Rose-Bengal-Tethered Polymer Encapsulant for Carbon-Nanohorn Conjugates: Theranostic Potential for Multimodal Imaging and Phototherapy.

This paper presents the molecular design of a rose-bengal-containing functional polymer for the encapsulation of carbon nanohorns (CNHs). The polymer chain consists of hydrophilic monomers and dangling oxirane moieties that tether the rose bengal units. It exhibits high biocompatibility with CNHs and excellent coating ability, resulting in a carbon-based nanoconjugate with a core-shell nanostructure. The dahlia-like CNH core generates photoacoustic signals and heat in response to near-infrared light irradiation, while the polymer shell produces fluorescence signals and reactive oxygen species under visible light irradiation. The multimodal imaging properties of the proposed nanoconjugate are investigated under simulated endoscopic and in vivo imaging conditions and in a photoacoustic microscopy system. In addition, the significant photothermal and photodynamic effects are evaluated in vitro, confirming its potential as a theranostic agent. This design concept can be advanced further by tethering prodrugs, targeting moieties, or enzymes to the backbone, paving the way for the development of a versatile theranostic platform.