Integrated lithium niobate microwave photonic processing engine.

Integrated microwave photonics (MWP) is an intriguing technology for the generation, transmission and manipulation of microwave signals in chip-scale optical systems1,2. In particular, ultrafast processing of analogue signals in the optical domain with high fidelity and low latency could enable a variety of applications such as MWP filters3-5, microwave signal processing6-9 and image recognition10,11. An ideal integrated MWP processing platform should have both an efficient and high-speed electro-optic modulation block to faithfully perform microwave-optic conversion at low power and also a low-loss functional photonic network to implement various signal-processing tasks. Moreover, large-scale, low-cost manufacturability is required to monolithically integrate the two building blocks on the same chip. Here we demonstrate such an integrated MWP processing engine based on a 4 inch wafer-scale thin-film lithium niobate platform. It can perform multipurpose tasks with processing bandwidths of up to 67 GHz at complementary metal-oxide-semiconductor (CMOS)-compatible voltages. We achieve ultrafast analogue computation, namely temporal integration and differentiation, at sampling rates of up to 256 giga samples per second, and deploy these functions to showcase three proof-of-concept applications: solving ordinary differential equations, generating ultra-wideband signals and detecting edges in images. We further leverage the image edge detector to realize a photonic-assisted image segmentation model that can effectively outline the boundaries of melanoma lesion in medical diagnostic images. Our ultrafast lithium niobate MWP engine could provide compact, low-latency and cost-effective solutions for future wireless communications, high-resolution radar and photonic artificial intelligence.

7-Methoxy-13-dehydroxypaxilline: New indole diterpenoid from an endophytic fungus Penicillium sp. Nb 19.

ABSTACTA chemical investigation of the endophyte Penicillium sp. Nb 19, isolated from leaves of the traditionally medical plant Baphicacanthus cusia (Nees) Bremek., yielded one new indole diterpenoid, 7-methoxy-13-dehydroxypaxilline (1) together with seven known metabolites (2-8). The obtained structure of compound 1 was elucidated by its spectroscopic data. In addition, the absolute configuration of compound 6 was confirmed by ECD for the first time. Compounds 1-6 were evaluated for antitumor activity against MCF-7, HepG2, and HCCC-9810 cell lines.

Nanobody-based trispecific T cell engager (Nb-TriTE) enhances therapeutic efficacy by overcoming tumor-mediated immunosuppression.

BACKGROUND: T cell engagers (TCEs) have been established as an emerging modality for hematologic malignancies, but solid tumors remain refractory. However, the upregulation of programmed cell death 1 (PD-1) is correlated with T cell dysfunction that confer tumor-mediated immunosuppression. Developing a novel nanobody-based trispecific T cell engager (Nb-TriTE) would be a potential strategy to improve therapeutic efficacy. METHODS: Given the therapeutic potential of nanobodies (Nbs), we first screened Nb targeting fibroblast activation protein (FAP) and successfully generated a Nb-based bispecific T cell engager (Nb-BiTE) targeting FAP. Then, we developed a Nb-TriTE by fusing an anti-PD-1 Nb to the Nb-BiTE. The biological activity and antitumor efficacy of the Nb-TriTE were evaluated in vitro and in both cell line-derived and patient-derived xenograft mouse models. RESULTS: We had for the first time successfully selected a FAP Nb for the generation of novel Nb-BiTE and Nb-TriTE, which showed good binding ability to their targets. Nb-TriTE not only induced robust tumor antigen-specific killing, potent T cell activation and enhanced T cell function in vitro, but also suppressed tumor growth, improved survival and mediated more T cell infiltration than Nb-BiTE in mouse models of different solid tumors without toxicity. CONCLUSIONS: This novel Nb-TriTE provides a promising and universal platform to overcome tumor-mediated immunosuppression and improve patient outcomes in the future.

In-situ formation of niobium oxide - Niobium carbide - Reduced graphene oxide ternary nanocomposite as an electrochemical sensor for sensitive detection of anticancer drug methotrexate.

