Pitcher Plant Inspires Revolutionary Coating for Medical Devices

A type of carnivorous plant, called the pitcher plant, may soon be saving more lives than it takes. The unusual insect trap has inspired the creation of a new coating for medical devices that could potentially prevent deadly clotting and infections in vulnerable patients.

The pitcher plant is an absolute nightmare for insects. They get drawn into the plant's deep throat with the promise of sweet-smelling nectar at its base. But when the insect has had its fill and decides to leave, it quickly learns that the sides of the throat are too slippery to climb out of. Eventually the insect succumbs to exhaustion, and is slowly digested by the horrific plant's juices.

That same slippery surface has been synthesized and repurposed into a new surface technology aptly named SLIPS (Slippery Liquid-Infused Porous Surfaces).

Now, according to a study recently published in the journal Nature Biotechnology a team of researchers have adapted SLIPS to coats the surfaces of tricky medical implants prone to encouraging blood clots or infection.

"Traditional SLIPS uses porous, textured surface substrates to immobilize the liquid layer whereas medical surfaces are mostly flat and smooth - so we further adapted our approach by capitalizing on the natural roughness of chemically modified surfaces of medical devices," co-author Joanna Aizenberg explained in a statement.

Essentially, the researchers roughed-up the surfaces of medical devices just so they could apply the coating, adding a liquid layer that provides a barrier to everything from blood to crude oil.

"Devising a way to prevent blood clotting without using anticoagulants is one of the holy grails in medicine," added senior author Don Ingber of Harvard's Wyss Institute for Biologically Inspired Engineering. Blood thinners can often have lethal side-effects, such as excessive bleeding.

The researchers called their coating strategy Tethered-Liquid Perfluorocarbon surface, or TLP for short, and found that it was even effective at preventing infection. When bacteria called Pseudomonas aeruginosa were grown in TLP-coated medical tubing for more than six weeks, less than one in a billion bacteria were able to adhere, lowering the chances of infection.

"We were wonderfully surprised by how well the TLP coating worked," added co-author Anna Waterhouse. "Usually the blood will start to clot within an hour in the extracorporeal circuit [of an implanted device], so our experiments really demonstrate the clinical relevance of this new coating."

The researchers now hope to test applications of the TLP strategy in more complex systems such as dialysis machines.