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The “partial matching” between upconversion nanoparticle (UCNP) emission and absorption by photosensitizers (PSs) often leads to a theoretically reduced therapeutic efficiency in UC-based photodynamic therapy (PDT) strategies in which the chosen PSs have limited capabilities and are unable to utilize all the near-infrared-upconverted light. In this study, needle-like SnWO 4 nanocrystals (SWs) with a broad UV–vis absorption region were synthesized to solve the problem. After covalent conjugation with UCNPs, all the UCNP-emitted light was effectively absorbed by SWs, triggering the type-I PDT process to activate ROS maxima. The unique nanostructure of the as-formed UCNP-SnWO 4 nanohybrids (USWs) also enhanced the receiving light intensities of SW, which further boosted the antitumor efficacy. Meanwhile, the strong X-ray attenuation capacity of both tungsten and tin elements qualified the USWs as excellent radio-sensitizers for radiotherapy (RT) enhancement, which played a complementary role with PDT treatment because PDT-mediated induction arrested the cells in the G0-G1 cell cycle phase, and RT was more damaging toward cells in the G2/M phase. The remarkably enhanced UC-PDT/RT efficiency of USWs was next validated in vitro and in vivo, and the combined NIR light and ionizing irradiation treatment completely suppressed tumor growth, revealing its great potential as an efficient anticancer therapeutic agent against solid tumors. [ABSTRACT FROM AUTHOR]

As a distinct feature of Alzheimer's disease (AD), the presence of excess metal ions in the brain is most probably one of the main causative factors for the aggregation of β-Amyloid (Aβ) proteins. The design of nanoprobes for detection and control of ion concentrations will be of great importance in predicting the progression of AD and simultaneously providing effective treatments. Herein, we report the design and synthesis of a novel yet smart nanoprobe that can sensitively detect the Cu 2+ concentration and concurrently capture Cu 2+ both in vitro and in vivo . The designed nanoprobe (UCHQ) combines two main components: upconversion nanoparticles (UCNPs) used for the detection and upconversion luminescence (UCL) imaging of Cu 2+ upon 980 nm exposure and the chelator 8-hydroxyquinoline-2-carboxylic acid (HQC) used for chelating Cu 2+ and AD therapy. The results show that the emission intensity of UCHQ is highly dependent on the Cu 2+ concentrations due to the luminescence resonance energy transfer (LRET) from UCNPs to HQC-bonded Cu 2+ . Fascinatingly, the as-constructed UCHQs could be used for UCL imaging of Aβ both in cells and AD mice. Most importantly, UCHQs could not only inhibit the Aβ aggregation-induced apoptosis via capturing overmuch Cu 2+ but also accelerate the nontoxic structural transformation of Aβ. [ABSTRACT FROM AUTHOR]

How to timely identify the food quality through a low-cost, easy operation, and high-throughput way is a milestone protects for food industry, especially in resource-limited area. Nanosensors by integrating with biomolecules (such as antibodies and aptamers) have emerged substitutes for the standard equipment analysis in the large-scale screening. However, the expensive cost of biomolecules, the "lock-key" combination unable to solve some problems (such as food freshness), and emerging food risks have strictly their development in food industry. Additionally, nanosensors without biomolecules are easily suffered from the non-specific interference, making the detection results unreliable. Therefore, some studies have concentrated on the sensor array by using nanomaterials as receptors to solve abovementioned problems, which is based on the multiple signal responses to generate the distinctive fingerprint for each analyte. This review comprehensively discussed the machine learning-assisted nanosensor arrays for the efficiently high-throughput food detection analysis, which mainly concludes candidates for nanosensor arrays, commonly used machine learning algorithms, and the application in food applications (such as foodborne hazards, food components, food freshness, food origin, and food adulteration). Additionally, we have proposed the challenges and prospects of machine learning-assisted nanosensor arrays in food applications to bridge the gap of current development bottleneck. Therefore, machine learning-assisted nanosensor arrays for the efficiently high-throughput detection analysis in food industry are proposed. • Nanoreceptors to develop nanosensor arrays for high-throughput identification are comprehensively discussed. • Machine learning algorithms commonly used in Nanosensor arrays for high-throughput identification are critically presented. • The emerging applications of machine learning-assisted nanosensor arrays in food applications are reviewed. • Current challenges and future opportunities of machine learning-assisted nanosensor arrays in food industry are discussed. [ABSTRACT FROM AUTHOR]