Engineering the nanostructure of an electrocatalyst is crucial in developing a high-performance electrochemical sensor. This work exhibits the hydrothermal followed by annealing synthesis of niobium oxide/niobium carbide/reduced graphene oxide (NbO/NbC/rGO) ternary nanocomposite. The oval-shaped NbO/NbC nanoparticles cover the surface of rGO evenly, and the rGO nanosheets are interlinked to produce a micro-flower-like architecture. The NbO/NbC/rGO nanocomposite-modified electrode is presented here for the first time for the rapid and sensitive electrochemical detection of the anticancer drug methotrexate (MTX). Down-sized NbO/NbC nanoparticles and rGO's high surface area provide many active sites with a rapid electron transfer rate, making them ideal for MTX detection. In comparison to previously reported MTX sensors, the developed drug sensor exhibits a lower oxidation potential and a higher peak current responsiveness. The constructed sensors worked analytically well under optimal conditions, as shown by a low detection limit of 1.6 nM, a broad linear range of 0.1-850 µM, and significant recovery findings (∼98 %, (n = 3)) in real samples analysis. Thus, NbO/NbC/rGO nanocomposite material for high-performance electrochemical applications seems promising.

Extensive Investigation on the Effect of Niobium Insertion on the Physical and Biological Properties of 45S5 Bioactive Glass for Dental Implant.

Dental implants have emerged as one of the most consistent and predictable treatments in the oral surgery field. However, the placement of the implant is sometimes associated with bacterial infection leading to its loss. In this work, we intend to solve this problem through the development of a biomaterial for implant coatings based on 45S5 Bioglass® modified with different amounts of niobium pentoxide (Nb2O5). The structural feature of the glasses, assessed by XRD and FTIR, did not change in spite of Nb2O5 incorporation. The Raman spectra reveal the Nb2O5 incorporation related to the appearance of NbO4 and NbO6 structural units. Since the electrical characteristics of these biomaterials influence their osseointegration ability, AC and DC electrical conductivity were studied by impedance spectroscopy, in the frequency range of 102-106 Hz and temperature range of 200-400 K. The cytotoxicity of glasses was evaluated using the osteosarcoma Saos-2 cells line. The in vitro bioactivity studies and the antibacterial tests against Gram-positive and Gram-negative bacteria revealed that the samples loaded with 2 mol% Nb2O5 had the highest bioactivity and greatest antibacterial effect. Overall, the results showed that the modified 45S5 bioactive glasses can be used as an antibacterial coating material for implants, with high bioactivity, being also non-cytotoxic to mammalian cells.

Tumor microenvironment-activated Nb2C quantum dots/lactate oxidase nanocatalyst mediates lactate consumption and macrophage repolarization for enhanced chemodynamic therapy.

Chemodynamic therapy (CDT), which takes advantages of CDT agents to selectively induce tumor cells apoptosis via Fenton or Fenton-like reactions, is considered to have great potential for tumor-specific treatment. However, the therapeutic outcome of CDT still faces the challenges of the lack of efficient CDT agents and insufficient supply of endogenous H2O2. Herein, to explore highly efficient CDT agents as well as increase the H2O2 content at tumor sites to enhance the efficiency of CDT, a red blood cell (RBC) membrane encapsulated Nb2C quantum dots/lactate oxidase (LOD) nanocatalyst (Nb2C QDs/LOD@RBC) was proposed. Nb2C quantum dots are quite prospective as efficient CDT agents in CDT application due to the intrinsic merits such as abundant active catalytic sites, satisfactory hydrophilicity, and good biocompatibility. The encapsulation of Nb2C QDs and LOD into RBC membrane was to prolong the in vivo circulation time of the nanocatalyst and increase its tumor sites accumulation. The accumulated Nb2C QDs/LOD@RBC nanocatalyst could efficiently convert the endogenous H2O2 into ·OH, while the overexpressed lactate could be catalyzed into H2O2 by LOD to replenish the depletion of H2O2. The cascaded reaction between Nb2C quantum dots and LOD eventually enhanced the CDT effect of Nb2C QDs/LOD@RBC nanocatalyst for tumors growth inhibition. Moreover, the consumption of lactate at tumor sites induced by Nb2C QDs/LOD@RBC nanocatalyst leads to the increased infiltration of antitumoral M1 tumor-associated macrophages, which alleviated the immunosuppression of the tumor microenvironment and further maximized the therapeutic outcome of CDT. Taken together, the Nb2C QDs/LOD@RBC nanocatalyst provides a promising paradigm for tumor inhibition via catalytic cascaded reaction between Nb2C quantum dots and LOD.

