Differential Antiproliferative Responses of Green Tea Polyphenol for Fibroblast Cell Line versus Normal Fibroblast

The polyphenolic compounds present in green tea show antimutagenic, anti-inflammatory and antitumorigenic effects in many cell culture systems and animal tumor models. Epidemiologic studies have also suggested that green tea consumption might be effective in the prevention of certain human cancers. In this study, the differential antiproliferative responses of green tea polyphenols (GTP) were investigated in fibroblast cell line (L-929 cells, from mouse connective tissue) and normal fibroblasts (from neonatal human dermis). GTP treatment (100 μM for 24 h) resulted in significant (p < 0.05) inhibition of cell proliferation and morphological alterations with decreased local attachment, but not in normal fibroblasts. Cell cycle analysis revealed that the GTP treatment resulted in an appreciable G0/G1-phase arrest of the cell cycle in L-929 cells at 100 μM concentration, while under similar experimental conditions, no evidence of G0/G1-phase cell cycle arrest was found in normal fibroblasts at the same dose. These results suggest that antiproliferative activity of GTP may be attributed to the differential regulation of cell cycle in fibroblast cell line and normal fibroblasts, which GTP may be exploited to craft strategies for the chemoprevention and/or therapy against cancer by GTP.ope

펜타플루오로페닐 아크릴레이트 고분자를 기반으로 한 생체분자 고정용 플랫폼의 제조

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 화학생물공학부, 2018. 8. 차국헌.Functional polymers have had attention and been expected as a promising materials in a wide range of application fields such as biotechnology, photonics, and optoelectronics, and biocompatibility. The physical or chemical properties and nanostructures constituted of functional polymer should be controlled by diverse synthesis and processing methods. As more complicated platforms based on functional polymers required, reactive ester polymers were utilized for both preparation of novel polymeric precursors and for the fabrication of reactive polymer-based platforms with desired functionalities and forms. The controlled radical polymerization techniques were utilized to yield in well-defined polymers and polymer-based films and brushes. Furthermore, modification of reactive polymer platforms results in facile approaches to bio-applications by covalent immobilization of biomolecules. In this thesis, poly(pentafluorophenyl acrylate) (poly(PFPA)), one of active ester polymers, was realized in the structures of thin films and polymer brushes and considered as biomolecule immobilization platforms through post-polymerization modification methods using its high reactivity with amines. The brief introduce about reactive polymer and synthesis methods and biomolecule immobilization are in chapter 1. In chapter 2, we investigate the mechanism in primary amine-induced post-polymerization modification of spin-cast active ester polymer thin films, comprised of poly(PFPA). The most important physical parameters in the post-modification are the molecular weight of PFPA polymers and the aliphatic chain length of primary amines. The effect of two parameters on the penetration depth as well as the exchange kinetics was systematically studied by neutron reflectivity (NR) and quartz crystal microbalance (QCM-D), accompanied by the surface morphological changes measured by an atomic force microscope (AFM) and an optical microscope (OM). The spin-cast thin films of high and low molecular weight of poly(PFPA) showed the distinctive difference originating from the primary alkyl amines of different alkyl chain length. The aliphatic chain length of primary alkyl amines dramatically influenced the penetration kinetics into low molecular weight poly(PFPA) films whereas there was no significant penetration effect on the high molecular weight films. The high molecular weight of poly(PFPA) films led to the deceleration of dissolution of amine-functionalized polymer chains in good solvent. Both alkyl chain length of primary alkyl amines and the molecular weight of poly(PFPA) affect the penetration depth and dissolution of the polymer chains from the surface of thin films, respectively. In chapter 3, we present the synthesis of reactive polymer brushes prepared by surface-initiated (SI) RAFT polymerization of pentafluorophenyl acrylate. Dithiobenzoic acid benzyl-(4-ethyltrimethoxylsilyl) ester was used as the surface-initiated RAFT chain transfer agent (SI-CTA) and the anchoring group onto the silica particles. Poly(pentafluorophenyl acrylate) (poly(PFPA)) is known to have high and selective reactivity with amine functional groups that offers facile routes to realize diverse functions starting from the same platforms by simple post-polymerization modification with amines. Through the grafting-from approach, polymer brushes with controlled molecular weight and conformal coverage