Vegetable Oil-Based Waterborne Polyurethane as Eco-Binders for Sulfur Cathodes in Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) suffer from well-known fast capacity losses despite their extremely high theoretical capacity and energy density. These losses are caused by dissolution of lithium polysulfide (LiPS) in ether-based electrolytes and have become the main bottleneck to widespread applications of LSBs. Therefore, there is a significant need for electrode materials that have a strong adsorption capacity for LiPS. Herein, a waterborne polyurethane (WPUN) containing sulfamic acid (NH2 SO3 H) polymer is designed and synthesized as an aqueous-based, ecofriendly binder by neutralizing sulfamic acid with a tung oil-based polyurethane prepolymer. UV-vis spectroscopy shows that the WPUN strongly immobilizes LiPS and thus is an effective inhibitor of the LiPS. Moreover, the WPUN binder has excellent adhesive and mechanical properties that improve the integrity of sulfur cathodes. The WPUN-based cathodes exhibit a significant improvement in their specific capacity and maintain a capacity of 617 mAh g-1 after 200 cycles at 0.5C. Besides, the LSBs assembled with the WPUN-based cathodes show good rate performance from 0.2C (737 mAh g-1 ) to 4C (586 mAh g-1 ), which is significantly higher than that of LSBs assembled with a commercial polymer binder. The structural design of the presented binder provides a new perspective for obtaining high-performance LSBs.

A microtitre chemiluminescence sensor for detection of pyrethroids based on dual-dummy-template molecularly imprinted polymer and computational simulation.

The residues of pyrethroids in foods of animal origin are dangerous to the consumers, so this study presented a chemiluminescence sensor for determination of pyrethroids in chicken samples. A dual-dummy-template molecularly imprinted polymer capable of recognizing 10 pyrethroids was synthesized. The results of computation simulation showed that the specific 3D conformations of the templates had important influences on the polymer' recognition ability. The polymer was used to prepare a sensor on conventional 96-well microplates, and the sample solution was added into the wells for direct absorption. The absorbed analytes were initiated with the bis(2,4,6-trichlorophenyl)oxalate-H2 O2 -imidazole system, and the chemiluminescence intensity was used for analyte quantification. Results showed that one assay was finished within 12 min, and this sensor could be reused four times. The limits of detection for the 10 analytes were in the range o0.3-6.0 pg/ml, and the recoveries from the standards of fortified blank chicken samples were in the range 70.5-99.7%.

Determination of sulfonamides in meat with dummy-template molecularly imprinted polymer-based chemiluminescence sensor.

In this study, a molecularly imprinted polymer capable of recognizing 15 sulfonamides was first synthesized with sulfabenz as the dummy template. The calculation results from computation simulation showed that the specific 3D conformation of the template had an important influence on the polymer's recognition ability. Then, the polymer was used as recognition reagent to prepare a chemiluminescence sensor on a conventional 96-well microplate for the determination of the residues of 15 sulfonamides in meat (chicken and pork). Due to the 4-(imidazol-1-yl)phenol-enhanced luminol-H2O2 system, the limits of detection for the 15 analytes were in the range of 1.0-12 pg/mL. The recoveries from the standard fortified blank samples were in the range of 72.7-99%. Furthermore, one assay could be finished within 30 min, and the sensor could be reused 4 times. Therefore, this sensor could be used as a very useful tool for routine screening of residues of sulfonamides in meat samples. Graphical abstract Assay procedures of the molecularly imprinted polymer-based chemiluminescence sensor for determination of sulfonamides.

Mitochondrial oxidative stress alters a pathway in Caenorhabditis elegans strongly resembling that of bile acid biosynthesis and secretion in vertebrates.

