These glass slides were dipped in blood to demonstrate the effectiveness of the TLP coating. While blood sticks to the untreated slide on the left, the TLP-treated slide on the right emerges entirely clear. (Credit: Harvard’s Wyss Institute)
As Don Ingber, M.D., Ph.D., Founding Director of Harvard’s Wyss Institute stated, “Devising a way to prevent blood clotting without using anticoagulants is one of the holy grails in medicine.” Even devices that have been properly analyzed and engineered to serve their purpose can run into problems once implanted into the body. Cardiac implants like mechanical heart valves and other medical devices come into contact with flowing blood. This can cause a multitude of problems such as blood clotting and bacterial infection.
To solve this problem, researchers at Wyss took already FDA approved materials and combined them to form a coating that repels both blood and bacteria. Originally, the idea for this coating came from Professor Amy Smith Berylson and her Slippery Liquid-Infused Porous Surfaces (SLIPS) system, a concept inspired by the carnivorous pitcher plant. The coating is created in a two-step surface-coating process. Coined Tethered-Liquid Perfluorocarbon (TLP), the process is performed by adding a monolayer of perfluorocarbon and then a layer of liquid perfluorocarbon.
This material has already been tested in vivo where the team implanted tubing and catheters with this coating into blood vessels of pigs. The results showed no blood clots for at least eight hours. Furthermore, when the bacteria Pseudomonas aeruginosa was cultured on a coated medical tube, only one in a billion bacteria adhered to the tube. The scientists even demonstrated that the mighty gecko could not stick to surfaces coated with TLP.
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