견 피브로인 나노섬유의 제조 및 특성분석 = Preparation and Characterization of Silk Fibroin Nanofibers

다국어 초록 (Multilingual Abstract)

Recently, much attention has been paid to electrospinning process as a unique technique because it can produce polymer nanofibers with diameter in the range from several micrometer down to tens of nanometers, depending on the polymer and processing conditions. In electrospinning, a high voltage is applied to create electrically charged jets of a polymer solution. These jets dry to form nanofibers, which are collected on a target as a nonwoven fabric. These nanofibers are of considerable interest for various kinds of applications, because they have several useful properties such as high specific surface area and high porosity. Examples are fiber membranes for filter applications, biomedical applications such as wound dressings and scaffolds for tissue engineering, sensing applications. An electrospinning process was used to fabricate silk fibroin (SF) nanofiber nonwovens for wound dressing applications. The electrospinning of regenerated SF was performed with formic acid as a spinning solvent. For crystallization, as-spun SF nanofiber nonwovens were chemically treated with an aqueous methanol solution of 50%. The morphology, porosity and conformational structures of as-spun and chemically treated SF nanofibers were investigated by scanning electron microscopy (SEM), mercury porosimetry, wide angle X-ray diffraction (WAXD), attenuated total reflectance infrared spectroscopy,(ATR-IR), solid-state ^(13)C CP/MAS nuclear magnetic resonance (NMR) spectroscopy, SEM micrograph showed that the electrospun SF nanofibers had an average diameter of 80nm and a distribution in diameter ranging from 30 to 120nm. The porosity of as-spun SF nanofiber nonwovens was 75.1 %, indicating it was highly porous. During the chemical treatment for 60 min, porosity of nonwovens composed of SF nanofibers decreased of to 68.1%. Conformational transitions of the as-spun SF nanofibers from random coil to β -sheet by aqueous methanol treatment occurred rapidly within 10 min, confirmed by solid-state ^(13)C CP/MAS NMR, ATR-IR and X-ray diffraction. To assay the cytocompatibility and cell behavior onto the electrospun SF nanofibers, cell attachment of norma1 human keratinocytes seeded on the SF nanofibers and interaction between cells and SF nanofibers were studied. Cell morphology on SF nanofibers was examined by scanning electron microscopy. Our results indicate that the SF nanofibers may be a good candidate for the biomedical applications, such as wound dressing and scaffolds for tissue engineering.

목차 (Table of Contents)

• 목차 = ⅰ
• List of Figures = ⅳ
• List of Tables = ⅶ
• Ⅰ. 서론 = 1
• Ⅱ. 이론적 배경 = 4
• 2.1. 견의 개요 = 4
• 2.1.1. 고치실의 구조 = 5
• 2.1.2. 견의 아미노산 조성과 화학구조 = 7
• 2.1.3. 견 피브로인의 응용 = 10
• 2.2.전기방사의 개요 = 12
• 2.2.1. 전기방사의 역사 = 15
• 2.2.2. 전기방사의 원리 = 16
• 2.2.3. 전기방사의 조건 = 19
• 2.2.4. 전기함사의 특성 = 20
• 2.2.5. 전기방사된 초극세 섬유의 활웅 = 23
• Ⅲ. 실험 = 24
• 3.1. 견 피브로인의 재생과 방사용액의 제조 = 24
• 3.2. 견 피브로인/포름산 용액의 전기 방사 = 27
• 3.3. 견 피브로인 나노섬유의 특성 분석 = 29
• 3.3.1. 견 피브로인/포름산 용액의 점도 측정 = 29
• 3.3.2. 방사된 견 피브로인 나노섬유의 형태학적 특성 분석 = 29
• 3.3.3. 견 피브로인 나노섬유의 2차 구조 분석 = 29
• 3.3.4. 견 피브로인 나노섬유의 기공 특성 분석 = 30
• 3.3.5. 견 피브로인 나노 섬유의 인장 특성 분석 = 30
• 3.4. 견 피브로인 나노섬유의 세포 점착 및 배양 실험 = 32
• Ⅳ. 실험 결과 및 고찰 = 34
• 4.1. 견 피브로인/포름산 용액의 점도 특성 = 34
• 4.2. 견 피브로인 나노섬유의 전기방사에 대한 농도 및 점도 효과 = 36
• 4.3. 견 피브로인 전기방사에 있어서의 공정인자의 영향 = 40
• 4.3.1. 방사 전압의 영향 = 40
• 4.3.2. 집적 거리의 영항 = 43
• 4.3.3. 용액 농도의 영향 = 46
• 4.3.4. 방사구 크기의 영향 = 49
• 4.3.5. 용액 유출량의 영향 = 54
• 4.4. 견 피브로인 나노섬유로 이루어진 부직포의 제조 = 58
• 4.5. 전기방사된 견 피브로인 나노섬유의 2차 구조 = 61
• 4.5.1. 표면 반사 적외선 분광 분석 = 63
• 4.5.2. X선 회절 패턴 분석 = 65
• 4.5.3. 핵 자기 공명 분광 분석 = 67
• 4.6. 견 피브로인 나노섬유의 기공 특성 = 73
• 4.7. 견 피브로인 나노섬유의 인장 특성 = 76
• 4.8. 견 피브로인 나노섬유의 세포 점착 및 배양능 결과 = 80
• Ⅴ. 결론 = 84
• Reference = 86
• ABSTRACT = 93