Mammalian bile acids (BAs) are oxidized metabolites of cholesterol whose amphiphilic properties serve in lipid and cholesterol uptake. BAs also act as hormone-like substances that regulate metabolism. The Caenorhabditis elegans clk-1 mutants sustain elevated mitochondrial oxidative stress and display a slow defecation phenotype that is sensitive to the level of dietary cholesterol. We found that: 1) The defecation phenotype of clk-1 mutants is suppressed by mutations in tat-2 identified in a previous unbiased screen for suppressors of clk-1. TAT-2 is homologous to ATP8B1, a flippase required for normal BA secretion in mammals. 2) The phenotype is suppressed by cholestyramine, a resin that binds BAs. 3) The phenotype is suppressed by the knock-down of C. elegans homologues of BA-biosynthetic enzymes. 4) The phenotype is enhanced by treatment with BAs. 5) Lipid extracts from C. elegans contain an activity that mimics the effect of BAs on clk-1, and the activity is more abundant in clk-1 extracts. 6) clk-1 and clk-1;tat-2 double mutants show altered cholesterol content. 7) The clk-1 phenotype is enhanced by high dietary cholesterol and this requires TAT-2. 8) Suppression of clk-1 by tat-2 is rescued by BAs, and this requires dietary cholesterol. 9) The clk-1 phenotype, including the level of activity in lipid extracts, is suppressed by antioxidants and enhanced by depletion of mitochondrial superoxide dismutases. These observations suggest that C. elegans synthesizes and secretes molecules with properties and functions resembling those of BAs. These molecules act in cholesterol uptake, and their level of synthesis is up-regulated by mitochondrial oxidative stress. Future investigations should reveal whether these molecules are in fact BAs, which would suggest the unexplored possibility that the elevated oxidative stress that characterizes the metabolic syndrome might participate in disease processes by affecting the regulation of metabolism by BAs.

Hierarchical porous MOF-199 mediated cellulosic paper for selective CO2 capture.

MOF-199 is considered to be an excellent CO2 adsorbent owing to its substantial specific surface area, suitable pore structure and abundant sorption sites. However, powdered MOF-199 is prone to agglomeration and has poor recyclability. Herein, we proposed a MOF-199-based adsorbent by combining the MOF synthesis process with traditional papermaking process. Through such a design, MOF-199 particles are adhered on the surface of wood pulp fiber. The sufficient hydroxyl groups and electrostatic forces of cellulose facilitates the homogeneous and tight adhesion of MOF crystals. The optimal MP-4 sample demonstrated a high CO2 adsorption capacity (1.80 mmol·g--1 at 25 °C) and good CO2/N2 selectivity (30.06). Moreover, the composite sorbent can be easily regenerated. The adsorption mechanism was analyzed by the density functional theory approach. The simulation results showed that the carboxyl functional groups with a large number of oxygen atoms and active metal sites are the key to boost the CO2 adsorption performance.

Organic-inorganic composite hydrogels: compositions, properties, and applications in regenerative medicine.

Hydrogels, formed from crosslinked hydrophilic macromolecules, provide a three-dimensional microenvironment that mimics the extracellular matrix. They served as scaffold materials in regenerative medicine with an ever-growing demand. However, hydrogels composed of only organic components may not fully meet the performance and functionalization requirements for various tissue defects. Composite hydrogels, containing inorganic components, have attracted tremendous attention due to their unique compositions and properties. Rigid inorganic particles, rods, fibers, etc., can form organic-inorganic composite hydrogels through physical interaction and chemical bonding with polymer chains, which can not only adjust strength and modulus, but also act as carriers of bioactive components, enhancing the properties and biological functions of the composite hydrogels. Notably, incorporating environmental or stimulus-responsive inorganic particles imparts smartness to hydrogels, hence providing a flexible diagnostic platform for in vitro cell culture and in vivo tissue regeneration. In this review, we discuss and compare a set of materials currently used for developing organic-inorganic composite hydrogels, including the modification strategies for organic and inorganic components and their unique contributions to regenerative medicine. Specific emphasis is placed on the interactions between the organic or inorganic components and the biological functions introduced by the inorganic components. The advantages of these composite hydrogels indicate their potential to offer adaptable and intelligent therapeutic solutions for diverse tissue repair demands within the realm of regenerative medicine.

Rapid screening and determination of 4-chloroamphetamine in saliva by paper spray-mass spectrometry and capillary electrophoresis-mass spectrometry.

