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DNA has shown great biocompatibility, programmable mechanical properties, and structural addressability at the nanometer scale, making it a versatile material for building high precision nanorobotics for biomedical applications. Herein, we present design principle, synthesis, and characterization of a DNA nanorobotic hand, called the “NanoGripper”, that contains a palm and four bendable fingers as inspired by human hands, bird claws, and bacteriophages evolved in nature. Each NanoGripper finger has three phalanges connected by two flexible and rotatable joints that are bendable in response to binding to other entities. Functions of the NanoGripper have been enabled and driven by the interactions between moieties attached to the fingers and their binding partners. We showcase that the NanoGripper can be engineered to interact with and capture various objects with different dimensions, including gold nanoparticles, gold NanoUrchins, and SARS-CoV-2 virions. When carrying multiple DNA aptamer nanoswitches programmed to generate fluorescent signal enhanced on a photonic crystal platform, the NanoGripper functions as a sensitive viral biosensor that detects intact SARS-CoV-2 virions in human saliva with a limit of detection of ∼ 100 copies/mL, providing RT-PCR equivalent sensitivity. Additionally, we use confocal microscopy to visualize how the NanoGripper-aptamer complex can effectively block viral entry into the host cells, indicating the viral inhibition. In summary, we report the design, synthesis, and characterization of a complex nanomachine that can be readily tailored for specific applications. The study highlights a path toward novel, feasible, and efficient solutions for the diagnosis and therapy of other diseases such as HIV and influenza.One-sentence summaryDesign, synthesis, characterization, and functional showcase of a human-hand like designer DNA nanobot

Recent times have experienced more than ever the impact of viral infections in humans. Viral infections are known to cause diseases not only in humans but also in plants and animals. Here, we have compiled the literature review of aptamers selected and used for detection and inhibition of viral infections in all three categories: humans, animals, and plants. This review gives an in-depth introduction to aptamers, different types of aptamer selection (SELEX) methodologies, the benefits of using aptamers over commonly used antibody-based strategies, and the structural and functional mechanism of aptasensors for viral detection and therapy. The review is organized based on the different characterization and read-out tools used to detect virus-aptasensor interactions with a detailed index of existing virus-targeting aptamers. Along with addressing recent developments, we also discuss a way forward with aptamers for DNA nanotechnology-based detection and treatment of viral diseases. Overall, this review will serve as a comprehensive resource for aptamer-based strategies in viral diagnostics and treatment.

p class="Abstract" style="margin: 0in 0in 30pt; text-align: justify; line-height: 11.25pt; font-size: 8pt; font-family: Arial, sans-serif; caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0);"a name="_Hlk123034094"span lang="EN-GB"Exosomal microRNAs (miRNAs) have considerable potential as pivotal biomarkers to monitor cancer development, dis-ease progression, treatment effects and prognosis. Here, we report an efficient target recycling amplification process (TRAP) for the digital detection of miRNAs using photonic resonator absorption microscopy. We achieve multiplex digital detection with sub-attomolar sensitivity in 20 minutes, robust selectivity for single nucleotide variants, and a broad dynamic range from 1 aM to 1 pM. Compared with traditional qRT-PCR, TRAP showed similar accuracy in profiling exosomal miRNAs derived from cancer cells, but also exhibited at least 31-fold and 61-fold enhancement in the limits of miRNA-375 and miRNA-21 detection, respectively. The TRAP approach is ideal for exosomal or circulating miRNA biomarker quantification, where the miRNAs are present in low concentrations or sample volume, with potentials for frequent, low-cost, and minimally invasive point-of-care testing./span/aspan lang="EN-GB"o:p/o:p/span/p.

