이 연구는 NASA의 우주 네브래스카 그랜트 기금 번호 0,926,880 미만의 국립 과학 재단 (National Science Foundation)에 의해 부분적으로 지원되었다.

1. 라텍스 선박의 작성 <ol><li> 견고한 작업대에 고정되는 가시 호스 연결에 라텍스 선박의 양쪽을 고정한다. </li><li> 보기의 필드를 결정하기 위해 라텍스 선박에 대한 관심의 영역을 측정합니다. 스텐 트 테스트에 대한 관심의 영역은 가시 호스 커넥터 사이의 중심과 stented 지역 밖의 변종을 관찰하기 위해 스텐 트의 각 측면에 약 1 인치 포함되어야합니다. </li><li> 한 가시 호스 커넥터의 외부 가장자리에서 또한 라텍스 선박의 대략적인 중심 커넥터 사이의 중앙 위치에 거리를 기록합니다. 카테터 최대 스텐 트의 중심에서 측정하여 카테터에 거리를 번역. 그런 다음 마커로 카테터를 표시합니다. </li><li> 가시 호스 커넥터에서 라텍스 혈관을 제거합니다. </li><li> 흰색과 검정색 스프레이 페인트의 확률적 패턴으로 관심 영역을 분사하거나 표시하여 라텍스 용기 준비영구 마커를 사용하여 임의의 점들과 관심 영역입니다. 들어 작은 샘플 및 미세한 확률 패턴이 필요합니다. </li></ol> 아라미스 시스템의 2.에서 체외 테스트 시스템 및 보정 <ol><li> 1 단계에서 측정한 관심 영역보다 약간 큰 보정 패널을 선택합니다. </li><li> 관심 영역에서 가시 호스 커넥터 간의 보정 패널을 놓고 관심 영역이 잘 점등되었는지 확인합니다. </li><li> 카메라 두 대, 시료의 거리, 그리고 선택된 보정 패널을 기반으로 카메라의 높이 사이의 거리를 조정합니다. 각 교정 패널은 다른이므로 아라미스 사용자 설명서는 이러한 거리를 결정하기 위해 상담을해야합니다. </li><li> &quot;새 프로젝트&quot;다음 &quot;파일&quot;을 선택하여 아라미스에서 새 프로젝트를 엽니다. 다음의 &#39;센서&#39;탭을 클릭한 후, &quot;전체 보정을&quot; &quot;보정&quot;을 선택하십시오. </li><li> 아라미스 소프트웨어는 이제 T를 보정하는 단계를 통해 사용자를 안내합니다<html> 그는 카메라. </li><li> 완전히 열린 렌즈 조리개를 통해 카메라에 세트 나사를 풀어과 렌즈를 회전하여 보정 패널에 카메라 초점을 맞춥니다. 일단 초점을 맞추고, 세트 나사를 retighten하고 조리개를 닫습니다. </li><li> 교정 프로세스의 첫 번째 이미지를 가져가라. 치환이나 이미지가 컴퓨터 화면에 초점이 맞추 어져 때까지 컴퓨터의 시연에 따라 보정 패널을 돌린다. 두 번째 이미지를 가져가라. 보정 이미지의 나머지 부분에 대해이 과정을 반복합니다. </li><li> 일단 보정 이미지를 모두 촬영하고, 아라미스 이미징 분석 소프트웨어 보정 설정을 계산합니다. 교정 편차가 0.04보다 큰 경우에는 보정 과정은 반복되어야한다. 카메라 또는 카메라 사이의 거리의 초점에 적용한 모든 조정은 교정 프로세스 무효를 렌더링합니다. </li><li> 보정 패널을 제거하고 가시 호스 커넥터에 다시 도장 라텍스 용기를 놓습니다. </li></ol>과도한 배경 잡음을 피하기 위해 제목 &quot;&gt; 3. Pretest <ol><li> 시험을 원하는되는 초당 프레임의 개수를 결정합니다. 초당 프레임 증가보다 균일한 스트레인 결과를 얻을 것입니다. </li><li> 더 빨강은 이미지에 표시되지 않도록 미만 초당 1 프레임으로 셔터 속도를 조정합니다. </li><li> 5 이미지를 가져가라. </li><li> 이미지 시리즈에 포인트를 시작하고 테스트를 계산 추가합니다. </li><li> &quot;Ctrl&quot;을 누른 상태에서 배경 잡음을 관찰하기 위해 시료의 중앙을 클릭합니다. pretest 소음 microstrain 75 이상이면 교정 과정 칠을해야합니다. </li></ol> 4. 스텐 트를 배포 <ol><li> 검사 중에 걸릴 원하는 이미지의 크기를 선택합니다. 