We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,wh...We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,while the ionic cross-linked hydrogel of terbium ions and sodium alginate serves as the second network.The double-network structure,the introduction of nanoparticles and the reversible ionic crosslinked interactions confer high mechanical properties to the hydrogel.Terbium ions are not only used as the ionic cross-linked points,but also used as green emitters to endow hydrogels with fluorescent properties.On the basis of the “antenna effect” of terbium ions and the ion exchange interaction,the fluorescence of the hydrogels can make selective responses to various ions(such as organic acid radical ions,transition metal ions) in aqueous solutions,which enables a convenient strategy for visual detection toward ions.Consequently,the fluorescent double network hydrogel fabricated in this study is promising for use in the field of visual sensor detection.展开更多
Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-...Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.展开更多
Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composite...Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.展开更多
A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled...A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.展开更多
The development of bioinspired gradient hydrogels with self-sensing actuated capabilities for remote interaction with soft-hard robots remains a challenging endeavor. Here, we propose a novel multifunctional self-sens...The development of bioinspired gradient hydrogels with self-sensing actuated capabilities for remote interaction with soft-hard robots remains a challenging endeavor. Here, we propose a novel multifunctional self-sensing actuated gradient hydrogel that combines ultrafast actuation and high sensitivity for remote interaction with robotic hand. The gradient network structure, achieved through a wettability difference method involving the rapid precipitation of MoO_(2) nanosheets, introduces hydrophilic disparities between two sides within hydrogel. This distinctive approach bestows the hydrogel with ultrafast thermo-responsive actuation(21° s^(-1)) and enhanced photothermal efficiency(increase by 3.7 ℃ s^(-1) under 808 nm near-infrared). Moreover, the local cross-linking of sodium alginate with Ca^(2+) endows the hydrogel with programmable deformability and information display capabilities. Additionally, the hydrogel exhibits high sensitivity(gauge factor 3.94 within a wide strain range of 600%), fast response times(140 ms) and good cycling stability. Leveraging these exceptional properties, we incorporate the hydrogel into various soft actuators, including soft gripper, artificial iris, and bioinspired jellyfish, as well as wearable electronics capable of precise human motion and physiological signal detection. Furthermore, through the synergistic combination of remarkable actuation and sensitivity, we realize a self-sensing touch bioinspired tongue. Notably, by employing quantitative analysis of actuation-sensing, we realize remote interaction between soft-hard robot via the Internet of Things. The multifunctional self-sensing actuated gradient hydrogel presented in this study provides a new insight for advanced somatosensory materials, self-feedback intelligent soft robots and human–machine interactions.展开更多
High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use i...High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft electronics.To resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)system.The well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1) at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and adhesion.Additionally,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic devices.The highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output performance.In particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1 mA cm^(-2))and excellent environmental adaptability.This study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.展开更多
The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,sp...The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.展开更多
Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct stacking.Hydrogel electrolytes are appea...Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct stacking.Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness,high conductivity and intrinsic flexibility.However,the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors.Here,we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance.The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode.Meanwhile,the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures.More significantly,the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance,delivering high-energy density of 39 Wh kg^(-1)at-60°C with capacity retention of 98.7%over 10,000 cycles.With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte,the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at-60°C.This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.展开更多
The anti-freezing strategy of hydrogels and their self-healing structure are often contradictory,it is vital to break through the molecular structure to design and construct hydrogels with intrinsic anti-freezing/self...The anti-freezing strategy of hydrogels and their self-healing structure are often contradictory,it is vital to break through the molecular structure to design and construct hydrogels with intrinsic anti-freezing/self-healing for meeting the rapid development of flexible and wearable devices in diverse service conditions.Herein,we design a new hydrogel electrolyte(AF/SH-Hydrogel)with intrinsic anti-freezing/self-healing capabilities by introducing ethylene glycol molecules,dynamic chemical bonding(disulfide bond),and supramolecular interaction(multi-hydrogen bond)into the polyacrylamide molecular chain.Thanks to the exceptional freeze resistance(84%capacity retention at-20℃)and intrinsic self-healing capabilities(95%capacity retention after 5 cutting/self-healing cycles),the obtained AF/SH-Hydrogel makes the zinc||manganese dioxide cell an economically feasible battery for the state-of-the-art applications.The Zn||AF/SH-Hydrogel||MnO_(2)device offers a near-theoretical specific capacity of 285 m A h g^(-1)at 0.1 A g^(-1)(Coulombic efficiency≈100%),as well as good self-healing capability and mechanical flexibility in an ice bath.This work provides insight that can be utilized to develop multifunctional hydrogel electrolytes for application in next generation of self-healable and freeze-resistance smart aqueous energy storage devices.展开更多
Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic ker...Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.展开更多
Highly entangled hydrogels exhibit excellent mechanical properties,including high toughness,high stretchability,and low hysteresis.By considering the evolution of randomly distributed entanglements within the polymer ...Highly entangled hydrogels exhibit excellent mechanical properties,including high toughness,high stretchability,and low hysteresis.By considering the evolution of randomly distributed entanglements within the polymer network upon mechanical stretches,we develop a constitutive theory to describe the large stretch behaviors of these hydrogels.In the theory,we utilize a representative volume element(RVE)in the shape of a cube,within which there exists an averaged chain segment along each edge and a mobile entanglement at each corner.By employing an explicit method,we decouple the elasticity of the hydrogels from the sliding motion of their entanglements,and derive the stress-stretch relations for these hydrogels.The present theoretical analysis is in agreement with experiment,and highlights the significant influence of the entanglement distribution within the hydrogels on their elasticity.We also implement the present developed constitutive theory into a commercial finite element software,and the subsequent simulations demonstrate that the exact distribution of entanglements strongly affects the mechanical behaviors of the structures of these hydrogels.Overall,the present theory provides valuable insights into the deformation mechanism of highly entangled hydrogels,and can aid in the design of these hydrogels with enhanced performance.展开更多
Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic ...Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic scale,have been considered the most promising candidate for solar evaporation.However,the simultaneous achievement of high evaporation efficiency and satisfactory tolerance to salt ions in brine remains a challenging scientific bottleneck,restricting the widespread application.Herein,we report ionization engineering,which endows polymer chains of hydrogels with electronegativity for impeding salt ions and activating water molecules,fundamentally overcoming the hydrogel salt-impeded challenge and dramatically expediting water evaporating in brine.The sodium dodecyl benzene sulfonate-modified carbon black is chosen as the solar absorbers.The hydrogel reaches a ground-breaking evaporation rate of 2.9 kg m−2 h−1 in 20 wt%brine with 95.6%efficiency under one sun irradiation,surpassing most of the reported literature.More notably,such a hydrogel-based evaporator enables extracting clean water from oversaturated salt solutions and maintains durability under different high-strength deformation or a 15-day continuous operation.Meantime,on the basis of the cation selectivity induced by the electronegativity,we first propose an all-day system that evaporates during the day and generates salinity-gradient electricity using waste-evaporated brine at night,anticipating pioneer a new opportunity for all-day resource-generating systems in fields of freshwater and electricity.展开更多
Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy storage.However,their widespread commercial application is largely plagued by three major challen...Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy storage.However,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion transfer.To address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions migration.Consequently,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.展开更多
Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinit...Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinity correlates with greater strength and stiffnes,but it can reduce the water-holding capacity.The acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity,both of which have significance as properties of hydrogel filler.The study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid(HCl)and the appropriate hydrolysis time as a filler for film hydrogel.MCC was produced by hydrolyzing cellulose of oil palm empty fruit bunches(OPEFB)with the HCl solution at varied concentrations and periods.The results show that the longer hydrolysis times and higher HCl concentrations increase crystallinity and density while lowering yield and water absorption.The extensive acid hydrolysis reduces the amorphous area significantly,allowing the depolymerization to occur and extend the crystalline area.The morphological properties of the MCC,which are smaller but compact,indicate the presence of disintegrating and diminishing structures.A 2.5 N HCl concentration and a 45-min hydrolysis time succeed in sufficient crystallinity as well as maintaining good water absorption capacity.The treatment produced MCC with absorption capacity of 4.03±0.26 g/g,swelling capacity of 5.03±0.26 g/g,loss on drying of 1.44%±0.36,bulk and tapped density of 0.27±0.031 g/cm^(3) and 0.3±0.006 g/cm^(3),respectively,with a crystallinity index of 88.89%±4.76 and a crystallite size of 4.23±0.70 nm.The MCC generated could potentially be utilized as a hydrogel film filler,since a given proportion will be able to maintain the strength of the hydrogel,not readily dissolve but absorb water significantly.展开更多
Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome gene...Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.展开更多
Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocom...Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.展开更多
