There has been increasing public interest in physical and mental health in recent years, rendering high-performance flexible sensors a burgeoning research focus. However, currently available hydrogel sensors fail to achieve high stretchability, conductivity, and stability. In this study, polyacrylamide (PAM) served as the matrix, and a dual-cellulose hierarchical network (MCNF) was constructed using microfibrillated cellulose and TEMPO-oxidized cellulose nanofibers of differing dimensions through a photocuring method. MXene was then loaded onto this network to form an effective conductive path. This approach endowed the hydrogel with a new energy dissipation mechanism, enhancing its mechanical properties: tensile strength (116.86-277.84 kPa), strain (1923-2029%), and toughness (1.34-2.12 MJ m-3). Additionally, the electrical conductivity of the PCMH hydrogel can reach 4.55 S m-1 and still maintain 64% of its conductivity at -70 °C, demonstrating excellent freeze resistance. Finally, when used as a flexible sensor, it can stably and sensitively monitor the movement signals of various parts and joints of the human body, accurately identify different sounds, and expand the application of cellulose in multifunctional sensors, soft electronic devices, and skin patches.

Hydrogels, a typical solid-liquid hybrid material, have shown great potential in wearable electronics, tissue engineering, and other fields; however, their underwater applications have long been limited by the 'swelling-weakening 'effect. To address this challenge, this study proposes a 'bacterial cellulose (BC) synergistic reverse -dialysis-induced confined dense network 'strategy to construct a BP-RD hydrogel with high water content and excellent mechanical-functional properties through a one-step approach. The design innovatively uses the reverse dialysis process to drive dual dynamic assembly. First, polyethylene glycol-mediated water extraction compresses the BC network to form a rigid confined space. Then, polyvinyl alcohol molecules move and crystallize in the BC framework, creating a dense interpenetrating network. At 75% moisture content, the material achieved 22 MPa fracture strength, 145 MJ m-3 toughness, and 1.58 S m-1 conductivity owing to the confinement effect. Additionally, it showed outstanding antiswelling characteristics (the tensile strength increased by 14% after 7 days). This method can also be applied to combine existing hydrogels in one step, creating a double-layer hydrogel structure with improved mechanical properties and swelling performance. This approach solves the key problems of the failure of traditional hydrogels to expand, the cumbersome preparation process, and the difficulty in meeting the performance requirements of multiple scenarios.

Climate change has led to alternating periods of heavy rainfall and drought, which expose mulberries to the dual pressures of sclerotinia disease and drought. In this study, a dual-functional nanoformulation, pterostilbene@nanoenzyme complex (PTE@ZIF-8@MgHCF), was prepared to control mulberry sclerotinia disease and enhance drought tolerance in mulberry. This nanoformulation (PTE concentration is 500 μM) exhibited growth inhibition rates up to 95.30% against Ciboria shiraiana and could eventually cause death of fungal cells by destroying the cell membrane. Additionally, PTE@ZIF-8@MgHCF exhibited excellent antioxidant activity. Under drought conditions, it effectively eliminated excess hydroxyl radicals, thereby protecting the photosynthetic process, which is crucial for starch production. Starch effectively maintains the osmotic pressure of cells and reduces water loss. Finally, PTE@ZIF-8@MgHCF did not exert toxic effects on wheat plants or earthworms. In conclusion, the nanoformulation is expected to greatly aid the effective control of mulberry sclerotinia disease and enhance drought resistance in mulberry.

Bioreactors play a crucial role in biocatalysis, particularly where energy efficiency and catalytic stability remain critical challenges. This study reports a continuous-flow photothermal bioreactor based on a MXene/covalent organic framework (MCOF) composite, synthesized in one pot with high surface area and excellent photothermal biocatalytic performance. Multilayer MCOF membranes with nanoscale confinement effects were constructed, which enabled highly efficient enzyme immobilization and enhanced mass transfer. Under near-infrared light irradiation, the MCOF membrane rapidly converted light into heat, facilitating efficient thermal management of enzymes. Compared to the conventional heat conduction heating method, this system reduced energy consumption by more than 86%, requiring only 2.14 Wh of energy per hour. Additionally, the confined structure of the MCOF membrane promoted substrate-enzyme interactions and continuous-flow catalysis. To achieve the same product-conversion effect, the confined structure required only 45% of the free enzyme reaction time and 55% of the dispersed MCOF powder reaction time. After six cycles, the MCOF bioreactor retained over 80% catalytic activity and maintained high conversion rates under various flow conditions. This work integrates photothermal management and confinement-enhanced catalysis to establish a new strategy for developing efficient, reusable, and low-energy bioreactors suitable for scalable green biomanufacturing.

