Rational Molecular Engineering of Organic Semiconducting Nanoplatforms for Advancing NIR-Ⅱ Fluorescence Theranostics

摘要

Second near-infrared window (NIR-Ⅱ, 1000?1700 nm) fluorescence imaging(FI) in phototheranostics benefits from deep tissue penetration, negligiblebody spontaneous fluorescence, exceptional spatiotemporal resolution,and diversified imaging agents. Inorganic and metal nanomaterials withNIR-Ⅱ emission are widely explored for NIR-Ⅱ FI, however, the concernabout their intrinsic long-term toxicity hampers further clinic applications.By contrast, whole organic NIR-Ⅱ FI agents, in particular, organic semiconductingmolecules derived from large π-conjugated molecular architecturesand biologically amicable ingredients, owning inert photophysical potencies,tunable optical properties, and favorable biocompatibility, have thepotential to be degraded and excreted from the body in molecular level.In this review, the development of NIR-Ⅱ fluorescence-emitting organicsemiconducting nanoplatforms, with a focus on their theranostic applicationsin biomedicine is discussed. The recent advances in the moleculardesign of semiconducting NIR-Ⅱ emitting agents for improving the propertiesof NIR-Ⅱ photonics (e.g., emission intensity, quantum yield, emissionwavelength, and activatable emission) and optimizing disease phototheranostics(the synergistic combination of NIR-Ⅱ FI-based diagnosis andphoto-related therapeutic methods) are highlighted. Finally, the challengesand perspectives to building high-powered new-generation organic semiconductingnanoplatforms for NIR-Ⅱ phototheranostics of a variety ofdiseases are discussed.