To date,hydrogels have gained increasing attentions as a flexible conductive material in fabricating soft electronics.However,it remains a big challenge to integrate multiple functions into one gel that can be used wi...To date,hydrogels have gained increasing attentions as a flexible conductive material in fabricating soft electronics.However,it remains a big challenge to integrate multiple functions into one gel that can be used widely under various conditions.Herein,a kind of multifunc-tional hydrogel with a combination of desirable characteristics,including remarkable transparency,high conductivity,ultra-stretchability,tough-ness,good fatigue resistance,and strong adhesive ability is presented,which was facilely fabricated through multiple noncovalent crosslinking strategy.The resultant versatile sensors are able to detect both weak and large deformations,which owns a low detection limit of 0.1%strain,high stretchability up to 1586%,ultrahigh sensitivity with a gauge factor up to 18.54,as well as wide pressure sensing range(0-600 kPa).Meanwhile,the fabrication of conductive hydrogel-based sensors is demonstrated for various soft electronic devices,including a flexible human-machine interactive system,the soft tactile switch,an integrated electronic skin for unprecedented nonplanar visualized pressure sensing,and the stretchable triboelectric nanogenerators with excellent biomechanical energy harvesting ability.This work opens up a simple route for multifunctional hydrogel and promises the practical application of soft and self-powered wearable electronics in various complex scenes.展开更多
A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regen...A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.展开更多
Water can be used as oxidant in conjunction with metal particles to form metal-water propellant to increase the energy of propellant.For this application,water needs to be stored in form of solid and capable of becomi...Water can be used as oxidant in conjunction with metal particles to form metal-water propellant to increase the energy of propellant.For this application,water needs to be stored in form of solid and capable of becoming liquid when use.Stable and thixotropic hydrogel has good potential as water-retaining material and oxidant of metal-based propellant.In this study,we prepared organic/inorganic composite hydrogels by combining inorganic gellants hectorite and fumed silica with organic gellant agarose,respectively.The total content of the gellants can be reduced to less than 2%by adding agarose.The influence of agarose on water content,phase transition temperature,centrifugal stability and other basic physical properties of composite hydrogels were discussed.The results show that the composite hydrogels have better thixotropy and stability than pure inorganic hydrogels,and the gel-sol transformation can be realized by applying shear force or heating to the phase transition temperature.The composite hydrogels have good shear thinning ability and improved mechanical stability.Fumed silica/agarose hydrogels have better physical stability,while the thixotropy and shear thinning ability of hectorite/agarose hydrogels are better.展开更多
Mesenchymal stem cells(MSC)are particularly effective in promoting cartilage regeneration due to their immunomodulatory,anti-inflammatory and regenerative repair functions of tissues and organs.Meanwhile,the intra-art...Mesenchymal stem cells(MSC)are particularly effective in promoting cartilage regeneration due to their immunomodulatory,anti-inflammatory and regenerative repair functions of tissues and organs.Meanwhile,the intra-articular delivery and synergy with other therapeutic drugs have been the key issues driving their further application.We report a mussel-inspired multifunctional hydrogel system,which could achieve co-delivery and synergism effect of MSC-derived exosomes(Exos)with icariin(ICA).The ICA and Exos co-delivered articular cavity injection system are expected to retain in the joint cavity and promote cartilage regeneration,due to the thermosensitive,self-healing and adhesion properties of the mussel-inspired multifunctional hydrogel.The experimental results proved that Exos enhanced the cellular uptake of ICA by more than 2-fold evenly,and the synergism of Exos and ICA efficiently improve the cell proliferation and migration.After synergic treatment,the content of matrix metalloproteinase 13 in the supernatant and intracellular decreased by 47%and 59%,respectively.In vivo study,ICA-loaded Exos exhibited prolonged retention behavior bymultifunctional hydrogel delivery,thus displayed an increased cartilage protection.In the model of osteoarthritis,co-delivery hydrogel system relieved the cartilage recession,ensuring appropriate cartilage thickness.展开更多
基金Funded by the National Natural Science Foundation of China(No.51873167)the National Innovation and Entrepreneurship Training Program for College Students(No.226801001)。
文摘We developed a fluorescent double network hydrogel with ionic responsiveness and high mechanical properties for visual detection.The nanocomposite hydrogel of laponite and polyacrylamide serves as the first network,while the ionic cross-linked hydrogel of terbium ions and sodium alginate serves as the second network.The double-network structure,the introduction of nanoparticles and the reversible ionic crosslinked interactions confer high mechanical properties to the hydrogel.Terbium ions are not only used as the ionic cross-linked points,but also used as green emitters to endow hydrogels with fluorescent properties.On the basis of the “antenna effect” of terbium ions and the ion exchange interaction,the fluorescence of the hydrogels can make selective responses to various ions(such as organic acid radical ions,transition metal ions) in aqueous solutions,which enables a convenient strategy for visual detection toward ions.Consequently,the fluorescent double network hydrogel fabricated in this study is promising for use in the field of visual sensor detection.
