junctions at damaged sites is a prerequisite for early repair of injured spinal cord. Transplantation of stem cells at such sites of damage which can generate both neuronal and glial population has gained impact in terms of recuperation upon infliction with spinal cord injury. In spite of the fact that a copious number of pre-clinical studies using different stem/progenitor cells have shown promising results at acute and subacute stages, at the chronic stages of injury their recovery rates have shown a drastic decline. Therefore, developing novel therapeutic strategies are the need of the hour in order to assuage secondary morbidity and effectuate improvement of the spinal cord injury (SCI)-afflicted patients' quality of life. The present review aims at providing an overview of the current treatment strategies and also gives an insight into the potential cell-based therapies for the treatment of SCI.

Chitosan-based hydrogel to support the paracrine activity of mesenchymal stem cells in spinal cord injury treatment

Advanced therapies which combine cells with biomaterial-based carriers are recognized as an emerging and powerful method to treat challenging diseases, such as spinal cord injury (SCI). By enhancing transplanted cell survival and grafting, biomimetic hydrogels can be properly engineered to encapsulate cells and locate them at the injured site in a minimally invasive way. In this work, chitosan (CS) based hydrogels were developed to host mesenchymal stem cells (MSCs), since their paracrine action can therapeutically enhance the SC regeneration, limiting the formation of a glial scar and reducing cell death at the injured site. An injectable and highly permeable CS-based hydrogel was fabricated having a rapid gelation upon temperature increase from 0 to 37 °C. CS was selected as former material both for its high biocompatibility that guarantees the proper environment for MSCs survival and for its ability to provide anti-inflammatory and anti-oxidant cues. MSCs were mixed with the hydrogel solution prior to gelation. MSC viability was not affected by the CS hydrogel and encapsulated MSCs were able to release MSC-vesicles as well as to maintain their anti-oxidant features. Finally, preliminary in vivo tests on SCI mice revealed good handling of the CS solution loading MSCs during implantation and high encapsulated MSCs survival after 7 days.

Stem cell paracrine effect and delivery strategies for spinal cord injury regeneration

Spinal cord injury (SCI) is a complicated neuropathological condition that results in functional dysfunction and paralysis. Various treatments have been proposed including drugs, biological factors and cells administered in several ways. Stem cell therapy offers a potentially revolutionary mode to repair the damaged spinal cord after injury. Initially, stem cells were considered promising for replacing cells and tissue lost after SCI. Many studies looked at their differentiation to replace neuronal and glial cells for a better functional outcome. However, it is becoming clear that different functional improvements recognized to stem cells are due to biomolecular activities by the transplanted stem cells rather than cell replacement. This review aimed to discuss the paracrine mechanisms for tissue repair and regeneration after stem cell transplantation in SCI. It focuses on stem cell factor production, effect in tissue restoration, and novel delivery strategies to use them for SCI therapy.

Time is spine: a review of translational advances in spinal cord injury

Acute traumatic spinal cord injury (SCI) is a devastating event with far-reaching physical, emotional, and economic consequences for patients, families, and society at large. Timely delivery of specialized care has reduced mortality; however, long-term neurological recovery continues to be limited. In recent years, a number of exciting neuroprotective and regenerative strategies have emerged and have come under active investigation in clinical trials, and several more are coming down the translational pipeline. Among ongoing trials are RISCIS (riluzole), INSPIRE (Neuro-Spinal Scaffold), MASC (minocycline), and SPRING (VX-210). Microstructural MRI techniques have improved our ability to image the injured spinal cord at high resolution. This innovation, combined with serum and cerebrospinal fluid (CSF) analysis, holds the promise of providing a quantitative biomarker readout of spinal cord neural tissue injury, which may improve prognostication and facilitate stratification of patients for enrollment into clinical trials. Given evidence of the effectiveness of early surgical decompression and growing recognition of the concept that "time is spine," infrastructural changes at a systems level are being implemented in many regions around the world to provide a streamlined process for transfer of patients with acute SCI to a specialized unit. With the continued aging of the population, central cord syndrome is soon expected to become the most common form of acute traumatic SCI; characterization of the pathophysiology, natural history, and optimal treatment of these injuries is hence a key public health priority. Collaborative international efforts have led to the development of clinical practice guidelines for traumatic SCI based on robust evaluation of current evidence. The current article provides an in-depth review of progress in SCI, covering the above areas.

