Yeast ß-glucan-based nanoparticles loading methotrexate promotes osteogenesis of hDPSCs and periodontal bone regeneration under the inflammatory microenvironment.

The regeneration of absorbed alveolar bone and reconstruction of periodontal support tissue are huge challenges in the clinical treatment of periodontitis due to the limited regenerative capacity of alveolar bone. It is essential to regulate inflammatory reaction and periodontal cell differentiation. Based on the anti-inflammatory effect of baker's yeast ß-glucan (BYG) with biosafety by targeting macrophages, the BYG-based nanoparticles loading methotrexate (cBPM) were fabricated from polyethylene glycol-grafted BYG through chemical crosslinking for treatment of periodontitis. In our findings, cBPM promoted osteogenesis of human dental pulp stem cells (hDPSCs) under inflammatory microenvironment, characterized by the enhanced expression of osteogenesis-related Runx2 and activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/Erk) pathway in vitro. Animal experiments further demonstrate that cBPM effectively promoted periodontal bone regeneration and achieved in a better effect of recovery indicated by 19.2 % increase in tissue volume, 7.1 % decrease in trabecular separation, and a significant increase in percent bone volume and trabecular thickness, compared with the model group. Additionally, cBPM inhibited inflammation and repaired alveolar bone by transforming macrophage phenotype from inflammatory M1 to anti-inflammatory M2. This work provides an alternative strategy for the clinical treatment of periodontitis through BYG-based delivery nanoplatform of anti-inflammatory drugs.

Inhibition of human cervical cancer development through p53-dependent pathways induced by the specified triple helical ß-glucan.

This study demonstrates that the purified ß-glucan (LNT) with a triple helix and relatively narrow molecular weight distribution, extracted and purified from artificially cultured Lentinus edodes, showed a significant cervical cancer inhibition with little cytotoxicity against normal cells in vitro and in vivo. From the in vitro data, the potential mechanism of anti-cervical cancer was preliminarily revealed as follows: LNT was firstly recognized by the human cervical cancer cell line of Hela and induced cell proliferation inhibition through p21 and apoptosis via a mitochondrion-dependent pathway by targeting the tumor suppressor of p53, indicated by an increase in reactive oxygen species (ROS) generation and a loss of mitochondrial membrane potential (Δψm), in a significant dosage-dependent manner. Meanwhile, LNT repressed tumor growth with an inhibition ratio of 61.2 % and induced tumor cell apoptosis through endogenous MDM2/p53/Bax/mitochondrion signal pathway by up-regulating the expression of p53, Bax, Cyt. c, caspase 9, and caspase 3, as well as down-regulating Bcl-2, MDM2, and PARP1 levels in Hela cells-transplanted BALB/c nude mice. This study provides a scientific basis for the clinical treatment of cervical cancer with LNT as a potential drug candidate characterized by the triple helix and specified molecular weight with a relatively narrow distribution.

Species-specific identification of Pseudomonas based on 16S-23S rRNA gene internal transcribed spacer (ITS) and its combined application with next-generation sequencing.

BACKGROUND: Pseudomonas species are widely distributed in the human body, animals, plants, soil, fresh water, seawater, etc. Pseudomonas aeruginosa is one of the main pathogens involved in nosocomial infections. It can cause endocarditis, empyema, meningitis, septicaemia and even death. However, the Pseudomonas classification system is currently inadequate and not well established. RESULTS: In this study, the whole genomes of 103 Pseudomonas strains belonging to 62 species available in GenBank were collected and the specificity of the 16S-23S ribosomal RNA internal transcribed spacer (ITS) sequence was analysed. Secondary structures of ITS transcripts determining where the diversity bases were located were predicted. The alignment results using BLAST indicated that the ITS sequence is specific for most species in the genus. The remaining species were identified by additional frequency analyses based on BLAST results. A double-blind experiment where 200 ITS sequences were randomly selected indicated that this method could identify Pseudomonas species with 100% sensitivity and specificity. In addition, we applied a universal primer to amplify the Pseudomonas ITS of DNA extracts from fish samples with next-generation sequencing. The ITS analysis results were utilized to species-specifically identify the proportion of Pseudomonas species in the samples. CONCLUSIONS: The present study developed a species-specific method identification and classification of Pseudomonas based on ITS sequences combined NGS. The method showed its potential application in other genera.

Single Molecular Chelation Dynamics Reveals That DNA Has a Stronger Affinity toward Lead(II) than Cadmium(II).

Lead ions can bind to DNA via nonelectrostatic interactions and hence alter its structure, which may be related to their adverse effects. The dynamics of Pb2+-DNA interaction has not been well understood. In this study, we report the monomolecular dynamics of the Pb2+-DNA interaction using a magnetic tweezers (MT) setup. We found that lead cations could induce DNA compaction at ionic strengths above 1 µM, which was also confirmed by morphology characterization. The chelation behavior of the Pb2+-DNA and the Cd2+-DNA complex solutions after adding EDTA were compared. The results showed that EDTA chelated with the bound metal ions on DNA and consequently led to restoring the DNA to its original length but with different restoration speeds for the two solutions. The fast binding dynamics and the slower chelation dynamics of the Pb2+ scenario compared to that of Cd2+ suggested that Pb2+ was more capable to induce DNA conformational change and that the Pb2+-DNA complex was more stable than the Cd2+-DNA complex. The stronger affinities for DNA bases and the inner binding of lead cations were two possible causes of the dynamics differences. Three agents, including EDTA, sodium gluconate, and SDBS, were used to remove the bound lead ions on DNA. It was shown that EDTA was the most efficient, and sodium gluconate could not fully restore DNA from its compact state. We concluded that both EDTA and SDBS were good candidates to restore the Pb2+-bound DNA to its original state.

