A covalent organic framework-based multifunctional therapeutic platform for enhanced photodynamic therapy via catalytic cascade reactions

• Published in: Science China materials Vol. 64; no. 2; pp. 488 - 497
• Main Authors: Cai, Lihan, Hu, Chunling, Liu, Sainan, Zhou, Ying, Pang, Maolin, Lin, Jun
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.02.2021; Springer Nature B.V
• Subjects: Anticancer properties; Biocompatibility; Cancer; Cascade chemical reactions; Chemistry and Materials Science; Chemistry/Food Science; Glutathione; Gold; Hyaluronic acid; Hydrogen peroxide; Magnetic resonance imaging; Manganese dioxide; Materials Science; Nanoparticles; Photodynamic therapy; Substrates; tumor microenvironment; cascade reaction; enhanced photodynamic therapy; covalent organic framework
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-020-1428-0

Utilizing the unique tumor microenvironment (TME) to conduct chemical reactions for cancer treatment becomes a hot topic recently. Nevertheless, single chemical reaction in TME is often restricted by scanty reaction substrates and slow reaction rate. Meanwhile, the toxic substances produced by the reactions are usually not enough to kill cancer cells. Herein, using covalent organic frameworks (COFs) as the template, Au nanoparticles (Au NPs) were subsequently grown on the surface of the COF, then a thin layer of manganese dioxide (MnO 2 ) was coated over the material, and finally hyaluronic acid (HA) was introduced to improve the biocompatibility. The resultant product, named COF-Au-MnO 2 , was involved in several processes to form cascade reactions in the TME. Specifically, under hypoxic conditions, COF-Au-MnO 2 could react with intratumoral H 2 O 2 to produce O 2 to enhance the type II photodynamic therapy (PDT), and Au NPs could decompose glucose to promote starving-like therapy. Besides, starving-like therapy can also produce H 2 O 2 to increase O 2 production. Simultaneously, MnO 2 can consume glutathione (GSH) to enhance the antitumor efficacy, and the released Mn 2+ could be used for T 1 -weighted magnetic resonance imaging (MRI). Both in vitro and in vivo experiments had proven excellent cancer cell killing effect and antitumor efficacy of COF-Au-MnO 2 via such a cycle-like process.