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The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs’ chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality. This review summarizes the methodology for fabricating ultrasensitive and selective Zn-MOF-based sensors, as well as their application in early cancer diagnosis and therapy. This review also offers a systematic approach to understanding the development of MOFs as efficient drug carriers and provides new insights on their applications and limitations in utility with possible solutions.

The coherent transmission technology using digital signal processing and advanced modulation formats, is bringing networks closer to the theoretical capacity limit of optical fibres, the Shannon limit. The in-phase/quadrature electro-optic modulator that encodes information on both the amplitude and the phase of light, is one of the underpinning devices for the coherent transmission technology. Ideally, such modulator should feature a low loss, low drive voltage, large bandwidth, low chirp and compact footprint. However, these requirements have been only met on separate occasions. Here, we demonstrate integrated thin-film lithium niobate in-phase/quadrature modulators that fulfil these requirements simultaneously. The presented devices exhibit greatly improved overall performance (half-wave voltage, bandwidth and optical loss) over traditional lithium niobate counterparts, and support modulation data rate up to 320 Gbit s −1 . Our devices pave new routes for future high-speed, energy-efficient, and cost-effective communication networks. In-phase/quadrature (IQ) electro-optic modulators are underpinning devices for coherent transmission technology. Here the authors present IQ modulators in the lithium-niobate-on-insulator platform, which provide improved overall performance and advanced modulation formats for future coherent transmission systems.

This approach uses fluorescently labeled aptamers and graphene oxide nanosheets to adsorb the aptamers and quench fluorescence. Ligand (e.g., ATP or GTP) binding results in the release of aptamers into solution and fluorescence is \"turned on\". Here we present a detailed protocol for in situ multiple fluorescence monitoring of adenosine-5′-triphosphate (ATP) and guanosine-5′-triphosphate (GTP) in MCF-7 breast cancer cells by using graphene oxide nanosheet (GO-nS) and DNA/RNA aptamers. FAM-labeled ATP aptamer and Cy5-modified GTP aptamer are used to construct the multiple aptamer/GO-nS sensing platform through 'π-π stacking' between aptamers and GO-nS. Binding of aptamers to GO-nS guarantees the fluorescence resonance energy transfer between fluorophores and GO-nS, resulting in 'fluorescence off'. When the aptamer/GO-nS are transported inside the cells via endocytosis, the conformation of the aptamers will change on interaction with cellular ATP and GTP. On the basis of the fluorescence 'off/on' switching, simultaneous sensing and imaging of ATP and GTP in vitro and in situ have been realized through fluorescence and confocal microscopy techniques. In this protocol, we describe the synthesis of GO and GO-nS, preparation of aptamer/GO-nS platform, in vitro detection of ATP and GTP, and how to use this platform to realize intracellular ATP and GTP imaging in cultured MCF-7 cells. The preparation of GO-nS is anticipated to take 7–14 d, and assays involving microscopy imaging and MCF-7 cells culturing can be performed in 2–3 d.

Graphene is the basic building block of 0D fullerene, 1D carbon nanotubes, and 3D graphite. Graphene has a unique planar structure, as well as novel electronic properties, which have attracted great interests from scientists. This review selectively analyzes current advances in the field of graphene bioapplications. In particular, the biofunctionalization of graphene for biological applications, fluorescence-resonance-energy-transfer-based biosensor development by using graphene or graphene-based nanomaterials, and the investigation of graphene or graphene-based nanomaterials for living cell studies are summarized in more detail. Future perspectives and possible challenges in this rapidly developing area are also discussed.

Carbon dots (CDs) have a wide range of applications in chemical, physical and biomedical research fields. We are particularly interested in the use of CDs as fluorescence nanomaterials for targeted tumor cell imaging. One of the important aspects of success is to enhance the fluorescence quantum yields (QY) of CDs as well as increase their targetability to tumor cells. However, most of the reported CDs are limited by relative low QY. In the current study, for the first time, one-step synthesis of highly luminescent CDs by using folic acid (FA) as single precursor was obtained in natural water through hydrothermal method. The as-prepared CDs exhibited QY as high as 94.5% in water, which is even higher than most of organic fluorescent dyes. The obtained CDs showed excellent photoluminescent activity, high photostability and favorable biocompatibility. The FA residuals in CDs led to extraordinary targetability to cancer cells and promoted folate receptor-mediated cellular uptake successfully, which holds a great potential in biological and bioimaging studies.

This study aimed to evaluate the effects of trilobatin (TLB) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice and further explore the underlying mechanisms from the perspectives of signaling pathway and gut microbiota. A mouse model of UC was established using DSS. Trilobatin was administered via oral gavage. Disease severity was assessed based on body weight, disease activity index (DAI), colon length, histological detection, inflammation markers, and colonic mucosal barrier damage. Alternations in the NF-κB and PI3K/Akt pathways were detected by marker proteins. High-throughput 16S rRNA sequencing was performed to investigate the gut microbiota of mice. In the DSS-induced UC mice, TLB (30 μg/g) treatment significantly increased the body weight, reduced the DAI score, alleviated colon length shortening, improved histopathological changes in colon tissue, inhibited the secretion and expression of inflammation factors (TNF-α, IL-1β, and IL-6), and increased the expression of tight-junction proteins (ZO-1 and occludin). Furthermore, TLB (30 μg/g) treatment significantly suppressed the activation of NF-κB pathway and altered the composition and diversity of the gut microbiota, as observed in the variations of the relative abundances of Proteobacteria, Actinobacteriota, and Bacteroidota, in UC mice. TLB effectively alleviates DSS-induced UC in mice. Regulation of the NF-κB pathway and gut microbiota contributes to TLB-mediated therapeutic effects. Our study not only identified a novel drug candidate for the treatment of UC, but also enhanced our understanding of the biological functions of TLB.

