March 8, 2014
I have been very fortunate in my life to have never suffered a major broken bone. Do not get me wrong, I have more than my share of scars, burns, bruising, cracked ribs, destroyed ligaments, concussions, and more. It comes with growing up on a farm, playing rough with friends, being bullied at school, and having more than a decade’s worth of martial arts training under your belt. Even so, I have never had to wear a cast and never had to have any pins or plates put into my body, although that was given to me as an option for my leg. However, though it is not something I have to live with, I have friends who do and I have seen just how greatly that can impact your life. With all of the incredible advances being made in medical technology every single day – it seems – I decided to see what has been done in that particular field lately.
And what I discovered were silkworms.
A team of investigators from Tufts University School of Engineering and Beth Israel Deaconess Medical Center (BIDMC) have found that by using silk harvested from silkworms, they are able to produce better screws and plates to implant into patients who need them for such injuries as broken or fractured bones. Unlike the more commonly used metal plates and screws, silk fibers actually improve bone remodeling after an injury and are able to safely degrade within the body, eliminating the need for any additional surgeries required to remove them. These silk implants also do not have the same risk of inflammation and infection that synthetic fibers pose to patients. In addition, according to Dr. David Kaplan, co-senior author of this project and Tufts chair of biomedical engineering, “One of the other big advantages of silk is that it can stabilize and deliver bio-active components, so that plates and screws made of silk could actually deliver antibiotics to prevent infection, pharmaceuticals to enhance bone regrowth, and other therapeutics to support healing.”
Dr. Samuel Lin, Dr. Kaplan’s co-author on the project, of the Division of Plastic and Reconstructive Surgery at BIDMC and Associate Professor of Surgery at Harvard Medical School, also notes how the silk screws and plates do not show up on x-rays, which makes them ideal for doctors to examine the injury and access the healing.
In order to test the silk protein, the researchers obtained samples from Bombyx mori (B. mori) silkworm cocoons and made plates and screws out of it. The silk is then folded in such a manner that it gives it unique properties of both high strength and versatility. Then, the researchers implanted 28 silk-based screws into six lab rats, testing both the ease of implantation as well as assessing how the rats reacted to them over an eight-week period. What they gleaned from this trail was a positive outcome on both fronts. The silk implants proved very straightforward to insert and there were no major complications with them throughout the test period.
Overall, the use of silk-based implants is showing very favorable results.
Image Credit: Thinkstock