were obtained. The synthesis and utilization of reactive polymer brushes offers an easy approach in the controlled-fabrication of polymer brushes with desired functionality, which is limited by other strategies. In chapter 4, we reported the poly(PFPA) brush-based platforms for antibody-antigen precipitation or immunoprecipitation (IP), which are routinely performed by biologists to isolate specific antigens and to identify their interactors from complex protein mixtures. The conventional approach involving agarose supports shows reasonably good antibody-binding capability due to their selective bioaffinity immobilization, but often suffers from high nonspecific binding and antibody contamination. We prepared silica particles containing poly(PFPA) brushes, prepared by the reversible addition-fragmentation chain transfer (SI-RAFT) polymerization. Upon sequential functionalization with antibodies and polyethylene glycol (PEG), it showed significantly reduced nonspecific protein adsorption and complete elimination of antibody contamination. Furthermore, by optimizing the two parameters such as molecular weight of the polymer brushes and the amount of PEG passivates, the poly(PFPA) brush-grafted particles show the highest efficiency. Taking into account their versatility and convenient features of such reactive brush platforms, the poly(PFPA) platforms have the potential to be an alternative to traditional agarose-based platforms for immunoprecipitation. In chapter 5, we briefly introduced about poly(PFPA)-coated channel for the application of biosensors. Substrates which have amine functional groups on the surface were coated with poly(PFPA) as loop or train configuration of grafted brushes. To get more stability of poly(PFPA) films during incubation process in antibody solution, many conditions were tested and characterized by confocal images. Some functional groups in poly(PFPA) chains reacted with amine groups on substrates and the other remained groups were used for immobilization of fluorescent antibodies. Based on the fabrication of channel on the poly(PFPA)-coated substrates, we expected this simply fabricated poly(PFPA)-based platforms can be applied as biosensor for primary diagnosis. In conclusion, reactive poly(PFPA) platforms that allow facile preparation of functional material was demonstrated from polymer films to polymer brush particles. The reactive poly(PFPA) thin films and particles based on the simple and quantitative post-modification with amine-containing molecules could be utilized for many practical applications due to the ease of control over the degree of functionalization. Our system and the strategy would provide a facile process towards functional polymer film, and polymer brushes by eliminating difficult multistep of synthesis. Furthermore, the possibility of poly(PFPA)-based platforms for the use in bioapplications such as purification and biosensing was confirmed.Chapter 1. Introduction 1 1.1. Functional Polymers 1 1.2. Biomolecule Immobilization in Bio-applications 4 1.3. Active Ester Monomers and Their Polymers as Precursors for Functional Polymeric Platforms 6 Chapter 2. Reactive Polymeric Platforms Based on Poly(Pentafluorophenyl Acrylate) Polymers 10 2.1. Introduction 10 2.2. Experimental Section 13 2.3. Results and Discussion 17 2.3.1. Post-Modification of Poly(PFPA) Thin Films with Primary Alkyl Amines 17 2.3.2. Effect of Aliphatic Chain Length of Primary Alkyl Amines on the Exchange Kinetics of Poly(PFPA) Films 22 2.3.3. Effect of Molecular Weight of Poly(PFPA) Chains on the Dissolution of Poly(PFPA) Thin Films Post-Treated with Primary Amines 29 2.3.4. NR Studies on the Amine-Exchange Kinetics of Poly(PFPA) Films 42 2.4. Conclusion 44 Chapter 3. Preparation of Poly(Pentafluorophenyl Acrylate) Brush-Grafted on Silica Particles 46 3.1. Introduction 46 3.2. Experimental Section 49 3.3. Results and Discussion 52 3.3.1. Surface-Initiated RAFT Polymerization of Poly(PFPA) Brushes 52 3.3.2. Polymerization of Polymer Brushes in Different Molecular Weights 58 3.3.3. Grafting Density of Polymer Brushes on SiPs 63 3.4. Conclusion 67 Chapter 4. Reactive Polymer Brush-Grafted Particles for Immunoprecipitation 68 4.1. Introduction 68 4.2. Experimental Section 71 4.3. Results and Discussion 74 4.3.1. Post-Treatment of Polymer Brushes with Amino-Terminated PEGs 74 4.3.2. Molecular Weight Effect on the Poly(PFPA) Brushes Used for Immunoprecipitation 86 4.3.3. Post-Modification of Poly(PFPA) Brush-Grafted Particles with Different PEG-Amines for Immunoprecipitation 89 4.4. Conclusion 92 Chapter 5. Reactive Polymer-Based Platforms for Biosensing Applications 94 5.1. Introduction 94 5.2. Experimental Section 96 5.3. Results and Discussion 99 5.3.1. Fabrication of Poly(PFPA) Film Based on APTES Coating 99 5.3.2. Fabrication of Poly(PFPA)-Coated PDMS Channels for Biosensor Application 106 5.4. Conclusion 108 References 109 국문 초록 119Docto

