Exploration of natural compound for the treatment of dental-related problems are gaining of interest for enhancing therapeutic efficacy of the drugs delivery system. In this study, we have prepared terpenoid, which have been isolated from Myrmecodia pendens Merr & Perry from Papua Island, Indonesia, to be encapsulated in Polylactic-co-glycolic acid (PLGA), as the most widely used biodegradable polymer for biomedical applications, through one step single-emulsion method followed by subsequent coating by poly (vinyl alcohol) (PVA). The resultant of terpenoid-loaded PLGA microparticles were characterized systematically through scanning electron microscope and Fourier-transform infrared spectroscopy. In vitro drug release test was evaluated through dialysis method. Antibacterial test was conducted against Enterococcus faecalis as a model for persistent bacteria that causes root canal infections. The results showed that terpenoid-loaded PLGA microparticles were developed in spherical morphology with an average particle size of around 1-2μm. Terpenoid released from PLGA compartment at pH 6.5 and temperature of 37°C through a controlled-release profile mechanism with enhanced prolonged release. The bacterial assay result showed that terpenoid-loaded PLGA microparticles could reduce Enterococcus faecalis, effectively. Eventually, these result show that terpenoid-loaded PLGA microparticles as unique natural product-based extract could be developed as a potential naturally-based drug for dental-related diseases applications.

Bacterial cellulose-based carbon nanotube has been synthesized by catalytic graphitization method. Bacterial cellulose (BS) is a source of cellulose produced from fermentation of medium by Acetobacter xylinum. Since it contains unbranch polymer linked by β-1.4 glucopyronose with hydroxil groups, BS is able to use as precursor in synthesis of carbon nanotube. Due to catalytic graphitization, chitosan served as coupling agent and dispersant of catalyst and various concentration of catalyst FeCl3.6H2O also were used. Graphitization was conducted in furnace with inert nitrogen gas atmosphere at 800°C for 2 hours. SEM-EDS were used to evaluate the morphology and semi-quantitative analysis of sample. TEM was used to determine the microstructures and crystallographic. When the chitosan was added 0.5%, its served as coupling agent and dispersant of catalyst with BS. Chitosan improved physical properties, relieved its brittleness, and caused the optical properties of BS. Catalyst of FeCl3.6H2O was used to assist the formation and growth of carbon nanotube. The amount of carbon was not affected by time aging. 0.1 M FeCl3.6H2O was the optimum concentration to produce carbon nanotube with 81, 58% the mass of carbon, plane orientation (002) (100) and the diameter of carbon nanotube is 25 nm.

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Various bioceramic materials including zirconia and hydroxyapatite have been developed for various applications. Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) is one of the most interesting features of calcium phosphate-based bioceramic that widely used in various applications especially for bio-application, bone engineering, and dentistry. However, the applications of pristine HAp have limited due to low load bearing applications. The wet chemical precipitation techniques was used to synthesize the solids based on zirconia. Hydroxyapatite and zirconia powder (0-30 weight %) were mixed homogeneously. Structure and morphological were characterized by SEM JEOL-JSM-T330A. The presence of functional group was observed by FTIR. Hardness value of material was measured by using Vickers hardness test measurement. Through this techniques, pure hydroxyapatite precipitate was obtained. Sintering temperature is an important factor that could influence the hardness of zirconia-doped hydroxyapatite. Based on the SEM observation, zirconia-doped hydroxyapatite were developed in blended morphology. FTIR results shows the interaction between hydroxyapatite and zirconia. Increasing zirconia increased the hardness value of zirconia-doped hydroxyapatite. Eventually, these ceramic-based materials could be developed for dental materials applications.

