Expression of concern: Surface modification engineering of two-dimensional titanium carbide for efficient synergistic multitherapy of breast cancer.

Expression of concern for 'Surface modification engineering of two-dimensional titanium carbide for efficient synergistic multitherapy of breast cancer' by Lei Bai et al., J. Mater. Chem. B, 2020, 8, 6402-6417, https://doi.org/10.1039/D0TB01084G.

Tumor microenvironment responsive chitosan-coated W-doped MoOx biodegradable composite nanomaterials for photothermal/chemodynamic synergistic therapy.

Chemodynamic therapy (CDT), an approach that eradicates tumor cells through the catalysis of hydrogen peroxide (H2O2) into highly toxic hydroxyl radicals (·OH), possesses distinct advantages in tumor specificity and minimal side effects. However, CDT's therapeutic efficacy is currently hampered by the low production efficiency of ·OH. To address this limitation, this study introduces a water-soluble chitosan-coated W-doped MoOx (WMoOx/CS) designed for the combined application of photothermal therapy (PTT) combined with CDT. The W-doped MoOx (WMoOx) was synthesized in one step by the hydrothermal method, and its surface was modified by water-soluble chitosan (carboxylated chitosan, CS) to enhance its biocompatibility. WMoOx boasts a high near-infrared photothermal conversion efficiency of 52.66 %, efficiently transducing near-infrared radiation into heat. Moreover, the Mo4+/Mo5+ and W5+ ions in WMoOx catalyze H2O2 to produce ·OH for CDT, and the Mo5+/Mo6+ and W6+ ions in WMoOx reduce intracellular glutathione levels and prevent the scavenging of ·OH by glutathione. Crucially, the combination of WMoOx/CS and near-infrared light irradiation demonstrates promising synergistic antitumor effects in both in vitro and in vivo models, highlighting its potential for the combined application of PTT and CDT.

A simple, rapid and sensitive sandwich immunoassay based on poly(N-isopropylacrylamide) for the detection of alpha-fetoprotein.

Alpha-fetoprotein (AFP), as a tumor marker, plays a vital role in the diagnosis of liver cancer. In this work, a novel sandwich immunoassay based on a thermosensitive polymer, poly(N-isopropylacrylamide) (PNIPAM), was developed for the detection of AFP. This immunoassay could realize one-step rapid reaction within 1 h, and facilitate the separation of the target molecules by incorporating PNIPAM. In this method, a conjugate of PNIPAM and capture antibody (Ab1) was successfully synthesized as a capture probe and the synthetic method of PNIPAM-Ab1 was simple, while the detection antibody (Ab2) was labeled with fluorescein isothiocyanate (FITC) to form a fluorescent detection probe. By employing a sandwich immunoassay, the method achieved quantitative determination of AFP, exhibiting a wide linear range from 5 ng/mL to 200 ng/mL and a low detection limit of 2.44 ng/mL. Furthermore, it was successfully applied to the analysis of spiked human serum samples and the screening of patients with hepatic diseases in clinical samples, indicating its potential application prospect in the diagnosis of liver cancer.

Endothelin receptors in augmented vasoconstrictor responses to endothelin-1 in chronic intermittent hypoxia.