Bimetallic Aluminum- and Niobium-Doped MCM-41 for Efficient Conversion of Biomass-Derived 2-Methyltetrahydrofuran to Pentadienes.

The production of conjugated C4-C5 dienes from biomass can enable the sustainable synthesis of many important polymers and liquid fuels. Here, we report the first example of bimetallic (Nb, Al)-atomically doped mesoporous silica, denoted as AlNb-MCM-41, which affords quantitative conversion of 2-methyltetrahydrofuran (2-MTHF) to pentadienes with a high selectivity of 91 %. The incorporation of AlIII and NbV sites into the framework of AlNb-MCM-41 has effectively tuned the nature and distribution of Lewis and Brønsted acid sites within the structure. Operando X-ray absorption, diffuse reflectance infrared and solid-state NMR spectroscopy collectively reveal the molecular mechanism of the conversion of adsorbed 2-MTHF over AlNb-MCM-41. Specifically, the atomically-dispersed NbV sites play an important role in binding 2-MTHF to drive the conversion. Overall, this study highlights the potential of hetero-atomic mesoporous solids for the manufacture of renewable materials.

A Ti/Nb-functionalized COF material based on IMAC strategy for efficient separation of phosphopeptides and phosphorylated exosomes.

In this work, on the basis of an immobilized metal ion affinity chromatography enrichment strategy, a new kind of covalent organic framework (COF) material for enrichment of phosphorylated peptides and exosomes was successfully prepared in a facile method, and Ti4+ and Nb5+ were used as dual-functional ions (denoted as COF-S-S-COOH-Ti4+/Nb5+). With the advantage of unbiased enrichment towards phosphopeptides, COF-S-S-COOH-Ti4+/Nb5+ shows ultra-high selectivity (maximum molar ratio of ß-casein: BSA is 1:20,000) and low limit of detection (0.2 fmol). In addition, the material has an excellent phosphopeptide loading capacity (100 µg/mg) and reusability (at least seven times). Furthermore, applying the material to the actual sample, 4 phosphopeptides were selectively extracted from the serum of renal carcinoma patients. At the same time, exosomes with an intact structure in the serum of renal carcinoma patients were successfully isolated rapidly using this strategy. All experiments have shown that COF-S-S-COOH-Ti4+/Nb5+ exhibits exciting potential in practical applications.

Niobium Diselenide Nanosheets: An Emerging Biodegradable Nanoplatform for Efficient Cancer Phototheranostics in the NIR-II Window.

As a prominent class of 2D transition metal dichalcogenides (TMDCs), niobium diselenide nanosheets (NbSe2 NSs) have garnered tremendous interest on account of promising applications pertaining to optoelectronics and energy storage. Although NbSe2 NSs have many unique advantages such as inherent biocompatibility and broad absorption in the NIR region, their biomedical applications have rarely been reported, especially as therapeutic agents for the second near-infrared (NIR-II) range. Herein, a biodegradable nanotherapeutic platform consisting of NbSe2 NSs is designed and demonstrated for NIR-II light-triggered photothermal therapy. NbSe2 NSs synthesized by grinding and liquid exfoliation exhibit superior photothermal conversion efficiency (48.3%) and remarkable photothermal stability in the NIR-II region. In vitro assessment demonstrates that NbSe2 NSs have favorable photothermal cell ablation efficiency and biocompatibility. After intravenous injection in vivo, the NbSe2 NSs accumulate passively in tumor sites to facilitate fluorescence imaging and tumor ablation by NIR-II illumination. Furthermore, as a result of gradual degradation in the physiological environment, NbSe2 NSs can be excreted from the body to avoid potential toxicity caused by long-term retention in vivo. The results reveal a promising NIR-II light-triggered PTT strategy with the aid of NbSe2 NSs and the platform is expected to have large potential in cancer theranostics.

