Long Noncoding RNA X-Inactive Specific Transcript (XIST) Promotes Osteogenic Differentiation of Periodontal Ligament Stem Cells by Sponging MicroRNA-214-3p.

BACKGROUND Osteogenic differentiation of periodontal ligament stem cells (PDLSCs) is associated with periodontitis. It has been reported that long noncoding RNA X-inactive specific transcript (lncRNA XIST) is upregulated and microRNA-214-3p (miR-214-3p) is downregulated in PDLSCs after osteogenic induction. However, whether XIST is involved in osteogenic differentiation of PDLSCs via miR-214-3p has not been reported. MATERIAL AND METHODS The protein expressions of osteogenic markers alkaline phosphatase (ALP), osteocalcin (OCN), and runt-related transcription factor 2 (RUNX2) were examined by Western blot. The levels of miR-214-3p and XIST were determined by qRT-PCR. The relationship between miR-214-3p and XIST was evaluated by luciferase reporter, RNA immunoprecipitation, and RNA pulldown assays. RESULTS We found that XIST was increased and miR-214-3p was decreased in PDLSCs after osteogenic stimulation. Silencing of XIST decreased the protein expressions of ALP, OCN, and RUNX2, and also decreased ALP activity. Higher miR-214-3p levels also inhibited osteogenic differentiation of PDLSCs. XIST interacted with miR-214-3p and depletion of miR-214-3p mitigated XIST absence-mediated suppression of osteogenic differentiation. CONCLUSIONS XIST participates in osteogenic differentiation of PDLSCs by sponging miR-214-3p.

A Wearable Transient Pressure Sensor Made with MXene Nanosheets for Sensitive Broad-Range Human-Machine Interfacing.

Flexible and degradable pressure sensors have received tremendous attention for potential use in transient electronic skins, flexible displays, and intelligent robotics due to their portability, real-time sensing performance, flexibility, and decreased electronic waste and environmental impact. However, it remains a critical challenge to simultaneously achieve a high sensitivity, broad sensing range (up to 30 kPa), fast response, long-term durability, and robust environmental degradability to achieve full-scale biomonitoring and decreased electronic waste. MXenes, which are two-dimensional layered structures with a large specific surface area and high conductivity, are widely employed in electrochemical energy devices. Here, we present a highly sensitive, flexible, and degradable pressure sensor fabricated by sandwiching porous MXene-impregnated tissue paper between a biodegradable polylactic acid (PLA) thin sheet and an interdigitated electrode-coated PLA thin sheet. The flexible pressure sensor exhibits high sensitivity with a low detection limit (10.2 Pa), broad range (up to 30 kPa), fast response (11 ms), low power consumption (10-8 W), great reproducibility over 10 000 cycles, and excellent degradability. It can also be used to predict the potential health status of patients and act as an electronic skin (E-skin) for mapping tactile stimuli, suggesting potential in personal healthcare monitoring, clinical diagnosis, and next-generation artificial skins.

Flexible 3D Porous MXene Foam for High-Performance Lithium-Ion Batteries.

2D transition-metal carbides and nitrides, named MXenes, are promising materials for energy storage, but suffer from aggregation and restacking of the 2D nanosheets, which limits their electrochemical performance. In order to overcome this problem and realize the full potential of MXene nanosheets, a 3D MXene foam with developed porous structure is established via a simple sulfur-template method, which is freestanding, flexible, and highly conductive, and can be directly used as the electrode in lithium-ion batteries. The 3D porous architecture of the MXene foam offers massive active sites to enhance the lithium storage capacity. Moreover, its foam structure facilitates electrolyte infiltration for fast Li+ transfer. As a result, this flexible 3D porous MXene foam exhibits significantly enhanced capacity of 455.5 mAh g-1 at 50 mA g-1 , excellent rate performance (101 mAh g-1 at 18 A g-1 ), and superior ultralong-term cycle stability (220 mAh g-1 at 1 A g-1 after 3500 cycles). This work not only demonstrates the great superiority of the 3D porous MXene foam but also proposes the sulfur-template method for controllable constructing of the 3D foam from 2D nanosheets at a relatively low temperature.

A Flexible Stretchable Hydrogel Electrolyte for Healable All-in-One Configured Supercapacitors.