• Some chemical dyes were studied to improve the catalytic activity of HRP. • Chemical staining strategy for enhancing performance of ELISA was firstly proposed. • Sensitivity and detection range of proposed ELISA were enhanced simultaneously. Exploring a novel strategy for strengthening the catalytic activity of enzyme facilitates the development of a sensitive enzyme-linked immunosorbent assay (ELISA). Herein, a chemical staining (CS) strategy was firstly discovered to possess the ability to directly improve the catalytic activity of horseradish peroxidase. Based on this discovery, coomassie brilliant blue was introduced into ELISA to establish a CS enhanced ELISA (CS-ELISA) to detect clenbuterol (CL) by simply staining monoclonal antibodies. Satisfactorily, the most important analytical parameters of CS-ELISA, including sensitivity (0.074 ng mL−1) and linear range (0.2–2 ng mL−1) were all improving 2-folds compared with conventional ELISA. Moreover, the CS-ELISA shows good applicability in the detection of CL in pork tenderloin samples. The proposed CS-ELISA shows various advantages, such as cost-effective, easily accessible, enhanced catalytic activity of enzyme, higher sensitivity, and broader linear range, providing a new insight into enhanced ELISA for food safety. [ABSTRACT FROM AUTHOR]

Exploring a nanozyme as a nanocarrier for the enzyme-labeled antibodies (ELA) in the enzyme-linked immunosorbent assay (ELISA) is beneficial in improving the analytical performance of ELISA. Herein, a white Fe-based coordination polymer nanozyme (FCPN) was fabricated as a nanocarrier for the ELA to improve the catalytic activity and relieve the color interference of nanoprobes in ELISA. The proposed enhanced catalytic immunoassay (ECI) exhibits high analytical performance for the quantification of clenbuterol (CLL) in the detection range of 0.09–10 ng mL−1 with a limit of detection (LOD) as low as 0.09 ng mL−1, improving the detection sensitivity nearly 3.5 times compared with the conventional ELISA. Meanwhile, the usage of anti-CLL monoclonal antibodies in this proposed ECI was economizes by 6.7 times and the detection sensitivity was increased by nearly 4.5 times compared with our previous research. In addition, the detection sensitivity of the ECI using a white nanozyme as a nanocarrier is 2.3 times higher than using a blue Cu-based metal organic framework (Cu-MOF) nanozyme. Meanwhile, the applicability of the proposed ECI was successfully demonstrated by the detection of CLL in pork meat and pork liver with recoveries ranging from 92.51% to 110.16%. • Improved sensitivity and a wider detection range are both obtained in this assay. • The white FCPN nanozymes have higher analytical performances over blue Cu-MOF. • This assay economizes the usage of antibodies compared with our previous work. [ABSTRACT FROM AUTHOR]

Hypoxia, as an inevitable characteristic of solid tumors, has been regarded as a noticeably causative factor to therapeutic resistance and metastatic variants. Exploring novel theranostics to realize the accurate diagnosis of hypoxia and the simultaneous implementation of effective therapy is a promising prospect for the successful treatment of tumors. In the present study, we designed and synthesized a multifunctional rattle-structured nanotheranostic, with the inner core coated by hollow mesoporous silica for chemical drug Doxorubicin (DOX) storage and hypoxia-sensitive MnO 2  enrichment. In various acidic micro-environments caused by hypoxia, MnO 2 nanosheets could be degraded into manganese ions (Mn 2+ ), which were chelated by the modified Tetraxetanum (DOTA) ligands for real-time T 1 -magnetic resonance imaging (T 1 -MRI), with on-demand DOX release to realize both normoxia and hypoxia-sensitive chemotherapy by overcoming hypoxia. Nanotheranostics integrating hypoxia-driven T 1 -MRI with synergetic chemotherapy have tremendous potential in the intelligent diagnosis, personalized treatment and excellent prognosis of solid tumors in the future. [ABSTRACT FROM AUTHOR]