Spinal cord injury pharmacotherapy: Current research & development and competitive commercial landscape as of 2015

CONTEXT

Current treatment of spinal cord injury (SCI) focuses on cord stabilization to prevent further injury, rehabilitation, management of non-motor symptoms, and prevention of complications. Currently, no approved treatments are available, and limited treatment options exist for symptoms and complications associated with chronic SCI. This review describes the pharmacotherapy landscape in SCI from both commercial and research and development (R&D) standpoints through March 2015.

METHODS

Information about specific compounds has been obtained through drug pipeline monographs in the Pharmaprojects® (Citeline, Inc., New York, New York, USA) drug database (current as of a search on May 30, 2014), websites of individual companies with compounds in development for SCI (current as of March 24, 2015), and a literature search of published R&D studies to validate the Pharmaprojects® source for selected compounds (current as of March 24, 2015).

RESULTS

Types of studies conducted and outcomes measured in earlier phases of development are described for compounds in clinical development Currently four primary mechanisms are under investigation and may yield promising therapeutic targets: 1) neuronal regeneration; 2) neuroprotection (including anti-inflammation); 3) axonal reconnection; and 4) neuromodulation and signal enhancement. Many other compounds are no longer under investigation for SCI are mentioned; however, in most cases, the reason for terminating their development is not clear.

CONCLUSION

There is urgent need to develop disease-modifying therapy for SCI, yet the commercial landscape remains small and highly fragmented with a paucity of novel late-stage compounds in R&D.

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.

Modeling biological and economic uncertainty on cell therapy manufacturing: the choice of culture media supplementation

AIM

To evaluate the cost-effectiveness of autologous cell therapy manufacturing in xeno-free conditions.

MATERIALS & METHODS

Published data on the isolation and expansion of mesenchymal stem/stromal cells introduced donor, multipassage and culture media variability on cell yields and process times on adherent culture flasks to drive cost simulation of a scale-out campaign of 1000 doses of 75 million cells each in a 400 square meter Good Manufacturing Practices facility.

RESULTS & CONCLUSION

Passage numbers in the expansion step are strongly associated with isolation cell yield and drive cost increases per donor of $1970 and 2802 for fetal bovine serum and human platelet lysate. Human platelet lysate decreases passage numbers and process costs in 94.5 and 97% of donors through lower facility and labor costs. Cost savings are maintained with full equipment depreciation and higher numbers of cells per dose, highlighting the number of cells per passage step as the key cost driver.

Adipose-derived stem cells alleviate liver apoptosis induced by ischemia-reperfusion and laparoscopic hepatectomy in swine

Hepatic ischemia-reperfusion (I/R) injury is inevitable during hepatectomy and may cause both postoperative morbidity and mortality. Regenerative medicine suggested adipose-derived stem cells (ADSCs) as an attractive tool for the treatment of liver diseases. In this study, we investigated the effect of ADSCs in an I/R model combined with laparoscopic hepatectomy in swine. Eighteen Bama miniature pigs were randomly divided into Sham, IRI, and ADSCs groups. ADSCs (1 × 106/kg) were injected through liver parenchyma immediately after hemihepatectomy. The apoptosis-related role of ADSCs was studied. The results showed that ADSCs transplantation reduced both pathological and ultrastructural changes and decreased the number of apoptotic-positive cells. In the ADSCs group, Fas, Fas ligand (FasL) protein, and mRNA were downregulated and the enzyme activities of Caspase3, Caspase8, and Caspase9 were significantly decreased. In addition, ADSC therapy significantly increased the ratio of Bcl-2/Bax protein and mRNA compared to the IRI group. In conclusion, ADSCs attenuated both I/R and hepatectomy-induced liver apoptosis in a porcine model, and offers a potential therapeutic option for hepatic I/R and hepatectomy.

