• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.441-448
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• 1998

Defined spatial localization of biomolecules on the polymer surface Is potentially powerful method to generate biocompatible surface. Photolithography and photochemistry can be used to immobilize peptides only al a given region of the surface. In this study, peptide RGDS, one of the endothelial cells recognition sites of fibronectin, was covalently immobilized on the polystyrene coated surface with micropattern. It was performed by photochemical reactivity of a synthesized N-hydroxysuccinimidyl phenyl azide. The micropatterning was confirmed by staining with fluorescent dye, aminoacetamido fluorescein. Endothelial cell adhesion was observed only on the RGDS immobilized areas.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2003.10a
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• pp.59-59
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• 2003

In recent, various functional coatings on artificial tooth implants have been conducted to enhance the bonding strength between implants and bones. Despite of these efforts, some previous reports argued that an adhesion strength between titanium implant and the final coatings like hydroxyapatite(HA) is weaker than the strength between coating and bone. In order to increase the adhesion force between the final coating and implant surface, TiN/DLC based functionally graded coating, which has higher mechanical strength than the titanium implant, was applied as a middle layer between titanium implant and final coating. Particularly we finally coated a biocompatible hydroxyapatite film on the DLC layer and examined the mechanical properties. As a result, TiN/DLC based functionally graded coating showed the higher adhesion strength compared with hydroxyapatite single layer coating on the titanium implant.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1631-1632
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• 2006

This paper reports on a flexible and biocompatible platinum thermoresistive temperature sensor for the application of an ultrasonic resonance thrombolysis device for ischemic stroke. The proposed flexible platinum temperature sensor consists of a polyimide substrate, a platinum thermoresistive element and a polyimide insulation layer. The temperature coefficient of resistance (TCR) and sensitivity of the designed temperature sensor were measured and calculated to be $2.63{\times}10^{-3}/^{\circ}C$ and $0.93^{\circ}C/sec$, respectively.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.252-253
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• 2006

The fabrication of complex-shaped parts out of Co-Cr-Mo alloy and 316L stainless steel by three-dimensional printing (3DP) was studied using two grades of each alloy with average particle size of 20 and $75\;{\mu}m$, respectively. To produce sound specimens, the proper 3DP processing parameters were determined. The sintering behavior of the powders was characterized by dilatometric analysis and by batch sintering in argon atmosphere at $1280^{\circ}$ for 2h. The 3DP process has successfully produced complex-shaped biomedical parts with total porosity of 12-25% and homogenous pore structure, which could be suitable for tissue growth into the pores.

• Journal of Pharmaceutical Investigation
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• v.30 no.2
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• pp.73-83
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• 2000

Polyethylene glycol (PEG) is a water soluble, biocompatible, non-toxic polymer and PEGylation is a well established technique for the modification of therapeutic proteins and peptides. PEG-protein drugs have been extensively studies in relation to therapies for various diseases: cancer, inflammation and others. The covalent attachment of PEG to proteins and peptides prolonged plasma half-life, reduced antigenicity and immunogenicity, increased thermal and mechanical stability, and prevented degradation by enzymes. Several chemical groups for general and site specific conjugation have been exploited to activate PEG for amino group, carboxyl group, and cysteine groups. PEGylation of many proteins and peptides have been studied to enhance their properties for the potential uses. Also, the different positional isomers in several PEG-proteins have shown the difference in vivo stability and biological indicating that the site of PEG molecule attachment is one of the important factor to develop PEG-proteins as potential therapeutic agents.