The development of integrated high-performance supercapacitors with all-in-one configuration, excellent flexibility and autonomously intrinsic self-healability, and without the extra healable film layers, is still tremendously challenging. Compared to the sandwich-like laminated structures of supercapacitors with augmented interfacial contact resistance, the flexible healable integrated supercapacitor with all-in-one structure could theoretically improve their interfacial contact resistance and energy densities, simplify the tedious device assembly process, prolong the lifetime, and avoid the displacement and delamination of multilayered configurations under deformations. Herein, a flexible healable all-in-one configured supercapacitor with excellent flexibility and reliable self-healing ability by avoiding the extra healable film substrates and the postassembled sandwich-like laminated structures is developed. The healable all-in-one configured supercapacitor is prepared from in situ polymerization and deposition of nanocomposites electrode materials onto the two-sided faces of the self-healing hydrogel electrolyte separator. The self-healing hydrogel film is obtained from the physically crosslinked hydrogel with enormous hydrogen bonds, which can endow the healable capability through dynamic hydrogen bonding. The assembled all-in-one configured supercapacitor exhibits enhanced capacitive performance, good cycling stability, reliable self-healing capability, and excellent flexibility. It holds broad prospects for obtaining various flexible healable all-in-one configured supercapacitors for working as portable energy storage devices in wearable electronics.

A Flexible Wearable Pressure Sensor with Bioinspired Microcrack and Interlocking for Full-Range Human-Machine Interfacing.

Flexible wearable pressure sensors have drawn tremendous interest for various applications in wearable healthcare monitoring, disease diagnostics, and human-machine interaction. However, the limited sensing range (<10%), low sensing sensitivity at small strains, limited mechanical stability at high strains, and complicated fabrication process restrict the extensive applications of these sensors for ultrasensitive full-range healthcare monitoring. Herein, a flexible wearable pressure sensor is presented with a hierarchically microstructured framework combining microcrack and interlocking, bioinspired by the crack-shaped mechanosensory systems of spiders and the wing-locking sensing systems of beetles. The sensor exhibits wide full-range healthcare monitoring under strain deformations of 0.2-80%, fast response/recovery time (22 ms/20 ms), high sensitivity, the ultrasensitive loading sensing of a feather (25 mg), the potential to predict the health of patients with early-stage Parkinson's disease with the imitated static tremor, and excellent reproducibility over 10 000 cycles. Meanwhile, the sensor can be assembled as smart artificial electronic skins (E-skins) for simultaneously mapping the pressure distribution and shape of touching sensing. Furthermore, it can be attached onto the legs of a smart robot and coupled to a wireless transmitter for wirelessly monitoring human-motion interactivities.

Stretchable Electronic Sensors of Nanocomposite Network Films for Ultrasensitive Chemical Vapor Sensing.

A stretchable, transparent, and body-attachable chemical sensor is assembled from the stretchable nanocomposite network film for ultrasensitive chemical vapor sensing. The stretchable nanocomposite network film is fabricated by in situ preparation of polyaniline/MoS2 (PANI/MoS2 ) nanocomposite in MoS2 suspension and simultaneously nanocomposite deposition onto prestrain elastomeric polydimethylsiloxane substrate. The assembled stretchable electronic sensor demonstrates ultrasensitive sensing performance as low as 50 ppb, robust sensing stability, and reliable stretchability for high-performance chemical vapor sensing. The ultrasensitive sensing performance of the stretchable electronic sensors could be ascribed to the synergistic sensing advantages of MoS2 and PANI, higher specific surface area, the reliable sensing channels of interconnected network, and the effectively exposed sensing materials. It is expected to hold great promise for assembling various flexible stretchable chemical vapor sensors with ultrasensitive sensing performance, superior sensing stability, reliable stretchability, and robust portability to be potentially integrated into wearable electronics for real-time monitoring of environment safety and human healthcare.

Sulfophenyl-Functionalized Reduced Graphene Oxide Networks on Electrospun 3D Scaffold for Ultrasensitive NO2 Gas Sensor.