Hypoallergenic unicompartmental knee arthroplasty and return to sport: comparison between Oxidized Zirconium and Titanium Niobium Nitride.

BACKGROUND: The present study aims to compare the rate of return to sports in patients who underwent surgery for mobile-bearing UKA with either hypoallergenic TiNbN or with oxidized zirconium alloy implants. METHODS: The records of two consecutive cohorts for a total of 90 hypoallergenic implants were prospectively analysed. The first cohort consisted of 41 consecutive series of medial mobile-bearing hypoallergenic TiNbN UKA, whereas the second cohort consisted of 49 consecutive medial fixed-bearing hypoallergenic Uni Oxinium.The clinical evaluation involved evaluating each patient's University of California, Los Angeles (UCLA) activity scoresand the High-Activity Arthroplasty Score(HAAS). Each patient was clinically evaluated on the day before surgery (T0), then after a minimum follow-up period of 12 months (T1), and finally after 24 months (T2).   Results:The only pre-operative difference between the two groups involved pre-operative BMI with significantly higher BMI in TiNbN Group (p<0.001). Both groups reported significant improvement at each follow-up compared with the previous and also at the final follow up with respect to UCLA and HAAS (p<0.05), except for UCLA in TiNbN between T1 and T2(p>0.05). Moreover, BMI improved significantly at the final follow up, but only in TiNbN group (p<0.05). CONCLUSIONS: Both TiNbN and Oxinium UKA procedures enabled patients to return to an acceptable level of sports activity with excellent radiographic outcomes after the final follow up regardless of the age, gender, BMI, and bearing type.

Hydrothermal Synthesis of ß-Nb2ZnO6 Nanoparticles for Photocatalytic Degradation of Methyl Orange and Cytotoxicity Study.

ß-Nb2ZnO6 nanoparticles were synthesized by a hydrothermal process and calcined at two temperatures, 500 °C and 700 °C, and assigned as A and B, respectively. X-ray diffraction, together with transmission electron microscopy, revealed that the ß-Nb2ZnO6 nanoparticles calcined at 700 °C (B) were more crystalline than the ß-Nb2ZnO6 calcined at 500 °C (A) with both types of nanoparticles having an average size of approximately 100 nm. The physiochemical, photocatalytic, and cytotoxic activities of both types of ß-Nb2ZnO6 nanoparticles (A and B) were examined. Interestingly, the photodegradation of methyl orange, used as a standard for environmental pollutants, was faster in the presence of the ß-Nb2ZnO6 nanoparticles calcined at 500 °C (A) than in the presence of those calcined at 700 °C (B). Moreover, the cytotoxicity was evaluated against different types of cancer cells and the results indicated that both types of ß-Nb2ZnO6 nanoparticles (A and B) exhibited high cytotoxicity against MCF-7 and HCT116 cells but low cytotoxicity against HeLa cells after 24 and 48 h of treatment. Overall, both products expressed similar EC50 values on tested cell lines and high cytotoxicity after 72 h of treatment. As a photocatalyst, ß-Nb2ZnO6 nanoparticles (A) could be utilized in different applications including the purification of the environment and water from specific pollutants. Further biological studies are required to determine the other potential impacts of utilizing ß-Nb2ZnO6 nanoparticles in the biomedical application field.

Release behavior and mechanism of uranium and thorium from Ta-Nb tailings under simulated rainfall in Jiangxi Province, China.

