Vacancy-enhanced generation of singlet oxygen for photodynamic therapy

Removal of organic dyes from aqueous solution using a novel pyrene appended Zn(II)-based metal-organic framework and its photocatalytic properties

In this study, we report the efficient removal of organic dyes from aqueous solutions using a newly synthesized pyrene-appended Zn(II)-based metal-organic framework (MOF), ZnSiF6Pyrene MOF, with the chemical formula C52H32F6N4SiZn·4(CHCl3). The MOF was synthesized through a facile method at room temperature using a dipyridylpyrene ligand and ZnSiF6 metal source, resulting in a highly crystalline structure with pyrene functional groups forming the framework. The synthesized MOF was characterized using various analytical techniques, including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis, and scanning electron microscopy (SEM). Thermal stability was assessed using thermogravimetric analysis (TGA), while the surface area of the MOF was determined using a Brunauer-Emmett-Teller (BET) surface analyzer. Furthermore, the single-crystal X-ray diffraction (SCXRD) structure was studied to authenticate its solid-state structure. The as-synthesized MOF exhibited remarkable adsorption capacity towards various organic dyes, including Congo red (CR), rhodamine B (RhB), and methyl violet (MV), due to its ample surface area and strong π-π interactions between the pyrene moieties and dye molecules, as demonstrated by experimental and in silico docking studies. The photocatalytic degradation of MV dye was also investigated. Detailed trapping tests indicate that hydroxyl (˙OH) and superoxide (O2˙-) radicals are likely the primary active species responsible for the photodegradation of the dye under study. Furthermore, the photocatalytic property of the MOF was investigated under visible light irradiation, demonstrating excellent ability to generate singlet oxygen. This study highlights the potential of pyrene-appended Zn(II)-based MOFs as promising materials for environmental remediation applications.

Two-Dimensional Layered Heterojunctions for Photoelectrocatalysis

Two-dimensional (2D) layered nanomaterial heterostructures, arising from the combination of 2D materials with other low-dimensional species, feature a large surface area to volume ratio, which provides a high density of active sites for catalytic applications and for (photo)electrocatalysis (PEC). Meanwhile, their electronic band structure and high electrical conductivity enable efficient charge transfer (CT) between the active material and the substrate, which is essential for catalytic activity. In recent years, researchers have demonstrated the potential of a range of 2D material interfaces, such as graphene, graphitic carbon nitride (g-C3N4), metal chalcogenides (MCs), and MXenes, for (photo)electrocatalytic applications. For instance, MCs such as MoS2 and WS2 have shown excellent catalytic activity for hydrogen evolution, while graphene and MXenes have been used for the reduction of carbon dioxide to higher value chemicals. However, despite their great potential, there are still major challenges that need to be addressed to fully realize the potential of 2D materials for PEC. For example, their stability under harsh reaction conditions, as well as their scalability for large-scale production are important factors to be considered. Generating heterojunctions (HJs) by combining 2D layered structures with other nanomaterials is a promising method to improve the photoelectrocatalytic properties of the former. In this review, we inspect thoroughly the recent literature, to demonstrate the significant potential that arises from utilizing 2D layered heterostructures in PEC processes across a broad spectrum of applications, from energy conversion and storage to environmental remediation. With the ongoing research and development, it is likely that the potential of these materials will be fully expressed in the near future.

Oxygen Vacancy Defect Enhanced NIR-II Photothermal Performance of BiOxCl Nanosheets for Combined Phototherapy of Cancer Guided by Multimodal Imaging

Narrow photo-absorption range and low carrier utilization are significant barriers that restrict the antitumor efficiency of 2D bismuth oxyhalide (BiOX, X = Cl, Br, I) nanosheets (NSs). Introducing oxygen vacancy (OV) defects can expand the absorption range and improve carrier utilization, which are crucial but also challenging. In this study, a series of BiOxCl NSs with different OV defect concentrations (x = 1, 0.7, 0.5) is developed, which shows full spectrum absorption and strong absorption in the second near-infrared region (NIR-II). Density functional theory calculations are utilized to calculate the crystal structure and density states of BiOxCl, which confirm that part of the carriers is separated by OV enhanced internal electric field to improve carrier utilization. The carriers without redox reaction can be trapped in the OV, leading to great majority of photo-generated carriers promoting the photothermal performance. Triggered by single NIR-II (1064 nm), BiOxCl NSs' bidirectional efficient utilization of carriers achieves synchronously combined phototherapy, leading to enhanced tumor ablation and multimodal diagnostic in vitro and vivo. It is thus believed that this work provides an innovative strategy to design and construct nanoplatforms of indirect band gap semiconductors for clinical phototheranostics.

