A new hybrid 3D printer can manufacture implantable cartilage by combining ink-jet technology with electro-spun polymers.
Many afflictions, including Osteoarthritis, are largely caused by the degradation of cartilage in the joints. Unfortunately, cartilage has very limited healing capacity – once it's damaged, or gone, there's usually little the body can do naturally to replace it. In recent years, science has found ways to compensate, and efforts have been made to regrow the tissue using a variety of methods, including a bio-active "hydrogel" which induces tissue regrowth, and biodegradable nanofiber spheres which can carry new cells to wounded areas of the cartilage to help it heal properly. Now, scientists at the Wake Forest Institute for Regenerative Medicine in North Carolina, have created a new method, by way of a 3D printer which can make artificial and implantable cartilage.
This is how the cartilage printer works
3D bio printers have already been implemented to create artificial arteries, but the process of creating cartilage is a little different and has to use a combination of technologies in order to manufacture a material that would properly fulfill it's function. The unique technology which must be implemented is called electro-spinning, where an electric current is used to create fine strands of polymer fiber. The fiber acts as a porous base, a sponge to put it simply, into which cartilage cells can be injected and stabilize as a solid structure. The fiber also acts as a reinforcement for the finished cartilage structure, lending it more stability than previous efforts.
The team of scientists, led by Professor James Yu, extract the cartilage cells from rabbit's ears, and then inject them into the electro spun material by means of inkjet printing. As with other 3D printing technologies, thin layers of electro spun mat and cartilage cells are layered on top of each other, until a finished structure has been completed. The resulting cartilage disc, which is completely implantable, is 10cm in diameter and 4mm in thickness.
The finished cartilage pieces were stress tested to see how they would handle wear and tear. Some implants were also tested on mice. After several weeks, the implants had assumed properties expected of natural cartilage. It may thus one day prove successful in humans as well.