Multifunctional radiolabeled nanoparticles: strategies and novel classification of radiopharmaceuticals for cancer treatment

In this review, we emphasize the efforts on the development of radiolabeled nanoparticles (NPs) for cancer treatment, i.e. theranostic tools based on nanotechnology and nuclear medicine. Currently, radionuclide therapy remains to be an important treatment option. The ionizing radiation from radionuclides (not provided by drugs) can kill cells or inhibit the growth in the periphery and the inaccessible center of cancerous lesions. Sites of damage comprise all cellular levels, especially DNA in the nucleus of cells. In addition, recent developments in nanotechnology have made it possible to conjugate NPs to biological moieties for targeted therapy. This enables the more specific radiation dose delivery, preventing damage to healthy tissues. Before the introduction of these NPs-based radionuclide therapies in clinical practice, it is necessary perform investigations to demonstrate dosage-accurate radiation delivery, biocompatibility, pharmacokinetic/pharmacodynamic parameters and risk/benefit evaluations. Because of these issues, a transition to clinical trials is difficult. The properties of NPs make it possible to build theranostic devices with targeting and regulatory mechanisms offered by biological effectors against cancer.