Fluorescent Double Network Hydrogels with Ionic Responsiveness and High Mechanical Properties for Visual Detection

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.

Polyzwitterionic cross-linked double network hydrogel electrolyte enabling high-stable Zn anode

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 H_(2)O-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(H_(2)O)_(6)]^(2+)to R-SO_(3)^(−)[Zn(H_(2)O)_(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||MnO_(2)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.

Highly antifouling double network hydrogel based on poly(sulfobetaine methacrylate)and sodium alginate with great toughness

Hydrogels with good antifouling and mechanical properties as well as biocompatibility have great application potential in the field of biomedicine.In this paper,a newly double network(DN)hydrogel was prepared based on zwitterionic material sulfobetaine methacrylate(SBMA)and natural polysaccharide,sodium alginate(SA).The PSBMA network is covalently crosslinked while the SA network is ionically crosslinked by Ca^(2+).The hybrid crosslinked double network structure endows the DN hydrogel with excellent mechanical properties(E=0.19±0.01 MPa,σ=0.73±0.03 MPa),fast self-recovery ability as well as excellent fatigue resistance.Moreover,the results show that the PSBMA/SA-Ca^(2+)DN hydrogel is biocompatible and resists the absorption of non-specific proteins and adhesion of microorganisms,such as cells and algae,exhibiting outstanding antifouling properties.These unique characteristics of PSBMA/SA-Ca^(2+)DN hydrogel make it a promising candidate for biomedical application,such as artificial connective tissues,implantable devices,and underwater equipment.

Antifouling and antimicrobial cobaltocenium-containing metallopolymer double-network hydrogels

Compared with single-network hydrogels,double-network hydrogels offer higher mechanical strength and toughness.Integrating useful functions into double-network hydrogels can expand the portfolios of the hydrogels.We report the preparation of double-network metallopolymer hydrogels with remarkable hydration,antifouling,and antimicrobial properties.These cationic hydrogels are composed of a first network of cationic cobaltocenium polyelectrolytes and a second network of polyacrylamide,all prepared via radical polymerization.Antibiotics were further installed into the hydrogels via ion-complexation with metal cations.These hydrogels exhibited significantly enhanced hydration,compared with polyacrylamide-based hydrogels,while featuring robust mechanical strength.Cationic metallopolymer hydrogels exhibited strong antifouling against oppositely charged proteins.These antibiotic-loaded hydrogels demonstrated a synergistic effect on the inhibition of bacterial growth and antifouling of bacteria,as a result of the unique ion complexation of cobaltocenium cations.

A bioinspired and high-strengthed hydrogel for regeneration of perforated temporomandibular joint disc:Construction and pleiotropic immunomodulatory effects

Due to the lack of an ideal material for TMJ(temporomandibular joint)disc perforation and local inflammation interfering with tissue regeneration,a functional TGI/HA-CS(tilapia type I gelatin/hyaluronic acid-chondroitin sulfate)double network hydrogel was constructed in this paper.It was not only multiply bionic in its composition,structure and mechanical strength,but also endowed with the ability to immunomodulate microenvironment and simultaneously induce in situ repair of defected TMJ discs.On the one hand,it inhibited inflammatory effects of inflammasome in macrophages,reduced the extracellular matrix(ECM)-degrading enzymes secreted by chondrocytes,reversed the local inflammatory state,promoted the proliferation of TMJ disc cells and induced fibrochondrogenic differentiation of synovium-derived mesenchymal stem cells(SMSCs).On the other hand,it gave an impetus to repairing a relatively-large(6 mm-sized)defect in mini pigs’TMJ discs in a rapid and high-quality manner,which suggested a promising clinical application.