Multilayer Microcapsules for FRET Analysis and Two-Photon-Activated Photodynamic Therapy

• Published in: Angewandte Chemie International Edition Vol. 55; no. 43; pp. 13538 - 13543
• Main Authors: Yang, Yang, Liu, Huiling, Han, Mingjuan, Sun, Bingbing, Li, Junbai
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 17.10.2016; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Assembly; Binding sites; Biodiversity; Biological analysis; Confocal microscopy; Dyes; Energy transfer; Fluorescence; Fluorescence resonance energy transfer; Fluorescence spectroscopy; FRET; Fretting; Lasers; Microcapsules; Microscopy; Photodynamic therapy; photosensitizers; Scanning microscopy; Spectroscopic analysis; Stability; Wall thickness; microcapsules; FRET; photosensitizers; dyes; photodynamic therapy
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201605905

Microcapsules obtained by layer‐by‐layer assembly provide a good platform for biological analysis owing to their component diversity, multiple binding sites, and controllable wall thickness. Herein, different assembly species were obtained from two‐photon dyes and traditional photosensitizers, and further assembled into microcapsules. Fluorescence resonance energy transfer (FRET) was shown to occur between the two‐photon dyes and photosensitizers. Confocal laser scanning microscopy (CLSM) with one‐ and two‐photon lasers, fluorescence lifetime imaging microscopy (FLIM), and time‐resolved fluorescence spectroscopy were used to analyze the FRET effects in the microcapsules. The FRET efficiency could easily be controlled through changing the assembly sequence. Furthermore, the capsules are phototoxic upon one‐ or two‐photon excitation. These materials are thus expected to be applicable in two‐photon‐activated photodynamic therapy for deep‐tissue treatment. A layer‐by‐layer approach was adopted for the synthesis of microcapsules containing two‐photon dyes (FITC) and traditional photosensitizers (RB) for two‐photon‐activated photodynamic therapy. The photosensitizers were indirectly activated by dyes in the same multilayer through one‐ or two‐photon‐induced Förster resonance energy transfer (FRET).