Constructing Heavy-Atom-Free Photosensitizers for Hypoxic Tumor Phototherapy Based on Donor-Excited Photoinduced Electron-Transfer-Driven Type-I and Type-II Mechanisms.

The spin-orbit charge transfer intersystem crossing (SOCT-ISC) photophysical process has shown great potential for constructing heavy-atom-free photosensitizers (PSs) for photodynamic therapy (PDT) of tumors. However, for almost all such PSs reported to date, the SOCT-ISC is driven by the acceptor-excited photoinduced electron transfer (a-PeT). In this work, for the first time the donor-excited photoinduced electron transfer (d-PeT)-driven SOCT-ISC mechanism is utilized to construct the heavy-atom-free PSs for PDT of tumors by directly installing the electron-deficient N-alkylquinolinium unit (as an electron acceptor) into the meso-position of the near-infrared (NIR) distyryl Bodipy chromophore (as an electron donor). In the less polar environment, the PSs exist as the monomer and promote the production of singlet oxygen (1O2) (Type-II) relying on the d-PeT-driven population of the triplet excited state via SOCT-ISC, whereas in the aqueous environment, they exist as nanoaggregates and induce the generation of superoxides (O2-•) and hydroxyl radicals (HO•) (Type-I) via the d-PeT-driven formation of the delocalized charge-separated state. The PSs could rapidly be internalized into cancer cells and induce the simultaneous production of intracellular 1O2, O2-•, and HO• upon NIR light irradiation, endowing the PSs with superb photocytotoxicity with IC50 values up to submicromolar levels whether under normoxia or under hypoxia. Based on the PSs platform, a tumor-targetable PS is developed, and its abilities in killing cancer cells and in ablating tumors without damage to normal cells/tissues under NIR light irradiation are verified in vitro and in vivo. The study expands the design scope of PSs by introducing the d-PeT conception, thus being highly valuable for achieving novel PSs in the realm of tumor PDT.

A highly fluorescent and readily accessible all-organic photosensitizer model for advancing image-guided cancer PDT.

The potential of using image-guided photodynamic therapy (ig-PDT) for cancer, especially with highly biocompatible fluorescent agents free of heavy atoms, is well recognized. This is due to key advantages related to minimizing adverse side effects associated with standard cancer chemotherapy. However, this theragnostic approach is strongly limited by the lack of synthetically-accessible and easily-modulable chemical scaffolds, enabling the rapid design and construction of advanced agents for clinical ig-PDT. In fact, there are still very few ig-PDT agents clinically approved. Herein we report a readily accessible, easy-tunable and highly fluorescent all-organic small photosensitizer, as a model design for accelerating the development and translation of advanced ig-PDT agents for cancer. This scaffold is based on BODIPY, which assures high fluorescence, accessibility, and ease of performance adaptation by workable chemistry. The optimal PDT performance of this BODIPY dye, tested in highly resistant pancreatic cancer cells, despite its high fluorescent behavior, maintained even after fixation and cancer cell death, is based on its selective accumulation in mitochondria. This induces apoptosis upon illumination, as evidenced by proteomic studies and flow cytometry. All these characteristics make the reported BODIPY-based fluorescent photosensitizer a valuable model for the rapid development of ig-PDT agents for clinical use.

Graphene Quantum Dots Inhibit Lipid Peroxidation in Biological Membranes.