• Journal of Chest Surgery
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• v.27 no.5
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• pp.407-412
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• 1994

Congenital long-segment tracheal stenosis which involves nearly entire trachea and carina is very rare disease, but leads to life threatening obstruction in infancy and childhood. Symptoms are ranged from stridor and wheezing to severe cyanosis and respiratory failure. Routine chest X-ray is somewhat helpful to diagnose it, but definitive diagnosis can be made by bronchoscopy or tracheogram for severely narrowed tracheal lumen.Recently, we experienced a case of congenital tracheal stenois, type 1 by Cantrell classification with carinal involvement. After costal cartilage was designed as oval shaped flap and covered with pericardium, anterior and posterior augmentation was done with prepared costal cartilage.This patient died of respiratory failure at 13 days postoperatively, probably due to sustaining obstruction in association in with failure to make a sufficient widening at carinal level.Important issues in the management of congenital tracheal stenosis are rapid diagnosis, selection of appropriate surgical procedure, and detailed anesthetic schedule.In the future, more biocompatible material and more effective surgical procedures should be studied to reduce the surgical mortality and morbidity of the complicated tracheal stenosis.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.8-19
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• 1995

Ion beam enhanced deopsition(IBED) was adopted to synthesize biocompatible titanium oxide film. Structure characteristics of titanium oxide film were investigated by RBS, AES and XRD. The blood compatibility of the titanium oxide film was studied by measurements of blood clotting time and platelet adhesion. The results show that the anticoagulation property of titanium oxide film is improved significantly. The mechanism of anticoagulation of the titanium oxide film was discussed.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.1
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• pp.16-21
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• 2007

Many kinds of materials have been used up to now for vocal fold paralysis. Although silastic block has been the most popular material, some difficulties in carving, positioning, and placing have been the causes to find more easily applicable materials. Hy-droxylapatite, gelfoam, hyaluronic acid and fat have been suggested and used for this purposes with some limitations. During last decade, Gore-Tex was introduced and replacing old materials and showed good surgical results with less difficulties. This material is biocompatible and familiar to surgeons because it had been invented in 1960's. In addition it is easy to shape and place Gore-Tex into the window with many clinical experiences. In some problem cases, it is easy to remove from the body with less damage to surrounding tissue. The basic surgical techniques are as follows. 1) Creating window. 2) Positioning and placing the material. 3) Immobilizing the material and closing the window. The modified methods ae introduced in details with figures.

• Radioisotope journal
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• v.21 no.4
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• pp.46-54
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• 2006

Biocompatible and biodegradable hydrogels based on carboxymethyl cellulose(CMC) and polyethyleneglycol(PEG) were prepared far physical barriers for preventing surgical adhesions. These interpolymeric hydrogels were synthesized by a gamma irradiation crosslinking technique. The 1Scmxl.Scm of cecal serosa and adjacent abdominal wail were abraded with bane burr until tbe serosal surface was disrupted and hemorrhagic but not perforated. and the serosa of tbe cecum was sutured to the abdominal wall in 5mm apart from the injured sire. The denuded cecum was covered with either CMC/PEG hydrogels or solution from CMC/PEG hydrogel. Control rat serosa was not covered. Two weeks later. the rats were sacrificed and adhesion was scored on a 0-5 scale. No treatment showed the significantly higher incidence of adhesions than either CMC/BEC hydrogels or solution from CMC/PEG hydrogel. In conclusion, these studies demonstrate that CMC/BEG hydrogels have a function of prevention of intra abdominal adhesion in a rat model.

• Journal of the Korean Society of Industry Convergence
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• v.24 no.2_1
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• pp.79-89
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• 2021

Poly(lactic acid) (PLA) is considered as one of the most promising bio-based polymers due to its high strength, high modulus, good processability, transparency after processing, and commercial availability. This study aimed to investigate the mechanical, thermal, and migration properties of poly(lactic acid)/zeolite (10 phr) composites prepared with various biocompatible plasticizers, such as triethyl citrate(TEC), tributyl citrate(TBC), and poly(ethylene glycol)(PEG400), through differential scanning calorimetry(DSC), thermo-gravimetric analysis(TGA) and standard tensile testing. The incorporation of PEG400 significantly increased the elongation at break, and DSC results showed that the addition of plasticizers drastically decreased the T_g of PLA/zeolite composites and improved the melt flow and processability. Besides, it was found from TGA results that PLA/zeolites composites plasticized by TEC and TBC were more easily to be thermally degraded than the composites plasticized by PEG400.