ACell, Incorporated is a Columbia, Maryland-based biotechnology company. The company works in regenerative medicine, in which it owns several valuable extracellular matrix patents. ACell develops, manufactures and markets products for medical and veterinary applications. The company is founded by Alan R. Spievack, a former associate professor at Harvard Medical School and currently run by Patrick A. McBrayer. ACells use of porcine cellular structure, called MatriStem, as a scaffold for human tissue regeneration was named the "medical breakthrough of the year" by Esquire. The use of pig bladder ground up into "magical pixie dust" to regrow Spievaks brothers finger received considerable mainstream coverage. Ken Muneoka of Tulane University, who works with ACells scientific advisors on US-government funded investigations into regenerative medicine, said that the news should be viewed with caution because it was not a controlled study.