The prevention of spoilage of meat products is a key aspect of food preservation. In this study, TEMPO-oxidized cellulose nanofibers (TOCNF), polyvinyl alcohol (PVA), chitosan (CS), and mulberry anthocyanins (MA) were employed as raw materials to prepare the environment-friendly and multifunctional PCT0.4-MA (PVA/CS/TOCNF0.4-MA) hydrogel. At low temperatures, PCT0.4-MA hydrogel ice cubes effectively reduced the temperature of food products achieving a cooling efficiency, thereby allowing the cooling and preservation of meat products. Moreover, the PCT0.4-MA hydrogel exhibited excellent mechanical properties (compressive and tensile strengths of 0.19 and 0.79 MPa, respectively). The PCT0.4-MA hydrogel was found to be suitable for packaging and extending the shelf life of refrigerated chicken breast. Moreover, the PCT0.4-MA hydrogel exhibited effective antibacterial activities on the test bacteria Staphylococcus aureus and Escherichia coli, while effectively prolonging the shelf life of refrigerated chicken to more than 6 days. Therefore, the PCT0.4-MA hydrogel can be applied for food packaging to extend the shelf life of refrigerated meat products. Due to its advantages of simple preparation and low cost, the hydrogel is suitable for various applications in the food processing industry.

Immobilized enzyme catalytic reactions reduce pollution and enable enzyme reuse, making them suitable for industrial biocatalysis. However, immobilized enzymes often face mass-transfer limitations and restricted substrate access to active sites, which lowers catalytic efficiency. To address these challenges, this study developed a Marangoni-poly(N-isopropylacrylamide) (Marangoni–PNIPAM) hydrogel rotor bioreactor (MPR) through compartmentalized photopolymerization and covalent organic framework (COF)-based immobilization of β-glucosidase. The MPR reached a maximum rotation speed of 4,319 rpm, sustained rotation for 22 min, and exhibited a maximum reaction rate (Vmax) of 1.35 mM·min-1. It converted 87.2% of the substrate within 30 min, demonstrating high catalytic efficiency. Performance decreased markedly upon scale-up. By integrating multiple rotors into a spin-array configuration, the arrayed MPR (AMPR) achieved a conversion rate of 97.3%. Furthermore, it maintained 90% efficiency in scaled-up systems—a level more than four times higher than that of the single-rotor MPR and representing a 197% improvement over COF@β-G. Simulation analyses showed that the AMPR generates vortices through both rotor self-rotation and inter-rotor interactions, promoting fluid movement that equalizes substrate concentration and accelerates transport to the carrier surface. In addition, the induced fluid disturbances enhance substrate penetration through intricate pore channels, allowing access to enzymatic active sites, thereby accelerating conversion.

Bacterial cellulose (BC) is employed as a toughening agent in the preparation of composite hydrogels. However, achieving both high strength and toughness after incorporating BC into hydrogels remains challenging. Insufficient amounts of BC limit the enhancement of strength, whereas excessive BC results in reduced elongation of hydrogels. Herein, a fiber salting-out method was developed to fabricate BC/polyvinyl alcohol (PVA) hydrogels by modifying BC with Hofmeister series ions (-COO-, -PO32-, -SO3-). Through the fiber salting-out effect of BC, PVA was induced to aggregate on the BC surface, forming more crystalline domains and thereby improving the mechanical properties of the hydrogels. Among them, the tensile strength and toughness of the SBCP hydrogel (BC modified with -SO3-) reached the highest values, measuring 2.98 MPa and 27.48 MJ m-3, respectively-representing 9-fold and 36-fold increases over those of pure PVA hydrogels. Furthermore, this hydrogel exhibits high electrical conductivity and favorable biocompatibility. This study presents a new strategy for fabricating tough BC-based hydrogels and provides insight into new applications for BC fibers.

Ion-conductive hydrogels show great potential for wearable sensing, human motion monitoring, and soft robotics because of their high stretchability, flexibility, and conductivity. However, conventional ion-conductive hydrogels are prone to swelling under water, compromising the mechanical properties and conductivity of hydrogel sensors, thereby severely limiting their underwater applications. Consequently, developing underwater hydrogel sensors with excellent antiswelling and sensing properties remains a substantial challenge. This study introduces a noncovalent interactions–reverse dialysis synergistic driving method to fabricate antiswelling, ion-conductive hydrogels. Polyvinyl alcohol (PVA) spontaneously aggregates and entangles around silk nanofibers (SNFs) via noncovalent interactions, and reverse dialysis reduces the distance between SNFs and PVA chains, resulting in a dense network of hydrogen bonds. The tensile strength of the prepared Rd-S3P5 hydrogel (SNFs to PVA mass ratio of 3:5, 2.6 MPa) was 13 times that of the freeze–thaw hydrogel (0.2 MPa). Furthermore, the hydrogel exhibited outstanding antiswelling properties (equilibrium swelling ratio of 1.1%), ionic conductivity (8.2 S m−1), and sensitivity (GF = 1.89, within a strain range of 100%–250%). Subsequently, an underwater strain sensor based on the hydrogel was developed to monitor underwater movements, demonstrating its substantial potential in underwater flexible devices and expanding the potential applications of wearable electronic devices.