Ultrasensitive room temperature real-time NO2 sensors are highly desirable due to potential threats on environmental security and personal respiratory. Traditional NO2 gas sensors with highly operated temperatures (200-600 °C) and limited reversibility are mainly constructed from semiconducting oxide-deposited ceramic tubes or inter-finger probes. Herein, we report the functionalized graphene network film sensors assembled on an electrospun three-dimensional (3D) nanonetwork skeleton for ultrasensitive NO2 sensing. The functional 3D scaffold was prepared by electrospinning interconnected polyacrylonitrile (PAN) nanofibers onto a nylon window screen to provide a 3D nanonetwork skeleton. Then, the sulfophenyl-functionalized reduced graphene oxide (SFRGO) was assembled on the electrospun 3D nanonetwork skeleton to form SFRGO network films. The assembled functionalized graphene network film sensors exhibit excellent NO2 sensing performance (10 ppb to 20 ppm) at room temperature, reliable reversibility, good selectivity, and better sensing cycle stability. These improvements can be ascribed to the functionalization of graphene with electron-withdrawing sulfophenyl groups, the high surface-to-volume ratio, and the effective sensing channels from SFRGO wrapping onto the interconnected 3D scaffold. The SFRGO network-sensing film has the advantages of simple preparation, low cost, good processability, and ultrasensitive NO2 sensing, all advantages that can be utilized for potential integration into smart windows and wearable electronic devices for real-time household gas sensors.

High-Performance Water Electrolysis System with Double Nanostructured Superaerophobic Electrodes.

Catalysts screening and structural optimization are both essential for pursuing a high-efficient water electrolysis system (WES) with reduced energy supply. This study demonstrates an advanced WES with double superaerophobic electrodes, which are achieved by constructing a nanostructured NiMo alloy and NiFe layered double hydroxide (NiFe-LDH) films for hydrogen evolution and oxygen evolution reactions, respectively. The superaerophobic property gives rise to significantly reduced adhesion forces to gas bubbles and thereby accelerates the hydrogen and oxygen bubble releasing behaviors. Benefited from these metrics and the high intrinsic activities of catalysts, this WES affords an early onset potential (≈1.5 V) for water splitting and ultrafast catalytic current density increase (≈0.83 mA mV(-1) ), resulting in ≈2.69 times higher performance compared to the commercial Pt/C and IrO2 /C catalysts based counterpart under 1.9 V. Moreover, enhanced performance at high temperature as well as prominent stability further demonstrate the practical application of this WES.

Flexible Transparent Electronic Gas Sensors.

Flexible and transparent electronic gas sensors capable of real-time, sensitive, and selective analysis at room-temperature, have gained immense popularity in recent years for their potential to be integrated into various smart wearable electronics and display devices. Here, recent advances in flexible transparent sensors constructed from semiconducting oxides, carbon materials, conducting polymers, and their nanocomposites are presented. The sensing material selection, sensor device construction, and sensing mechanism of flexible transparent sensors are discussed in detail. The critical challenges and future development associated with flexible and transparent electronic gas sensors are presented. Smart wearable gas sensors are believed to have great potential in environmental monitoring and noninvasive health monitoring based on disease biomarkers in exhaled gas.

Healable, Transparent, Room-Temperature Electronic Sensors Based on Carbon Nanotube Network-Coated Polyelectrolyte Multilayers.

Transparent and conductive film based electronics have attracted substantial research interest in various wearable and integrated display devices in recent years. The breakdown of transparent electronics prompts the development of transparent electronics integrated with healability. A healable transparent chemical gas sensor device is assembled from layer-by-layer-assembled transparent healable polyelectrolyte multilayer films by developing effective methods to cast transparent carbon nanotube (CNT) networks on healable substrates. The healable CNT network-containing film with transparency and superior network structures on self-healing substrate is obtained by the lateral movement of the underlying self-healing layer to bring the separated areas of the CNT layer back into contact. The as-prepared healable transparent film is assembled into healable transparent chemical gas sensor device for flexible, healable gas sensing at room temperature, due to the 1D confined network structure, relatively high carrier mobility, and large surface-to-volume ratio. The healable transparent chemical gas sensor demonstrates excellent sensing performance, robust healability, reliable flexibility, and good transparency, providing promising opportunities for developing flexible, healable transparent optoelectronic devices with the reduced raw material consumption, decreased maintenance costs, improved lifetime, and robust functional reliability.

