He became an assistant to the French physician and professor Henry Galliard, dean of the Department of Bacteriology at the school.
In 1949, he returned to Vietnam and joined the Viet Minh resisting against French rule, becoming the lead lecturer in bacteriology in the Medical School at Chiêm Hóa.
During his time in the Viet Minh, he successfully researched a method to manufacture penicillin.
On April 1, 1967, he was killed in an American bombing in the Annamite Range while in Thừa Thiên–Huế Province while researching malaria.
He was awarded the Ho Chi Minh Prize for his contributions to medical research.