基金supported by the grants from National Research Foundation(NRF,#2021R1A5A2022318,#RS-2023-00220408,#RS-2023-00247485),Republic of Korea.
文摘Inflammatory skin disorders can cause chronic scarring and functional impairments,posing a significant burden on patients and the healthcare system.Conventional therapies,such as corticosteroids and nonsteroidal anti-inflammatory drugs,are limited in efficacy and associated with adverse effects.Recently,nanozyme(NZ)-based hydrogels have shown great promise in addressing these challenges.NZ-based hydrogels possess unique therapeutic abilities by combining the therapeutic benefits of redox nanomaterials with enzymatic activity and the water-retaining capacity of hydrogels.The multifaceted therapeutic effects of these hydrogels include scavenging reactive oxygen species and other inflammatory mediators modulating immune responses toward a pro-regenerative environment and enhancing regenerative potential by triggering cell migration and differentiation.This review highlights the current state of the art in NZ-engineered hydrogels(NZ@hydrogels)for anti-inflammatory and skin regeneration applications.It also discusses the underlying chemo-mechano-biological mechanisms behind their effectiveness.Additionally,the challenges and future directions in this ground,particularly their clinical translation,are addressed.The insights provided in this review can aid in the design and engineering of novel NZ-based hydrogels,offering new possibilities for targeted and personalized skin-care therapies.
基金We acknowledge the support from the National Key Research and Development Program of China(Grant No.2022YFA1405000)the Natural Science Foundation of Jiangsu Province,Major Project(Grant No.BK20212004)+1 种基金the National Natural Science Foundation of China(Grant No.62374083)the State Key Laboratory of Analytical Chemistry for Life Science(Grant No.5431ZZXM2205).
文摘Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.
基金supported by the National Natural Science Foundation of China(Nos.31972929 and 62231025)the Research Program of Shanghai Science and Technology Committee(Nos.21140901300 and 20DZ2220400)+3 种基金the Natural Science Foundation of Chongqing,China(No.CSTB2022NSCQ-MSX0767)the Interdisciplinary Program of Shanghai Jiao Tong University(Nos.YG2021ZD22 and YG2023LC04)the Foundation of National Center for Translational Medicine(Shanghai)SHU Branch(No.SUITM-2023008)the Cross-disciplinary Research Fund of Shanghai Ninth People’s Hospital,Shanghai Jiao Tong University School of Medicine(No.JYJC202108).
文摘A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.
基金The financial support from the National Natural Science Foundation of China (32201179)Guangdong Basic and Applied Basic Research Foundation (2020A1515110126 and 2021A1515010130)+1 种基金the Fundamental Research Funds for the Central Universities (N2319005)Ningbo Science and Technology Major Project (2021Z027) is gratefully acknowledged。
文摘The development of bioinspired gradient hydrogels with self-sensing actuated capabilities for remote interaction with soft-hard robots remains a challenging endeavor. Here, we propose a novel multifunctional self-sensing actuated gradient hydrogel that combines ultrafast actuation and high sensitivity for remote interaction with robotic hand. The gradient network structure, achieved through a wettability difference method involving the rapid precipitation of MoO_(2) nanosheets, introduces hydrophilic disparities between two sides within hydrogel. This distinctive approach bestows the hydrogel with ultrafast thermo-responsive actuation(21° s^(-1)) and enhanced photothermal efficiency(increase by 3.7 ℃ s^(-1) under 808 nm near-infrared). Moreover, the local cross-linking of sodium alginate with Ca^(2+) endows the hydrogel with programmable deformability and information display capabilities. Additionally, the hydrogel exhibits high sensitivity(gauge factor 3.94 within a wide strain range of 600%), fast response times(140 ms) and good cycling stability. Leveraging these exceptional properties, we incorporate the hydrogel into various soft actuators, including soft gripper, artificial iris, and bioinspired jellyfish, as well as wearable electronics capable of precise human motion and physiological signal detection. Furthermore, through the synergistic combination of remarkable actuation and sensitivity, we realize a self-sensing touch bioinspired tongue. Notably, by employing quantitative analysis of actuation-sensing, we realize remote interaction between soft-hard robot via the Internet of Things. The multifunctional self-sensing actuated gradient hydrogel presented in this study provides a new insight for advanced somatosensory materials, self-feedback intelligent soft robots and human–machine interactions.
