Rapid Self-healing Ability Research Articles

Multifunctional chondroitin sulfate based hydrogels for promoting infected diabetic wounds healing by chemo-photothermal antibacterial and cytokine modulation

Diabetic foot (DF) is difficult to heal due to the formation of drug-resistant bacterial biofilms and dysregulation of the wound microenvironment. To solve this problem, multifunctional hydrogels were prepared by in situ or spraying with 3-aminophenylboronic acid modified oxidized chondroitin sulfate (APBA-g-OCS), polyvinyl alcohol (PVA) and black phosphorus/bismuth oxide/ε-polylysine (BP/Bi2O3/ε-PL) as precursors for promoting infected diabetic wounds healing. The hydrogels display multiple stimulus responsiveness, strong adhesion and rapid self-healing ability owing to the dynamic borate ester bonds, hydrogen bonds and π-π conjugation cross-link points, remain synergistic chemo-photothermal antibacterial effect and anti-biofilm formation ability due to the doping of BP/ Bi2O3/ε-PL into the hydrogel by dynamic imine bonds crosslinking and possess anti-oxidation and inflammatory chemokine adsorption ability attributing to the presence of APBA-g-OCS. Most importantly, as a result of the above functions, the hydrogels can not only respond to the wound microenvironment to conduct combined PTT and chemotherapy for efficient anti-inflammation, but also improve the wound microenvironment by scavenging ROS and regulating the expression of cytokines, thus further accelerating collagen deposition, promoting granulation tissue formation and angiogenesis, finally promoting the healing of infected wounds in diabetic rats.

Totally dynamically cross-linked dual-network conductive hydrogel with superb and rapid self-healing ability for motion detection sensors

To overcome the status quo of fragile network and single function in the single-network hydrogel, this work designed and fabricated a dual-network O-CMCS (O-carboxymethyl chitosan)/PVA (polyvinyl alcohol) PBOC conductive hydrogel based on two kinds of totally dynamic reversible cross-linking networks. The PBOC conductive hydrogel combined a flexible O-PT (oxidized pectin)/O-CMCS network with a rigid PVA-borax network, and CNTs (carbon nanotubes) were introduced to improve its toughness and conductivity. Its structural characteristics were investigated through Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffractometer (XRD), nuclear magnetic resonance (NMR) and other techniques. Its superb and rapid self-healing property was confirmed through dynamic rheological tests, and its electrical property was studied through an electrochemical workstation. The co-existence of the dual networks endowed the PBOC conductive hydrogel with excellent stretchable property (821% of the maximum elongation at break), and it could quickly self-heal within 60 s after being cut due to the intense interaction of totally reversible multiple dynamic bonding. Notably, the PBOC conductive hydrogel strain sensor exhibited high strain sensitivity with GF (gauge factor) of 8.44 at 800% strain and could accurately detect all kinds of human motions (e.g. finger bending, wrist bending and elbow bending, etc.), confirming its tremendous application potential in the field of wearable sensor devices.

Self-Healing of Biocompatible Superhydrophobic Coatings: The Interplay of the Size and Loading of Particles.

The broad application potential of superhydrophobic coatings is limited by the usage of environment-threatening materials and poor durability. The nature-inspired design and fabrication of self-healing coatings is a promising approach for addressing these issues. In this study, we report a fluorine-free and biocompatible superhydrophobic coating that can be thermally healed after abrasion. The coating is composed of silica nanoparticles and carnauba wax, and the self-healing is based on surface enrichment of wax in analogy to the wax secretion in plant leaves. The coating not only exhibits fast self-healing, just in 1 min under moderate heating, but also displays increased water repellency and thermal stability after healing. The rapid self-healing ability of the coating is attributed to the relatively low melting point of carnauba wax and its migration to the surface of the hydrophilic silica nanoparticles. The dependence of self-healing on the size and loading of particles provides insights into the process. Furthermore, the coating exhibits high levels of biocompatibility where the viability of fibroblast L929 cells was ∼90%. The presented approach and insights provide valuable guidelines in the design and fabrication of self-healing superhydrophobic coatings.

Intrinsically Nonswellable Multifunctional Hydrogel with Dynamic Nanoconfinement Networks for Robust Tissue-Adaptable Bioelectronics.