A novel drug-screening system, consisting of paper spray-MS (PS-MS) and a CE-ESI-MS method was developed. This system can be easily switched either to PS-MS for rapidly screening samples or to the traditional CE-ESI-MS method for separation and to obtain detailed mass spectral information, while sharing the same mass spectrometer. In the former case, when a sharp (15°-tip) chromatography paper was used, the optimized distance from the paper tip to the mass inlet was 7.7 mm, whereas the optimized distance for the CE-ESI tip was ∼13.5 mm. Using 4-chloroamphetamine as a model compound, the LODs for PS-MS and CE-ESI-MS were determined to ∼0.1 and 0.25 ppm, respectively. Comparisons of results obtained using PS-MS and CE-ESI-MS and the experimental conditions are described.

Rapid screening and determination of designer drugs in saliva by a nib-assisted paper spray-mass spectrometry and separation technique.

A method for the rapid screening and determination of amphetamine-type designer drugs in saliva by a novel nib-assisted paper spray-mass spectrometry procedure is described. Under optimized conditions, the limit of detections for amphetamine derivatives (model samples: o-, m-, p-chloroamphetamine and o-, m-, p-fluoroamphetamine, respectively) were determined to 0.1 µg/mL by the nib-assisted paper spray-mass spectrometry method. This method is easier and has a higher sensitivity than similar methodologies, including atmospheric pressure/matrix-assisted laser desorption ionization mass spectrometry and electrospray-assisted laser desorption ionization/mass spectrometry. Data obtained using more classical separation methods, including liquid chromatography and capillary electrophoresis, are also reported.

Synthesis of zwitterionic polymer modified graphene oxide for hydrophilic enrichment of N-glycopeptides from urine of healthy subjects and patients with lung adenocarcinoma.

As one of the most common and important post-translational modifications, protein N-glycosylation plays essential roles in many biological processes and have long been considered closely correlated with the occurrence and progression of multiple diseases. Systematic characterization of these disease-related protein N-glycosylation is one of the most convenient ways for new diagnostic biomarker and therapeutic drug target discovering. However, the biological samples are extremely complex and the abundance of N-glycoproteins are especially low, which make highly efficient N-glycoprotein/glycopeptide enrichment before mass spectrometry analysis a prerequisite. In this work, a new type of hydrophilic material (GO-pDMAPS) was prepared by in situ growth of linear zwitterionic polymer chains on the surface of GO and it was successfully applied for N-glycopeptide enrichment from human urine. Due to the excellent hydrophilicity and the facilitate interactions between this GO-pDMAPS and the targets, a total of 1426 N-glycosylated sites corresponding to 766 N-glycoproteins as well as 790 N-glycosylation sites corresponding to 470 N-glycoproteins were enriched and identified from urine of healthy subjects and patients with lung adenocarcinoma, respectively. Among which, 27 N-glycoproteins were expressed exclusively and 4 N-glycoproteins were upregulated at least 3 times comparing with the healthy group, demonstrating the tremendous potential of this new hydrophilic material for large scale and in depth N-glycoproteome research.

Construction of Gambogic Acid HPMA Copolymer Coupling Drug System and Study on Anti-tumor Activity.

AIM: An active-passive dual-targeting gambogic acid HPMA Copolymer Coupling drug system with high efficiency, low toxicity and high selectivity was constructed. METHODS: The gambogic acid HPMA copolymer coupling drug system was constructed and its structure was characterized. The cytotoxicity of gambogic acid HPMA copolymer was detected by MTT assay. The pharmacokinetics of gambogic acid HPMA copolymer was evaluated in mice. Targetability of gambogic acid HPMA copolymer was evaluated by tissue distribution experiment. The in vitro antitumor activity of gambogic acid HPMA copolymer was evaluated by pharmacodynamics experiment in mice. RESULTS: Two copolymers of gambogic acid HPMA were successfully prepared. The copolymers showed reduced cytotoxicity and a certain sustained release effect and targeting property. In vivo pharmacodynamic experiments also showed better anti-tumor effects than GA. DISCUSSION: In this study, gambogic acid was combined with HPMA polymer and the targeting molecule D-galactose/folic acid to form a polymer micelle with high efficiency, low toxicity and high selectivity for active-passive dual targeting. The construction of the drug system provides new ideas for future formulation research and development.

Study on the Slow-Release Mometasone Furoate Injection of PLGA for the Treatment of Knee Arthritis.