Reading Frankenstein in terms of Modern Prometheus and the Female Creative Power

메리 셸리의 소설 는 서구 문명이 산업사회로 접어들던 시기에 탄생한 현대의 악몽이다. 본 논문은 이 소설의 부제인 모던 프로메테우스에 초점을 맞추어 읽어보려한다. 낭만주의 시인들은 프로메테우스를 사회적 정신적 자유를 위해 투쟁하는 불굴의 인간정신과 무한한 상상력의 상징으로 삼았다. 그렇다면 과 연 셸리가 제시하는 모던 프로메테우스는 어떤 인물인가? 소설 속 프랑켄슈타인은 과학과 지성의 힘으로 실험실에서 인간을 창조하려 시도하고 반면에 여성 셸리는 남성의 전유물로 여겨졌던 글쓰기, 그것도 과학적 지식에 입각한 공상과학소설을 시도한다. 전통적인 성 역할을 전복시킴으로써 셸리는 폴 영퀴스트가 지적했듯이, 자신의 어머니이자 여성운동의 선구자였던 메리 울스턴크래프트의 여성권리 옹호에 이은 여성의 상상력 옹호를 주창하고 있다고 볼 수 있다. 흥미롭게도 셸리는 프랑켄슈타인의 생명창조과정을 당시 부인과 의학서의 임신 출산에 대한 담론의 언어를 빌어 묘사하고 있는데 이는 자신이 경험한 임신과 출산을 둘러싼 자전적 요소들과 함께 작품전체를 아우르는 셸리 특유의 언어를 지지해주는 틀을 구성한다. 본 논문은 18세기 당시의 임신 출산과 관련된 산부인과 관련 담론들을 살펴보고, 셸리가 프랑켄슈타인의 인간창조과정을 묘사하는데 이러한 언어를 (의식적이든 무의식적이든) 어떻게 사용하고 있는지 검토해 본다. 그리고 18세기 영국의 임신과 출산에 관한 의학적 담론을 바탕으로 당시 사회의 임신 출산에 관한 시각을 알아보고, 그러한 시각을 통해 프랑켄슈타인의 프로메테우스적 과업과 셸리 자신의 소설 창작과정을 함께 조명하여 셸리가 생각했던 모던 프로메테우스의 모습을 찾아보고자 한다.Mary Shelleys Frankenstein, Or The Modern Prometheus is a depiction of a haunting nightmare of Western civilization since the dawn of the modern industrial society. This paper will be reading the novel, focused on its subtitle, The Modern Prometheus. Invoking the myth of Prometheus who was taken for the symbol for the unvanquished human willpower and the overreaching pursuit beyond the human limitations by Romantic poets, Shelley asks us what the Modern Prometheus should be. By assigning to a man the job of creating life with the supreme knowledge while to herself that of giving birth to a book instead of a child, Shelley subverts the established gender roles. As a result Victor Frankenstein ended up creating a monstrous creature who eventually destroyed its creator and itself, while Shelley succeeded in writing the novel, Frankenstein, which Paul Youngquist calls a Vindication to the Imagination of Women, a sequel to her mother, Mary Wollstonecrafts The Vindication to the Right of Women. The novel is about giving birth, which is a power unique to the woman and the core of natures secret and the goal of Frankensteins aspiration. In this nightmarish story, Shelley tries to demolish and deconstruct the binary oppositions between masculine and feminine, life and death, and civilization and nature. The birth of the monster is the first step to our recognition of the problems involving the exploitation of the nature in the name of science and civilization.이 논문은 2007년 정부(교육과학기술부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(NRF-2007-361-AL0016)

