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With the popularisation of laparoscopic cholecystectomy, ligation clips have been commonly used for ligating the cystic duct and cystic artery. However, non-degradable clips remain in the body long-term, which significantly increases the risk of the clip becoming detached. Thus, magnesium alloys have attracted tremendous attention owing to their biodegradability and good biocompatibility. However, the poor corrosion resistance hinders the clinical application of magnesium alloys with microarc oxidation/phytic acid (MAO/PA) composite coatings as protective coatings. Here, these alloys were used to hinder the rapid material degradation in aqueous solution. Electrochemical tests were conducted to evaluate the in vivo degradation behaviour in simulated body fluid (SBF) for Mg–Zn–Y–Nd alloys, and scanning electron microscopy (SEM) was used to observe the micromorphology of in vivo clip degradation. Cell toxicity, cell adhesion, and flow cytometry were performed in vitro to detect cytocompatibility. Biochemical detection of serum magnesium, serum creatinine (CREA), blood urea nitrogen (BUN), alanine transaminase (ALT), and alanine aminotransferase (AST), and haematoxylin–eosin (HE) staining of the heart, liver, and kidney tissues in vivo was conducted to determine the biocompatibility properties after surgery. Electrochemical measurements and SEM images revealed that the MAO/PA-coated magnesium alloy delayed corrosion in SBF. The apoptosis rate increased slightly with increased extract concentration. Nevertheless, MAO/PA-coated magnesium alloys still exhibited good cytocompatibility. No obvious abnormality was observed in the blood biochemical test or HE staining. Thus, MAO/PA-coated magnesium alloys exhibit better corrosion than bare magnesium. In addition, Mg–Zn–Y–Nd and MAO/PA-coated magnesium alloys exhibited no cytotoxicity, good adhesion, and biosafety.

Background Aberrant hippocampal neurogenesis is an important pathological feature of sepsis-associated encephalopathy. In the current study, we examined the potential role of the long noncoding RNA (lncRNA) sex-determining region Y-box 2 (SOX2) overlapping transcript (SOX2OT), a known regulator of adult neurogenesis in sepsis-induced deficits in hippocampal neurogenesis and cognitive function. Methods Sepsis was induced in adult C57BL/6 J male mice by cecal ligation and perforation (CLP) surgery. Randomly selected CLP mice were transfected with short interfering RNAs (siRNAs) against SOX2OT or SOX2, or with scrambled control siRNA. Cognitive behavior was tested 8–12 days post-surgery using a Morris water maze. Western blotting and RT-qPCR were used to determine expression of SOX2, Ki67, doublecortin (DCX), nestin, brain lipid-binding protein, and glial fibrillary acidic protein (GFAP) in the hippocampus. The number of bromodeoxyuridine (BrdU)+/DCX+ cells, BrdU+/neuronal nuclei (NeuN)+ neurons, and BrdU+/GFAP+ glial cells in the dentate gyrus were assessed by immunofluorescence. Results CLP mice showed progressive increases in SOX2OT and SOX2 mRNA levels on days 3, 7, and 14 after CLP surgery, accompanied by impaired cognitive function. Sepsis led to decrease in all neuronal markers in the hippocampus, except GFAP. Immunofluorescence confirmed the decreased numbers of BrdU+/DCX+ cells and BrdU+/NeuN+ neurons, and increased numbers of BrdU+/GFAP+ cells. SOX2OT knockdown partially inhibited the effects of CLP on levels of SOX2 and neuronal markers, neuronal populations in the hippocampus, and cognitive function. SOX2 deficiency recapitulated the effects of SOX2OT knockdown. Conclusion SOX2OT knockdown improves sepsis-induced deficits in hippocampal neurogenesis and cognitive function by downregulating SOX2 in mice. Inhibiting SOX2OT/SOX2 signaling may be effective for treating or preventing neurodegeneration in sepsis-associated encephalopathy.

Objective To elucidate the neuroprotective function of metformin in suppressing propofol-induced apoptosis of HT-22 cells. Methods HT-22 cells were treated with 0, 10 or 100 μmol/L propofol, followed by determination of their proliferative ability. Subsequently, changes in proliferation and apoptosis of propofol-treated HT-22 cells induced with metformin were assessed. Apoptosis-associated genes in HT-22 cells were detected by Western blot. At last, regulatory effects of Cav-1 on propofol and metformin-treated HT-22 cells were examined. Results Propofol treatment dose-dependently decreased proliferative ability and increased apoptosis ability in HT-22 cells, which were partially blocked by metformin administration. Upregulated Bcl-2 and downregulated Bax were observed in propofol-treated HT-22 cells following metformin administration. In addition, Cav-1 level in HT-22 cells was regulated by metformin treatment. Notably, metformin reversed propofol-induced apoptosis stimulation and proliferation decline in HT-22 cells via downregulating Cav-1. Conclusion In our study, we found that propofol could induce apoptosis of HT-22 cells and metformin could rescue the apoptosis effect regulated by propofol. Then, we found that metformin protects propofol-induced neuronal apoptosis via downregulating Cav-1.