基金the National Natural Science Foundation of China(11875138,52077095).
文摘High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft electronics.To resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)system.The well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1) at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and adhesion.Additionally,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic devices.The highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output performance.In particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1 mA cm^(-2))and excellent environmental adaptability.This study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.
基金the Natural Science Foundation of China(Grant Nos.82072413,82101649)National Key Research and Development Program of China(Grant Nos.2021YFE0105400).
文摘The integrated repair of bone and cartilage boasts advantages for osteochondral restoration such as a long-term repair effect and less deterioration compared to repairing cartilage alone.Constructing multifactorial,spatially oriented scaffolds to stimulate osteochondral regeneration,has immense significance.Herein,targeted drugs,namely kartogenin@polydopamine(KGN@PDA)nanoparticles for cartilage repair and miRNA@calcium phosphate(miRNA@CaP)NPs for bone regeneration,were in situ deposited on a patterned supramolecular-assembled 2-ureido-4[lH]-pyrimidinone(UPy)modified gelation hydrogel film,facilitated by the dynamic and responsive coordination and complexation of metal ions and their ligands.This hydrogel film can be rolled into a cylindrical plug,mimicking the Haversian canal structure of natural bone.The resultant hydrogel demonstrates stable mechanical properties,a self-healing ability,a high capability for reactive oxygen species capture,and controlled release of KGN and miR-26a.In vitro,KGN@PDA and miRNA@CaP promote chondrogenic and osteogenic differentiation of mesenchymal stem cells via the JNK/RUNX1 and GSK-3β/β-catenin pathways,respectively.In vivo,the osteochondral plug exhibits optimal subchondral bone and cartilage regeneration,evidenced by a significant increase in glycosaminoglycan and collagen accumulation in specific zones,along with the successful integration of neocartilage with subchondral bone.This biomaterial delivery approach represents a significant toward improved osteochondral repair.
基金This work was supported by the Natural Science Foundation of Jiangsu Province(BK20220213)the Fundamental Research Funds of Jiangsu Key Laboratory of Biomass Energy and Material(JSBEM-S-202210 and JSBEM-S-202102).
文摘Solid-state zinc-ion capacitors are emerging as promising candidates for large-scale energy storage owing to improved safety,mechanical and thermal stability and easy-to-direct stacking.Hydrogel electrolytes are appealing solid-state electrolytes because of eco-friendliness,high conductivity and intrinsic flexibility.However,the electrolyte/electrode interfacial contact and anti-freezing properties of current hydrogel electrolytes are still challenging for practical applications of zinc-ion capacitors.Here,we report a class of hydrogel electrolytes that couple high interfacial adhesion and anti-freezing performance.The synergy of tough hydrogel matrix and chemical anchorage enables a well-adhered interface between hydrogel electrolyte and electrode.Meanwhile,the cooperative solvation of ZnCl2 and LiCl hybrid salts renders the hydrogel electrolyte high ionic conductivity and mechanical elasticity simultaneously at low temperatures.More significantly,the Zn||carbon nanotubes hybrid capacitor based on this hydrogel electrolyte exhibits low-temperature capacitive performance,delivering high-energy density of 39 Wh kg^(-1)at-60°C with capacity retention of 98.7%over 10,000 cycles.With the benefits of the well-adhered electrolyte/electrode interface and the anti-freezing hydrogel electrolyte,the Zn/Li hybrid capacitor is able to accommodate dynamic deformations and function well under 1000 tension cycles even at-60°C.This work provides a powerful strategy for enabling stable operation of low-temperature zinc-ion capacitors.
