Tunicate cellulose nanocrystals strengthened injectable stretchable hydrogel as multi-responsive enhanced antibacterial wound dressing for promoting diabetic wound healing.

The intricate microenvironment of diabetic wounds characterized by hyperglycemia, intense oxidative stress, persistent bacterial infection and complex pH fluctuations hinders the healing process. Herein, an injectable multifunctional hydrogel (QPT) was developed, which exhibited excellent mechanical performance and triple responsiveness to pH, temperature, and glucose due to dynamic covalent cross-linking involving dynamic Schiff base bonds and phenylboronate esters with phenylboronic-modified quaternized chitosan (QCS-PBA), polydopamine coated tunicate cellulose crystals (PDA@TCNCs) and polyvinyl alcohol (PVA). Furthermore, the hydrogels can incorporate insulin (INS) drugs to adapt to the complex and variable wound environment in diabetic patients for on-demand drug release that promote diabetic wound healing.

Tunicate cellulose nanocrystal reinforced multifunctional hydrogel with super flexible, fatigue resistant, antifouling and self-adhesive capability for effective wound healing.

Hydrogels as skin wound dressings have been extensively studied owing to their good flexibility and biocompatibility. Nevertheless, the mechanical performance, adhesive capability, antifouling and antibacterial properties of conventional hydrogels are still unsatisfactory, which hinder the application of hydrogel for cutaneous healing. Here, we developed a novel biocompatible multifunctional hydrogel with super flexible, fatigue resistant, antifouling and self-adhesive capability for effective wound healing, where naturally rigid polymers including quaternized chitosan (QCS) and Tunicate cellulose nanocrystals (TCNCs) are used as bioactive cross-linkers and reinforcers to endow the hydrogel with excellent mechanical and antibacterial property, and the synergistic contributions from the poly(acrylic acid/methacrylate anhydride dopamine/sulfobetaine methacrylate) (poly(AA/DMA/SBMA)) chains and QCS endow the hydrogel with excellent adhesive property, antioxidant, antifouling and pH-responsive sustained drug release capabilities.

Injectable, self-healable and antibacterial multi-responsive tunicate cellulose nanocrystals strengthened supramolecular hydrogels for wound dressings.

Wound dressing with an improved structural and functional recapitulation of damaged organs, efficient self-healing and antibacterial properties that can well integrate with tissue are urgently needed in wound management. Supramolecular hydrogels confer control over structural properties in a reversible, dynamic and biomimetic fashion. Herein, a kind of injectable, self-healing and antibacterial supramolecular hydrogel with multi-responses were fabricated by mixing phenylazo-terminated Pluronic F127, quaternized chitosan-graft-cyclodextrin and polydopamine coated tunicate cellulose nanocrystals under physiological conditions.

Dynamic Cross-Linking Network Construction of Carboxymethyl Starch Enabling Temperature and Strain Bimodal Film Sensors.

Building stimulus-responsive units in the hydrogel coatings remains challenging for film sensors consisting of alternated layers of inert substrates and hydrogel coatings. An interesting film sensor with a carboxymethyl starch-based hydrogel coating was developed here. The cross-linking networks of carboxymethyl starch play the roles of structure-constructing units and stimulus-controlling units simultaneously, endowing the coatings with thermal sensing and strain sensing capabilities.

Modified magnetic chitosan materials for heavy metal adsorption: a review.

Magnetic chitosan materials have the characteristics of both chitosan and magnetic particle nuclei, showing the characteristics of easy separation and recovery, strong adsorption capacity and high mechanical strength, and have received extensive attention in adsorption, especially in the treatment of heavy metal ions. In order to further improve its performance, many studies have modified magnetic chitosan materials. This review discusses the strategies for the preparation of magnetic chitosan using coprecipitation, crosslinking, and other methods in detail.

Multiply cross-linked poly(vinyl alcohol)/cellulose nanofiber composite ionic conductive hydrogels for strain sensors.

Building multiple chemical crosslinks is an effective strategy to improve mechanical properties and to diversify final application of polysaccharide nanoparticles reinforced poly(vinyl alcohol) (PVA) physical hydrogels. In this work, PVA/cellulose nanofibers (CNFs) were used as composite substrate to fabricate ionic conductive hydrogels for strain sensor. Three types of characteristic crosslinks, including chemical crosslinking via boronic ester covalent bonds only, and with additional metal coordination bonding, as well as coexistence of physical crosslinks via PVA crystallites and aforementioned two kinds of chemical crosslinks, were constructed.

Synthesis and visible-light photocatalytic degradation of AgPO/AgBr/hydroxyapatite ternary nanocomposites prepared from oyster shells.

In this paper, a new type of AgPO/AgBr/hydroxyapatite (HAP) composite was successfully prepared from oyster shells and silver nitrate by a hydrothermal method. The samples were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, electron spin resonance and other precision instruments, and their catalytic activity was characterized by visible light degradation of methylene blue (MB). The experimental results show that the AgPO/AgBr/HAP photocatalyst has a nanoscale rod-like structure and excellent photodegradation performance.

A facile method to fabricate thermo- and pH-sensitive hydrogels with good mechanical performance based on poly(ethylene glycol) methyl ether methacrylate and acrylic acid as a potential drug carriers.

A thermo- and pH-sensitive hydrogel was prepared by a facile free aqueous radical copolymerization of PEGMA and AAc without any crosslinkers for controlled drug delivery. The successful fabrication of hydrogels was confirmed by Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) measurements. The morphological, mechanical and swelling properties of the obtained hydrogels were studied systematically.

Hydrazinolyzed cellulose-g-polymethyl acrylate as adsorbent for efficient removal of Cd(II) and Pb(II) ions from aqueous solution.

Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ), an efficient adsorbent for removal of Cd(II) and Pb(II) from aqueous solution, has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis. The influences of initial pH, contact time, and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were examined in detail. As for Cd(II) adsorption, kinetic adsorption can be explained by pseudo-second-order, while adsorption isotherm fits well with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 235.

Novel complex gel beads composed of hydrolyzed polyacrylamide and chitosan: an effective adsorbent for the removal of heavy metal from aqueous solution.

A novel kind of complex gel beads containing HPAM (hydrolyzed polyacrylamide) and chitosan components (HPAM-chitosan gel beads) was prepared and applied in the removal of Cu(2+), Pb(2+), and Hg(2+) ions from aqueous solutions. These gel beads exhibited a good performance for heavy metal removal. Moreover, the average diameter of these gel beads was about 1mm, which could be appropriate for use in column system.