Biodegradable surgical implants and surreptitious DNA archival.

Mar 04, 2010

After badly breaking a load-bearing part of your body it's not uncommon for an orthopedic surgeon to install a couple of after-market bits of hardware to hold the bones together while they knit. This usually takes the form of a couple of titanium alloy screws, though plates, rods, and tubes are not unknown. The downside of using something made out of metal to put things back together is that the screw holes left behind after the implants are removed require additional time to heal. Plus, the holes further compromise the structural integrity of the bone until they fill in. In the future this may be less of an issue - scientists at the Fraunhofer Institute of Bremen, Germany have figured out how to make surgical screws out of a biodegradable composite called hydroxylapatite. Hydroxylapatite, incidentally, comprises approximately one half of the composition of bone. Anyway, the idea is that the screws are installed during surgery and left in place rather than removed later. As the bone regenerates it grows around the bioactive components and incorporates them into its structure, thus hopefully reducing the risk that the bone will be stronger than it otherwise would be after healing.

About a month ago I wrote an article about newborn children being tested for genetic diseases at birth and the possibility that the data might wind up in the hands of someone unexpected. It should come as no surprise that this has happened. The Texas Tribune discovered during the course of an investigation that approximately 800 samples were given to a military research program without anybody knowing about it. It turns out that the project is called AFDIL (Armed Forces DNA Identification Library) and was part of an effort to bootstrap a mitochondrial DNA database. There are a couple of things about mtDNA that should be kept in mind - it has only around 16,500 base pairs, which codes for 37 genes. There isn't a whole lot of room for variation there. Then again, there can be a lot of variation of mtDNA between tissues of the same person, let alone a group of people, so its use as an identification technique is questionable at best. The really worrisome thing is how far the powers that be went to keep this quiet, from settling out of court before the discovery phase of the lawsuit to various and sundry dodges and excuses to keep from having to get consent.