Amoxicillin-laded sodium alginate/cellulose nanocrystals/polyvinyl alcohol composite nanonetwork sponges with enhanced wound healing and antibacterial performance.

Wound healing is a complex process and reuires a long repair process. Poor healing effect is normally a challenge for wound healing. Designing sponge dressings with drug-assisted therapy, good breathability, and multiple functional structures effectively promotes wound healing. In this work, a flexible amoxicillin-laded (AMX) sodium alginate (SA)/cellulose nanocrystals (CNCs)/ polyvinyl alcoho (PVA) (SA/CNCs/PVA-AMX, SCP-AMX) wound dressing was designed and built with an excellent porous structure, suitable porosity, and anti-bacterial properties for promoting wound tissue reparation. The porous structure of the wound dressing was fabricated by freeze-thawing cyclic and freeze-dried molding process. This wound dressing exhibited a 3D porous structure for soft-tissue-engineering application, including high porosity (84.2%), swelling ratio (1513%), tensile strength (1.79 MPA), and flexibility. With the inhibition zones of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) being 1.96 and4.58 cm, respectively, this wound dressing demonstrated good antibacterial activity against E. coli and S. aureus. More importantly, wound healing assay in vivo indicates that SCP-AMX could inhibit wound infection, promote collagen deposition, reduce inflammation, and accelerate granulation tissue and wound healing. Thus, the reported wounding dressings present excellent biocompatibility, high antibacterial activities, and excellent biosafety with great potential in wound healing applications.

Novel low-cost carboxymethyl cellulose microspheres with excellent fertilizer absorbency and release behavior for saline-alkali soil.

Saline-alkali soil and fertilizer loss severely restrict agriculture on the Songnen Plain in China. To resolve this problem, carboxymethyl cellulose immobilized slow-release fertilizer microspheres (CFM) with homogeneity pore structure, high porosity, biodegradable biological macromolecules and excellent fertilizer absorbency were synthesized by the combination of inverse emulsion polymerization and microfluidic method. By optimizing the synthesis conditions, the water absorption of CFM reached 8725 g g-1 in deionized water. The absorbency behaviors of CFM were highly sensitive to pH, ionic strength, and ionic species. In 5 g L-1 urea solution, the adsorption capacity of CFM was 3342.84 g g-1. The CFM showed excellent urea retention at 80 °C for 5 h and sustained release performance in soil. Besides, degradation rate of CFM was closed to 98.2% in Aspergillus niger at the third day. CFM had the advantages of high pH sensitivity, salt resistance, and good fertilizer absorbency and retention. Therefore, it will be prospecting fertilizer sustained release agent in agriculture.

Bio-templated 3D porous graphitic carbon nitride hybrid aerogel with enhanced charge carrier separation for efficient removal of hazardous organic pollutants.

Graphitic carbon nitride (g-C3N4) hybrid aerogels (GHAs) with different proportions of g-C3N4 were prepared using g-C3N4, carboxymethyl cellulose, and ß-cyclodextrin. GHAs have demonstrated high porosity, large specific surface area, rich three-dimensional network structure. GHAs demonstrated an excellent synergistic effect on the photocatalytic and adsorptive properties. Especially, GHA1 (the ratio of g-C3N4 and aerogel component was 1:1) exhibited a good synergy in photodegradation and adsorption, with a Rhodamine B (Rh B) removal up to 97.99% in 90 min. In five cycling experiments, the GHA1 showed a good long-term stability. The aerogels can be easily isolated and maintains its excellent photocatalytic properties. Compared to pure g-C3N4, GHA1 has a stronger photocurrent, which is due to the transmission of light to the surface of the catalyst, promoted photo-generated electron-hole pairs, and inhibited recombination of electros and holes. Finally, mechanistic studies reveal that the superoxide radicals (O2-) are the main active groups in the photocatalytic degradation process. This work provides a useful perspective in design and fabrication of hybrid aerogel composites with an enhanced photocatalytic activity.

Sodium alginate templated hydroxyapatite/calcium silicate composite adsorbents for efficient dye removal from polluted water.

In this work, natural polysaccharide product sodium alginate (SA) served as templates to prepare porous calcium silicate (CS) hydroxyapatite (HA) composite microspheres (CHCM) with high specific surface area by a new route combining ion exchange and calcination. CHCM played an important role in the fields of environmental protection with its large specific surface area, excellent adsorptive property, high mechanical strength and good regeneration performance. In order to explore its treatment capacity of wastewater, a series of eriochromeblue black R (EBBR) adsorption experiments were carried out. The equilibrium data fitted well with the Langmuir isotherm with a maximum adsorption capacity of 76.80 mg/g. Electrostatic interaction, ionic bonds and physical adsorption were responsible for the interactions between the EBBR and CHCM. Meanwhile, the CHCM maintained complete spherical and almost undamaged in the regeneration experiments, which confirmed its stability for cyclical usage. This paper demonstrates the role of natural polysaccharide product sodium alginate serving as templates to prepare useful products with potential wide applications.

N,S-self-doped carbon quantum dots from fungus fibers for sensing tetracyclines and for bioimaging cancer cells.

In this work, nitrogen and sulfur dual-doped carbon quantum dots (N,S-CDs) from naturally renewable biomaterial fungus fibers were prepared by a biosynthesis and hydrothermal method. The N,S-CDs displayed good water solubility, excellent stability, high quantum yield (QY = 28.11%) as well as remarkable features for fluorescence quenching-based detection and cellular imaging of cancer cells. It was worth mentioning that the heteroatoms doped carbon quantum dots made from the fungus fibers had a satisfactory QY and could be used as a selective, efficient, and sensitive fluorescent probe to determine tetracyclines by the synergistic effects of static quenching and internal filtration effect. The probe demonstrated a wide linear range and low detection limit. For tetracycline, the linear range was 0.5 µM to 47.6 µM, and the corresponding detection limit was 15.6 nM. Significantly, the test papers prepared by using N,S-CDs could detect tetracyclines in aquiculture wastewater rapidly. The produced N,S-CDs did not affect the cell viability and showed great promises for cellular imaging.