Developing bioelectronics that retains their long-term functionalities in the human body during daily activities is a current critical issue. To accomplish this, robust tissue adaptability and biointerfacing of bioelectronics should be achieved. Hydrogels have emerged as promising materials for bioelectronics that can softly adapt to and interface with tissues. However, hydrogels lack toughness, requisite electrical properties, and fabrication methodologies. Additionally, the water-swellable property of hydrogels weakens their mechanical properties. In this work, an intrinsically nonswellable multifunctional hydrogel exhibiting tissue-like moduli ranging from 10 to 100kPa, toughness (400-873 J m-3 ), stretchability (≈1000% strain), and rapid self-healing ability (within 5min), is developed. The incorporation of carboxyl- and hydroxyl-functionalized carbon nanotubes (fCNTs) ensures high conductivity of the hydrogel (≈40Sm-1 ), which can be maintained and recovered even after stretching or rupture. After a simple chemical modification, the hydrogel shows tissue-adhesive properties (≈50kPa) against the target tissues. Moreover, the hydrogel can be 3D printed with a high resolution (≈100µm) through heat treatment owing to its shear-thinning capacity, endowing it with fabrication versatility. The hydrogel is successfully applied to underwater electromyography (EMG) detection and ex vivo bladder expansion monitoring, demonstrating its potential for practical bioelectronics.

Glycopolymer-based multifunctional antibacterial hydrogel dressings for accelerating cutaneous wound healing.

Antimicrobial hydrogel dressings have received extensive attention for their wide and promising applications in preventing infections associated with wound healing. However, the development of versatile antibacterial hydrogels inevitably leads to complex structures, which restricts their applications. In this work, a multifunctional antibacterial hydrogel based on a reversible diolborate bond crosslinked network was prepared via the interactions between the zwitterionic glycopolymer poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(N,N-dimethylacrylamide)-co-(2-lactobionamidoethyl methacrylamide)] (PMDL) and borax in conjunction with a simple mixing of Ag NPs within 10 s. The obtained PMDL-12%/borax/Ag NP hydrogel displays a rapid self-healing ability and excellent injectability, as well as good adhesiveness to biological tissues and surfaces of various materials. Moreover, the hydrogels exhibit efficient antibacterial activities against Escherichia coli and Staphylococcus aureus, which could prevent bacterial infections in wound care. The multifunctional hydrogel also shows good cytocompatibility and hemocompatibility. Importantly, in vivo wound healing evaluation of a mouse full-thickness skin defect model confirms that the hydrogel effectively accelerates cutaneous regeneration and wound healing by regulating inflammation and promoting collagen deposition. This multifunctional wound dressing hydrogel prepared using a facile strategy has promising application in biomedical areas.

High-performance environmental adaptive microsupercapacitors from multifunctional hydrogel via modulating ionic hydration and hydrogen bonds

The advance of microelectronic systems requires their energy power microsupercapacitors (MSCs) possessing environmental adaptability beyond the high energy density. The electrolyte in MSCs plays a crucial role in satisfying the above requirements. In this work, we experimentally demonstrate the hydrogel electrolyte with multifunctions, including ultralow phase-transition temperature of -103.8 °C, 2.80 V electrochemical window, superior anti-dehydration and rapid self-healing ability, via modulating its ionic hydration and hydrogen bonds. It is used to build graphene-based MSCs, which show promising energy density of 41.56 µWh cm−2, super-wide working temperature range from -60 to 100 °C, exciting self-regeneration ability after deep dehydration and self-healing ability under severe physical damage. The MSCs meet the requirement of advanced microelectronic systems. The strategy developed here paves a way towards high-performance MSCs in harsh environment.

Construction of a strong, fast self-healing adhesive for propellants based on the synergy of weak hydrogen bond array reorganization and disulfide exchange reactions

Internal damage of propellant, especially interfacial debonding, can easily cause major accident and consume a lot of costs. Although some literatures describe the application of self-healing adhesives in the field of propellant, the mechanical properties are usually poor, and the application of self-healing adhesives on debonded interfaces has never been studied. In this work, a high-strength polyurethane adhesive with tensile strength greater than 10 MPa and rapid self-healing ability (recovery at room temperature for 24 h) was constructed based on multiple weak hydrogen bond arrays and highly active disulfide bonds. Importantly, we ground breakingly tested the self-healing effect for interfacial debonding. Benefiting from the high-strength adhesion of a large number of hydrogen bond arrays, the peel strength of the adhesive at the propellant interface is 140% higher than that of traditional adhesives. At the same time, it can effectively heal the debonded interface, and the peel strength is still higher than that of traditional adhesives even undergo secondary healing. Our work has implications for solving the industry's thorny - propellant interface debonding.

