Direct 3D printing of triple-responsive nanocomposite hydrogel microneedles for controllable drug delivery.

Hydrogel microneedle patches have emerged as promising platforms for painless, minimally invasive, safe, and portable transdermal drug administration. However, the conventional mold-based fabrication processes and inherent single-functionality of such microneedles present significant hurdles to broader implementation. Herein, we have developed a novel approach utilizing a precursor solution of robust nanocomposite hydrogels to formulate photo-printable inks suitable for the direct 3D printing of high-precision, triple-responsive hydrogel microneedle patches through digital light processing (DLP) technology. The ink formulation comprises four functionally diverse monomers including 2-(dimethylamino)ethyl methacrylate, N-isopropylacrylamide, acrylic acid, and acrylamide, which were crosslinked by aluminum hydroxide nanoparticles (AH NPs) acting as both reinforcing agents and crosslinking centers. This results in the formation of a nanocomposite hydrogel characterized by exceptional mechanical strength, an essential attribute for the 3D printing of hydrogel microneeedle patches. Furthermore, this innovative 3D printing strategy facilitates facile customization of microneedle geometry and patch dimensions. As a proof-of-concept, we employed the fabricated hydrogel microneedles for transdermal delivery of bovine serum albumin (BSA). Importantly, these hydrogel microneedles displayed no cytotoxic effects and exhibited triple sensitivity to pH, temperature and glucose levels, thereby enabling more precise on-demand drug delivery. This study provides a universal method for the rapid fabrication of hydrogel microneedles with smart responsiveness for transdermal drug delivery applications.

Comparative transcriptomics revealed the ecological trap effect of linearly polarized light on Oratosquilla oratoria.

Although polarized light can assist many animals in performing special visual tasks, current polarized light pollution (PLP) caused by urban construction has been shown to induce maladaptive behaviors of PL-sensitive animals and change ecological interactions. However, the underlying mechanisms remain unclear. Our previous work hypothesized that linearly polarized light (LPL) is an ecological trap for Oratosquilla oratoria, a common Stomatopoda species in the China Sea. Here we explored the underlying negative effects of artificially LPL on O. oratoria based on comparative transcriptomics. We identified 3616 differentially expressed genes (DEGs) in O. oratoria compound eyes continuous exposed to natural light (NL) and LPL scenarios. In comparison with the NL scenario, a total of 1972 up- and 1644 down- regulated genes were obtained from the O. oratoria compound eyes under LPL scenario, respectively. Furthermore, we performed functional annotation of those DEGs described above and identified 65 DEGs related to phototransduction, reproduction, immunity, and synapse. Based on the functional information, we suspected that continuous LPL exposure could block the light transmission, disrupt the reproductive process, and lead to the progressive failure of the immune response of O. oratoria. In conclusion, this study is the first to systematically describe the negative effects of artificial LPL exposure on O. oratoria at the genetic level, and it can improve the biological conservation theory behind PLP.

Construction of Heterojunction-Rich Metal Nitrides Porous Nanosheets Electrocatalyst for Alkaline Water/Seawater Splitting at Large Current Density.

The exploiting electrocatalysts for water/seawater electrolysis with remarkable activity and outstanding durability at industrial grade current density remains a huge challenge. Herein, CoMoNx and Fe-doped CoMoNx nanosheet arrays are in-situ grown on Ni foam, which possess plentiful holes, multilevel heterostructure, and lavish Co5.47 N/MoN@NF and Fe-Co5.47 N/MoN@NF interfaces. They require low overpotentials of 213 and 296 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under alkaline media to achieve current density of 800 mA cm-2 , respectively, and both possess low Tafel slopes (51.1 and 49.1 mV dec-1 ) and undiminished stability over 80 h. Moreover, the coupled Co5.47 N/MoN@NF and Fe-Co5.47 N/MoN@NF electrolyzer requires low voltages of 1.735 V to yield 500 mA cm-2 in alkaline water. Notably, they also exhibit exceptional electrocatalytic properties in alkaline seawater (1.833 V@500 mA cm-2 ). The experimental studies and theoretical calculations verify that Fe doping does reduce the energy barrier from OH* to O* intermediates during OER process after catalyst reconstruction, and the non-metallic N site from MoN exhibits the lowest theoretical overpotential. The splendid catalytic performance is attributed to the optimized local electron configuration and porous structure. This discovery provides a new design method toward low-cost and excellent catalysts for water/seawater splitting to produce hydrogen.

