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다공크기에 따라 수핵세포가 파종된 PLGA 지지체의 압축강도에 관한 연구
홍희경 ( Hee Kyung Hong ),김순희 ( Soon Hee Kim ),이선경 ( Seon Kyoung Lee ),이영현 ( Young Hyun Lee ),김수진 ( Soo Jin Kim ),김온유 ( On You Kim ),이동원 ( Dong Won Lee ),이종문 ( John M. Rhee ),손영숙 ( Young Sook Son ),강길선 ( 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.4
Tissue engineering has the possible to improve upon current techniques for intervertebral disc repair. A key component in tissue engineering for disc regeneration is the scaffold that serves as a template for cell interaction and the formation of extracellular matrix to provide structural support to the newly formed tissue. Recently developed scaffolds, Poly(lactide-co-glycolide)(PLGA) most widely used due to its advantages such as good biocompatibility, controllable rate of degradation and metabolizable degradation products. We measured compression strength of scaffolds with various pores to select suitable pore for tissue-engineering bio-disc. PLGA scaffolds were prepared by solvent casting/salt-leaching. NP cell were harvested from the disc of adult female rabbit. These cells were seeded in prepared PLGA scaffold and cultured in DMEM mdeium supplimented, 10% FBS, 1% antibiotic antinycotics for 1, 4, 6 weeks. We Morphology of cellular adhesion and extracellular matrix production were confirmed by scanning electron microscope(SEM). According to our result, the compression strength of scaffold decreased with increasing porogen size.
배출허용기준 강화에 따른 차속별 경유 중형트럭의 유해대기오염물질 배출특성
홍희경 ( Hee Kyoung Hong ),정성운 ( Sung Woon Jung ),손지환 ( Ji Hwan Son ),문태영 ( Tae Young Moon ),이상은 ( Sang Eun Lee ),문선희 ( Sun Hee Moon ),윤현진 ( Hyun Jin Yoon ),김정수 ( Jeong Soo Kim ),김정화 ( Joung Hwa Kim ) 한국분무공학회 2015 한국액체미립화학회지 Vol.20 No.2
This study was designed to investigate the emission characteristics of unregulated pollutants (Aldehyde, VOCs, PAHs) as well as regulated pollutants (CO, HC, NOx and PM) from diesel medium-duty trucks. The emission characteristics of unreg- ulated and regulated pollutants were assessed based on regulation standards (EURO 4 and EURO 5) and intake weight (2.5 ton and 5 ton). The results show that unregulated and regulated pollutants remained almost unchanged at higher speeds but decreased at below 23.5 km/h. Reduction in unregulated and regulated pollutants was noticeable in vehicles of recent regu- lation standards and light intake weight. The analysis of aldehyde using UPLC showed that formaldehyde and acetaldehyde of aldehyde were most dominant. The GC/MS analysis showed that benzene, toluene, ethylbenzene and xylene of VOCs was over 80% followed by toluene, xylene, ethylbenzene and benzene. In addition, the analysis of PAHs using GC/TOF-MS indi- cated that bi- and tricyclic aromatic ring of aromatic compounds was 73% and 53% at 2.5 ton and 5 ton vehicles, respec- tively. The results of this study will be contributed to establish HAPs inventory.
함량별 DBP 스폰지에서 골수간엽줄기세포를 이용한 조직공학적 골분화 유도
홍희경 ( Hee Kyung Hong ),김순희 ( Soon Hee Kim ),이선경 ( Seon Kyoung Lee ),김대성 ( Dae Sung Kim ),최진희 ( Jin Hee Choi ),이동원 ( Dong Won Lee ),이종문 ( John M Rhee ),손영숙 ( Young Sook Son ),강길선 ( Gil Son Khang ) 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.4
Demineralized bone particle(DBP) that affects to cell proliferation and differentiation has been used as biomaterials. Bone marrow stromal cells(BMSCs) exhibit multiple traits of a stem cell population, and they can expand many times in vitro and be induced to differentiate into multiple cell types. In this study, we evaluated the effect of type of medium and contents DBP sponge on bone differentiation of rat BMSCs. Growth medium was consisted of DMEM, 10% FBS, 1% antibiotic antinycotics and Osteogenesis medium added to β-glycerophosphate 10 mM, L-ascorbic acid, dexamethasone 10-8 M, vitamin D3 10-8 M. DBP sponge were prepared by freeze-drying method from 1, 2 and 3 wt% DBP solution. BMSCs were harvested from the femurs of adult female Fischer rat. The effect of DBP sponge on the proliferation and ostegenesis of rat BMSCs were assessed in culture using the MTT assay, SEM, ALP assay, and RT-PCR was conducted to confirm mRNA expression of ALP and osteocalcin for osteogenic marker. According to our results, the cell viability and the quantity of ALP in 3 wt% DBP sponge were superior to other sponges. The osteogenesis medium provided the better osteogenesis effect than the growth medium. We concluded that osteogenesis medium and 3 wt% DBP sponge will be useful to bone differentiation using 3 wt% DBP sponge.
