Bone marrow stromal cells can achieve cure of chronic paraplegic rats: Functional and morphological outcome one year after transplantation

Bone marrow mesenchymal stem cells in treatment of peripheral nerve injury

Peripheral nerve injury (PNI) is a common neurological disorder and complete functional recovery is difficult to achieve. In recent years, bone marrow mesenchymal stem cells (BMSCs) have emerged as ideal seed cells for PNI treatment due to their strong differentiation potential and autologous transplantation ability. This review aims to summarize the molecular mechanisms by which BMSCs mediate nerve repair in PNI. The key mechanisms discussed include the differentiation of BMSCs into multiple types of nerve cells to promote repair of nerve injury. BMSCs also create a microenvironment suitable for neuronal survival and regeneration through the secretion of neurotrophic factors, extracellular matrix molecules, and adhesion molecules. Additionally, BMSCs release pro-angiogenic factors to promote the formation of new blood vessels. They modulate cytokine expression and regulate macrophage polarization, leading to immunomodulation. Furthermore, BMSCs synthesize and release proteins related to myelin sheath formation and axonal regeneration, thereby promoting neuronal repair and regeneration. Moreover, this review explores methods of applying BMSCs in PNI treatment, including direct cell transplantation into the injured neural tissue, implantation of BMSCs into nerve conduits providing support, and the application of genetically modified BMSCs, among others. These findings confirm the potential of BMSCs in treating PNI. However, with the development of this field, it is crucial to address issues related to BMSC therapy, including establishing standards for extracting, identifying, and cultivating BMSCs, as well as selecting application methods for BMSCs in PNI such as direct transplantation, tissue engineering, and genetic engineering. Addressing these issues will help translate current preclinical research results into clinical practice, providing new and effective treatment strategies for patients with PNI.

Shock wave and mesenchymal stem cells as treatment in the acute phase of spinal cord injury: A pilot study

INTRODUCTION

Spinal cord injury (SCI) is a complex pathology with thousands of patients worldwide. During the acute early phase, neural tissue shows some regenerative properties that disappear at the chronic phase. Shock Waves and Stem Cells have been proposed as a possible therapy.

METHODS

Here, we analyse Shock Waves' immediate effect over spinal cord genetic response in the injured and healthy spinal cord and the effect of Shock Waves and combined Shock Waves plus Stem Cells distally grafted to treat the first month after spinal cord injury.

RESULTS

The immediate application of shock waves increases VEGF (Vascular Endothelial Growth Factor) but reduces the BDNF (Brain-Derived Growth Factor) RNA (Ribonucleic acid) response. Shock wave therapy increases GFAP (Glial fibrillary acidic protein) positive cells and vascularity during the treatment's acute phase.

CONCLUSION

Shock wave treatment seems to be enough to produce benefits in the acute phase of spinal cord injury, with no accumulative positive effects when mesenchymal stem cell graft is applied together.

Mesenchymal Stem Cell Applications in Spine Disorders: A Comprehensive Review

Mesenchymal stem cells (MSCs) are increasingly being employed in a number of orthopedic settings, in particular in the treatment of hip and knee osteoarthritis. Recently, the use MSCs has been investigated for different spine settings. However, the use of these cells is not yet widespread in the clinical practice. The aim of this review was to investigate the current literature regarding the use of MSCs in different spine conditions and discuss possible future applications. In particular, degenerative disc disease is the most studied field for MSC application, and is the only one that has already reached the clinical practice, albeit not routinely. Spinal cord injuries are another extensively investigated use of MSCs: despite encouraging preliminary results, a consensus on the efficacy of stem cell therapy for spinal cord injuries has not yet been reached, and their use is still only experimental.

Cell-Based Therapies for Traumatic Brain Injury: Therapeutic Treatments and Clinical Trials

Traumatic brain injury (TBI) represents physical damage to the brain tissue that induces transitory or permanent neurological disabilities. TBI contributes to 50% of all trauma deaths, with many enduring long-term consequences and significant medical and rehabilitation costs. There is currently no therapy to reverse the effects associated with TBI. An increasing amount of research has been undertaken regarding the use of different stem cells (SCs) to treat the consequences of brain damage. Neural stem cells (NSCs) (adult and embryonic) and mesenchymal stromal cells (MSCs) have shown efficacy in pre-clinical models of TBI and in their introduction to clinical research. The purpose of this review is to provide an overview of TBI and the state of clinical trials aimed at evaluating the use of stem cell-based therapies in TBI. The primary aim of these studies is to investigate the safety and efficacy of the use of SCs to treat this disease. Although an increasing number of studies are being carried out, few results are currently available. In addition, we present our research regarding the use of cell therapy in TBI. There is still a significant lack of understanding regarding the cell therapy mechanisms for the treatment of TBI. Thus, future studies are needed to evaluate the feasibility of the transplantation of SCs in TBI.

The Effect of Transplantation of Olfactory Ensheathing Cells on the Size of Posttraumatic Spinal Cord Cysts

We studied the effect of transplantation of ensheathing cells obtained from the olfactory mucosa of rats and humans on the size of posttraumatic spinal cord cysts. MRI examination showed that transplantation of these cells into experimental posttraumatic cysts of the spinal cord led to a significant decrease in cyst volume and even their complete disappearance in two animals receiving transplantation of rat or human cells. These findings attested to regenerative processes developing as a result of ensheathing cell transplantation. Further studies in this field will be aimed at elucidation of the mechanisms underlying spinal cord regeneration in the area of posttraumatic cysts after transplantation of ensheathing cells.

Biomimetic Hybrid Systems for Tissue Engineering

Tissue engineering approaches appear nowadays highly promising for the regeneration of injured/diseased tissues. Biomimetic scaffolds are continuously been developed to act as structural support for cell growth and proliferation as well as for the delivery of cells able to be differentiated, and also of bioactive molecules like growth factors and even signaling cues. The current research concerns materials employed to develop biological scaffolds with improved features as well as complex preparation techniques. In this work, hybrid systems based on natural polymers are discussed and the efforts focused to provide new polymers able to mimic proteins and DNA are extensively explained. Progress on the scaffold fabrication technique is mentioned, those processes based on solution and melt electrospinning or even on their combination being mainly discussed. Selection of the appropriate hybrid technology becomes vital to get optimal architecture to reasonably accomplish the final applications. Representative examples of the recent possibilities on tissue regeneration are finally given.