Transparent conducting films of hierarchically nanostructured polyaniline networks on flexible substrates for high-performance gas sensors.

Transparent chemical gas sensors are assembled from a transparent conducting film of hierarchically nanostructured polyaniline (PANI) networks fabricated on a flexible PET substrate, by coating silver nanowires (Ag NWs) followed by the in situ polymerization of aniline near the sacrificial Ag NW template. The sensor exhibits enhanced gas sensing performance at room temperature in both sensitivity and selectivity to NH3 compared to pure PANI film.

Flexible Transparent Films Based on Nanocomposite Networks of Polyaniline and Carbon Nanotubes for High-Performance Gas Sensing.

A flexible, transparent, chemical gas sensor is assembled from a transparent conducting film of carbon nanotube (CNT) networks that are coated with hierarchically nanostructured polyaniline (PANI) nanorods. The nanocomposite film is synthesized by in-situ, chemical oxidative polymerization of aniline in a functional multiwalled CNT (FMWCNT) suspension and is simultaneously deposited onto a flexible polyethylene terephthalate (PET) substrate. An as-prepared flexible transparent chemical gas sensor exhibits excellent transparency of 85.0% at 550 nm using the PANI/FMWCNT nanocomposite film prepared over a reaction time of 8 h. The sensor also shows good flexibility, without any obvious decrease in performance after 500 bending/extending cycles, demonstrating high-performance, portable gas sensing at room temperature. This superior performance could be attributed to the improved electron transport and collection due to the CNTs, resulting in reliable and efficient sensing, as well as the high surface-to-volume ratio of the hierarchically nanostructured composites. The excellent transparency, improved sensing performance, and superior flexibility of the device, may enable the integration of this simple, low-cost, gas sensor into handheld flexible transparent electronic circuitry and optoelectronic devices.

Controllable Assembly and Separation of Colloidal Nanoparticles through a One-Tube Synthesis Based on Density Gradient Centrifugation.

Self-assembly of gold nanoparticles into one-dimensional (1D) nanostructures with finite primary units was achieved by introducing a thin salt (NaCl) solution layer into density gradient before centrifugation. The electrostatic interactions between Au nanoparticles would be affected and cause 1D assembly upon passing through the salt layer. A negatively charged polymer such as poly(acrylic acid) was used as an encapsulation/stabilization layer to help the formation of 1D Au assemblies, which were subsequently sorted according to unit numbers at succeeding separation zones. A centrifugal field was introduced as the external field to overcome the random Brownian motion of NPs and benefit the assembly effect. Such a facile "one-tube synthesis" approach couples assembly and separation in one centrifuge tube by centrifuging once. The method can be tuned by changing the concentration of interference salt layer, encapsulation layer, and centrifugation rate. Furthermore, positively charged fluorescent polymers such as perylenediimide-poly(N,N-diethylaminoethyl methacrylate) could encapsulate the assemblies to give tunable fluorescence properties.

Graphene carrier for magneto-controllable bioelectrocatalysis.

A magnetically driven fuel-free graphene carrier loaded with redox-active cargo-ferrocene as an electron mediator is fabricated for magneto-controllable bioelectrocatalysis. The activation and deactivation of redox-active cargo's redox activity by magnetically driven positioning of the graphene carrier with loaded ferrocene near and away from the conductive support can be employed for magneto-switchable bioelectrocatalyzed oxidation of glucose by glucose oxidase between active and inactive electrocatalytic states, respectively.

Flexible Conformally Bioadhesive MXene Hydrogel Electronics for Machine Learning-Facilitated Human-Interactive Sensing.

Wearable epidermic electronics assembled from conductive hydrogels are attracting various research attention for their seamless integration with human body for conformally real-time health monitoring, clinical diagnostics and medical treatment, and human-interactive sensing. Nevertheless, it remains a tremendous challenge to simultaneously achieve conformally bioadhesive epidermic electronics with remarkable self-adhesiveness, reliable ultraviolet (UV) protection ability, and admirable sensing performance for high-fidelity epidermal electrophysiological signals monitoring, along with timely photothermal therapeutic performances after medical diagnostic sensing, as well as efficient antibacterial activity and reliable hemostatic effect for potential medical therapy. Herein, a conformally bioadhesive hydrogel-based epidermic sensor, featuring superior self-adhesiveness and excellent UV-protection performance, is developed by dexterously assembling conducting MXene nanosheets network with biological hydrogel polymer network for conformally stably attaching onto human skin for high-quality recording of various epidermal electrophysiological signals with high signal-to-noise ratios (SNR) and low interfacial impedance for intelligent medical diagnosis and smart human-machine interface. Moreover, a smart sign language gesture recognition platform based on collected electromyogram (EMG) signals is designed for hassle-free communication with hearing-impaired people with the help of advanced machine learning algorithms. Meanwhile, the bioadhesive MXene hydrogel possesses reliable antibacterial capability, excellent biocompatibility, and effective hemostasis properties for promising bacterial-infected wound bleeding.

