The founder and chief executive officer of a California-based company that marketed stem cell-based products linked to multiple hospitalizations has pleaded guilty to a felony violation of the Federal Food, Drug and Cosmetic Act, the Justice Department announced. John Warrington Kosolcharoen, 53, most recently of Rancho Santa Margarita, pleaded guilty to one count of introducing an unapproved new drug into interstate commerce with the intent to defraud and mislead. Kosolcharoen is currently in custody serving a sentence for a separate, unconnected conviction. According to court documents, beginning in 2016, Kosolcharoen created two companies, the Irvine-based Liveyon LLC and the San Diego-based Genetech Inc., to manufacture and distribute injectable stem cell products made from human umbilical cord blood. Liveyon marketed the products under different brand names, including “ReGen.” In pleading guilty, Kosolcharoen admitted that he and others misrepresented ReGen as suitable for the treatment of a variety of conditions, such as lung and heart diseases, autoimmune disorders, Alzheimer’s disease, Parkinson’s disease and others. Liveyon marketed the products throughout the United States until about April 2019 using advertising materials that contained multiple false and misleading statements about their purported safety and effectiveness.