Whenever physicians implant a “foreign” device in the body, as orthopaedists often do, the implant is up against two crucial challenges: blood clots and bacteria. Solving both of those challenges took a big step forward with the recent publication in Nature Biotechnology of results with a new device-surface coating that thwarts blood clotting and keeps certain bacteria from sticking to it through glycocalyx formation. The repellant coating, called tethered-liquid perfluorocarbon, or TLP, is a modified version of the super-slippery stuff that the carnivorous pitcher plant uses to catch insects.
Harvard researchers tested the coating, the two constituents of which are already FDA-approved, in vitro on 20 different medical surfaces, including glass and metal, where it suppressed platelet adhesion and activation under simulated blood flow. They also tested it in vivo with catheters implanted into the large veins of pigs, where it prevented blood clotting for eight hours without the use of anticoagulants. In another in vitro experiment during which TLP-coated medical tubing was exposed to Pseudomonas aeruginosa for six weeks, only one in a billion of the bacteria were able to adhere.
It’s too early to say with certainty if and when TLP coatings might be ready for use on orthopaedic implants, but the approach raises hopes that a powerful new preventer of two major complications associated with orthopaedic device implantation is feasible in the near future.