A coat of diamonds could make implants more biocompatible

Diamonds are forever but our bodies can barely last a century. We break down, tear up, and eventually decay. Along our way from dust to dust, surgeons try to help keep us intact as best they can, often with implants to keep our physical selves together. But our bodies are fastidious things and have to be tricked into letting foreign objects stay, which can complicate biomedical implants, typically made of titanium and occasionally rejected by the body.

Now researchers from the Royal Melbourne Institute of Technology (RMIT) University may have devised a way to better coerce the body to accept implants, with a strategy that includes 3D-printing diamond-coated devices. It may sound like a luxury afforded only to the materialistic few but it could actually make implants more accessible and biocompatible.

“3D printing of metals for medical implants is quickly becoming commonplace,” Kate Fox, the RMIT biomedical engineer who led the research, told Digital Trends. “Everyone wants to have an implant that fits their bodies. As a result, many researchers are designing complicated implants which can be 3D-printed specific to need. That is, if you want a hip implant, it can be made the same size and shape as your damaged hip. Titanium which is the most common material used for medical implants, as it is inert with the body. This means though that the cells inside the body and the bone won’t ever grow onto it. By adding a diamond coating, we now provide a carbon coating … which the cells can interact with, whilst keeping the personalized 3D-printed shape.”

3D printing has helped create things like complex art and yachts, but some of the most life-changing applications have been made in biotech, where the relatively cheap process makes implants and bionic limbs accessible to those who may not otherwise have them. The method proposed by Fox and her team would entail coating titanium implants with a film of diamonds to be more biocompatible.

“Carbon is 20 percent of the human body,” Fox said. “As such, diamond, which is also carbon, provides a material that the body will readily accept as its own. This means that the body will be less likely to try and remove it. We therefore believe that rejection will be reduced and post-surgical complications due to material compatibility will be ameliorated.”

The diamond that would cover an implant is not the kind that has to be mined. Fox and her colleagues propose synthetic diamonds, made from concentrated carbon called nanodiamonds, that have been chemically altered to form a film and coated onto a 3D-printed titanium part in a plasma microwave.

There is still plenty of work ahead before patients can expect to have diamond-coated implants. Fox and her team need to run pre-clinical and clinical trials, but hope this technology will make it to the market in the next five years.

A paper detailing the research was published last month in the journal ACS Applied Materials and Interfaces.