Fluorinated triphenylamine phthalocyanine @ silica-coated gold nanorods: A photoactivated lysosome escape and targeting mitochondria two-photon probe for imaging-guided photothermal synergistic photodynamic therapy in cancer cells

Abstract

The timely evasion of nanomedicines from lysosomes is essential to avert premature degradation under the acidic and hydrolytic conditions characteristic of these cellular compartments. However, the development of effective strategies has been hindered by the complexity of design material and the scarcity of practical methods. In this study, we have synthesized a novel nanoparticle, designated as TPA-BPAF-SiPc@AuNR@SiO2. This nanoparticle was prepared by encapsulating near-infrared fluorinated triphenylamine-substituted silicon phthalocyanines (TPA-BPAF-SiPc) within mesoporous silica-coated gold nanorods (AuNR@SiO2). TPA-BPAF-SiPc@AuNR@SiO2 functions as a dual-function two-photon probe, facilitating photoactivated lysosome escape and targeting mitochondria. The inherent aggregation-induced emission (AIE) two-photon fluorescence of TPA-BPAF-SiPc is notably bright when encapsulated in AuNR@SiO2 nanocarriers, a phenomenon not observed in polymer nanocarriers composed of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000) or in THF/water mixtures. Upon irradiation, this nanoparticle autonomously escapes from lysosomes and selectively targets mitochondria, a process can be visually monitored in real-time through the two-photon AIE fluorescence of TPA-BPAF-SiPc. Moreover, upon activation, TPA-BPAF-SiPc@AuNR@SiO2 produces a substantial quantity of reactive oxygen species (ROS) and induces hyperthermia effects, showcasing its potential for effective photodynamic therapy (PDT) in conjunction with synergistic hyperthermia. Flow cytometry data corroborate the induction of tumor cell death through both necrosis and apoptosis pathways by TPA-BPAF-SiPc@AuNR@SiO2. This study underscores the potential of TPA-BPAF-SiPc@AuNR@SiO2 as a multifunctional probe capable of enabling lysosome escape, mitochondria targeting, and two-photon fluorescence imaging-guided photothermal synergistic photodynamic therapy, specifically tailored for the treatment of breast cancer.