Infrared light therapy for spinal cord injury recovery reaches milestone

Patients with Spinal Cord Injury (SCI) may benefit from future treatments aimed at restoring nerve connections using red and near-infrared light.

The method, developed by scientists from the University of Birmingham, UK, and patented by the University of Birmingham Enterprise, involves delivering light directly to the site of damage.

Recent studies published in the journal of Bioengineering and Translational Medicine have identified the optimal “dose” for this new therapeutic approach and show that it can produce significant therapeutic improvements, including significant restoration of sensitivity and movement, as well as regeneration of damaged nerve cells.

Researchers led by Professor Zubair Ahmed used cellular models of SCI to determine the frequency and duration of light required to achieve maximum restoration of function and stimulation of nerve cell growth.

They found that delivering 660 nm red light for one minute per day increased cell viability (a measurement of the number of living cells) by 45% over five days of treatment.

Professor Ahmed said: "Excitingly, this aspect of the study showed that the effect of 660nm light was both neuroprotective, which improved the survival of nerve cells, and neuroregenerative, which stimulated the growth of nerve cells."

The researchers also studied the effect of light therapy in preclinical models of SCI. Here they used two different methods: an implantable device and transdermal delivery, in which a light source is placed on the skin.

Their study showed comparable results for both delivery methods: a dose of 660 nm light delivered daily for one minute for seven days resulted in reduced tissue scarring at the site of injury and significant functional recovery.

The researchers also found a significant reduction in both cavities and scarring, as well as increased levels of proteins associated with nerve cell regeneration and improved connections between cells in the damaged area of the spinal cord.

This is the first time transdermal and direct light delivery have been compared in SCI, and the results are an important milestone for the researchers, who have already received additional funding and plan to develop an implantable device for use in people with traumatic SCI, where there are currently no methods, preserving cells or improving neurological function.

Andrew Stevens, first author of the study and registrar of neurosurgery, explains: “Surgery after spinal cord injury is common, but currently these operations only aim to stabilize damage to the spinal bones caused by the injury. This concept is incredibly exciting because it could offer surgeons the opportunity, during the same surgery, to implant a device that could help protect and repair the spinal cord itself."

Professor Ahmed continues: “To make light therapy a viable treatment for SCI in humans, an implantable device will be required to provide direct visibility into the damaged tissue and allow greater precision and standardization of dosage without being hampered by the thickness of the skin and other tissue surrounding the spinal cord.

Photobiomodulation (PBM) may provide a viable therapeutic approach using red or near-infrared light to promote recovery after SCI by mitigating neuroinflammation and preventing neuronal apoptosis. Our current research is aimed at optimizing PBM dosing regimens and developing and validating the effectiveness of an invasive PBM delivery paradigm for SCI."

The research team is now looking for commercial partners or investors to take the next steps to develop a prototype device that can be used in the first human clinical trials.