Flexible Bioinspired Healable Antibacterial Electronics for Intelligent Human-Machine Interaction Sensing.

Flexible electronic sensors are receiving numerous research interests for their potential in electronic skins (e-skins), wearable human-machine interfacing, and smart diagnostic healthcare sensing. However, the preparation of multifunctional flexible electronics with high sensitivity, broad sensing range, fast response, efficient healability, and reliable antibacterial capability is still a substantial challenge. Herein, bioinspired by the highly sensitive human skin microstructure (protective epidermis/spinous sensing structure/nerve conduction network), a skin bionic multifunctional electronics is prepared by face-to-face assembly of a newly prepared healable, recyclable, and antibacterial polyurethane elastomer matrix with conductive MXene nanosheets-coated microdome array after ingenious templating method as protective epidermis layer/sensing layer, and an interdigitated electrode as signal transmission layer. The polyurethane elastomer matrix functionalized with triple dynamic bonds (reversible hydrogen bonds, oxime carbamate bonds, and copper (II) ion coordination bonds) is newly prepared, demonstrating excellent healability with highly healing efficiency, robust recyclability, and reliable antibacterial capability, as well as good biocompatibility. Benefiting from the superior mechanical performance of the polyurethane elastomer matrix and the unique skin bionic microstructure of the sensor, the as-assembled flexible electronics exhibit admirable sensing performances featuring ultrahigh sensitivity (up to 1573.05 kPa-1 ), broad sensing range (up to 325 kPa), good reproducibility, the fast response time (≈4 ms), and low detection limit (≈0.98 Pa) in diagnostic human healthcare monitoring, excellent healability, and reliable antibacterial performance.

A Flexible Skin Bionic Thermally Comfortable Wearable for Machine Learning-Facilitated Ultrasensitive Sensing.

Tremendous popularity is observed for multifunctional flexible electronics with appealing applications in intelligent electronic skins, human-machine interfaces, and healthcare sensing. However, the reported sensing electronics, mostly can hardly provide ultrasensitive sensing sensitivity, wider sensing range, and robust cycling stability simultaneously, and are limited of efficient heat conduction out from the contacted skin interface after wearing flexible electronics on human skin to satisfy thermal comfort of human skin. Inspired from the ultrasensitive tactile perception microstructure (epidermis/spinosum/signal transmission) of human skin, a flexible comfortably wearable ultrasensitive electronics is hereby prepared from thermal conductive boron nitride nanosheets-incorporated polyurethane elastomer matrix with MXene nanosheets-coated surface microdomes as epidermis/spinosum layers assembled with interdigitated electrode as sensing signal transmission layer. It demonstrates appealing sensing performance with ultrasensitive sensitivity (≈288.95 kPa-1), up to 300 kPa sensing range, and up to 20 000 sensing cycles from obvious contact area variation between microdome microstructures and the contact electrode under external compression. Furthermore, the bioinspired electronics present advanced thermal management by timely efficient thermal dissipation out from the contacted skin surface to meet human skin thermal comfort with the incorporated thermal conductive boron nitride nanosheets. Thus, it is vitally promising in wearable artificial electronic skins, intelligent human-interactive sensing, and personal health management.

Self-Powered Resilient Porous Sensors with Thermoelectric Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) and Carbon Nanotubes for Sensitive Temperature and Pressure Dual-Mode Sensing.