Chronic intermittent hypoxia (CIH) contributes to the development of cardiovascular diseases in patients with obstructive sleep apnoea. Many studies have shown an association between increased circulating endothelin (ET)-1 levels and CIH. The aim of the present study was to determine the role of ET receptors in altered aortic function in an animal model of CIH. Rats were subjected to CIH (Fi o2 9% for 1 min, repeated every 2 min for 8 h/day, 7 days/week) for 3 weeks. After 3 weeks, the rats were killed and their aortas retrieved for use in in vitro experiments (isometric force measurement), histological analysis, immunohistochemistry and western blotting. Aortas from rats subjected to CIH exhibited marked endothelial dysfunction and increased responsiveness to ET-1. Furthermore, CIH induced increased ET-1 and ETA receptor expression, whereas ETB receptor expression was decreased. Aortic contractile responses to ET-1 were inhibited by the ETA and ETB receptor antagonists BQ-123 and BQ-788, respectively. Acetylcholine-induced relaxation responses were significantly attenuated in aortas from rats subjected to CIH, whereas CIH had no significant effect on aortic responses to sodium nitroprusside. The results of the present study suggest that increased expression of ETA receptors, which mediate a potent vasoconstrictor response, plays an important role in the pathogenesis of CIH. In addition, decreased endothelial ETB receptor expression, which is associated with the functional decline of endothelium-dependent vasodilation, also contributes to the pathogenesis of CIH. It appears that the ETB receptor-induced buffering of ET-1 responsiveness is mediated via a nitric oxide-dependent mechanism.

Dual-Color Fluorescent Hydrogel Microspheres Combined with Smartphones for Visual Detection of Lactate.

Since it is difficult for human eyes to distinguish between two identical colors with only <15% variation in brightness, mono-color fluorescent hydrogel microspheres have some limitations in the detection of lactate. Herein, we prepared novel dual-color fluorescent hydrogel microspheres, which can achieve hue transformation. Microspheres were prepared by introducing a fluorescent nanoparticle as the reference signal while CdTe QDs were used as the response signal. We used smartphones with image processing software to collect and analyze data. In this way, the signal of lactate was converted to RGB (red, green, and blue) values, which can be quantitatively read. Within 10 to 1500 µM, the R/G values of the microspheres had a linear relationship with the logarithm of the lactate concentration. Moreover, color cards for lactate detection were prepared, from which the color change and concentration of lactate could be easily read by the naked eye. It is worth mentioning that this method was successfully applied to screen patients with hyperlactatemia.

Two-Stage Targeted Bismuthene-Based Composite Nanosystem for Multimodal Imaging Guided Enhanced Hyperthermia and Inhibition of Tumor Recurrence.

A key challenge for nanomedicines in clinical application is to reduce the dose while achieving excellent efficacy, which has attracted extensive attention in dose toxicity and potential risks. It is thus necessary to reasonably design nanomedicine with high-efficiency targeting and accumulation. Here, we designed and synthesized a tetragonal bismuthene-based "all-in-one" composite nanosystem (TPP-Bi@PDA@CP) with two-stage targeting, multimodal imaging, photothermal therapy, and immune enhancement functions. Through the elaborate design of its structure, the composite nanosystem possesses multiple properties including (i) two-stage targeting function of hepatoma cells and mitochondria [the aggregation at the tumor site is 2.63-fold higher than that of traditional enhanced permeability and retention (EPR) effect]; (ii) computed tomography (CT) contrast-enhancement efficiency as high as ∼51.8 HU mL mg-1 (3.16-fold that of the clinically available iopromide); (iii) ultrahigh photothermal conversion efficiency (52.3%, 808 nm), promising photothermal therapy (PTT), and high-contrast infrared thermal (IRT)/photoacoustic (PA) imaging of tumor; (iv) benefitting from the two-stage targeting function and excellent photothermal conversion ability, the dose used in this strategy is one of the lowest doses in hyperthermia (the inhibition rate of tumor cells was 50% at a dose of 15 µg mL-1 and 75% at a dose of 25 µg mL-1); (v) the compound polysaccharide (CP) shell with hepatoma cell targeting and immune enhancement functions effectively inhibited the recurrence of tumor. Therefore, our work reduces the dose toxicity and potential risk of nanomedicines and highlights the great potential as an all-in-one theranostic nanoplatform for two-stage targeting, integrated diagnostic imaging, photothermal therapy, and inhibition of tumor recurrence.

A PdMo bimetallene with precise wavelength adjustment and catalysis for synergistic photothermal ablation and hydrogen therapy of cancer at different depths.