PURPOSE: The purpose of this study is to develop a new PLGA based formulation for microspheres, which aims to release mometasone furoate for one month, so as to improve compliance. METHODS: The microspheres containing mometasone furoate were prepared by oil in water emulsion and solvent evaporation. The microspheres were characterized by surface morphology, shape, size and encapsulation efficiency. The release in vitro was studied in 37°C phosphate buffer, and in vivo, pharmacodynamics and preliminary safety evaluation were conducted in male Sprague Dawley rats. RESULTS: The morphology results showed that the microspheres have a smooth surface, spherical shape and an average diameter of 2.320-5.679µm. The encapsulation efficiency of the microspheres loaded with mometasone furoate was in the range of 53.1% to 95.2%, and the encapsulation efficiency of the microspheres could be greatly affected by the proportion of oil phase to the water phase and other formulation parameters. In vitro release kinetics revealed that drug release from microspheres was through non-Fick's diffusion and PLGA polymer erosion. Pharmacokinetic data showed that the initial release of microspheres was small and then sustained. The results of the pharmacodynamics study fully proved the long-term effectiveness of mometasone furoate microspheres. The results of in vivo safety evaluation showed that the preparation system possessed good in vivo safety. CONCLUSION: This study shows that the microspheres prepared in this study have sufficient ability to stable drug release at least for 35 days, with good efficacy and high safety. In addition, mometasone furoate can be used as a potential candidate drug for 35 days long-term injection.

Polarization of tumor-associated macrophage phenotype via porous hollow iron nanoparticles for tumor immunotherapy in vivo.

Tumor-associated macrophages (TAMs) are the most important components in the tumor immunosuppressive microenvironment, promoting tumor growth and metastasis. Although TAMs have become one of the hot topics of tumor immunotherapy, challenges still remain to achieve TAM-targeted re-polarization therapy. In this work, porous hollow iron oxide nanoparticles (PHNPs) were synthesized for loading a P13K γ small molecule inhibitor (3-methyladenine, 3-MA) and further modified by mannose to target TAMs. The delivery system named PHNPs@DPA-S-S-BSA-MA@3-MA showed good efficiency for targeting TAMs. The inflammatory factor NF-κB p65 of macrophages was activated by the combination of PHNPs and 3-MA, which synergistically switched TAMs to pro-inflammatory M1-type macrophages. As a result, it activated immune responses and inhibited tumor growth in vivo. The study provides an intracellular switch of the TAM phenotype for targeted TAM therapy.

Detection of chloramphenicol in chicken, pork and fish with a molecularly imprinted polymer-based microtiter chemiluminescence method.

In this study, 4-nitrotoluene (NT) was used as dummy template to synthesize a molecularly imprinted polymer that was highly specific for chloramphenicol. The polymer was coated in the wells of 96-well microplates as recognition reagent to develop a chemiluminescence method. The analyte solution and an enzyme-labelled hapten were added into the wells to perform competition, and the light signal was induced with a highly efficient luminol-H2O2-4-(imidazol-1-yl)phenol system. Then, the optimized method was used to determine chloramphenicol in meat (chicken, pork and fish), and the limit of detection (LOD) was 5.0 pg g-1. Furthermore, the polymer-coated plate could be reused four times, and one test could be finished within 20 min. The recoveries from the standard fortified blank meat samples were in the range of 71.5-94.4%. Therefore, this method could be used as a useful tool for routine screening the residue of chloramphenicol in meat samples.

Dummy molecularly imprinted polymer based microplate chemiluminescence sensor for one-step detection of Sudan dyes in egg.

The objective of this study is to report a molecularly imprinted polymer-based chemiluminescence method for determination of Sudan dyes. A dummy-template molecularly imprinted polymer capable of recognizing seven Sudan dyes was first synthesized and its recognition mechanism was studied by using computation simulation method. The polymer was coated in the wells of conventional microplate to prepare a chemiluminescence sensor and the assay process consisted of only one sample-loading step prior to signal acquisition. The optimized sensor was used to determine the seven dyes in egg yolk and the results were confirmed with a high performance liquid chromatography. Results showed that this sensor achieved ultrahigh sensitivity (1.0-5.0 pg/mL), rapid assay process (10 min) and satisfactory recovery (70.5%-92.2%). Furthermore, the sensor could be reused for 5 times. Therefore, this sensor could be used as a useful tool for screening the residues of Sudan dyes in egg.

