Arthritis breakthrough: 3-D printer and stem-cell solution used to create cartilage
Breakthrough research by a university team creates replacement cartilage using a solution of patients’ stem cells and a 3-D printer
Getting a grip on arthritis
Her foot pain began 15 years ago, leading to a 2002 diagnosis of osteoarthritis, which left her limping and unable to walk for extended periods of time. And it progressively worsened.
In time, Deborah Cole Thomas, 60, of the US state of Pennsylvania, would undergo operations to fuse joints in both feet along with a left-ankle replacement, all from the wear-and-tear form of arthritis. She endured shoulder pain and more recent problems with right-knee pain, which she likens to being stabbed with a knife. Round-the-clock pain medication is a must.
Deborah Cole Thomas“I try not to let it affect me,” Thomas said, noting that her husband, Llewellyn, 82, has had both arthritic knees replaced. “It drives me to keep moving. I watched my mom give up, and her hands became so crippled she had to be fed.”
Thomas, now retired, worked as a computer engineer, spending hours at a desk that made her “feel like the Tin Man in The Wizard of Oz“. She’d stand and struggle to flex stiffened joints.
In coming years, she faces further operations, including knee replacement. But she’s still walking, with a goal of 10,000 steps a day and an average of 7,000.
She can’t run and isn’t allowed to jump. Doctor’s orders. But she works around the limitations. “There’s always something I can do just to keep moving.”
While people with osteoarthritis struggle to move, there’s plenty of movement in research as scientists work through the biological puzzle of osteoarthritis to come up with potential treatments.
A University of Pittsburgh research team, led by Rocky Tuan – professor and executive vice- chairman of the department of orthopaedic surgery and director of the Centre for Cellular and Molecular Engineering – is making headway in understanding the complex stew of enzymes, proteins and genes that cause osteoarthritis while identifying a potential treatment to slow the rate of cartilage destruction.
There’s further breaking news from the Tuan camp that sounds like science fiction: his team is using a 3-D printer, which makes structures one layer at a time, to make new joints. Using a solution containing the patient’s stem cells, along with growth factors and scaffolding material, the 3-D printer constructs actual cartilage in the right shape to replace damaged cartilage.
The stem-cell solution extruded through a catheter could also be used to create new cartilage, as guided by a 3-D printer, directly onto the joint bone.
The team’s tissue-engineered joints have already shown success in large animals, raising the promise of creating replacement joints for people now dependent on plastic and metal ones. The process could be particularly useful in repairing battlefield injuries.
Tuan announced the success on April 27 at the Experimental Biology 2014 scientific sessions and meeting in San Diego.
“We essentially speed up the development process by giving the cells everything they need, while creating a scaffold to give the tissue the exact shape and structure that we want,” Tuan said, adding that his team continues working to develop cartilage more closely resembling human cartilage.
“Total joint replacements involving plastic and metal joints work well, but they don’t last long enough,” Tuan said. “For someone who is 60, that’s OK. But if you are in your 30s, that’s not good because you may need revision after revision.
“We are not in a position to say that it will last a lifetime. Time is the true test,” Tuan said of the tissue-engineered joints his team has created. “I can only say it’s very promising and is looking good.”
Joints, the business end of bones, include a covering made of flexible and protective cartilage to prevent damage from friction. But chronic wear and tear from overuse, traumatic injury or bone misalignment, among other factors such as obesity, promotes a biological process, not yet fully understood, that degrades cartilage.
Osteoarthritis represents 80 per cent of all cases of arthritis, whose various forms plague 27 million Americans, making arthritis the nation’s major form of physical disability. The disease is particularly widespread in the elderly, with one out of two individuals older than 65 having at least one joint affected.
There’s even more news that could advance treatments for osteoarthritis.
The University of Pittsburgh team is also using tissue engineering to develop human tissue and cartilage in a laboratory dish that can be used to test the effect of drugs. The live model of human joint tissue is being heralded as the creation of “the first example of living human cartilage grown on a laboratory chip”.
For now, the engineered cartilage tissue on a computer chip will serve “as a test-bed for researchers to learn about how osteoarthritis develops” and to develop new drugs.
“We hope that the methods we’re developing will really make a difference, both in the study of the disease and, ultimately, in treatments for people with cartilage degeneration or joint injuries,” said Tuan, who also serves as director of the McGowan Institute for Regenerative Medicine and director of the Centre for Military Medicine Research at the University of Pittsburgh School of Medicine.