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BACKGROUND: As a coating material, chitosan can effectively improve biological properties of medical metal surfaces due to its excellent film-forming and metal binding abilities. However, the biological activity and osteoinductive ability of chitosan are insufficient. Graphene oxide can improve the mechanical properties and biocompatibility of various polymer materials, as well as promote osteogenic differentiation. The combination of chitosan and graphene oxide may have better biological properties and osteogenic activity. OBJECTIVE: To construct the graphene oxide-modified chitosan composite coating material, analyze the surface morphology, chemical composition, and physical properties of the coating material, as well as the effects of the coating materials on proliferation, adhesion, and osteogenic differentiation of osteoblasts. METHODS: The titanium surface was treated with 3-aminopropyltriethoxysilane to form silane groups on the surface, and then glutaraldehyde was used to cross-link chitosan with silane groups to prepare simple chitosan coating and graphene oxide/chitosan composite coating, respectively. The surface morphology, chemical structure and hydrophilic properties of the coatings were characterized by atomic force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and contact angle measurement system. Rat osteoblasts were seeded on the surface of the two materials, and the proliferation, spreading, and osteogenic differentiation of rat osteoblasts were analyzed by CCK-8 assay, scanning electron microscopy, and reverse transcription-polymerase chain reaction analysis. RESULTS AND CONCLUSION: (1) The thickness of the graphene oxide sheets was about 2 nm as measured by atomic force microscopy; the scanning electron microscopy showed that the surfaces of both coatings were smooth and dense, in which the chitosan molecules were closely arranged and the graphene oxide was uniformly distributed in the chitosan, while wrinkles appeared on the surface of chitosan due to the addition of grapheme. The contact angle of the graphene oxide-chitosan composite coating was significantly smaller than the chitosan coating alone (P < 0.05). (2) CCK-8 assay showed that the graphene oxide-chitosan composite coating better promoted the proliferation of osteoblasts compared with the chitosan coating alone. (3) The scanning electron microscopy showed that better spreading was found in osteoblasts on the surface of the graphene oxide-chitosan composite coating compared with the chitosan coating alone. (4) Reverse transcription-polymerase chain reaction analysis showed that the mRNA expression of alkaline phosphatase and Runx2 was significantly increased in the graphene oxide/chitosan composite coating group compared with in the chitosan coating alone group (P < 0.05). (5) These findings suggest that graphene oxide/chitosan composite coating had good biocompatibility, physicochemical, and osteoinductive properties. [ABSTRACT FROM AUTHOR]

BACKGROUND: Natural biopolymers have excellent biodegradability. Their structures are similar to natural extracellular matrix, which is conducive to tissue repair. Natural biopolymers have a great potential in developing new absorbable membranes. OBJECTIVE: To develop a new absorbable membrane for guided bone regeneration by incorporating 58S bioglass powders into alginate/chitosan composites and study the physical, chemical and biological properties. METHODS: Alginate/chitosan/bioglass composite membranes were prepared according to the concentration gradient of 0, 5, 7.5 and 10 g/L 58S bioglass. The groups were recorded as 0BG, 0.5BG, 0.75BG and 1BG composite membranes according to the concentration gradient. The morphology of each group of composite membranes was characterized by metallurgical microscope and scanning electron microscope. The physiochemical properties of the resultant polymers were assessed via Fourier transform infrared spectroscopy and swelling ratio in each group. The biological properties of the composite membranes were compared by in vitro degradation experiments, protein adsorption experiments, cell adhesion experiments, cell proliferation experiments and alkaline phosphatase activity tests in each group. RESULTS AND CONCLUSION: (1) Metallurgical microscope and scanning electron microscope showed that samples of each group had the typical porous structure of hydrogel, and the bioglass particles were embedded in the pores of the composite membrane. The porosity of all composite membranes was greater than 90%. The sequence was: 0BG > 0.5BG > 0.75BG > 1BG. (2) Fourier transform infrared spectroscopy exhibited the characteristic peaks of the polymer formed by alginate and chitosan and the evidence of the existence of bioglass in the polymer. The composite membranes with 58S bioglass powders showed certain advantages in swelling ratio, in vitro degradation and biological activity, and this advantage was more obvious with the increase of bioglass content. In particular, 0.75BG and 1BG composite membranes could exhibit a high level of osteogenic differentiation over a long period of time. (3) These results suggested that in the experimental research range, when the mass concentration of 58S bioglass was 7.5 and 10 g/L, the alginate/chitosan/bioglass composite membranes can achieve relatively excellent biological activity, and it has the potential to be applied in the study of guided bone regeneration. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