Biocompatible MoS2/PDA-RGD coating on titanium implant with antibacterial property via intrinsic ROS-independent oxidative stress and NIR irradiation.

To inhibit bacterial infection in situ and improve osseointegration are essentially important for long-term survival of an orthopedic implant, in particular for infection-associating revision surgery. Herein, we fabricate a functional molybdenum disulfide (MoS2)/polydopamine (PDA)-arginine-glycine-aspartic acid (RGD) coating on titanium (Ti) implant to address above concerns simultaneously. The coating not only improved the osteogenesis of mesenchymal stem cells (MSCs), but also endowed Ti substrates with effective antibacterial ability when exposing to near-infrared (NIR) irradiation. It accelerated glutathione (GSH) oxidation via photothermal energy and induced intrinsic ROS-independent oxidative stress damage deriving from MoS2 nanosheets. The results displayed that RGD-decorated MoS2 nanosheets significantly increased the cellular osteogenic behaviors of MSCs via up-regulating osteogenesis-related genes (ALP, Runx2, Col I and OCN) in vitro. Moreover, the functionalized Ti substrates demonstrated great antibacterial efficiency of over 92.6% inhibition for S. aureus and E. coli under NIR-irradiation. Hyperthermia induced by photothermal effect accelerated the GSH consumption and ROS-independent oxidative stress destroyed the integrity of bacteria membranes, which synergistically led to protein leakage and ATP decrease. Furthermore, co-culture experiment showed that S. aureus contamination was efficiently cleaned from MoS2/PDA-RGD surface after NIR photothermal treatment, while MSCs adhered and proliferated on the MoS2/PDA-RGD surface. In an S. aureus infection model in vivo, MoS2/PDA-RGD modified Ti rods killed bacteria with an efficiency of 94.6% under NIR irradiation, without causing damage to normal tissue. More importantly, the MoS2/PDA-RGD modified Ti implants accelerated new bone formation in comparison with TNT implants in vivo.

The fabrication and in vitro properties of antibacterial polydopamine-LL-37-POPC coatings on micro-arc oxidized titanium.

Bacterial infection commonly occurs in clinical settings when the procedure involves a medical implant. Thus, the fabrication of antimicrobial medical materials has attracted much attention in recent years. To improve the antibacterial properties of titanium (Ti)-based biomedical materials, surface microporous structures, with antimicrobial peptide coatings, were employed in this study. Native Ti substrates were endowed with a certain level of antibacterial activity after treatment with the micro-arc oxidation (MAO). A multilayer consisting of polydopamine, cationic antimicrobial peptides LL-37, and phospholipid (POPC) was coated onto MAO substrates, leading to antibacterial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. The combination of polydopamine-LL-37-POPC was found to alleviate the burst release of LL-37 in the initial phase. This multilayer coated onto microporous Ti substrates also showed favorable cytocompatibility to both mesenchymal stem cells (MSCs) and osteoblasts. These findings illustrate a novel strategy for the development of antibacterial Ti-based implants.

Preparing and immobilizing antimicrobial osteogenic growth peptide on titanium substrate surface.

The inherent bioinertness and potential bacterial infection risk are the two leading causes for Ti implant failure. To improve osseointegration and antibiosis, in this work, a novel antimicrobial osteogenic growth peptide was first synthesized by conjugating osteogenic growth peptide (OGP) and ciprofloxacin (CIP). Then, the synthetic antimicrobial peptide was immobilized onto Ti implant surface for chemoselective binding via the amide reaction. Thereafter, the capabilities of modified Ti implant on osseointegration and antibiosis were measured with cell experiments and antimicrobial activity in vitro. The results showed that antimicrobial osteogenic growth peptide (OGP-CIP) was successfully prepared and grafted onto Ti implant surface. Moreover, the antimicrobial peptide-modified Ti implants could promote osteoblasts spreading and osteodifferentiation compared with unmodified Ti substrates. Meanwhile, in vitro bacteria studies (Staphylococcus aureus and Escherichia coli) proved that the antibacterial property of antimicrobial peptide functionalized Ti implant was improved obviously. The method used in this work is a feasible and promising strategy to win the race against invading bacteria and accelerate bone integration in orthopedic implantation. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3021-3033, 2018.