Colon cancer (CC) is one of the most common intestinal malignancies and is difficult to detect in its early stage by magnetic resonance imaging (MRI) with currently used contrast agents (CAs). The development of targeted CAs contributes to the early diagnosis of CC and thereby enables early intervention and timely therapy. Considering the outstanding performance of upconversion nanoprobes (UCNPs) in high-performance MR and fluorescence imaging, a new type of nanoprobes with considerably enhanced imaging performance is developed herein. Carcinoembryonic antigen (CEA) antibody is conjugated onto the surface of UCNPs to achieve the targeted imaging of early CC tumors, which overexpress CEA. Both toxicity tests and histological/hematological examinations demonstrate the excellent biocompatibility of these CC-targeting nanoprobes, which possess great potential for clinical application in the early diagnosis of CC. [ABSTRACT FROM AUTHOR]

CT angiography (CTA) and CT perfusion (CTP) imaging can play important roles in the workup of acute ischemic stroke. However, these techniques are hindered by the large amounts of contrast agents (CAs) required, high doses of X-ray radiation exposure, and nephrotoxicity of the clinical used iodinated CAs. To address these problems, we synthesized and validated a novel class of CT CAs, PEGylated BaHoF 5 nanoparticles (NPs), for CTA and CTP imaging, which can greatly enhance the diagnostic sensitivity and accuracy of ischemic stroke. These agents have unique advantages over conventional iodinated CT agents, including much lower dosage required, major metabolism through liver and better imaging efficiency at different voltages. Once translated, these PEGylated BaHoF 5 NPs can replace iodine-based CAs for diagnostic contrast-enhanced imaging of patients with kidney/heart diseases and improve the overall diagnostic index with negligible side effects. [ABSTRACT FROM AUTHOR]

Multifunctional stimuli-responsive nanotheranostic systems are highly desirable for realizing simultaneous biomedical imaging and on-demand therapy with minimized adverse effects. Herein, we present the construction of an intelligent X-ray-controlled NO-releasing upconversion nanotheranostic system (termed as PEG-USMSs-SNO) by engineering UCNPs with S-nitrosothiol (R-SNO)-grafted mesoporous silica. The PEG-USMSs-SNO is designed to respond sensitively to X-ray radiation for breaking down the S-N bond of SNO to release NO, which leads to X-ray dose-controlled NO release for on-demand hypoxic radiosensitization besides upconversion luminescent imaging through UCNPs in vitro and in vivo. Thanks to the high live-body permeability of Xray, our developed PEG-USMSs-SNO may provide a new technique for achieving depth-independent controlled NO release and positioned radiotherapy enhancement against deep-seated solid tumors. [ABSTRACT FROM AUTHOR]

Multifunctional stimuli‐responsive nanotheranostic systems are highly desirable for realizing simultaneous biomedical imaging and on‐demand therapy with minimized adverse effects. Herein, we present the construction of an intelligent X‐ray‐controlled NO‐releasing upconversion nanotheranostic system (termed as PEG‐USMSs‐SNO) by engineering UCNPs with S‐nitrosothiol (R‐SNO)‐grafted mesoporous silica. The PEG‐USMSs‐SNO is designed to respond sensitively to X‐ray radiation for breaking down the SN bond of SNO to release NO, which leads to X‐ray dose‐controlled NO release for on‐demand hypoxic radiosensitization besides upconversion luminescent imaging through UCNPs in vitro and in vivo. Thanks to the high live‐body permeability of X‐ray, our developed PEG‐USMSs‐SNO may provide a new technique for achieving depth‐independent controlled NO release and positioned radiotherapy enhancement against deep‐seated solid tumors. [ABSTRACT FROM AUTHOR]

