Novel high-quantum-yield polydiacetylene conjugated AIE micelles for amplified fluorescence signaling and photodynamic therapy

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2021-10, Vol.419, p.113461, Article 113461
• Main Authors: Cao, Menghui, Yin, Xiaoying, Luo, Xin, Qu, Yi, Zhang, Lin, Sun, Yun, Yan, Yinan
• Format: Article
• Language: English
• Subjects: Aggregation induced emission; Bioimaging; Photodynamic therapy; Polydiacetylene; Quantum yields; Reactive oxygen species
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2021.113461

[Display omitted] •Novel AIE micelles were assembled and crosslinked by the compound of NT grafted 10,12-pentacosadiynoic acid (PCDA-NT) and PCDA (mole ratio as 1:5).•Fluorescence quantum yield was significantly enhanced from 6.7% to 84%.•The DFT-calculated singlet–triplet energy gap (ΔEST = 0.37 eV) got reduced than the precursor.•Inactive AIE micelles exhibit good cell benignity, but superior reactive oxygen species (ROS) generation and high photocytotoxicity under irradiation. Improving the fluorescent quantum yields (FQYs) and the reactive oxygen species (ROS) generation ability is of great significance in AIEgen (aggregation induced emission luminogen) synthetic strategy. In this paper, we successfully integrated 10,12-Pentacosadiynoic acid (PCDA) bond with the AIEgen (4-triphenylamine naphthalimide skeletons, NT) to form a new type of macromolecule. The resultant molecule PCDA-NT displayed a strong orange fluorescence of 84% quantum yield, greatly intensified up-to 12.5 times associated with its precursor, and the calculated singlet–triplet energy gap of PCDA-NT was ultrasmall (ΔEST = 0.37 eV). Spherical AIE micelles (PCDA-NT and PCDA mole ratio as 1:5) were formulated by cross-linking “C≡C” alkyne groups in the micelles’ surficial layer under UV irradiation with low critical micelle concentration (CMC, 0.00487 mg/mL), also the crosslinked structure restricted PCDA-NT’s intramolecular rotation, which exhibited improved ROS generation. In-vitro experiment revealed that AIE micelles exhibited intense green fluorescence inside MC3T3E1 cells and displayed nontoxic nature in the un-activated state at the concentration from 0 to 25 µM. Furthermore, Cancer cell proliferation inhibition was observed on the effect of AIE micelles under irradiation switch at the dose of 15 μM, demonstrating the great potentials that can act a dual role as an imaging and phototherapeutic agent.