Search

Patients with metabolic syndrome (MetS) undergoing surgery are at high risk of developing peritoneal adhesions and other severe postoperative complications. However, the single shielding function and absence of physiological activity render conventional methods less useful in preventing adhesions in patients with MetS. To address this challenge, a convenient method is introduced for developing a novel tissue-adhesive hydrogel called oxidized dextran-metformin (ODE-ME) via Schiff base linkages. This injectable ODE-ME hydrogel exhibits excellent tissue-adhesive properties and various physiological functions, particularly enhanced antibacterial effects. Furthermore, in vivo experiments demonstrate that the hydrogel can effectively alleviate hyperglycemia, reduce excessive inflammation, and improve fibrinolytic activity in MetS mice, thereby preventing adhesions and promoting incisional healing. The hydrogel concurrently isolates injured tissues and lowers the blood glucose levels immediately after surgery in mice. Therefore, the ODE-ME hydrogel functions as a multifunctional barrier material and has potential for preventing postoperative peritoneal adhesions in patients with MetS in clinical settings., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Conductive hydrogels (CHs) have attracted considerable attentions in the fields of wearable electronics, disease diagnosis, and artificial intelligence. However, it is still a great challenge to prepare a single CH system with integrated characteristics of high stretchability, good transparency, and multisensory function through a simple fabrication process. Herein, carboxylic cellulose nanofibers (CCNF) were used to assist the homogeneous distribution of opaque conductive poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) into the crosslinked polyacrylamide network for the fabrication of stretchable and transparent interpenetrating network CH, aiming for a high-performance multisensory system. As expected, the ready formation of hydrogen bonds between the water molecules and a great deal of hydrophilic groups in the hydrogel endow the obtained CH with excellent humidity response behavior in a wide range (0-85%), and the introduction of CCNF and PEDOT: PSS is proved to be an effective strategy to enhance the humidity sensitivity, exhibiting great potential for the noncontact sensing of human respiration and finger movement. Meanwhile, it also displays excellent strain sensing behavior with favorable sensitivity in a broad range (0-837 %), fast response and reliable stability and reproducibility. Importantly, our prepared CH can also detect and discriminate complicated human activities and physiological signals. All these demonstrate the superiority of our prepared CH for the new generation of flexible wearable electronics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Clinically, increasing the peritoneal barrier is an effective adjunct to reducing postoperative peritoneal adhesion. This study presents a facile template for preparing a supramolecular hybrid hydrogel through dynamic covalent cross-linking between carboxymethyl chitosan (CMCS), 2-formylphenylboronic acid (2-FPBA), and quercetin (Que). The as-prepared complex CMCS/2-FPBA/Que (CFQ) hydrogel exhibited favorable antibacterial, anti-inflammatory, and antioxidant effects. A L929 cytotoxicity evaluation confirmed the favorable cytocompatibility of the CFQ hydrogel. The postoperative anti-adhesion ability of the CFQ hydrogel was further evaluated in rats with lateral wall defects and cecal abrasions. Compared with control groups, the tissue adhesion rate was significantly reduced by increasing the Que concentration in all the hydrogel-treated groups. Additionally, the sustained-release time of the C3F0.8Q0.08 hydrogel can exceed 14 days, which is highly desirable for clinical wound treatment. STATEMENT OF SIGNIFICANCE: Postoperative adhesions are a very common postoperative complication that seriously affects the quality of life of patients. The currently commonly used methods for preventing adhesion mainly use degradable barrier materials for physical separation. In this study, we prepared a dual dynamic covalently cross-linked CFQ hydrogel, which is not only degradable and injectable, but also has multiple properties such as antibacterial, antioxidant and anti-inflammatory, which can effectively prevent postoperative adhesion and promote wound healing., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier Ltd.)

Zn metal anode suffers from dendrite issues and passive byproducts, which severely plagues the practical application of aqueous Zn metal batteries. Herein, a polyzwitterionic cross-linked double network hydrogel electrolyte composed of physical crosslinking (hyaluronic acid) and chemical crosslinking (synthetic zwitterionic monomer copolymerized with acrylamide) is introduced to overcome these obstacles. On the one hand, highly hydrophilic physical network provides an energy dissipation channel to buffer stress and builds a H2O-poor interface to avoid side reactions. On the other hand, the charged groups (sulfonic and imidazolyl) in chemical crosslinking structure build anion/cation transport channels to boost ions' kinetics migration and regulate the typical solvent structure [Zn(H2O)6]2+ to R-SO3− [Zn(H2O)4]2+, with uniform electric field distribution and significant resistance to dendrites and parasitic reactions. Based on the above functions, the symmetric zinc cell exhibits superior cycle stability for more than 420 h at a high current density of 5 mA·cm−2, and Zn∥MnO2 full cell has a reversible specific capacity of 150 mAh·g−1 after 1000 cycles at 2 C with this hydrogel electrolyte. Furthermore, the pouch cell delivers impressive flexibility and cyclability for energy-storage applications. [ABSTRACT FROM AUTHOR]