Physically crosslinked PAA/Lys-BPEA hydrogel with rapid self-healing and long-term antibacterial activities

Diseases caused by bacterial infections continue to threaten human health around the world. Antimicrobial hydrogels with excellent properties have been developed in biomaterial and other fields in some cases, where overuse or inappropriate use of antibiotics has led to increased bacterial resistance. In this study, primary amines that are rich in lysine end groups were used to synthesize Lys-BPEA crosslinker. An antibacterial self-healing hydrogel (labeled as polyacrylic acid [PAA/]/Lys-BPEA) was prepared by introducing polyamine Lys-BPEA into PAA via ionic bonding and electrostatic interaction. The surface morphology and mechanical properties, especially the antibacterial and self-healing properties, of the created physically crosslinked PAA-lysine polyetheramide hydrogels were investigated. The PAA/Lys-BPEA hydrogel realized a comprehensive performance of long-term antibacterial activity without inducing drug resistance, low hemolysis activity and rapid self-healing ability. Therefore, the performance of the combination makes the PAA/Lys-BPEA hydrogel an ideal candidate for the design of smart self-healing devices and antibacterial surface coatings.

Thermoresponsive Self-Healing Zwitterionic Hydrogel as an In Situ Gelling Wound Dressing for Rapid Wound Healing.

It is highly desired yet challenging to fabricate biocompatible injectable self-healing hydrogels with anti-bacterial adhesion properties for complex wounds that can autonomously adapt to different shapes and depths and can promote angiogenesis and dermal collagen synthesis for rapid wound healing. Herein, an injectable zwitterionic hydrogel with excellent self-healing property, good cytocompatibility, and antibacterial adhesion was developed from a thermoresponsive ABA triblock copolymer poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)]-b-poly(ethylene glycol)-b-poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)] (PZOPZ). The prepared PZOPZ hydrogel exhibits a distinct thermal-induced sol-gel transition around physiological temperature and could be easily applied in a sol state and in situ gelled to adapt complex wounds of different shapes and depths for complete coverage. Meanwhile, the hydrogel possesses a rapid self-healing ability and can recover autonomously from damage to maintain structural and functional integrity. In addition, the CCK-8 and 2D/3D cell culture experiments revealed that the PZOPZ hydrogel dressing shows low cytotoxicity to L929 cells and can effectively prevent the adhesion of Staphylococcus aureus and Escherichia coli. In vivo investigations verified that the PZOPZ hydrogel could increase angiogenesis and dermal collagen synthesis and shorten the transition from the inflammatory to the proliferative stage, thereby providing more favorable conditions for faster wound healing. Overall, this work provides a promising strategy to develop injectable zwitterionic hydrogel dressings with multiple functions for clinic wound management.

Self-healing and elastic polymer gel via terpyridine-metal coordination

A supramolecular polymer is prepared by tristerpyridine ligand and metal ion Zinc coordination. When the supramolecular polymer is dissolved in acetonitrile, a metallo-gel can be obtained at a very low monomer concentration (< 1.0 wt%). Remarkably, this metallo-gel exhibits rapid self-healing ability and excellent elasticity with high recovery. • Coordination gelation was observed at very low monomer concentrations, indicating gel- A /Zn 2+ was a highly potential supergelator. • The supramolecular gel exhibited a great macroscopic self-healing ability. • A good elastic behavior was observed from gel- A /Zn 2+ . Self-healing and elasticity are assiduously pursued qualities for substrate materials which are applicable in many fields such as wearable electronic devices, touch screens, and soft robotics. Up to now, the most reported self-healing and elastic gel materials were constructed by supramolecular polymers with covalent backbones. Herein, a supramolecular gel- A /Zn 2+ was built based on supramolecular polymerization through terpyridine-Zn 2+ coordination. Importantly, this metallo-gel exhibits the self-healing ability. In addition, a freshly prepared metallo-gel ball with a diameter of 1.0 cm could rebound back with 89.6% recovery from free-drop which displayed excellent elasticity. Superb features of gel- A /Zn 2+ including self-healing ability, elasticity and hydrophilia provide prospects for high-performance adaptive materials.