200 이미지 스텐 트 확장으로 충분합니다. </li><li> 점차적 라텍스 혈관에 카테터를 삽입하고, 그것이 중심적인 위치에 도달할 때까지 스텐 트 삽입을 안내 카테터에 마커 표시를 사용합니다. </li><li> 아라미스와 이미지를 복용 시작합니다. </li><li> 풍선 - 확장 스텐 트의 경우 점차 풍선이 완전히 확장 때까지 스텐 트를 확장 풍선 압력을 증가, 그리고 점차적으로 제로로 풍선의 압력을 감소하고 풍선 deflated와 카테터와 함께 철회합니다. </li><li> 스텐 트가 완전히 확장된 때까지 자기 확장 스텐 트의 경우 점진적으로 칼집을 제거; 후 점차적으로 카테터를 접어야합니다. </li></ol> 5. 이미지 분석 <ol><li> 선박의 특정 지점의 스트레인 역사 <ol><li> 관심 영역을 &quot;Ctrl&quot;키를 누른 채로 클릭하여 스테이지 지점을 만듭니다. </li><li> 원하는되는 변형의 유형을 선택하고, X, Y, XY, 주요 변형, 사소한 변형 또는 Mises 변형 즉 변형. </li><li> 오른쪽 하단 모서리에있는 줄거리는 테스트 기간 동안 선택된 지점에서 변형이 표시됩니다. </li></ol></li><li> 선박의 특정 경로를 따라 공간 변형 <ol><li> 크롬&quot;섹션&quot;탭을 클릭하면 multistage 포인트 라인을 eate 다음 &quot;섹션을 만듭니다.&quot; Y에서 X 축에 대한 이미지 평행의 줄을 선택 제로 같습니다. 이것은 라인의 무대 포인트의 번호를 생성합니다. </li><li> multistage 라인이 생성된 후 하단의 줄거리는 한 음모에 라인 시리즈를 표시합니다. 각 라인은 섹션의 길이를 따라 시간에 한 인스턴스의 변형을 나타냅니다. </li></ol></li><li> 혈관의 팽창 속도와 반경을 분석하기위한 최선의 적합한 실린더 만들기 <ol><li> 위쪽 도구 모음에서 다음, &quot;최고 적합한 실린더를&quot; &quot;기본형&quot;을 선택하십시오. </li><li> 오른쪽 도구 모음에서 &#39;표면을 통해 선택 &quot;도구를 사용하여 이미지의 작은 부분을 선택합니다. </li><li> 아라미스 소프트웨어는 입체 제일 적합한 실린더를 생성합니다. </li><li> 이미지는 다음 라텍스 혈관의 직경이 변화하는 방법을 관찰하는 방법을 통해 그렇게 했어요하실 수 있습니다. </li></ol></li><li> 사이의 거리를 평가두 지점 <ol><li> &quot;거리를 가리 키도록 지점&quot;에 대한 &quot;분석&quot;탭을 누릅니다. </li><li> 두 지점을 선택하여 분석을 위해 원하는되는 이미지에 길이를 선택합니다. </li><li> 이미지는 다음 시간에 따른 두 지점 사이의 거리의 변화를 관찰하기 위해 통해서 그렇게 했어요하실 수 있습니다. </li></ol></li></ol> 6. 대표 결과 스텐 트 struts는 선박 벽의 바깥쪽을 확장 변종은 일반적으로 스텐 트 위치를 중심으로 높을 것입니다. 그림 1은 하나의 특정 지점에서 풍선 - 확장형 스텐 트뿐 아니라 주요 스트레인 역사의 반동 과정에서 변형 매핑의 예입니다. 그림 1에서 검은 점들은 도관에 이러한 기준점의 변위를 캡처하고 추적하기 위해 고속 카메라가 사용되었다 기준점입니다. 기준점의 녹화 운동을 바탕으로 소프트웨어 후 도관의 변종 또는을 계산하는 데 사용됩니다NY 다른 타겟 오브젝트. 또한 최대 원금 변형율로 언급 주된 변형은 다음과 같이 계산됩니다 : <img alt="등식 1" src="/files/ftp_upload/3945/3945eq1.jpg" /> 그것은 이식 스텐 트가 혈관 표면에 비 균일한 응력 분포를 이끌 것이 분명하다. 이것은 끝을 제약 라텍스 도관과 스텐 트의 메쉬 구조의 반동 로딩에 의해 설명될 수 있습니다. 이 스트레인 필드는 그림 1의 맨 아래 이미지에서 빨간 십자 표시로 식별 스텐 트 반동의 초기 단계에 해당합니다. 특정 지점 10의 주요 스트레인 이력 곡선 스텐 트 주입의 구별 단계를 보여주었다. 풍선 확장 풍선의 수축 12 14 순간 사이에 발생에 따라 약 10~12초 및 스텐 트 반동에서 발생합니다. <img alt="그림 1" src="/files/ftp_upload/3945/3945fig1.jpg" /> 1 그림. </strong&gt; 실험 설정 (상단), stented 도관 표면 (가운데)에 비 균일한 스트레인 분포, 지점 10 (하단)의 주요 변형 역사.

