The Current State of Realistic Heart Models for Disease Modelling and Cardiotoxicity.

One of the many unresolved obstacles in the field of cardiovascular research is an uncompromising in vitro cardiac model. While primary cell sources from animal models offer both advantages and disadvantages, efforts over the past half-century have aimed to reduce their use. Additionally, obtaining a sufficient quantity of human primary cardiomyocytes faces ethical and legal challenges.

Advancing Cardiomyocyte Maturation: Current Strategies and Promising Conductive Polymer-Based Approaches.

Cardiovascular diseases are a leading cause of mortality and pose a significant burden on healthcare systems worldwide. Despite remarkable progress in medical research, the development of effective cardiovascular drugs has been hindered by high failure rates and escalating costs. One contributing factor is the limited availability of mature cardiomyocytes (CMs) for accurate disease modeling and drug screening.

Highly Stable Low-Strain Flexible Sensors Based on Gold Nanoparticles/Silica Nanohelices.

Flexible strain sensors based on nanoparticle (NP) arrays show great potential for future applications such as electronic skin, flexible touchscreens, healthcare sensors, and robotics. However, even though these sensors can exhibit high sensitivity, they are usually not very stable under mechanical cycling and often exhibit large hysteresis, making them unsuitable for practical applications. In this work, strain sensors based on silica nanohelix (NH) arrays grafted with gold nanoparticles (AuNPs) can overcome these critical aspects.

Hollow ring-like flexible electrode architecture enabling subcellular multi-directional neural interfacing.

Implantable neural microelectrodes for recording and stimulating neural activity are critical for research in neuroscience and clinical neuroprosthetic applications. A current need exists for developing new technological solutions for obtaining highly selective and stealthy electrodes that provide reliable neural integration and maintain neuronal viability. This paper reports a novel Hollow Ring-like type electrode to sense and/or stimulate neural activity from three-dimensional neural networks.

Nanofibrous PEDOT-Carbon Composite on Flexible Probes for Soft Neural Interfacing.

In this study, we report a flexible implantable 4-channel microelectrode probe coated with highly porous and robust nanocomposite of poly (3,4-ethylenedioxythiophene) (PEDOT) and carbon nanofiber (CNF) as a solid doping template for high-performance neuronal recording and stimulation. A simple yet well-controlled deposition strategy was developed electrochemical polymerization technique to create a porous network of PEDOT and CNFs on a flexible 4-channel gold microelectrode probe. Different morphological and electrochemical characterizations showed that they exhibit remarkable and superior electrochemical properties, yielding microelectrodes combining high surface area, low impedance (16.

Microelectrodes from PEDOT-carbon nanofiber composite for high performance neural recording, stimulation and neurochemical sensing.

This present method describes a versatile approach for the electrochemical synthesis of a composite material of Poly (3,4-ethylenedioxythiophene) (PEDOT) and Carbon Nanofibers (CNFs) for neural interfaces and biosensing applications. Oxidized CNFs were utilized as dopants of PEDOT to prepare the composite coating through electrochemical deposition on microelectrodes arrays (MEA). The experimental results of this study showed that PEDOT:CNF microelectrodes exhibit remarkable electrochemical properties, combining low impedance, high surface area, high charge injection capability and reliable neurotransmitters monitoring using amperometric techniques.

Carbon nanofiber-PEDOT composite films as novel microelectrode for neural interfaces and biosensing.

A clear need exists for novel nanostructured materials that are capable to meet the performance criteria of a number of neuronal therapies including neural recording, stimulation and sensing of bioactive molecules at the electrode-tissue interface. By combining Poly (3,4-ethylenedioxythiophene) (PEDOT), with Carbon Nanofibers (CNFs), we demonstrate a versatile approach for the synthesis of a novel composite material PEDOT:CNF with remarkable electrochemical properties, combining low impedance, high surface area, high charge injection capability and reliable neurotransmitters monitoring using amperometric techniques. The oxidized CNFs were utilized as dopants of PEDOT to prepare the composite coatings through electrochemical deposition on neural microelectrodes arrays (MEA).

Unprecedented switching endurance affords for high-resolution surface temperature mapping using a spin-crossover film.

Temperature measurement at the nanoscale is of paramount importance in the fields of nanoscience and nanotechnology, and calls for the development of versatile, high-resolution thermometry techniques. Here, the working principle and quantitative performance of a cost-effective nanothermometer are experimentally demonstrated, using a molecular spin-crossover thin film as a surface temperature sensor, probed optically. We evidence highly reliable thermometric performance (diffraction-limited sub-µm spatial, µs temporal and 1 °C thermal resolution), which stems to a large extent from the unprecedented quality of the vacuum-deposited thin films of the molecular complex [Fe(HB(1,2,4-triazol-1-yl))] used in this work, in terms of fabrication and switching endurance (>10 thermal cycles in ambient air).