Investigating the levels, spatial distribution, and trophic transfer patterns of short-chain chlorinated paraffins in the Southern Bohai Sea, China.

The marine environment of the southern Bohai Sea is severely polluted by short-chain chlorinated paraffins (SCCPs). To improve understanding of how SCCPs occur and of how they migrate, are transformed, and transferred in this area, we collected seawater, sediment, and organism samples, and determined the SCCP contents using a new approach based on high-resolution mass spectrometry. The ΣSCCP concentrations in the seawater, sediment, and organism samples ranged from 57.5 to 1150.4 ng/L, 167.7-1105.9 ng/g (dry weight), and 11.4-583.0 ng/g (wet weight), respectively. Simulation of the spatial distribution of SCCPs using Kriging interpolation showed that SCCPs were markedly influenced by land-based pollution. Substantial quantities of SCCPs were transported to the marine environment via surface runoff from rivers that passed through areas of major SCCP production. Once discharged from such rivers into the Bohai Sea, these SCCPs were further dispersed under the influence of ocean currents. Furthermore, the logarithmic bioaccumulation factor that varied from 2.12 to 3.20 and the trophic magnification factor that reached 5.60 (r2 = 0.750, p < 0.01) suggest that organisms have the ability to accumulate and biomagnify SCCPs through the food chain, which could potentially present risks to both marine ecosystems and human health.

Multi-material 3D printed eutectogel microneedle patches integrated with fast customization and tunable drug delivery.

Microneedle patches are emerging multifunctional platforms for transdermal diagnostics and drug delivery. However, it still remains challenging to develop smart microneedles integrated with customization, sensing, detection and drug delivery by 3D printing strategy. Here, we present an innovative but facile strategy to rationally design and fabricate multifunctional eutectogel microneedle (EMN) patches via multi-material 3D printing. Polymerizable deep eutectic solvents (PDES) were selected as printing inks for rapid one-step fabrication of 3D printing functional EMN patches due to fast photopolymerization rate and ultrahigh drug solubility. Moreover, stretchable EMN patches incorporating rigid needles and flexible backing layers were easily realized by changing PDES compositions of multi-material 3D printing. Meanwhile, we developed multifunctional smart multi-material EMN patches capable of performing wireless monitoring of body movements, painless colorimetric glucose detection, and controlled transdermal drug delivery. Thus, such multi-material EMN system could provide an effective platform for the painless diagnosis, detection, and therapy of a variety of diseases.

Transparent, Mechanically Robust, Adhesive, Temperature-Tolerant, and 3D Printable Nanocomposite Ionogels for Flexible Sensors.

Ionogels are emerging as soft materials for flexible strain sensors. However, the integration of multiple functionalities into a single ionogel for diverse applications in complex scenarios remains a challenge. In this study, we present a multifunctional nanocomposite ionogel that combines high strength, transparency, stretchability, temperature tolerance, adhesiveness, and 3D printing capabilities. The ionogels are fabricated through a one-step photopolymerization process involving acrylic acid and 2-acrylamide-2-methylpropanesulfonic acid in an ionic liquid, with Al(OH)3 nanoparticles serving as cross-linkers. The resulting ionogels exhibit robust noncovalent interactions, including ionic coordination, hydrogen bonding, and ionic dipole interactions, providing exceptional mechanical strength, conductivity, and wide temperature tolerance while ensuring strong adhesion to various substrates. Wearable strain sensors based on these ionogels can accurately detect and differentiate a range of movements, from large body motions such as bending limbs to subtle distinctions such as writing different letters. Additionally, the pregel solution can serve as printing ink for the rapid and efficient mass production of 3D printed high-precision microcircuits. Impressively, the nanocomposite ionogels exhibit a high latent heat value of 240 J g-1 at a melting temperature of -65 °C, suggesting significant potential for cold energy storage in ultralow-temperature cold-chain transportation systems. Thus, these outstanding features of the ionogels offer a promising strategy for advancing wearable electronics and cold energy storage systems.

Sources, bioaccumulation, and toxicity mechanisms of cadmium in Chlamys farreri.