Combined effects of rat Schwann cells and 17β-estradiol in a spinal cord injury model

Spinal cord injury (SCI) is a devastating traumatic event which burdens the affected individuals and the health system. Schwann cell (SC) transplantation is a promising repair strategy after SCI. However, a large number of SCs do not survive following transplantation. Previous studies demonstrated that 17β-estradiol (E2) protects different cell types and reduces tissue damage in SCI experimental animal model. In the current study, we evaluated the protective potential of E2 on SCs in vitro and investigated whether the combination of hormonal and SC therapeutic strategy has a better effect on the outcome after SCI. Primary SC cultures were incubated with E2 for 72 h. In a subsequent experiment, thoracic contusion SCI was induced in male rats followed by sustained administration of E2 or vehicle. Eight days after SCI, DiI-labeled SCs were transplanted into the injury epicenter in vehicle and E2-treated animals. The combinatory regimen decreased neurological and behavioral deficits and protected neurons and oligodendrocytes in comparison to vehicle rats. Moreover, E2 and SC significantly decreased the number of Iba-1+ (microglia) and GFAP⁺ cells (astrocyte) in the SCI group. In addition, we found a significant reduction of mitochondrial fission-markers (Fis1) and an increase of fusion-markers (Mfn1 and Mfn2) in the injured spinal cord after E2 and SC treatment. These data demonstrated that E2 protects SCs against hypoxia-induced SCI and improves the survival of transplanted SCs.

Isolation of Adipose-Derived Stem/Stromal Cells from Cryopreserved Fat Tissue and Transplantation into Rats with Spinal Cord Injury

Adipose tissue contains multipotent cells known as adipose-derived stem/stromal cells (ASCs), which have therapeutic potential for various diseases. Although the demand for adipose tissue for research use remains high, no adipose tissue bank exists. In this study, we attempted to isolate ASCs from cryopreserved adipose tissue with the aim of developing a banking system. ASCs were isolated from fresh and cryopreserved adipose tissue of rats and compared for proliferation (doubling time), differentiation capability (adipocytes), and cytokine (hepatocyte growth factor and vascular endothelial growth factor) secretion. Finally, ASCs (2.5 × 10⁶) were intravenously infused into rats with spinal cord injury, after which hindlimb motor function was evaluated. Isolation and culture of ASCs from cryopreserved adipose tissue were possible, and their characteristics were not significantly different from those of fresh tissue. Transplantation of ASCs derived from cryopreserved tissue significantly promoted restoration of hindlimb movement function in injured model rats. These results indicate that cryopreservation of adipose tissue may be an option for clinical application.

Migration of mesenchymal stem cells to tumor xenograft models and in vitro drug delivery by doxorubicin

Mesenchymal stem cells (MSCs) show therapeutic effects in various types of diseases. MSCs have been shown to migrate towards inflamed or cancerous tissues, and visualized after sacrificing the animal. MSCs are able to deliver drugs to target cells, and are an ideal candidate for cancer therapy. The purpose of this study was to track the migration of MSCs in tumor-bearing mice; MSCs were also used as drug delivery vehicles. Human breast cancer cells (MDA-MB-231) and anaplastic thyroid cancer cells (CAL62) were transduced with lentiviral particles, to express the Renilla luciferase and mCherry (mCherry-Rluc) reporter genes. Human bone marrow-derived MSCs were transduced with lentiviral particles, to express the firefly luciferase and enhanced green fluorescence protein (Fluc2-eGFP) reporter genes (MSC/Fluc). Luciferase activity of the transduced cells was measured by bioluminescence imaging (BLI). Further in vitro migration assays were performed to confirm cancer cells conditioned medium dependent MSC and doxorubicin (DOX) treated MSC migration. MSCs were loaded with DOX, and their therapeutic effects against the cancer cells were studied in vitro. In vivo MSC/Fluc migration in mice having thyroid or breast cancer xenografts was evaluated after systemic injection. Rluc activity of CAL62/Rluc (R2=0.911), MDA-MB-231/Rluc (R2=0.934) cells and Fluc activity of MSC/Fluc (R2=0.91) cells increased with increasing cell numbers, as seen by BLI. eGFP expression of MSC/Fluc was confirmed by confocal microscopy. Similar migration potential was observed between MSC/Fluc and naïve MSCs in migration assay. DOX treated MSCs migration was not decreased compared than MSCs. Migration of the systemically injected MSC/Fluc cells into tumor xenografts (thyroid and breast cancer) was visualized in animal models (p<0.05) and confirmed by ex vivo (p<0.05) BLI. Additionally, MSCs delivered DOX to CAL62/Rluc and MDA-MB-231/Rluc cells, thereby decreasing their Rluc activities. In this study, we confirmed the migration of MSCs to tumor sites in cancer xenograft models using both in vivo and ex vivo BLI imaging. DOX-pretreated MSCs showed enhanced cytotoxic effects. Therefore, this noninvasive reporter gene (Fluc2)-based BLI may be useful for visualizing in vivo tracking of MSCs, which can be used as a drug delivery vehicle for cancer therapy.

