Design and synthesis of efficient heavy-atom-free photosensitizers for photodynamic therapy of cancer.

Novel thiocarbonyl derivatives (NIS and CRNS) with excellent ROS generation abilities are synthesized and studied as potential photosensitizers for one- and two-photon excited photodynamic therapy. In particular, NIS-Me and CRNS display outstanding phototoxicity toward HeLa cells under two-photon excitation (800 nm) with negligible dark toxicity.

Fine-tuning the electronic structure of heavy-atom-free photosensitizers for fluorescence imaging and mitochondria-targeted photodynamic therapy.

Theranostics that combines both diagnosis and therapy into a single platform has recently emerged as a promising biomedical approach for cancer treatment; however, the development of efficient theranostic agents with excellent optical properties remains a challenge. Here, we report novel mitochondria-targeting photosensitizers (s) that possess considerable singlet oxygen generation capabilities and good fluorescence properties for imaging-guided photodynamic therapy (PDT). The incorporation of sulfur atoms into the π-conjugated skeleton of along with the introduction of different functional groups at the -position of the core is essential for tuning the photophysical and photosensitizing properties.

Molecular Design of Highly Efficient Heavy-Atom-Free Triplet BODIPY Derivatives for Photodynamic Therapy and Bioimaging.

Novel BODIPY photosensitizers were developed for imaging-guided photodynamic therapy. The introduction of a strong electron donor to the BODIPY core through a phenyl linker combined with the twisted arrangement between the donor and the BODIPY acceptor is essential for reducing the energy gap between the lowest singlet excited state and the lowest triplet state (ΔE ), leading to a significant enhancement in the intersystem crossing (ISC) of the BODIPYs. Remarkably, the BDP-5 with the smallest ΔE (ca.

An Emerging Molecular Design Approach to Heavy-Atom-Free Photosensitizers for Enhanced Photodynamic Therapy under Hypoxia.

A novel strategy for designing highly efficient and activatable photosensitizers that can effectively generate reactive oxygen species (ROS) under both normoxia and hypoxia is proposed. Replacing both oxygen atoms in conventional naphthalimides (RNI-) with sulfur atoms led to dramatic changes in the photophysical properties. The remarkable fluorescence quenching (Φ ≈ 0) of the resulting thionaphthalimides (RNI-) suggested that the intersystem crossing from the singlet excited state to the reactive triplet state was enhanced by the sulfur substitution.

Endoplasmic Reticulum-Targeted Ratiometric N-Heterocyclic Carbene Borane Probe for Two-Photon Microscopic Imaging of Hypochlorous Acid.

The naphthoimidazolium borane 4 is shown to be a selective probe for HOCl over other reactive oxygen species. Unlike other boronate-reactive oxygen species (ROS) fluorogenic probes that are oxidized by HOCl through a nucleophilic borono-Dakin oxidation mechanism, probe 4 is distinguished by its electrophilic oxidation mechanism involving B-H bond cleavage. Two-photon microscopy experiments in living cells and tissues with the probe 4 demonstrate the monitoring of endogenous HOCl generation and changes in HOCl concentrations generated in the endoplasmic reticulum during oxidative stress situations.