Autologous bone marrow transplantation in patients with subacute and chronic spinal cord injury

Feasibility investigation of allogeneic endometrial regenerative cells

Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like stem cells having pluripotent differentiation activity and ability to induce neoangiogenesis. In vitro and animal studies suggest ERC are immune privileged and in certain situations actively suppress ongoing immune responses. In this paper we describe the production of clinical grade ERC and initial safety experiences in 4 patients with multiple sclerosis treated intravenously and intrathecally. The case with the longest follow up, of more than one year, revealed no immunological reactions or treatment associated adverse effects. These preliminary data suggest feasibility of clinical ERC administration and support further studies with this novel stem cell type.

Grafting of human bone marrow stromal cells into spinal cord injury: a comparison of delivery methods

STUDY DESIGN

Three groups of 6 rats received subtotal cervical spinal cord hemisections followed with marrow stromal cell (MSC) transplants by lumbar puncture (LP), intravenous delivery (IV), or direct injection into the injury (control). Animals survived for 4 or 21 days.

OBJECTIVE

Cell therapy is a promising strategy for the treatment of spinal cord injury (SCI). The mode of cell delivery is crucial for the translation to the clinic. Injections directly into the parenchyma may further damage already compromised tissue; therefore, less invasive methods like LP or IV delivery are preferable.

SUMMARY OF BACKGROUND DATA

Human MSC are multipotent mesenchymal adult stem cells that have a potential for autologous transplantation, obviating the need for immune suppression. Although previous studies have established that MSC can be delivered to the injured spinal cord by both LP and IV, the efficacy of cell delivery has not been directly compared with respect to efficacy of delivery and effects on the host.

METHODS

Purified MSC from a human donor were transplanted into the CSF at the lumbar region (LP), into the femoral vein (IV), or directly into the injury (control). After sacrifice, spinal cord sections were analyzed for MSC graft size, tissue sparing, host immune response, and glial scar formation, using specific antibodies and Nissl-myelin staining.

RESULTS

LP delivery of MSC to the injured spinal cord is superior to IV delivery. Cell engraftment and tissue sparing were significantly better after LP delivery, and host immune response after LP delivery was reduced compared with IV delivery.

CONCLUSION

LP is an ideal minimally invasive technique to deliver cellular transplants to the injured spinal cord. It is superior to IV delivery and, together with the potential for autologous transplantation, lends itself for clinical application.

New perspectives for the treatment options in spinal cord injury

Spinal cord injury (SCI) is a serious clinical disorder that leads to lifetime disability for which no suitable therapeutic agents are available so far. Further research is needed to understand the basic mechanisms of spinal cord pathology that results in permanent disability and poses a heavy burden on our society. In the past, a lot of effort was placed on improving functional outcome with the help of various therapeutic agents, however less attention has been paid on the development and propagation of spinal cord pathology over time. Thus, it is still unclear whether improvement of functional outcome is related to spinal cord pathology or vice versa. Few drugs are able to influence functional outcome without having any improvement on cord pathology. Some drugs, however, can lessen cord pathology but fail to influence the functional outcome. The goal of future treatment options for SCI is therefore to find suitable new drugs or a combination of existing drugs and to use various cellular transplants, neurotrophic factors, myelin-inhibiting factors, tissue engineering and nano-drug delivery to improve both the functional and the pathological outcome in the inured patient. This review deals with the key aspects of the latest treatments for SCI and suggests some possible future therapeutic measures to enhance healthcare in clinical situations.

Functional recovery of chronic paraplegic pigs after autologous transplantation of bone marrow stromal cells

BACKGROUND

Bone marrow stromal cells (BMSC) transplantation offers promise in the treatment of chronic paraplegia in rodents. Here, we report the effect of this cell therapy in adult pigs suffering chronic paraplegia.

METHODS

Three months after spinal cord injury, autologous BMSC in autologous plasma was injected into lesion zone and adjacent subarachnoid space in seven paraplegic pigs. On the contrary, three paraplegic pigs only received autologous plasma. Functional outcome was measured weekly until the end of the follow-up, 3 months later.

RESULTS

Our present study showed progressive functional recovery in transplanted pigs. At this time, intramedullary posttraumatic cavities were filled by a neoformed tissue containing several axons, together with BMSC that expressed neuronal or glial markers. Furthermore, in the treated animals, electrophysiological studies showed recovery of the previously abolished somatosensory-evoked potentials.

CONCLUSIONS

These findings confirm previous observations in rodents and support the possible utility of BMSC transplantation in humans suffering chronic paraplegia.

