Scientists are tapping into the power of silkworms and spiders to develop new devices made from silk, and their newest invention can help mend broken bones. Silk is an incredibly strong substance, produced naturally in both spiders and silkworms, and has been used in medicine for years.
Currently, fractured bones are held together with metal screws or biodegradable ones. But metal alloy screws may begin to corrode, which requires a new operation to remove them; meanwhile, biodegradable alternatives may cause inflammation and are difficult to insert into the bone. Silk screws, on the other hand, are a new potential alternative that could be safer and stronger than what has been used in the past.
Samuel Lin at the Harvard Medical School, as well as David Kaplan at Tufts University, decided to undergo research to implement silk screws into the process of healing bones. They first dissolved silk in alcohol, then poured the solution into molds. They baked the molds and thus created the implants, which are extremely durable.
The researchers tested their implants in rats, and found that silk screws are just as effective as metal alloy screws, and just as biodegradable as polymer alternatives, but without any of the unwanted side effects like inflammation. “In vivo assessment in rat femurs shows the screws to be self-tapping, remain fixed in the bone for 4 to 8 weeks, exhibit biocompatibility and promote bone remodeling,” the authors write in the abstract. “[S]ilk-based devices offer numerous advantages including ease of implantation, conformal fit to the repair site, sterilization…and minimal inflammatory response.” They hope clinical trials will begin soon.
Silk provides a wide array of applications and avenues for research; for example, researchers have even toyed with using silk for wires that conduct electricity. Silk’s biodegradable properties allows it to be extremely beneficial in medicine and technology, as this renders it safe for the environment.
Dr. Nick Skaer, the CEO of biomaterials producers Orthox, has been studying the medicinal uses of silkworms and spiders for quite some time. He has found a way to create a liquid form of silk from silkworms, which is then carved into a device, implanted into the body, and used to heal cartilage in the knee. Skaer believes that silk could even be used, in the future, to mend other parts of the body, such as hernias and muscles.
Source: Lin S, Kaplan D. “The use of silk-based devices for fracture fixation.” Nature Communications, 2014.