Dual Key-Activated Nir-I/II Fluorescence Probe for Monitoring Photodynamic and Photothermal Synergistic Therapy Efficacy

As cancer markers, hydrogen peroxide (H2 O2 ) and viscosity play an essential role in the development of tumors. Meanwhile, based on the performance of near-infrared (NIR) fluorescence imaging and the high efficiency of photodynamic therapy (PDT) and photothermal therapy (PTT) synergistic therapy, it is urgent to develop a dual-key (H2 O2 and viscosity) activated fluorescence probe for cancer phototherapy. Herein, a NIR-I/II fluorescence probe named BX-B is reported. In the presence of both H2 O2 and viscosity, the fluorescence signal of NIR-I (810 nm) and NIR-II (945 nm) can be released. In the presence of H2 O2 , the PDT and PTT effects are observed. BX-B is used to monitor its therapeutic effects in cancer cells and tumor-bearing mice due to the increased viscosity caused by PDT and PTT. In addition, the tumors of mice treated with BX-B are almost completely ablated after the laser irradiation based on its PDT and PTT synergistic therapy. This work provides a reliable platform for effective cancer treatment and immediate evaluation of therapeutic effects.

Discovery of New Hydrazone-Thiazole Polyphenolic Antioxidants through Computer-Aided Design and In Vitro Experimental Validation

Oxidative stress is linked to a series of diseases; therefore, the development of efficient antioxidants might be beneficial in preventing or ameliorating these conditions. Based on the structure of a previously reported compound with good antioxidant properties and on computational studies, we designed several catechol derivatives with enhanced antioxidant potential. The compounds were synthesized and physicochemically characterized, and their antioxidant activity was assessed through different antiradical, electron transfer and metal ions chelation assays, their electrochemical behavior and cytotoxicity were studied. The results obtained in the in vitro experiments correlated very well with the in silico studies; all final compounds presented very good antioxidant properties, generally superior to those of the reference compounds used. Similarly, the results obtained from studying the compounds' electrochemical behavior were in good agreement with the results of the antioxidant activity evaluation assays. Regarding the compounds' cytotoxicity, compound 7b had a dose-dependent inhibitory effect against all cell lines. In conclusion, through computer-aided design, we developed several catechol thiazolyl-hydrazones with excellent antioxidant properties, of which compound 7b, with two catechol moieties in its structure, exhibited the best antioxidant activity.

Controllable Synthesis of BiOCl with Z-Scheme (001)/(110) Facet Homojunction and their Photocatalytic Killing Effect on HePG2 Cells in vitro

In this study, a set of BiOCl with controllable ratios of (001) and (110) facets was prepared by adjusting the content of diethylene glycol (DEG) during the preparation process. The degradation experiment of bisphenol A (BPA) shows that under simulated sunlight, when the ratio of (001) to (110) is 0.61, BiOCl (BOC-2) has the best degradation activity, which can degrade 96.2% BPA within 20 min. After theoretical calculations and experimental characterization, a Z-scheme (001)/(110) facet homojunction is proposed. Then, three typical samples were selected to test the biological toxicity of HepG2 cells and the activity of killing HepG2 cells under ultraviolet light conditions. Studies have found that exposed facets play a more important role in the biotoxicity of BiOCl to cells; with a (001)/(110) ratio of 0.61, BOC-2 exhibits excellent endocytosis and phototoxicity but no obvious dark cytotoxicity, while with a (001)/(110) ratio of 0.15, BiOCl (BOC-4) has poor endocytosis and strong cytotoxicity under dark conditions. Through reactive oxygen species (ROS) and lactate dehydrogenase (LDH) assay detection, the process of photocatalytic killing cells of BOC-2 more looks like an apoptosis mechanism, while BOC-4 mainly causes cell necrosis.

