Gold Nanostars-AIE Theranostic Nanodots with Enhanced Fluorescence and Photosensitization Towards Effective Image-Guided Photodynamic Therapy

Abstract

Dual-functional aggregation-induced photosensitizers (AIE-PSs) with singlet oxygen generation (SOG) ability and bright fluorescence in aggregated state have received much attention in image-guided photodynamic therapy (PDT). However, designing an AIE-PS with both high SOG and intense fluorescence via molecular design is still challenging. In this work, we report a new nanohybrid consisting of gold nanostar (AuNS) and AIE-PS dots with enhanced fluorescence and photosensitization for theranostic applications. The spectral overlap between the extinction of AuNS and fluorescence emission of AIE-PS dots (665 nm) is carefully selected using five different AuNSs with distinct localized surface plasmon (LSPR) peaks. Results show that all the AuNSs can enhance the 1O2 production of AIE-PS dots, among which the AuNS with LSPR peak at 585 nm exhibited the highest 1O2 enhancement factor of 15-fold with increased fluorescence brightness. To the best of our knowledge, this is the highest enhancement factor reported for the metal-enhanced singlet oxygen generation systems. The Au585@AIE-PS nanodots were applied for simultaneous fluorescence imaging and photodynamic ablation of HeLa cancer cells with strongly enhanced PDT efficiency in vitro. This study provides a better understanding of the metal-enhanced AIE-PS nanohybrid systems, opening up new avenue towards advanced image-guided PDT with greatly improved efficacy.

Singlet Oxygen Photosensitization Using Graphene-Based Structures and Immobilized Dyes: A Review

“…A high 1 O 2 enhancement was observed for homogeneous rose bengal in the presence of SiO 2 @AuBPs using continuous photooxygenation of methionine. Gold nanostars were also reported to enhance 1 O 2 production of aggregation-induced photosensitizers by 15-fold . The effects of incoherent coupling and near and far-fields is proved to be important on the enhanced 1 O 2 generation. ,, …”

“…Gold nanostars were also reported to enhance 1 O 2 production of aggregation-induced photosensitizers by 15-fold. 304 The effects of incoherent coupling and near and far-fields is proved to be important on the enhanced 1 O 2 generation. 297,305,306 In spite of plasmonic nanoparticles, magnetic nanoparticles have be proven to decrease the 1 O 2 enhancement because they could compete for light absorption with photosensitizers.…”

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

“…Based on this, Tan et al further developed Au nanostar@AIE nanodots to achieve both excellent MEF and ME-SOG efficiencies simultaneously, which is important for the application of effective FLI-guided PDT. 252 As depicted in Fig. 14b, ultrasmall and negatively charged AIE-PS nanodots were formed by encapsulating AIE PSs within DSPE-mPEG 2000 , which were then adsorbed onto positively charged PEI-capped Au nanostars (Au NSs) via electrostatic interaction.…”

Multiple Light-Activated Photodynamic Therapy of Tetraphenylethylene Derivative with AIE Characteristics for Hepatocellular Carcinoma via Dual-Organelles Targeting

“…Recently, some AIEgens were designed to exhibit excellent photosensitization and ROS generation ability, which broadens their potential applications in PDT of cancer. The unique features of AIEgens provide new opportunities for the facile design of PS with special function, high accuracy, and efficacy for image-guided PDT [30][31][32][33].…”