N-halamine-based multilayers on titanium substrates for antibacterial application.

Bacterial infection is one of the most severe postoperative complications leading to clinical orthopedic implants failure. To improve the antibacterial property of titanium (Ti) substrates, a bioactive coating composed of chitosan-1-(hydroxymethyl)- 5,5-dimethylhydantoin (Chi-HDH-Cl) and gelatin (Gel) was fabricated via layer-by-layer (LBL) assembly technique. The results of Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1HNMR) and X-ray photoelectron spectroscopy (XPS) showed that Chi-HHD-Cl conjugate was successfully synthesized. Scanning electron microscopy (SEM), atomic force microscope (AFM) and water contact angle measurements were employed to monitor the morphology, roughness changes and surface wettability of Ti substrates, which proved the multilayers coating formation. Antibacterial assay against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) revealed that the Gel/Chi-HDH-Cl modified Ti substrates most efficiently inhibited the adhesion and growth of bacteria. Meanwhile, in vitro cellular tests confirmed that Gel/Chi-HDH-Cl multilayers had no obvious cytotoxicity to osteoblasts. The study thus provides a promising method to fabricate antibacterial Ti-based substrates for potential orthopedic application.

Peptide LL-37 coating on micro-structured titanium implants to facilitate bone formation in vivo via mesenchymal stem cell recruitment.

Titanium (Ti) and Ti-alloys were widely used in clinic orthopedics, however, the insufficient bone formation surrounding Ti-based implants still limited their biological performances. Surface modification of Ti substrates is essential to improve their interactions with bone-forming cells and bone tissue. In this study, we modified Ti substrates by coating peptide LL-37 onto micro-structured Ti substrates and aimed to (i) induce mesenchymal stem cells (MSCs) migration both in vitro and in vivo, (ii) facilitate osteogenic differentiation of MSCs and new bone formation. The surface micro-structured Ti substrates with hydroxyapatite deposition were fabricated by a two-step method including micro-arc oxidation (MAO) and hydrothermal treatment. LL-37 was loaded on micro-structured Ti substrates with the assistance of polydopamine coating. We confirmed that surface-modified Ti substrates benefited viability, adhesion, migration and osteogenic differentiation of MSCs in vitro. In a femur-defect rat model, the surface-modified Ti implants effectively induced CD29+/CD90+ positive cells migration in one week after implantation. According to the results of H&E, Masson's trichrome staining and immunohistochemical staining of OCN, OPN and collagen I, the targeted Ti implants exhibited significant new bone formation after implantation for 4 weeks. These results indicate that the surface modification of Ti samples facilitated bone formation through MSCs recruitment. STATEMENT OF SIGNIFICANCE: The inherent surface bioinertness of titanium (Ti) and Ti-alloys still limits their biological performances in clinical applications. Recently, the strategy of mesenchymal stem cells (MSCs) recruitment has been proposed to improve the osteointegration of bone implants. Herein, we reports the surface modification of Ti implants from the point of MSCs recruitment. Peptide LL-37 was coated on micro-structured Ti substrates to (i) recruit MSCs, (ii) regulate bio-physiological performance of MSCs, and (iii) facilitate bone formation in vivo. Our results improve the understanding of the interaction between Ti implants and MSCs, and provide a promising strategy of MSCs recruitment in the design of bone repair related biomaterials.

Dummy template molecularly imprinted polymer for solid phase extraction of phenothiazines in meat based on computational simulation.

The 3D structures of two dummy templates and four phenothiazine drugs were studied by using computational simulation method. Then the two dummy templates were used to synthesize two molecularly imprinted polymers respectively. Results showed that the recognition abilities of the two polymers were consistent with the theoretical calculation. Then a solid phase extraction column was developed for extraction of the four phenothiazines in meat (pork, chicken) followed by determination with high performance liquid chromatography. The column showed high adsorption capacities (850-962ng analyte per milligram of polymer) and high recoveries (93-98%) to the four drugs, and could be recycled for sixty times. The limits of detection were in the range of 1.0-10ng/g, and the recoveries from the fortified blank samples were in the range of 70.3-96.1%. This is the first study reporting the use of molecularly imprinted polymer-based method for determination of phenothiazines residues in foods.