인간 발달 과정 내 체성 모자이크 현상의 특성 분석

Somatic mosaic variants during human development remain elusive despite advanced genetic technology. Most published studies have crucial issues: postmortem brain tissue does not always accompany with peripheral tissues as matched control and could not accurately classified by their occurrence timing. divided mosaic mutations into their occurrence timing. We performed deep whole exome sequencing (average read depth ~500x) and systematic analysis of both brain and matched peripheral tissues for 498 samples from 190 individuals. We classified somatic mutations according to when they occurred during the early- or late-stage mutations of human development by whether sharing the mutations derived two different germ-layer tissues. We identified average 0.54 mosaic variants per individual with an average variant allele frequency (VAF) of 6.17% during early embryonic development compared with average 5.83 somatic variants per individual a VAF of 1.5% during late embryonic development and the post-natal period. Each of the early- and late-stage mutations has a distinct mutational signature compared to tumor-originated mutations. Their functional aspect also showed a clear difference, which was supported by their biological process. Subgroup analysis of late-stage mutations revealed average 0.77 brain somatic variants with high VAF (average 7.32%) and showed their genomic characteristics clustering with properties of early-stage mutations which indicates that brain somatic mutations were acquired relatively early in the embryonic period; and tumor-originated mutations which are speculated to be influenced by a neurogenic niche of the temporal lobe. Despite a limited sample size and observation of only the exonic area, we provide a systematic analysis of the early embryonic and late developmental somatic mosaic mutations of the brain and their biological and genetic implications. 최근 유전학 기술의 엄청난 발전과 시퀀싱 기술의 발달로 그동안 밝혀내지 못했던 다양한 질환과 유전변이의 관계가 밝혀지고 있다. 그럼에도 인간의 발생 초기 또는 뇌의 발달 중에 생기는 체성 돌연변이와 이들의 모자이크 현상은 연구자들에게 여전히 도전적인 과제다. 살아있는 사람에게서 뇌 조직을 직접 얻기가 매우 어려울 뿐 아니라 암 유전체 연구와 같이 대조군을 함께 시퀀싱하는 일이 드물기 때문이다. 본 연구에서는 190명의 개인으로부터 498개의 뇌 및 말초 조직을 각각 1쌍 또는 그 이상 취득하여 매우 높은 깊이의 전장 엑솜 시퀀싱(평균 깊이 ~500x)을 실시한 후, 체계적인 분석을 시행하였다. 특히, 체성 모자이크 현상에 대한 깊은 고찰 및 검토를 통해, 체성 돌연변이를 인간 발생 또는 뇌 발달의 초기 단계에서 발생한 변이와 발생의 후기 단계 또는 출생 이후에 발생한 변이로 각각 분류하고, 검출함으로써, 이들이 가지는 특징을 살펴보았다. 발생의 매우 이른 시기에 발생한 체성 돌연변이는 한 개인당 0.54개, 평균 6.17%의 VAF 수준으로 존재하고 있음을 확인했다. 이는 발생 후기 또는 출생 이후에 발생한 체성 돌연변이들이 한 개인당 5.83개와 평균 1.5%의 VAF로 관찰된다는 사실과 매우 두드러지게 구별된다. 또한, 그들의 생성 과정을 짐작할 수 있는 변이 시그니처 양상과 기능적인 측면 역시 분명한 차이를 나타냈다. 이것은 발생생물학적 관점과도 일치하는 부분으로, 실증적인 수치 및 통계적 유의성을 제시할 수 있는 매우 신뢰도 높은 결과이다. 한편, 발생 후기 또는 출생 이후에 발생한 변이 중, 뇌에서만 검출된 변이는 발생 초기 단계에서 생성된 변이와 매우 유사하게 개인당 평균 0.77개의 모자이크 변이와 높은 VAF값인 7.32%를 가지는 것을 확인했다. 이들의 변이 시그니처는 발생 초기 단계 변이와 종양 기원 돌연변이의 특징을 함께 나타낸다. 전자는 뇌 특이적인 변이가 상대적으로 뇌 발달의 초기 단계에 발생했음을 암시하며, 후자는 측두엽에서의 신경 생성이 반영된 결과로 추정된다. 엑솜에 한정된 샘플의 구성 및 분석을 실시했음에도 본 연구는 단일 세포 시퀀싱과 같이 고도의, 값비싼 시퀀싱 기술을 활용하지 않고도 매우 정확한 수준으로 체성 돌연변이를 찾고, 이들을 생성 시기에 맞추어 분류했다. 특히, 조직 내 일부 클론 또는 단일 세포 수준이 아닌 실질적인 이형성에 기여하는 모자이크 변이에 대한 특징을 분석 및 제시할 수 있었다는 점에서 시사하는 바가 크다. 이번 연구는 체성 모자이크 변이의 관점을 체내 단일 조직이 아닌 여러 조직 수준으로 확장하며 이에 대한 생물학적, 유전학적 의미를 제공하여, 향후 다양한 분야의 체성 변이 연구에 적절한 지표로 활용될 수 있을 것으로 기대된다.open박