Updates on stem cells and their applications in regenerative medicine

Stem cells have the capacity for self-renewal and capability of differentiation to various cell lineages. Thus, they represent an important building block for regenerative medicine and tissue engineering. These cells can be broadly classified into embryonic stem cells (ESCs) and non-embryonic or adult stem cells. ESCs have great potential but their use is still limited by several ethical and scientific considerations. The use of bone marrow-, umbilical cord-, adipose tissue-, skin- and amniotic fluid-derived mesenchymal stem cells might be an adequate alternative for translational practice. In particular, bone marrow-derived stem cells have been used successfully in the clinic for bone, cartilage, spinal cord, cardiac and bladder regeneration. Several preclinical experimental studies are under way for the application of stem cells in other conditions where current treatment options are inadequate. Stem cells can be used to improve healthcare by either augmenting the body's own regenerative potential or developing new therapies. This review is not meant to be exhaustive but gives a brief outlook on the past, present and the future of stem cell-based therapies in clinical practice.

Transplantation of human bone marrow-derived stromal cells into the contused spinal cord of nude rats

OBJECT

Human bone marrow stromal cells (hMSCs) constitute a potential source of pluripotent stem cells. In the present study, hMSCs were transplanted into an area of spinal cord contusion in nude rats to determine their survival, differentiation, potential for neuroprotection, and influence on axonal growth and functional recovery.

METHODS

Twenty-nine animals received 6 x 10(5) hMSCs in 6 microl medium 1 week after a contusion, while 14 control animals received an injection of 6 microl medium alone. Basso-Beattie-Bresnahan (BBB) tests were performed weekly. The spinal cords were collected at 6 weeks posttransplantation for histological analysis and assessment of tissue injury.

RESULTS

Immunostaining with anti-human mitochondria antibody and pretransplantation labeling with green fluorescent protein demonstrated that the grafted hMSCs survived and were capable of achieving a flattened appearance in the grafted area; however, none of the transplanted cells stained positively for human-specific neuronal, anti-neurofilament H or glial fibrillary acidic protein within the sites of engraftment. While neuronal or astrocytic differentiation was not seen, cells lining blood vessels in the vicinity of the transplant stained positively for anti-human endothelium CD105 antibody. Staining for anti-neurofilament H antibody demonstrated abundant axonlike structures around the transplanted area in the hMSC group. Tissue sparing analysis showed that animals with grafted hMSCs had a smaller area of contusion cyst compared with controls, but there was no significant difference between the two groups in BBB scores.

CONCLUSIONS

The grafted hMSCs survived for > or = 6 weeks posttransplantation, although they did not differentiate into neural or glial cells. Cells with human endothelial characteristics were observed. Spinal cord-injured rats grafted with hMSCs had smaller contusion cavities, which did not have a significant influence on functional recovery.

Acute and delayed implantation of positively charged 2-hydroxyethyl methacrylate scaffolds in spinal cord injury in the rat

OBJECT

Hydrogels are nontoxic, chemically inert synthetic polymers with a high water content and large surface area that provide mechanical support for cells and axons when implanted into spinal cord tissue.

METHODS

Macroporous hydrogels based on 2-hydroxyethyl methacrylate (HEMA) were prepared by radical copolymerization of monomers in the presence of fractionated NaCl particles. Male Wistar rats underwent complete spinal cord transection at the T-9 level. To bridge the lesion, positively charged HEMA hydrogels were implanted either immediately or 1 week after spinal cord transection; control animals were left untreated. Histological evaluation was performed 3 months after spinal cord transection to measure the volume of the pseudocyst cavities and the ingrowth of tissue elements into the hydrogels.

RESULTS

The hydrogel implants adhered well to the spinal cord tissue. Histological evaluation showed ingrowth of connective tissue elements, blood vessels, neurofilaments, and Schwann cells into the hydrogels. Morphometric analysis of lesions showed a statistically significant reduction in pseudocyst volume in the treated animals compared with controls and in the delayed treatment group compared with the immediate treatment group (p < 0.001 and p < 0.05, respectively).

CONCLUSIONS

Positively charged HEMA hydrogels can bridge a posttraumatic spinal cord cavity and provide a scaffold for the ingrowth of regenerating axons. The results indicate that delayed implantation can be more effective than immediate reconstructive surgery.

Umbilical cord blood transfusions for prevention of progressive brain injury and induction of neural recovery: an immunological perspective

One of the most promising treatments for neurodegenerative diseases appears to be human umbilical cord blood cell transplantation. A variety of studies demonstrate some benefit of this method of treatment in a number of different animal models and case studies. However, before the methodologies and results of these animal studies and case studies can be translated into successful widespread treatments, aspects relating to the immunological properties of the transplanted cells must be considered. In this perspective, we discuss the benefit of the cellular immaturity of these cells with respect to the immune response, and compare cord blood transplantation to blood transfusions, as well as discussing what future studies should entail.