Excessive reactive oxygen species (ROS) in cellular environments leads to oxidative stress, which underlies numerous diseases, including inflammatory diseases, neurodegenerative diseases, cardiovascular diseases, and cancer. Oxidative stress can be particularly damaging to biological membranes such as those found in mitochondria, which are abundant with polyunsaturated fatty acids (PUFAs). Oxidation of these biological membranes results in concomitant disruption of membrane structure and function, which ultimately leads to cellular dysfunction. Graphene quantum dots (GQDs) have garnered significant interest as a therapeutic agent for numerous diseases that are linked to oxidative stress. Specifically, GQDs have demonstrated an ability to protect mitochondrial structure and function under oxidative stress conditions. However, the fundamental mechanisms by which GQDs interact with membranes in oxidative environments are poorly understood. Here, we used C11-BODIPY, a fluorescent lipid oxidation probe, to develop quantitative fluorescence assays that determine both the extent and rate of oxidation that occurs to PUFAs in biological membranes. Based on kinetics principles, we have developed a generalizable model that can be used to assess the potency of antioxidants that scavenge ROS in the presence of biological membranes. By augmenting our fluorescence assays with 1H NMR spectroscopy, the results demonstrate that GQDs scavenge nascent hydroxyl and peroxyl ROS that interact with membranes and that GQDs are potent inhibitors of ROS-induced lipid oxidation in PUFA-containing biological membranes. The antioxidant potency of GQDs is comparable to or even greater than established antioxidant molecules, such as ascorbic acid and Trolox. This work provides mechanistic insights into the mitoprotective properties of GQDs under oxidative stress conditions, as well as a quantitative framework for assessing antioxidant interactions in biological membrane systems.

Nanoparticles destabilizing the cell membranes triggered by NIR light for cancer imaging and photo-immunotherapy.

Cationic polymers have great potential for cancer therapy due to their unique interactions with cancer cells. However, their clinical application remains limited by their high toxicity. Here we show a cell membrane-targeting cationic polymer with antineoplastic activity (Pmt) and a second near-infrared (NIR-II) fluorescent biodegradable polymer with photosensitizer Bodipy units and reactive oxygen species (ROS) responsive thioketal bonds (PBodipy). Subsequently, these two polymers can self-assemble into antineoplastic nanoparticles (denoted mt-NPBodipy) which could further accumulate at the tumor and destroy cell membranes through electrostatic interactions, resulting in cell membrane destabilization. Meanwhile, the photosensitizer Bodipy produces ROS to induce damage to cell membranes, proteins, and DNAs to kill cancer cells concertedly, finally resulting in cell membrane lysis and cancer cell death. This work highlights the use of near-infrared light to spatially and temporarily control cationic polymers for photodynamic therapy, photo-immunotherapy, and NIR-II fluorescence for bio-imaging.

Boron Dipyrromethene-Based Nanotheranostic System for Sonophotoassisted Therapy and Simultaneous Monitoring of Tumor Immune Microenvironment Reprogramming.

Therapy-induced modulation of the tumor microenvironment (TME) to overcome the immunosuppressive TME is considered to be an opportunity for cancer treatment. However, monitoring of TME modulation during the therapeutic process to accurately determine immune responses and adjust treatment plans in a timely manner remains to be challenging. Herein, we report a carrier-free nanotheranostic system (CANPs) assembled by two boron dipyrromethene (BODIPY) dyes, a sonophotosensitizer C-BDP, and a nitric oxide (NO) probe amino-BODIPY (A-BDP). CANPs can exert combined sonophototherapeutic effects of C-BDP under ultrasound and light irradiation and simultaneously induce inflammatory TME, as well as emit bright fluorescence via A-BDP by monitoring tumor-associated macrophages (TAMs) repolarization through the released NO in vitro and in vivo. Of note, transforming growth factor-ß (TGF-ß) could be the key cytokine involved in the sonophototherapy-induced TME reprogramming. By virtue of high physiological stability, good biocompatibility, and effective tumor targetability, CANPs could be a potential nanotheranostic system for the simultaneous induction and detection of TME reprogramming triggered by sonophototherapy.

Hydrogen peroxide responsive theranostics for cancer-selective activation of DNA alkylators and real-time fluorescence monitoring in living cells.

