BAPTA, a calcium chelator, neuroprotects injured neurons in vitro and promotes motor recovery after spinal cord transection in vivo.

AIM: Despite animal evidence of a role of calcium in the pathogenesis of spinal cord injury, several studies conducted in the past found calcium blockade ineffective. However, those studies involved oral or parenteral administration of Ca++ antagonists. We hypothesized that Ca++ blockade might be effective with local/immediate application (LIA) at the time of neural injury. METHODS: In this study, we assessed the effects of LIA of BAPTA (1,2-bis (o-aminophenoxy) ethane-N, N, N', N'-tetraacetic acid), a cell-permeable highly selective Ca++ chelator, after spinal cord transection (SCT) in mice over 4 weeks. Effects of BAPTA were assessed behaviorally and with immunohistochemistry. Concurrently, BAPTA was submitted for the first time to multimodality assessment in an in vitro model of neural damage as a possible spinal neuroprotectant. RESULTS: We demonstrate that BAPTA alleviates neuronal apoptosis caused by physical damage by inhibition of neuronal apoptosis and reactive oxygen species (ROS) generation. This translates to enhanced preservation of electrophysiological function and superior behavioral recovery. CONCLUSION: This study shows for the first time that local/immediate application of Ca++ chelator BAPTA is strongly neuroprotective after severe spinal cord injury.

Reconstruction of the spinal cord of spinal transected dogs with polyethylene glycol.

BACKGROUND: Our study shows that a membrane sealant/fiber fusogen polyethylene glycol (PEG) applied immediately on a sharp section of the spinal cord can mend the cord and lead to exceptional levels of motor recovery, with some animals almost normal. MATERIALS AND METHODS: Before deploying such technology in man, long-term data in large mammals that exclude delayed complications (e.g., central pain), confirm the stability of motor recovery, and provide histological evidence of fiber regrowth are necessary. Here, we provide such evidence in dogs followed up over 6 months and in 2 cases up to 1 year along with imaging and histologic data. RESULTS: We show that dogs whose dorsal cord has been fully transected recover locomotion after immediate treatment with a fusogen (PEG). No pain syndrome ensued over the long term. Diffusion tensor imaging magnetic resonance and histological, including immunohistochemical, data confirmed the re-establishment of anatomical continuity along with interfacial axonal sprouting. CONCLUSIONS: This study proves that a form of irreversible spinal cord injury (SCI) can effectively be treated and points out a way to treat SCI patients.

Bridging the gap: Spinal cord fusion as a treatment of chronic spinal cord injury.

Despite decades of animal experimentation, human translation with cell grafts, conduits, and other strategies has failed to cure patients with chronic spinal cord injury (SCI). Recent data show that motor deficits due to spinal cord transection in animal models can be reversed by local application of fusogens, such as Polyethylene glycol (PEG). Results proved superior at short term over all other treatments deployed in animal studies, opening the way to human trials. In particular, removal of the injured spinal cord segment followed by PEG fusion of the two ends along with vertebral osteotomy to shorten the spine holds the promise for a cure in many cases.

Effect of Graphene Nanoribbons (TexasPEG) on locomotor function recovery in a rat model of lumbar spinal cord transection.

A sharply transected spinal cord has been shown to be fused under the accelerating influence of membrane fusogens such as polyethylene glycol (PEG) (GEMINI protocol). Previous work provided evidence that this is in fact possible. Other fusogens might improve current results. In this study, we aimed to assess the effects of PEGylated graphene nanoribons (PEG-GNR, and called "TexasPEG" when prepared as 1wt% dispersion in PEG600) versus placebo (saline) on locomotor function recovery and cellular level in a rat model of spinal cord transection at lumbar segment 1 (L1) level. In vivo and in vitro experiments (n = 10 per experiment) were designed. In the in vivo experiment, all rats were submitted to full spinal cord transection at L1 level. Five weeks later, behavioral assessment was performed using the Basso Beattie Bresnahan (BBB) locomotor rating scale. Immunohistochemical staining with neuron marker neurofilament 200 (NF200) antibody and astrocytic scar marker glial fibrillary acidic protein (GFAP) was also performed in the injured spinal cord. In the in vitro experiment, the effects of TexasPEG application for 72 hours on the neurite outgrowth of SH-SY5Y cells were observed under the inverted microscope. Results of both in vivo and in vitro experiments suggest that TexasPEG reduces the formation of glial scars, promotes the regeneration of neurites, and thereby contributes to the recovery of locomotor function of a rat model of spinal cord transfection.