Efficient and selective extraction of uranium (U(VI)) from seawater is essential for sustainable nuclear power production. This study reports a novel adsorbent zeolitic imidazolate framework (ZIF)-67@SiO2-A/polyacrylamide (PAM) which was synthesized by grafting the core–shell metal–organic frameworks (MOFs)-based nanostructures coated with the 3-aminopropyl triethoxysilane (APTES) functionalized SiO2 (SiO2-A) onto PAM hydrogel. The SiO2 shell was grown on the surface of MOF, which improved the acid-base resistance of MOF. The introduction of ZIF-67@SiO2-A enhances the specific surface area and adsorption efficiency of the PAM. The ZIF-67@SiO2-A/PAM shows remarkable adsorption capacity, fast adsorption kinetics, and good reusability for uranium. It has excellent adsorption property (6.33 mg·g−1, 30 d) in natural seawater. The X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), energy dispersive spectroscopy (EDS) mappings, and density functional theory reveal that the coordination by N and O in ZIF-67@SiO2-A/PAM with uranium is the main mechanism of uranium adsorption. Thus, ZIF-67@SiO2-A/PAM has great potential to capture uranium from natural seawater. [ABSTRACT FROM AUTHOR]

In this study, graphene oxide (GO) and polyacrylamide/polyacrylic acid (PAM/PAA) are used to prepare hydrogels with photothermal conversion properties for highly efficient uranium extraction from seawater. Zwitterionic 2‐methacryloyloxy ethyl phosphorylcholine (MPC) is introduced in the PAM/PAA/GO hydrogel to obtain PAM/PAA/GO/MPC (PAGM), exhibiting good antibacterial properties. PAGM demonstrates efficient and specific adsorption of uranium (VI) (U(VI)). Under light conditions, the adsorption capacity of PAGM reaches 196.12 mg g−1 (pH = 8, t = 600 min, C0 = 99.8 mg L−1, m/v = 0.5 g L−1). The adsorption capacity is only 160.29 mg g−1 under dark conditions (pH = 8, t = 600 min, C0 = 99.8 mg L−1, m/v = 0.5 g L−1). The adsorption capacity of light is 22.5% higher than that of dark. The adsorption process is fitted using the Langmuir and pseudo‐second‐order models. Furthermore, PAGM exhibits good repeatability and stability after five adsorption–desorption cycles. PAGM exhibits a U(VI) adsorption capacity of 6.1 mg g−1 after storage for one month in natural seawater. The X‐ray photoelectron spectroscopy (XPS) results demonstrate that the coordination of the amino, carboxyl, and hydroxyl groups with U(VI) is the primary mechanism of U(VI) adsorption. The mechanism is confirmed through detailed density functional theory calculations. PAGM demonstrates durability, high efficiency, photothermal conversion properties, and antibacterial properties. Thus, it is a promising candidate for uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

Efficient capture of uranium(VI) (U(VI)) from seawater is of great significance to the sustainable development of nuclear energy and environmental protection, which is also a serious challenge at present. In this study, hollow Zn/Co zeolitic imidazolate framework (H-ZIF) was decorated on polyacrylamide/sodium alginate (PAM/SA) hydrogel by chelating and covalently crosslinking, and a new type of PAM/SA/H-ZIF hydrogel was synthesized. The combination of PAM/SA and H-ZIF gives PAM/SA/H-ZIF hydrogel excellent mechanical properties, good stability, and abundant surface functional groups, which is beneficial to improving the adsorption properties. The extraction amount of U(VI) by PAM/SA/H-ZIF is 171.14 mg·g−1 at C0 = 99.52 mg·L−1 and pH = 5.0. The adsorption equilibrium is reached in 120 min and the adsorption process fits well with Langmuir isotherm model and pseudo-second-order rate equation. The PAM/SA/H-ZIF also showed good recyclability and stability after 10 cycles of adsorption—desorption. More importantly, the rate of uranium adsorption is 0.196 mg·g−1·day−1 after 30 days, which implies that the PAM/SA/H-ZIF could serve as a potential adsorbent for the development of uranium capture from seawater. [ABSTRACT FROM AUTHOR]