Triple negative breast cancer (TNBC) is a notoriously difficult disease to treat, and many of the existing TNBC chemotherapeutics lack tumor selectivity and the capability for simultaneously visualizing and monitoring their own activity in the biological context. However, TNBC cells have been known to generate high levels of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). To this end, three novel small molecule theranostics 1a, 1c, and 2 consisting of both H2O2-responsive nitrogen mustard prodrug and profluorophore character have been designed, synthesized, and evaluated as targeted cancer therapeutics and bioimaging agents. The three theranostics comprise of boronate esters that deactivate nitrogen mustard functional groups and fluorophores but allow their selective activation through H2O2-specific oxidative deboronation for the release of the active drug and fluorophore. The three theranostics demonstrated H2O2-inducible DNA-alkylating capability and fluorescence turn-on properties in addition to selective anticancer activity. They are particularly effective in killing TNBC MDA-MB-468 cells with high H2O2 level while safe to normal epithelial MCF-10A cell. The conjugated boron-masked fluorophores in 1c and 2 are highly responsive towards H2O2, which enabled tracking of the theranostics in living cellular mitochondria and nucleus organelles. The three theranostics 1a, 1c, and 2 are capable of both selective release of the active drug to take effect in H2O2-rich cancer sites and simultaneously monitoring its activity. This single molecule system is of utmost importance to understand the function, efficacy, and mechanism of the H2O2-activated prodrugs and theranostics within the living recipient.

Cell-cycle dependence on the biological effects of boron neutron capture therapy and its modification by polyvinyl alcohol.

Boron neutron capture therapy (BNCT) is a unique radiotherapy of selectively eradicating tumor cells using boron compounds (e.g., 4-borono-L-phenylalanine [BPA]) that are heterogeneously taken up at the cellular level. Such heterogenicity potentially reduces the curative efficiency. However, the effects of temporospatial heterogenicity on cell killing remain unclear. With the technical combination of radiation track detector and biophysical simulations, this study revealed the cell cycle-dependent heterogenicity of BPA uptake and subsequent biological effects of BNCT on HeLa cells expressing fluorescent ubiquitination-based cell cycle indicators, as well as the modification effects of polyvinyl alcohol (PVA). The results showed that the BPA concentration in the S/G2/M phase was higher than that in the G1/S phase and that PVA enhances the biological effects both by improving the uptake and by canceling the heterogenicity. These findings might contribute to a maximization of therapeutic efficacy when BNCT is combined with PVA and/or cell cycle-specific anticancer agents.

Targeting a microbiota Wolbachian aminoacyl-tRNA synthetase to block its pathogenic host.

The interplay between humans and their microbiome is crucial for various physiological processes, including nutrient absorption, immune defense, and maintaining homeostasis. Microbiome alterations can directly contribute to diseases or heighten their likelihood. This relationship extends beyond humans; microbiota play vital roles in other organisms, including eukaryotic pathogens causing severe diseases. Notably, Wolbachia, a bacterial microbiota, is essential for parasitic worms responsible for lymphatic filariasis and onchocerciasis, devastating human illnesses. Given the lack of rapid cures for these infections and the limitations of current treatments, new drugs are imperative. Here, we disrupt Wolbachia's symbiosis with pathogens using boron-based compounds targeting an unprecedented Wolbachia enzyme, leucyl-tRNA synthetase (LeuRS), effectively inhibiting its growth. Through a compound demonstrating anti-Wolbachia efficacy in infected cells, we use biophysical experiments and x-ray crystallography to elucidate the mechanism behind Wolbachia LeuRS inhibition. We reveal that these compounds form adenosine-based adducts inhibiting protein synthesis. Overall, our study underscores the potential of disrupting key microbiota to control infections.

Computational therapeutic repurposing of tavaborole targeting arginase-1 for venous leg ulcer.