Vacancy defect-promoted nanomaterials for efficient phototherapy and phototherapy-based multimodal Synergistic Therapy

Phototherapy and multimodal synergistic phototherapy (including synergistic photothermal and photodynamic therapy as well as combined phototherapy and other therapies) are promising to achieve accurate diagnosis and efficient treatment for tumor, providing a novel opportunity to overcome cancer. Notably, various nanomaterials have made significant contributions to phototherapy through both improving therapeutic efficiency and reducing side effects. The most key factor affecting the performance of phototherapeutic nanomaterials is their microstructure which in principle determines their physicochemical properties and the resulting phototherapeutic efficiency. Vacancy defects ubiquitously existing in phototherapeutic nanomaterials have a great influence on their microstructure, and constructing and regulating vacancy defect in phototherapeutic nanomaterials is an essential and effective strategy for modulating their microstructure and improving their phototherapeutic efficacy. Thus, this inspires growing research interest in vacancy engineering strategies and vacancy-engineered nanomaterials for phototherapy. In this review, we summarize the understanding, construction, and application of vacancy defects in phototherapeutic nanomaterials. Starting from the perspective of defect chemistry and engineering, we also review the types, structural features, and properties of vacancy defects in phototherapeutic nanomaterials. Finally, we focus on the representative vacancy defective nanomaterials recently developed through vacancy engineering for phototherapy, and discuss the significant influence and role of vacancy defects on phototherapy and multimodal synergistic phototherapy. Therefore, we sincerely hope that this review can provide a profound understanding and inspiration for the design of advanced phototherapeutic nanomaterials, and significantly promote the development of the efficient therapies against tumor.

Antioxidant Activity Evaluation and Assessment of the Binding Affinity to HSA of a New Catechol Hydrazinyl-Thiazole Derivative

Polyphenols have attained pronounced attention due to their ability to provide numerous health benefits and prevent several chronic diseases. In this study, we designed, synthesized and analyzed a water-soluble molecule presenting a good antioxidant activity, namely catechol hydrazinyl-thiazole (CHT). This molecule contains 3′,4′-dihydroxyphenyl and 2-hydrazinyl-4-methyl-thiazole moieties linked through a hydrazone group with very good antioxidant activity in the in vitro evaluations performed. A preliminary validation of the CHT developing hypothesis was performed evaluating in silico the bond dissociation enthalpy (BDE) of the phenol O-H bonds, compared to our previous findings in the compounds previously reported by our group. In this paper, we report the binding mechanism of CHT to human serum albumin (HSA) using biophysical methods in combination with computational studies. ITC experiments reveal that the dominant forces in the binding mechanism are involved in the hydrogen bond or van der Waals interactions and that the binding was an enthalpy-driven process. NMR relaxation measurements were applied to study the CHT–protein interaction by changing the drug concentration in the solution. A molecular docking study added an additional insight to the experimental ITC and NMR analysis regarding the binding conformation of CHT to HSA.

Factors that influence singlet oxygen formation vs. ligand substitution for light-activated ruthenium anticancer compounds

This review focuses on light-activated ruthenium anticancer compounds and the factors that influence which pathway is favored. Photodynamic therapy (PDT) is favored by π expansion and the presence of low-lying triplet excited states (e.g. ³MLCT, ³IL). Photoactivated chemotherapy (PACT) refers to light-driven ligand dissociation to give a toxic metal complex or a toxic ligand upon photo substitution. This process is driven by steric bulk near the metal center and weak metal-ligand bonds to create a low-energy ³MC state with antibonding character. With protic dihydroxybipyridine ligands, ligand charge can play a key role in these processes, with a more electron-rich deprotonated ligand favoring PDT and an electron-poor protonated ligand favoring PACT in several cases.