MAGNETIC REDUCED GRAPHENE OXIDEAS ADVANCED MATERIALS FORADSORPTION OF METAL IONS. Magnetic Reduced Graphene Oxide (MRGO) is graphene-based material that modified by introducing iron oxide nanoparticles onto the surface of graphene oxide (GO). MRGO exhibit some unique and advanced properties and characteristic including high surface area, superparamagnetic characteristics and adsorption ability against ions and molecules. In this research, MRGO was prepared by the Hummers method, followed by reacting ferrochloride tetrahydrate and ferrichloride hexahydrate through co-precipitation method for the formation of iron oxide nanoparticles on the GO surface. MRGO was prepared with various composition of ferrochloride tetrahydrate. Furthermore, the resultant of MRGO was characterized by Scanning Electron Microscope (SEM), Fourier-transform Infrared (FT-IR) Spectroscopy, and Atomic Adsorption Spectroscopy (AAS). Adsorption characteristics test was conducted against electroplating waste-based metal ion. The SEM results showed that GO exhibited the layered structure meanwhile MRGO exhibit as Feƒ O 4-modified GO layered surfaces. MRGO made by different ferrochloride tetrahydrate differed in the iron oxide nanoparticles formation on the surface of GO. Increasing the composition of ferrochloride tetrahydrate increased the formation of iron oxide nanoparticles. Moreover, MRGO (FeCl‚ .4H‚ O 0.0064 M) is successfully applied as nickel metal ion adsorbents with the adsorption ability of 78,24%. This result showed that MRGO have a potential prospect as an effective and efficient advanced adsorbent material candidate.

Formulation of nanoencapsulation of antibacterial metabolites from the fermentation of actinomycete strain designed as TP5 has been carried out. Nanoencapsulated formulations performed with Na alginate polysaccharides obtained from brown seaweed can maintain the antibacterial metabolite activity. This study aims to enhance antibacterial activity in nanoencapsulated formulations of antibacterial metabolites with ionic gelation technique using Na alginate and CaCl2. The nanocapsules were prepared by combining the extracellular secondary metabolite Nocardia sp. TP5 with the encapsulation sourced from Na alginate and CaCl2 by ionic gelation technique. The manufacturing methods include fermentation of Nocardia sp. TP5, nanoencapsulated formulation by varying the concentration and ratio of Na alginate, CaCl2, antibacterial metabolites, as well as analysis of nanocapsules. The analysis and characterization of nanoencapsulation using SEM-EDS and PSA included: surface morphology, particle size, chemical constituents, and zeta potential, as well as antibacterial testing against Escherichia coli and Staphylococcus aureus. The results showed that the best-nanoencapsulated formula contains the composition of Na alginate 0.3%, CaCl2 0.06% with a ratio of Na alginate: CaCl2: antibacterial metabolite is 2: 4: 1. The capsule particles formed are evenly distributed over the entire surface with a particle size of 425 nm, zeta potential of -27 mV, and antibacterial activity inhibited the growth of E. coli and S. aureus by 20 and 21 mm, respectively. The variation of the appropriate concentration ratio of Na alginate and CaCl2 greatly affects the uniform nanocapsules size and increases the antibacterial activity.

Erratum: "Magnetocaloric effect in La 0.7 Ca 0.3 MnO 3 nanotube arrays with broad working temperature span" [J. Appl. Phys. 117, 104304 (2016) Abstract. Durability is one of the most important issues that are still being a hindrance for commercialization of polymer electrolyte membrane fuel cell (PEMFC). In this study, the degradation of PEMFC using multiwall carbon nanotube supported Pt catalyst (Pt/CNT) was investigated under dynamic load cycle procedure. The degradation was characterized by current density-voltage curves, cross-sectional scanning electron microscopy (SEM) images, and Fourier transforms infrared spectroscopy (FTIR) spectra. The load-cycle procedure was carried out for 50 cycles, where one cycle consisted of three steps (OCV-load current-constant voltage). An analysis of cell overpotentials indicated that the predominant source of performance degradation was due to ohmic losses, especially significant increase in the area specific resistance (R a ). After 50 cycles, R a was calculated three times higher than that before durability test, from 0.67 to 1.74 Ωcm 2 . Based on the results from SEM images and FTIR spectra, there was no evidence of membrane degradation or thinning. Noticeable degradation was only observed from the increase in the interface gap between membrane, catalyst layer, and gas diffusion layer.