Fiber Optic-Mediated Type I Photodynamic Therapy of Brain Glioblastoma Based on an Aggregation-Induced Emission Photosensitizer.

in Advanced materials (Deerfield Beach, Fla.) by Wenguang Zhang, Miaomiao Kang, Xue Li, Yinzhen Pan, Zhuorong Li, Yibin Zhang, Changrui Liao, Gaixia Xu, Zhijun Zhang, Ben Zhong Tang, Zhourui Xu, Dong Wang

TLDR

  • The study develops a new way to treat a deadly brain tumor called Glioblastoma (GBM) using a modified optical fiber and a special kind of light called photodynamic therapy (PDT). The study shows that this new approach is more effective than the current standard-of-care and could be a promising treatment option for GBM.

Abstract

Glioblastoma (GBM) is one of the most lethal human malignancies. The current standard-of-care is highly invasive with strong toxic side effects, leading to poor prognosis and high mortality. As a safe and effective clinical approach, photodynamic therapy (PDT) has emerged as a suitable option for GBM. Nevertheless, its implementation is significantly impeded by the limits of light penetration depth and the firm reliance on oxygen. To overcome these challenges, herein, a promising strategy that harnesses a modified optical fiber and less oxygen-dependent Type I aggregation-induced emission (AIE) photosensitizer (PS) is developed for the first time to realize in vivo GBM treatments. The proposed AIE PS, namely TTTMN, characterized by a highly twisted molecular architecture and a bulky spacer, exhibits enhanced near-infrared emission and strong production of hydroxyl and superoxide radicals at the aggregated state, thus affording efficient fluorescence imaging-guided PDT once formulated into nanoparticles. The inhibition of orthotopic and subcutaneous GBM xenografts provides compelling evidence of the treatment efficacy of Type I PDT irradiated through a tumor-inserted optical fiber. These findings highlight the substantially improved therapeutic outcomes achieved through fiber optic-mediated Type I PDT, positioning it as a promising therapeutic modality for GBM.

Overview

  • The study focuses on developing a promising strategy for photodynamic therapy (PDT) of Glioblastoma (GBM) using a modified optical fiber and less oxygen-dependent Type I aggregation-induced emission (AIE) photosensitizer (PS).
  • The methodology involves the development of a new AIE PS, TTTMN, with a highly twisted molecular architecture and a bulky spacer, which exhibits enhanced near-infrared emission and strong production of hydroxyl and superoxide radicals at the aggregated state. The PS is formulated into nanoparticles for fluorescence imaging-guided PDT. The study uses orthotopic and subcutaneous GBM xenografts to evaluate the treatment efficacy of Type I PDT irradiated through a tumor-inserted optical fiber.

Comparative Analysis & Findings

  • The study compares the outcomes observed under different experimental conditions, specifically the use of the new AIE PS, TTTMN, versus the current standard-of-care for GBM. The results show that Type I PDT irradiated through the modified optical fiber using TTTMN nanoparticles significantly improves therapeutic outcomes compared to the current standard-of-care. The study identifies the enhanced near-infrared emission and strong production of hydroxyl and superoxide radicals at the aggregated state of TTTMN as key factors contributing to the improved therapeutic outcomes. The findings support the potential of fiber optic-mediated Type I PDT as a promising therapeutic modality for GBM.

Implications and Future Directions

  • The study's findings highlight the potential of fiber optic-mediated Type I PDT as a promising therapeutic modality for GBM. The limitations of light penetration depth and the reliance on oxygen are addressed through the use of a modified optical fiber and less oxygen-dependent AIE PS. The study identifies several future research directions, including the optimization of the AIE PS for improved therapeutic outcomes, the exploration of different optical fiber designs for enhanced light penetration depth, and the evaluation of the safety and efficacy of fiber optic-mediated Type I PDT in human clinical trials.