Recent advances in biological applications of nanomaterials through defect engineering

In recent years, defect engineering sprung up in the artificial nanomaterials (NMs) has attracted significant attention, since the physical and chemical properties of NMs could be largely optimized based on the rational control of different defect types and densities. Defective NMs equipped with the improved electric and catalytic ability, would be widely utilized as the photoelectric device and catalysts to alleviate the growing demands of industrial production and environmental treatments. In particular, considering that the features of targeting, adsorptive, loading and optical could be adjusted by the introduction of defects, numerous defective NMs are encouraged to be applied in the biological fields including bacterial inactivation, cancer therapy and so on. And this review is devoted to summarize the recent biological applications of NMs with abundant defects. Moreover, the opportunity of these defective NMs released into the surrounding environment continue to increase, the direct and indirect contact with biological molecules and organisms would be inevitable. Due to its high reactivity and adsorption triggered by defects, NMs tend to exhibit overestimate biological behaviors and effects on organisms. Thus, the sections regarding toxicological effects of NMs with abundant defects are also carried out to supplement the safety assessments of NMs and guide further applications in the industrial production and living.

Bismuth Oxychloride Nanomaterials Fighting for Human Health: From Photodegradation to Biomedical Applications

Environmental pollution and various diseases seriously affect the health of human beings. Photocatalytic nanomaterials (NMs) have been used for degrading pollution for a long time. However, the biomedical applications of photocatalytic NMs have only recently been investigated. As a typical photocatalytic NM, bismuth oxychloride (BiOCl) exhibits excellent photocatalytic performance due to its unique layered structure, electronic properties, optical properties, good photocatalytic activity, and stability. Some environmental pollutants, such as volatile organic compounds, antibiotics and their derivatives, heavy metal ions, pesticides, and microorganisms, could not only be detected but also be degraded by BiOCl-based NMs due to their excellent photocatalytic and photoelectrochemical properties. In particular, BiOCl-based NMs have been used as theranostic platforms because of their CT and photoacoustic imaging abilities, as well as photodynamic and photothermal performances. However, some reviews have only profiled the applications of dye degradation, hydrogen or oxygen production, carbon dioxide reduction, or nitrogen fixation of BiOCl NMs. There is a notable knowledge gap regarding the systematic study of the relationship between BiOCl NMs and human health, especially the biomedical applications of BiOCl-based NMs. As a result, in this review, the recent progress of BiOCl-based photocatalytic degradation and biomedical applications are summarized, and the improvement of BiOCl-based NMs in environmental and healthcare fields are also discussed. Finally, a few insights into the current status and future perspectives of BiOCl-based NMs are given.

Insight into the role of charge carrier mediation zone for singlet oxygen production over rod-shape graphitic carbon nitride: Batch and continuous-flow reactor

As a new approach of creating the photo-exited electron (e^-) and hole (h⁺) mediation zone for highly selective singlet oxygen (¹O₂) production, the rod-type graphitic carbon nitride (NCN) has been synthesized from the nitric acid-modified melamine followed by the calcination. The NCN exhibited a higher surface area and surface oxygen adsorption ability than bulk graphitic carbon nitride (BCN). The increment of CO and NH_x groups on NCN corresponded to e^- and h⁺ mediation groups, respectively, resulting in higher production of ¹O₂ than BCN. Moreover, those mediation groups on NCN result in higher recombination efficiency and longer e^- decay time. As a result, the optimized NCN-0.5 (derived from 0.5 M of nitric acid-modified melamine) displayed 5.8 times higher kinetic rate constant of atrazine (ATZ) removal under UVA-LED irradiation compared to BCN. This study also evaluated the ATZ degradation pathways and toxicity effect of by-products. In addition, continuous flow experiments using NCN-0.5 showed superior ATZ removal performance with a hybrid concept between a slurry photocatalysis and a continuous stirred tank reactor system using actual effluent obtained from a wastewater treatment plant. Thus, this work provides an insight into the strategy for highly selective ¹O₂ production and the potential for water purification application.