Three-dimensional bioprinting collagen/silk fibroin scaffold combined with neural stem cells promotes nerve regeneration after spinal cord injury

Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal cord. Indeed, cell transplantation and bio-scaffold implantation are considered to be effective methods for neural regeneration. This study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3D-CF) with cavities that simulate the anatomy of normal spinal cord. This scaffold allows cell growth in vitro and in vivo. To observe the effects of combined transplantation of neural stem cells (NSCs) and 3D-CF on the repair of spinal cord injury. Forty Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed), spinal cord injury (transection injury of T10 spinal cord without any transplantation), 3D-CF (3D scaffold was transplanted into the local injured cavity), and 3D-CF + NSCs (3D scaffold co-cultured with NSCs was transplanted into the local injured cavity. Neuroelectrophysiology, imaging, hematoxylin-eosin staining, argentaffin staining, immunofluorescence staining, and western blot assay were performed. Apart from the sham group, neurological scores were significantly higher in the 3D-CF + NSCs group compared with other groups. Moreover, latency of the 3D-CF + NSCs group was significantly reduced, while the amplitude was significantly increased in motor evoked potential tests. The results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3D-CF + NSCs group. Moreover, regenerative axons were abundant and glial scarring was reduced in the 3D-CF + NSCs group compared with other groups. These results confirm that implantation of 3D-CF combined with NSCs can promote the repair of injured spinal cord. This study was approved by the Institutional Animal Care and Use Committee of People's Armed Police Force Medical Center in 2017 (approval No. 2017-0007.2).

Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury

Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti-apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried (1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation; (2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI; (3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy.

Human Oligodendrogenic Neural Progenitor Cells Delivered with Chondroitinase ABC Facilitate Functional Repair of Chronic Spinal Cord Injury

Treatment of chronic spinal cord injury (SCI) is challenging due to cell loss, cyst formation, and the glial scar. Previously, we reported on the therapeutic potential of a neural progenitor cell (NPC) and chondroitinase ABC (ChABC) combinatorial therapy for chronic SCI. However, the source of NPCs and delivery system required for ChABC remained barriers to clinical application. Here, we investigated directly reprogrammed human NPCs biased toward an oligodendrogenic fate (oNPCs) in combination with sustained delivery of ChABC using an innovative affinity release strategy in a crosslinked methylcellulose biomaterial for the treatment of chronic SCI in an immunodeficient rat model. This combinatorial therapy increased long-term survival of oNPCs around the lesion epicenter, facilitated greater oligodendrocyte differentiation, remyelination of the spared axons by engrafted oNPCs, enhanced synaptic connectivity with anterior horn cells and neurobehavioral recovery. This combinatorial therapy is a promising strategy to regenerate the chronically injured spinal cord.

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Sustained biomaterial delivery of ChABC successfully degraded CSPGs

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XMC-ChABC promoted differentiation of oNPCs to more oligodendrocytes

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XMC-ChABC increased the long-term survival and integration of grafted oNPCs

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XMC-ChABC and oNPC combinatorial therapy is a promising treatment for chronic SCI

Evaluation of the Safety and Efficacy of the Therapeutic Potential of Adipose-Derived Stem Cells Injected in the Cerebral Ischemic Penumbra

INTRODUCTION

Stroke represents an attractive target for cell therapy. Although different types of cells have been employed in animal models with variable results, the human adipose-derived stem cells (hASCs) have demonstrated favorable characteristics in the treatment of diseases with inflammatory substrate, but experience in their intracerebral administration is lacking. The purpose of this study is to evaluate the effect and safety of the intracerebral application of hASCs in a stroke model.

METHODS

A first group of Athymic Nude mice after stroke received a stereotactic injection of hASCs at a concentration of 4 × 10⁴/µL at the penumbra area, a second group without stroke received the same cell concentration, and a third group had only stroke and no cells. After 7, 15, and 30 days, the animals underwent fluorodeoxyglucose-positron emission tomography and magnetic resonance imaging; subsequently, they were sacrificed for histological evaluation (HuNu, GFAP, IBA-1, Ki67, DCX) of the penumbra area and ipsilateral subventricular zone (iSVZ).

RESULTS

The in vitro studies found no alterations in the molecular karyotype, clonogenic capacity, and expression of 62 kDa transcription factor and telomerase. Animals implanted with cells showed no adverse events. The implanted cells showed no evidence of proliferation or differentiation. However, there was an increase of capillaries, less astrocytes and microglia, and increased bromodeoxyuridine and doublecortin-positive cells in the iSVZ and in the vicinity of ischemic injury.

CONCLUSIONS

These results suggest that hASCs in the implanted dose modulate inflammation, promote endogenous neurogenesis, and do not proliferate or migrate in the brain. These data confirm the safety of cell therapy with hASCs.

Cell therapy for spinal cord injury with olfactory ensheathing glia cells (OECs)

The prospects of achieving regeneration in the central nervous system (CNS) have changed, as most recent findings indicate that several species, including humans, can produce neurons in adulthood. Studies targeting this property may be considered as potential therapeutic strategies to respond to injury or the effects of demyelinating diseases in the CNS. While CNS trauma may interrupt the axonal tracts that connect neurons with their targets, some neurons remain alive, as seen in optic nerve and spinal cord (SC) injuries (SCIs). The devastating consequences of SCIs are due to the immediate and significant disruption of the ascending and descending spinal pathways, which result in varying degrees of motor and sensory impairment. Recent therapeutic studies for SCI have focused on cell transplantation in animal models, using cells capable of inducing axon regeneration like Schwann cells (SchCs), astrocytes, genetically modified fibroblasts and olfactory ensheathing glia cells (OECs). Nevertheless, and despite the improvements in such cell-based therapeutic strategies, there is still little information regarding the mechanisms underlying the success of transplantation and regarding any secondary effects. Therefore, further studies are needed to clarify these issues. In this review, we highlight the properties of OECs that make them suitable to achieve neuroplasticity/neuroregeneration in SCI. OECs can interact with the glial scar, stimulate angiogenesis, axon outgrowth and remyelination, improving functional outcomes following lesion. Furthermore, we present evidence of the utility of cell therapy with OECs to treat SCI, both from animal models and clinical studies performed on SCI patients, providing promising results for future treatments.

Platelet-rich plasma-derived scaffolds increase the benefit of delayed mesenchymal stromal cell therapy after severe traumatic brain injury

BACKGROUND

Cell therapy using mesenchymal stromal cells (MSCs) offers new perspectives in the treatment of traumatic brain injury (TBI). The aim of the present study was to assess the impact of platelet-rich plasma scaffolds (PRPS) as support of MSCs in a delayed phase after severe TBI in rats.

METHODS

TBI was produced by weight-drop impact to the right cerebral hemisphere. Two months after TBI, four experimental groups were established; saline, PRPS, MSCs in saline, or MSCs in PRPS was transplanted into the area of brain lesion through a small hole. All groups were evaluated in the course of the following 12 months after therapy and the animals were then humanely killed.

