Recent progress of nanotechnology-based theranostic systems in cancer treatments.

Theranostics that integrates therapy and diagnosis in one system to achieve accurate cancer diagnosis and treatment has attracted tremendous interest, and has been recognized as a potential breakthrough in overcoming the challenges of conventional oncotherapy. Nanoparticles are ideal candidates as carriers for theranostic agents, which is attributed to their extraordinary physicochemical properties, including nanoscale sizes, functional properties, prolonged blood circulation, active or passive tumor targeting, specific cellular uptake, and in some cases, excellent optical properties that ideally meet the needs of phototherapy and imaging at the same time. Overall, with the development of nanotechnology, theranostics has become a reality, and is now in the transition stage of "bench to bedside." In this review, we summarize recent progress on nanotechnology-based theranostics, i.e., nanotheranostics, that has greatly assisted traditional therapies, and has provided therapeutic strategies emerging in recent decades, as well as "cocktail" theranostics mixing various treatment modalities.