Preclinical Services Offered

RATIONALE

VPC NeuroTherapeutics Inc. invented the cure for disease initiated by spinal cord disease.  This treatment restores neurologic function in spinal cord injury (SCI) patients. This is the time to address the optimization of neurologic recovery by reconstructing the white matter lost in the SCI trauma itself.

Axonal regeneration in ascending and descending pathways across the SCI lesion will require:

  1. Inhibition and elimination of a severe, destructive inflammation initiated by SCI.  This has been achieved by VPC NeuroTherapeutics Inc. with administration of hop xanthohumol (XN) in SCI rats in extensive preclinical studies.  A clinical study lead by Dr. Dabrowski in Poland using an optimal dose of hop XN determined by VPC NeuroTherapeutics Inc., indicates that all treated SCI patients experience recovery of neurologic deficits.  Thus, we have the cure.  VPCnt-101 (synthesized XN), the lead compound is being developed by VPC NeuroTherapeutics Inc., for regulatory approvals for the first effective treatment of disease initiated by SCI.

  2. Implantation into the SCI lesion of a functional bridge for axonal regeneration.  Such a bridge must be: (i) very soft and porous, a hydrogel or hydrogel-like, (ii) biocompatible with the spinal cord = does not induce inflammatory response leading to rejection after implantation, (iii) axons must enter it, inhabit it and persist for integration with the spinal cord surrounding the lesion.

  3. Myelin sheaths in the spinal cord distal to the SCI lesion must be safely removed in areas targeted for axonal regeneration for a period of time required for axonal regeneration.  This has been achieved by intraspinal infusion of kynurenic acid in recent studies by Dr. Kwiecien.

THE BRIDGE

While there is a very large and un-tapped market for a functional bridge enabling axonal regeneration across the SCI, TBI or lesion post-cerebral infarct in stroke, it does not yet exist.

Dr. Kwiecien tested 25 different acellular materials in the dorsal columns crush SCI model in the LES (Long Evans Shaker) rat and found that 24/25 were rejected by inflammatory reaction of varying severity by the implanted spinal cord. One material, a modified methalcrylate was spinal cord compatible and was not rejected but axons did not enter it.

 

WHY LES RAT?

  • This model is very convenient to study neuroregeneration in vivo.  Normally myelinated models are not.

  • This mutant of myelin basic protein lacks myelin in its central nervous system (CNS), therefore: (a) a lesion to the spinal cord results in moderate and self-limiting inflammatory response apparently of no consequence to regenerating axons supported by implanted choroid plexus across the SCI lesion, (b) the lack of myelin allows for axons that crossed the implanted lesion to keep elongating unhindered in the distal segment of the spinal cord.

  • Implantation of the acute SCI lesion in the LES rat with rat choroid enabled ascending axons in the dorsal column to cross the lesion, elongate withinin bundles of undamaged axons along 2/3 of the length of the spinal cord, ~5cm and, receive myelin sheaths at 8 weeks post-SCI. Thus novel white matter was re-created and integrated with undamaged spinal cord around the SCI lesion.

  • After a bridge that is biocompatible with the spinal cord and allows for axons to enter it, cross it and persist in it, long term studies to characterize integration of newly reconstructed white matter with peri-lesional spinal cord can be performed in the LES rat.

This study provides a proof of principle that a bridge, whether synthetic or cellular, perhaps both, in combination, can be successfully tested in the LES rat SCI model. Such a bridge is necessary for neuroregeneration since regenerating axons don’t swim across water-filled SCI lesion.

SPECIFIC SERVICES 

BIOCOMPATIBILITY WITH THE SPINAL CORD STUDY:

1.    Mature, 3-4 month old LES rats

2.    Neurosurgery: dorsal laminectomy with dorsal column crush

3.    Implantation of sterile experimental material contributed by the sponsor into the SCI crush lesion

4.    Post-surgical recovery and supportive care, for 7 days post-SCI

5.    Whole body perfusion, formalin, dissection of the spine

6.    Decalcification

7.    Histologic examination of the implanted SCI lesion, microphotography for documentation

8.    Study Report including interpretation of histologic analysis.

 

SUPPORT OF AXONAL REGENERATION BY A BIOCOMPATIBLE MATERIAL IMPLANTED IN THE SCI LESION:

I.      1 – 4. As above.

II.    On day 6 post-SCI, injection of a fluorescent dextran tracer into both sciatic nerves.

III.  Whole body perfusion, 4% paraformaldehyde (PFA), dissection of the spine.

IV. Decalcification

V.   Fluorescent microscopy analysis of the implanted lesion. Microphotography of regenerating fluorescent-traced axons for documentation.

VI. Study report including interpretation of fluorescent analysis.

 

LONG TERM STUDY ON SUPPORTIVE EFFECTS FOR NEUROREGENERATION BY A SUCCESSFUL CANDIDATE BRIDGE. (preclinical efficacy study):

A.   Material, cell preparation or material seeded by cells in vitro prior to implantation of the SCI lesion in the LES rat.

B.   Survival period, up to 8 weeks

C.   Examination intervals: 3, 5, 7, 14, 28, 42, 56 days post-SCI.

D.   For histology and electron microscopy analyses: perfusion with Karnowski’s fixative.

E.   For fluorescent microscopy of axonal regeneration traced by dextran: perfusion with 4% PFA.

F.   Study report.

 

STUDY QUOTES PROVIDED UPON REQUEST.

Please, contact Dr. Kwiecien:

jmkwiecien@vpcneurotherapeutics.com

mobile: 1-289-237-6964