His work has characterized reactions of oxidizing species with biological targets, the role of mitochondrial dysfunction is the alterations of cellular redox homeostasis and the impact of these biochemical processes in disease states.

This work has also contributed to understanding the redox biology of host cell interactions with intracellular pathogens and the impact in the control of infectious diseases.

His seminal paper related to the biochemical actions of peroxynitrite, a potent oxidant and nucleophile formed secondary to the diffusion-controlled reaction of nitric oxide with superoxide radicals together with Joe S. Beckman, Kent Bush and Bruce A. Freeman in 1991 has been selected as a JBC Classics due to its influence in the field.

Radi started studies at Universidad de la República in 1981 and became an MD (general medicine) in 1988 and PhD (biochemistry) in 1991.

In April 2020, Radi was appointed a member of the GACH, an advisory committee created by President Luis Lacalle Pou to define methods and studies to advise the government regarding the COVID-19 pandemic in Uruguay.