Rational design of AIEgens through π-bridge engineering for dual-modal photodynamic and photothermal therapy

A series of aggregation-induced emission luminogens (AIEgens) with donor-π-acceptor (D-π-A) architecture were rationally designed and synthesized through π-bridge engineering for dual-modal photodynamic and photothermal therapy. The AIEgens (TPT, TFT, and TTT) were constructed using methoxy-substituted tetraphenylene as the electron donor and tricyanofuran as the electron acceptor, connected via different π-bridges (phenyl, furan, or thiophene). These compounds exhibited red-shifted absorption (460-545 nm) and emission (712-720 nm) with remarkable aggregation-induced emission characteristics. Among them, TTT demonstrated superior photophysical properties and was successfully encapsulated into amphiphilic calixarene-based nanoparticles (T@Q NPs) with uniform morphology. The T@Q NPs showed efficient reactive oxygen species generation and photothermal conversion (η = 6.98 %), enabling effective tumor cell ablation through combined photodynamic and photothermal therapy. In vivo studies revealed that T@Q NPs achieved 70 % tumor growth inhibition in 4T1 tumor-bearing mice without obvious systemic toxicity. This work presents an effective strategy for designing AIEgens-based phototherapeutic agents through π-bridge engineering, offering promising candidates for clinical translation in tumor phototherapy.