Search

Abstract Current soft neural probes are still operated by bulky, rigid electronics mounted to a body, which deteriorate the integrity of the device to biological systems and restrict the free behavior of a subject. We report a soft, conformable neural interface system that can monitor the single-unit activities of neurons with long-term stability. The system implements soft neural probes in the brain, and their subsidiary electronics which are directly printed on the cranial surface. The high-resolution printing of liquid metals forms soft neural probes with a cellular-scale diameter and adaptable lengths. Also, the printing of liquid metal-based circuits and interconnections along the curvature of the cranium enables the conformal integration of electronics to the body, and the cranial circuit delivers neural signals to a smartphone wirelessly. In the in-vivo studies using mice, the system demonstrates long-term recording (33 weeks) of neural activities in arbitrary brain regions. In T-maze behavioral tests, the system shows the behavior-induced activation of neurons in multiple brain regions.

Abstract Detecting early cancer through liquid biopsy is challenging due to the lack of specific biomarkers for early lesions and potentially low levels of these markers. The current study systematically develops an extracellular‐vesicle (EV)‐based test for early detection, specifically focusing on high‐grade serous ovarian carcinoma (HGSOC). The marker selection is based on emerging insights into HGSOC pathogenesis, notably that it arises from precursor lesions within the fallopian tube. This work thus establishes murine fallopian tube (mFT) cells with oncogenic mutations and performs proteomic analyses on mFT‐derived EVs. The identified markers are then evaluated with an orthotopic HGSOC animal model. In serially‐drawn blood of tumor‐bearing mice, mFT‐EV markers increase with tumor initiation, supporting their potential use in early cancer detection. A pilot clinical study (n = 51) further narrows EV markers to five candidates, EpCAM, CD24, VCAN, HE4, and TNC. The combined expression of these markers distinguishes HGSOC from non‐cancer with 89% sensitivity and 93% specificity. The same markers are also effective in classifying three groups (non‐cancer, early‐stage HGSOC, and late‐stage HGSOC). The developed approach, for the first time inaugurated in fallopian tube‐derived EVs, could be a minimally invasive tool to monitor women at high risk of ovarian cancer for timely intervention.

High-throughput imaging has generally been challenging for scanning probe microscopy techniques. Here, the authors introduce binary-state scanning probe microscopy, which uses a cantilever-free elastomeric probes and a hierarchical measurement architecture for parallel topography imaging.

Abstract CRISPR/Cas systems offer a powerful sensing mechanism to transduce sequence‐specific information into amplified analytical signals. However, performing multiplexed CRISPR/Cas assays remains challenging and often requires complex approaches for multiplexed assays. Here, a hydrogel‐based CRISPR/Cas12 system termed CLAMP (Cas‐Loaded Annotated Micro‐Particles) is described. The approach compartmentalizes the CRISPR/Cas reaction in spatially‐encoded hydrogel microparticles (HMPs). Each HMP is identifiable by its face code and becomes fluorescent when target DNA is present. The assay is further streamlined by capturing HMPs inside a microfluidic device; the captured particles are then automatically recognized by a machine‐learning algorithm. The CLAMP assay is fast, highly sensitive (attomolar detection limits with preamplification), and capable of multiplexing in a single‐pot assay. As a proof‐of‐concept clinical application, CLAMP is applied to detect nucleic acid targets of human papillomavirus in cervical brushing samples.

Photolithography is an established microfabrication technique but commonly uses costly shortwavelength light sources to achieve high resolution. Here the authors use metal patterns embedded in a flexible elastomer photomask with mechanical robustness for generation of subdiffraction patterns as a cost effective near-field optical printing approach.

The emergence of applications requiring device-to-device interactivity has to the need to develop conducting electrodes with high optical transparency at low radiofrequencies. Here, the authors demonstrate conductive polymer electrodes with high transparency in the MHz-order frequency range.

Abstract The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and Cu0.5Au0.5CN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h‐BN, WS2, MoS2, WSe2, MoSe2, and MoTe2). The potential energy landscape of the hexagonal lattice induces this preferred alignment of 1D chains along the zigzag lattice directions, regardless of the lattice parameter and surface elements as demonstrated by first‐principles calculations and parameterized surface potential calculations. Furthermore, the oriented microwires can serve as crystal orientation markers, and stacking‐angle‐controlled vertical 2D heterostructures are successfully fabricated by using them as markers. The oriented van der Waals epitaxy can be generalized to any hexagonal 2D crystals and will serve as a unique growth process to form crystals with orientations along the zigzag directions by epitaxy.

The imaging and diagnosis with magnetic resonance imaging could be greatly benefitted by the use of contrast agents based on magnetic nanoparticles. Several strategies for enhancing sensitivity and accuracy have been introduced which include the enhancement of magnetization values and multi-modal imaging techniques. Especially multi-modalities into which several complementary imaging modalities are converged can greatly reduce possible false-positive signals and enhance diagnosing accuracy. We here explain some examples of integration strategies to achieve this high accuracy.