Structure and pro-inflammatory activities of bran polysaccharides from a novel wheat kernel.

In this study, the structure and pro-inflammatory activities of water-soluble wheat bran polysaccharides (WBP) were evaluated. WBP were heteropolysaccharides consisting 60.34% arabinoxylan as the main component and 31.80% mannose residues characterized with the instrumental analyses. The result of cellular experiment displayed that WBP had significant pro-inflammatory activities by increasing the concentration of nitric oxide (NO) and up-regulating the inflammatory cytokine expressions of inducible nitric oxide synthase (iNOS), interleukin-1ß (IL-1ß), cyclooxygenase-2 (COX-2), and tumor necrosis factor-α (TNF-α). WBP mediated macrophages RAW 264.7 pro-inflammatory response through phosphatidylinositol 3 hydroxykinase/protein kinase B (PI3K/Akt) signaling pathway by significantly promoting Akt and phosphoinositide-dependent kinase 1 (PDK1) phosphorylations. Meanwhile, the expression of related phosphorylated proteins JNK and ERK1/2 was significantly up-regulated which suggested that WBP played pro-inflammatory roles by activating mitogen-activated protein kinases (MAPKs) signaling pathway. PRACTICAL APPLICATIONS: In recent years, wheat bran generally has the phenomenon of high yield and low utilization rate. Wheat bran has rich nutritional value and contains a lot of effective biologically active substances. Based on our findings, the water-soluble polysaccharides extracted from wheat bran have significant effects on regulating immunity and can be utilized as sources of natural immune modulators. The research can develop new functions of wheat bran polysaccharides, and improve processing utilization rate and product added value.

Characterization and antibacterial properties of epsilon-poly- l-lysine grafted multi-functional cellulose beads.

In recent years, harmful microorganisms in water pose great harm to ecological environment and human health. To solve this problem, epsilon-poly-l-lysine (EPL) grafted cellulose beads were prepared via 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) mediated oxidation and carbodiimide mediated cross-linking reaction. Hydroxyl groups on C6 of cellulose were oxidized to carboxyl groups by TEMPO and grafting reaction was achieved between newly formed carboxyl groups of cellulose and amino of EPL. The beads were characterized by FTIR, SEM, XRD and TGA. The crystalline form of cellulose transformed from cellulose I to cellulose II after being dissolved and regenerated. The grafted cellulose beads showed good antibacterial activities against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and Alicyclobacillus acidoterrestris with 10 h. The beads could be biodegraded in soil after 28 days. It is expected that the bio-based composite beads could have potential applications in water purification and food treatment fields.

Fabrication and characterization of antibacterial epsilon-poly-L-lysine anchored dicarboxyl cellulose beads.

Pathogens in the food and environment pose a great threat to human health. To solve this problem, we described a novel route to synthesize antibacterial epsilon-poly-L-lysine (EPL) anchored dicarboxyl cellulose beads. Cellulose beads were prepared via a sol-gel transition method and oxidized by sodium periodate and sodium chlorite to form carboxyl groups. EPL was anchored on the beads using carbodiimide mediated amidation. The structure and morphology of beads were characterized by FTIR, XPS, XRD, SEM, and TGA. After dissolution and regeneration, the crystalline form of cellulose is transformed from cellulose I to cellulose II. The thermal degradation temperature of the beads is 200∼300 °C.The samples displayed excellent antimicrobial activity against Staphylococcus aureus, Alicyclobacillus acidoterrestris and Escherichia coli within 12 h. The beads could be biodegraded in soil after 20 days. The biodegradable beads exhibited great potential in food and environmental applications.

Construction and structure-activity mechanism of polysaccharide nano-selenium carrier.

In this study, a series water soluble sulfate polysaccharides (SPS) with different degrees of substitutions (DS = 0.02∼0.28) were prepared using a linear water-insoluble ß-d-(1→3)-glucan. SPS-1, SPS-3 and SPS-7 with substitution degrees of 0.02, 0.06 and 0.25 were used as templates to prepare stable and size controlled selenium nanoparticles (SeNPs) with diameter from 54.35 to 123.04 nm using one-step method. The selenium contents of SPS-SeNPs with large, medium and small sizes were 0.172 %, 0.274 % and 0.305 %, respectively. SPS-SeNPs was confirmed to inhibit the production of nitric oxide (NO) in RAW 264.7 inflammatory macrophages induced by lipopolysaccharide (LPS), and downregulated the mRNA expression of TNF-α, IL-1ß and iNOS. The results indicated that SPS-SeNPs had significant anti-inflammatory activity. Moreover, SPS-SeNPs with smaller size showed higher anti-inflammatory effects. All of these results suggest that SeNPs-SPS carriers have anti-inflammatory in concentration-dependent and size-dependent model.

Characterization and antibacterial effect of quaternized chitosan anchored cellulose beads.

Some thermoduric food spoilage bacteria pose great threat to beverage industry. To tackle the challenge, hydroxypropyl trimethyl ammonium chloride chitosan (HTCC) grafted magnetic cellulose beads have been prepared via a dropping technology. Sodium periodate oxidation process was carried out to form dialdehyde functional groups on the regenerated cellulose beads mixed with maghemite nanoparticles. HTCC was anchored on the beads through Schiff base reaction. The structure and properties of HTCC anchored beads were evaluated by Fourier transform infrared (FTIR) spectra, field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). Thermal stability of the beads was estimated by thermogravimetric analysis (TGA) and differential thermal gravity (DTG), and the decomposition temperature of the beads were around 200-300 °C. A long-term antibacterial activities of the beads against Alicyclobacillus acidoterrestris were confirmed caused by the covalent bond between HTCC and the beads. The biodegradable HTCC grafted cellulose beads may provide a novel approach for food safety management.