Low Concentration of Isoflurane Promotes the Development of Neurogenic Pulmonary Edema in Spinal Cord Injured Rats

Anesthetics can either promote or inhibit the development of neurogenic pulmonary edema (NPE) after central nervous system (CNS) injury. The influence of isoflurane was examined in male Wistar rats using 1.5%, 2%, 2.5%, 3%, 4%, or 5% isoflurane in air. Epidural balloon compression of the thoracic spinal cord was performed. The development of NPE was examined in vivo and on histologic sections of lung tissue. Animals anesthetized with 1.5% or 3% isoflurane were behaviorally monitored using the BBB and plantar tests for 7 weeks post-injury. The spinal cord was examined using MRI and morphometry of the spared white and gray matter. All animals from the 1.5% and 2% groups developed NPE. Almost 42% of the animals in the 1.5% group died of severe pulmonary hemorrhage and suffocation; x-rays, the pulmonary index, and the histological picture revealed a massive NPE. More than 71% of the animals from the 2.5% and 3% groups did not develop any signs of NPE. Blood pressure after spinal cord compression rose more in the 1.5% group than in the 3% one. In the 1.5% group, the sympathetic ganglionic blockade prevented the neurogenic pulmonary edema development. Animals from the 3% group recovered behaviorally more rapidly than did the animals from the 1.5% group; morphometry and MRI of the lesions showed no differences. Thus, low levels of isoflurane anesthesia promote NPE in rats with a compressed spinal cord and significantly complicates their recovery. The optimal concentration of anesthesia for performing a spinal cord compression lesion is 2.5-3% isoflurane in air.

Potential roles of bone marrow stem cells in stroke therapy

There is a need for improved therapies, in terms of utility and effectiveness, for stroke patients; however, over the years, numerous clinical trials of potential drugs have failed to demonstrate positive results. The emerging field of stem cell research has raised several hopes of a therapy for neurological diseases, including stroke. This review discusses the recent clinical trials and pilot studies using stem cells in stroke patients and highlights key issues that must be addressed to improve the chances of successfully developing a new strategy for stroke patients using adult stem cells.

Complete spinal cord injury treatment using autologous bone marrow cell transplantation and bone marrow stimulation with granulocyte macrophage-colony stimulating factor: Phase I/II clinical trial

To assess the safety and therapeutic efficacy of autologous human bone marrow cell (BMC) transplantation and the administration of granulocyte macrophage-colony stimulating factor (GM-CSF), a phase I/II open-label and nonrandomized study was conducted on 35 complete spinal cord injury patients. The BMCs were transplanted by injection into the surrounding area of the spinal cord injury site within 14 injury days (n = 17), between 14 days and 8 weeks (n = 6), and at more than 8 weeks (n = 12) after injury. In the control group, all patients (n = 13) were treated only with conventional decompression and fusion surgery without BMC transplantation. The patients underwent preoperative and follow-up neurological assessment using the American Spinal Injury Association Impairment Scale (AIS), electrophysiological monitoring, and magnetic resonance imaging (MRI). The mean follow-up period was 10.4 months after injury. At 4 months, the MRI analysis showed the enlargement of spinal cords and the small enhancement of the cell implantation sites, which were not any adverse lesions such as malignant transformation, hemorrhage, new cysts, or infections. Furthermore, the BMC transplantation and GM-CSF administration were not associated with any serious adverse clinical events increasing morbidities. The AIS grade increased in 30.4% of the acute and subacute treated patients (AIS A to B or C), whereas no significant improvement was observed in the chronic treatment group. Increasing neuropathic pain during the treatment and tumor formation at the site of transplantation are still remaining to be investigated. Long-term and large scale multicenter clinical study is required to determine its precise therapeutic effect. Disclosure of potential conflicts of interest is found at the end of this article.

Migration, fate and in vivo imaging of adult stem cells in the CNS

Adult stem cells have been intensively studied for their potential use in cell therapies for neurodegenerative diseases, ischemia and traumatic injuries. One of the most promising cell sources for autologous cell transplantation is bone marrow, containing a heterogenous cell population that can be roughly divided into hematopoietic stem and progenitor cells and mesenchymal stem cells (MSCs). MSCs are multipotent progenitor cells that, in the case of severe tissue ischemia or damage, can be attracted to the lesion site, where they can secrete bioactive molecules, either naturally or through genetic engineering. They can also serve as vehicles for delivering therapeutic agents. Mobilized from the marrow, sorted or expanded in culture, MSCs can be delivered to the damaged site by direct or systemic application. In addition, MSCs can be labeled with superparamagnetic nanoparticles that allow in vivo cell imaging. Magnetic resonance imaging (MRI) is thus a suitable method for in vivo cell tracking of transplanted cells in the host organism. This review will focus on cell labeling for MRI and the use of MSCs in experimental and clinical studies for the treatment of brain and spinal cord injuries.