Ultrathin Nanosheet-Supported Ag@Ag2O Core-Shell Nanoparticles with Vastly Enhanced Photothermal Conversion Efficiency for NIR-II-Triggered Photothermal Therapy

Photothermal therapy (PTT) working in the second near-infrared (NIR-II) region has aroused a huge interest due to its potential application in terms of clinical cancer treatment. However, owing to the lack of photothermal nanoagents with high photothermal conversion efficiency, NIR-II-driven PTT still suffers from poor efficiency and subsequent cancer recurrence. In this work, we show a new and highly efficient preparation approach for NIR-II photothermal nanoagents and tailor ultrathin layered double hydroxide (LDH)-supported Ag@Ag₂O core-shell nanoparticles (Ag@Ag₂O/LDHs-U), vastly improving NIR-II photothermal performance. A combination study (high-resolution transmission electron microscopy (HRTEM), extended X-ray absorption fine structure spectroscopy (EXAFS), and X-ray photoelectron spectroscopy (XPS)) verifies that ultrafine Ag@Ag₂O core-shell nanoparticles (∼3.8 nm) are highly dispersed and firmly immobilized within ultrathin LDH nanosheets, and their Ag₂O shell possesses abundant vacancy-type defects. These unique Ag@Ag₂O/LDHs-U display an impressive photothermal conversion efficiency as high as 76.9% at 1064 nm. Such an excellent photothermal performance is likely attributed to the enhanced localized surface plasmon resonance (LSPR) coupling effect between Ag and Ag₂O and the reduced band gap caused by vacancy-type defects in the Ag₂O shell. Meanwhile, Ag@Ag₂O/LDHs-U also show prominent photothermal stability, due to the unique supported core-shell nanostructure. Moreover, both in vitro and in vivo studies further confirm that Ag@Ag₂O/LDHs-U possess good biocompatible properties and outstanding PTT therapeutic efficacy in the NIR-II region. This research shows a new strategy in the rational design and preparation of an efficient photothermal agent, which is helpful to achieve more accurate and effective cancer theranostics.

Recent developments on bismuth oxyhalide-based functional nanomaterials for biomedical applications

Multifunctional bismuth oxyhalide (BiOX, X = F, Cl, Br, and I) nanomaterials have great potential advantages in medical diagnostic and therapeutic applications. Pure BiOX nanomaterials have some limitations such as...

Recent advances in in situ oxygen-generating and oxygen-replenishing strategies for hypoxic-enhanced photodynamic therapy

Cancer is a leading cause of death worldwide, accounting for an estimated 10 million deaths by 2020. Over the decades, various strategies for tumor therapy have been developed and evaluated. Photodynamic therapy (PDT) has attracted increasing attention due to its unique characteristics, including low systemic toxicity and minimally invasive nature. Despite the excellent clinical promise of PDT, hypoxia is still the Achilles' heel associated with its oxygen-dependent nature related to increased tumor proliferation, angiogenesis, and distant metastases. Moreover, PDT-mediated oxygen consumption further exacerbates the hypoxia condition, which will eventually lead to the poor effect of drug treatment and resistance and irreversible tumor metastasis, even limiting its effective application in the treatment of hypoxic tumors. Hypoxia, with increased oxygen consumption, may occur in acute and chronic hypoxia conditions in developing tumors. Tumor cells farther away from the capillaries have much lower oxygen levels than cells in adjacent areas. However, it is difficult to change the tumor's deep hypoxia state through different ways to reduce the tumor tissue's oxygen consumption. Therefore, it will become more difficult to cure malignant tumors completely. In recent years, numerous investigations have focused on improving PDT therapy's efficacy by providing molecular oxygen directly or indirectly to tumor tissues. In this review, different molecular oxygen supplementation methods are summarized to alleviate tumor hypoxia from the innovative perspective of using supplemental oxygen. Besides, the existing problems, future prospects and potential challenges of this strategy are also discussed.