RESULTS

Our results showed that a greater functional improvement was obtained after the administration of MSCs in PRPS compared with the other experimental groups.

DISCUSSION

PRPS enhanced the benefit of cell therapy with MSCs to treat chronic brain damage in rats that suffered a severe TBI. The present findings suggest that the use of intralesional MSCs supported in PRPS may be a strategy of tissue engineering for patients with established neurological severe dysfunction after a TBI.

Stem Cell and Advanced Nano Bioceramic Interactions

Bioceramics are type of biomaterials generally used for orthopaedic applications due to their similar structure with bone. Especially regarding to their osteoinductivity and osteoconductivity, they are used as biodegradable scaffolds for bone regeneration along with mesenchymal stem cells. Since chemical properties of bioceramics are important for regeneration of tissue, physical properties are also important for cell proliferation. In this respect, several different manufacturing methods are used for manufacturing nano scale bioceramics. These nano scale bioceramics are used for regeneration of bone and cartilage both alone or with other types of biomaterials. They can also act as carrier for the delivery of drugs in musculoskeletal infections without causing any systemic toxicity.

Efficacy of chitosan and sodium alginate scaffolds for repair of spinal cord injury in rats

Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental rats. Sixty days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells (regenerating nerve fibers) and less glial fibrillary acidic protein-immunoreactive cells (astrocytic scar tissue) were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue, and as such, is more suitable to help the repair of spinal cord injury.

Improved stem cell therapy of spinal cord injury using GDNF-overexpressed bone marrow stem cells in a rat model

The use of stem cell base therapy as an effective strategy for the treatment of spinal cord injury (SCI) is very promising. Although some strategy has been made to generate neural-like cells using bone marrow mesenchymal stem cells (BMSCs), the differentiation strategies are still inefficiently. For this purpose, we improved the therapeutic outcome with utilize both of N-neurotrophic factor derived Gelial cells (GDNF) gene and differentiation medium that induce the BMSCs into the neural-like cells. The differentiated GDNF overexpressed BMSCs (BMSCs-GDNF) were injected on the third day of post-SCI. BBB score test was performed for four weeks. Two weeks before the end of BBB, biotin dextranamin was injected intracrebrally and at the end of the fourth week, the tissue was stained. BBB scores were significantly different in BMSCs-GDNF injected and control animals. Significant difference in axon counting was observed in BMSCs-GDNF treated animals compared to the control group. According to the results, differentiated BMSCs-GDNF showed better results in comparison to the BMSCs without genetic modification. This study provides a new strategy to investigate the role of simultaneous in stem cell and gene therapy for future neural-like cells transplantation base therapies for SCI.

Combinatory repair strategy to promote axon regeneration and functional recovery after chronic spinal cord injury

Eight weeks post contusive spinal cord injury, we built a peripheral nerve graft bridge (PNG) through the cystic cavity and treated the graft/host interface with acidic fibroblast growth factor (aFGF) and chondroitinase ABC (ChABC). This combinatorial strategy remarkably enhanced integration between host astrocytes and graft Schwann cells, allowing for robust growth, especially of catecholaminergic axons, through the graft and back into the distal spinal cord. In the absence of aFGF+ChABC fewer catecholaminergic axons entered the graft, no axons exited, and Schwann cells and astrocytes failed to integrate. In sharp contrast with the acutely bridge-repaired cord, in the chronically repaired cord only low levels of serotonergic axons regenerated into the graft, with no evidence of re-entry back into the spinal cord. The failure of axons to regenerate was strongly correlated with a dramatic increase of SOCS3 expression. While regeneration was more limited overall than at acute stages, our combinatorial strategy in the chronically injured animals prevented a decline in locomotor behavior and bladder physiology outcomes associated with an invasive repair strategy. These results indicate that PNG+aFGF+ChABC treatment of the chronically contused spinal cord can provide a permissive substrate for the regeneration of certain neuronal populations that retain a growth potential over time, and lead to functional improvements.

Cell Therapy as a New Approach to the Treatment of Posttraumatic Syringomyelia

BACKGROUND

Cell transplantation with autologous bone marrow-derived mesenchymal stromal cells (MSCs) seems to be a therapeutic promise for patients with established spinal cord injury, achieving improvement in their quality of life, but there is no experience with the application of this type of cell therapy in patients suffering posttraumatic syringomyelia.

OBJECTIVE

To study the possible utility of cell therapy with autologous MSCs in posttraumatic syringomyelia.

METHODS

A 40-year-old man with complete paraplegia since 1991 as a consequence of a Th4 vertebral fracture showed a great posttraumatic syringomyelia that extended up to C2 vertebral level, without signs of recent worsening. Autologous MSCs (150 × 10⁶) were injected into the syrinx, without drainage or aspiration.

RESULTS

One year after cell therapy, syrinx was reduced without collapse of cervical spinal cord. During the course of follow-up, clear clinical improvement was observed, mainly in sphincter dysfunction.

CONCLUSIONS

Injection of MSCs in the syrinx of posttraumatic syringomyelia is safe and is associated with clinical and neuroimaging improvement. The possibility of cell therapy as a new approach to posttraumatic syringomyelia, or even for idiopathic syringomyelia, is an open door that requires further study.

Remyelination improvement after neurotrophic factors secreting cells transplantation in rat spinal cord injury

OBJECTIVES

Neurotrophic factors secreting cells (NTS-SCs) may be a superior cell source for cell-based therapy in neurodegenerative diseases. NTS-SCs are able to secrete some neurotrophic Such as nerve growth factor and glia-derived neurotrophic factor. Our primary aim was to assess transplantation of neurotrophic factor secreting cells derived from human adipose-derived stem cells (hADSCs) into the damaged spinal cord rats and determine the potential of these cells in remyelination.

MATERIALS AND METHODS

To this end, 40 adult male Wistar rats were categorized into four groups including; control, lysolecithin (Lysophosphatidylcholines or LPC), vehicle, and NTS-SCs transplan-tation. Local demyelination was induced using LPC injection into the lateral column of spinal cord. Seven days after the lysolecithin lesion, the cells transplantation was performed. The ultrastructure of myelinated fibers was examined with a transmission electron microscope to determine the extent of myelin destruction and remyelinization 4 weeks post cell transplantation. Moreover, the presence of oligodendrocyte in the lesion of spinal cord was assessed by immunohistochemistry procedure.

