Chennai: A study by researchers at Tamil Nadu Veterinary and Animal Sciences University (TANUVAS) and Nichi-In Centre for Regenerative Medicine (NCRM) offers new hope of treating millions of people inflicted with spinal cord injury.

Spinal cord injury is a devastating condition with millions around the world afflicted. The present approaches to treat spinal cord injury have met with only little success. Cell based therapies offer great promise to this condition and there are several clinical trials using different cell sources to treat spinal cord injury.

Adult stem cells derived from bone marrow are of particular interest due to their multipotent nature and proven potential in the repair, regeneration, rejuvenation and restoration of damaged organs including liver and heart.

In recent years, a number of studies have proven the efficacy of bone marrow derived stem cells in the repair and regeneration of nerve tissue, especially in spinal cord injury.

This new study shows the efficacy of transplantation of bone marrow derived stem cells in a novel polymer scaffold, by promoting recovery of functions in a dog with spinal cord Injury which was followed up for two years.

The scaffold used in the study is thermo-reversible gelation polymer (TGP), which is a hydrogel with unique properties making it highly suitable for growing cells in it and is biocompatible to be implanted inside the body.

In vivo implantation of stem cells embedded in TGP has been proven to be safe and efficacious in animal studies earlier. In central nervous system injury, the study by Osanai T and colleagues is the forerunner to the present study. In that study, bone marrow stromal cells (BMSC) were embedded in TGP and implantation of this BMSC-TGP construct in the mice subjected to cerebral infarct was compared with two other study groups, BMSC without TGP group and PBS (phosphate buffered saline) group. The results proved that the TGP hydrogel completely disappeared and provoked no inflammation in the brain of the mice. Further the transplanted cells were widely engrafted around the cerebral infarct in the BMSC-TGP construct treated mice and the number was larger than the BMSC without TGP group. “This study established that use of a scaffold along with cells is more advantageous in vivo than injection of cells alone and this formed the basis of our study in a large animal with spinal Cord Injury,” say the researchers of the new study.

The dog included in the new study was a six month old, congenitally deaf boxer breed dog, which was admitted to TANUVAS with Grade IV paraplegia with total loss of motor and sensory functions of the hind limbs including loss of bladder and bowel function due to a road traffic accident. Under general anaesthesia following myelography, autologous bone marrow aspirate was collected from femur of the dog with compressed fracture of Thoracic vertebra 12 (T12) and dislocation between T11 and T12 and the aspirate was transferred to the cell processing unit of NCRM. The aspirate was subjected to cell processing using established protocols and bone marrow mono-nuclear cells (BMMNCs) were isolated. A portion of the BMMNCs was embedded in TGP and was engrafted intralesionally. After 19 days, a portion of the isolated BMMNCs, which was separately stored, was also administered intravenously to potentiate the cell transplantation and the animal was followed up with a regular follow-up for a period of two years.

“The recovery of motor and sensory functions was noticed on the 53rd day. The animal attempted to stand on the 79th day and ambulation was possible on the 98th day. The animal was able to walk satisfactorily on the 133rd day and thereafter the animal returned to its normal life and the status has been maintained constant for the past two years,” say the researchers.

The above clinical protocol for spinal cord regeneration evolved by TANUVAS – NCRM was published in the journal Stem Cell Research & Therapy with the comment “the finding is encouraging since spinal cord injuries are common conditions in humans and lack effective therapies”. According to the researchers, this study is one of its kinds in the world and will serve to bridge the gap between veterinary and human sciences with the hope of treating millions inflicted with spinal cord injury.