For all of technology’s efforts to improve upon nature, sometimes the most challenging feat is simply matching it, or even coming close. Take, for example, the endlessly versatile muscle, or the light and load-bearing bone. Imitating the latter poses a unique problem for surgeons repairing damaged, aging or diseased bones in humans, leaving us with metal or ceramic replacement parts that are imperfect or intolerable to a patient’s system, often needing to be replaced with painful and debilitating surgery. A solution to that mismatch may be on the horizon, as researchers in Italy have turned right back to nature, albeit a different kingdom, to find what may sound like an archaic bone replacement—wood. Rattan, to be specific, a flexible palm wood used in furniture and baskets.
In William Gibson’s Zero History, a novel laced with technology just barely within reach, one unlucky daredevil is the beneficiary of such a rattan bone replacement after a base-jumping stunt gone awry.
“Rattan. The stuff they weave baskets and furniture out of. They’ve found a way to turn it into a perfect analog of human bone.”
“You’re making that up.”
“They’re just starting to test it on humans. On me, in fact. Works a charm on sheep.”
“They can’t. Turn that into bone.”
“They put it into ovens. With calcium, other things. Under pressure. For a long time. Turns to bone, near enough.”
“If I’d thought of it, I’d have had them make you a basket. Brilliant thing about it, you can build exactly the bone you need, out of rattan. Work it as rattan. Then ossify it. Perfect replacement. Actually a lot stronger than the original. Microscopic structure allows the blood vessels to grow through it.”
While published research describes the technology as just on the brink of human trials in 2013, and likely still a few years away from human benefit, Garreth’s description is pretty accurate. On a fast read, it brings to mind a springy bamboo graft, but after the 10-day transformative process, the rattan turns into something that looks a bit like a piece of sidewalk chalk.
That’s because the repeated heat and pressure actually strip the small chunks of wood of many of their biological elements like celluloseand lignin. Remaining is the carbon skeleton, which are then pumped with more appealing substances like calcium, oxygen and phosphate to match the density and strength of bone.
The important part of the product, even when baked and treated to turn it into something quite different from its original self, is the microscopic structure. Even more than other types of wood, rattan is remarkably similar in density and is porous. As a result, blood and nerves can actually travel through the material much like they do in bone. Surgeons reality checking the technology have found that, in the first patients (some Italian sheep), the attached bone begins to actually fuse to the rattan implant, leaving it difficult to tell where one starts and the other ends.
Combined with strength and, despite the lengthy procedure, affordability, and doctors involved in early studies have called the rattan implants a “holy grail” for orthopedic patients.
The rattan implant isn’t the only innovation in artificial bone working its way toward reality. British scientists have experimented with injectable bone, a toothpaste-like substance that can squirt to the site of an injury, then harden while simultaneously delivering stem cells to site of repair. Berkeley scientists have also attempted to mimic the layered structure found in mollusk shells like oysters and abalone for bone replacement.