RESULTS

The results of current study indicated that in NTF-SCs transplantation group, the remyelination process and the mean of myelin sheath thickness as well as axonal diameters were significantly higher than other groups (P<0.001). Furthermore, immunohistochemistry analysis revealed that in NTF-SCs transplantation group more than 10 percent of transplanted cells were positive for specific markers of oligodendrocyte cells.

CONCLUSION

NTF-SCs transplantation represents a valuable option for cell-based therapy in the nervous tissue damages.

Concise Review: Innate and Adaptive Immune Recognition of Allogeneic and Xenogeneic Cell Transplants in the Central Nervous System

Over the last 30 years, numerous allogeneic and xenogeneic cell grafts have been transplanted into the central nervous system (CNS) of mice and men in an attempt to cure neurological diseases. In the early studies, human or porcine embryonic neural cells were grafted in the striatum of animals or patients in an attempt to replace lost neurons. Although the immune-privileged status of the brain as a recipient organ was widely accepted, it rapidly became evident that CNS-grafted allogeneic and xenogeneic cells could be recognized and rejected by the immune system, resulting in poor neural graft survival and limited functional recovery. Since then, the CNS transplantation field has witnessed a sharp rise in the number of studies in which allogeneic and xenogeneic neural or mesenchymal stem cells (NSCs or MSCs, respectively) are transplanted, predominantly aiming at providing trophic stimulation and promoting endogenous repair of the brain. Interestingly, in many recent NSC and MSC-based publications functional improvement was used as the principal measure to evaluate the success of cell transplantation, while the fate of transplanted cells remained largely unreported. In this review, we first attempt to understand why primary neural cell isolates were largely substituted for NSCs and MSCs in cell grafting studies. Next, we review the current knowledge on the immune mechanisms involved in the recognition and rejection of allogeneic and xenogeneic cellular grafts in the CNS. Finally, we propose strategies to reduce graft immunogenicity and to improve graft survival in order to design improved cell-based CNS therapies. Stem Cells Translational Medicine 2017;6:1434-1441.

Repeated subarachnoid administrations of autologous mesenchymal stromal cells supported in autologous plasma improve quality of life in patients suffering incomplete spinal cord injury

BACKGROUND AIMS

Cell therapy with mesenchymal stromal cells (MSCs) offers new hope for patients suffering from spinal cord injury (SCI).

METHODS

Ten patients with established incomplete SCI received four subarachnoid administrations of 30 × 10⁶ autologous bone marrow MSCs, supported in autologous plasma, at months 1, 4, 7 and 10 of the study, and were followed until the month 12. Urodynamic, neurophysiological and neuroimaging studies were performed at months 6 and 12, and compared with basal studies.

RESULTS

Variable improvement was found in the patients of the series. All of them showed some degree of improvement in sensitivity and motor function. Sexual function improved in two of the eight male patients. Neuropathic pain was present in four patients before treatment; it disappeared in two of them and decreased in another. Clear improvement in bladder and bowel control were found in all patients suffering previous dysfunction. Before treatment, seven patients suffered spasms, and two improved. Before cell therapy, nine patients suffered variable degree of spasticity, and 3 of them showed clear decrease at the end of follow-up. At this time, nine patients showed infra-lesional electromyographic recordings suggesting active muscle reinnervation, and eight patients showed improvement in bladder compliance. After three administrations of MSCs, mean values of brain-derived neurotrophic factor, glial-derived neurotrophic factor, ciliary neurotrophic factor, and neurotrophin 3 and 4 showed slight increases compared with basal levels, but without statistically significant difference.

CONCLUSIONS

Administration of repeated doses of MSCs by subarachnoid route is a well-tolerated procedure that is able to achieve progressive and significant improvement in the quality of life of patients suffering incomplete SCI.

An approach to personalized cell therapy in chronic complete paraplegia: The Puerta de Hierro phase I/II clinical trial

BACKGROUND AIMS

Cell transplantation in patients suffering spinal cord injury (SCI) is in its initial stages, but currently there is confusion about the results because of the disparity in the techniques used, the route of administration, and the criteria for selecting patients.

METHODS

We conducted a clinical trial involving 12 patients with complete and chronic paraplegia (average time of chronicity, 13.86 years; SD, 9.36). The characteristics of SCI in magnetic resonance imaging (MRI) were evaluated for a personalized local administration of expanded autologous bone marrow mesenchymal stromal cells (MSCs) supported in autologous plasma, with the number of MSCs ranging from 100 × 10(6) to 230 × 10(6). An additional 30 × 10(6) MSCs were administered 3 months later by lumbar puncture into the subarachnoid space. Outcomes were evaluated at 3, 6, 9 and 12 months after surgery through clinical, urodynamic, neurophysiological and neuroimaging studies.

RESULTS

Cell transplantation is a safe procedure. All patients experienced improvement, primarily in sensitivity and sphincter control. Infralesional motor activity, according to clinical and neurophysiological studies, was obtained by more than 50% of the patients. Decreases in spasms and spasticity, and improved sexual function were also common findings. Clinical improvement seems to be dose-dependent but was not influenced by the chronicity of the SCI.

CONCLUSION

Personalized cell therapy with MSCs is safe and leads to clear improvements in clinical aspects and quality of life for patients with complete and chronically established paraplegia.

Histological Study of Bone Marrow and Umbilical Cord Stromal Cell Transplantation in Regenerating Rat Peripheral Nerve

Objective

Bone marrow and umbilical cord stromal cells are multipotential stem cells that have the ability to produce growth factors that play an important role in survival and generation of axons. The goal of this study was to evaluate the effects of the two different mesenchymal stem cells on peripheral nerve regeneration.

Materials and Methods

In this experimental study, a 10 mm segment of the left sciatic nerve of male Wistar rats (250-300 g) was removed with a silicone tube interposed into this nerve gap. Bone marrow stromal cells (BMSCs) and human umbilical cord stromal cells (HUCSCs) were respectively obtained from rat and human. The cells were sepa- rately cultured and transplanted into the nerve gap. The sciatic nerve regeneration was evaluated by immunohistochemistry, and light and electron microscopy. Moreover, histo- morphology of the gastrocnemius muscle was observed.

Results

The nerve regeneration in the BMSCs and HUCSCs groups that had received the stem cells was significantly more favorable than the control group. In addition, the BM- SCs group was significantly more favorable than the HUCSCs group (P<0.05).

Conclusion

The results of this study suggest that both homograft BMSCs and het- erograft HUCSCs may have the potential to regenerate peripheral nerve injury and transplantation of BMSCs may be more effective than HUCSCs in rat.

