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

Abstract

Three nanostructured photosensitizers with aggregation-induced emission (AIE) characteristics based on 2,3-bis(4ʹ-(diphenylamino)-[1,1ʹ-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 (1 O 2) generation capability. BDBF NRs were further modified with F127 to form BDBF@F127 NRs with the same 1 O 2 generation ability as BDBF NRs. The three nanostructures exhibited a higher 1 O 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 1 O 2 generation ability, simple self-assembly can serve as a valuable method to prepare photosensitizers with enhanced PDT.

The fast-growing field of photo-driven theranostics based on aggregation-induced emission

“…In pursuit of higher possibility and convenience for in vivo application, hydrophobic AIE PSs usually need to be encapsulated within nanocarriers to form well-dispersed NPs with good water solubility and biocompatibility. 48,49,51,[136][137][138][139][140][141][142][143][144][145][146][147][148][149][150] More importantly, enhanced fluorescence intensity, promoted ROS generation and EPR effect-mediated tumor accumulation can be readily realized simultaneously after nanofabrication. For example, a hydrophobic AIE PS named TBTC8 with emission over 800 nm was designed and subsequently loaded into DSPE-PEG 2000 formed NPs for the PDT of 4T1 tumor-bearing mice by Liu and coworkers.…”

Photodynamic Therapy and Hyperthermia in Combination Treatment—Neglected Forces in the Fight against Cancer

“…In the context of combination therapy, chemotherapeutic substances may accumulate more intensively in the neoplastic tissue due to a “therapeutic window” [ 21 ]. This method is selective and the issue of combining photosensitizers with nanostructures is increasingly discussed [ 239 , 240 ]. An alternative “therapeutic window” mechanism involves creating perfusion/oxygen enhancement in neoplastic tissue.…”

Mitochondria-Specific Aggregation-Induced Emission Luminogens for Selective Photodynamic Killing of Fungi and Efficacious Treatment of Keratitis

“…23,24 Oppositely, AIE PSs exhibit enhanced fluorescence and efficient 1 O 2 generation upon aggregation, making them excellent candidates for image-guided PDT. 18,25,26 It has been reported that AIEgens with cationic charge and suitable hydrophobicity tend to target the mitochondria of eukaryotic cells. 24,25,27−30 For example, cationic AIE PSs have been reported to distinguish cancer and normal cells based on the difference in plasma and mitochondrial membrane potential, achieving selective light-up and killing of cancer cells by PDT.…”