As a new seismological monitoring technology, distributed acoustic sensing (DAS) not only provides a high-precision seismic observation method, but also uses undersea communication fiber or dark fiber to reduce the layout cost, and supports long-term observation for several years, and the sensing resolution reaches the scale of meters. This technique provides a broad prospect for seismic observation in oceanic area which is difficult to be covered by traditional seismic observation instruments. In this paper, we analyzed the DAS waveforms of 10 local-earthquake events waveforms recorded by offshore submarine communication cable in the northern South China Sea, and discussed the response ability of DAS system based on shallow sea communication cable to near-earthquake. It is found that the signals are affected by surface gravitational waves and micro seismic noise (Scholte Wave) generated by solid–liquid coupling motion. Then, waveform stacking, discrete wavelet transform, and empirical mode decomposition are used to denoise the signal in shallow sea area for extracting earthquake waveform. Submarine optical cable is the most widely distributed submarine signal monitoring system in the world. Long-term and cheap deep-sea seismic wave observation based on such the large-scale global ocean observation network can provide important data for the development of seismology.

Photoacoustic tomography (PAT), also known as optoacoustic tomography, is an attractive imaging modality that provides optical contrast with acoustic resolutions. Recent progress in the applications of PAT largely relies on the development and employment of ultrasound sensor arrays with many elements. Although on-chip optical ultrasound sensors have been demonstrated with high sensitivity, large bandwidth, and small size, PAT with on-chip optical ultrasound sensor arrays is rarely reported. In this work, we demonstrate PAT with a chalcogenide-based micro-ring sensor array containing 15 elements, while each element supports a bandwidth of 175 MHz (−6 dB) and a noise-equivalent pressure of 2.2 mPaHz −1/2 . Moreover, by synthesizing a digital optical frequency comb (DOFC), we further develop an effective means of parallel interrogation to this sensor array. As a proof of concept, parallel interrogation with only one light source and one photoreceiver is demonstrated for PAT with this sensor array, providing images of fast-moving objects, leaf veins, and live zebrafish. The superior performance of the chalcogenide-based micro-ring sensor array and the effectiveness of the DOFC-enabled parallel interrogation offer great prospects for advancing applications in PAT. The authors report a highly sensitive chalcogenide-based micro-ring sensor array for photoacoustic tomography and develops a compatible parallel interrogation means by synthesizing a digital optical frequency comb. Imaging is demonstrated on fast-moving objects, leaf veins, and live zebrafish.

Single-pixel holography (SPH) is capable of generating holographic images with rich spatial information by employing only a single-pixel detector. Thanks to the relatively low dark-noise production, high sensitivity, large bandwidth, and cheap price of single-pixel detectors in comparison to pixel-array detectors, SPH is becoming an attractive imaging modality at wavelengths where pixel-array detectors are not available or prohibitively expensive. In this work, we develop a high-throughput single-pixel compressive holography with a space-bandwidth- time product (SBP-T) of 41,667 pixels/s, realized by enabling phase stepping naturally in time and abandoning the need for phase-encoded illumination. This holographic system is scalable to provide either a large field of view (~83 mm 2 ) or a high resolution (5.80 μm × 4.31 μm). In particular, high-resolution holographic images of biological tissues are presented, exhibiting rich contrast in both amplitude and phase. This work is an important step towards multi-spectrum imaging using a single-pixel detector in biophotonics. Single-pixel holography generates holographic images with a single-pixel detector making this relatively inexpensive. Here the authors report a high-throughput single-pixel compressive holography method for imaging biological tissue which can either provide a large field of view or high resolution.

Background Oxidation and peroxidation of lipids in microorganisms result in increased levels of intracellular reactive oxygen species (ROS) and reactive aldehydes, and consequent reduction of cell growth and lipid accumulation. Results To reduce oxygen-mediated cell damage and increase lipid and docosahexaenoic acid (DHA) production in Schizochytrium sp., we strengthened the oxidative stress defense pathways. Overexpression of the enzymes thioredoxin reductase (TRXR), aldehyde dehydrogenase (ALDH), glutathione peroxidase (GPO), and glucose-6-phosphate dehydrogenase (ZWF) strongly promoted cell growth, lipid yield, and DHA production. Coexpression of ZWF, ALDH, GPO, and TRXR enhanced ROS-scavenging ability. Highest values of dry cell weight, lipid yield, and DHA production (50.5 g/L, 33.1 g/L, and 13.3 g/L, respectively) were attained in engineered strain OaldH-gpo-trxR by shake flask fed-batch culture; these were increases of 18.5%, 80.9%, and 114.5% relative to WT values. Conclusions Our findings demonstrate that engineering of oxidative stress defense pathways is an effective strategy for promoting cell robustness, lipid yield, and DHA production in Schizochytrium.