The Potentially toxic elements (PTEs) cadmium (Cd) is one of the most serious stressors polluting the marine environment. Marine bivalves have specific high enrichment capacity for Cd. Previous studies have investigated the tissue distribution changes and toxic effects of Cd in bivalves, but the sources of Cd enrichment, migration regulation during growth, and toxicity mechanisms in bivalves have not been fully explained. Here, we used stable-isotope labeling to investigate the contributions of Cd from different sources to scallop tissues. We sampled the entire growth cycle of Chlamys farreri, which is widely cultured in northern China, from juveniles to adult scallops. We found tissue variability in the bioconcentration-metabolism pattern of Cd in different bound states, with Cd in the aqueous accounting for a significant contribution. The accumulation pattern of Cd in all tissues during growth was more significant in the viscera and gills. Additionally, we combined a multi-omics approach to reveal a network of oxidative stress-induced toxicity mechanisms of Cd in scallops, identifying differentially expressed genes and proteins involved in metal ion binding, oxidative stress, energy metabolism, and apoptosis. Our findings have important implications for both ecotoxicology and aquaculture. They also provide new insights into marine environmental assessment and mariculture development.

Rice HEAT SHOCK PROTEIN60-3B maintains male fertility under high temperature by starch granule biogenesis.

Heat stress has a deleterious effect on male fertility in rice (Oryza sativa), but mechanisms to protect against heat stress in rice male gametophytes are poorly understood. Here, we have isolated and characterized a heat-sensitive male-sterile rice mutant, heat shock protein60-3b (oshsp60-3b), that shows normal fertility at optimal temperatures but decreasing fertility as temperatures increase. High temperatures interfered with pollen starch granule formation and reactive oxygen species (ROS) scavenging in oshsp60-3b anthers, leading to cell death and pollen abortion. In line with the mutant phenotypes, OsHSP60-3B was rapidly upregulated in response to heat shock and its protein products were localized to the plastid. Critically, overexpression of OsHSP60-3B enhanced the heat tolerance of pollen in transgenic plants. We demonstrated that OsHSP60-3B interacted with FLOURY ENDOSPERM6(FLO6) in plastids, a key component involved in the starch granule formation in the rice pollen. Western blot results showed that FLO6 level was substantially decreased in oshsp60-3b anthers at high temperature, indicating that OsHSP60-3B is required to stabilize FLO6 when temperatures exceed optimal conditions. We suggest that in response to high temperature, OsHSP60-3B interacts with FLO6 to regulate starch granule biogenesis in rice pollen and attenuates ROS levels in anthers to ensure normal male gametophyte development in rice.

Analyzing toxicological effects of AsIII and AsV to Chlamys farreri by integrating transcriptomic and metabolomic approaches.

Inorganic arsenic (iAs) is a widespread contaminant in marine environments, which is present in two different oxidation states (arsenate (AsV) and arsenite (AsIII)) that have complex toxic effects on marine organisms. The scallop Chlamys farreri (C. farreri) accumulates high levels of As and is a suitable bioindicator of As. In this report, we integrated transcriptomics and metabolomics to investigate genetic and metabolite changes and functional physiological disturbances in C. farreri exposured to inorganic arsenic. Physiological indicators antioxidant factors and cell apoptosis analysis macroscopically corroborated the toxic effects of inorganic arsenic revealed by omics results. Toxic effects of inorganic arsenic on C. farreri were signaling-mediated, causing interference with a variety of cell growth and small molecule metabolism. The results provide evidence that inorganic arsenic disrupts the physiological functions of bivalves, highlighting the correlations between different metabolic pathways and providing new insights into the toxic effects of environmental pollutants on marine organisms.

Dual selective sensor for exosomes in serum using magnetic imprinted polymer isolation sandwiched with aptamer/graphene oxide based FRET fluorescent ignition.

The selective and sensitive detection of cancerous exosomes in serum is critical for early disease diagnosis and improved prognosis. Previous exosome-related research has been limited by a lack of well-understanding in exosomes as well as the challenging background interference of body fluid. Molecularly imprinted polymers (MIPs) and nucleic acid aptamers can be regarded as the two alternatives to antibodies. When using imprinted polymer technology, comprehensive and precise information about the target constituents is not required. In this study, a novel kind of dual selective fluorescent nanosensor for the poorly characterized exosomes was constructed by integrating magnetic MIP selective exosome capture sandwiched with an aptamer/graphene oxide fluorescence resonance energy transfer system (FRET) based selective 'turn-on' exosome labeling heterogeneously. The overall strategy performance was successively evaluated using lysozyme and exosomes as targets. Good linearity and high sensitivity achieved were demonstrated. The LOD of exosomal detection in serum was 2.43 × 106 particles/mL, lower than other immunology based detection methods. The discrimination between serum from breast cancer patients and healthy people was also primarily studied. In conclusion, the developed sensor with outstanding selectivity, high detection sensitivity, simplicity, low cost, and wide applicability for known or unknown targets present significant potential in challenging clinical diagnosis.

