Lifting weights is part of Kris Boesen’s regular program of physical therapy.



On March 6, 2016, just before Kris Boesen’s 21st birthday, his car skidded across a wet road in Bakersfield, California and slammed into a telephone pole. He broke bones in his neck and suffered a traumatic injury to his cervical spine that left him paralyzed from the neck down. However, thanks to a bit of luck and timing, he qualified for a current clinical trial conducted as a partnership between Rancho Los Amigos National Rehabilitation Center and Keck Medicine at the University of Southern California (USC), headed up by Charles Liu, director of the USC Neurorestoration Center. Today, Kris can move his arms and hands, operate his motorized wheelchair, breathe on his own—and even feel some sensation below the waist.

In April, just five weeks after his accident, researchers injected an experimental dose of 10 million AST-OPC1 cells into Kris’s cervical spinal cord. These AST-OPC1 cells were developed by Asterias Biotherapeutics, in Fremont, California from embryonic stem cells, which they converted into oligodendrocyte progenitor cells (OPCs) normally found in the brain and spinal cord of healthy bodies.

When a spinal cord injury occurs, Liu tells mental_floss, “The neurons can die, the axons can be severed, or the myelin can be damaged.” These AST-OPC1 cells have been designed to address the myelination and are neuroregenerative—that is, they can restore connections and tissue within the spinal cord, thus potentially restore feeling and movement to the limbs.

“Quite frankly, my expectations were not very high,” Liu says. “People have been talking about regenerative medicine for a while now, but in the nervous system we haven’t had a whole lot of success.”

Charles Liu, director of the Neurorestoration Center at the University of California

Kris has what is known as a grade A injury on the ASIA scale (American Spinal Injury Association). This means he couldn’t move anything more than the smallest shrug of the shoulders at the neck line, and nothing from the neck down. Rodney Boesen, Kris’s father, tells mental_floss that he recalls Liu saying he hoped that at most Kris might be able to move from a grade A injury to a grade B, which means he'd regain some feeling below the neck. “The real key word there was hope,” says Rodney.

Six weeks after the stem cell therapy, Kris left the hospital. And now, just five months after the treatment, hope has become a reality: Kris has surpassed everyone’s expectations and “moved up two additional motor levels,” says Liu, which he calls “extremely significant," adding, “Think of all these patients that are quadriplegic: they’re basically not able to move their arms or legs. Now you can turn them into patients who can actually brush their teeth and do stuff for themselves.”

Indeed, Kris can now do most everything with his hands and arms that someone without a spinal cord injury can do: brush his teeth, feed himself, write his name, text his girlfriend, and even lift weights, which is an important part of his physical therapy.

Liu says Kris’s improvement “is very atypical in natural improvement or just rehabilitation alone. He had no improvement at all until he got the cells,” he says. He expects Kris will continue to improve.

Kris Boesen and his father, Rodney

Even more encouraging, says Kris’s father, “There’s sensation going on below his waist.” This is how his doctors realized recently that he had a bladder infection; Kris could feel it. Most people with spinal cord injuries of his kind wouldn’t be able to. Moreover, Rodney says, “The stem cells have given him back a lot of functions,” including breathing without a ventilator, coughing, and even sweating. Sweating, which most people take for granted (and don't especially enjoy), is a process that most para- and quadriplegics can no longer do, as it requires the spinal cord to send signals to the sweat glands. This is another promising sign that Kris’s treatment has had a regenerative effect.

He has also had involuntary movement in his feet and some sensation returning in his knees and thighs. “The nurses noticed when you touch his legs that they’re warm," Rodney says. "They told me that it’s unusual for people with his injury to have warm legs because they have such a problem regulating their body temperature."

Rodney credits Liu for “moving heaven and Earth” to get Kris into the trial.

Liu is encouraged by Kris’s results and feels that the new "biological engineering" technologies emerging to treat spinal cord injuries— such as cell transplantation, new prosthetics, and brain wave interface processing—will come together to make huge strides “toward restoring function in either a conventional or unconventional way," Liu says. "It’s really exciting.”

Kris was not up for an interview at this time, but in a statement provided by Keck Medicine, he said, “Just because you went through something bad doesn’t mean you have to suffer the rest of your life … now, thankfully with technology, we have some stuff that’s working, and it’s obviously worked for me so far.”

The initial results of this ongoing trial, which includes six patients at six sites across the United States, will be published sometime in September.

All images: Greg Iger/Keck Medicine of USC