For a glimpse at vinyl's bleeding edge, look no further than the upcoming medical compounds from Teknor Apex (www.teknorapex.com). The company last month announced development plans for polyvinyl chloride (PVC) compounds that prevent blood clot formation in medical devices.
These compounds will be based on an anti-clotting copolymer from VESTOLIT GmBH & Co. KG, a leading European PVC producer (www.vestolit.com, Marl, Germany). According to Peter Galland, Teknor's medical manager, the VESTOLIT copolymer incorporates anti-clotting, Heparin-like molecules into a PVC polymer backbone. Teknor will pair this copolymer with its proven medical PVC compounds.
The resulting bioactive materials will address all sorts of extruded medical tubing—including catheters, and "extracorporeal" circuits that route a patient's blood through medical equipment. Galland adds that the anti-clotting compounds will also be suitable for injection molding—for tubing connectors and related parts. Galland says the physical and mechanical properties of the anti-clotting grades won't deviate from those of standard medical vinyl compounds.
Teknor's new compounds won't be the only anti-clotting—or "anti-thrombogenic"—materials technology on the market. Anti-thrombogenic coatings for PVC, which can be applied to the blood-contact surfaces of medical devices, have been in use for years. But Galland predicts that materials with inherent anti-clotting capabilities will have a leg up in the cost department. "We expect they'll cost at least an order of magnitude less than coated compounds," he says. Some of that cost advantage will spring from how the new materials are fabricated into medical devices. Galland explains that the anti-clotting polymer will be most cost-effective in co-extruded structures—that is, as a thin layer over standard vinyl. "There's no need to have 100% thickness of the bioactive material," he says.
Device manufacturers interested in the new material will soon be able to sample it, Galland says. But it will take time before the new materials can go into production. "It might be another 18 to 36 months," he says.