Exosomal microRNAs (miRNAs) have considerable potential as pivotal biomarkers to monitor cancer development, dis-ease progression, treatment effects and prognosis. Here, we report an efficient target recycling amplification process (TRAP) for the digital detection of exosomal miRNAs using photonic resonator absorption microscopy (PRAM). Through toehold-mediated DNA strand displacement reactions, we achieve multiplex digital detection with sub-attomolar sensitivity in 20 minutes, robust selectivity for single nucleotide variants, and a broad dynamic range from 1 aM to 1 pM. We then applied our TRAP system to quantify miRNA in exosomal total RNAs isolated from human cancer cell lines. Compared with traditional qRT-PCR methods, TRAP showed similar accuracy in profiling exosomal miRNAs derived from cancer cells, but also exhibited at least 31-fold and 61-fold enhancement in the limits of miRNA-375 and miRNA-21 detection, respectively. The TRAP approach is ideal for exosomal or circulating miRNA biomarker quantification, where the miRNAs are present in low concentrations or sample volume, with potentials for frequent, low-cost, and minimally invasive point-of-care testing.

Assays utilizing molecular fluorophores are common throughout life science research and diagnostic testing, although detection limits are generally limited by weak emission intensity, thus requiring many labeled target molecules to combine their output to achieve signal-to-noise greater than the background. Here, we describe how the synergistic coupling of plasmonic and photonic resonance modes can significantly boost the emission from fluorescent dye molecules without increasing the illumination intensity while utilizing a microscopy approach with a broad field of view. By optimally matching the resonant modes of a plasmonic fluor (PF) nanoparticle and a photonic crystal (PC) surface with the absorption and emission spectrum of the PF’s fluorescent dye, we observe a 52-fold improvement in signal intensity, enabling individual PFs to be observed and digitally counted, using an approach in which one PF tag represents detection of one target molecule. The photonic amplification from the PF can be attributed to the strong near-field enhancement due to the cavity-induced activation of the PF, PC band structure-mediated improvement in collection efficiency of emitted photons, and increased rate of spontaneous emission. We demonstrate the applicability of the method by dose-response characterization of a sandwich immunoassay for human interleukin-6, a biomarker commonly used to assist diagnosis of cancer, inflammation, sepsis, and autoimmune disease. We achieve a limit of detection of 10 fg/ml, representing a capability three orders of magnitude lower than standard immunoassays.

Astrocytes, the multi-functional glial cells with the most abundant population in the brain, integrate information across their territories to regulate neuronal synaptic and cerebrovascular activities. Astrocytic calcium (Ca

We present a net-shaped DNA nanostructure (called "DNA Net" herein) design strategy for selective recognition and high-affinity capture of intact SARS-CoV-2 virions through spatial pattern-matching and multivalent interactions between the aptamers (targeting wild-type spike-RBD) positioned on the DNA Net and the trimeric spike glycoproteins displayed on the viral outer surface. Carrying a designer nanoswitch, the DNA Net-aptamers release fluorescence signals upon virus binding that are easily read with a handheld fluorimeter for a rapid (in 10 min), simple (mix-and-read), sensitive (PCR equivalent), room temperature compatible, and inexpensive (∼$1.26/test) COVID-19 test assay. The DNA Net-aptamers also impede authentic wild-type SARS-CoV-2 infection in cell culture with a near 1 × 10

We present a net-shaped DNA nanostructure (called “DNA Net” herein) design strategy for selective recognition and high-affinity capture of the intact SARS-CoV-2 virions through spatial pattern-matching and multivalent interactions between the aptamers (targeting wild type spike-RBD) positioned on the DNA Net and the trimeric spike glycoproteins displayed on the viral outer surface. Carrying a designer nanoswitch, the DNA Net-aptamers releases fluorescent signal upon virus binding that is easily read by a hand-held fluorimeter for a rapid (in 10 mins), simple (mix- and-read), sensitive (PCR equivalent), room temperature compatible, and inexpensive (∼ $1.26/test) COVID-19 test assay. The DNA Net-aptamers also impede authentic wild-type SARS-CoV-2 infection in cell culture with a near 1×103-fold enhancement of the monomeric aptamer. Furthermore, our DNA Net design principle and strategy can be customized to tackle other life-threatening and economically influential viruses like influenza and HIV, whose surfaces carry class-I viral envelope glycoproteins like the SARS-CoV-2 spikes in trimeric forms.