The Experience of Modern Tourism in the Diary of Apo

본 논문은 1969년부터 2000년까지의 급속한 산업화 기간 동안 에서 나타난 농민 권순덕의 근대적 관광 경험의 특징을 살펴보기 위하여 노동과 관광의 개념, 관광활동의 구체적인 내용, 그리고 관광활동에서 드러난 양가성을 고찰하였다. 권순덕은 노동중심의 가치관에 근거하여 여가는 낭비적인 일로 여기고 관광은 여러 곳의 장소를 방문하는 것으로 인식하여 자연경관과 문화유적지 중심의 관광을 한다. 권순덕이 경험한 관광활동의 특징은 단체관광에서 개인관광 및 체험중심의 관광으로 변화를 보여 주고 있고, 가족여행과 해외여행 경험이 없으며, 공동체 연대를 증진시키는 통합적 기능이 강하였다. 권순덕에게 관광은 관광절차의 합리화와 객관화된 성적 욕망이 공존하는 양가성을 노출한다. 권순덕의 여행 전체를 살펴볼 때 여행과 관련된 자원도 풍성해지고, 여행횟수도 늘고 기간도 길어지지만 개인의 삶을 뒤돌아보고 성찰할 수 있는 진정한 의미의 개인 여행이 부족하였다, 마지막으로 본 논문의 의의는 그동안 소홀하였던 농민 관광의 특징을 밝혀낼 수 있었다는 것이다.This paper examines the ways in which a Korean farmer underwent modern tourism, focusing on the concept of labor and tourism, tourist activities, and ambivalence, from 1969-2000 during the rapid industrialization process in the Diary of Apo. Gwon Sun-Deok, who is an author of the Diary of Apo, considered leisure as an useless activity based on his labor-centered perspective. His definition of tourism is focused on visiting attractive places rather than authenticity of the tourist experiences. In the modern tourism of Gwon Sun-Deok, two main features are identified: (1) Gwons mass tourim practices slowly changed to small group tour and experience tourism, (2) He had no experience of family trip and overseas travel, and his tourism emphasized the integral role of tourism for the rural community. The apparent manifestation of ambivalence in Gwons tourism practice comes from the conflict between the rationalization of tourism process and objectified sexuality in the tourist site. In the general sense, on the one hand, his tourism experienced continued growth and deepening diversification, on the other hand, it revealed the lack of real meaning of tourism due to the lack of understanding of history and culture of tourist sites