Metabolomics comparison of metabolites and functional pathways in the gills of Chlamys farreri under cadmium exposure.

The biological processes of Chlamys farreri (C. farreri), an economically important shellfish, are affected when exposed to Cd2+. In this study, changes to biological processes and metabolite levels in C. farreri were examined when exposed to Cd2+. Ultra-performance liquid chromatography-tandem TOF mass spectrometry (UPLC-TOF/MS)-based untargeted metabolomics was used to examine changes in the metabolism of C. farreri gill tissue exposed to 0.050 mg/L Cd2+ for 96 h in a natural environment. Sixty-eight metabolites with significant differences were screened by multivariate statistical analysis. Eleven enriched functional pathways displayed significant changes in inactivity. Differential metabolites, mainly C00157 and C00350, have a significant impact on functional pathways and can be used as potential major biomarkers. Lipid phosphorylation, disruption of signal transduction, and autophagy activation were observed to change in C. farreri when exposed to Cd. The metabolome information supplements research on C. farreri exposure to heavy metals and provides a platform for further multi-omics analysis.

Tough Adhesion of Freezing- and Drying-Tolerant Transparent Nanocomposite Organohydrogels.

Tough hydrogels with strong wet adhesion have drawn extensive attention for various applications. However, it is still challenging to achieve both excellent wet adhesion and freezing- and drying-tolerance in hydrogels. In this study, we present tough transparent nanocomposite organohydrogels based on the glycerol-water binary solvent system in the presence of Al(OH)3 nanoparticles as a cross-linker. The resultant organohydrogels exhibited excellent tensile strength (∼0.9 MPa), high transparency (97%), superior anti-drying and anti-freezing properties, and good ionic conductivity. In particular, polyacrylic acid (PAA) was chosen as the bridging polymer to endow the organohydrogels with strong wet adhesion. The interfacial adhesion energy exceeded 2200 J m-2, which was ascribed to the synergy of ionic coordination and hydrogen bonds between the nanoparticles and carboxyl groups in PAA chains. Interestingly, based on the strong wet adhesion, the transparent organohydrogels can be assembled into hydraulically driven soft variable-focus lenses with long-term ambient stability. This work will provide a new insight into controlled wet adhesion ̵of hydrogel and have great potential for hydrogel-based functional devices with long-term ambient stability.

Grass-Specific EPAD1 Is Essential for Pollen Exine Patterning in Rice.

The highly variable and species-specific pollen surface patterns are formed by sporopollenin accumulation. The template for sporopollenin deposition and polymerization is the primexine that appears on the tetrad surface, but the mechanism(s) by which primexine guides exine patterning remain elusive. Here, we report that the Poaceae-specific EXINE PATTERN DESIGNER 1 (EPAD1), which encodes a nonspecific lipid transfer protein, is required for primexine integrity and pollen exine patterning in rice (Oryza sativa). Disruption of EPAD1 leads to abnormal exine pattern and complete male sterility, although sporopollenin biosynthesis is unaffected. EPAD1 is specifically expressed in male meiocytes, indicating that reproductive cells exert genetic control over exine patterning. EPAD1 possesses an N-terminal signal peptide and three redundant glycosylphosphatidylinositol (GPI)-anchor sites at its C terminus, segments required for its function and localization to the microspore plasma membrane. In vitro assays indicate that EPAD1 can bind phospholipids. We propose that plasma membrane lipids bound by EPAD1 may be involved in recruiting and arranging regulatory proteins in the primexine to drive correct exine deposition. Our results demonstrate that EPAD1 is a meiocyte-derived determinant that controls primexine patterning in rice, and its orthologs may play a conserved role in the formation of grass-specific exine pattern elements.

Clinicopathological features and prognostic analysis of 77 patients with multiple primary cancers.

