• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.156.1-156.1
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• 2007

• Macromolecular Research
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• v.8 no.5
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• pp.199-208
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• 2000

The recent development of biodegradable polymers for drug delivery system (DDS) has been investigated. The biodegradable polymers for DDS are mainly discussed in two categories: one category is natural biodegradable polymers such as polysaccharides, modified celluloses, poly(${\alpha}$-amino acid)s, modified proteins, and microbial biodegradable polymers; the other is synthetic biodegradable polymers such as poly(ester)s, poly(ortho ester)s, poly(phosphazene)s, poly(anhydride)s, poly(alkyl cyanoacrylate)s, and multiblock copolymers. The bioconjugate polymeric drug delivery systems have been also proposed for the design of biocompatible polymeric controlled drug delivery.

• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.100-101
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• 1999

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.409.1-409.1
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• 2002

For the development of a biocompatible nano-scale drug carrier. hydrophilic polysaccharide pullulan was hydrophobized by the conjugation with fatty acid. The synthesized polymers were characterized by the measurements of fourier transform infrared (FT -IR) spectroscopy and 1H -nuclear magnetic resonance (NMR) spectroscopy. In aqueous solution. hydrophobically modified puliulan was self-assembled and structured into the core-shell type nanoparticles. (omitted)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.295.2-295.2
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• 2003

Lipid nanodispersion (LN) composed of biocompatible lipids and surfactants is an alternative parenteral drug delivery system especially for lipophilic drugs. It has been studied for versatile applications such as oral, parenteral, topical, ocular, vaccine, and peptide drug delivery. The purpose of this study was to produce a novel LN system for intravenous injection using the high pressure homogenization. (omitted)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.156-156
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• 2017

In this work, analysis of biocompatible TiO2 oxide multilayer by the XPS depth profiling was researched. the manufacture of the TiO2 barrier-type multilayer was accurately performed in a mixed electrolyte containing HAp, Pd, and Ag nanoparticles. The temperature of the solution was kept at approximatively $32^{\circ}C$ and was regularly rotated by a magnetic stirring rod in order to increase the ionic diffusion rate. The manufactured specimens were carefully analyzed by XPS depth profile to investigate the result of chemical bonding behaviors. From the analysis of chemical states of the TiO2 oxide multilayer using XPS, the peaks are showed with the typical signal of Ti oxide at 459.1 eV and 464.8 eV, due to Ti 2p(3/2) and Ti 2p(1/2), respectively. The Pd-3d peak was split into Pd-3d(5/2) and Pd-3d(3/2)peaks, and shows two bands at 334.7 and 339.9 eV for Pd-3d3 and Pd-3d5, respectively. Also, the peaks of Ag-3d have been investigated. The chemical states consisted of the O-1s, P-2p, and Ti-2p were identified in the forms of PO42- and PO43-. Based on the results of the chemical states, the chemical elements into the TiO2 oxide multilayer were also inferred to be penetrated from the electrolyte during anodic process.The structure characterization of the modified surface were performed by using FE-SEM, and from the result of biological evaluation in simulated body fluid(SBF), the biocompatibility of TiO2 oxide multilayer was effective for bioactive property.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.553-553
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• 2012

The artificial shells of hard inorganic nanocomposites on individual cells would protect the cells physically and chemically, and control cell division. These emerging properties could be combined with cell-surface functionalizations for applications to cell-based sensors and assays as well as for fundamental studies on single-cell biology. In this work, individual Chlorella cells were encapsulated within a silica/titania nanocomposite shell in a biocompatible fashion that utilized a designed peptide, RKKRKKRKKRKKDDDDDDDD, as a catalytic template for formation of both $SiO_2$ and $TiO_2$ on the cell surface. The cell viability was maintained, and the division of the encapsulated Chlorella cells was controlled. The cell viability was enhanced compared with the $TiO_2$-shell formation. In addition, the incorporation of $TiO_2$ to the shell made it possible to anchor the ligands of interest to the shell via catechol chemistry. All in all, the combination of biological $SiO_2$ and abiolgical $TiO_2$ for the shell formation gave more tunability of the artificial shells compared with the $SiO_2$ or $TiO_2$ shells only.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.513-519
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• 2007

A vesicle forming polymer, poly(sodium acrylamidoundecanoate) (PSAU) and a water-soluble distyrylbenzene- based fluorophore, TPADSB-C were synthesized and characterized by using UV-vis and photoluminescence (PL) spectroscopy. An inter-chain vesicle formation of PSAU was observed at ~0.01 g/L from N-phenyl naphthylamine fluorescence measurement with changing PSAU concentration in water. Above critical aggregation concentration of PSAU, optical properties of TPADSB-C were investigated to study the microenvironment modulation through dye incorporation in the polymeric vesicle. The emission of TPADSB-C in the presence of PSAU vesicles was blue-shifted and the PL quantum efficiency was increased to 90% due to the microenvironment (e.g. polarity) change in aqueous solution. This study shows that the polymeric vesicle containing molecular fluorophores has a great potential as an efficient, stable and biocompatible labeling tag in biological cell imaging.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.204-209
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• 2013

Objectives: The objective of this in vitro study was to evaluate and compare the cytotoxicity of four different root canal sealers i.e. Apexit Plus (Ivoclar Vivadent), Endomethasone N (Septodont), AH-26 (Dentsply) and Pulpdent Root Canal Sealer (Pulpdent), on a mouse fibroblast cell line (L929). Materials and Methods: Thirty two discs for each sealer (5 mm in diameter and 2 mm in height) were fabricated in Teflon mould. The sealer extraction was made in cell culture medium (Dulbecco's Modified Eagle's Medium, DMEM) using the ratio 1.25 $cm^2/mL$ between the surface of the sealer samples and the volume of medium in a shaker incubator. Extraction of each sealer was obtained at 24 hr, 7th day, 14th day, and one month of interval. These extracts were incubated with L929 cell line and 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay was done. Two-way ANOVA for interaction effects between sealer and time and Post-hoc multiple comparison using Tukey's test across all the 16 different groups were used for statistical analysis. Results: Apexit Plus root canal sealer was significantly less toxic than other sealers (p < 0.05) and showed higher cellular growth than control. Endomethasone N showed mild cytotoxicity. AH-26 showed severe toxicity which became mild after one month while Pulpdent Root Canal Sealer showed severe to moderate toxicity. Conclusions: Apexit Plus was relatively biocompatible sealer as compared to other three sealers which were cytotoxic at their initial stages, however, they became biocompatible with time.

• Polymer(Korea)
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• v.35 no.3
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• pp.223-227
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• 2011

Stimuli-responsive polymers have been investigated as the materials playing the critical roles in various applications. Thermoresponsive graft copolymers, poly (N-isopropylacrylamide)-g-hyaluronic acid (PNIPAAm-g-HA) and elastin-like peptide-g-hyaluronic acid (ELP-g-HA), were synthesized by coupling carboxylic polymers (PNIPAAm-COOH or ELP) to biocompatible HA through amide linkages. Thermoresponsive behavior was observed in both the copolymers, and the results of turbidity measurement were consistent with the results of rheological examination. Among the two copolymers, the ELP graft copolymer shows less cooperative LCST transition than the PNIPAAm case. As the content of graft chains of PNIPAAm and ELP increases, viscosity increases, and the increase was larger in PNIPAAm case at a graft content. These results shows us that the introduction of grafts provides thermosensitivity to biocompatible HA, whose characteristics can be engineered.