Post-Modification of Reactive PPFPA Thin Films Using Primary Alkyl Amines

학위논문 (석사)-- 서울대학교 대학원 : 화학생물공학부, 2014. 2. 차국헌.In this paper, we investigate the controlled post-modification of spin-cast reactive polymer thin films, based on pentafluorophenyl acrylate polymers, with two controlling parameters such as molecular weight of the bare polymer and the size of amines. Active ester polymers have begun to demonstrate its potentials due to its rapid and quantitative reactivity with primary or secondary amines. Diverse chemical properties of amine-containing molecules could be transferred into the poly(PFPA) platforms easily. The spin-cast thin films of high and low molecular weight of poly(PFPA), synthesized by the reversible addition-fragmentation chain transfer (RAFT) polymerization, showed the distinctive difference originating from the primary alkyl amines of different alkyl chain length. We monitored the amine-exchange kinetics and the penetration depth into poly(PFPA) thin films using quartz crystal microbalance with dissipation (QCM-D), combined with the surface morphological changes using AFM and OM. For further investigation of the internal structure of post-treated films, neutron reflectivity measurements were conducted. In conclusion, both alkyl chain length of primary alkyl amines and the molecular weight of poly(PFPA) affect the penetration depth and dissolution of the polymer chains from the surface of thin films, respectively. The reactive poly(PFPA) thin films based on the simple and quantitative post-modification with amine-containing molecules could be utilized for many practical applications due to the ease of control over the degree of functionalization and film properties.Chapter 1. Introduction 1 Chapter 2. Experimental 4 2.1. Materials 4 2.2. Synthesis of Pentafluorophenyl Acrylate 4 2.3. Synthesis of Benzyl Dithiobenzoate (BDTB) 4 2.4. Poly(PFPA) via RAFT Polymerization 5 2.5. Sample Preparation 5 2.6. Characterization 6 Chapter 3. Results and Discussion 8 3.1. Preparation and Post-Modification of Poly(PFPA) Spin-Cast Films 8 3.2. The Effect of Alkyl Chain Length of Primary Alkyl Amines on the Reactivity of Poly(PFPA) Thin Films 11 3.3. The Effect of Molecular Weight of Poly(PFPA) Chains on the Dissolution of PFPA Thin Films Post-Treated with Primary Amines 17 3.3.1. Amylamine Treatment on the Poly(PFPA) Films 17 3.3.2. Dodecylamine Treatment on the Poly(PFPA) Films 23 3.4. NR Study on the Amine Exchange Kinetics of Poly(PFPA) Films 27 Chapter 4. Conclusion 30 References 31Maste