<ol>
	<li>Fischman, D. L., Leon, M. B., Baim, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+randomized+comparison+of+coronary-stent+placement+and+balloon+angioplasty+in+the+treatment+of+coronary+artery+disease.+Stent+Restenosis+Study+Investigators.">A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary artery disease. Stent Restenosis Study Investigators.</a> N. Engl. J. Med. 331, 496-501 (1994).</li><li>Abul Hasan Muhammad Bashar, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+Properties+of+Various+Z-Stent+Designs:+An+Endovascular+Stent-Grafting+Perspective.">Mechanical Properties of Various Z-Stent Designs: An Endovascular Stent-Grafting Perspective.</a> Artificial Organs. 27, 714-721 (2003).</li><li>Nuutinen, J. u. h. a. -. P. e. k. k. a. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+properties+and+in+vitro+degradation+of+bioabsorbable+self-expanding+braided+stents.">Mechanical properties and in vitro degradation of bioabsorbable self-expanding braided stents.</a> Journal of Biomaterials Science -- Polymer Edition. , 255-266 (2003).</li><li>C. Schulz, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coronary+stent+symmetry+and+vascular+injury+determine+experimental+restenosis.">Coronary stent symmetry and vascular injury determine experimental restenosis.</a> Heart. 83, 462-467 (2000).</li><li>Jiménez, J. M., Davies, P. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamically+Driven+Stent+Strut+Design.">Hemodynamically Driven Stent Strut Design.</a> Annals of Biomedical Engineering. 1483, (2009).</li><li>Johnston, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Mechanical+Properties+of+Endovascular+Stents:+An+In+Vitro+Assessment.">The Mechanical Properties of Endovascular Stents: An In Vitro Assessment.</a> Cardiovascular Engineering: An International Journal. 10, 128-135 (2010).</li><li>Mejia, J. u. a. n. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+the+effect+of+stent+strut+profile+on+shear+stress+distribution+using+statistical+moments.">Evaluation of the effect of stent strut profile on shear stress distribution using statistical moments.</a> Biomedical Engineering Online. , 1-10 (2009).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> ARAMIS User Manual. , (2009).</li><li>Chesler, N. C., Thompson-Figueroa, J., Millburne, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurements+of+Mouse+Pulmonary+Biomechanics.">Measurements of Mouse Pulmonary Biomechanics.</a> Journal of Biomechanical Engineering. 126, 309-314 (2004).</li><li>de Korte, C. L., Sierevogel, M. J., Mastik, F., Strijder, C., Schaar, J. A., Velema, E., Pasterkamp, G., Serruys, P. W., van der Steen, A. F. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Atherosclerotic+Plaque+Components+With+Intravascular+Ultrasound+Elastography+In+Vivo+A+Yucatan+Pig+Study.">Identification of Atherosclerotic Plaque Components With Intravascular Ultrasound Elastography In Vivo A Yucatan Pig Study.</a> Circulation. 105, 1627-1630 (2002).</li></ol>

관심의 어떠한 충돌 선언 없습니다.

스테레오 광학 표면 스트레인 측정 시스템은 표본을 연락도없이에서와 밖에서 비행기 움직임 모두 deforming 표면에 걸쳐 현지 변종을 측정하는 데 사용됩니다. 이 시스템은 표면 변종 해결의 높은 정밀도로, 각 지점의 동작의 정확한 측정을 구축하기 위해 표면에 넣어 무작위 대조 패턴의 사진을 찍어 두 고속 광학 카메라를 사용합니다. 그것은 필요한 대조 패턴 정확한 측정?...

