Dr. Paolo Macchiarini is world famous for his revolutionary stem cell-infused windpipe transplants. There's just one problem: His patients keep dying.

The work of Paolo Macchiarini, who set out to revolutionize regenerative medicine in 2011 by implanting plastic windpipes in patients desperate for a cure. But Macchiarini lied about his research and three of those he treated died, while a fourth later had their artificial windpipe removed. A Swedish appeals court convicted Macchiarini on Wednesday and sentenced him to two-and-a-half years in prison. He has denied any criminal wrongdoing. According to Associated Press, the Svea Court of Appeal ruled that two of the three patients who died did not require emergency intervention, while the procedure on the third was not justified. "Macchiarini realized the risk of the interventions would cause the patients bodily harm and suffering and that he, even though he has had a hope that the method would work, has been indifferent to the risks," the court is reported to have said.