Hydrogels have been widely applied in the fields of biology, medicine, soft materials and flexible/wearable devices owing to their superior biocompatibility and their versatile physicochemical properties. Although multiple chemical and physical methods have been proposed to functionalize hydrogels, endowing hydrogels with multi-properties/functionalities utilizing few components is still a challenge. This paper describes a simple and effective method to functionalize polymeric hydrogels with carboxymethyl cellulose (CMC) modified Fe3O4 nanoparticles (CMC@Fe3O4 NPs). The as-prepared metallogels exhibit good self-healing ability, ionic conductivity, photo-thermal transformability and magnetic field responsiveness. A triple functional sensor was built up to prove the universal viability of this metallogel toward functional devices. [ABSTRACT FROM AUTHOR]

Conductive hydrogels are gaining significant attention as promising candidates for the fabrication materials for flexible electronics. Nevertheless, improving the tensile properties, hysteresis, durability, adhesion, and electrochemical properties of these hydrogels remains challenging. This work reports the development of a novel semi‐interpenetrating network poly(ionic liquid) hydrogel named PATV, via the in situ polymerization of acrylamide, N‐[Tris(hydroxymethyl)methyl] acrylamide, and 1‐vinyl‐3‐butylimidazolium tetrafluoroborate. The density functional theory calculations reveal that the poly(ionic liquid) in the hydrogel network acts as physical cross–linking points to construct hydrogen‐bond networks. Furthermore, the hydrogen‐bond networks dissipate energy efficiently and quickly, and thus stress concentration and hysteresis are avoided. The prepared hydrogel has a low hysteresis (9%), high tensile properties (900%), fast response (180 ms), high sensitivity (gauge factor = 10.4, pressure sensitivity = 0.14 kPa−1), and wide sensing range (tensile range: 1–600%, compression range: 0.1–20 kPa). A multifunctional sensor designed based on the designed hydrogel enables real‐time, rapid, and stable response‐ability for the detection of human movement, facial expression recognition, pronunciation, pulse, handwriting, and Morse code encryption. Furthermore, the assembled triboelectric nanogenerator displays an excellent energy harvesting capability, thus highlighting its potential application in self‐powered flexible wearable electronic devices. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOF)-polymer hybrid hydrogel solves the processable forming of MOF powder and energy consumption of uranium extraction. However, the hybrid hydrogel by conventional synthesis methods inevitably lead to MOF agglomeration, poor filler-polymer interfacial compatibility and slowly adsorption. Herein, we designed that ZIF-67 was implanted into the carboxymethyl cellulose/polyacrylamide (CMC/PAM) by network-repairing strategy. The carboxyl and amino groups on the surface of CMC/PAM drive the uniform growth of ZIF-67 inside the CMC/PAM, which form an array of oriented and penetrating microchannels through coordination bonds. Our strategy eliminate the ZIF-67 agglomeration, increase the interfacial compatibility between MOF and polymer. The method also improve the free and fast diffusion of uranium in CMC/PAM/ZIF-67 hydrogel. According to the experimental, these enhancements synergistically enabled the CMC/PAM/ZIF-67 have a maximum adsorption capacity of 952 mg g−1. The adsorption process of CMC/PAM/ZIF-67 fits well with pseudo-second-order model and Langmuir isotherm. Meanwhile, the CMC/PAM/ZIF-67 maintain a high removal rate (87.3 %) and chemical stability even during ten adsorption-desorption cycles. It is worth noting that the adsorption amount of CMC/PAM/ZIF-67 in real seawater is 9.95 mg g−1 after 20 days, which is an ideal candidate adsorbent for uranium extraction from seawater. • The CMC/PAM/ZIF-67 aerogel is successfully designed via network-repairing strategy. • The CMC/PAM/ZIF-67 aerogel has a maximum adsorption capacity of 952 mg g−1 at pH = 5. • The adsorption capacity of CMC/PAM/ZIF-67 aerogel in real seawater is 9.95 mg g−1 after 20 days. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-adhesive, self-healing and multimodal sensing organohydrogel was prepared. • Environmental stability of organohydrogel is enhanced by glycerol and PA. • The organohydrogel shows wide humidity response and temperature detection range. • The organohydrogel displays reliable strain sensing ability in a wide strain range. Conductive hydrogel (CH) has drawn widespread interest in flexible electronics, human–computer interaction, and electronic skins (e-skins). However, it is challenging to integrate satisfactory self-adhesion, self-healing, environmental stability, and multi-stimulus response into a single CH system. Herein, a conductive nanocomposite organohydrogel with the above characteristics is well-designed and developed via incorporating carboxylic cellulose nanofibers-carrying carboxylic carbon nanotubes (C-CNTs) and phytic acid (PA) into polyacrylamide network through free-radical polymerization plus glycerol solvent displacement strategy, aiming for a high-performance multimodal sensing platform. Here, the coupling of C-CNTs and ionization of PA contributes a favorable conductivity, and the coexistence of glycerol and PA is beneficial for the formation of amounts of hydrogen bonds that endow the organohydrogel with outstanding stretchability, self-healing, and favorable adhesion in a wide temperature range of −30 to 60 °C. Besides, the resultant organohydrogel can effectively detect multiple external stimuli, manifesting high strain sensitivity over a broad strain range (0–1566 %), good humidity detectability at 0–85 % RH, and reliable thermosensation capability over a wide temperature window (−30 to 60 °C). Significantly, the application of the organohydrogel as e-skins are conducted to detect full-range human activity movements even in the extreme environments, identify hand gestures, and recognize the spatial distribution of humidity in noncontact sensing. All these indicate the preponderance of our organohydrogel in the fields of flexible smart electronics. [ABSTRACT FROM AUTHOR]