By delivering the idea of green and safe hydrogen energy and novel photothermal therapy to the biomedical field, engineering of therapeutic nanomaterials for treatment of major diseases (such as cancer) holds great significance. In this work, a novel PdMo bimetallene was synthesized by a solvothermal reduction method, and it was explored and applied in the field of anti-tumor therapy for the first time. The absorption peak of the PdMo bimetallene can be precisely adjusted in the NIR biological window (700-1350 nm) only by changing the synthesis time. At the same time, it also shows strong light absorption and high photothermal conversion efficiency. Specifically, the photothermal conversion efficiencies at 808 nm, 980 nm and 1064 nm are 43.1%, 51.7% and 69.15%, respectively. Surprisingly, a PdMo bimetallene is an efficient catalyst, which can effectively promote hydrogen production from the hydrolysis of ammonia borane (AB) under acidic and photothermal conditions. Benefitting from these excellent properties, a multifunctional composite nano therapeutic agent (PdMo@AB@HA) was developed via layer-by-layer surface modification with AB and hyaluronic acid (HA). In this way, the synergistic PTT/hydrogen therapy of PdMo@AB@HA composite nanosheets in the NIR-I and NIR-II windows (808 nm, 980 nm, and 1064 nm) on mouse tumor xenografts of different depths was realized. Furthermore, the controlled release of hydrogen, targeted endocytosis, efficient eradication of tumors of different depths and high biosafety were systematically proved in vitro and in vivo. This work not only provides a novel and efficient theranostic nanoplatform for efficient cancer theranostics, but also provides a new strategy for the development of safe and efficient new anti-tumor therapies.

A Review on Electrospun Nanofibers Based Advanced Applications: From Health Care to Energy Devices.

Electrospun nanofibers have been exploited in multidisciplinary fields with numerous applications for decades. Owing to their interconnected ultrafine fibrous structure, high surface-to-volume ratio, tortuosity, permeability, and miniaturization ability along with the benefits of their lightweight, porous nanofibrous structure, they have been extensively utilized in various research fields for decades. Electrospun nanofiber technologies have paved unprecedented advancements with new innovations and discoveries in several fields of application including energy devices and biomedical and environmental appliances. This review article focused on providing a comprehensive overview related to the recent advancements in health care and energy devices while emphasizing on the importance and uniqueness of utilizing nanofibers. A brief description regarding the effect of electrospinning techniques, setup modifications, and parameters optimization on the nanofiber morphology was also provided. The article is concluded with a short discussion on current research challenges and future perspectives.

A simple MWCNTs@paper biosensor for CA19-9 detection and its long-term preservation by vacuum freeze drying.

This paper introduces a cheap simple MWCNTs@paper biosensor for the detection of CA19-9, which is a biomarker of pancreatic cancer. By adding the CA19-9 antibody to the surface of MWCNTs which are deposited on the microporous filter paper, the correlation between the concentration of CA19-9 and resistance of biosensor element was linear due to the site-specific binding of antigen and antibody. The detection range is wide (0 U/mL-at least 1000 U/mL), and even in the low concentration of CA19-9, the linearity remains satisfying. Based on this property, it could be used for the detection of early-stage pancreatic cancer. Besides, this research originally introduces a vacuum freeze-drying method for the long-term preservation of biosensor, prolonging its storage time from 3 h to at least 7 days, which signifcantly promoted its value in practical application. One piece of the MWCNTs@paper biosensor only cost $2 (about 30 times cheaper than ELISA) approximately, and the detection speed is satisfying (2 h, 12 times faster than ELISA), which will possibly increase its opportunity of mass production and clinical practice.

Surface modification engineering of two-dimensional titanium carbide for efficient synergistic multitherapy of breast cancer.

