• Corrosion Science and Technology
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• 제8권2호
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• pp.62-67
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• 2009

Ti and Ti-alloys have good biocompatibility, appropriate mechanical properties and excellent corrosion resistance. However, the widely used Ti-6Al-4V is found to release toxic ions (Al and V) into the body, leading to undesirable long-term effects. Ti-6Al-4V has much higher elastic modulus (100 GPa) than cortical bone (20 GPa). Therefore, titanium alloys with low elastic modulus have been developed as biomaterials to minimize stress shielding. The electrochemical behavior of surface-modified and MC3T3-E1 cell-cultured Ti-30(Nb,Ta) alloys with low elastic modulus have been investigated using various electrochemical methods. Surfaces of test samples were treated as follows: $0.3{\mu}m$ polished; $25{\mu}m$, $50{\mu}m$ and $125{\mu}m$ sandblasted. Specimen surfaces were cultured with MC3T3-E1 cells for 2 days. Average surface roughness ($R_a$) and morphology of specimens were determined using a surface profilometer, OM, and FE-SEM. Corrosion behavior was investigated using a potentiostat(EG&G PARSTAT 2273), and electrochemical impedance spectroscopy was performed (10 mHz to 100 kHz) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The microstructures of the Ti-30(Ta,Nb) alloys had a needle-like appearance. The $R_a$ of polished Ti-30Ta and Ti-30Nb alloys was lower than that of the sandblasted Ti alloy. Cultured cells displayed round shapes. For polished alloy samples, cells were well-cultured on all surfaces compared to sandblasted alloy samples. In sandblasted and cell-cultured Ti-30(Nb,Ta) alloy, the pitting potential decreased and passive current density increased as $R_a$ increased. Anodic polarization curves of cell-cultured Ti alloys showed unstable behavior in the passive region compared to non-cell-cultured alloys. From impedance tests of sandblasted and cell-cultured alloys, the polarization resistance decreased as $R_a$ increased, whereas, $R_a$ for cell-cultured Ti alloys increased compared to non-cell-cultured Ti alloys.

• 지구물리와물리탐사
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• 제11권3호
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• pp.167-176
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• 2008

태평양 해양 지각판과 인도-호주 대륙 지각판간 섭입작용에 의해 형성된 남태평양 라우분지는 활동성 후열도분지로서 해저열수광상이 부존할 가능성이 매우 높은 지역이다. 한국해양연구원은 라우분지를 대상으로 다중음향측심장비(EM120)을 이용하여 정밀지형조사를 실시하여 열수활동이 활발할 것으로 예측되는 해저 지각 확장축 주변지역 (FRSC)과 해저화산 지역(MTJ)을 선별하였다. 또한, 표층 및 심해견인 자력탐사결과를 토대로 저 자기이상 현상을 나타내는 열수광체 지역을 선정하였다. 표층 및 심해 견인 자력탐사 결과 해령에서 주로 나타나는 Central Anomaly Magnetization High(CAMH)가 FRSC-2 지역에서 관측되었으며, MTJ-1 지역에서는 열수분출작용으로 추정되는 저자화이상이 발견되었다. CTD 시스템을 이용하여 열수 플룸 추적자인 투명도, 수소이온(pH), 미생물생체량(ATP), 메탄$(CH_4)$농도를 실시간으로 측정한 결과 FRSC-2와 MTJ-1 지역은 현재 매우 활발한 화산 활동이 진행되고 있음을 알 수 있었다. 이 지역에서 채취한 열수분출공과 기반암 시료는 이 지역에서 열수활동이 진행되었거나 진행되고 있으며, 실제로 열수 광체가 부존하고 있음을 확인할 수 있었다. 첨단 해저면 영상장비를 사용하지 않고도, 전통적인 해양 지구물리탐사 방법이 해저열수광상의 탐지에 비용 효과적인 탐사방법임을 알 수 있었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2016년도 추계학술대회 논문집
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• pp.197-197
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• 2016