PURPOSE: The purpose of this study was to analyze the characteristics, diagnosis and treatment principles and prognosis of multiple primary cancers (MPC). METHODS: A total of 77 patients with MPC admitted in the Central Hospital of Changsha from December 2013 to December 2018 were enrolled in this retrospective analysis. The survival of these 77 patients with complete follow-up data was calculated. RESULTS: There were 77 patients with multiple primary cancers, including 70 patients with double primary cancers, 6 patients with three primary cancers, and 1 patient with four primary cancers. Among the 77 MPC patients, there were 4 synchronous carcinomas (SC), 58 metachronous carcinomas (MC), and 15 unknown cases. The 3, 5, and 10-year overall survival rates of 77 patients with follow-up data were 86.5%, 18.2%, and 12.9%, respectively. The median survival time of 4 SC and 58 MC patients was 12 months and 108 months, respectively. The median survival time was 48.5 months in 23 patients with an interval of less than 5 years, and 108 months in 29 patients with first and second primary cancers whose interval was more than 5 years. The median survival time of 26 patients with second primary lung cancer was 84 months, and that of 23 patients with second primary non-lung cancer was 156 months. CONCLUSIONS: MPCs are more likely to occur in the colorectum, and the prognosis of patients with metachronous cancer is better than that of patients with synchronous cancer. The longer the interval between two cancers, the better the prognosis will be. The prognosis of the second primary non-lung cancer patients is better than that of the lung cancer patients.

Structural and functional insights into macrophage migration inhibitory factor from Oncomelania hupensis, the intermediate host of Schistosoma japonicum.

Oncomelania hupensis is the unique intermediate host of Schistosoma japonicum. As an irreplaceable prerequisite in the transmission and prevalence of schistosomiasis japonica, an in-depth study of this obligate host-parasite interaction can provide glimpse into the molecular events in the competition between schistosome infectivity and snail immune resistance. In previous studies, we identified a macrophage migration inhibitory factor (MIF) from O. hupensis (OhMIF), and showed that it was involved in the snail host immune response to the parasite S. japonicum. Here, we determined the crystal structure of OhMIF and revealed that there were distinct structural differences between the mammalian and O. hupensis MIFs. Noticeably, there was a projecting and structured C-terminus in OhMIF, which not only regulated the MIF's thermostability but was also critical in the activation of its tautomerase activity. Comparative studies between OhMIF and human MIF (hMIF) by analyzing the tautomerase activity, oxidoreductase activity, thermostability, interaction with the receptor CD74 and activation of the ERK signaling pathway demonstrated the functional differences between hMIF and OhMIF. Our data shed a species-specific light on structural, functional, and immunological characteristics of OhMIF and enrich the knowledge on the MIF family.

Complex multiphase organohydrogels with programmable mechanics toward adaptive soft-matter machines.

Many biological organisms can tune their mechanical properties to adapt to environments in multistable modes, but the current synthetic materials, with bistable states, have a limited ability to alter mechanical stiffness. Here, we constructed programmable organohydrogels with multistable mechanical states by an on-demand modular assembly of noneutectic phase transition components inside microrganogel inclusions. The resultant multiphase organohydrogel exhibits precisely controllable thermo-induced stepwise switching (i.e., triple, quadruple, and quintuple switching) mechanics and a self-healing property. The organohydrogel was introduced into the design of soft-matter machines, yielding a soft gripper with adaptive grasping through stiffness matching with various objects under pneumatic-thermal hybrid actuation. Meanwhile, a programmable adhesion of octopus-inspired robotic tentacles on a wide range of surface morphologies was realized. These results demonstrated the applicability of these organohydrogels in lifelike soft robotics in unconstructed and human body environments.

Large-area superelastic graphene aerogels based on a room-temperature reduction self-assembly strategy for sensing and particulate matter (PM2.5 and PM10) capture.