Chronic spinal cord injury treated with transplanted autologous bone marrow-derived mesenchymal stem cells tracked by magnetic resonance imaging: a case report

INTRODUCTION

Intrathecal transplantation is a minimally invasive method for the delivery of stem cells, however, whether the cells migrate from the lumbar to the injured cervical spinal cord has not been proved in humans. We describe an attempt to track bone marrow-derived mesenchymal stem cells in a patient with a chronic cervical spinal cord injury.

CASE PRESENTATION

A 33-year-old Thai man who sustained an incomplete spinal cord injury from the atlanto-axial subluxation was enrolled into a pilot study aiming to track bone marrow-derived mesenchymal stem cells, labeled with superparamagnetic iron oxide nanoparticles, from intrathecal transplantation in chronic cervical spinal cord injury. He had been dependent on respiratory support since 2005. There had been no improvement in his neurological function for the past 54 months. Bone marrow-derived mesenchymal stem cells were retrieved from his iliac crest and repopulated to the target number. One half of the total cells were labeled with superparamagnetic iron oxide nanoparticles before transplantation to the intrathecal space between L4 and L5. Magnetic resonance imaging studies were performed immediately after the transplantation and at 48 hours, two weeks, one month and seven months after the transplantation. His magnetic resonance imaging scan performed immediately after the transplantation showed hyposignal intensity of paramagnetic substance tagged stem cells in the subarachnoid space at the lumbar spine area. This phenomenon was observed at the surface around his cervical spinal cord at 48 hours. A focal hyposignal intensity of tagged bone marrow-derived stem cells was detected at his cervical spinal cord with magnetic resonance imaging at 48 hours, which faded after two weeks, and then disappeared after one month. No clinical improvement of the neurological function had occurred at the end of this study. However, at 48 hours after the transplantation, he presented with a fever, headache, myalgia and worsening of his motor function (by one grade of all key muscles by the American Spinal Injury Association impairment scale), which lasted for 48 hours.

CONCLUSION

Intrathecal injection of bone marrow-derived stem cells at the lumbar spine level could deliver the cells to the injured cervical spinal cord. Transient complications should be observed closely in the first 48 hours after transplantation. Further study should be carried out to evaluate the result of the treatment.

Negative neuronal differentiation of human adipose-derived stem cell clones

AIMS

Adipose mesenchymal stem cells are a heterogeneous population. Therefore, the question posed in this study is whether the heterogenic differentiation potential exhibited by the different clones toward mesodermic lineages can be extended to nonmesodermic lineages, such as the neuroectoderm.

MATERIALS & METHODS

Different single cell clones of human adipose mesenchymal stem cells from the same donor were isolated. Neuronal plasticity of the clones was assessed according to the pattern DNA methylation, gene expression and intracellular calcium responses.

RESULTS

Under neurogenic culture conditions, clones presented variable expression of neuronal-specific genes, but still expressed osteogenic markers. No calcium response was exhibited in response to KCl incubation. The DNA methylation profile presented a very similar pattern in neuroectoderm gene promoters.

CONCLUSIONS

Data indicate that there are no significant differences between the undifferentiated and supposedly neuronal-differentiated mesenchymal cells.

The role of brain-derived neurotrophic factor in bone marrow stromal cell-mediated spinal cord repair

The ability of intraspinal bone marrow stromal cell (BMSC) transplants to elicit repair is thought to result from paracrine effects by secreted trophic factors including brain-derived neurotrophic factor (BDNF). Here we used gene therapy to increase or silence BDNF production in BMSCs to investigate the role of BDNF in BMSC-mediated neuroprotection. In a spinal cord organotypic culture, BMSC-conditioned medium significantly enhanced spinal motoneuron survival by 64% compared with culture medium only. Only conditioned medium of BDNF-hypersecreting BMSCs sustained this neuroprotective effect. In a rat model of spinal cord contusion, a BDNF-dependent neuroprotective effect was confirmed; only with a subacute transplant of BDNF-hypersecreting BMSCs were significantly more spared motoneurons found at 4 weeks postinjury compared with vehicle controls. Spared nervous tissue volume was improved by 68% with both control BMSCs and BDNF-hypersecreting BMSCs. In addition, blood vessel density in the contusion with BDNF-hypersecreting BMSCs was 35% higher compared with BMSC controls and sixfold higher compared with vehicle controls. BDNF-silenced BMSCs did not survive the first week of transplantation, and no neuroprotective effect was found at 4 weeks after transplantation. Together, our data broaden our understanding of the role of BDNF in BMSC-mediated neuroprotection and successfully exploit BDNF dependency to enhance anatomical spinal cord repair.

Localized delivery of brain-derived neurotrophic factor-expressing mesenchymal stem cells enhances functional recovery following cervical spinal cord injury

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are important in modulating neuroplasticity and promoting recovery after spinal cord injury. Intrathecal delivery of BDNF enhances functional recovery following unilateral spinal cord hemisection (SH) at C2, a well-established model of incomplete cervical spinal cord injury. We hypothesized that localized delivery of BDNF-expressing mesenchymal stem cells (BDNF-MSCs) would promote functional recovery of rhythmic diaphragm activity after SH. In adult rats, bilateral diaphragm electromyographic (EMG) activity was chronically monitored to determine evidence of complete SH at 3 days post-injury, and recovery of rhythmic ipsilateral diaphragm EMG activity over time post-SH. Wild-type, bone marrow-derived MSCs (WT-MSCs) or BDNF-MSCs (2×10(5) cells) were injected intraspinally at C2 at the time of injury. At 14 days post-SH, green fluorescent protein (GFP) immunoreactivity confirmed MSCs presence in the cervical spinal cord. Functional recovery in SH animals injected with WT-MSCs was not different from untreated SH controls (n=10; overall, 20% at 7 days and 30% at 14 days). In contrast, functional recovery was observed in 29% and 100% of SH animals injected with BDNF-MSCs at 7 days and 14 days post-SH, respectively (n=7). In BDNF-MSCs treated SH animals at 14 days, root-mean-squared EMG amplitude was 63±16% of the pre-SH value compared with 12±9% in the control/WT-MSCs group. We conclude that localized delivery of BDNF-expressing MSCs enhances functional recovery of diaphragm muscle activity following cervical spinal cord injury. MSCs can be used to facilitate localized delivery of trophic factors such as BDNF in order to promote neuroplasticity following spinal cord injury.

