Engineered human stem cells have been used to enable paraplegic rats to walk independently and regain sensory perception. The implanted rats had some healing in their spinal cords.
Led by Dr. Shulamit Levenberg, of the Technion-Israel Institute of Technology, the researchers implanted human stem cells into rats with a complete spinal cord transection. The stem cells, which were derived from the membrane lining of the mouth, were induced to differentiate into support cells that secrete factors for neural growth and survival.
The work involved more than simply inserting stem cells at various intervals along the spinal cord. The research team also built a three-dimensional scaffold that provided an environment in which the stem cells could attach, grow and differentiate into support cells. This engineered tissue was also seeded with human thrombin and fibrinogen, which served to stabilize and support neurons in the rat’s spinal cord.
5 of 12 rats (42%) treated with the induced constructs demonstrated BBB scores exceeding 17, a compiled reflection of improved coordinated gait, plantar placement, weight support, recovery of toe clearance, trunk stability, and predominant parallel paw and tail position, suggesting regained cortical motor control.
The induced constructs promoted remarkable recovery in 42% of the rats, and show no efficacy in the remainder of the rats within the same group. This binary effect compels further investigation, since understanding of the underlying mechanisms causing substantial improvement in some animals and no practical improvement in others can render this method into an effective treatment.
Spinal cord injury (SCI), involving damaged axons and glial scar tissue, often culminates in irreversible impairments. Achieving substantial recovery following complete spinal cord transection remains an unmet challenge. Here, we report of implantation of an engineered 3D construct embedded with human oral mucosa stem cells (hOMSC) induced to secrete neuroprotective, immunomodulatory, and axonal elongation-associated factors, in a complete spinal cord transection rat model. Rats implanted with induced tissue engineering constructs regained fine motor control, coordination and walking pattern in sharp contrast to the untreated group that remained paralyzed (42 vs. 0%). Immunofluorescence, CLARITY, MRI, and electrophysiological assessments demonstrated a reconnection bridging the injured area, as well as presence of increased number of myelinated axons, neural precursors, and reduced glial scar tissue in recovered animals treated with the induced cell-embedded constructs. Finally, this construct is made of bio-compatible, clinically approved materials and utilizes a safe and easily extractable cell population. The results warrant further research with regards to the effectiveness of this treatment in addressing spinal cord injury.