TWU graduate creates nanomaterial that could help repair spinal cord injuries
Listen to William Sikkema explain the science behind Texas-PEG on CBC’s Quirks and Quarks.
A doctoral student from Langley has created a nanomaterial that could be life-changing for people with spinal cord injuries. The discovery was published in Surgical Neurology International today.
William Sikkema graduated from Trinity Western University in 2014 and is currently completing a PhD at Rice University in Texas. He has synthesized a material called Texas-PEG, which is a functionalized type of graphene nanoribbons meant for medical use.
The customized nanoribbons have succeeded in restoring function in rat models whose spinal cords were severed in a procedure performed at Konkuk University in South Korea. Only 24 hours after their spinal cords were severed, rats showed some electrical connection between the brain and body. Almost full motor movement—90 per cent—was restored after only two weeks of recovery, and 95 per cent after three weeks. Previous experiments, without the nanoribbons, saw only about 10 per cent recovery of motor control after four weeks.
“Most scientific research is very incremental,” said Sikkema. “Having 95 per cent mobility recovery is night and day.”
The PEGylated graphene nanoribbons are soluble in both water and polyethylene glycol (the original PEG), a biocompatible polymer used in surgeries, pharmaceutical products, and other biological applications.
The project began when Sikkema read about work by an Italian neurosurgeon, Sergio Canavero, who hopes to perform the world's first full-body transplant. Sikkema thought water-soluble graphene nanoribbons might enhance Canavero's GEMINI protocol, which depended on PEG's ability to promote the fusion of cell membranes by adding electrical conductivity and directional control for neurons as they spanned the gap between sections of the spinal cord.
The challenge with Canavero’s original protocol was connectivity for the neurons. Sikkema’s Texas-PEG solves the problem:
“Neurons grow on graphene nanoribbons very nicely because they’re electrically conductive,” said Sikkema. “But people who have grown neurons on patterns of graphene nanoribbons have done this only in petri dishes. So we took that graphene nanoribbon and then polymerized water soluble groups off the sides. We started with this straw-like structure that was not water soluble, but once the straw was split lengthwise into a ribbon, it gained edges that polymers could be grown from, making it water soluble. Then we put that into a three-dimensional tissue setting, and the neurons grew on that.”
Sikkema has a hockey analogy to describe the phenomenon of Texas PEG in layman’s terms:
“We think electrical conductivity across the gap is really important for the growth of neurons, so we needed a conductive path. Imagine the gap in the spinal cord as a hockey rink, and the electrons are miniature people trying to cross the rink without touching the ice. Normal conductive materials are like hockey pucks, and you’d need to cover a lot of the surface by throwing pucks down at random to get a path for the person to cross. Graphene nanoribbons are long and thin, like hockey sticks lined up across the rink so the person can cross from one side of the rink to the other. You don’t need to cover a lot of the ice with sticks to be able to bridge the gap.”
Now that his Texas-PEG has proven successful in rats, Sikkema’s team, including his supervisor at Rice, James Tour, will soon create the materials for use in an experiment involving dogs, and later monkeys. If they are successful, Sikkema hopes surgeons will able to use the materials in humans soon afterward.
“I don't want to give any false hope for people with spinal cord injuries,” he said. “Rodents are a little more robust than humans with regards to their nervous system. They can regenerate a little more easily than humans. If the monkey trial works, I'm cautiously optimistic for this in humans.”
Former TWU prof taught Sikkema ‘to be a scientist’
The professors who taught and mentored Sikkema at Trinity Western University during his undergraduate degree are impressed, but not particularly surprised about his creation.
Julia Mills, an associate professor of biology at TWU, says his success is well earned. “William stood out from the very beginning,” she said. He was one of those people who didn’t really see obstacles. He saw possibilities.”
Sikkema worked for Mills as a lab researcher during his time at TWU. One summer, he wanted to study the effects of a particular cancer drug. To answer his question, he needed to use a newer technique called mass spectrometry —so he helped introduce it to her lab.
Sikkema said the freedom she gave him to explore and ask questions was invaluable. “She really pushed me,” he said. “She taught me to be a scientist.”
Another one of William’s professors who is especially proud is Dr. Arnold Sikkema, a professor of physics at TWU. He also happens to be William’s father.
Arnold says he first heard about William’s idea during a late-night phone call, and wasn’t particularly surprised, explaining that William is always full of ideas. “Talking to William on the phone is like a hurricane,” he says with a laugh. “He just tells us everything he’s just figured out at super top speed.”
Fortunately, both Arnold and his wife are scientists, and have little trouble keeping up. William credits them with making him look at the world through scientific eyes.
“He thrives in the lab. That’s his element. When living at home, we had to put a sign on the microwave after a while that said ‘No experiments in here!’” says Arnold. “Some parents want their kids to be like them, but I don’t. I want my kids to be far better. I just know that he’s got much more depth and intuition than I ever had, and the breadth of his training is superior.”
In addition to taking all of the chemistry he needed for a chemistry major at TWU, William took as many biology and physics courses as he could, often taking seven or eight courses per semester instead of the standard five.
“Having both biology and chemistry, and a little bit of physics, really allows me to build collaborations here, and think about things that go unnoticed by pure chemists or biologists,” William says.
William credits Dr. Chadron Friesen for instilling in him a love of organic chemistry, which is a crucial component of nanotechnology.
For Friesen, seeing William make this contribution to medical research is “humbling.”
“It’s definitely a pleasant surprise, but humbling as well,” Friesen said. “An instructor can make an impact.”
William agrees, saying he’s thankful for his time at TWU—as a small university, it’s able to offer each student more access to specialized equipment and professors. He says he’s also thankful for the faculty who pushed him, and gave him the freedom to ask questions.
What’s next? “I’ll go wherever the research leads,” he says.