Sustainable Antibacterial and Anti-Inflammatory Silk Suture with Surface Modification of Combined-Therapy Drugs for Surgical Site Infection.

Silk sutures with antibacterial and anti-inflammatory functions were developed for sustained dual-drug delivery to prevent surgical site infections (SSIs). The silk sutures were prepared with core-shell structures braided from degummed silk filaments and then coated with a silk fibroin (SF) layer loaded with berberine (BB) and artemisinin (ART). Both the rapid release of drugs to prevent initial biofilm formation and the following sustained release to maintain effective concentrations for more than 42 days were demonstrated. In vitro assays using human fibroblasts (Hs 865.Sk) demonstrated cell proliferation on the materials, and hemolysis was 2.4 ± 0.8%, lower than that required by ISO 10993-4 standard. The sutures inhibited platelet adhesion and promoted collagen deposition and blood vessel formation. In vivo assessments using Sprague-Dawley (SD) rats indicated that the coating reduced the expression of pro-inflammatory cytokines interleukin-10 (IL-10) and tumor necrosis factor-α (TNF-α), shortening the inflammatory period and promoting angiogenesis. The results demonstrated that these new sutures exhibited stable structures, favorable biocompatibility, and sustainable antibacterial and anti-inflammatory functions with potential for surgical applications.

Characteristics of trace metals and phosphorus in seawaters offshore the Yangtze River.

This study presents the spatial distribution of total dissolved Cu, Zn, Co, and V during an autumn survey in the East China Sea (ECS). Dissolved Fe and its organic complexation were also investigated. The present study aimed to evaluate the relationship between Cu, Zn, Co, V, D-Fe and its organic ligands and total dissolved phosphate (TDP) in the coastal waters of the ECS. A correlation analysis shows that Cu, Zn and D-Fe were nutrient-like metals, whereas Co and V were non-nutrient-like metals. A multivariate statistical analysis showed that TDP was associated with D-Fe, Cu, Zn and Co, but was not associated with V. Furthermore, TDP was observed to be positively related with D-Fe, while negatively with Fe', which indicated that the limitation of TDP decreased the uptake of Fe'. This paper improves our understanding of the association among trace metals, TDP and phytoplankton biomass in the ECS.

[Elucidating the structure of two cyclotides of Viola tianshanica maxim by MALDI TOF/TOF MS analysis].

The cyclotides are a family of cyclic "mini" proteins that occur in Violaceae, Rubiaceae and Cucurbitaceae plant families and contain a head-to-tail cyclic backbone and a cystine knot arranged by three disulfide bonds. To study the natural cyclotides of V tianshanica, dried herb was extracted with 50% ethanol, and the concentrated aqueous extract was subjected to a solvent-solvent partitioning between water and hexane, ethyl acetate and n-butanol, separately. The n-butanol extract containing cyclotides was subjected to column chromatography over Sephadex LH-20, eluted with 30% methanol. The subfractions were directly reduced by DTT and analyzed by reverse-phase HPLC. The peaks with different retention times were shown on the profile of RP-HPLC and collected. The cyclotides were speculated based on masses range from 3 000 to 3 500 Da. The purified cyclotides were reduced with DTT, alkylated with iodoacetamide, and then were cleaved with endoproteinase Glu-C, endoproteinase Lys-C and Trypsin, separately. The digested peptides were purified on RP-HPLC and analyzed on MALDI TOF/TOF analyzer. A new cyclotide, cycloviolacin T1 and a reported cyclotide varv E were systemically determined using MALDI TOF/TOF system. So the method for the isolation and characterization of cyclotides was quickly built up in succession.