**Mattia Bartoli 1,2 , Pravin Jagdale <sup>3</sup> and Alberto Tagliaferro 1,2,\***


Received: 28 October 2020; Accepted: 18 November 2020; Published: 19 November 2020

**Abstract:** In this review, we reported the main achievements reached by using bismuth oxides and related materials for biological applications. We overviewed the complex chemical behavior of bismuth during the transformation of its compounds to oxide and bismuth oxide phase transitions. Afterward, we summarized the more relevant studies regrouped into three categories based on the use of bismuth species: (i) active drugs, (ii) diagnostic and (iii) theragnostic. We hope to provide a complete overview of the great potential of bismuth oxides in biological environments.

**Keywords:** bismuth oxide; nanoparticles; radiopacity; chemotherapy; theragnostic
