It doesn’t look much, this slab of intersecting gelatinous green-orange cylinders. But in fact it’s a new stretchable hydrogel, that could be used to create 3D printed medical implants—such as replacement cartilage for noses or ears.
The material has been created in a collaboration between researchers at MIT, Duke University, and Columbia University. The material is made from two key polymers which hold together a network of water molecules. One of the polymers provides the material with highly elastic properties, while the dissipates large amounts of energy—meaning the material as a whole can deform dramatically without breaking.
The material is benign as far at the human body is concerned, making it suitable for use in medical implants. But its material properties can also be tweaked at the macro level by building structures using 3D printing. Addition of a safe nano-clay to the mix allows the team to alter the viscosity of the hydrogel, making it possible to 3D-print it into lattices such as the one above. In fact, when 3D printed in such a way, the structures can be compressed by 99 percent and yet still spring back into their original shape when released.
Its high strength and elasticity make it a worthy alternative to human cartilage, which usually acts as a kind of shock absorber in our body—in knee joints, noses and the like. The team hope that the new material could be used to print replacement pieces of cartilage, which when laced with human stem cells would neatly integrate into the body.
The only sticking point right now is that the resolution of the printed samples is half a millimeter. That’s perhaps good enough for humans, but a little too coarse to test the technique in the animal models, like mice, that scientists would naturally turn to first. So right now, they’re trying to up the resolution—and the result could be a very precise new nose indeed. [Advanced Materials via PhysOrg]