케라틴/PLGA 복합체 필름의 적층 원통형 지지체가 섬유륜 재생에 미치는 영향
이선경(Seon Kyoung Lee),홍희경(Hee Kyung Hong),김수진(Su Jin Kim),김용기(Yong Ki Kim),이동원(Dong Won Lee),강길선(Gil Son Khang) 한국고분자학회 2010 폴리머 Vol.34 No.5
조직공학에 이용되는 고분자인 poly(lactic-co-glycolic acid) (PLGA)는 높은 생체적합성 및 생분해성의 장점을 지니지만, 생체활성물질의 결여와 소수성으로 인해 세포의 부착에 어려움을 가진다. 또한 PLGA의 가수분해 과정 중 생성되는 산 분해물이 조직주변의 pH를 감소시켜 염증을 유발하는 단점을 가지고 있다. 따라서 이러한 단점을 보완하기 위한 방법으로 천연고분자인 케라틴을 첨가한 PLGA필름을 제작하였으며 조직공학적 디스크재생에 응용하기 위하여 케라틴/PLGA 복합체필름의 원통형 지지체를 제작하였다. 이 원통형 지지체의 내부는 케라틴/PLGA 필름을 말아서 사용하였으며 외부는 PLGA 다공성 지지체 링을 제작하여 사용하였다. 본 연구에서는 이 지지체에 섬유륜세포를 파종하여 PLGA 필름과 케라틴/PLGA 필름을 이용한 원통형 지지체에서의 세포의 부착 및 생존율을 비교하고 케라틴을 첨가한 지지체의 우수성을 확인하였으며 강도의 우수성 또한 확언하였다. 이 결과는 디스크재생을 위한 지지체의 연구에 유용한 정보를 제공할 것이다. We developed laminated cylindrical scaffolds composed of poly(lactide-co-glycolide) (PLGA) and keratin, and investigated their potential for tissue engineering and disk regeneration. The scaffold was designed to have two parts, i.e. inner cylinder and outer disk, to mimic a natural disk. The outer disk was composed of PLGA and the inner cylinder was prepared using PLGA film or PLGA/keratin hybrid film. In this study, we investigated the effects of keratin on the growth and proliferation of annulus fibrous(AF) cells in the cylindrical scaffolds. Scaffolds containing PLGA/keratin films showed a significantly higher cell proliferation and expression of collagen I and II than the counterpart with PLGA films. Keratin containing scaffolds also exhibited an excellent mechanical strength, demonstrating that keratin influences the proliferation of annulus fibrous cells. The results provide valuable information on PLGA/keratin films for tissue engineered disk regeneration.
DBP 스폰지와 DBP/PLGA 지지체에서의 인간 디스크세포 거동분석 비교
이선경(Seon Kyoung Lee),홍희경(Hee Kyung Hong),김수진(Su Jin Kim),김용기(Yong Ki Kim),송이슬(Yi Seul Song),하윤(Yoon Ha),이동원(Dong Won Lee),강길선(Gil Son Khang) 한국고분자학회 2010 폴리머 Vol.34 No.5
본 연구팀은 DBP를 함침시킨 물성이 서로 다른 스폰지와 PLGA 지지체를 제작한 후 세포 부착, 증식 및 형태 유지를 알아보기 위한 실험을 수행하였다. WST 분석법과 SEM 관찰을 통하여 스폰지에 비해서 PLGA 지지체에서의 세포의 증식이 활발한 것을 확인하였고, RT-PCR을 통해 디스크세포에서 특이적으로 발현하는 제2형 콜라겐과 어그리칸의 발현을 확인하였다. WST 결과, 세포 증식률은 DBP/PLGA 지지체가 DBP를 함침시킨 스폰지보다 세포 증식률이 높음을 확인하였다. 본 연구팀은 스폰지보다 PLGA 지지체가 인간디스크의 표현형 유지 및 중식에 있어서 긍정적인 영향을 미치는 것을 확인하였다. We fabricated sponge and poly(lactide-co-glycolide) (PLGA) scaffolds impregnated demi-neralized bone particle(DBP) (DBP/PLGA) and investigated proper condition to proliferation and phenotype maintenance of intervertebral disc(IVD) cells by comparison between DBP/PLGA scaffold and DBP sponge. DBP/PIGGA scaffolds were prepared by solvent casting/salt leaching. Human IVD cells were seeded in scaffolds of two types. Cell viability and proliferation according to scaffolds were analyzed by WST assay and SEM. RT-PCR was assessed to measure mRNA expression of aggrecan and type Ⅱ collagen of human IVD cells. In WST assay results, cell viability in scaffolds impregnated DBP/PLGA scaffold were higher than DBP sponge. We could observe that disc cell mRNA expressed better in DBP/PLGA scaffold than DBP sponge. We concluded that the using of DBP/PLGA in terms of scaffold fabrication for bio-disc with human IVD cells is helpful growth of disc cells maintenance of phenotypes.