<table border="1"><tbody><tr><td> 장비 사용 </td><td> 회사 </td><td> 카탈로그 번호 </td><td> 댓글 </td></tr><tr><td> 아라미스 카메라 시스템 </td><td> GOM : 광학 측정 기법 </td><td></td><td></td></tr><tr><td> PALMAZ 창세기의 TRANSHEPATIC 담즙의 스텐 트 </td><td> Cordis Corporation은 </td><td> PG5910B </td><td> 풍선 확장형 스텐 트 - </td></tr><tr><td> Z-MED의 풍선 팽창의 카테터 </td><td> B. 브라운 의료 주식 회사 </td><td> PDZ336 </td><td> 풍선 팽창의 카테터 </td></tr></tbody></table>

monitoring the wall mechanics during stent deployment in a vessel

임상 실험은 다양한 스텐 트 디자인 1 가지 restenosis 속도를보고했습니다. 그것은 동맥 벽에 스텐 트 유발 스트레인 농도가 restenosis 2-7 시작하는 조직 부상으로 이어질 것이라고 예상하고 있습니다. 이 가설은 스텐 트 주입 따라 동맥의 비 균일한 스트레인 분포를보다 quantifications 포함하여 추가 조사를해야합니다. stented 동맥을위한 비 접촉 표면 스트레인 측정 방법은이 작품에 표시됩니다. 아라미스 스테레오 광학 표면 스트레인 측정 시스템은 각 기준점의 움직임을 포착해서 deforming 표면 8,9 위에 입체 변종을 해결하기 위해 두 광학 고속 카메라를 사용합니다. 메쉬 스텐 트가 바깥 표면에 분무하거나 발행한 무작위 대조되는 패턴 라텍스 그릇으로 전개되면서 표면 변형은 변형의 모든 순간에 기록됩니다. 계산 변형 배포판 그러면 이오를 이해하는 데 사용될 수칼 병변 응답은 전산 모델의 유효성을 검사하고, 생체내 연구에서 추가를위한 가설을 세웠죠.

Watch this Scientific Journal Video about Monitoring the Wall Mechanics During Stent Deployment in a Vessel at JoVE.com

Monitoring the Wall Mechanics During Stent Deployment in a Vessel

스텐 트 유도된 동맥 변형 배포판은 광학 표면 스트레인 측정 시스템을 사용하여 특징. 이러한 시각화 기술은 호스트 혈관에 스텐 트 주입의 영향에 대한 통찰력을 얻기 위해 사용됩니다.

선박의 스텐 트를 배포하는 동안 벽 역학 모니터링

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the ...

monitoring-the-wall-mechanics-during-stent-deployment-in-a-vessel

Research

JoVE Journal

Bioengineering

9.2K 조회수.  University of Nebraska-Lincoln. 스텐 트 유도된 동맥 변형 배포판은 광학 표면 스트레인 측정 시스템을 사용하여 특징. 이러한 시각화 기술은 호스트 혈관에 스텐 트 주입의 영향에 대한 통찰력을 얻기 위해 사용됩니다.

비디오: Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Magnetic Resonance Elastography Methodology for the Evaluation of Tissue Engineered Construct Growth

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use of destructive assessment is not acceptable. A proposed alternative is the use of an imaging process called magnetic resonance elastography. Elastography is a nondestructive method for determining the engineered outcome by measuring local mechanical property values (i.e., complex shear modulus), which are essential markers for identifying the structure and functionality of a tissue. As a noninvasive means for evaluation, the monitoring of engineered constructs with imaging modalities such as magnetic resonance imaging (MRI) has seen increasing interest in the past decade1. For example, the magnetic resonance (MR) techniques of diffusion and relaxometry have been able to characterize the changes in chemical and physical properties during engineered tissue development2. The method proposed in the following protocol uses microscopic magnetic resonance elastography (&mu;MRE) as a noninvasive MR based technique for measuring the mechanical properties of small soft tissues3. MRE is achieved by coupling a sonic mechanical actuator with the tissue of interest and recording the shear wave propagation with an MR scanner4. Recently, &mu;MRE has been applied in tissue engineering to acquire essential growth information that is traditionally measured using destructive mechanical macroscopic techniques5. In the following procedure, elastography is achieved through the imaging of engineered constructs with a modified Hahn spin-echo sequence coupled with a mechanical actuator. As shown in Figure 1, the modified sequence synchronizes image acquisition with the transmission of external shear waves; subsequently, the motion is sensitized through the use of oscillating bipolar pairs. Following collection of images with positive and negative motion sensitization, complex division of the data produce a shear wave image. Then, the image is assessed using an inversion algorithm to generate a shear stiffness map6. The resulting measurements at each voxel have been shown to strongly correlate (R2&gt;0.9914) with data collected using dynamic mechanical analysis7. In this study, elastography is integrated into the tissue development process for monitoring human mesenchymal stem cell (hMSC) differentiation into adipogenic and osteogenic constructs as shown in Figure 2.

