Elderly people often have to undergo surgery to replace their old hip joints with shiny new titanium ones. Unfortunately, these hip implants are not as good as they could be – an estimated 15% of hip replacement surgeries in the USA were for already replaced hips.
Thomas Webster of Northeastern University is working on a nano-sized solution, developing a system that will sense problems with the implant and release drugs directly into the implant site. If an infection occurs, the sensor – made of carbon and titanium nanotubes – would detect the bacteria. The sensor would then relay this information through electrical signals to another part of the implant where antibiotics are stored, releasing them and stopping the infection before it gets out of control.
When something foreign – such as a piece of metal – is put into the body, it is often spotted by the immune system. The immune system launches an attack, causing the joint to get inflamed – red, swollen and sore. Webster’s design would also fight inflammation by detecting the presence of active immune cells and calming them down with drugs. Similarly, it could promote bone formation which is so critical to implant stability.