The SEM image on the left shows a commonly used Teflon surface implanted into mice that were infected with S. aureus. The unmodified device surface attracted the infectious bacteria (green). Red blood cells (red), immune cells (blue), and extracellular matrix material (yellow) are also shown to deposit on the surface. The SEM image on the right (colored purple) is the same Teflon surface treated with SLIPS within the infected mice. It shows no adhesion of cells or deposition of extracellular matrix material. (Credit: Wyss Institute at Harvard University)

A team of researchers has created self-healing slippery surface coatings with medical-grade Teflon materials and liquids that prevent biofilm formation on medical implants while preserving normal innate immune responses against pathogenic bacteria.

The technology is based on the concept of ‘slippery liquid-infused porous surfaces’ (SLIPS) developed by Joanna Aizenberg, Ph.D., a Wyss Institute core faculty member at Harvard University. They applied the SLIPS concept medical-grade Teflon to demonstrate its potential in implanted devices that are prone to bacterial fouling and infection. The team searched for the Teflon material that would work best with a selection of compatible lubricants to provide a long-lived repellent surface against a common device-associated bacterial strain. They chose ‘expanded polytetrafluoroethylene’ (ePTFE), which tested well with lubricants with proven acceptable safety profiles.

SLIPS coatings one day could obviate the widespread use of antibiotics, minimize the development of antibiotic resistant microorganisms, and enhance the capacity of temporary or permanent artificial devices to resist infection. Previous medical SLIPS applications include coatings that can repel bacteria and blood from small medical implants, tools, and surgical instruments that are made of steel.