Biophotonic technology that uses light and ionizing radiation for positioned cancer therapy is a holy grail in the field of biomedicine because it can overcome the systemic toxicity and adverse side effects of conventional chemotherapy. However, the existing biophotonic techniques fail to achieve the satisfactory treatment efficacy, which remains a big challenge for clinical implementation. Herein, we develop a novel theranostic technique of “intranuclear biophotonics” by the smart design of a nuclear-targeting biophotonic system based on photo-/radio-sensitizers covalently co-loaded upconversion nanoparticles. These nuclear-targeting biophotonic agents can not only generate a great deal of multiple cytotoxic reactive oxygen species in the nucleus by making full use of NIR/X-ray irradiation, but also produce greatly enhanced intranuclear synergetic radio-/photodynamic therapeutic effects under the magnetic/luminescent bimodal imaging guidance, which may achieve the optimal efficacy in treating radio-resistant tumors. We anticipate that the highly effective intranuclear biophotonics will contribute significantly to the development of biophotonic techniques and open new perspectives for a variety of cancer theranostic applications. [ABSTRACT FROM AUTHOR]

Abstract: This study synthesized Fe3O4 nanoparticles of 30–40nm by a sonochemical method, and these particles were uniformly dispersed on the reduced graphene oxide sheets (Fe3O4/RGO). The superparamagnetic property of Fe3O4/RGO was evidenced from a saturated magnetization of 30emu/g tested by a sample-vibrating magnetometer. Based on the testing results, we proposed a mechanism of ultrasonic waves to explain the formation and dispersion of Fe3O4 nanoparticles on RGO. A biosensor was fabricated by modifying a glassy carbon electrode with the combination of Fe3O4/RGO and hemoglobin. The biosensor showed an excellent electrocatalytic reduction toward H2O2 at a wide, linear range from 4×10−6 to 1×10−3 M (R 2 =0.994) as examined by amperometry, and with a detection limit of 2×10−6 M. The high performance of H2O2 detection is attributed to the synergistic effect of the combination of Fe3O4 nanoparticles and RGO, promoting the electron transfer between the peroxide and electrode surface. [Copyright &y& Elsevier]

A thermo-responsive drug delivery system was reported based on grafting of stimuli-responsive poly( N-isopropylacrylamide) (PNIPA) on the surface of graphene oxide (GO) via atom transfer radical polymerization. The successful synthesis of PNIPA attached on GO (GO-PNIPA) was confirmed by X-ray photoelectron spectrum, X-ray diffraction, atomic force microscope, field-emission scanning electron microscopy, and transmission electron microscopy measurements. Control of drug release through the composite GO-PNIPA was performed by measuring the uptake and release of ibuprofen (IBU). It was found the delivery system demonstrated a much high IBU storage of 280 wt%, attributing to the formation of the hydrogen bonding between the polymers on the GO surface and IBU as well as the large number of internal cavities of the PNIPA chains. In vitro test of IBU release exhibited a narrow pronounced transition at around 22 °C, indicating an attractive thermo-sensitive release property of this delivery system. The strategy may pave the way for the use of GO in numerous applications, from drug delivery to thermally responsive micro- and nano-devices. [ABSTRACT FROM AUTHOR]

Ein nanotheranostisches System bestehend aus aufwärtskonvertierenden Nanopartikeln (grüner Kern) und mesoporösem Siliciumdioxid (blaue Schale) mit S‐Nitrosothiolgruppen für den NO‐Transport in Tumoren wird von W. Bu, J. Shi et al. in der Zuschrift auf S. 14232 ff. vorgestellt. Hochenergetische Röntgenstrahlung (gezeigt als violetter Lichtstrahl) spaltet die schwache S‐N‐Bindung in der SNO‐Gruppe und setzt NO‐Moleküle (gezeigt als Bläschen) auf kontrollierte Weise frei. Dieses Prinzip liegt einer Methode zur Zerstörung tiefsitzender Tumoren zugrunde. [ABSTRACT FROM AUTHOR]