Venous leg ulcers (VLUs) pose a growing healthcare challenge due to aging, obesity, and sedentary lifestyles. Despite various treatments available, addressing the complex nature of VLUs remains difficult. In this context, this study investigates repurposing boronated drugs to inhibit arginase 1 activity for VLU treatment. The molecular docking study conducted by Schrodinger GLIDE targeted the binuclear manganese cluster of arginase 1 enzyme (2PHO). Further, the ligand-protein complex was subjected to molecular dynamic studies at 500 ns in Gromacs-2019.4. Trajectory analysis was performed using the GROMACS simulation package of protein RMSD, RMSF, RG, SASA, and H-Bond. The docking study revealed intriguing results where the tavaborole showed a better docking score (-3.957 Kcal/mol) compared to the substrate L-arginine (-3.379 Kcal/mol) and standard L-norvaline (-3.141 Kcal/mol). Tavaborole interaction with aspartic acid ultimately suggests that the drug molecule binds to the catalytic site of arginase 1, potentially influencing the enzyme's function. The dynamics study revealed the compounds' stability and compactness of the protein throughout the simulation. The RMSD, RMSF, SASA, RG, inter and intra H-bond, PCA, FEL, and MMBSA studies affirmed the ligand-protein and protein complex flexibility, compactness, binding energy, van der waals energy, and solvation dynamics. These results revealed the stability and the interaction of the ligand with the catalytic site of arginase 1 enzyme, triggering the study towards the VLU treatment.

A Novel Boron Dipyrromethene-Erlotinib Conjugate for Precise Photodynamic Therapy against Liver Cancer.

Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage and sunlight in traditional PDT can result in damage to healthy tissues, due to the low tumor selectivity of currently available photosensitizers (PSs). To address this challenge, we introduce herein a new strategy where the small molecule-targeted agent, erlotinib, is integrated into a boron dipyrromethene (BODIPY)-based PS to form conjugate 6 to enhance the precision of PDT. This conjugate demonstrates optical absorption, fluorescence emission, and singlet oxygen generation efficiency comparable to the reference compound 7, which lacks erlotinib. In vitro studies reveal that, after internalization, conjugate 6 predominantly accumulates in the lysosomes of HepG2 cells, exhibiting significant photocytotoxicity with an IC50 value of 3.01 µM. A distinct preference for HepG2 cells over HELF cells is observed with conjugate 6 but not with compound 7. In vivo experiments further confirm that conjugate 6 has a specific affinity for tumor tissues, and the combination treatment of conjugate 6 with laser illumination can effectively eradicate H22 tumors in mice with outstanding biosafety. This study presents a novel and potential PS for achieving precise PDT against cancer.

Targeted Photoconvertible BODIPYs Based on Directed Photooxidation-Induced Conversion for Applications in Photoconversion and Live Super-Resolution Imaging.

Photomodulable fluorescent probes are drawing increasing attention due to their applications in advanced bioimaging. Whereas photoconvertible probes can be advantageously used in tracking, photoswitchable probes constitute key tools for single-molecule localization microscopy to perform super-resolution imaging. Herein, we shed light on a red and far-red BODIPY, namely, BDP-576 and BDP-650, which possess both properties of conversion and switching. Our study demonstrates that these pyrrolyl-BODIPYs convert into typical green- and red-emitting BODIPYs that are perfectly adapted to microscopy. We also showed that this pyrrolyl-BODIPYs undergo Directed Photooxidation Induced Conversion, a photoconversion mechanism that we recently introduced, where the pyrrole moiety plays a central role. These unique features were used to develop targeted photoconvertible probes toward different organelles or subcellular units (plasma membrane, mitochondria, nucleus, actin, Golgi apparatus, etc.) using chemical targeting moieties and a Halo tag. We notably showed that BDP-650 could be used to track intracellular vesicles over more than 20 min in two-color imagings with laser scanning confocal microscopy, demonstrating its robustness. The switching properties of these photoconverters were studied at the single-molecule level and were then successfully used in live single-molecule localization microscopy in epithelial cells and neurons. Both membrane- and mitochondria- targeted probes could be used to decipher membrane 3D architecture and mitochondrial dynamics at the nanoscale. This study builds a bridge between the photoconversion and photoswitching properties of probes undergoing directed photooxidation and shows the versatility and efficacy of this mechanism in advanced live imaging.

