Self-assembly-integrated tumor targeting and electron transfer programming towards boosting tumor type I photodynamic therapy.

Type I photodynamic therapy (PDT) is attracting increasing interest as an effective solution to the poor prognosis of patients with hypoxic tumors. The development of functional type I photosensitizers is limited by a lack of feasible strategies to systematically modulate electron transfer (ET) in photosensitization. Herein, we present an easily accessible approach for the preparation of nanophotosensitizers with self-assembly-integrated tumor-targeting and ET programming towards boosting tumor type I PDT.

Integration of TADF Photosensitizer as "Electron Pump" and BSA as "Electron Reservoir" for Boosting Type I Photodynamic Therapy.

Type I photosensitization provides an effective solution to the problem of unsatisfactory photodynamic therapeutic (PDT) effects caused by the tumor hypoxia. The challenge in the development of Type I mode is to boost the photosensitizer's own electron transfer capacity. Herein, we found that the use of bovine serum albumin () to encapsulate a thermally activated delayed fluorescence (TADF) photosensitizer can significantly promote the Type I PDT process to generate a mass of superoxide anions (O).

Naphthofluorescein-based organic nanoparticles with superior stability for near-infrared photothermal therapy.

Photothermal agents (PTAs) based on organic small molecules with near-infrared (NIR) absorption (700-900 nm) have attracted increasing attention in cancer photothermal therapy (PTT). However, NIR organic PTAs often suffer from poor stability. Fluorescein and its derivatives have been widely used in biological imaging and sensing due to their minimal cytotoxicity.

An unexpected strategy to alleviate hypoxia limitation of photodynamic therapy by biotinylation of photosensitizers.

The most common working mechanism of photodynamic therapy is based on high-toxicity singlet oxygen, which is called Type II photodynamic therapy. But it is highly dependent on oxygen consumption. Recently, Type I photodynamic therapy has been found to have better hypoxia tolerance to ease this restriction.

Liposome-Based Nanoencapsulation of a Mitochondria-Stapling Photosensitizer for Efficient Photodynamic Therapy.

Mitochondria-targeting photodynamic therapy (PDT) can block mitochondrial function and trigger the inherent proapoptotic cascade signal of mitochondria, which has been considered to have the potential to amplify the efficiency of PDT. However, the dynamic change of mitochondrial membrane potential (MMP) makes most cationic photosensitizers easily fall off from the mitochondria, which greatly limits the efficiency of PDT. Here, we have developed a smart liposome encapsulation method based on a mitochondria-stapling photosensitizer for efficient theranostic photodynamic therapy.

A Dual-Nanozyme-Catalyzed Cascade Reactor for Enhanced Photodynamic Oncotherapy against Tumor Hypoxia.

Tumor hypoxia is a typical characteristic of tumor microenvironment (TME), which seriously compromises the therapeutic effect of photodynamic therapy (PDT). The development of nanozymes with oxygen-generation ability is a promising strategy to overcome the oxygen-dependent of PDT but remained a great challenge. Herein, a dual-nanozymes based cascade reactor HAMF is proposed to alleviate tumor hypoxia for enhanced PDT.

Constructing a Local Hydrophobic Cage in Dye-Doped Fluorescent Silica Nanoparticles to Enhance the Photophysical Properties.

Aggregation-caused quenching (ACQ) and poor photostability in aqueous media are two common problems for organic fluorescence dyes which cause a dramatic loss of fluorescence imaging quality and photodynamic therapy (PDT) failure. Herein, a local hydrophobic cage is built up inside near-infrared (NIR) cyanine-anchored fluorescent silica nanoparticles (FSNPs) in which a hydrophobic silane coupling agent (-octyltriethoxysilane, OTES) is doped into FSNPs for the first time to significantly inhibit the ACQ effect and inward diffusion of water molecules. Therefore, the obtained optimal FSNP-C with OTES-modification can provide hydrophobic repulsive forces to effectively inhibit the π-π stacking interaction of cyanine dyes and simultaneously reduce the formation of strong oxidizing species (•OH and HO) in reaction with HO, resulting in the best photostability (fluorescent intensity remained at 90.

Achieving long-lived thermally activated delayed fluorescence in the atmospheric aqueous environment by nano-encapsulation.

Fluorescent silica nanoparticles, which encapsulated dye DCF-BYT with thermally activated delayed fluorescence (TADF) were fabricated by a simple synthetic method. Even in the atmospheric aqueous environment, the obtained DCF-BYT nanoparticles exhibited extremely long TADF lifetime up to 9.33 ms, which imparts these nanoparticles with great potential in biological applications, like time-resolved fluorescence imaging.

A dual-targeted theranostic photosensitizer based on a TADF fluorescein derivative.

Specific diagnosis and therapy of cancer is still a challenge in biomedical research. Photodynamic therapy (PDT) has emerged as a novel therapeutic modality for cancer treatment. However, the traditional PDT photosensitizers often exhibit low specific selectivity.

Red-to-blue photon up-conversion with high efficiency based on a TADF fluorescein derivative.

A new photon up-conversion system with a TADF fluorescein derivative as a photosensitizer was developed to achieve a quite large anti-Stokes shift from red to blue with a fairly high up-conversion emission quantum yield. This TADF photosensitizer has a very small ΔEST to provide a 207 nm anti-Stokes shift photon up-conversion. Meanwhile, it has a quite long triplet state lifetime (22.