Tantalum-niobium ore belongs to associated radioactive ore, which is accompanied by a certain amount of radioactive uranium and thorium. The remaining slag is enriched with a large number of radionuclides; after weathering, natural rainfall, and surface water scouring, radioactive elements such as uranium, thorium, and some heavy metal elements are exposed or washed into the soil, which poses a threat to the ecological environment and human health. In this study, for characterization analysis during, before, and after leaching, dynamic simulation experiment was carried out on a Ta-Nb slag sample in Jiangxi, China. From SEM analysis, the soluble substances adsorbed on the slag surface dissolve into the solution after leaching in simulated rainfall, and the remained slag becomes smooth with different particle sizes. The XRD diffraction analysis of the sample showed that after leaching in simulated rainfall, the existing forms of elements are different. pH of the leachate of Ta-Nb slag is 1.79; Ta-Nb slag contains many rare metal elements, nonmetal elements, radioactive elements, and some salt compounds; and the content of thorium is higher than that of uranium by EDS analysis. The release of uranium and thorium is obviously affected by the amount of leachate and pH. Under the lower pH of leaching solution, the release of uranium and thorium is more effective. The results of Fick diffusion theory and Elovich equation show that the release and migration mode of uranium and thorium in Ta-Nb slag are mainly surface elution; under acidic conditions, the release and migration of uranium and thorium are faster. This study provides basic data and scientific information for solving the key problems of pollution control of associated radioactive waste in environmental protection.

Neuron Compatibility and Antioxidant Activity of Barium Titanate and Lithium Niobate Nanoparticles.

The biocompatibility and the antioxidant activity of barium titanate (BaTiO3) and lithium niobate (LiNbO3) were investigated on a neuronal cell line, the PC12, to explore the possibility of using piezoelectric nanoparticles in the treatment of inner ear diseases, avoiding damage to neurons, the most delicate and sensitive human cells. The cytocompatibility of the compounds was verified by analysing cell viability, cell morphology, apoptotic markers, oxidative stress and neurite outgrowth. The results showed that BaTiO3 and LiNbO3 nanoparticles do not affect the viability, morphological features, cytochrome c distribution and production of reactive oxygen species (ROS) by PC12 cells, and stimulate neurite branching. These data suggest the biocompatibility of BaTiO3 and LiNbO3 nanoparticles, and that they could be suitable candidates to improve the efficiency of new implantable hearing devices without damaging the neuronal cells.

Biocompatibility and corrosion evaluation of niobium oxide coated AZ31B alloy for biodegradable implants.

Biodegradable magnesium (Mg) based implants have considerable interest in the biomedical field as their use nullifies the necessity for implant removal surgery and avoids the long-standing adverse reaction of permanent bioimplants. The degradation resistance and biocompatibility of the Mg alloys can be improved by coating them with a suitable thin film. Here, thin films of niobium and niobium oxide were developed on the AZ31B Mg alloy by sputtering technique and their biocompatibility and corrosion resistance was examined. X-ray diffraction (XRD) and Transmission electron microscope (TEM) techniques confirmed the crystallinity of the thin films. Subsequently, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques were employed to evaluate the morphology and chemical composition of the thin film surfaces, respectively. Thin-film coated Mg alloys revealed good corrosion resistance compared to their uncoated bare counterparts in simulated body fluid (SBF). The contact angle study was performed on the coated specimens to investigate their wettability which revealed their hydrophobic character. The cell viability studies on thin-film coated specimens exhibited significant cell proliferation, and cell morphological studies showed good cell attachment and growth. The in vitro MTT assay on mouse osteoblast precursor cells (MC3T3-E1) indicated that the Nb-based coatings are cytocompatible and promote cell proliferation.

Microbial acoustic sensor test-system based on a piezoelectric resonator with a lateral electric field for kanamycin detection in liquid.

