Strategic Objectives of Nanotechnology-Driven Repurposing in Radiopharmacy—Implications for Radiopharmaceutical Repurposing (Beyond Oncology)

Abstract

The integration of nanotechnology into drug repurposing strategies is redefining the developmentlandscape for diagnostic, therapeutic, and theranostic agents. In radiopharmacy,nanoplatforms are increasingly being explored to enhance or extend the use of existingradiopharmaceuticals, complementing earlier applications in other biomedical fields.Many of these nanoplatforms evolve into multifunctional systems by incorporating additionalimaging modalities (e.g., MRI, fluorescence) or non-radioactive therapies (e.g.,photodynamic therapy, chemotherapy). These hybrid constructs often emerge from thereformulation, repositioning, or revival of previously approved or abandoned compounds,generating entities with novel pharmacological, pharmacokinetic, and biodistributionprofiles. However, their translational potential faces significant regulatory hurdles. Existingframeworks—typically designed for single-modality drugs or devices—struggle toaccommodate the combined complexity of nanoengineering, radioactive components, andintegrated functionalities. This review examines how these systems challenge current normsin classification, safety assessment, preclinical modeling, and regulatory coordination. Italso addresses emerging concerns around digital adjuncts such as AI-assisted dosimetry andsoftware-based therapy planning. Finally, the article outlines international initiatives aimed atclosing regulatory gaps and provides future directions for building harmonized, risk-adaptedframeworks that support innovation while ensuring safety and efficacy.