Self-Cycling Free Radical Generator from LDH-Based Nanohybrids for Ferroptosis-Enhanced Chemodynamic Therapy

Nonapoptotic ferroptosis has been a novel form of programmed cell death, which provides a new solution to enrich the anticancer treatment efficacy of traditional apoptotic therapeutic modality. Herein, a novel nanohybrid is designed by loading the PEG-encapsulated Artemisinin (denoted as A@P) on the ultrathin MgFe-LDH nanosheets (denoted as uLDHs) for improved chemodynamic therapy (CDT). The A@P/uLDHs cannot only realize the self-assembly between the Art and carrier but also be regarded as free radical generator. A comprehensive mechanistic study suggests that this unique A@P/uLDHs is able to in situ activate Art and self-cycling generate toxic C-centered free radical inside the cancer cells, without depending on abundant H₂ O₂ , accompanied with diminished cancerous antioxidation by depleting glutathione (GSH). The accumulation of ROS and depletion of GSH can further oxidize unsaturated fatty acid to generate lipid peroxide, whose overexpression can induce cell ferroptosis accompanied by cellular iron homeostasis turbulence. Both in vitro and in vivo results exhibit that A@P/uLDHs are an efficient nanoagent for highly efficient ferroptosis-enhanced CDT treatment. This work imparts the promising new visions about the ferroptosis-enhanced CDT via fine regulation of material design for improved cancer treatments.

Hierarchical multi-active component yolk-shell nanoreactors as highly active peroxymonosulfate activator for ciprofloxacin degradation

The reasonable design of the structure and composition of catalysts was essential to improve the catalytic performance of advanced oxidation processes (AOPs). Herein, we reported a simple strategy to synthesize hierarchical Co₃O₄-C@CoSiO_x yolk-shell nanoreactors with multiple active components by using metal-organic frameworks (MOFs). The novel nanoreactors are further used to activate peroxymonosulfate (PMS) for ciprofloxacin (CIP) degradation. The effects of reaction parameters (pH value, co-existing ions, reaction temperature, etc.) on CIP degradation were systematically investigated. Especially, ∼98.2% of CIP was degraded within 17 min under the optimal conditions, together with the low cobalt leaching and excellent reusability. The appreciable catalytic performance improvement might be due to the synergistic effect of the structure and component design: (1) the hierarchical yolk-shell structure endowed the catalyst with high surface area (∼232.47 m²/g) and fully exposed active sites; (2) abundant highly active ≡Co-OH⁺ were formed on the surface of CoSiO_x; (3) the presence of oxygen vacancies and nitrogen-doped carbon promoted the decomposition of PMS through a non-radical process. The results revealed both the radical (SO₄^∙-, ∙OH and O₂^∙-) and non-radical (¹O₂ and direct charge transfer) should be responsible for the CIP degradation. Moreover, the possible degradation pathways of CIP were proposed through the identification of intermediates using LC-MS/MS techniques and density functional theory (DFT) calculation. Our work highlights that multi-component catalysts derived from MOFs with novel structure have broad application prospects in AOPs.

Titanium carbide/zeolite imidazole framework-8/polylactic acid electrospun membrane for near-infrared regulated photothermal/photodynamic therapy of drug-resistant bacterial infections

Bacteria induced wound infection has become fatal healthcare issues needed to be resolved urgently. It is of vital importance to develop multifunctional therapeutic platforms to fight against increased bacterial antibiotic resistance. Herein, a titanium carbide (MXene)/zeolite imidazole framework-8 (ZIF-8)/polylactic acid (PLA) composite membrane (MZ-8/PLA) was fabricated through in-situ growth of ZIF-8 on MXene and the subsequent electrospinning process. It indicated MZ-8 can generate singlet oxygen and hyperthermia at photothermal (PTT) convention efficiency of 80.5% with bactericidal rate of more than 99.0%. In addition, MZ-8 showed remarkable antitumor efficiency in vitro and in vivo based on the combined photodynamic/photothermal therapy. Theoretical calculation illustrated MZ-8 could improve the laser activation process by acceleration of intermolecular charge transfer, reducing excitation energy, stabilizing excited states and increasing intersystem crossing rate. After incorporated into electrospun scaffolds, MZ-8/PLA exhibited potent PTT and photodynamic therapy (PDT) properties under 808 nm laser irradiation. The antibacterial rates of MZ-8/PLA were up to 99.9% and 99.8% against Escherichia coli and Methicillin-resistant staphylococcus aureus, respectively. In-vivo experimental results further confirmed that MZ-8/PLA can accelerate bacteria infected wound healing without observable resistance. This work opens a new avenue to design promising platforms for fighting against extremely drug resistant bacterial infection.

