Monday, February 25, 2013

3-D Printing Medical Implants

The last time I wrote about 3-D printing, it was regarding a use that I was not pleased about - print a gun. But technology is usually neutral which means that good can come from it. And that's the case in a new report the world's first implantable medical device has now been 3-D printed. It's a piece of poly(ether ketone ketone), PEKK, (not be confused with PEEK - poly(ether ether ketone) [*] ) used in skull repairs.

This is no small accomplishment as the final product needs to survive sterilization, and osseointegrate - allow the bone growth mechanisms in the body to incorporate the new material. I've worked with osseointegrative materials before, but they were pretty obvious candidates - hydroxyapatite - a calcium phosphate material which is already pretty close in composition to bone. I had no idea that PEKK could be such a scaffold for bone growth. The skull is a nice place to start as it is easily accessible, and not prone to any of the weight bearing stresses that most other bones in the body are exposed to. But I'm am sure that somebody is already looking at moving elsewhere in the body.

This is the first entry in a whole new world of medical devices. What will be next?

[*] PEKK and PEEK (and others) are poly(aryl ether ketones), a group of high performance polymers that have benzene rings in the backbone, and then ethers/ketones between them. PEEK is the most common and has a repeat unit with 2 ether linkages (and hence 2 "E's" in the name) and a single ketone linkage (hence the single "K"), while PEKK is the opposite - 2 ketone linkages and a single ether linkage.

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