Differential scanning calorimetry was used to investigate the non-isothermal crystallization kinetics of the Fe76.5Nb3B20Cu0.5 glassy alloys. The nanocrystallization products and soft magnetic properties as a function of annealing temperatures were also studied by using X-ray diffractometer and vibrating sample magnetometer. The activation energies for Eg, Ex, and Ep are equal to 499 ± 3, 558 ± 7, and 693 ± 2 kJ mol−1 by Kissinger method, respectively, and 512 ± 3, 571 ± 9, and 715 ± 2 kJ mol−1 estimated by Ozawa method, respectively. The results indicate that the glass transition process is easier than the nucleation and grain growth process, while the grain growth process is much difficult than the nucleation process. The local Avrami exponent n(x) varies with the crystallized volume fraction x, indicating that the crystallization process has different crystallization mechanisms. The n(x) ranging from 1.0 to 1.2 for 0.05

Silica aerogel is one of the most attractive insulation materials but has not been broadly applied yet because of limitation of its fragile nature. In this work, we synthesized a compressible bacterial cellulose/silica aerogel composite from the co-precursor of tetraethylorthosilicate and methyltrimethoxylsilane by a two-step acid-base catalyzed sol-gel method followed by supercritical CO2 drying. This aerogel composite possessed a series of excellent properties: standing the considerable strain, high resilience, dust-free, low density of 0.066 g/cm3 and low thermal conductivity of 0.0292 W/(m·K) along with hydrophobicity with a water contact angle of 147°. Weight loss analysis indicated that the thermal stability of the as-prepared composites was about 270 °C which primarily depended on the thermal stability of the bacterial cellulose. These outstanding properties were attributed to the Interpenetration Polymer Network structure formed via the co-precursors and the bacterial cellulose and the excellent fabric of the aerogel retained by the supercritical CO2 drying. The results suggest that the as-prepared aerogel composite has potential applications as a suitable insulation material with dust-free and resilience.

Multi-arm star polyornithines PEI-P(Orn) n are prepared by grafting polyornithine arms onto branched polyethylenimine (PEI) with an M w of 600 via the ring-opening polymerization of N -carboxyanhydride of benzyloxycarbonyl ornithine. To enhance gene delivery efficiency and reduce cytotoxicity, the amino side groups on the polyornithine arms are partially guanidinated that transforms the ornithine units to arginine units. Thus, the guanidinated products G-PEI-P(Orn) n contain multiple poly(ornithine-co-arginine) arms. PEI-P(Orn) n and G-PEI-P(Orn) 71 mediate the transfection of pGL3 plasmid to 293T cells almost as efficient as 25 kDa PEI in serum-free medium. Notably, in contrast to the dramatically lowered efficiency of 25 kDa PEI in the presence of serum, the efficiency of G-PEI-P(Orn) 71 can be retained or even enhanced in the medium containing 10% serum. The improved serum-compatibility and high efficiency of the guanidinium-modified star polyornithines make them promising for gene delivery.

Phenylboronic acid-functionalized amphiphilic block copolymer Pluronic-PMCC-BA was synthesized via ring-opening polymerization of 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) with fumaric acid as a catalyst followed by the deprotection of carboxyl groups by catalyzed hydrogenation and the condensation of 3-aminophenylboronic acid with the copolymer side groups. Pluronic-PMCC-BA can form stable micelle solution by self-assembly in water. The phenylboronic acid groups are located at the shell of micelle as proved by (1)H NMR. The diameter of drug-free micelles is approximate 60 nm. Nano-spheres with narrow size distribution could be observed in the TEM image. MTT assay results show that Pluronic-PMCC-BA exhibits slight cytotoxicity when the polymer concentration is higher than 25 μg mL(-1). The toxicities of DOX@Pluronic-PMCC and DOX@Pluronic-PMCC-BA to COS7, HeLa, and HepG2 cell lines are similar with those of free DOX. Interestingly, phenylboronic acid groups located at the surface of Pluronic-PMCC-BA micelles can recognize HepG2 cells and promote the drug uptake of the cells, which are observed by confocal laser scanning microscopy (CLSM). The results imply that Pluronic-PMCC-BA would be a promising material for targeted drug delivery to the cancer cells.

A water-soluble polycarbonate with dimethylamino pendant groups, poly(2-dimethylaminotrimethylene carbonate) (PDMATC), is synthesized and characterized. First, the six-membered carbonate monomer, 2-dimethylaminotrimethylene carbonate (DMATC), is prepared via the cyclization reaction of 2-(dimethylamino)propane-1,3-diol with triphosgene in the presence of triethylamine. Although the attempted ring-opening polymerization (ROP) of DMATC with Sn(Oct)(2) as a catalyst fails, the ROP of DMATC is successfully carried out with Novozym-435 as a catalyst to give water-soluble aliphatic polycarbonate PDMATC with low cytotoxicity and good degradability.

A phenylboronic-acid-modified amphiphilic block polyether is prepared via reaction of polyglycidol-block-poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide)-block-polyglycidol (Pluronic-PG) with 2-(N,N-dimethylaminomethyl)-5-aminomethyl phenylboronic acid using phosgene as a coupling reagent. The boronic-acid-modified non-cationic polymer binds plasmid pGL3 effectively, forms sub-µm polymer/DNA complex particles, and greatly facilitates the cell uptake of the plasmid. The efficiency of the polymer as a gene vector is evaluated in vitro by transfection of pGL3 to HeLa, COS-7 and HepG2 cells. Pluronic-PG-BA enhances the transfection efficiency by 100 to 1000 times compared with Pluronic-PG. The presence of serum does not significantly affect the transfection efficiency.