基金supported by the link project of the National Natural Science Foundation of China(52002052 and 22209020)the Key Research and Development Project of Science and Technology Department of Sichuan Province(2022YFSY0004)+2 种基金the Opening project of the State Key Laboratory of New Textile Materials and Advanced Processing Technology(FZ2021009)the Natural Science Foundation of Sichuan Province(2023NSFSC0995)the Natural Science Foundation of Hunan Province(2022JJ30227)。
文摘The anti-freezing strategy of hydrogels and their self-healing structure are often contradictory,it is vital to break through the molecular structure to design and construct hydrogels with intrinsic anti-freezing/self-healing for meeting the rapid development of flexible and wearable devices in diverse service conditions.Herein,we design a new hydrogel electrolyte(AF/SH-Hydrogel)with intrinsic anti-freezing/self-healing capabilities by introducing ethylene glycol molecules,dynamic chemical bonding(disulfide bond),and supramolecular interaction(multi-hydrogen bond)into the polyacrylamide molecular chain.Thanks to the exceptional freeze resistance(84%capacity retention at-20℃)and intrinsic self-healing capabilities(95%capacity retention after 5 cutting/self-healing cycles),the obtained AF/SH-Hydrogel makes the zinc||manganese dioxide cell an economically feasible battery for the state-of-the-art applications.The Zn||AF/SH-Hydrogel||MnO_(2)device offers a near-theoretical specific capacity of 285 m A h g^(-1)at 0.1 A g^(-1)(Coulombic efficiency≈100%),as well as good self-healing capability and mechanical flexibility in an ice bath.This work provides insight that can be utilized to develop multifunctional hydrogel electrolytes for application in next generation of self-healable and freeze-resistance smart aqueous energy storage devices.
基金supported by PLA General Hospital Program,No.LB20201A010024(to LW).
文摘Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.
基金Project supported by the Key Research Project of Zhejiang Laboratory (No.K2022NB0AC03)the National Natural Science Foundation of China (No.11872334)the National Natural Science Foundation of Zhejiang Province of China (No.LZ23A020004)。
文摘Highly entangled hydrogels exhibit excellent mechanical properties,including high toughness,high stretchability,and low hysteresis.By considering the evolution of randomly distributed entanglements within the polymer network upon mechanical stretches,we develop a constitutive theory to describe the large stretch behaviors of these hydrogels.In the theory,we utilize a representative volume element(RVE)in the shape of a cube,within which there exists an averaged chain segment along each edge and a mobile entanglement at each corner.By employing an explicit method,we decouple the elasticity of the hydrogels from the sliding motion of their entanglements,and derive the stress-stretch relations for these hydrogels.The present theoretical analysis is in agreement with experiment,and highlights the significant influence of the entanglement distribution within the hydrogels on their elasticity.We also implement the present developed constitutive theory into a commercial finite element software,and the subsequent simulations demonstrate that the exact distribution of entanglements strongly affects the mechanical behaviors of the structures of these hydrogels.Overall,the present theory provides valuable insights into the deformation mechanism of highly entangled hydrogels,and can aid in the design of these hydrogels with enhanced performance.
基金the National Natural Science Foundation of China(Grant No.52076028).
文摘Interfacial solar evaporation holds immense potential for brine desalination with low carbon footprints and high energy utilization.Hydrogels,as a tunable material platform from the molecular level to the macroscopic scale,have been considered the most promising candidate for solar evaporation.However,the simultaneous achievement of high evaporation efficiency and satisfactory tolerance to salt ions in brine remains a challenging scientific bottleneck,restricting the widespread application.Herein,we report ionization engineering,which endows polymer chains of hydrogels with electronegativity for impeding salt ions and activating water molecules,fundamentally overcoming the hydrogel salt-impeded challenge and dramatically expediting water evaporating in brine.The sodium dodecyl benzene sulfonate-modified carbon black is chosen as the solar absorbers.The hydrogel reaches a ground-breaking evaporation rate of 2.9 kg m−2 h−1 in 20 wt%brine with 95.6%efficiency under one sun irradiation,surpassing most of the reported literature.More notably,such a hydrogel-based evaporator enables extracting clean water from oversaturated salt solutions and maintains durability under different high-strength deformation or a 15-day continuous operation.Meantime,on the basis of the cation selectivity induced by the electronegativity,we first propose an all-day system that evaporates during the day and generates salinity-gradient electricity using waste-evaporated brine at night,anticipating pioneer a new opportunity for all-day resource-generating systems in fields of freshwater and electricity.
基金This work was financially supported by the National Natural Science Foundation of China(52173106 and 22375154).
文摘Aqueous rechargeable Zn-metal batteries(ARZBs)are considered one of the most promising candidates for grid-scale energy storage.However,their widespread commercial application is largely plagued by three major challenges:The uncontrollable Zn dendrites,notorious parasitic side reactions,and sluggish Zn^(2+) ion transfer.To address these issues,we design a sustainable dual crosslinked cellulose hydrogel electrolyte,which has excellent mechanical strength to inhibit dendrite formation,high Zn^(2+) ions binding capacity to suppress side reaction,and abundant porous structure to facilitate Zn^(2+) ions migration.Consequently,the Zn||Zn cell with the hydrogel electrolyte can cycle stably for more than 400 h under a high current density of 10 mA cm^(−2).Moreover,the hydrogel electrolyte also enables the Zn||polyaniline cell to achieve high-rate and long-term cycling performance(>2000 cycles at 2000 mA g^(−1)).Remarkably,the hydrogel electrolyte is easily accessible and biodegradable,making the ARZBs attractive in terms of scalability and sustainability.
