Plasmon-Enhanced Photodynamic Therapy for Gastric Cancer by Integrating Targeted Gold Nanorods and Photosensitizer

Abstract

Gold nanoparticles are widely used for biomedical purposes because of their unique optical, surface plasmon resonance properties, ease of surface functionalization, and high load capacity. Gold nanorods (AuNR), which are rod-shaped gold nanoparticles, have been used as an effective photodynamic treatment (PDT) carrier to boost singlet oxygen (SOG) generation through localized surface plasmon resonance (LSPR) effect and then improve PDT efficacy. However, the suitable spatial location should be established to enable photosensitizer to feel the LSPR enhancement. In this study, we utilized multifunctional PEG chain to adjust efficient distance to induce more photosensitizers to feel the enhanced LSPR effect of AuNR and used a novel gastric tumor angiogenesis marker to prevent the uncontrolled LSPR shift induced by the aggregation of AuNR, and then acquire plasmon-enhanced PDT. The synthesized nano-system of integrated photosensitizer and targeted AuNR could significantly enhance SOG generation and improve the apoptosis-inducing ability through activation of the mitochondria-mediated apoptotic pathway, and -shorten the induction time for apoptosis, thus acquire efficient plasmon-enhanced PDT. Comparing to the normal photosensitizer, half of the targeted photosensitizer produce same antitumor effect, which improves maximum tolerable dose. Generally, this novel targeted delivery system is a promising agent of plasmon-enhanced PDT for gastric cancer.