Skin-friendly PVA/PDA/Tyr-PEAm composite hydrogel with long-term antibacterial and self-recovery ability for wearable strain/pressure sensor

Flexible and self-healing conductive hydrogel, as a typical electronic skin with the function of transmitting sensory signals, has attracted remarkable attentions in the biomaterials field. However, the practical application of electronic skin has been severely limited owing to the potential bacterial infection threats. Here, in order to improve the antibacterial properties of electronic skin, a star-shaped polyetheramide (Tyr-PEAm) derived from L-tyrosine was synthesized and cross-linked into the hydrogel network. A compliant and self-healing conductive hydrogel (defined as PVA/PDA/Tyr-PEAm) was assembled from polyvinyl alcohol (PVA), polydopamine (PDA) and Tyr-PEAm. The hydrogel achieved a comprehensive performance of long-term antibacterial activity (the inhibition zones remained unchanged over 7 days), low hemolysis activity (hemolysis rate of 0.042 %), good conductivity and rapid self-healing ability (healing within 1 s). Therefore, the hydrogel could be used not only as a detection device to check normal skin, but also as the wound skin detection in real time. Furthermore, the good conductivity and rapid self-healing ability contributed to the hydrogel to detect various macro and micro movements of the human body, as well as to recycle as a new sensor. The PVA/PDA/Tyr-PEAm hydrogel that integrated intelligent signals and resisted bacterial infections exhibited broad application prospects in biomedical materials.

Near-Infrared Responsive Smart Superhydrophobic Coating with Self-Healing and Robustness Enhanced by Disulfide-Bonded Polyurethane.

Synergistic self-healing materials and inorganic particles to create self-healing superhydrophobic surfaces for improving their robustness is a common technique, but the suitability between the two is rarely mentioned. In this work, we developed a multifunctional superhydrophobic coating with room-temperature stability, mechanical stability, self-healing, and NIR stimuli response, in which self-healing polyurethane (PU) serves as the interface reinforcement layer and poly(dopamine) (PDA)-coated flower-like ZnO composite particles serve as the hydrophobic layer. A series of temperature-dependent self-healing PU materials were designed and synthesized by regulating the ratio of hard and soft chain segments in PU, and the relationship between the healing temperature of PU and the hydrophobic stability of the composite coatings was investigated. Based on dynamic hydrogen and disulfide bonds, PUs displayed excellent self-healing performance. Thanks to the self-healing and interfacial strengthening effect of PU and the photothermal properties of PDA, the composite coating exhibits not only excellent mechanical stability but also rapid self-healing ability in response to NIR stimuli. Furthermore, the smart coating demonstrated superior self-cleaning and corrosion resistance. This work provides a reference for developing strong and stable water-repellent reversible superhydrophobic coatings with great potential and promising future.

Injectable and fast gelling hyaluronate hydrogels with rapid self-healing ability for spinal cord injury repair

Self-healing natural hydrogels still suffer from some issues such as unfit stiffness, poor healing efficiency, and lack of biocompatibility and hydrolytic stability, although they have been used to treat spinal cord injury (SCI). Herein, we develop the injectable, self-healing hyaluronate hydrogels based on multiple dynamic covalent bonds. The hydrogels exhibit fast gelation and excellent self-healing capability as well as injectability, favoring in situ formation for the hydrogels in target sites and maintaining their structural stability. Furthermore, the hydrogels are compatible with neural stem cells and various tissues and possess proper stiffness similar to nervous tissue. Interestingly, the hydrogel can induce neural differentiation of neural stem cells. In vivo experiment further illustrates that the hydrogels promote angiogenesis and remyelination as well as neuron regeneration, leading to the significant locomotor recovery of the SCI model rats. This injectable self-healing hyaluronic acid-based hydrogel is a potential candidate for nerve repair.

