Nanostructured organic photosensitizer aggregates in disease phototheranostics

[Display omitted] •Focusing on disease phototheranostic applications of nanostructured organic photosensitizer aggregates (NOPSAs).•Highlighting diverse NOPSAs including polymer-loading NOPSAs, polymeric NOPSAs, and small molecule-assembled NOPSAs.•Discussing energy dissipation pathways of NOPSAs, termed radiative emission, vibrational relaxation, and intersystem crossing.•Addressing aggregation-photophysical property relationships and their treatment, imaging and sensing strategies in detail. Aggregate science provides promising opportunities for the discovery of novel disease phototheranostics. Under the guidance of aggregology and the Jablonski energy level diagram, photosensitizer aggregates with tunable photophysical properties can consequently result in tailorable diagnosis and treatment modalities. This review summarizes recent advances in the formation of nanostructured organic photosensitizer aggregates, their photophysical processes (e.g., radiative emission, vibrational relaxation, and intersystem crossing), and particularly, their applications in disease phototheranostics such as fluorescence imaging and sensing, photothermal therapy, photoacoustic imaging, and photodynamic therapy. It is expected that this comprehensive summary will provide guidance for the construction of nanostructured organic photosensitizer aggregates, for establishment of aggregation-photophysical property relationships and the development of novel disease phototheranostic nanomedicines.