Comparison of cellular architecture, axonal growth, and blood vessel formation through cell-loaded polymer scaffolds in the transected rat spinal cord

The use of multichannel polymer scaffolds in a complete spinal cord transection injury serves as a deconstructed model that allows for control of individual variables and direct observation of their effects on regeneration. In this study, scaffolds fabricated from positively charged oligo[poly(ethylene glycol)fumarate] (OPF(+)) hydrogel were implanted into rat spinal cords following T9 complete transection. OPF(+) scaffold channels were loaded with either syngeneic Schwann cells or mesenchymal stem cells derived from enhanced green fluorescent protein transgenic rats (eGFP-MSCs). Control scaffolds contained extracellular matrix only. The capacity of each scaffold type to influence the architecture of regenerated tissue after 4 weeks was examined by detailed immunohistochemistry and stereology. Astrocytosis was observed in a circumferential peripheral channel compartment. A structurally separate channel core contained scattered astrocytes, eGFP-MSCs, blood vessels, and regenerating axons. Cells double-staining with glial fibrillary acid protein (GFAP) and S-100 antibodies populated each scaffold type, demonstrating migration of an immature cell phenotype into the scaffold from the animal. eGFP-MSCs were distributed in close association with blood vessels. Axon regeneration was augmented by Schwann cell implantation, while eGFP-MSCs did not support axon growth. Methods of unbiased stereology provided physiologic estimates of blood vessel volume, length and surface area, mean vessel diameter, and cross-sectional area in each scaffold type. Schwann cell scaffolds had high numbers of small, densely packed vessels within the channels. eGFP-MSC scaffolds contained fewer, larger vessels. There was a positive linear correlation between axon counts and vessel length density, surface density, and volume fraction. Increased axon number also correlated with decreasing vessel diameter, implicating the importance of blood flow rate. Radial diffusion distances in vessels significantly correlated to axon number as a hyperbolic function, showing a need to engineer high numbers of small vessels in parallel to improving axonal densities. In conclusion, Schwann cells and eGFP-MSCs influenced the regenerating microenvironment with lasting effect on axonal and blood vessel growth. OPF(+) scaffolds in a complete transection model allowed for a detailed comparative, histologic analysis of the cellular architecture in response to each cell type and provided insight into physiologic characteristics that may support axon regeneration.

Cell-based therapy for the deficient urinary sphincter

When sterile culture techniques of mammalian cells first became state of the art, there was tremendous anticipation that such cells could be eventually applied for therapeutic purposes. The discovery of adult human stem or progenitor cells further motivated scientists to pursue research in cell-based therapies. Although evidence from animal studies suggests that application of cells yields measurable benefits, in urology and many other disciplines, progenitor-cell-based therapies are not yet routinely clinically available. Stress urinary incontinence (SUI) is a condition affecting a large number of patients. The etiology of SUI includes, but is not limited to, degeneration of the urinary sphincter muscle tissue and loss of innervation, as well as anatomical and biomechanical causes. Therefore, different regimens were developed to treat SUI. However, at present, a curative functional treatment is not at hand. A progenitor-cell-based therapy that can tackle the etiology of incontinence, rather than the consequences, is a promising strategy. Therefore, several research teams have intensified their efforts to develop such a therapy for incontinence. Here, we introduce candidate stem and progenitor cells suitable for SUI treatment, show how the functional homogeneity and state of maturity of differentiated cells crucial for proper tissue integration can be assessed electrophysiologically prior to their clinical application, and discuss the trophic potential of adult mesenchymal stromal (or stem) cells in regeneration of neuronal function.

Stem cell transplantation in neurological diseases: improving effectiveness in animal models

Neurological diseases afflict a growing proportion of the human population. There are two reasons for this: first, the average age of the population (especially in the industrialized world) is increasing, and second, the diagnostic tools to detect these pathologies are now more sophisticated and can be used on a higher percentage of the population. In many cases, neurological disease has a pharmacological treatment which, as in the case of Alzheimer's disease, Parkinson's disease, Epilepsy, and Multiple Sclerosis can reduce the symptoms and slow down the course of the disease but cannot reverse its effects or heal the patient. In the last two decades the transplantation approach, by means of stem cells of different origin, has been suggested for the treatment of neurological diseases. The choice of slightly different animal models and the differences in methods of stem cell preparation make it difficult to compare the results of transplantation experiments. Moreover, the translation of these results into clinical trials with human subjects is difficult and has so far met with little success. This review seeks to discuss the reasons for these difficulties by considering the differences between human and animal cells (including isolation, handling and transplantation) and between the human disease model and the animal disease model.

The isolation and cultivation of bone marrow stem cells and evaluation of differences for neural-like cells differentiation under the induction with neurotrophic factors

The bone marrow represents the most common source from which to isolate mesenchymal stem cells (MSCs). They can be obtained directly from patients and successfully induced to form various differentiated cell types. In addition, cell-based transplantation therapies have been proven to be promising strategies for curing disease of the nerve system. Therefore, it was particularly important to establish an easy and feasible method for the isolation, purification, and differentiation of bone marrow stromal cells (BMSCs). The aim of this study was to isolate and characterize putative bone marrow derived MSCs from Sprague-Dawley (SD) rats. Furthermore, differentiation effects were compared between the GDNF-induction group and the BDNF-induction group. Of these, BMSCs were isolated from the SD rats in a traditional manner, and identified based on plastic adherence, morphology, and surface phenotype assays. After induction with GDNF and BDNF, viability of BMSCs was detected by MTT assay and neuronal differentiation of BMSCs was confirmed by using immunofluorescence and Western blotting. Besides, the number of BMSCs that obviously exhibited neuronal morphology was counted and the results were compared between the GDNF-induction group and BDNF-induction groups. Our results indicate that direct adherence was a simple and convenient method for isolation and cultivation of BMSCs. Furthermore, BMSCs can be induced in vitro to differentiate into neuronal cells by using GDNF, which could achieve a more persistent and stable inducing effect than when using BDNF.

Clinical neurofunctional rehabilitation of a cat with spinal cord injury after hemilaminectomy and autologous stem cell transplantation

Stem cell-based therapy has been investigated in a number of degenerative and traumatic diseases, including spinal cord injury. In the present study, we investigated the use of autologous mesenchymal stem cells in the functional rehabilitation of a domestic cat presenting a compressive L1-L5 fracture. Bone marrow cells collected by puncture of the iliac crest were cultured to obtain mesenchymal stem cells three weeks before surgery. Hemilaminectomy was performed, followed by injection of the mesenchymal stem cells in the injured area. Clinical evaluation of the animal prior to surgery showed absence of pain, muscular tonus, and panniculi reflexes. Seven days after surgery and cell transplantation the examination revealed a progressive recovery of the panniculus reflexes and of the responses to superficial and deep pain stimuli despite the low proprioceptive and hyperreflexic ataxic hind limbs. Physiotherapy protocols were applied for clinical rehabilitation after surgery. The cat's first steps, three-minute weight-bearing, and intestine and urinary bladder partial reestablishment were observed 75 days post-surgery. Our results indicate the therapeutic potential of mesenchymal stem cells in chronic spinal cord injuries.