소금물의 전기분해로 생성된 산화제의 화학적 특성과 소독효과 연구

학위논문(석사)--서울대학교 대학원 :응용화학부,2003.Maste

(1→3),(1→6)-β-D-Glucan의 창상 치유에 대한 효과

Dept. of Medical Science/석사[한글] 베타 글루칸은 다당류의 천연 물질로서, 면역 반응을 증가시키고 특히 창상 치유에 효과가 있는 것으로 알려져 왔다. 베타 글루칸의 창상 치유 효과와 관련하여 직접 또는 간접적인 경로의 두 가지 메커니즘이 제시될 수 있다. 그 첫 번째는 베타 글루칸이 섬유아세포의 표면에 존재하는 수용체를 통하여 세포가 이동하고 증식하도록 직접적으로 신호를 보낸다는 가설이다. 이미 베타 글루칸의 수용체가 포유류의 대식세포와 같은 단핵 세포 외에 사람의 진피 세포에도 적어도 둘 이상의 결합 부위를 갖고 있다는 사실이 보고 된 바 있다. 두 번째 가설은, 창상 이후 처리된 베타 글루칸이 대식세포를 자극하여 몇몇 사이토카인과 성장 인자를 분비하도록 하고, 이들이 섬유아세포가 창상 부위로 이동하고 증식하도록 신호한다는 가설이다. 대식세포로부터 분비되는 사이토카인과 성장 인자 중 TNF-α와 IL-6와 같은 염증 관련 사이토카인이나 TGF-β는 특히 창상 치유 과정에서 섬유아세포의 활동과 밀접한 관련이 있다. 이 연구에서는 (1→3),(1→6) 베타 글루칸이 창상 치유 과정 중 섬유아세포에 미치는 직, 간접적인 영향을 생체 내 그리고 생체 밖 실험을 통하여 평가하고자 하였다.섬유아세포의 증식과 이동 시험의 결과에서 (1→3),(1→6) 베타 글루칸은 사람의 성인 진피세포의 이동에는 효과를 갖지만, 증식에는 효과를 갖지 않았다. 또한 베타 글루칸은 대식세포를 활성화시켜 TNF-α와 TGF-β1의 분비량을 증가시켰으나, IL-6의 양은 증가시키지 않았다. TNF-α는 섬유아세포의 증식을 활성화시키고 콜라겐 합성을 자극하는 것으로 알려져 있다. 그리고 TGF-β1는 창상치유 과정에서 섬유아세포의 증식 및 이동과 세포외 기질의 생성을 증진시킨다. 따라서 이 결과는 베타 글루칸이 대식세포에 의한 사이토카인의 분비를 증가시킴으로써 창상치유에 영향을 미칠 수 있다고 제시한다. 생체 내 창상 치유 시험의 결과 베타 글루칸을 처리한 창상이 식염수나 콜라겐을 처리한 창상보다 빠른 수축을 보였다. 이러한 결과는 (1→3), (1→6) 베타 글루칸의 적용이 창상 치유를 증진하는데 유용하다는 것을 의미한다.결론적으로, 이러한 일련의 결과들은 (1→3), (1→6) 베타 글루칸이 직, 간접적인 경로 모두를 통해 섬유아세포를 활성화시킴으로써 창상치유에 효과가 있음을 제시한다. [영문]β-Glucan is a natural product of glucose polymer, which has immune stimulatory activity, especially effective on wound healing. Relating with wound healing activity of β-glucan, two major mechanisms can be hypothesized as direct and indirect pathways. First hypothesis is that β-glucan directly signals fibroblasts to migrate and proliferate, through their receptors on fibroblasts. It was already reported that there are at least two β-glucan binding sites on normal human dermal fibroblasts other than immunocytes such as mammalian macrophage. Second hypothesis is that β-glucan, treated after the occurrence of wound, activates macrophages to release some cytokines and growth factors, which signal fibroblasts to migrate into wound sites and proliferate. Among those cytokines and growth factors secreted from macrophages, pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) or transforming growth factor-β (TGF-β) are especially related with fibroblast activities in wound healing. In the present study, we evaluated the direct and indirect effects of (1→3),(1→6)-β-D-glucan on fibroblast for wound healing process through in vitro and also in vivo tests.The results of fibroblast proliferation and migration assay showed that (1→3),(1→6)-β-D-glucan have effect on the migration of adult human dermal fibroblasts, but no positive effect on proliferation. And β-glucan activated macrophages to upregulate the TNF-α and TGF-β1 secretion, but no significant difference was shown in the amount of IL-6. TNF-α is known to be mitogenic for fibroblasts and stimulate collagen biosynthesis. And TGF-β1 stimulates fibroblasts to proliferate, migrate and promote production of ECM during wound healing. These results suggested that β-glucan have effect on wound healing through cytokines and growth factor production by macrophages. In the result of in vivo wound healing assay, β-glucan treated wounds showed the faster contraction than saline or collagen treated wounds. This result means that topical administration of (1→3),(1→6)-β-D-glucan was useful to promote wound healing.In conclusion, these results suggest that (1→3),(1→6)-β-D-glucan could be helpful to wound healing by fibroblast activation through both direct and indirect pathways.ope

Iridium Oxide as a Stimulating Neural Electrode Formed by Reactive Magnetron Sputtering

Implantable neural prostheses form hybrid interfaces with biological constructs, and the application of electrical fields can restore functions of patients with neurological damages. The various stoichiometric compositions of iridium oxide were synthesized using reactive magnetron sputtering. The charge injection behavior of iridium oxide deposited with an O2/Ar ratio of 0.5 was similar to pure Ir. The charge density of iridium oxide increased with increasing O2/Ar ratio, and increasing thickness of iridium oxide.ope