Two-Dimensional Fully Conjugated Polymeric Photosensitizers for Advanced Photodynamic Therapy

Abstract

Photodynamic therapy (PDT) is attractive for treatment of various cancers, with a high selectivity, minimal long-term effect, and excellent cosmetic appeal. Well water-dispersive photosensitizers with strong optical absorption within the tissue transparency window (700−1000 nm) are needed for efficient PDT. However, clinically used PDT agents based on oligomeric porphyrin units (e.g., protoporphyrin IX) are effective at 532 nm irradiation only. Herein, we synthesized a two-dimensional covalent organic polymer (COP) containing fully conjugated multiple porphyrin macrocycles with sulfonic acid side groups. The resultant COP-P-SO 3 H is well water-dispersive, showing strong optical absorption within the desired therapeutic window and a high quantum yield of reactive oxygen species, especially singlet oxygen ( 1 O 2 ), for efficiently killing tumor cells upon near-infrared light irradiation. Our first-principles calculations revealed that the observed high yield 1 O 2 resulted from the unique side-on parallel diatomic adsorption (Yeager mode) of triplet oxygen molecules on the highly conjugated porphyrin rings in the photoexcited COP-P-SO 3 H.

A Pyrolysis‐Free Covalent Organic Polymer for Oxygen Reduction

“…The as‐synthesized COP materials have very low solubility in water. To facilitate the self‐assembly between COP material and graphene by the attraction, we first prepared a better water‐dispersive porphyrin macrocycle‐based COP‐P material (termed as 1 ; Supporting Information, Table S1) with sulfonic acid side groups, COP‐P‐SO 3 H (termed as 2 ), by post‐synthetic modification according to our previous method (Supporting Information, Figure S3 and S4) . Moreover, considering the electronegativity of graphene oxide in solution, we further incorporated metal ion (for example, Co) into the fully conjugated polymer COP backbone via connecting with sulfonic acid side groups to further accelerate self‐assembly between COP material and graphene in the solution.…”

Covalent Organic Framework Electrocatalysts for Clean Energy Conversion

“…The multifunctional COFs can be prepared with different edge linkers . The nature of huge surface area, tunable structure, and relative derivative can create 2D and 3D COFs for various preponderant applications such as energy conversion, light absorption, and emission …”

Hybrid Nanomedicine Fabricated from Photosensitizer‐Terminated Metal–Organic Framework Nanoparticles for Photodynamic Therapy and Hypoxia‐Activated Cascade Chemotherapy

“…Photodynamic therapy (PDT) is an emerging treatment modality that can be turned on by remote laser illumination at the region of interest . Three vital components, namely, photosensitizer, O 2 , and specific exciting light are included in PDT . Upon exposure to specific laser irradiation, photosensitizer can be promoted to an excited triplet state, and transfer energy to surrounding O 2 to generate reactive oxygen species (ROS), especially singlet oxygen ( 1 O 2 ) that strikes the intracellular redox balance and consequently activates ROS‐mediated apoptosis .…”