Graphene aerogels are emerging low density and superelasticity macroscopic porous materials with various applications. However, it still remains a challenge to develop a versatile strategy under ambient conditions for fabricating large-area, high-performance graphene aerogels, which is crucial for their practical applications. Here, we report a novel room-temperature reduction self-assembly (RTRS) strategy to fabricate large-area graphene aerogels under ambient conditions. The strategy is based on using unique hydrazine hydrates as reducing agents to generate stable microbubbles beneficial for the formation of macroporous graphene hydrogels. Interestingly, the resultant hydrogel followed by a simple pre-freeze treatment can be naturally dried into graphene aerogels without noticeable volume shrinkage or structure cracking. Benefiting from the mild conditions, a large-area graphene aerogel with a diameter of up to 27 cm was prepared as an example. The as-formed aerogels exhibit a stable honeycomb-like coarse-pores structure, a low density of 3.6 mg cm-3 and superelasticity (rapidly recoverable from 95% compression) which are suitable for pressure/strain sensors. Moreover, the aerogel exhibits superior particulate matter adsorption efficiency (PM2.5: 93.7%, PM10: 96.2%) and good recycling ability. Importantly, the preparation process is cost-effective and easily scalable without the need for any special drying techniques and heating processes, which provides an ideal platform for mass production of graphene aerogels toward practical applications.

Strong Wet Adhesion of Tough Transparent Nanocomposite Hydrogels for Fast Tunable Focus Lenses.

Tough hydrogel adhesives that can bond strongly to wet surfaces have shown great potential in various applications. However, it still remains a challenge to develop the adhered hydrogels integrated with strong wet adhesion, high transparency, exceptional mechanical properties, and fast self-recovery. Herein, tough nanocomposite hydrogels demonstrating high tensile strength, high transparency, and fast self-recovery are reported. The strong wet adhesion between two tough hydrogel films can be realized by introducing chemical bridging across the hydrogel-hydrogel interface, while the interfacial adhesion energy and shearing adhesion strength are up to 2216 J m-2 and 385 N m-1, respectively. The strong adhesion and superior toughness of our hydrogels enable their reassembly capability to produce stretchable sealed balloons that can endure high air pressure without leakage. Most interestingly, the combination of excellent sealability and high transparency also allows our hydrogel balloons to turn into hydraulically driven fast tunable focus convex lenses, which is first reported here for hydrogel lenses. The hydrogel adhesives may open up the door to develop soft sealed containers and intelligent optical devices.

Water-Evaporation-Powered Fast Actuators with Multimodal Motion Based on Robust Nacre-Mimetic Composite Film.

Water evaporation as a source of energy to trigger moisture-responsive soft materials is an emerging field in a variety of energy-harvesting devices, which has attracted widespread attention. Here, we design and fabricate bioinspired nacrelike composite film actuators consisting of graphene oxide and sodium alginate, which demonstrate an obvious shrinkage in volume when their state transfers from wet to dry and the contractile stress is up to 42.3 MPa. Based on these features, the film actuators can show rapid and continuous movements under the water gradient. The flipping frequency of the actuators can reach up to 76 rounds min-1, which is much faster than those in previous reports. The film can flap back and forth quickly on water vapor even after loading a cargo that is 9 times its own weight. Moreover, high mobility with multimodal motion including blooming, stretching, folding, and twisting can also be achieved by modulating the shapes of films. Thus, film actuators may hold great potential in many fields, such as microrobots, artificial muscles, and sensors on grounds of their rapid response speed and adjustable motion models.

Highly Stretchable Room-Temperature Self-Healing Conductors Based on Wrinkled Graphene Films for Flexible Electronics.

Flexible conductors are emerging soft materials for diverse electrical applications. However, it still remains a great challenge to fabricate high-performance soft conductors that are highly conductive, largely stretchable, and rapid room-temperature self-healable. Here, we design and fabricate flexible conductive bilayer composite films composed of healable elastomeric substrates and wrinkled graphenes. The elastomeric substrates, obtained by a facile bulk copolymerization of N-isopropylacrylamide and 2-methoxyethyl acrylate, show fast room-temperature self-healing efficiency of up to 96%, imparted by the reversible hydrogen bonds. Importantly, the substrates also display strong interfacial adhesion crucial to the formation of stable bilayer composite films based on a prestrain route. The synergy between self-healing of the substrates and wrinkled structures of graphene is endowed to the composite films for mechanical and electrical healing. By adjusting the prestrain ratio of the substrates, the composite films could display the tunable stretchability, conductivity, and self-healing. The optimal bilayer composite film exhibits a high conductivity of 126 S cm-1, a large stretchability of 300%, and rapid room-temperature self-healing. Moreover, it is demonstrated that the composite films are strain-sensitive and can be used as strain sensors to monitor stretching deformation and human motion. These prominent demonstrations suggest a great potential of the bilayer composite films in next-generation wearable electronics.