Neural tissue engineering has emerged as a promising field that aims to create functional neural tissue for therapeutic applications, drug screening, and disease modelling. It is becoming evident in the literature that this goal requires development of three-dimensional (3D) constructs that can mimic the complex microenvironment of native neural tissue, including its biochemical, mechanical, physical, and electrical properties. These 3D models can be broadly classified as self-assembled models, which include spheroids, organoids, and assembloids, and engineered models, such as those based on decellularized or polymeric scaffolds.
View Article and Find Full Text PDFPlatinum (Pt) is the metal of choice for electrodes in implantable neural prostheses like the cochlear implants, deep brain stimulating devices, and brain-computer interfacing technologies. However, it is well known since the 1970s that Pt dissolution occurs with electrical stimulation. More recent clinical and in vivo studies have shown signs of corrosion in explanted electrode arrays and the presence of Pt-containing particulates in tissue samples.
View Article and Find Full Text PDFIntegration of bioelectronic devices in clinical practice is expanding rapidly, focusing on conditions ranging from sensory to neurological and mental health disorders. While platinum (Pt) electrodes in neuromodulation devices such as cochlear implants and deep brain stimulators have shown promising results, challenges still affect their long-term performance. Key among these are electrode and device longevity in vivo, and formation of encapsulating fibrous tissue.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2023
Fibrous tissue encapsulation can impact the performance of bioelectrodes following implantation. For example, significant increases in electrode impedance can occur within four weeks post-implantation. A key limitation hindering the understanding of host response-mediated impedance change is the reliance on animal models or complex in vitro cell cultures for electrode testing.
View Article and Find Full Text PDFOptical-electrode (optrode) arrays use light to modulate excitable biological tissues and/or transduce bioelectrical signals into the optical domain. Light offers several advantages over electrical wiring, including the ability to encode multiple data channels within a single beam. This approach is at the forefront of innovation aimed at increasing spatial resolution and channel count in multichannel electrophysiology systems.
View Article and Find Full Text PDFMany different types of inorganic materials are processed into nano/microparticles for medical utilization. The impact of selected key characteristics of these particles, including size, shape, and surface chemistries, on biological systems, is frequently studied in clinical contexts. However, one of the most important basic characteristics of these particles, their density, is yet to be investigated.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2022
The application of transparent conductive films to flexible biomedical optoelectronics is limited by stringent requirements on the candidate materials' electromechanical and optical properties as well as their biological performance. Thin films of graphene and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) are sought as mechanically flexible alternatives to traditional indium tin oxide (ITO). However, they require more understanding of their suitability for biomedical optoelectronic devices in terms of transmission behavior and electromechanical stability.
View Article and Find Full Text PDFGallium (Ga) compounds, as the source of Ga ions (Ga), have been historically used as anti-inflammatories. Currently, the widely accepted mechanisms of the anti-inflammatory effects for Ga are rationalized on the basis of their similarities to ferric ions (Fe), which permits Ga to bind with Fe-binding proteins and subsequently disturbs the Fe homeostasis in the immune cells. Here in contrast to the classic views, our study presents the mechanisms of Ga as anti-inflammatory by delivering Ga nanodroplets (GNDs) into lipopolysaccharide-induced macrophages and exploring the processes.
View Article and Find Full Text PDFTransforming natural resources to energy sources, such as converting CH to H and carbon, at high efficiency and low cost is crucial for many industries and environmental sustainability. The high temperature requirement of CH conversion regarding many of the current methods remains a critical bottleneck for their practical uptake. Here we report an approach based on gallium (Ga) liquid metal droplets, Ni(OH) cocatalysts, and mechanical energy input that offers low-temperature and scalable CH conversion into H and carbon.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2021
Molybdenum dioxide (MoO), considering its near-metallic conductivity and surface plasmonic properties, is a great material for electronics, energy storage devices and biosensing. Yet to this day, room-temperature synthesis of large area MoO, which allows deposition on arbitrary substrates, has remained a challenge. Due to their reactive interfaces and specific solubility conditions, gallium-based liquid metal alloys offer unique opportunities for synthesizing materials that can meet these challenges.
View Article and Find Full Text PDFLow melting point eutectic systems, such as the eutectic gallium-indium (EGaIn) alloy, offer great potential in the domain of nanometallurgy; however, many of their interfacial behaviors remain to be explored. Here, a compositional change of EGaIn nanoalloys triggered by polydopamine (PDA) coating is demonstrated. Incorporating PDA on the surface of EGaIn nanoalloys renders core-shell nanostructures that accompany Ga-In phase separation within the nanoalloys.
View Article and Find Full Text PDFA green carbon capture and conversion technology offering scalability and economic viability for mitigating CO emissions is reported. The technology uses suspensions of gallium liquid metal to reduce CO into carbonaceous solid products and O at near room temperature. The nonpolar nature of the liquid gallium interface allows the solid products to instantaneously exfoliate, hence keeping active sites accessible.