히알루론산을 함유한 PLGA 지지체와 섬유륜세포를 이용한 디스크 재생
최진희 ( Jin Hee Choi ),김순희 ( Soon Hee Kim ),홍희경 ( Hee Kyung Hong ),김수진 ( Soo Jin Kim ),이선경 ( Seon Kyoung Lee ),김온유 ( On You Kim ),박종학 ( Jong Hak Park ),이종문 ( John M Rhee ),강길선 ( Gil Son Khang ) 한국조직공학·재생의학회 2009 조직공학과 재생의학 Vol.6 No.1
Tissue engineering strategies have the potential to improve upon current techniques for intervertebral disc repair. However, determining a suitable biomaterial scaffold for disc regeneration is difficult due to the complex fibrocartilaginous structure of the tissue. Poly(lactide-co-glycolide)(PLGA) has controllable biodegradability and good biocompatibility. hyaluronic acid(HA) called natural moisturizer can be used as biomaterials. In this study, we evaluated 3-dimensional HA loaded PLGA scaffold on proliferation and phenotype maintenance of annulus fibrosus cells. HA/PLGA scaffolds were prepared by emulsion freeze-drying method. Annulus fibrosus cells were seeded in HA/PLGA scaffold, and then cell viability and proliferation analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide(MTT) assay. Reverse transcription polymerase chain reaction(RT-PCR) was assessed to measure mRNA expression for type II collagen, aggrecan and glycosaminoglycan(GAG) quantity from annulus fibrosus cells in scaffolds. In MTT assay result, cell viability in HA/PLGA scaffolds were higher than PLGA scaffolds. In addition, annulus fibrosus strongly expressed their specific mRNA and produced well sGAG in HA/PLGA scaffold. This result indicates that HA/PLGA scaffold is useful for intervertebral disc regeneration.
KT114 상호 / 업종 검색 시스템에서의 사전 기반 통상명 검색 모듈의 설계 및 구현
신봉근(Bong Keun Shin),정희정(Hee Jung Chung),김종수(Jong Soo Kim),김명호(Myoung Ho Kim),유병규(Byung Kyu Yoo),유광일(Kwang Il Yoo),홍희경(Hee Kyoung Hong) 한국정보과학회 1998 한국정보과학회 학술발표논문집 Vol.25 No.2Ⅰ
KT114 상호/업종 검색 서비스에서는 데이터베이스 내의 동일한 개체에 대하여, 사용자가 입력한 상호명과 실제 데이터베이스에 저장된 상호명이 서로 다른 ‘통상명 검색 문제’가 존재한다. 이는 사용자가 인지하고 있는 상호명이 실제 상호명이 아니라, 해당 상호의 대표적인 상표 혹은 상품명 등인 경우 발생한다. 본 논문에서는 이러한 ‘통상명 검색 문제’의 해결을 위하여 실제 상호와 사용자 인지 상호 간의 관계를 정의한 사전에 기반을 둔 해결 방안을 제안한다. 대용량의 자료에 대한 빠른 검색을 요구하는 시스템 특성상 사전의 구축 방식은 매우 중요한 문제이다. 본 논문에서는 사전을 구축하는 두 가지 서로 다른 접근 방법으로, ‘DBMS 내부 구축 방식’과 ‘외부 사전 구축 방식’에 대하여 설명하고, 시스템 환경을 고려하여 두 접근 방법을 비교 및 분석한다.