A ternary heterogeneous hydrogel with strength elements for resilient, self-healing, and recyclable epidermal electronics

Epidermal sensing devices, which mimic functionalities and mechanical properties of natural skin, offer great potential for real-time health monitoring via continuous checking of vital signs. However, most existing skin-mounted electronics use a flexible film with high elastic modulus, which hinders physical activity and causes interfacial delamination and skin irritation. The compliance of hydrogel-based devices can firmly conform to complex, curved surfaces without introducing excessive interfacial stresses. However, most hydrogels still suffer from the weakness of stable and reproducible sensing. In this work, we report a skin-friendly epidermal electronic made of a resilient, self-healing, and recyclable polyvinyl alcohol (PVA) hydrogel. The hydrogel is reinforced through a ternary heterogeneous network for good mechanical robustness while maintaining high stretchability and exceptional conformability. Simultaneously, the abundant dynamic hydrogen bonds give the hydrogel rapid self-healing ability. The assembled hydrogel epidermal electronic is able to stably monitor multiple physiological signals as well as sense the strain level of the skin motion and joint bending. The unique, versatile, environmental and biological friendly epidermal electronics will have broad applications in health care, human-machine interface, augmented reality, and so on.

Polysaccharide/Ti3C2Tx MXene adhesive hydrogels with self-healing ability for multifunctional and sensitive sensors

Integrating functionalities such as adhesiveness, self-healing, and conductivity on a polysaccharide-based hydrogel is highly desirable for ever-expanding practical applications, but there is always a challenge. Herein, an elaborately designed nanocomposite hydrogel is fabricated by the addition of highly conductive Ti3C2Tx MXene nanosheets into chondroitin sulfate (CS)/N, N-dimethylamino ethyl acrylate (DMAEA-Q) hydrogel network. Owing to the introduction of sulfonated Ti3C2Tx MXene nanosheets, the as-prepared nanocomposite hydrogels exhibit excellent stretchability (> 5000% strain), rapid self-healing ability (< 60 s), and high adhesiveness (≈ 100 kPa). The proposed hydrogel demonstrates an outstanding electrical conductivity up to 5.33 S/m, allowing real-time monitoring of the bending and stretching movements and full recovery. Furthermore, the SMC hydrogels exhibit fast and stable photothermal conversion performance due to the inherent photothermal behavior. Notably, multifunctional SMC hydrogels present real-time and reversible humidity sensing upon H2O-induced swelling/contraction of nanochannels between the Ti3C2Tx MXene interlayers, enabling respiration monitoring applications.

Stable silicon anodes realized by multifunctional dynamic cross-linking structure with self-healing chemistry and enhanced ionic conductivity for lithium-ion batteries

Silicon anodes have attracted enormous attention with the merits of outstanding theoretical capacity for high-energy-density lithium-ion batteries. However, the drastic volume variation will destroy the structural integrity of the electrode system during the alloying/dealloying process. Herein, based on the supramolecular self-assembly, a multifunctional dynamic cross-linking strategy with self-healing chemistry and enhanced ionic conductivity for silicon electrode network structure is rationally designed by amino-functionalized silicon (Si-NH2) and dopamine-modified poly(acrylic acid) (PAA-DA). Dynamic reversible hydrogen bonds and ionic bonds are formed by random cross-linking of the primitives carried by the material, which endow the electrode with rapid self-healing ability and strong adhesion, and provide a continuous internal pathway for the electrode system. Moreover, the presence of polar groups can beneficially heighten the transport kinetics of lithium ions. The prepared Si-NH2@PAA-DA electrode displays excellent high-rate capability with a reversible capacity of 2671.6 mAh g−1 at 1 C (1 C = 4000 mA g−1) and superior cycle stability (2160.1 mAh g−1 after 100 cycles at 400 mA g−1). Therefore, this design idea with dynamic reversible and multi-crosslink network structure provides in-depth insights for the advancement of the next-generation high-energy-density batteries.

Bioinspired dual dynamic network hydrogels promote cartilage regeneration through regulating BMSC chondrogenic differentiation