View Article and Find Full Text PDFThe emergence of three-dimensional (3D) printing promises a disruption in the design and on-demand fabrication of smart structures in applications ranging from functional devices to human organs. However, the scale at which 3D printing excels is within macro- and microlevels and principally lacks the spatial ordering of building blocks at nanolevels, which is vital for most multifunctional devices. Herein, we employ liquid crystal (LC) inks to bridge the gap between the nano- and microscales in a single-step 3D printing.
View Article and Find Full Text PDFAlthough it remains unexplored, the direct synthesis and expulsion of metals from alloys can offer many opportunities. Here, such a phenomenon is realized electrochemically by applying a polarizing voltage signal to liquid alloys. The signal induces an abrupt interfacial perturbation at the Ga-based liquid alloy surface and results in an unrestrained discharge of minority elements, such as Sn, In, and Zn, from the liquid alloy.
View Article and Find Full Text PDFRoom-temperature synthesis of 2D graphitic materials (2D-GMs) remains an elusive aim, especially with electrochemical means. Here, it is shown that liquid metals render this possible as they offer catalytic activity and an ultrasmooth templating interface that promotes Frank-van der Merwe regime growth, while allowing facile exfoliation due to the absence of interfacial forces as a nonpolar liquid. The 2D-GMs are formed at low onset potential and can be in situ doped depending on the choice of organic precursors and the electrochemical set-up.
View Article and Find Full Text PDFAntibiotic resistance has made the treatment of biofilm-related infections challenging. As such, the quest for next-generation antimicrobial technologies must focus on targeted therapies to which pathogenic bacteria cannot develop resistance. Stimuli-responsive therapies represent an alternative technological focus due to their capability of delivering targeted treatment.
View Article and Find Full Text PDFThe original version of this Article contained errors in the author affiliations. Affiliation 1 incorrectly read 'School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2031, Australia' and affiliation 4 incorrectly read 'School of Engineering, RMIT University, Melbourne, VIC 3001, Australia.' This has now been corrected in both the PDF and HTML versions of the Article.
View Article and Find Full Text PDFNegative carbon emission technologies are critical for ensuring a future stable climate. However, the gaseous state of CO does render the indefinite storage of this greenhouse gas challenging. Herein, we created a liquid metal electrocatalyst that contains metallic elemental cerium nanoparticles, which facilitates the electrochemical reduction of CO to layered solid carbonaceous species, at a low onset potential of -310 mV vs CO/C.
View Article and Find Full Text PDFFabrication of flexible and free-standing graphene-fiber- (GF-) based microelectrode arrays with a thin platinum coating, acting as a current collector, results in a structure with low impedance, high surface area, and excellent electrochemical properties. This modification results in a strong synergistic effect between these two constituents leading to a robust and superior hybrid material with better performance than either graphene electrodes or Pt electrodes. The low impedance and porous structure of the GF results in an unrivalled charge injection capacity of 10.
View Article and Find Full Text PDFWe report the synthesis of centimeter sized ultrathin GaN and InN. The synthesis relies on the ammonolysis of liquid metal derived two-dimensional (2D) oxide sheets that were squeeze-transferred onto desired substrates. Wurtzite GaN nanosheets featured typical thicknesses of 1.
View Article and Find Full Text PDFSilicon-based impurities are ubiquitous in natural graphite. However, their role as a contaminant in exfoliated graphene and their influence on devices have been overlooked. Herein atomic resolution microscopy is used to highlight the existence of silicon-based contamination on various solution-processed graphene.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2018
The family of crystals constituting covalently bound strings, held together by van der Waals forces, can be exfoliated into smaller entities, similar to crystals made of van der Waals sheets. Depending on the anisotropy of such crystals, as well as the spacing between their strings in each direction, van der Waals sheets or ribbons can be obtained after the exfoliation process. In this work, we demonstrate that ultrathin nanoribbons of bismuth sulfide (BiS) can be synthesized via a high-power sonication process.
View Article and Find Full Text PDFDeficits in neurite outgrowth and synaptogenesis have been recognized as an underlying developmental aetiology of psychosis. Electrical stimulation promotes neuronal induction including neurite outgrowth and branching. However, the effect of electrical stimulation using 3D electrodes on neurite outgrowth and synaptogenesis has not been explored.
View Article and Find Full Text PDFDeficits in neurite outgrowth, possibly involving dysregulation of risk genes neuregulin-1 (NRG1) and disrupted in schizophrenia 1 (DISC1) have been implicated in psychiatric disorders including schizophrenia. Electrical stimulation using conductive polymers has been shown to stimulate neurite outgrowth of differentiating human neural stem cells. This study investigated the use of the electroactive conductive polymer polypyrrole (Ppy) to counter impaired neurite outgrowth of primary pre-frontal cortical (PFC) neurons from NRG1-knock out (NRG1-KO) and DISC1-locus impairment (DISC1-LI) mice.
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