Restoration of motor function after operative reconstruction of the acutely transected spinal cord in the canine model.

BACKGROUND: Cephalosomatic anastomosis or what has been called a "head transplantation" requires full reconnection of the respective transected ends of the spinal cords. The GEMINI spinal cord fusion protocol has been developed for this reason. Here, we report the first randomized, controlled study of the GEMINI protocol in large animals. METHODS: We conducted a randomized, controlled study of a complete transection of the spinal cord at the level of T10 in dogs at Harbin Medical University, Harbin, China. These dogs were followed for up to 8 weeks postoperatively by assessments of recovery of motor function, somato-sensory evoked potentials, and diffusion tensor imaging using magnetic resonance imaging. RESULTS: A total of 12 dogs were subjected to operative exposure of the dorsal aspect of the spinal cord after laminectomy and longitudinal durotomy followed by a very sharp, controlled, full-thickness, complete transection of the spinal cord at T10. The fusogen, polyethylene glycol, was applied topically to the site of the spinal cord transection in 7 of 12 dogs; 0.9% NaCl saline was applied to the site of transection in the remaining 5 control dogs. Dogs were selected randomly to receive polyethylene glycol or saline. All polyethylene glycol-treated dogs reacquired a substantial amount of motor function versus none in controls over these first 2 months as assessed on the 20-point (0-19), canine, Basso-Beattie-Bresnahan rating scale (P<.006). Somatosensory evoked potentials confirmed restoration of electrical conduction cranially across the site of spinal cord transection which improved over time. Diffusion tensor imaging, a magnetic resonance permutation that assesses the integrity of nerve fibers and cells, showed restitution of the transected spinal cord with polyethylene glycol treatment (at-injury level difference: P<.02). CONCLUSION: A sharply and fully transected spinal cord at the level of T10 can be reconstructed with restoration of many aspects of electrical continuity in large animals following the GEMINI spinal cord fusion protocol, with objective evidence of motor recovery and of electrical continuity across the site of transection, opening the way to the first cephalosomatic anastomosis. (Surgery 2017;160:XXX-XXX.).

First cephalosomatic anastomosis in a human model.

BACKGROUND: Cephalosomatic anastomosis (CSA) has never been attempted before in man as the transected spinal cords of the body donor and body recipient could not be "fused" back together. Recent advances made this possible. Here, we report on the surgical steps necessary to reconnect a head to a body at the cervical level. METHODS: Full rehearsal of a CSA on two recently deceased human cadavers was performed at Harbin Medical University, Harbin, China. RESULTS: The surgery took 18 hours to complete within the time frame planned for this surgery. Several advances resulted from this rehearsal, including optimization of the surgical steps, sparing of the main nerves (phrenics, recurrent laryngeal nerves), and assessment of vertebral stabilization. CONCLUSION: Several specialties are involved in a full-scale CSA, including neck surgery, vascular surgery, orthopedic surgery, plastic surgery, gastrointestinal surgery, and neurosurgery, as well as the operating staff. This rehearsal confirmed the surgical feasibility of a human CSA and further validated the surgical plan. Education and coordination of all the operating teams and coordination of the operative staff was achieved in preparation for the live human CSA.

Polyethylene glycol-induced motor recovery after total spinal transection in rats.