From basics to clinical: a comprehensive review on spinal cord injury

Spinal cord injury (SCI) is a devastating neurological disorder that affects thousands of individuals each year. Over the past decades an enormous progress has been made in our understanding of the molecular and cellular events generated by SCI, providing insights into crucial mechanisms that contribute to tissue damage and regenerative failure of injured neurons. Current treatment options for SCI include the use of high dose methylprednisolone, surgical interventions to stabilize and decompress the spinal cord, and rehabilitative care. Nonetheless, SCI is still a harmful condition for which there is yet no cure. Cellular, molecular, rehabilitative training and combinatorial therapies have shown promising results in animal models. Nevertheless, work remains to be done to ascertain whether any of these therapies can safely improve patient's condition after human SCI. This review provides an extensive overview of SCI research, as well as its clinical component. It starts covering areas from physiology and anatomy of the spinal cord, neuropathology of the SCI, current clinical options, neuronal plasticity after SCI, animal models and techniques to assess recovery, focusing the subsequent discussion on a variety of promising neuroprotective, cell-based and combinatorial therapeutic approaches that have recently moved, or are close, to clinical testing.

Mesenchymal stem cells secretome: a new paradigm for central nervous system regeneration?

The low regeneration potential of the central nervous system (CNS) represents a challenge for the development of new therapeutic strategies. Mesenchymal stem cells (MSCs) have been proposed as a possible therapeutic tool for CNS disorders. In addition to their differentiation potential, it is well accepted nowadays that their beneficial actions can also be mediated by their secretome. Indeed, it was already demonstrated, both in vitro and in vivo, that MSCs are able to secrete a broad range of neuroregulatory factors that promote an increase in neurogenesis, inhibition of apoptosis and glial scar formation, immunomodulation, angiogenesis, neuronal and glial cell survival, as well as relevant neuroprotective actions on different pathophysiological contexts. Considering their protective action in lesioned sites, MSCs' secretome might also improve the integration of local progenitor cells in neuroregeneration processes, opening a door for their future use as therapeutical strategies in human clinical trials. Thus, in this review we analyze the current understanding of MSCs secretome as a new paradigm for the treatment of CNS neurodegenerative diseases.

Cell therapy with bone marrow stromal cells after intracerebral hemorrhage: impact of platelet-rich plasma scaffolds

BACKGROUND AIMS

Cell therapy using bone marrow stromal cells (BMSCs) has been considered a promising strategy for neurologic sequelae after intracerebral hemorrhage (ICH). However, after intracerebral administration of BMSCs, most of the cells die, partly because of the absence of extracellular matrix. Intracerebral transplantation of BMSCs, supported in a platelet-rich plasma (PRP) scaffold, optimizes this type of cell therapy.

METHODS

ICH was induced by stereotactic injection of 0.5 IU of collagenase type IV in the striatum of adult Wistar rats (n = 40). Two months later, the rats were subjected to intracerebral administration of 5 × 10(6) allogeneic BMSCs embedded in a PRP scaffold (n = 10), 5 × 10(6) allogeneic BMSCs in saline (n = 10), PRP-derived scaffold only (n = 10) or saline only (n = 10). Functional improvements in each group over the next 6 months were assessed using Rotarod and Video-Tracking-Box tests. Endogenous neurogenesis and survival of transplanted BMSCs were examined at the end of follow-up.

RESULTS

Our study demonstrated neurologic improvement after BMSC transplantation and significantly better functional improvement for the group of animals that received BMSCs in the PRP-derived scaffold compared with the group that received BMSCs in saline. Histologic results showed that better functional outcome was associated with strong activation of endogenous neurogenesis. After intracerebral administration of BMSCs, donor cells were integrated in the injured tissue and showed phenotypic expression of glial fibrillary acidic protein and neuronal nucleus.

CONCLUSIONS

PRP-derived scaffolds increase the viability and biologic activity of BMSCs and optimize functional recovery when this type of cell therapy is applied after ICH.

A comparison of the behavioral and anatomical outcomes in sub-acute and chronic spinal cord injury models following treatment with human mesenchymal precursor cell transplantation and recombinant decorin

This study assessed the potential of highly purified (Stro-1(+)) human mesenchymal precursor cells (hMPCs) in combination with the anti-scarring protein decorin to repair the injured spinal cord (SC). Donor hMPCs isolated from spinal cord injury (SCI) patients were transplanted into athymic rats as a suspension graft, alone or after previous treatment with, core (decorin(core)) and proteoglycan (decorin(pro)) isoforms of purified human recombinant decorin. Decorin was delivered via mini-osmotic pumps for 14 days following sub-acute (7 day) or chronic (1 month) SCI. hMPCs were delivered to the spinal cord at 3 weeks or 6 weeks after the initial injury at T9 level. Behavioral and anatomical analysis in this study showed statistically significant improvement in functional recovery, tissue sparing and cyst volume reduction following hMPC therapy. The combination of decorin infusion followed by hMPC therapy did not improve these measured outcomes over the use of cell therapy alone, in either sub-acute or chronic SCI regimes. However, decorin infusion did improve tissue sparing, reduce spinal tissue cavitation and increase transplanted cell survivability as compared to controls. Immunohistochemical analysis of spinal cord sections revealed differences in glial, neuronal and extracellular matrix molecule expression within each experimental group. hMPC transplanted spinal cords showed the increased presence of serotonergic (5-HT) and sensory (CGRP) axonal growth within and surrounding transplanted hMPCs for up to 2 months; however, no evidence of hMPC transdifferentiation into neuronal or glial phenotypes. The number of hMPCs was dramatically reduced overall, and no transplanted cells were detected at 8 weeks post-injection using lentiviral GFP labeling and human nuclear antigen antibody labeling. The presence of recombinant decorin in the cell transplantation regimes delayed in part the loss of donor cells, with small numbers remaining at 2 months after transplantation. In vitro co-culture experiments with embryonic dorsal root ganglion explants revealed the growth promoting properties of hMPCs. Decorin did not increase axonal outgrowth from that achieved by hMPCs. We provide evidence for the first time that (Stro-1(+)) hMPCs provide: i) an advantageous source of allografts for stem cell transplantation for sub-acute and chronic spinal cord therapy, and (ii) a positive host microenvironment that promotes tissue sparing/repair that subsequently improves behavioral outcomes after SCI. This was not measurably improved by recombinant decorin treatment, but does provide important information for the future development and potential use of decorin in contusive SCI therapy.