Near-infrared BODIPY photosensitizers for two-photon excited singlet oxygen generation and tumor cell photodynamic therapy.

In this paper, two near-infrared BODIPY photosensitizers, Id-BDPI and Cz-BDPI, were obtained by modifying the indole and carbazole aromatic heterocycles in the core of BODIPY. The maximum absorption wavelengths of Id-BDPI and Cz-BDPI were 694 nm and 722 nm, and their singlet oxygen yields were 48% and 48.4%, respectively. In the simulated tumor cell photodynamic therapy, Id-BDPI and Cz-BDPI could effectively inhibit the growth of A549 tumor cells under near-infrared light. Meanwhile, the lysosomal co-localization coefficients of Id-BDPI and Cz-BDPI with A549 tumor cells were 0.94 and 0.89, respectively, showing high lysosomal targeting ability and biocompatibility. The two-photon absorption cross sections measured at 1050 nm by the Z-scanning method were 661.8 GM and 715.6 GM, respectively, and Cz-BDPI was further successfully applied to two-photon fluorescence imaging and two-photon excited singlet oxygen generation in zebrafish. The above results indicate that the introduction of aromatic heterocycles can effectively enhance the photodynamic efficacy of BODIPY photosensitizers, and the larger two-photon absorption cross section also brings potential for two-photon photodynamic therapy applications.

Recent progress of nano-drugs in neutron capture therapy.

As a developing radiation treatment for tumors, neutron capture therapy (NCT) has less side effects and a higher efficacy than conventional radiation therapy. Drugs with specific isotopes are indispensable counterparts of NCT, as they are the indespensable part of the neutron capture reaction. Since the creation of the first and second generations of boron-containing reagents, NCT has significantly advanced. Notwithstanding, the extant NCT medications, predominantly comprised of small molecule boron medicines, have encountered challenges such monofunctionality, inadequate targeting of tumors, and hypermetabolism. There is an urgent need to promote the research and development of new types of NCT drugs. Bio-nanomaterials can be introduced into the realm of NCT, and nanotechnology can give conventional medications richer functionality and significant adaptability. This can complement the advantages of each other and is expected to develop more new drugs with less toxicity, low side effects, better tumor targeting, and high biocompatibility. In this review, we summarized the research progress of nano-drugs in NCT based on the different types and sources of isotopes used, and introduced the attempts and efforts made by relevant researchers in combining nanomaterials with NCT, hoping to provide pivotal references for promoting the development of the field of tumor radiotherapy.

Nanometabolomics Elucidated Biological Prospective of Mo4/3B2-x Nanosheets: Toward Metabolic Reprogramming of Amino Acid Metabolism.

Mo4/3B2-x nanosheets are newly developed, and 2D transition metal borides (MBene) were reported in 2021, but there is no report on their further applications and modification; hence, this article sheds light on the significance of potential biological prospects for future biomedical applications. Therefore, elucidation of the biocompatibility, biotoxicology, and bioactivity of Mo4/3B2-x nanosheets has been an urgent need to be fulfilled. Nanometabolomics (also referred as nanomaterials-based metabolomics) was first proposed and utilized in our previous work, which specialized in interpreting nanomaterials-induced metabolic reprogramming through aqueous metabolomics and lipidomics approach. Hence, nanometabolomics could be considered as a novel concept combining nanoscience and metabolomics to provide bioinformation on nanomaterials' biomedical applications. In this work, the safe range of concentration (<50 mg/L) with good biosafety toward human umbilical vein endothelial cells (HUVECs) was discovered. The low concentration (5 mg/L) and high concentration (50 mg/L) of Mo4/3B2-x nanosheets were utilized for the in vitro Mo4/3B2-x-cell interaction. Nanometabolomics has elucidated the biological prospective of Mo4/3B2-x nanosheets via monitoring its biocompatibility and metabolic shift of HUVECs. The results revealed that 50 mg/L Mo4/3B2-x nanosheets could lead to a stronger alteration of amino acid metabolism with disturbance of the corresponding amino acid-related pathways (including amino acid metabolism, amino acid degradation, fatty acid biosynthesis, and lipid biosynthesis and metabolism). These interesting results were closely involved with the oxidative stress and production of excess ROS. This work could be regarded as a pathbreaking study on Mo4/3B2-x nanosheets at a biological level, which also designates their further biochemical, medical, and industrial application and development based on nanometabolomics bioinformation.