Cancer is a leading cause of human mortality. Given that it is difficult for conventional therapeutic approaches to effectively eradicate tumors and inhibit their recurrence and metastasis, new therapeutic strategies for solving this problem are urgently needed. In this work, we report the development of a two-dimensional titanium carbide nanocomposite drug delivery system. The system can be used for the synergistic treatment of tumors through photothermal/photodynamic/chemotherapy and can also inhibit tumor recurrence and metastasis by activating the immune system. A surface modification engineering strategy has been elaborately designed to realize the multifunctionalization of an MXene, Ti3C2. In this strategy, the nanocomposite drug delivery system (Ti3C2@Met@CP) was established via layer by layer adsorption of metformin (Met) and compound polysaccharide (CP) on the surface of Ti3C2 nanosheets. Among these materials, the synthesized (AlOH)4--functionalized Ti3C2 nanosheets possess strong near-infrared absorption (extinction coefficient of 36.2 L g-1 cm-1), high photothermal conversion efficiency (∼59.6%) and effective singlet oxygen generation (1O2). Compound polysaccharide (CP) is a new immunomodulator formed by mixing lentinan, pachymaran and tremella polysaccharides in optimal proportions. Especially, the decoration of CP onto the Ti3C2 nanosheets endows Ti3C2 with a well-defined shell, improves its tumor site aggregation and biocompatibility, and activates the host's immune functions. The synergistic eradication and inhibition of tumor recurrence and metastasis have been systematically evaluated by in vivo and in vitro experiments.

Lentinan in-situ coated tungsten oxide nanorods as a nanotherapeutic agent for low power density photothermal cancer therapy.

Development of high photothermal performance and biocompatible nanotherapeutic agents is of great importance for photothermal cancer treatment. In this paper, we have developed lentinan decorated tungsten oxide nanorods (W18O49@LTN NRs) via a mild one-step solvothermal route. Owing to the numerous surface hydroxyl groups of polymer chains, the presence of lentinan layer in the surface of W18O49 NRs lead to good biocompatibility. The lentinan layer also affects the crystal structure of W18O49 and improves near-infrared absorption (~1.7 × 109 M-1 cm-1 at 980 nm), which is two orders of higher than previously reported PEGylated W18O49 nanowires. Even under near-infrared (NIR) laser irradiation at a very low power density of 0.4 W/cm2, the temperature of W18O49@LTN NRs aqueous dispersion (125 µg/mL) could increase by 15.1 °C. The photothermal conversion efficiency of W18O49@LTN NRs reaches 33.86%, which is higher than previously reported WO3-x hierarchical nanostructures (28.1%). Importantly, when cancer cells were treated with W18O49@LTN NRs (200 µg/mL) and 980 nm laser (0.4 W/cm2), a significant photo-induced cell killing behavior was observed. This work demonstrates that W18O49@LTN NRs have the potential for precise cancer treatment.

Enrichment of large-diameter semiconducting single-walled carbon nanotubes by a mixed-extractor strategy.

In this work, we report a new mixed-extractor strategy to improve the sorting yield of large-diameter semiconducting single-walled carbon nanotubes (s-SWCNTs) with high purity. In the new mixed-extractor strategy, two kinds of conjugated polymers with different rigidity, poly(9,9-n-dihexyl-2,7-fluorene-alt-9-phenyl-3,6-carbazole) (PDFP) and poly(9,9-dioctylfluorene-alt-benzothiadiazole) (P8BT), are used to sort large-diameter s-SWCNTs through two simple sonication processes. To our surprise, although PDFP itself shows no selectivity toward s-SWCNTs, it can greatly enhance the sorting yield of P8BT. Using the PDFP/P8BT mixed-extractor method, the yield of sorted s-SWCNTs has been enhanced by 5 times with a purity above 99 % in comparison to that using P8BT single-extractor method. In addition, the photoluminescence (PL) excitation maps shows that the PDFP/P8BT mixed-extractor system not only enhances the sorting yield substantially, but also tends to be enrichment of (15,4) SWCNTs with the diameter of 1.36 nm.