Nowadays, hydrogel-based sensors have drawn great attention owing to the growing demand for wearable devices. However, tailoring the property of the hydrogel sensor through a facile approach remains a great challenge. In this work, inspired by natural plants, a stretchable, adhesive and conductive hydrogel was prepared via the coordination between gallic acid (GA) and Zn2+ and chemical cross-linking. The dynamic crosslinking provided greater structural integrity for the polyvinyl alcohol / polyacrylamide (PVA/PAM) double network, endowing the hydrogel with high mechanical performance (0.25 MPa at 910% tensile strain, and 1.21 MPa at 70% compressive strain). Meanwhile, the presence of GA enabled the hydrogel with excellent repeatable adhesive performance, which greatly solved the problem of signal loss caused by poor adhesion. Moreover, the addition of ZnCl 2 enhanced the ionic conductivity and gauge factor of the hydrogel. Besides, the conductive hydrogel exhibited successively stable changes of resistance signals under different external stimuli (5–500% strains and 80–200 mm/min rates) and superior durability (over 500 cycles). The hydrogel-based wearable sensors demonstrated excellent sensing performance in detecting various human motions. The multifunctional PVA/PAM/GA-Zn2+ hydrogel has significant applications in soft robots and healthcare monitoring as the flexible strain sensor. [Display omitted] • The hydrogel was prepared via the coordination and chemical cross-linking. • The prepared hydrogel has excellent mechanical properties performance. • Plant-derived GA makes the hydrogels have good adhesion properties. • the hydrogel exhibited successively stable changes of resistance signals [ABSTRACT FROM AUTHOR]

In this study, a composite hydrogel with a low swelling ratio, excellent mechanical properties, and good U (VI) adsorption capacity was developed by incorporating a metal-organic framework (MOF) with a poly (acrylamide- co -acrylic acid)/chitosan (P(AM-co-AA)/CS) composite. The CS chain, which contains NH 2 , reduces the swelling ratio of the hydrogel to 4.17 after 5 h of immersion in water. The coordinate bond between the MOF and carboxyl group on the surface of P(AM-co-AA)/CS improves the mechanical properties and stability of P(AM-co-AA)/CS. The U(VI) adsorption capacity of P(AM-co-AA)/CS/MOF-808 is 159.56 mg g−1 at C 0 = 99.47 mg L−1 and pH = 8.0. The adsorption process is well fitted by the Langmuir isotherm and pseudo-second-order model. The P(AM-co-AA)/CS/MOF-808 also exhibits good repeatability and stability after five adsorption–desorption cycles. The uranium adsorption capacity of the developed adsorbent after one month in natural seawater is 6.2 mg g−1, and the rate of uranium adsorption on the hydrogel is 0.21 mg g−1 day−1. [Display omitted] [ABSTRACT FROM AUTHOR]

Micellar hydrogels formed by direct self-assembly of natural compounds have attracted widespread attention as delivery systems owing to their distinctive structures, excellent biocompatibility and simple preparation methods. Herein, we report on glycyrrhizic acid (GA), which is directly self-assembled into micellar hydrogels to encapsulate curcumin (Cur) through non-covalent interactions without excipients or structural modifications. Owing to their reversible non-covalent interactions, the micellar hydrogels have outstanding shear-thinning, self-healing ability and temperature-responsive behavior. Notably, the mechanical properties and release rates of the micellar hydrogels can be easily tuned by adjusting the concentration of GA. Furthermore, the GA@Cur micellar hydrogels have exhibited superior stability, remarkable biocompatibility and better antioxidant properties than free Cur, benefiting from improved solubility and stability. In brief, this micellar hydrogel inherits the advantages of both micelles and hydrogels: it has characteristics of micelles, naturally encapsulates Cur and has the ability of hydrogels to control long-term release. We believe this study will offer an innovative strategy to deliver Cur efficiently. [Display omitted] [ABSTRACT FROM AUTHOR]