How to improve the therapeutic efficacy of cell delivery during mechanical injection has been a great challenge for tissue engineering. Here, we present a facile strategy based on dynamic chemistry to prepare injectable hydrogels for efficient stem cell delivery using hyaluronic acid (HA) and poly(γ-glutamic acid) (γ-PGA). The combination of the guest–host (GH) complexation and dynamic hydrazone bonds enable the HA/γ-PGA hydrogels with physical and chemical dual dynamic network and endow hydrogels a stable structure, rapid self-healing ability, and injectability. The mechanical properties, self-healing ability, and adaptability can be programmed by changing the ratio of GH network to hydrazine bond cross-linked network. Benefitting from the dynamic cross-linking networks, mild preparation process, and cytocompatibility of HA/γ-PGA hydrogels, bone marrow mesenchymal stem cells (BMSCs) show high cell viability in this system following mechanical injection. Moreover, HA/γ-PGA hydrogels can promote BMSC proliferation and upregulate the expression of cartilage-critical genes. Notably, in a rabbit auricular cartilage defect model, BMSC-laden HA/γ-PGA hydrogels can effectively promote cartilage regeneration. Together, we propose a general strategy to develop injectable self-healing HA/γ-PGA hydrogels for effective stem cell delivery in cartilage tissue engineering.

A tough hydrogel with fast self-healing and adhesive performance for wearable sensors

The purpose of this work is to address the two existing challenges. One is to achieve the balance of mechanical properties, adhesion, and self-healing ability in hydrogel used in wearable devices. The other is to use mature products as raw materials and simplify the preparation process of adhesive hydrogels, so as to make it possible for large-scale industrial production. A novel PAA/Fe/PVP hydrogel has been prepared by a simple one-step radical polymerization to meet the above requirements. As the main component of adhesives in daily life, PVP is used to improve the adhesion of the hydrogel. The adhesion as high as 64 kPa is achieved in the hydrogel. The adhesion can also withstand multiple uses due to the good mechanical properties of the hydrogel. Furthermore, the hydrogel displays outstanding self-healing ability in terms of both mechanical properties and conductivity. Because of the good mechanical properties, robust adhesion and rapid self-healing ability, the hydrogel-based sensors have demonstrated stability, accuracy and reliability in real-time monitoring of subtle facial micro-expressions and large human activities. In addition, the method uses mature products as raw materials, and the preparation process is simple, so it has the potential for large-area and low-cost production.

Main‐Side Chain Hydrogen Bonding‐Based Self‐Healable Polyurethane with Highly Stretchable, Excellent Mechanical Properties for Self‐Healing Acid–Base Resistant Coating

Developing an autonomous self-healing polyurethane (PU) elastomer with excellent mechanical properties and high ductility has attracted increasing attention. Nowadays, the synthesis of elastomers with excellent mechanical properties and rapid self-healing at room temperature faces a huge challenge. Herein, This work reports a new supramolecular PU with excellent mechanical properties and rapid self-healing at room temperature through the introduction of T-type chain extender into the supramolecular polymer chain. The introduction of T-chain extender can be used to enhance the mechanical strength of PU, and the multiple hydrogen bonds on the side-chain provide theoretical support for the rapid self-healing ability of PU. Maximum stress of the synthesized PU can reach 3.4 ± 0.15 Mpa, and maximum elongation at break can reach 3200% ± 160%. Due to flexibility and re-constructability of side-chain hydrogen bonds, PU stress repair efficiency can reach 96.7%, and can be self-healing scratches rapidly and effectively at room temperature. The mechanical properties and self-healing properties of PU can be adjusted by the content of T-type chain extender. The PU is applied to the metal surface coating, which has excellent acid-base resistance, bond strength up to 2.9 ± 0.1 Mpa, and the ability to eliminate local damage on the coating surface quickly at room temperature.

Rapid self-healing and self-adhesive chitosan-based hydrogels by host-guest interaction and dynamic covalent bond as flexible sensor

A sensor used to monitor tissue deformation requires good flexibility, stretchability, self-adhesion, cyto-compatibility, and antibacterial property. Here, we prepared hydrogel sensor based on O-carboxymethyl chitosan (O-CMCS) and poly(vinyl alcohol) (PVA) for monitoring human and organ motions. Based on the host-guest complexing of poly(β-cyclodextrin) with diamantane, a cross-linker containing multiple aldehyde groups was prepared for cross-linking with O-CMCS through Schiff base linkages. Borax was used as the second cross-linker to cross-link PVA through dynamic borate ester bonds. Carbon nanotubes (CNTs) were added into the hydrogels to improve their electrical conductivity and mechanical properties. The obtained hydrogel exhibited rapid self-healing ability with healing efficiency as high as 97%–103% (in 15 s), good adhesion to human skin and wet organ, good antibacterial property, cyto-compatibility, and stretchability. Furthermore, the hydrogel sensor can monitor the respiratory movement of porcine lungs and the beating of rat hearts.