Ciboria shiraiana (C. shiraiana), a pathogenic fungus, is a major threat to mulberry trees, causing mulberry sclerotinia diseases. Current control strategies primarily rely on chemical pesticides, whose long-term use leads to adverse effects such as pesticide residues, environmental pollution, and pathogen resistance. This study aimed to develop a green pesticide derived from the essential oil (EOs) of Solidago canadensis L. (S. canadensis L.) and to analyze its antifungal mechanism. SLEOs were extracted from flowers, leaves, and stems of S. canadensis L. via hydro-distillation. Their chemical composition was analyzed by GC-MS. Multivariate statistical analysis was used to assess compositional differences among SLEOs from various plant parts and evaluate the correlation between their chemical components and antifungal efficacy. The antifungal mechanism of SLEOs against C. shiraiana was investigated using an integrated approach combining transcriptomics with physiological and biochemical analyses. The EO yield varied with plant part: flowers yielded the most (1.00% ± 0.07%), followed by leaves (0.76% ± 0.04%) and stems (0.05% ± 0.01%). Flower EOs (FEOs) strongly inhibited C. shiraiana, with an EC50 value of 0.642 μL/mL. α-pinene and myrcene showed the highest correlation with antifungal activity. Transcriptomic and physiological data revealed that SLEOs compromise cell wall and membrane integrity, infiltrate cells, and trigger leakage of intracellular contents. Additionally, SLEOs inhibited activities of antioxidant enzymes (SOD, CAT, and POD), leading to intracellular ROS accumulation, oxidative stress, lipid peroxidation, and DNA damage. SLEOs constitute a promising natural and environmentally sustainable antifungal agent. Their activity is linked to specific components and a multi-target mechanism involving membrane disruption and oxidative stress induction. This study provides a foundation for developing plant-based agents to manage mulberry sclerotinia diseases.

Hydrogels are important biomaterials that have vital applications in multiple fields. The effective preparation of tough hydrogels that meet the requirements of multifunctional application remains a great challenge. Inspired by the water absorption and loss across cell membranes in nature, a novel strategy of reverse dialysis (external hydrophilic substance regulates the structure of internal polymer) was proposed. The strategy involves regulating the difference in internal and external osmotic pressure, which, in turn, regulates the hydrogen bond formation in the polymer chain. Compared to the traditional methods of hydrogel preparation, the preparation time in this study is restricted to within 3 h. During the reverse dialysis process, nanofiber-like structures were successfully formed inside the hydrogel. Especially at low concentrations of PVA (5 % w/v), ordered fiber structures are formed. The tensile strength and toughness can be modulated within the approximate range of 0.24-41.52 MPa and 1.42-222.62 MJ/m3, respectively. The hydrogel was found to exhibit good biocompatibility, ionic conductivity (up to 7.80 S/m), and frost resistance; it can be employed in supercapacitors as a solid electrolyte. The reverse dialysis method described in this study provides a sound framework for the preparation of strong and tough hydrogels with multifunctional applications.

In recent years, flexible-hydrogel wearable devices have undergone rapid development while photothermal therapy, energy storage/conversion, and other fields have been widely developed and used. However, the poor mechanical properties of hydrogels can affect their stability and reliability in practical applications, and it is often difficult to achieve both excellent mechanical properties and multifunctional characteristics. This study prepared a hierarchical cellulose network/PVA multifunctional composite hydrogel (MCPH) using cellulose nanofiber as fine fibers and microfibrillated cellulose as coarse fibers. The hierarchical cellulose network provides tensile strength as a skeleton while the PVA serves as the soft matrix to assist energy dissipation, which provides the composite hydrogel with good mechanical properties (toughness of 1.21 MJ m-3 and tensile modulus of 2.20 MPa). In addition, owing to hierarchical cellulose network preventing excessive stacking of MXene while achieving stable series connection of nano fillers, MCPH exhibits excellent photothermal conversion rate, photothermal antibacterial ability (viability of Escherichia coli and Staphylococcus aureus < 0.88 %), and energy storage capacity (6886 mF/cm2). Thus, this study not only prepared a composite hydrogel with good mechanical properties and excellent multifunctional properties but also expanded the application potential of cellulose, an important green renewable plant resource, in high-value-added wearable products.