基金the Universitas Gadjah Mada’s financial support for this research.This research was conducted using the Final Project Recognition Grant Universitas Gadjah Mada Indonesia Number of 5075/UN1.P.II/DitLit/PT.01.01/2023.
文摘Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinity correlates with greater strength and stiffnes,but it can reduce the water-holding capacity.The acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity,both of which have significance as properties of hydrogel filler.The study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid(HCl)and the appropriate hydrolysis time as a filler for film hydrogel.MCC was produced by hydrolyzing cellulose of oil palm empty fruit bunches(OPEFB)with the HCl solution at varied concentrations and periods.The results show that the longer hydrolysis times and higher HCl concentrations increase crystallinity and density while lowering yield and water absorption.The extensive acid hydrolysis reduces the amorphous area significantly,allowing the depolymerization to occur and extend the crystalline area.The morphological properties of the MCC,which are smaller but compact,indicate the presence of disintegrating and diminishing structures.A 2.5 N HCl concentration and a 45-min hydrolysis time succeed in sufficient crystallinity as well as maintaining good water absorption capacity.The treatment produced MCC with absorption capacity of 4.03±0.26 g/g,swelling capacity of 5.03±0.26 g/g,loss on drying of 1.44%±0.36,bulk and tapped density of 0.27±0.031 g/cm^(3) and 0.3±0.006 g/cm^(3),respectively,with a crystallinity index of 88.89%±4.76 and a crystallite size of 4.23±0.70 nm.The MCC generated could potentially be utilized as a hydrogel film filler,since a given proportion will be able to maintain the strength of the hydrogel,not readily dissolve but absorb water significantly.
基金financial support from the National Natural Science Foundation of China (No. 61801525)the Guangdong Basic and Applied Basic Research Foundation (Nos. 2020A1515010693, 2021A1515110269)+1 种基金the Fundamental Research Funds for the Central Universities, Sun Yatsen University (No. 22lgqb17)the Independent Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-sen University) under grant No. OEMT-2022-ZRC-05。
文摘Growing health awareness triggers the public's concern about health problems. People want a timely and comprehensive picture of their condition without frequent trips to the hospital for costly and cumbersome general check-ups. The wearable technique provides a continuous measurement method for health monitoring by tracking a person's physiological data and analyzing it locally or remotely.During the health monitoring process,different kinds of sensors convert physiological signals into electrical or optical signals that can be recorded and transmitted, consequently playing a crucial role in wearable techniques. Wearable application scenarios usually require sensors to possess excellent flexibility and stretchability. Thus, designing flexible and stretchable sensors with reliable performance is the key to wearable technology. Smart composite hydrogels, which have tunable electrical properties, mechanical properties, biocompatibility, and multi-stimulus sensitivity, are one of the best sensitive materials for wearable health monitoring. This review summarizes the common synthetic and performance optimization strategies of smart composite hydrogels and focuses on the current application of smart composite hydrogels in the field of wearable health monitoring.
基金the financial supports from the National Natural Science Foundation of China(52231007,51725101,11727807,22088101,52271167)the Shanghai Excellent Academic/Technological Leaders Program(19XD1400400)+4 种基金the Ministry of Science and Technology of China(973 Project Nos.2018YFA0209100 and 2021YFA1200600)the Fundamental Research Funds for the Central Universities(2022JCCXHH09)the Foundation for University Youth Key Teachers of Henan Province(2020GGJS170)the Support Program for Scientific and Technological Innovation Talents of Higher Education in Henan Province(21HASTIT004)Key Research Project of Zhejiang Lab(No.2021PE0AC02)。
文摘Hydrogels exhibit potential applications in smart wearable devices because of their exceptional sensitivity to various external stimuli.However,their applications are limited by challenges in terms of issues in biocompatibility,custom shape,and self-healing.Herein,a conductive,stretchable,adaptable,self-healing,and biocompatible liquid metal GaInSn/Ni-based composite hydrogel is developed by incorporating a magnetic liquid metal into the hydrogel framework through crosslinking polyvinyl alcohol(PVA)with sodium tetraborate.The excellent stretchability and fast self-healing capability of the PVA/liquid metal hydrogel are derived from its abundant hydrogen binding sites and liquid metal fusion.Significantly,owing to the magnetic constituent,the PVA/liquid metal hydrogel can be guided remotely using an external magnetic field to a specific position to repair the broken wires with no need for manual operation.The composite hydrogel also exhibits sensitive deformation responses and can be used as a strain sensor to monitor various body motions.Additionally,the multifunctional hydrogel displays absorption-dominated electromagnetic interference(EMI)shielding properties.The total shielding performance of the composite hydrogel increases to~62.5 dB from~31.8 dB of the pure PVA hydrogel at the thickness of 3.0 mm.The proposed bioinspired multifunctional magnetic hydrogel demonstrates substantial application potential in the field of intelligent wearable devices.