연료첨가제 주입에 따른 승용차의 규제물질 배출특성 분석
정성운 ( Sung Woon Jung ),손지환 ( Ji Hwan Son ),홍희경 ( Hee Kyoung Hong ),성기재 ( Ki Jae Sung ),김정수 ( Jeong Soo Kim ),김정화 ( Joung Hwa Kim ) 한국분무공학회 2015 한국액체미립화학회지 Vol.20 No.4
This paper was designed to investigate emission characteristics of regulated pollutants (CO, HC, NOx and PM) from 134 diesel and gasoline passenger cars based on emission standards according to fuel additives. The experiments using chassis dynamometer were conducted under NEDC and CVS-75 modes. Comparison for fuel additive management and test between Korea, USA, EU and Japan, Korea was more strict than others. The fuel additives of this study was satisfied within fuel manufacturing standards. For with/without fuel additives according to diesel emission standards, NOx of EURO 4 and EURO 5 showed a relatively similar tendency. In the case of PM reduction rate, EURO 5 was over 20% increased than EURO 4.In the case of standard deviation/average ratio for gasoline vehicles, variation interval was big for LEV 23.3~58% and ULEV 31.6~56.4%. Following the imposition of stricter regulations (EURO 5 and ULEV), difference rate for standard deviation was big. Especially, in the case of diesel vehicles, difference rate for NOx 68% and PM 48% was most big. The results of present study will be of assistance in completing the legislative process and will provide basic data to set up emission standards for fuel additives in Korea.
대형경유자동차의 NO₂/NO<SUB>X</SUB> 비율과 NO<SUB>X</SUB> 배출특성에 관한 연구
정택호(Taek Ho Chung),김선문(Sun Moon Kim),문선희(Sun Hee Mun),홍희경(Hee Kyoung Hong),이승환(Seoung Hwan Lee),서석준(Seok Jun Seo),김정화(Joung Hwa Kim),정성운(Sung Woon Jung),김인구(In Gu Kim),이종철(Jong Chul Lee),이종태(Jong Tae 대한환경공학회 2019 대한환경공학회지 Vol.41 No.4
대형경유자동차에서 배출되는 NOx는 국내 NOx 배출량 중 높은 비율을 차지하고 있으며, NO₂는 인체에 유해하며 대기환경을 오염시키는 물질로 알려져 있다. 본 연구에서는 대형경유트럭과 대형경유버스에서 배출되는 NOx를 실시간으로 측정하였으며, 다양한 조건에 따른 NO₂/NOx 비율과 NOX 배출특성을 파악하였다. 실시간으로 NOx의 농도를 측정한 결과 NO와 NO₂의 농도는 높은 출력을 요구하는 가속구간에서 증가하는 것으로 나타났다. 시험모드별 대형트럭의 NOX 배출량은 WHVC>NIER 9>UDDS 순으로 낮은 평균속도에서 높게 배출되었다. 반면, 대형버스의 NOx 배출량은 평균속도가 증가할수록 높게 배출되는 것을 확인하였다. 엔진 상태에 따른 대형트럭과 버스의 NOX 배출량은 엔진 미가열조건에서 23%, 78% 높게 배출되었다. 대형트럭과 대형버스의 NO₂/NOx 비율은 엔진 가열조건에서 각각 0.7~1.0%, 7.7~7.8%로 확인되었다. 본 연구의 결과는 도로변대기측정망의 NO₂ 농도 산정을 위한 기초자료로 활용될 것으로 기대한다. NOx emitted from heavy-duty diesel vehicles has a high percentage of domestic emissions in Korea. It is known that the NO₂ emission was polluted the atmospheric environments and was harmful to humans. Therefore, investigation on NO₂//NOx Ratio and NOx Emission Characteristics of Heavy-Duty Diesel Vehicles were carried out. In this study, NOx emissions from heavy-duty trucks and buses were measured by chassis dynamometer for heavy-duty vehicle in real time. Also, NO₂/NOx ratio and NOx emission characteristics were analyzed by emission analyzer according to various conditions. It is revealed that NO and NO₂ concentrations were increased in the acceleration section from results of NOx concentration in real time. The NOx emissions of heavy-duty trucks in test mode was confirmed a high level in order the average speed, but NOx emissions of heavy-duty buses were increased as the average speed increased. The NO₂/NOx ratio of heavy duty trucks and buses was 0.7~1.0% and 7.7~7.8% at hot start engine condition. The results of this study will contribute to be used as basic data for the estimation of NO₂ concentration in the roadside air monitoring network.