Commercially pure titanium (CP Ti) and Ti-6Al-4V alloys have been widely used for biomedical applications. However, the use of the Ti-6Al-4V alloy in biomaterial is then a subject of controversy because aluminum ions and vanadium oxide have potential detrimental influence on the human body due to vanadium and aluminum. Hence, recent works showed that the synthesis of new Ti-based alloys for implant application involves more biocompatible metallic alloying element, such as, Nb, Hf, Zr and Mo. In particular, Nb and Hf are one of the most effective Ti ${\beta}-stabilizer$ and reducing the elastic modulus. Plasma electrolyte oxidation (PEO) is known as excellent method in the biocompatibility of biomaterial due to quickly coating time and controlled coating condition. The anodized oxide layer and diameter modulation of Ti alloys can be obtained function of improvement of cell adhesion. Manganese(Mn) plays very important roles in essential for normal growth and metabolism of skeletal tissue in vertebrates and can be detected as minor constituents in teeth and bone. Radio frequency(RF) magnetron sputtering in the various PVD methods has high deposition rates, high-purity films, extremely high adhesion of films, and excellent uniform layers for depositing a wide range of materials, including metals, alloys and ceramics like a hydroxyapatite. The aim of this study is to research the Mn coatings on the micro-pore formed Ti-29Nb-xHf alloys by RF-magnetron sputtering for dental applications. Ti-29Nb-xHf (x= 0, 3, 7 and 15wt%, mass fraction) alloys were prepared Ti-29Nb-xHf alloys of containing Hf up from 0 wt% to 15 wt% were melted by using a vacuum furnace. Ti-29Nb-xHf alloys were homogenized for 2 hr at $1050^{\circ}C$. Each alloy was anodized in solution containing typically 0.15 M calcium acetate monohydrate + 0.02 M calcium glycerophosphate at room temperature. A direct current power source was used for the process of anodization. Anodized alloys was prepared using 270V~300V anodization voltage at room. Mn coatings was produced by RF-magnetron sputtering system. RF power of 100W was applied to the target for 1h at room temperature. The microstructure, phase and composition of Mn coated oxide surface of Ti-29Nb-xHf alloys were examined by FE-SEM, EDS, and XRD.

• Reproductive and Developmental Biology
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• 제34권3호
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• pp.143-151
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• 2010

Pluripotency of human embryonic stem cell (hESC) is one of the most valuable ability of hESCs for applying cell therapy field, but also showing side effect, for example teratoma formation. When transplant multipotent stem cell, such as mesnchymal stem cell (MSC) which retains similar differentiation ability, they do not form teratoma in vivo, but there exist limitation of cellular source supply. Accordingly, differentiation of hESC into MSC will be promising cellular source with strong points of both hESC and MSC line. In this study, we described the derivation of MSC like cell population from feeder free cultured hESC (hESC-MSC) using direct differentiation system. Cells population, hESC-MSC and bone marrow derived MSC (BM-MSC) retained similar characteristics in vitro, such as morphology, MSC specific marker expression and differentiation capacity. At the point of differentiation of both cell populations, differentiation rate was slower in hESC-MSC than BM-MSC. As these reason, to verify differentially expressed molecular condition of both cell population which bring out different differentiation rate, we compare the molecular condition of hESC-MSC and BM-MSC using 2-D proteomic analysis tool. In the proteomic analysis, we identified 49 differentially expressed proteins in hESC-MSC and BM-MSC, and they involved in different biological process such as positive regulation of molecular function, biological process, cellular metabolic process, nitrogen compound metabolic process, macromolecule metabolic process, metabolic process, molecular function, and positive regulation of molecular function and regulation of ubiquitin protein ligase activity during mitotic cell cycle, cellular response to stress, and RNA localization. As the related function of differentially expressed proteins, we sought to these proteins were key regulators which contribute to their differentiation rate, developmental process and cell proliferation. Our results suggest that the expressions of these proteins between the hESC-MSC and BM-MSC, could give to us further evidence for hESC differentiation into the mesenchymal stem cell is associated with a differentiation factor. As the initial step to understand fundamental difference of hESC-MSC and BM-MSC, we sought to investigate different protein expression profile. And the grafting of hESC differentiation into MSC and their comparative proteomic analysis will be positively contribute to cell therapy without cellular source limitation, also with exact background of their molecular condition.

• 한국발생생물학회지:발생과생식
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• 제14권4호
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• pp.233-241
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• 2010

사람의지방줄기세포는지방조직내에존재하는 줄기세포로 얻기 쉽고, 골수줄기세포와 유사한 특징을 가지고 있다. 그러나 지방을 추출하는 과정, 공여자의 나이, 체질량, 추출 부위에 따라 세포의 특성이 달라지며, 이질적인 세포군을 얻게 된다. 따라서 본 연구에서는 허벅지 지방에서 유래한 줄기세포 특성 분석 및 중배엽, 내배엽성 세포로의 분화능을 알아보았다. 허벅지 유래 줄기세포는 골수줄기세포와 유사한 섬유아세포와 유사한 모양을 보였으며, 체외에서 56.5번의 분열을 하였고, 약 $5{\times}10^{22}$개의 세포를 얻을 수 있었다. 이들은 SCF, Oct4, nanog, vimentin, CK18, FGF5, NCAM, Pax6, BMP4, HNF4a, nestin, GATA4, HLA-ABC, HLA-DR과 같은 유전자를 발현하였으며, Oct4, Thy-1, FSP, vWF, vimentin, desmin, CK18, CD54, CD4, CD106, CD31, a-SMA, HLA-ABC 등과 같은 단백질을 발현하였다. 또한 이들은 지방, 골, 연골 세포와 같은 중배엽성 세포로 분화하였고, 더욱이 인슐린 분비세포와 같은 내배엽성 세포로도 분화하였다. 결론적으로, 사람의 허벅지 유래 줄기세포는 골수 줄기세포와 유사하게 체외에서 증식이 가능하였으며, 유전자 및 단백질 발현 패턴을 가지고 있었으며, 다양한 세포로 분화 가능하였다. 이러한 결과로 미루어 보아 허벅지 지방유래 줄기세포는 골수 줄기세포를 대체할 수 있는 세포치료제의 재료가 될 수 있을 것으로 사료된다.