ß-Galactosidase-Triggered Photodynamic Elimination of Senescent Cells with a Boron Dipyrromethene-Based Photosensitizer.

Senescence is a cellular response having physiological and reparative functions to preserve tissue homeostasis and suppress tumor growth. However, the accumulation of senescent cells would cause deleterious effects that lead to age-related dysfunctions and cancer progression. Hence, selective detection and elimination of senescent cells are crucial yet remain a challenge. A ß-galactosidase (ß-gal)-activated boron dipyrromethene (BODIPY)-based photosensitizer (compound 1) is reported here that can selectively detect and eradicate senescent cells. It contains a galactose moiety connected to a pyridinium BODIPY via a self-immolative nitrophenylene linker, of which the photoactivity is effectively quenched. Upon interactions with the senescence-associated ß-gal, it undergoes enzymatic hydrolysis followed by self-immolation, leading to the release of an activated BODIPY moiety by which the fluorescence emission and singlet oxygen generation are restored. The ability of 1 to detect and eliminate senescent cells is demonstrated in vitro and in vivo, using SK-Mel-103 tumor-bearing mice treated with senescence-inducing therapy. The results demonstrate that 1 can be selectively activated in senescent cells to trigger a robust senolytic effect upon irradiation. This study breaks new ground in the design and application of new senolytic agents based on photodynamic therapy.

Boron Neutron Capture Therapy Enhanced by Boronate Ester Polymer Micelles: Synthesis, Stability, and Tumor Inhibition Studies.

Boron neutron capture therapy (BNCT) targets invasive, radioresistant cancers but requires a selective and high B-10 loading boron drug. This manuscript investigates boron-rich poly(ethylene glycol)-block-(poly(4-vinylphenyl boronate ester)) polymer micelles synthesized via atom transfer radical polymerization for their potential application in BNCT. Transmission electron microscopy (TEM) revealed spherical micelles with a uniform size of 43 ± 10 nm, ideal for drug delivery. Additionally, probe sonication proved effective in maintaining the micelles' size and morphology postlyophilization and reconstitution. In vitro studies with B16-F10 melanoma cells demonstrated a 38-fold increase in boron accumulation compared to the borophenylalanine drug for BNCT. In vivo studies in a B16-F10 tumor-bearing mouse model confirmed enhanced tumor selectivity and accumulation, with a tumor-to-blood (T/B) ratio of 2.5, surpassing BPA's T/B ratio of 1.8. As a result, mice treated with these micelles experienced a significant delay in tumor growth, highlighting their potential for BNCT and warranting further research.

Heavy-atom-free BODIPY dendrimer: utilizing the spin-vibronic coupling mechanism for two-photon photodynamic therapy in zebrafish.