In recent years, many strategies have been developed to enhance the mechanical properties of hydrogels. However, due to the complex process, the addition of non-green crosslinking agents and the use of high concentration salt solutions these strategies lead to increased costs, resource waste and environmental pollution. In addition, the synergistic improvement of strength and toughness of hydrogels is still challenging. Herein, a general green strategy of solid salting-out to improve the strength and toughness of physical hydrogels is reported. This strategy can induce the directional transfer of water molecules in the hydrogel, promoting the close layer-by-layer self-assembly of the PVA molecular chain. Compared with liquid salting-out, solid salting-out has a more significant improvement in the strength of hydrogels, and solid salt blocks can be recycled and reused. A PVA hydrogel prepared by the solid salting-out method showed both high strength and toughness that were 1962- and 1900-fold those from before solid salting-out, respectively. The strength and toughness of the hydrogel can be further improved to 109.06 MPa and 125.73 MJ m-3, respectively, by inducing the collaborative self-assembly of cellulose nanofibers and PVA molecular chains. As a general strategy, solid salting-out could enhance various physical hydrogels composed of materials such as silk, gelatin, and cotton staple cellulose. Thus, this study not only provides a simple method for the strengthening and toughening of physical hydrogels but also has potential applications in the field of biological implants because of the favorable biocompatibility of the prepared hydrogels.

Flexible pressure sensors are known for their excellent comprehensive performance, making them suitable for a wide range of applications, including in human-machine interfaces, health monitoring, motion detection, wearable electronics, medical devices, and soft robotics. However, the preparation of silk nanofibers (SNFs)based aerogel sensors with optimal resilience remains challenging. Herein, the SNF/ polyvinyl alcohol (PVA)/ MXene composite aerogel was prepared via freeze-drying using SNF, MXene and PVA as raw materials. In this study, PVA was innovatively used as a binder to connect dispersed SNFs, which improved the resilience and mechanical properties of aerogel. The resulting composite aerogel can function as a pressure sensor that exhibits excellent efficacy owing to the synergies among its various components, achieving an impressive gauge factor of 24.61 at a compression strain of 40 %-50 %. The composite aerogel-based sensors also exhibited a rapid response time (load 100 ms, recovery 200 ms), and good stability (1000 cycles). They demonstrated a quick response to pressure and strain signals, enabling them to accurately monitor various human activities such as sound detection, wrist and finger movements, and knee bending.

Noble metal nanoparticles have been widely used in catalysis, environmental studies, and other fields. However, the loading of noble metals is challenging because of their unfavorable mass transfer. Herein, a simple, green dual-template method was developed for the synthesis of a Marangoni cellulose hydrogel rotor catalytic reactor (MCR). The rotor had a two-component asymmetrical network structure, which was constructed via different crosslinking methods and enabled the MCR to achieve a fast (6190 r/h) and prolonged (25 min) rotation. In addition, we propose a new refueling method, which only requires 80uL solvent to continue to drive the rotor for over 13 min, effectively prolonging the rotation time of the rotor. During rotation, the speed of the catalyst was greater than that of the substrate, which is conducive for the entry of the substrate into the reactor channel. The spin-induced fluid disturbance promoted substrate replenishment around the catalyst, thereby improving the mass-transfer efficiency and increasing the primary kinetic constant to 16.5-fold of that of the stationary hydrogel while maintaining stability. Therefore, the MCR proposed in this study offers a novel approach for improving the catalytic mass-transfer efficiency of precious metals and exhibits potential application value in remediating environmental pollution and catalysis.

Flexible electronic sensors that can capture subtle physical, chemical and biological signals and generate real-time stimulus responses are of great importance in the fields of human-computer interaction, biomedicine, etc. Herein, a multifunctional sensing hydrogel was developed by tightly adhering two-dimensional rigid conductive MXene nanosheets to the surface of vimineous silk nanofibers (SNFs) and assembling them into an SNF@MXene network structure. Polyvinyl alcohol (PVA) was then in situ polymerized in SNF@MXene as a filling matrix. MXene nanosheets were attached to the SNF network skeleton, avoiding the settlement and aggregation of MXene and forming a PSM composite hydrogel with a uniform and dense conductive network. The designed PSM hydrogel-based sensor showed excellent mechanical properties (tensile strength = 5.07 MPa), wide operating range (700.6 %), high sensitivity (gauge factor = 8.2), high electrical conductivity (1.64 S m-1), and adhesion. The sensor could detect various physiological activities of the human body. In addition, it also showed the application potential in speech recognition, capacitive pen, etc. PSM exhibited excellent photothermal conversion efficiency. It could be rapidly heated to 82.8 °C under NIR irradiation and used for photothermal therapy. This study provides a simple conductive network design strategy for the fabrication of flexible electronic devices with multiple functions.

