Protein-Activatable Diarylethene Monomer as a Smart Trigger of Noninvasive Control Over Reversible Generation of Singlet Oxygen: A Facile, Switchable, Theranostic Strategy for Photodynamic-Immunotherapy

Carbon Nitride Supported High-Loading Fe Single-Atom Catalyst for Activating of Peroxymonosulfate to Generate 1 O2 with 100 % Selectivity

Singlet oxygen (¹ O₂ ) is an excellent active species for the selective degradation of organic pollutions. However, it is difficult to achieve high efficiency and selectivity for the generation of ¹ O₂ . In this work, we develop a graphitic carbon nitride supported Fe single-atoms catalyst (Fe₁ /CN) containing highly uniform Fe-N₄ active sites with a high Fe loading of 11.2 wt %. The Fe₁ /CN achieves generation of 100 % ¹ O₂ by activating peroxymonosulfate (PMS), which shows an ultrahigh p-chlorophenol degradation efficiency. Density functional theory calculations results demonstrate that in contrast to Co and Ni single-atom sites, the Fe-N₄ sites in Fe₁ /CN adsorb the terminal O of PMS, which can facilitate the oxidization of PMS to form SO₅ ^.- , and thereafter efficiently generate ¹ O₂ with 100 % selectivity. In addition, the Fe₁ /CN exhibits strong resistance to inorganic ions, natural organic matter, and pH value during the degradation of organic pollutants in the presence of PMS. This work develops a novel catalyst for the 100 % selective production of ¹ O₂ for highly selective and efficient degradation of pollutants.

A light-activatable photosensitizer for photodynamic therapy based on a diarylethene derivative

Herein, a light-activatable photosensitizer based on a diarylethene derivative, DAE-TPE, was developed for photodynamic therapy. Upon UV exposure, the "opened" form (OF) of DAE-TPE NPs was converted to the "closed" form (CF), and photosensitization was activated. The CF of DAE-TPE NPs exhibited sufficient photodynamic therapy effects upon HeLa cells.

Deep Penetration of Nanolevel Drugs and Micrometer-Level T Cells Promoted by Nanomotors for Cancer Immunochemotherapy

The ability of nanomotors to promote the deep penetration of themselves and the loaded drugs in diseased tissues has been proposed and confirmed. However, whether such motion behavior of the nanomotors can also promote deep penetration of micrometer-sized immune cells in the diseased microenvironment, which is important for the immunotherapy of some diseases, has not been mentioned. Herein, we construct a nitric oxide (NO)-driven nanomotor that can move in the tumor microenvironment, focusing on its motion behavior and the role of NO, the beneficial product released during movement from this kind of nanomotor, in regulating the infiltration behavior and activity of immune cells. It can be found that the drug-loaded nanomotors with both NO-releasing ability and motility can promote the normalization of the tumor vasculature system and the degradation of the intrinsic extracellular matrix (ECM), which can significantly improve the tumor infiltration ability of T cells in vivo. The efficiency of T-cell infiltration in tumor tissue in vivo increased from 2.1 to 28.2%. Both subcutaneous and intraperitoneal implantation tumor models can validate the excellent antitumor effect of drug-loaded NO-driven nanomotors. This combination of motility of the power source from nanomotors and their physiological function offers a design idea for therapeutic agents for the future immunotherapy of many diseases.

Recent near-infrared light-activated nanomedicine toward precision cancer therapy

Light has been present throughout the history of mankind and even the universe. It is of great significance to human life, contributing to energy, agriculture, communication, and much more. In the biomedical field, light has been developed as a switch to control medical processes with minimal invasion and high spatiotemporal selectivity. During the past three years, near-infrared (NIR) light as long-wavelength light has been applied to more than 3000 achievements in biological applications due to its deep penetration depth and low phototoxicity. Remotely controlled cancer therapy usually involves the conversion of biologically inert NIR light. Thus, various materials, especially nanomaterials that can generate reactive oxygen species (ROS), ultraviolet (UV)/visual light, or thermal energy and so on under NIR illumination achieve great potential for the research of nanomedicine. Here, we offered an overview of recent advances in NIR light-activated nanomedicine for cancer therapeutic applications. NIR-light-conversion nanotechnologies for both directly triggering nanodrugs and smart drug delivery toward tumor therapy were discussed emphatically. The challenges and future trends of the use of NIR light in biomedical applications were also provided as a conclusion. We expect that this review will spark inspiration for biologists, materials scientists, pharmacologists, and chemists to fight against diseases and boost the future clinical-translational applications of NIR technology-based precision nanomedicine.

Photodynamic Therapy-Current Limitations and Novel Approaches

Photodynamic therapy (PDT) mostly relies on the generation of singlet oxygen, via the excitation of a photosensitizer, so that target tumor cells can be destroyed. PDT can be applied in the settings of several malignant diseases. In fact, the earliest preclinical applications date back to 1900’s. Dougherty reported the treatment of skin tumors by PDT in 1978. Several further studies around 1980 demonstrated the effectiveness of PDT. Thus, the technique has attracted the attention of numerous researchers since then. Hematoporphyrin derivative received the FDA approval as a clinical application of PDT in 1995. We have indeed witnessed a considerable progress in the field over the last century. Given the fact that PDT has a favorable adverse event profile and can enhance anti-tumor immune responses as well as demonstrating minimally invasive characteristics, it is disappointing that PDT is not broadly utilized in the clinical setting for the treatment of malignant and/or non-malignant diseases. Several issues still hinder the development of PDT, such as those related with light, tissue oxygenation and inherent properties of the photosensitizers. Various photosensitizers have been designed/synthesized in order to overcome the limitations. In this Review, we provide a general overview of the mechanisms of action in terms of PDT in cancer, including the effects on immune system and vasculature as well as mechanisms related with tumor cell destruction. We will also briefly mention the application of PDT for non-malignant diseases. The current limitations of PDT utilization in cancer will be reviewed, since identifying problems associated with design/synthesis of photosensitizers as well as application of light and tissue oxygenation might pave the way for more effective PDT approaches. Furthermore, novel promising approaches to improve outcome in PDT such as selectivity, bioengineering, subcellular/organelle targeting, etc. will also be discussed in detail, since the potential of pioneering and exceptional approaches that aim to overcome the limitations and reveal the full potential of PDT in terms of clinical translation are undoubtedly exciting. A better understanding of novel concepts in the field (e.g. enhanced, two-stage, fractional PDT) will most likely prove to be very useful for pursuing and improving effective PDT strategies.