Self-assembled nanostructured photosensitizer with aggregation-induced emission for enhanced photodynamic anticancer therapy

Three nanostructured photosensitizers with aggregation-induced emission (AIE) characteristics based on 2,3-bis(4 '-(diphenylamino)-[1,1 '-biphenyl]-4-yl) fumaronitrile (BDBF) were prepared for image-guided photodynamic therapy (PDT). BDBF was encapsulated with Pluronic F-127 (F127) to form usual spherical nanoparticles (F127@BDBF NPs) with a red fluorescence emission and 9.8% fluorescence quantum yield (FQY). Moreover, BDBF self-assembled into nanorods (BDBF NRs) in water. Compared with F127@BDBF NPs, BDBF NRs exhibited stronger orange fluorescence with a higher FQY of 23.3% and similar singlet oxygen (O-1(2)) generation capability. BDBF NRs were further modified with F127 to form BDBF@F127 NRs with the same O-1(2) generation ability as BDBF NRs. The three nanostructures exhibited a higher O-1(2) production capacity than BDBF molecule in dissolved state and favorable stability in an aqueous solution as well as under physiological condition. In vitro photocytotoxicity experiments indicated that the three nanostructures inhibited tumor cell proliferation effectively. Therefore, to construct eligible nanostructures with a high FQY and O-1(2) generation ability, simple self-assembly can serve as a valuable method to prepare photosensitizers with enhanced PDT.