Portable and wearable dual-mode sensors that can simultaneously detect multiple stimuli are essential for emerging artificial intelligence applications, and most efforts are devoted to exploring pressure-sensing devices. It is still challenging to integrate temperature and pressure-sensing functions into one sensor without the requirement for complex decoupling processes. Herein, we develop a self-powered and multifunctional dual-mode sensor by dip-coating melamine sponge with both poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and carboxylated single-walled carbon nanotubes (CNTs). By integrating thermoelectric and conductive PEDOT:PSS/CNT components with the hydrophilic and resilient porous sponge, the resultant sensor is efficient in independently detecting temperature and pressure changes. The temperature and pressure stimuli can be independently converted to voltage and electrical resistance signals on the basis of the Seebeck and piezoresistive effects, respectively. The sensor exhibits a high Seebeck coefficient of 35.9 µV K-1 with a minimum temperature detection limit of 0.4 K and a pressure sensitivity of -3.35% kPa-1 with a minimum pressure detection limit of 4 Pa. Interestingly, the sensor can also be self-powered upon illumination. These multi-functionalities make the sensor a promising tool for applications in electronic skin, soft robots, solar energy conversion, and personal health monitoring.

Healable, Degradable, and Conductive MXene Nanocomposite Hydrogel for Multifunctional Epidermal Sensors.

Conductive hydrogels have emerged as promising material candidates for epidermal sensors due to their similarity to biological tissues, good wearability, and high accuracy of information acquisition. However, it is difficult to simultaneously achieve conductive hydrogel-based epidermal sensors with reliable healability for long-term usage, robust mechanical property, environmental degradability for decreased electronic waste, and sensing capability of the physiological stimuli and the electrophysiological signals. Herein, we propose the synthesis strategy of a multifunctional epidermal sensor based on the highly stretchable, self-healing, degradable, and biocompatible nanocomposite hydrogel, which is fabricated from the conformal coating of a MXene (Ti3C2Tx) network by the hydrogel polymer networks involving poly(acrylic acid) and amorphous calcium carbonate. The epidermal sensor can be employed to sensitively detect human motions with the fast response time (20 ms) and to serve as electronic skins for wirelessly monitoring the electrophysiological signals (such as the electromyogram and electrocardiogram signals). Meanwhile, the multifunctional epidermal sensor could be degraded in phosphate buffered saline solution, which could not cause any pollution to the environment. This line of research work sheds light on the fabrication of the healable, degradable, and electrophysiological signal-sensitive conductive hydrogel-based epidermal sensors with potential applications in human-machine interactions, healthy diagnosis, and smart robot prosthesis devices.

Breathable Ti3C2Tx MXene/Protein Nanocomposites for Ultrasensitive Medical Pressure Sensor with Degradability in Solvents.

Flexible, breathable, and degradable pressure sensors with excellent sensing performance are drawing tremendous attention for various practical applications in wearable artificial skins, healthcare monitoring, and artificial intelligence due to their flexibility, breathability, lightweight, decreased electronic rubbish, and environmentally friendly impact. However, traditional plastic or elastomer substrates with impermeability, uncomfortableness, mechanical mismatches, and nondegradability greatly restricted their practical applications. Therefore, the fabrication of such pressure sensors with high flexibility, facile degradability, and breathability is still a critical challenge and highly desired. Herein, we present a wearable, breathable, degradable, and highly sensitive MXene/protein nanocomposites-based pressure sensor. The fabricated MXene/protein-based pressure sensor is assembled from a breathable conductive MXene coated silk fibroin nanofiber (MXene-SF) membrane and a silk fibroin nanofiber membrane patterned with a MXene ink-printed (MXene ink-SF) interdigitated electrode, which can serve as the sensing layer and the electrode layer, respectively. The assembled pressure sensor exhibits a wide sensing range (up to 39.3 kPa), high sensitivity (298.4 kPa-1 for 1.4-15.7 kPa; 171.9 kPa-1 for 15.7-39.3 kPa), fast response/recovery time (7/16 ms), reliable breathability, excellent cycling stability over 10 000 cycles, good biocompatibility, and robust degradability. Furthermore, it shows great sensing performance in monitoring human psychological signals, acting as an artificial skin for the quantitative illustration of pressure distribution, and wireless biomonitoring in real time. Considering the biodegradable and breathable features, the sensor may become promising to find potential applications in smart electronic skins, human motion detection, disease diagnosis, and human-machine interaction.