Hydrogels are three-dimensional network materials that have vast application potential in bone tissue engineering given their unique physical and chemical properties. However, compared with natural bones, the mechanical strength and stiffness of existing hydrogels are difficult to meet the requirements of mechanical support in bone repair at load-bearing sites. Inspired by biomineralization and semipermeable cell membrane osmotic pressure regulation, herein, the organic-inorganic mineralized copolymer (SNF/CaP) was introduced into a polyvinyl alcohol (PVA) network and unilateral reverse dialysis was used to regulate the interaction between the PVA chains and SNF/CaP to improve the mechanical properties of the hydrogel. The effects of different pH conditions on the type of calcium phosphate formed on silk nanofibers were studied. Under mineralization conditions of pH 5 and unilateral reverse dialysis, the prepared nanofiber mineralized PVA (PSH) hydrogel exhibited a densely layered structure. The tensile strength and toughness of the prepared PSH hydrogels could reach 70.87 MPa and 309.07 MJ/m3, respectively, which were 3.77 times and 3.30 times higher than those of PVA hydrogels (only PVA by unilateral reverse dialysis) and PS hydrogels (PVA and silk nanofibers by unilateral reverse dialysis), respectively. The mechanical properties of the PSH hydrogels following water absorption balance still matched those of human cartilage (8.1-40 MPa) and were better than most of the reported PVA-based hydrogels. In addition, the PSH hydrogel demonstrated excellent biocompatibility and has potential application value in cartilage tissue engineering.

Bioreactors are crucial in industrial production, where enzyme catalysis typically occurs in water and requires continuous heating, consuming significant energy. This study reports a new type of precisely heated reactor constructed from cellulose and MXene with directional channels and porous inner walls. MXene forms directional channels with cellulose via layered stacking, enabling rapid heat conduction and accurate heat transference to the enzyme catalyst. A temperature control box monitors the reactor's temperature and uses automated heating to reduce energy loss. The reactor's porous structures facilitate faster fluid diffusion, improving the "disturbance" effect. Compared to traditional methods, which heat the entire aqueous solution, this reactor accelerates heat and mass transfer processes, enhancing catalytic performance. The reactor can quickly raise the temperature around the enzyme to 60 degrees C within 100 s and achieve a 98.12 % conversion rate for polydatin within 2 h, significantly higher than the traditional method (89.84 %). The layered MXene reactor structure reduces energy consumption by over 76 %, with total electrical energy consumption of 3.33 Wh compared to 14.33 Wh in traditional methods. This reactor is suitable for continuous-flow catalysis with low energy consumption and excellent cyclic storage stability, offering a new approach for constructing precise temperature-controlled bioreactors.

Although hydrogels show immense promise in biomedical and engineering applications, they face critical limitations in mechanical property versatility and inadequately stable anti-swelling capacities. Inspired by the graded structure of articular cartilage-where a dense, wear-resistant outer layer integrates with a compliant, shock-absorbing inner layer-this study proposes a dual-stage reverse-dialysis strategy for fabricating a chitosan/ polyvinyl alcohol (CS/PVA) and silk nanofiber/polyvinyl alcohol (SNF/PVA) double-layer biomimetic hydrogel by precisely regulating the internal dialysate (a CS/PVA solution), external polyethylene glycol concentration, and molecular weight to form a soft inner structure. Subsequently, a rigid, densely structured SNF/PVA outer layer was fabricated without requiring any chemical crosslinkers, synergistically enhancing the mechanical property of the hydrogel: The compression strength surged from 345.07 to 2490.23 kPa (for the single inner and double layers, respectively) at 70 % strain by optimizing the solution concentration and enhancing the mechanical properties of the outer hydrogel. Crucially, this method enables robust, chemical-crosslinker-free interfacial bonding (shear strength >390 kPa) through physical crosslinking, overcoming weak interlayer adhesion in conventional methods. The hydrogel exhibits exceptional anti-swelling properties (mass swelling ratio = 24.55 % after 168 h) and resilience (91.47 % stress retention over 10 compression cycles). This strategy provides a green and scalable route to develop structurally stable, double-layer hydrogels.