N・Heterocyclic modified ckdtosanJodine complex was prepared with chitosan through the mechanism of nucleophilic addition -elimination reaction to form imine with N-heterocyclic pyridinal, and then complexing with iodine under electrostatic attraction・ The structure of the product was characterized by ultraviolet-visiable spectroscopy (UV-Vis), fourier transform infrared spectroscopy (FTIR), X・ray diffraction (XRD)・ All the results demonstrated that the N・heterocycle modified chitosan-iodine complex has been successfully prepared・ The results of antibacterial activity in vitro showed that N-heterocyclic modified chitosan-iodine complex had strong antibacterial activities, and the inhibition zones of against Staphylococcus aureus and Escherichia coll were (26 ・ 2 ± 0. 3) mm and (19 ・ 8 ±0.3) mm, respectively ・ Therefore, N・heterocyclic modified chitosan iodine complex is expected to be developed as marine biological medical antibacterial dressing. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Forest Products Industry is the property of China Forest Products Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to directly adsorb accumulational lactic acid from muscular tissue, superparamagnetic chitosan-coated magnetic Fe3O4 particles (Fe3 O4@CS NPs) which holds the potential in lactic acid adsorption have be synthesized via solvothermal method. Fe3O4@ CS NP were characterized by a scanning e-lectron microscope (SEM),a fourier transform infrared spectroscopy (FTIR),a thermal gravimetric ana- lyzer (TGA), a superconducting quantum interference device (SQUID) and a dynamic light scattering (DLS). The SEM image showed Fe3O4@ CS NPs were spheroidal, the result indicated Fe3O4@ CSNPs consisted of 46% of CS in mass. Besides, Fe3O4@CS NPs were superparamagnetic. Fe3O4@CS NPs could link lactic acid by covalent and hydrogen binding. As a result, the adsorption effect was satisfactory which could get the adsorption ratio of (50.73±1.14)%. Meanwhile,there are nearly no cytotoxicity on human skeletal muscle cells of magnetic particles, showing their good compatibility. All the results show that Fe3O4@CS NPs hold a great potential in lactic acid removal in from muscular tissue. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) was introduced into the polyacrylamide/chitosan (PAM/CS) hydrogel system by free radical polymerization, and the PAM/CS/MoS2 composite polymer hydrogel with interpenetrating network structure was prepared. The composition and morphology of the hydrogels were analyzed by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and laser scanning confocal microscopy. The mechanical properties and hydrophilic properties were tested by a universal testing machine and a contact angle measuring instrument. Finally, the application of the composite hydrogel film in the field of humidity sensing was explored by a quartz crystal microbalance (QCM). The PAM/CS/MoS2-0.4 (mass of MoS2 in this system is 0.4 mg) composite hydrogel has a maximum compressive stress of 584.6 kPa and a maximum compressive strain of 83.8%. The introduction of MoS2 improves the hydrophilicity of the composite hydrogel. As the relative humidity of the environment increases from 11% to 95%, the frequency response of the QCM humidity sensor modified by the composite hydrogel film reaches a maximum of 2 642 Hz, and its sensitivity of 1% change of relative humidity is 31.45 Hz, which is expected to be applied in the field of humidity sensing. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oil spillage is one of the significant wellsprings of contamination. It can happen in both land and water. Their expulsion from marine and land environment is regularly difficult. This investigation considers the utilization of coconut and banana stem fibers as a feasible sorbent material for marine and land oil spill recuperation. Coconut and banana stem fibers have lumens, which increases their specific surface area available for oil sorption. These fibers are cheap and have low bulk density, which makes them reasonable for oil spill recuperation. Moisture content in coconut and banana stem fiber were found to be 4.44% and 5.44%, respectively. The oil sorption limit of coconut and banana stem fiber was improved by coating it with chitosan. The treated fibers showed a considerable enhancement in oil sorption capacity for coconut fiber (9.87%) and banana stem fiber (6.59%), according to the results. The characterization of the natural and coated fibers was completed utilizing scanning electron microscopy and Fourier transform infrared spectroscopy. Moisture content and oil sorption limit of the fibers were estimated. The test has confirmed that both cocont and banana stem fibers can be utilized as a potential sorbent material for oil spillage tidy up. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Novel green natural composites comprising of BF immobilized in CS (BFi-CS) were prepared and characterized by means of Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). It was observed that BF is not grafted to but widely dispersed and immobilized within the CS matrix by physical mean. The effect of pH on the controlled-release behavior of BF-i-CS was investigated using 1- and 2-naphthol as model pesticides. The results revealed that the release amount was found higher in acidic medium followed by neutral and basic medium. On average, the release behavior of 1- and 2-naphthol was found controlled, consistent and prolonged over a period of 36 and 30 h, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogel can significantly expand in water and maintain their original structures and properties. Hydrogels have a promising application in enrichment and separation of low concentration heavy metal ions, because of the large adsorption capacity, fast adsorption speed, easy analysis, rich source and being environmentally friendly. However, the traditional hydrogel adsorbents prepared from chitosan, cellulose and other natural polysaccharides have poor mechanical properties, so it is necessary to synthesize a hydrogel adsorbent having good mechanical properties, which restricte their application in heavy metal adsorption. In this work, cellulose-chitosan / polyacrylamide (Ce-Cs/PAAM) double network hydrogel was prepared by a one-pot method. 0.5 g of banana fiber cellulose and 0.5 g of chitosan were dispersed in 20 mL of 0.1 mol/L acetic acid (the precursor solution for the first network ) and stirred at 60 ℃ for 5 h. The chitosan could be dissolved quickly while the banana fiber cellulose was partially dissolved. Then 4.26 g of acrylamide (the precursor solution for the second network) and 3 mL of epichlorohydrin (crosslinking agent) were added into the solution by magnetic stirring at 25 ℃ for 1 h. After that, 0.02 g of N, N-methylene diacrylamide (crosslinking agent), 0.02 g of potassium persulfate (initiator), and 0.2 g of α-ketoglutaric acid (light initiator) were added to the mixed solution and stirred for 15 min.The first and second network were polymerized and crosslinked simultaneously. The obtained solution was placed at 25 ℃ for 24 hours. The two polymer networks generated upon UV-curing for 6 hours to further polymerized the second layer of networked (polyacrylamide) under the action of light initiator, followed by washing in deionized water twice a day for 7 days to produce a white opaque gel. Cellulose-chitosan (Ce-Cs) and polyacrylamide (PAAM) hydrogel were prepared as control. The structure of the three types of hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-Ray Diffractometer (XRD). The changes of functional group composition, surface structure, crystallization degree, mechanical properties, swelling properties and adsorption properties of samples were investigated. The results showed that the Ce-Cs / PAAM hydrogel was a three-dimensional porous and double network structure with excellent mechanical strength and toughness. Under the compressive strain of 90%, the maximum compressive stress was reached to 60 MPa. The swelling ratio in water was 9.56 mg/mg, and the swelling ratio in alkaline solution (pH 12) reached to 15.34 mg/mg. The maximum adsorption capacity of Cu2+ ions on Ce-Cs/ PAAM hydrogel was 312.4 mg/g (Qe) under the concentration of C0 at 350 mg/L, pH at 5.5 and adsorption time for 90 min. Compared with polyacrylic acid / humus double network hydrogel (151.00 mg/g), the adsorption capacity of sample for Cu2+ ions was increased significantly. Therefore, the results indicated that Ce-Cs /PAAM double network hydrogel may be a promising Cu2+ ions adsorbent. [ABSTRACT FROM AUTHOR]

The positively and negatively charged nanoparticles with pH responsiveness were prepared by biocompatible poly-γ-glutamic acid (γ-PGA) and chitosan (CS) , and were used to load the antibiotic amoxicillin. The structures and morphologies of the drug-loaded nanoparticles were characterized by Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffractometer (XRD) and Transmission Electron Microscopy (TEM). The pH responsive drug release of these nanoparticles to drug release and their toxicity to cells were investigated. The application of these two types of nanoparticles as drug carriers was also investigated from the aspects of anti-protein pollution and inhibition of Escherichia. coli and Staphylococcus aureus. Results showed that the sizes of surface charges can be easily tailored by adjusting the amount of γ-PGA and CS. Also, negatively charged nanoparticles displayed better performance of pH controlled drug release. Under simulated stomach environment, the sizes of the drug-loaded nanoparticles were between 200 nm and 300 nm and the cumulative release of amoxicillin was only 25%. However, in the simulated intestinal cell gap environment which was neutral or weakly alkaline, the mean particle size was increased to about 1 μm and the cumulative drug release was enhanced to 85%. In addition, the nanoparticles had a function of lowering the toxicity of drugs to normal cells by 20%, and they can improve the inhibitory effects on intestinal bacteria by about 42% compared to the free drug. [ABSTRACT FROM AUTHOR]