Organic Spherical NucleicAcids for the Transport ofaNIR-II-Emitting Dye Across the Blood-Brain Barrier

DNA nanotechnology plays an increasingly important role in the biomedical field; however, its application in the design of organic nanomaterials is underexplored. Herein, we report the use of DNA nanotechnology to transport a NIR-II-emitting nanofluorophore across the blood-brain barrier (BBB), facilitating non-invasive imaging of brain tumors Specifically, the DNA block copolymer, PS-b-DNA, is synthesized through a solid-phase click reaction. We demonstrate that its s elf-assembled structure shows exceptional cluster effects, among which BBB-crossing is the most notable. Therefore, PS-b-DNA is utilized as an amphiphilic matrix to fabricate a NIR-¡I nanofluorephore, which is applied in in vivo bioimaging. Accordingly, the NIR-1 I fluorescence signal of the DNA-based nanofluorophore localized at a glioblastoma is 3.8-fold higher than the NIR-H fluorescence signal of the PEG-based counterpart The notably increased imaging resolution will significantly benefit the further diagnosis and therapy of brain tumors.