Engineering of CoSe2 Nanosheets via Vacancy Manipulation for Efficient Cancer Therapy

CoSe₂ nanosheets with different vacancy associates (i.e., V_SeSe, V_CoCoSe, V_CoSeSe, and V_CoCoCoSe) were synthesized by selecting different templates and calcination temperatures. The nanosheets having higher theoretical adsorption toward cellular membrane phospholipids exerted more damage to both artificial liposomes and cell membranes (V_SeSe > V_CoCoSe > V_CoCoCoSe > V_CoSeSe) and exhibited higher efficiency to kill tumor cells (e.g., A549 lung cancer cells and HeLa cervical cancer cells). Moreover, V_CoCoCoSe CoSe₂ nanosheets can be easily coated with the tumor-targeting protein transferrin (Tf), and these Tf-coated nanosheets (Tf-V_CoCoCoSe) drastically decreased the viability of various types of cancer cells (81%) without significantly damaging normal cells. Importantly, this treatment was more efficient in eliminating tumor tissues than the common chemotherapeutic drug oxaliplatin. Thus, this study offers proof of concept that manipulating the surface vacancies of CoSe₂ nanosheets could provide an efficient route for cancer therapy in a manner that could circumvent or minimize drug resistance development.

Highly efficient photothermal heating via distorted edge-defects in boron quantum dots

Quantum dots (QDs) are increasingly being utilized as near infrared (NIR) active photothermal agents for cancer diagnosis and therapy, with the main emphasis of current research being the enhancement of photothermal conversion efficiencies. Herein, we report the facile synthesis of 2-3 nm boron quantum dots (B QDs), which demonstrated a remarkable photothermal conversion efficiency of 57% under NIR excitation. This outstanding performance can be attributed to the alteration of the electronic structure, which was a result from the distorted edge-effect induced by the unique empty orbit of B atoms in the B QDs. These results can be verified by B K-edge near edge X-ray absorption fine structure (NEXAFS), high-resolution transmission electron microscopy (HR-TEM) and density functional theory (DFT) calculations. The results demonstrate that B QDs represent a promising new and non-toxic agent for both multimodal NIR-driven cancer imaging and photothermal therapy. This work thus identifies B QDs as an exciting new and theranostic agent for cancer therapy. Furthermore, the synthetic strategy used here to synthesize the B QDs was simple and easily scalable.

Facile synthesis of Au@Mn3O4 magneto-plasmonic nanoflowers for T1-weighted magnetic resonance imaging and photothermal therapy of cancer

The integration of advanced diagnostic contrast agents with versatile therapeutic nanoparticles presents an effective method for cancer treatment.

Highly Efficient Vacancy-Driven Photothermal Therapy Mediated by Ultrathin MnO2 Nanosheets

In medical applications, two-dimensional nanomaterials have been widely studied on account of their intriguing properties such as good biocompatibility, stability, and multifunctionality. Herein, an ultrathin MnO₂ nanosheet has been fabricated by a simplistic hydrothermal process. The high photothermal conversion performance (62.4%) can be attributed to the vacancy in the ultrathin MnO₂ nanosheet, as confirmed by the extended X-ray absorption fine structure results and the density functional theory calculation, benefiting photoacoustic imaging-guided cancer therapy. This highly efficient vacancy-induced photothermal therapy has been reported for the first time. As a result, this work demonstrates that this ultrathin MnO₂ nanosheet has a potential to construct a nanosystem for imaging-guided cancer therapy.

Theoretical study on the intrinsic properties of In2Se3/MoS2 as a photocatalyst driven by near-infrared, visible and ultraviolet light

Two-dimensional photocatalysts with full optical absorption have attracted widespread attention for water splitting and pollutant degradation, but only few single materials can meet this criterion.