AIMS: Despite more than a century of research, spinal paralysis remains untreatable via biological means. A new understanding of spinal cord physiology and the introduction of membrane fusogens have provided new hope that a biological cure may soon become available. However, proof is needed from adequately powered animal studies. METHODS AND RESULTS: Two groups of rats (n=9, study group, n=6 controls) were submitted to complete transection of the dorsal cord at T10. The animals were randomized to receive either saline or polyethylene glycol (PEG) in situ. After 4 weeks, the treated group had recovered ambulation vs none in the control group (BBB scores; P=.0145). One control died. All animals were studied with somatosensory-evoked potentials (SSEP) and diffusion tensor imaging (DTI). SSEP recovered postoperatively only in PEG-treated rats. At study end, DTI showed disappearance of the transection gap in the treated animals vs an enduring gap in controls (fractional anisotropy/FA at level: P=.0008). CONCLUSIONS: We show for the first time in an adequately powered study that the paralysis attendant to a complete transection of the spinal cord can be reversed. This opens the path to a severance-reapposition cure of spinal paralysis, in which the injured segment is excised and the two stumps approximated after vertebrectomy/diskectomies.

A cross-circulated bicephalic model of head transplantation.

AIMS: A successful cephalosomatic anastomosis ("head transplant") requires, among others, the ability to control long-term immune rejection and avoidance of ischemic events during the head transference phase. We developed a bicephalic model of head transplantation to study these aspects. METHODS AND RESULTS: The thoracic aorta and superior vena cava of a donor rat were anastomosed with the carotid artery and extracorporeal veins of a recipient rat by vascular grafts. Before thoracotomy in the donor rat, the axillary artery and vein of the donor were connected to the carotid and the extracranial vein of the third rat through a silicone tube. The silicone tube was passed through a peristaltic pump to ensure donor brain tissue blood supply. There is no ischemia reperfusion injury in donor brain tissue analyzed by electroencephalogram. Postoperative donor has pain reflex and corneal reflex. CONCLUSIONS: Peristaltic pump application can guarantee the blood supply of donor brain tissue per unit time, while the application of temperature change device to the silicone tube can protect the brain tissue hypothermia, postoperative experimental data show that there is no brain tissue ischemia during the whole operation. The application of vascular grafting can also provide the possibility of long-term survival of the model.

HEAVEN: The Frankenstein effect.

The HEAVEN head transplant initiative needs human data concerning the acute restoration of motor transmission after application of fusogens to the severed cord in man. Data from two centuries ago prove that a fresh cadaver, after hanging or decapitation, can be mobilized by electrical stimulation for up to 3 hours. By administering spinal cord stimulation by applied paddles to the cord or transcranial magnetic stimulation to M1 and recording motor evoked potentials, it should be possible to test fusogens in fresh cadavers. Delayed neuronal death might be the neuropathological reason.

Brain protection during cephalosomatic anastomosis.

Cephalosomatic anastomosis requires neuroprotective techniques, such as deep hypothermia, to preserve brain activity. Despite the failure of pharmacologic neuroprotection, new strategies, including ischemic pre- and postconitioning and the use of Perftoran, have to be explored to complement hypothermia. This article summarizes the field of brain protection during CSA and these promising strategies.

Neurologic foundations of spinal cord fusion (GEMINI).

Cephalosomatic anastomosis has been carried out in both monkeys and mice with preservation of brain function. Nonetheless the spinal cord was not reconstructed, leaving the animals unable to move voluntarily. Here we review the details of the GEMINI spinal cord fusion protocol, which aims at restoring electrophysiologic conduction across an acutely transected spinal cord. The existence of the cortico-truncoreticulo-propriospinal pathway, a little-known anatomic entity, is described, and its importance concerning spinal cord fusion emphasized. The use of fusogens and electrical stimulation as adjuvants for nerve fusion is addressed. The possibility of achieving cephalosomatic anastomosis in humans has become reality in principle.