Recording local field potential and neuronal activity with tetrodes in epileptic patients.

Background: Recordings with tetrodes have proven to be more effective in isolating single neuron spiking activity than with single microwires. However, tetrodes have never been used in humans. We report on the characteristics, safety, compatibility with clinical intracranial recordings in epileptic patients, and performance, of a new type of hybrid electrode equipped with tetrodes.

Heat Capacity and Thermal Damping Properties of Spin-Crossover Molecules: A New Look at an Old Topic.

The thermally induced spin-crossover (SCO) phenomenon in transition metal complexes is an entropy-driven process, which has been extensively studied through calorimetric methods. Yet, the excess heat capacity associated with the molecular spin-state switching has never been explored for practical applications. Herein, the thermal damping effect of an SCO film is experimentally assessed by monitoring the transient heating response of SCO-coated metallic microwires, Joule-heated by current pulses.

A review on mechanical considerations for chronically-implanted neural probes.

This review intends to present a comprehensive analysis of the mechanical considerations for chronically-implanted neural probes. Failure of neural electrical recordings or stimulation over time has shown to arise from foreign body reaction and device material stability. It seems that devices that match most closely with the mechanical properties of the brain would be more likely to reduce the mechanical stress at the probe/tissue interface, thus improving body acceptance.

Spray-coated carbon nanotube carpets for creeping reduction of conducting polymer based artificial muscles.

During cyclic actuation, conducting polymer based artificial muscles are often creeping from the initial movement range. One of the likely reasons of such behaviour is unbalanced charging during conducting polymer oxidation and reduction. To improve the actuation reversibility and subsequently the long time performance of ionic actuators, we suggest using spray-coated carbon nanotube (CNT) carpets on the surface of the conducting polymer electrodes.

High Spatial Resolution Imaging of Transient Thermal Events Using Materials with Thermal Memory.

The working principle of a new kind of nanothermometer is experimentally demonstrated using bistable materials with thermal memory. This thermometry approach allows for acquiring sub-wavelength resolution images of fast, transient heating events.

Hybrid PVDF/PVDF-graft-PEGMA Membranes for Improved Interface Strength and Lifetime of PEDOT:PSS/PVDF/Ionic Liquid Actuators.

Unlabelled: The exploitation of soft conducting polymer-based actuators suffers from two main shortcomings: their short life cycle and the reproducibility of the fabrication techniques. The short life cycle usually results from the delamination of the components due to stresses at the interface during the actuation. In this work, to achieve strong adhesion to poly(3,4- ethylenedioxythiophene) poly(styrenesulfonate) (

Pedot: PSS) electrodes, the wetting properties of the surface of a polyvinylidene fluoride (PVDF) membrane are improved using argon-plasma-induced surface polymerization of poly(ethylene glycol) monomethyl ether methacrylate (PEGMA).

AFM imaging of molecular spin-state changes through quantitative thermomechanical measurements.

Quantitative atomic force microscopy is used in conjunction with microwire heaters for high-resolution imaging of the Young's modulus changes across the spin-state transition. When going from the high spin to the low spin state, a significant stiffening is observed.

Note: A scanning thermal probe microscope that operates in liquids.

We have developed a scanning thermal probe microscope that operates in liquid environments. The thermal sensor is a fluorescent particle glued at the end of a sharp tungsten tip. Since light emission is a strongly thermally sensitive effect, the measurement of the particle fluorescence variations allows the determination of the temperature.

Scanning thermal imaging by near-field fluorescence spectroscopy.

A scanning thermal microscope that uses a fluorescent particle as a temperature probe has been developed. The particle, made of a rare-earth ion-doped fluoride glass, is glued at the extremity of a sharp tungsten tip and scanned on the surface of an electronic device. The temperature of the device is determined by measuring the fluorescence spectrum of the particle at every point on the surface and by comparing the intensity variations of two emission lines.

Direct patterning of molecularly imprinted microdot arrays for sensors and biochips.

We have used fountain pen microlithography to deposit arrays of molecularly imprinted polymer microdots on flat substrates. We visualize analyte binding to the dots by fluorescence microscopy with the aid of fluorescein as a model analyte. Elution and readsorption of the analyte to the MIP dots were possible if the porosity of the dots was improved by a sacrificial polymeric porogen.