Biomerics of Salt Lake City will manufacture and distribute its patented Elast-Eon and ECSil materials and supply the polymer requirements of AorTech's current licensees.
It follows AorTech's exit from manufacturing and its adoption of a new strategy to "exploit the value of the company's IP, patents and knowhow without incurring the further substantial expenditure required to maintain and develop manufacturing facilities, product development expertise and sales and marketing resources".
Chairman Bill Brown, the former Edinburgh-based fund manager, said: "This is the most important deal AorTech has done."
He said AorTech's size and scale had made it impossible to get its material into major medical device companies, who were taking it "despite AorTech".
The company was rescued when emergency bondholders earned a 100% return and a 15% stake in the company for enabling AorTech to defend itself in US litigation last year.
Mr Brown said: "It is now a business that if everything goes to plan will take the material into new areas....we have got the potential to make more margin from any sales without having any cost, and are close to being a pure IP company." He said the heart valve project had potential "at some point - it has been one piece at a time".
Frank Maguire, chief executive, said: "This relationship with Biomerics provides for large volume manufacturing economies of scale.... a deep pool of talented application engineering resources facilitating new business development, and access to new customers and markets for AorTech polymers."
Aortech shares, which had climbed to 370p in February 2012 before crashing to 55p in October, rose 4p to 81.5p, valuing AorTech at just under £4m.