A redox-transmetalation process that is effective as a general protocol for the fabrication of high quality and well-defined core-shell type bimetallic nanoparticles on the sub-10 nm scale is presented. The nanostructures, magnetic properties and reaction byproducts of the core-shell nanomaterial including Co@Au, Co@Pd, Co@Pt and nanoparticles are spectroscopically characterized and identified to confirm the chemical process that promotes the core-shell structure formation.

An efficient method for the fabrication of a single electron transistor (SET) using DNA-assisted assembly of nanoparticles is reported. In this method, the DNA molecules function not only as the assembler, but also as the modulator for the electron tunneling behaviors of single electron transistors.

The article explains a newly devised core-shell design concept, which can be used for the fabrication of the dual mode nanoparticle contrast agents (DMCAs). These agents are shown to be extremely beneficial for the enhancement of the accuracy of MR imaging.

A novel material that has incorporated zinc-doped iron oxide nanocrystals within a mesoporous silica framework that is surface-modified with pseudorotaxanes is described. This material is shown to be a noninvasive, externally controlled drug delivery system with cancer-killing properties.

The article discusses the significance of the nanoscaling laws of magnetic nanoparticles in studying the behavior of existing materials and for being used in the field of biomedical sciences. These laws are found to be extremely useful for optimizing the magnetic properties of the nanoparticles, hence increasing their applicabilities.

The development of heterodimer nanoparticles of FePt-Au with multifunctionalities is described. The catalytic effects of FePt for heteroepitaxial Au growth, high water-solubility and biocompatibility attained through versatile ligand chemistry of Au-S linkages, Au for chip-based biosensing and magnetic resonance (MR) contrast effects of superparamagnetic FePt are determined.

The progress on the synthetic development of symmetry-controlled colloidal nanocrystals of semiconductor and metal oxide prepared through nonhydrolytic chemical routes is reported. The shape of the nanocrystal was determined with the help of the crystalline phase of nucleating seeds, surface energy, kinetic vs thermodynamic growth and selective adhesion processes of capping ligands.

A surface-modulated and highly biocompatible magnetic iron oxide nanocrystal probe that could be used for efficient intracellular labeling and their magnetic resonance imaging applications is presented. The preparation of these probes and the results from studies exploring their transport into various cell types and magnetic resonance contrast effect, cytotoxicity, and application in vivo monitoring of neural stem cell migration in rat spinal cord is described.

An easy and reliable method for the production of patterned monolayers of Co nanoparticles is described. A two-dimensional monolayer of Co nanoparticles is fabricated by spreading a nanoparticle solution over an air-water interface and then transferring it to a hydrophobic substrate by using the Langmuir-Blodgett (LB) method.

A report is presented on the development of a synthetically controlled magnetic nanocrystal model system that correlates the nanoscale tunabilities in terms of size, magnetism, and an induced nuclear spin relaxation processes. The magnetic model system further leads to the development of high-performance magnetic nanocrytsal probe systems for diagnosis of breast cancer lines.

A general and highly effective one-pot synthetic protocol to produce 1-dimensional nanostructures of transition metal oxide through thermally induced crystal growth processes from a mixture of metal chloride and surfactants are presented. The general applicability of the synthetic protocol was tested to V(sub 2)O(sub 5) nanocrystals was tested where 1-D shaped nanocrystals could also be obtained.

The shape evolutions of magnetic iron oxide nanocrystals utilizing a simple one-step synthesis without any additional reagents such as (CH3)(sub 3)NO are reported. These types of studies concerning the shape evolution of nanocrystals should be valuable for further design and for greater understanding of advanced nanoscale building-block architectures.

It is demonstrated that a series of shape evolutions ranging from anisotropic to isotropic forms is possible even in highly symmetric rock-salt phased semiconductors. The initial injection of molecular precursor into hot solvent immediately results in the formation of truncated octahedron-shaped nuclei terminated by two characteristic faces: {100} faces with high surface energy and {111} faces with low surface energy in the presence of strong adsorbent.

The magnetic semicontrolled nanocrystals, which are shape and dopant controlled, have been achieved by the thermolysis of nonpyrophoric and less reactive single molecular precursors under a monosurfactant system. Reaction parameters governing both the intrinsic crystalline phase and the growth regime are important for the synthesis of various shapes of MnS nanocrystals that include cubes, spheres, 1-dimensional (1-D) monowires, and branched wires (bipods, tripods, and tetrapods).

A route for shape and crystalline phase control of GaP (gallium phosphide) nanocrystals is successfully developed using a single molecular precursor approach. The first liquid phase syntheses of anisotropic III-V semiconductor within a quantum-confined region with a width of less than 10 nm.

Developing innovative tools that facilitate the understanding of sophisticated biological systems has been one of the Holy Grails in the physical and biological sciences. In this Commentary, we discuss recent advances, opportunities, and challenges in the use of nanomaterials as a precision tool for biology and medicine. [ABSTRACT FROM AUTHOR]