基金supported by the National Natural Science Foundation of China(51973166)the Key Research and Development Program of Hubei Province(2020BCA079).
文摘To date,hydrogels have gained increasing attentions as a flexible conductive material in fabricating soft electronics.However,it remains a big challenge to integrate multiple functions into one gel that can be used widely under various conditions.Herein,a kind of multifunc-tional hydrogel with a combination of desirable characteristics,including remarkable transparency,high conductivity,ultra-stretchability,tough-ness,good fatigue resistance,and strong adhesive ability is presented,which was facilely fabricated through multiple noncovalent crosslinking strategy.The resultant versatile sensors are able to detect both weak and large deformations,which owns a low detection limit of 0.1%strain,high stretchability up to 1586%,ultrahigh sensitivity with a gauge factor up to 18.54,as well as wide pressure sensing range(0-600 kPa).Meanwhile,the fabrication of conductive hydrogel-based sensors is demonstrated for various soft electronic devices,including a flexible human-machine interactive system,the soft tactile switch,an integrated electronic skin for unprecedented nonplanar visualized pressure sensing,and the stretchable triboelectric nanogenerators with excellent biomechanical energy harvesting ability.This work opens up a simple route for multifunctional hydrogel and promises the practical application of soft and self-powered wearable electronics in various complex scenes.
基金supported by the National Natural Science Foundation of China,Nos.81620108008(to YQL),31971112(to YQL),82071373(to JC)Innovation Capability Support Program of Shaanxi,No.2021TD-57(to YQL)。
文摘A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.
基金the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘Water can be used as oxidant in conjunction with metal particles to form metal-water propellant to increase the energy of propellant.For this application,water needs to be stored in form of solid and capable of becoming liquid when use.Stable and thixotropic hydrogel has good potential as water-retaining material and oxidant of metal-based propellant.In this study,we prepared organic/inorganic composite hydrogels by combining inorganic gellants hectorite and fumed silica with organic gellant agarose,respectively.The total content of the gellants can be reduced to less than 2%by adding agarose.The influence of agarose on water content,phase transition temperature,centrifugal stability and other basic physical properties of composite hydrogels were discussed.The results show that the composite hydrogels have better thixotropy and stability than pure inorganic hydrogels,and the gel-sol transformation can be realized by applying shear force or heating to the phase transition temperature.The composite hydrogels have good shear thinning ability and improved mechanical stability.Fumed silica/agarose hydrogels have better physical stability,while the thixotropy and shear thinning ability of hectorite/agarose hydrogels are better.
文摘Mesenchymal stem cells(MSC)are particularly effective in promoting cartilage regeneration due to their immunomodulatory,anti-inflammatory and regenerative repair functions of tissues and organs.Meanwhile,the intra-articular delivery and synergy with other therapeutic drugs have been the key issues driving their further application.We report a mussel-inspired multifunctional hydrogel system,which could achieve co-delivery and synergism effect of MSC-derived exosomes(Exos)with icariin(ICA).The ICA and Exos co-delivered articular cavity injection system are expected to retain in the joint cavity and promote cartilage regeneration,due to the thermosensitive,self-healing and adhesion properties of the mussel-inspired multifunctional hydrogel.The experimental results proved that Exos enhanced the cellular uptake of ICA by more than 2-fold evenly,and the synergism of Exos and ICA efficiently improve the cell proliferation and migration.After synergic treatment,the content of matrix metalloproteinase 13 in the supernatant and intracellular decreased by 47%and 59%,respectively.In vivo study,ICA-loaded Exos exhibited prolonged retention behavior bymultifunctional hydrogel delivery,thus displayed an increased cartilage protection.In the model of osteoarthritis,co-delivery hydrogel system relieved the cartilage recession,ensuring appropriate cartilage thickness.