Minocycline treatment and bone marrow mononuclear cell transplantation after endothelin-1 induced striatal ischemia

We explored whether the modulation of microglia activation with minocycline is beneficial to the therapeutic actions of bone marrow mononuclear cells (BMMCs) transplanted after experimental stroke. Male Wistar adult rats were divided in four experimental groups: ischemic control saline treated (G1, N = 6), ischemic minocycline treated (G2, N = 5), ischemic BMMC treated (G3, N = 5), and ischemic minocycline/BMMC treated (G4, N = 6). There was a significant reduction in the number of ED1+ cells in G3 animals (51.31 ± 2.41, P < 0.05), but this effect was more prominent following concomitant treatment with minocycline (G4 = 29.78 ± 1.56). There was conspicuous neuronal preservation in the brains of G4 animals (87.97 ± 4.27) compared with control group (G1 = 47.61 ± 2.25, P < 0.05). The behavioral tests showed better functional recovery in animals of G2, G3, and G4, compared with G1 and baseline (P < 0.05). The results suggest that a proper modulation of microglia activity may contribute to a more permissive ischemic environment contributing to increased neuroprotection and functional recovery following striatal ischemia.

Exposure to ELF- magnetic field promotes restoration of sensori-motor functions in adult rats with hemisection of thoracic spinal cord

Clinically effective modalities of treatment for spinal cord injury (SCI) still remain unsatisfactory and are largely invasive in nature. There are reports of accelerated regeneration in injured peripheral nerves by extremely low-frequency pulsed electromagnetic field (ELF-EMF) in the rat. In the present study, the effect of (50 Hz), low-intensity (17.96 μT) magnetic field (MF) exposure of rats after-hemisection of T13 spinal cord (hSCI) was investigated on sensori-motor and locomotor functions. Rats were divided into hSCI (sham-exposed) and hSCI+MF (MF: 2 h/d X 6 weeks) groups. Besides their general conditions, locomotor function by Basso, Beattie, and Brenahan (BBB) score; motor responses to noxious stimuli by threshold of tail flick (TTF), simple vocalization (TSV), tail flick latency (TFL), and neuronal excitability by H-reflex were noted. It is found that, in the hSCI+MF group, a statistically significant improvement over the hSCI control group was noted in BBB score from post-SCI wk2 and TFL and TTF by post-hSCI wk1 and wk3, respectively. Correspondingly, TSV gradually restored by post-hSCI wk5.The threshold of H-reflex was reduced on ipsilateral side vs. contralateral side in hSCI and hSCI+MF group. A complete bladder control was dramatically restored on post-hSCI day4 (vs. day7 of hSCI group) and the survival rate was 100% in the hSCI+MF group (vs. 90% of hSCI group). The results of our study suggest that extremely low-frequency (50 Hz), low-intensity (17.96 μT) MF exposure for 2 h/d x 6wks promotes recovery of sensori-motor behavior including locomotion and bladder control both in terms of temporal pattern and magnitude in hemisection injury of (T13) spinal cord rats.

Mesenchymal autologous stem cells

The use of cell-based therapies for spinal cord injuries has recently gained prominence as a potential therapy or component of a combination strategy. Experimental and clinical studies have been performed using mesenchymal stem cell therapy to treat spinal cord injuries with encouraging results. However, there have been reports on the adverse effects of these stem cell-based therapies, especially in the context of tumor modulation. This article surveys the literature relevant to the potential of mesenchymal autologous stem cells for spinal cord injuries and their clinical implications.

Effects of human mesenchymal stem cell transplantation combined with polymer on functional recovery following spinal cord hemisection in rats

The spontaneous axon regeneration of damaged neurons is limited after spinal cord injury (SCI). Recently, mesenchymal stem cell (MSC) transplantation was proposed as a potential approach for enhancing nerve regeneration that avoids the ethical issues associated with embryonic stem cell transplantation. As SCI is a complex pathological entity, the treatment of SCI requires a multipronged approach. The purpose of the present study was to investigate the functional recovery and therapeutic potential of human MSCs (hMSCs) and polymer in a spinal cord hemisection injury model. Rats were subjected to hemisection injuries and then divided into three groups. Two groups of rats underwent partial thoracic hemisection injury followed by implantation of either polymer only or polymer with hMSCs. Another hemisection-only group was used as a control. Behavioral, electrophysiological and immunohistochemical studies were performed on all rats. The functional recovery was significantly improved in the polymer with hMSC-transplanted group as compared with control at five weeks after transplantation. The results of electrophysiologic study demonstrated that the latency of somatosensory-evoked potentials (SSEPs) in the polymer with hMSC-transplanted group was significantly shorter than in the hemisection-only control group. In the results of immunohistochemical study, β-gal-positive cells were observed in the injured and adjacent sites after hMSC transplantation. Surviving hMSCs differentiated into various cell types such as neurons, astrocytes and oligodendrocytes. These data suggest that hMSC transplantation with polymer may play an important role in functional recovery and axonal regeneration after SCI, and may be a potential therapeutic strategy for SCI.

Long-term results of spinal cord injury therapy using mesenchymal stem cells derived from bone marrow in humans

BACKGROUND

Although the transplantation of mesenchymal stem cells (MSCs) after spinal cord injury (SCI) has shown promising results in animals, less is known about the effects of autologous MSCs in human SCI.

OBJECTIVE

To describe the long-term results of 10 patients who underwent intramedullary direct MSCs transplantation into injured spinal cords.

METHODS

Autologous MSCs were harvested from the iliac bone of each patient and expanded by culturing for 4 weeks. MSCs (8 × 10) were directly injected into the spinal cord, and 4 × 10 cells were injected into the intradural space of 10 patients with American Spinal Injury Association class A or B injury caused by traumatic cervical SCI. After 4 and 8 weeks, an additional 5 × 10 MSCs were injected into each patient through lumbar tapping. Outcome assessments included changes in the motor power grade of the extremities, magnetic resonance imaging, and electrophysiological recordings.

RESULTS

Although 6 of the 10 patients showed motor power improvement of the upper extremities at 6-month follow-up, 3 showed gradual improvement in activities of daily living, and changes on magnetic resonance imaging such as decreases in cavity size and the appearance of fiber-like low signal intensity streaks. They also showed electrophysiological improvement. All 10 patients did not experience any permanent complication associated with MSC transplantation.

CONCLUSION

Three of the 10 patients with SCI who were directly injected with autologous MSCs showed improvement in the motor power of the upper extremities and in activities of daily living, as well as significant magnetic resonance imaging and electrophysiological changes during long-term follow-up.