Diffusion-weighted imaging has produced useful biomarkers of verbal fluency post-stroke but acquiring diffusion data is not always clinically feasible. Further, it has been demonstrated that subcortical regions may contribute to verbal fluency, though the predominant focus in the literature has been on cortical contributions to verbal fluency. Finally, the majority of recovery-oriented research on language in stroke has been cross-sectional, which does not allow for actual modelling of language change over time. Focusing on the contribution of subcortical and white matter structures to language recovery of individuals with ischaemic stroke, our present study, therefore, used the information of white matter disconnection and volumetric measurements obtained directly from non-diffusion-weighted anatomical images (T1, T2 and FLAIR), which are routinely acquired in clinical settings, to understand verbal fluency performance over time. We derived neuropsychological and anatomical neuroimaging data of individuals at 3- and 12-months post-stroke from the Cognition And Neocortical Volume After Stroke study, a longitudinal study of ischaemic stroke survivors and healthy stroke-free individuals. Cortical volumetric and thickness measurements were derived from FreeSurfer. White matter disconnection was quantified by two metrics based on BCBToolkit: Disconnection severity – the proportion of lesioned voxel volume to the total volume of a tract, and disconnection probability – the probability of the overlap between a subject’s lesion and a tract. Using the linear mixed multiple regression method based on 5-fold cross-validation, we correlated the semantic and phonemic fluency scores of participants with longitudinal measurements of subcortical grey matter volume and 22 literature-driven bilateral white matter tracts of interests, while controlling for demographic variables (age, sex, handedness and education), total brain volume, lesion volume, and cortical thickness at both time points.Our results showed that the right subcortical grey matter volume was positively associated with phonemic fluency (p < 0.05) from 3 months to 12 months post-stroke and the model predictions improved with cross-validation. The disconnection probability of the left superior longitudinal fasciculus II and the left posterior arcuate fasciculus was negatively correlated to semantic fluency (p < 0.05) from 3 months to 12 months post-stroke, but this model did not generalize well following cross-validation.We conclude that subcortical grey matter volume is strongly related to phonemic fluency recovery after stroke, and that the association of white matter disruptions with semantic fluency recovery are strongly influenced by the specific lesion features of the stroke patients within the present study.

We report 3,000-fold signal enhancement with blinking suppression capability and single QD sensitivity using low-NA lens. Applied toward miRNA detection assays, we achieve single-base mutation selectivity, and 10-attomolar detection limit.

In recent years, the biosensor research community has made rapid progress in the development of nanostructured materials capable of amplifying the interaction between light and biological matter. A common objective is to concentrate the electromagnetic energy associated with light into nanometer-scale volumes that, in many cases, can extend below the conventional Abbé diffraction limit. Dating back to the first application of surface plasmon resonance (SPR) for label-free detection of biomolecular interactions, resonant optical structures, including waveguides, ring resonators, and photonic crystals, have proven to be effective conduits for a wide range of optical enhancement effects that include enhanced excitation of photon emitters (such as quantum dots, organic dyes, and fluorescent proteins), enhanced extraction from photon emitters, enhanced optical absorption, and enhanced optical scattering (such as from Raman-scatterers and nanoparticles). The application of photonic metamaterials as a means for enhancing contrast in microscopy is a recent technological development. Through their ability to generate surface-localized and resonantly enhanced electromagnetic fields, photonic metamaterials are an effective surface for magnifying absorption, photon emission, and scattering associated with biological materials while an imaging system records spatial and temporal patterns. By replacing the conventional glass microscope slide with a photonic metamaterial, new forms of contrast and enhanced signal-to-noise are obtained for applications that include cancer diagnostics, infectious disease diagnostics, cell membrane imaging, biomolecular interaction analysis, and drug discovery. This paper will review the current state of the art in which photonic metamaterial surfaces are utilized in the context of microscopy.

