A “protective umbrella” nanoplatform for loading ICG and multi-modal imaging-guided phototherapy

ICG as a photosensitizer or imaging probe tends to form severe aggregation and lack of the target ability, thus leading to low phototherapy efficiency or fluorescence self-quenching in aqueous environments. In order to overcome the difficulty, β-CD was utilized as an umbrella to load ICG and keep ICG in a separated and monomeric state, thus improving the phototherapy efficiency on tumor and imaging abilities. Then, HA, a naturally occurring polysaccharide, formed a shell outside the surface of TiO2:Yb,Ho,F-β-CD via electrostatic attraction, which could not only prevent ICG from the interference of aqueous environments but also serve as a target to recognize CD44 receptor on tumor cell, finally promoting the accumulation of ICG at tumor.194