Magnetic nanoparticles in theranostic applications

Nanomedicine research recently started exploring the combination of therapy and diagnostics, so-called theranostics, as an approach to offer a more flexible, personal, and precise care with improved patient outcomes. As magnetic nanoparticles show great potential in a variety of diagnostic and therapeutic applications, they are prime candidates to be used in a theranostic platform to realize this vision. This Perspective gives an overview of state-of-the-art magnetic imaging techniques and theranostic applications based on magnetic nanoparticles and discusses their opportunities and associated challenges. In order to address these challenges and to exploit these opportunities to the fullest, we discuss three promising research directions. The first considers the use of novel magnetic field sequences to utilize the rich magnetic dynamics of the particles, allowing a more accurate diagnosis and boosting the performance of many nanoparticle-based applications. Second, we introduce the innovative concept of smart theranostics based on feedback mechanisms between the particle applications and their supporting imaging procedure to enhance the performance of both and to allow real-time monitoring of treatment efficiency. Finally, we show the twofold advantage of applying data-driven models to enhance therapy and diagnostics on the one hand and for handling the platform’s large amount of data and associated decision support algorithms on the other. The latter research track is extended to include hybrid models in which physics-based and data-driven models are combined to overcome challenges of applications with limited data, making the data-driven part understandable, as well as in uncovering unknown nanoparticle dynamics. Contrasting other literature works, which mainly focus on developing magnetic nanoparticles with the right characteristics, we put forward advances in magnetic nanoparticle imaging techniques and applications to enable the use of a broader range of magnetic nanoparticles in theranostics. We seek to emphasize the importance of these building blocks as many research opportunities with a very high potential are still left open. Therefore, we encourage researchers to also take these aspects into account to advance theranostic applications of magnetic nanoparticles to real clinical environments.