A microbial test-system for real-time determination of low/residual concentrations of kanamycin in a liquid without the need for special labels is presented. The main element of the system was a piezoelectric resonator excited by a lateral electric field based on an X-cut lithium niobate plate 0.5 mm thick with two rectangular electrodes on one side. On the other side of the resonator, there was a 1.5 ml liquid container. As a sensory element we used Escherichia coli B-878 microbial cells, which are sensitive to kanamycin. For measurement 1 ml of this cells suspension was placed in a liquid container and then the test liquid in the amount of 2 µl containing kanamycin was added. The change in the real part of the electrical impedance of the resonator before and after the test liquid addition was used as an analytical signal which indicated the presence of kanamycin. The lower limit of determination of kanamycin turned out to be 1.0 µg/ml with an analysis time of 10 min. The test-system allows to detect kanamycin in the presence of such antibiotic as ampicillin and polymixin.

A molecularly imprinted electrochemical biosensor based on hierarchical Ti2Nb10O29 (TNO) for glucose detection.

A novel molecularly imprinted electrochemical biosensor for glucose detection is reported based on a hierarchical N-rich carbon conductive-coated TNO structure (TNO@NC). Firstly, TNO@NC was fabricated by a novel polypyrrole-chemical vapor deposition (PPy-CVD) method with minimal waste generation. Afterward, the electrode modification with TNO@NC was performed by dropping TNO@NC particles on glassy carbon electrode surfaces by infrared heat lamp. Finally, the glucose-imprinted electrochemical biosensor was developed in presence of 75.0 mM pyrrole and 25.0 mM glucose in a potential range from + 0.20 to + 1.20 V versus Ag/AgCl via cyclic voltammetry (CV). The physicochemical and electrochemical characterizations of the fabricated molecularly imprinted biosensor was conducted by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) method, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and CV techniques. The findings demonstrated that selective, sensitive, and stable electrochemical signals were proportional to different glucose concentrations, and the sensitivity of molecularly imprinted electrochemical biosensor for glucose detection was estimated to be 18.93 µA µM-1 cm-2 (R2 = 0.99) at + 0.30 V with the limit of detection (LOD) of 1.0 × 10-6 M. Hence, it can be speculated that the fabricated glucose-imprinted biosensor may be used in a multitude of areas, including public health and food quality.

Low Mg content on Ti-Nb-Sn alloy when in contact with eBMMSCs promotes improvement of its biological functions.

Magnesium is a metal used in the composition of titanium alloys and imparts porosity. Due to its osteoconductive, biocompatible and biodegradable characteristics, its application in the development of biomedical materials has become attractive. This study aimed to evaluate the influence of magnesium present in porous Ti-Nb-Sn alloys, which have a low elastic modulus in adhesive, osteogenic properties and the amount of reactive intracellular oxygen species released in mesenchymal stem cells derived from bone marrow equine bone (eBMMSCs). Mechanical properties of the alloy, such as hardness, compressive strength and elastic modulus, were analyzed, as well as surface morphological characteristics through scanning electron microscopy. The evaluation of magnesium ion release was performed by atomic force spectroscopy. The biological characteristics of the alloy, when in contact with the alloy surface and with the culture medium conditioned with the alloy, were studied by SEM and optical microscopy. Confirmation of osteogenic differentiation by alizarin red and detection of ROS using a Muse® Oxidative Stress Kit based on dihydroetide (DHE). The alloy showed an elastic modulus close to cortical bone values. The hardness was close to commercial Ti grade 2, and the compressive strength was greater than the value of cortical bone. The eBMMSCs adhered to the surface of the alloy during the experimental time. Osteogenic differentiation was observed with the treatment of eBMMMSCs with conditioned medium. The eBMMSCs treated with conditioned medium decreased ROS production, indicating a possible antioxidant defense potential of magnesium release.

Mid-term results of a new femoral prosthesis using Ti-Nb-Sn alloy with low Young's modulus.