Improved Healing after the Co-Transplantation of HO-1 and BDNF Overexpressed Mesenchymal Stem Cells in the Subacute Spinal Cord Injury of Dogs

Abundant expression of proinflammatory cytokines after a spinal cord injury (SCI) creates an inhibitory microenvironment for neuroregeneration. The mesenchymal stem cells help to mitigate the inflammation and improve neural growth and survival. For this purpose, we potentiated the function of adipose-derived mesenchymal stem cells (Ad-MSCs) by transfecting them with brain-derived neurotrophic factor (BDNF) and heme oxygenase-1 (HO-1), through a lentivirus, to produce BDNF overexpressed Ad-MSCs (BDNF-MSCs), and HO-1 overexpressed Ad-MSCs (HO-1-MSCs). Sixteen SCI beagle dogs were randomly assigned into four treatment groups. We injected both HO-1 and BDNF-overexpressed MSCs as a combination group, to selectively control inflammation and induce neuroregeneration in SCI dogs, and compared this with BDNF-MSCs, HO-1-MSCs, and GFP-MSCs injected dogs. The groups were compared in terms of improvement in canine Basso, Beattie, and Bresnahan (cBBB) score during 8 weeks of experimentation. After 8 weeks, spinal cords were harvested and subjected to western blot analysis, immunofluorescent staining, and hematoxylin and eosin (H&E) staining. The combination group showed a significant improvement in hindlimb functions, with a higher BBB score, and a robust increase in neuroregeneration, depicted by a higher expression of Tuj-1, NF-M, and GAP-43 due to a decreased expression of the inflammatory markers interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), and an increased expression of interleukin-10 (IL-10) (P ≤ 0.05). H&E staining showed more reduced intraparenchymal fibrosis in the combination group than in other groups (P ≤ 0.05). It was thus suggested that the cotransplantation of HO-1 and BDNF-MSCs is more effective in promoting the healing of SCI. HO-1-MSCs reduce inflammation, which favors BDNF-induced neuroregeneration in SCI of dogs.

Calcium: A novel and efficient inducer of differentiation of adipose-derived stem cells into neuron-like cells

This study comparatively investigated the effectiveness of calcium and other well-known inducers such as isobutylmethylxanthine (IBMX) and insulin in differentiating human adipose-derived stem cells (ADSCs) into neuronal-like cells. ADSCs were immunophenotyped and differentiated into neuron-like cells with different combinations of calcium, IBMX, and insulin. Calcium mobilization across the membrane was determined. Differentiated cells were characterized by cell cycle profiling, staining of Nissl bodies, detecting the gene expression level of markers such as neuronal nuclear antigen (NeuN), microtubule associated protein 2 (MAP2), neuron-specific enolase (NSE), doublecortin, synapsin I, glial fibrillary acidic protein (GFAP), and myelin basic protein (MBP) by quantitative real-time polymerase chain reaction (quantitative real-time polymerase chain reaction (qRT-PCR) and protein level by the immunofluorescence technique. Treatment with Ca + IBMX + Ins induced neuronal appearance and projection of neurite-like processes in the cells, accompanied with inhibition of proliferation and halt in the cell cycle. A significantly higher expression of MBP, GFAP, NeuN, NSE, synapsin 1, doublecortin, and MAP2 was detected in differentiated cells, confirming the advantages of Ca + IBMX + Ins to the other combinations of inducers. Here, we showed an efficient protocol for neuronal differentiation of ADSCs, and calcium fostered differentiation by augmenting the number of neuron-like cells and instantaneous increase in the expression of neuronal markers.