In this study, the heavy-atom-free BODIPY dendrimer TM4-BDP was synthesized for near-infrared photodynamic therapy, and was composed of a triphenylamine-BODIPY dimer and four 1-(2-morpholinoethyl)-1H-indole-3-ethenyl groups. The TM4-BDP could achieve near-infrared photodynamic therapy through two different photosensitive pathways, which include one-photon excitation at 660 nm and two-photon excitation at 1000 nm. In the one-photon excitation pathway, the TM4-BDP could generate singlet oxygen and superoxide radicals under 660 nm illumination. In addition, the one-photon PDT experiment in human nasopharyngeal carcinoma (CNE-2) cells also indicated that the TM4-BDP could specifically accumulate in lysosomes and show great cell phototoxicity with an IC50 of 22.1 µM. In the two-photon excitation pathway, the two-photon absorption cross-section at 1030 nm of TM4-BDP was determined to be 383 GM, which means that it could generate reactive oxygen species (ROS) under 1000 nm femtosecond laser excitation. Moreover, the two-photon PDT experiment in zebrafish also indicated the TM4-BDP could be used for two-photon fluorescence imaging and two-photon induced ROS generation in biological environments. Furthermore, in terms of the ROS generation mechanism, the TM4-BDP employed a novel spin-vibronic coupling intersystem crossing (SV-ISC) process for the mechanism of ROS generation and the femtosecond transient absorption spectra indicated that this novel SV-ISC mechanism was closely related to its charge transfer state lifetime. These above experiments of TM4-BDP demonstrate that the dendrimer design is an effective strategy for constructing heavy-atom-free BODIPY photosensitizers in the near-infrared region and lay the foundation for two-photon photodynamic therapy in future clinical trials.

Fluorinated BPA derivatives enhanced 10B delivery in tumors.

Boron neutron capture therapy (BNCT) is an emerging approach for treating malignant tumors with binary targeting. However, its clinical application has been hampered by insufficient 10B accumulation in tumors and low 10B concentration ratios of tumor-to-blood (T/B) and tumor-to-normal tissue (T/N). Herein, we developed fluorinated BPA derivatives with different fluorine groups as boron delivery agents for enabling sufficient 10B accumulation in tumors and enhancing T/B and T/N ratios. Our findings demonstrated that fluorinated BPA derivatives had good biological safety. Furthermore, fluorinated BPA derivatives showed improved 10B accumulation in tumors and enhanced T/B and T/N ratios compared to the clinical boron drug fructose-BPA (f-BPA). In particular, in B16-F10 tumor-bearing mice, fluorinated BPA derivatives met the requirements for clinical BNCT even at half of the clinical dose. Thus, fluorinated BPA derivatives are potentially effective boron delivery agents for clinical BNCT in melanoma.

A Pt nanoenzyme- and BODIPY-loaded nanoscale covalent organic framework for relieving intratumoural hypoxia to enhance photodynamic therapy.

Herein, we report a composite COF material loaded with a Pt nanoenzyme and an organic photosensitizer BODIPY, synthesized via a stepwise post-synthetic modification. The obtained Pt@COF-BDP nanoparticles can efficiently and continuously convert H2O2 to O2, thereby increasing the efficiency of single-linear oxygen production and achieving efficient tumor inhibition.

TRPV3 activation by different agonists accompanied by lipid dissociation from the vanilloid site.

TRPV3 represents both temperature- and ligand-activated transient receptor potential (TRP) channel. Physiologically relevant opening of TRPV3 channels by heat has been captured structurally, while opening by agonists has only been observed in structures of mutant channels. Here, we present cryo-EM structures that illuminate opening and inactivation of wild-type human TRPV3 in response to binding of two types of agonists: either the natural cannabinoid tetrahydrocannabivarin (THCV) or synthetic agonist 2-aminoethoxydiphenylborane (2-APB). We found that THCV binds to the vanilloid site, while 2-APB binds to the S1-S4 base and ARD-TMD linker sites. Despite binding to distally located sites, both agonists induce similar pore opening and cause dissociation of a lipid that occupies the vanilloid site in their absence. Our results uncover different but converging allosteric pathways through which small-molecule agonists activate TRPV3 and provide a framework for drug design and understanding the role of lipids in ion channel function.