BACKGROUND: This study was performed to investigate the mid-term results of Ti-Nb-Sn (TNS) alloy stem with a low Young's modulus. METHODS: This study was a multicenter prospective cohort study. A total of 40 primary total hip arthroplasties performed between April 2016 and September 2017 was enrolled in this study. With the unique functional gradient properties by heating treatment, the strength of the proximal portion was enhanced, while the distal portion maintained a low Young's modulus. The surgeries were performed through the posterolateral approach using the TNS alloy stems. Radiographs were taken from immediately after surgeries until 3 years, and stress shielding and subsidence of the stems were evaluated. The incidences of the stem breakage were also assessed. Clinical assessments were performed using Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores. RESULTS: Among the 40 enrolled patients, 36 patients were female and 4 were male. At 3 years after surgery, there were no radiologic signs of loosening, subsidence, or breakage of the stem. Stress shielding was observed in 26 hips (65%). Of 26 hips, 16 hips (40%) were grade 1 and 10 hips (25%) were grade 2. There was no advanced stress shielding. The JOA and JHEQ scores significantly improved compared with the preoperative scores. CONCLUSION: The current study using a new TNS alloy femoral stem showed good clinical outcomes at 3-year follow-up. Radiologically, there was no loosening or subsidence of the stem. The mild stress shielding was observed in 65% of patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN21241251 . The date of registration was October 26, 2021. Retrospectively registered.

Functionalized 2D Nb2C nanosheets for primary and recurrent cancer photothermal/immune-therapy in the NIR-II biowindow.

Near-infrared-II (NIR-II) cancer photothermal therapy (PTT) has become more and more attractive as the NIR-II light shows a higher tissue penetrating depth, which leads to better anti-cancer effects. Recently, the members of the MXene family have been reported as NIR-II photothermal agents, possessing a high specific surface area and a fascinating light-to-heat conversion rate at the same time. Herein, we reported a combination of NIR-II photothermal therapy and immune therapy based on the MXene family member niobium carbide (Nb2C). First, Nb2C nanosheets (NSs) under 50 nm were prepared. They showed a high photothermal conversion efficiency under a 1064-nm laser, and the NIR-II light showed a deeper tissue penetration depth. Then, a nanoplatform with high R837 stability and a high loading rate was obtained after modification with a polydopamine (PDA) layer on the surface of Nb2C. With the R837 modification, the percentage of mature dendritic cells (DCs) increased and the immune response enhanced, compared with the immune response caused by PTT only. Finally, a red blood cell (RBC) membrane was applied as a coat over the nanoplatform in order to avoid excessive blood clearance. During in vivo experiments, blood circulation of Nb2C@PDA-R837@RBC nanoparticles (NPs) was prolonged, and all primary tumors were eliminated. Secondary tumors were also inhibited effectively due to the strengthened immune response, proving that Nb2C@PDA-R837@RBC NPs could inhibit tumor recurrence. All the results above indicated Nb2C@PDA-R837@RBC NPs as a potential RBC camouflaged nanoplatform for the combination of effective PTT and immune therapy towards tumor treatment.

Dual-responsive ultrathin 1T-phase niobium telluride nanosheet-based delivery systems for enhanced chemo-photothermal therapy.

1T-phase niobium telluride (NbTe2) nanosheets are becoming increasingly important in emerging fields, such as spintronics, sensors and magneto-optoelectronics, due to their excellent physical and chemical properties. However, exploration on their biomedical applications are limited. Herein, ultrathin 1T-phase NbTe2 single-crystalline nanosheets with excellent photothermal performance, high drug-loading rate, near-infrared (NIR) light/acidic pH-triggered drug release, and low toxicity were developed for potentiated photothermal therapy. Importantly, they showed excellent biocompatibility in vivo and in vitro. NbTe2 nanosheets loaded with integrated stress response inhibitors (ISRIB) could achieve chemo-photothermal therapy of tumors through the ATF4-ASNS signaling axis. Ultrathin 1T-phase NbTe2 single-crystalline nanosheets with unique photothermal properties, drug loading rate and safety provide dramatic possibilities in biomedical applications, such as tissue imaging, photothermal therapeutics and pharmaceutics.