The use of rodents to acquire understanding of the function of neural circuits and of the physiological, genetic and developmental underpinnings of behaviour has been constrained by limitations in the scalability, automation and high-throughput operation of implanted wireless neural devices. Here, we report scalable and modular hardware and software infrastructure for setting up and operating remotely programmable miniaturized wireless networks leveraging Bluetooth Low Energy for the study of the long-term behaviour of large groups of rodents. The integrated system allows for automated, scheduled and real-time experimentation via the simultaneous and independent use of multiple neural devices and equipment within and across laboratories. By measuring the locomotion, feeding, arousal and social behaviours of groups of mice or rats, we show that the system allows for bidirectional data transfer from readily available hardware, and that it can be used with programmable pharmacological or optogenetic stimulation. Scalable and modular wireless-network infrastructure should facilitate the remote operation of fully automated large-scale and long-term closed-loop experiments for the study of neural circuits and animal behaviour.

Both in vivo neuropharmacology and optogenetic stimulation can be used to decode neural circuitry, and can provide therapeutic strategies for brain disorders. However, current neuronal interfaces hinder long-term studies in awake and freely behaving animals, as they are limited in their ability to provide simultaneous and prolonged delivery of multiple drugs, are often bulky and lack multifunctionality, and employ custom control systems with insufficiently versatile selectivity for output mode, animal selection and target brain circuits. Here, we describe smartphone-controlled, minimally invasive, soft optofluidic probes with replaceable plug-like drug cartridges for chronic in vivo pharmacology and optogenetics with selective manipulation of brain circuits. We demonstrate the use of the probes for the control of the locomotor activity of mice for over four weeks via programmable wireless drug delivery and photostimulation. Owing to their ability to deliver both drugs and photopharmacology into the brain repeatedly over long time periods, the probes may contribute to uncovering the basis of neuropsychiatric diseases.

This ERP study of Chinese subject- and object-modifying relative clauses (RCs) aimed at investigating how sentence context (embeddedness) temporally interacted with relativization in terms of processing load. In stead of adotping a static view of processing costs of RCs, we focused on the dynamic modulation of processing load by sentence context at two critical words–the relative marker de and head noun. Using cluster-based permutation analyses of ERPs, our study found an early relativization effect (110–220 ms) followed by an embeddedness effect (411–441 ms) and a late interaction effect (540–620 ms) at the relative marker de. The main effect of relativization as an early left anterior negativity suggests a transitory processing advantage of subject-relativization independent of sentence context. The sentence context was processed just 410 ms after word onset as a late left-lateralized anterior negativity for the center-embedded RCs, indicating increased working memory load introduced by sentence context constraints. A late centro-posterior positivity registered for object-relativization RCs with preceding sentence context due to structural reanalysis. An early anterior negativity (73–123 ms) reflecting the embeddedness effect at the head noun suggests the complexity of information encoded in phrase markers when semantic contents of verb arguments are instantiated. Our results indicate that it is necessary to adjust the account of RC processing beyond a universal processing advantage for subject-relativization to integrate the effects of sentence context cross-linguistically.

Newly demonstrated advanced biosensor imaging technologies utilize the unique electromagnetic capabilities of photonic metamaterials to enhance the interaction between light and biological matter. The resulting capabilities address gaps in existing technologies for biomolecular analysis that rely upon enzymatic and chemical amplification, costly instrumentation, and complex assay protocols. Through amplification of the excitation/extraction efficiency of light emitting tags, absorption efficiency of nanoparticle tags, and scattering efficiency of biological analytes, technology platforms have been demonstrated that are capable of ultrasensitive, digital-resolution, room temperature, isothermal, rapid, and highly quantitative biomolecular analysis.