• 대한미생물학회지
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• 제21권3호
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• pp.399-406
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• 1986

This study was performed to establish human plasmacytoma cell line as the partner cells for producing human hybridoma. Bone marrow cells from a multiple myeloma patient from Seoul National University Hospital, Korea were cultured and established as the cell line, named as HMC-BM4. HMC-BM4 cells were cultivated in RPMI 1640 media containing 8-azaguanine(8-AG; gradually increasing concentration from $1\;{\mu}g/ml$ to $20\;{\mu}g/ml$). 8-AG resistant cells were collected and cloned by limiting dilution. Each clone was divided and tested to die in hypoxanthine, aminopterine and thymidine (HAT) selection media. Finally one clone was selected and named as HMC-AR, which was sensitive to HAT selection media. HMC-AR cells showed typical morphology of plamacytoma in Wright staining. No cell formed the rosette with sheep erythrocytes. Surface membrane $\mu$ heavy chain was detected in 20% of HMC-AR cells and cytoplasmic $\mu$ heavy chain in 90% of them by direct immunofluorescent staining. Ia-like antigen was found in 90% of HMC-AR cells by indirect immunofluorescent staining using anti-Ia-like antigen monoclonal antibody, 1BD9-2. And about $1.0\;{\mu}g/ml$ of human $\mu$ heavy chain was detected in the 3-day culture supernatant of HMC-AR cells. 88% of cells contained 46 chromosomes. Mycoplasma was not detected in HMC-AR cells by Hoechst 33258 staining. This cell line would be used for making hybridomas secreting human monoclonal antibody.

• 한국수산과학회지
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• 제22권3호
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• pp.129-137
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• 1989

1986년 12월 1일 강원도 명주군 옥계면 김진삼 이앞 연안에서 삼중책망으로 채포한 성숙한 도루묵을 이용하여 현장(선상)에서 인공수정시켜, 실내 사육실로 운반한 후 난발생과정과 부화자치어의 형태를 연구하였다. 난은 구형이고 침성점착난이며 난경은 $3.1\~3.4$mm(평균 3.3 mm, n=10)이었고, 많은 소유구를 가진다. 자연산난된 알은 지름이 약 4 cm인 알덩이를 형성하였다. 수온 $8.7\~12.3^{\circ}C$ 범위에서 수정 후 65일만에 부화되었다(적산수온 $663\~902^{\circ}C$). 부화직후 자어는 전장 $8.5\~10.2$ mm 범위이며, 근절수는 11+40(?)이었고, 가슴지느러미 줄기 5개가 발달하여 있었다. 부화 후 24일 째 전장 19.4 mm 자어는 난황을 완전히 흡수하였고, 배지느러미의 원기가 나타났다. 부화 후 32일째 전장 23.4 mm는 각 지느러미 줄기가 완성되고 치어기에 달한다. 부화 후 56일째 전장 29.9 mm의 치어는 체형이 거의 성어와 닮으며 체측에 4개의 흑색소포덩이가 나타났다. 전새개골 극은 전장 15.6 mm일때 4개가 나타났고 전장 24.4 mm에서 5개가 생겼다. 가슴지느러미는 전장 15 mm 전후에 둥근형에서 성어의 형태로 바뀌었다. 도루묵의 자어는 항문의 위치가 몸중앙보다 앞쪽에 위치한 점과 꼬리의 배쪽 가장자리를 따라 흑색소포가 발달한 점이 배도라치류의 자어와 닮았으나, 전새개골에 극을 가지고 있어 극이 없는 배도라치류의 자어와 구별되었다.