Eye movement is not only for adjusting the visual field and maintaining the stability of visual information on the retina, but also provides an external manifestation of the cognitive status of the brain. Recent studies showed similarity in eye movement patterns between wakefulness and rapid eye movement (REM) sleep, indicating that the brain status of REM sleep likely resembles that of awake status. REM sleep in humans could be divided into phasic REM and tonic REM sleep according to the difference in eye movement frequencies. Mice are the most commonly used animal model for studying neuronal and molecular mechanisms underlying sleep. However, there was a lack of details for eye movement patterns during REM sleep, hence it remains unknown whether REM sleep can be further divided into different stages in mice. Here we developed a device combining electroencephalogram (EEG), electromyogram (EMG) as well as eye movements recording in mice to study the eye movement patterns during sleep. We implanted a magnet beneath the conjunctiva of eye and tracked eye movements using a magnetic sensor. The magnetic signals showed strong correlation with video-oculography in head-fixed mice, indicating that the magnetic signals reflect the direction and magnitude of eye movement. We also found that the magnet implanted beneath the conjunctiva exhibited good biocompatibility. Finally, we examined eye movement in sleep–wake cycle, and discriminated tonic REM and phasic REM according to the frequency of eye movements, finding that compared to tonic REM, phasic REM exhibited higher oscillation power at 0.50 Hz, and lower oscillation power at 1.50–7.25 Hz and 9.50–12.00 Hz. Our device allowed to simultaneously record EEG, EMG, and eye movements during sleep and wakefulness, providing a convenient and high temporal-spatial resolution tool for studying eye movements in sleep and other researches in mice.

One of the frontiers in the field of biosensors is the ability to quantify specific target molecules with enough precision to count individual units in a test sample, and to observe the characteristics of individual biomolecular interactions. Technologies that enable observation of molecules with "digital precision" have applications for in vitro diagnostics with ultra-sensitive limits of detection, characterization of biomolecular binding kinetics with a greater degree of precision, and gaining deeper insights into biological processes through quantification of molecules in complex specimens that would otherwise be unobservable. In this review, we seek to capture the current state-of-the-art in the field of digital resolution biosensing. We describe the capabilities of commercially available technology platforms, as well as capabilities that have been described in published literature. We highlight approaches that utilize enzymatic amplification, nanoparticle tags, chemical tags, as well as label-free biosensing methods.

We report on a time-frequency analysis of electroencephalographic activity as native speakers (NSs) and non-native speakers (NNSs) resolve anaphoric reference at the recursive edge of embedded clauses in multi-clausal filler-gap dependencies. The fillers in these wh-dependencies involve lexically selected noun complements (Comp): quelle decision a propos de lui/a son sujet ‘which decision about him’ or unselected NP-modifiers (Mod): quelle decision le concernant ‘which decision regarding him’; they also involve the lexical encoding of antecedent gender (lui/elle ‘3p.sing.masc/fem’) or not (son ‘3p.sing.gen’) in a pronoun. We propose that NNSs adapt to processing a non-native language by directing more resources toward computing lexically encoded properties than toward inferences that go beyond lexical information. At the recursive clause edge, a population-wide asymmetry between conditions arose at 15–16Hz in induced power: Lexical selection and gender specification led to diminished power for Comp son vs. Mod le/la and for specified lui/elle vs. unspecified son in Comps. This was also found at 17–22Hz in induced power in NSs whereas asymmetries were reversed in NNSs, with computations of lexically encoded properties demanding greater power. At 41–44Hz in induced power, group differences emerged: More power was directed at gender-specified le/la and lui/elle in NNSs, but at unspecified son in NSs. These asymmetries suggest that non-native processing seems characterized by resources directed toward lexically encoded properties in computations.

This publisher’s notes amends the funding of [Biomed. Opt. Express 12, 4637 (2021)10.1364/BOE.427475].