• 한국임상수의학회지
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• 제16권2호
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• pp.309-320
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• 1999

Medial patellar luxation in dogs is one of the most common patellar problems presented to the veterinary practitioner. It is observed in toy and miniature breed and the majority of cases is a congenital form. Because of extensor mechanism's instability, it causes deformity and disorder in the growth of the affected limb when the luxation is left without treatment As lameness is not easily detectable in puppies, early diagnosis and correction are essential for therapy. Up to now, there has not been any reports refering to the diagnostic methods and the optimal age for correction in young dogs. Thirteen 45-90 days old puppies, have grade I and/or II medial patellar luxation. Only by palpation, all 13 dogs were diagnosed of patelar luxation. Skyline radiographic view was useful to interpret patellar morphology and depth of trochlear groove only above 60 days old. However, it was difficult to make definite diagnosis patellar luxation. The caudocranial and lateral radiographic view as well as ultrasonographic skyline view were not showed of patellar luxation. 2 puppies had unilateral patellar luxation and 11 puppies had bilateral patellar luxation which more serious on the left than on the right. Only 3 puppies among 11 puppies with bilateral patellar luxation were observed of lameness degree 1. Regardless of grade of patellar luxation and lameness, we performed trochlear chondroplasty using a U-shape sculpture blade to minimize cartilage injury, transposition of tibia tuberosity with No. 1 Supramid to align extensor mechanism and lateral imbrication. After surgery, we examined the operated animal daily for 10 days and on 15, 30 and 60 days after surgery respectively. After operation, pain and fever became normal on 7 days, swelling on 10 days, respectively. On 10 days after surgery, dogs showed normal standing position, and normal walking was observed in 15 days after surgery. In force plate analysis, the operated legs were normal weight bearing at 30 days after operation. After surgery, not only patellar luxation and clinical signs have been gradually reduced but also bone growth have become normal without showing growth physeal plate injury. The survival rate of puppies over 62 days old was 100%, while 42-45 days old 37.5%. The above results suggest that optimal age for surgical correction of congenital medial patellar luxation is recommended over 60 days old. In conclusion, combination of trochlear chondroplasty, transposition of tibia tuberosity, and lateral retinacular imbrication is appropriate for over 60 days old puppies to efficiently correct patellar luxation.

• 대한구순구개열학회지
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• 제6권1호
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• pp.1-15
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• 2003

이차골 이식술을 시행 받은 구순 구개열을 가지는 성인 남자 20명의 두부계측방사선 사진을 McNamara씨 분석법을 중심으로 하여 계측한 결과는 다음과 같다. 구순 구개열 환자에서 Na. perpendicualr to point A칼은 글.98±5.70, SWh angle 값은 76.45±4.69, Pogonion to Na. perpendicular간은 -6.38± 6.73을 나타내었다. Effective maxillary length는 85.6±4.42, effective mandibular length 값은 123.88±7.10을 보였고 하악각은 29.9±5.09, facial axis angle은 5.53±2.03으로 관찰되었다. Point A에 대해 상악 전치의 돌출도는 3.95±2.74의 값을 보였다.

• Journal of Periodontal and Implant Science
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• 제37권1호
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• pp.115-124
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• 2007

Silica is known as a promising osteoconductive material, and polycaprolactone is a bioactive and degradable material. The purpose of this study was to monitor the differentiation of MC3T3-E1 cells cultured on the layer-built silica/poly caprolactone non-woven fabric produced by electrospinning. Non-woven fabric (silica, polycaprolactone, PSP, SPS) was made by electrospinning and they were inserted in the 48 well cell culture plate. MC3T3-E1 cells were prepared by subculture. Cells were seeded to each well $1{\times}10^5$ concentration per well. Dulbecco's modified eagle medium with 10% FBS and 1% antibiotic-antimycotic solution was used. Confocal laser scanning microscope was taken 4 hours after incubation (95% air. 5% $CO_2$, $37^{\circ}C$). Cell proliferation was monitored by spectrophotometer on 1, 7, 14 days, and the morphology of the growing cells was observed by field emission scanning electron microscope. To monitor the differentiation of osteoblasts on the materials, MC3T3-E1 cells were incubated in 48 well culture plate after seeding with the density of $1{\times}10^5$ concentration. Then ELISA kit & EIA kit were used on to assess osteocalcin and osteopontin expression respectively. The other conditions were the same as above. MC3T3-E1 cells were proliferated well on all of the materials. There were no statistical differences among them. The osteopontin expression of silica, PSP, SPS was significantly higher than other groups on day 3 (p/0,05), but after that time, there were no statistically signigicant differences. The osteocalcin expression was significantly higher in silica and PSP than other groups on day 14. These findings show that PSP was as good as silica on the effect of osteoblast differentiation. The PSP non-woven fabric may have the possibility as bone graft materials.