The procedure demonstrates the methodology of magnetic resonance elastography for monitoring the engineered outcome of adipose and osteogenic tissue engineered constructs through noninvasive local assessment of the mechanical properties using microscopic magnetic resonance elastography (&mu;MRE).

조직 평가에 대한 자기 공명 Elastography 방법론은 구조 성장하는 기술

Traditional mechanical testing often results in the destruction of the sample, and in the case of long term tissue engineered construct studies, the use ...

연구

생체공학

Mass Cytometry: Protocol for Daily Tuning and Running Cell Samples on a CyTOF Mass Cytometer

In recent years, the rapid analysis of single cells has commonly been performed using flow cytometry and fluorescently-labeled antibodies. However, the issue of spectral overlap of fluorophore emissions has limited the number of simultaneous probes. In contrast, the new CyTOF mass cytometer by DVS Sciences couples a liquid single-cell introduction system to an ICP-MS.1 Rather than fluorophores, chelating polymers containing highly-enriched metal isotopes are coupled to antibodies or other specific probes.2-5 Because of the metal purity and mass resolution of the mass cytometer, there is no "spectral overlap" from neighboring isotopes, and therefore no need for compensation matrices. Additionally, due to the use of lanthanide metals, there is no biological background and therefore no equivalent of autofluorescence. With a mass window spanning atomic mass 103-203, theoretically up to 100 labels could be distinguished simultaneously. Currently, more than 35 channels are available using the chelating reagents available from DVS Sciences, allowing unprecedented dissection of the immunological profile of samples.6-7
Disadvantages to mass cytometry include the strict requirement for a separate metal isotope per probe (no equivalent of forward or side scatter), and the fact that it is a destructive technique (no possibility of sorting recovery). The current configuration of the mass cytometer also has a cell transmission rate of only ~25%, thus requiring a higher input number of cells.
Optimal daily performance of the mass cytometer requires several steps. The basic goal of the optimization is to maximize the measured signal intensity of the desired metal isotopes (M) while minimizing the formation of oxides (M+16) that will decrease the M signal intensity and interfere with any desired signal at M+16. The first step is to warm up the machine so a hot, stable ICP plasma has been established. Second, the settings for current and make-up gas flow rate must be optimized on a daily basis. During sample collection, the maximum cell event rate is limited by detector efficiency and processing speed to 1000 cells/sec. However, depending on the sample quality, a slower cell event rate (300-500 cells/sec) is usually desirable to allow better resolution between cells events and thus maximize intact singlets over doublets and debris. Finally, adequate cleaning of the machine at the end of the day helps minimize background signal due to free metal.

The steps necessary for daily tuning and optimization of the performance of a CyTOF mass cytometer are described. Comments on optimal sample preparation and flow rate are discussed

대량 세포 계측법 : CyTOF 질량 Cytometer에 매일 조정하고 실행 세포 샘플에 대한 프로토콜

In recent years, the rapid analysis of single cells has commonly been performed using flow cytometry and fluorescently-labeled antibodies. However, the ...

A Versatile Automated Platform for Micro-scale Cell Stimulation Experiments

Study of cells in culture (in vitro analysis) has provided important insight into complex biological systems. Conventional methods and equipment for in vitro analysis are well suited to study of large numbers of cells (&ge;105) in milliliter-scale volumes (&ge;0.1 ml). However, there are many instances in which it is necessary or desirable to scale down culture size to reduce consumption of the cells of interest and/or reagents required for their culture, stimulation, or processing. Unfortunately, conventional approaches do not support precise and reproducible manipulation of micro-scale cultures, and the microfluidics-based automated systems currently available are too complex and specialized for routine use by most laboratories. To address this problem, we have developed a simple and versatile technology platform for automated culture, stimulation, and recovery of small populations of cells (100 - 2,000 cells) in micro-scale volumes (1 - 20 &mu;l). The platform consists of a set of fibronectin-coated microcapillaries ("cell perfusion chambers"), within which micro-scale cultures are established, maintained, and stimulated; a digital microfluidics (DMF) device outfitted with "transfer" microcapillaries ("central hub"), which routes cells and reagents to and from the perfusion chambers; a high-precision syringe pump, which powers transport of materials between the perfusion chambers and the central hub; and an electronic interface that provides control over transport of materials, which is coordinated and automated via pre-determined scripts. As an example, we used the platform to facilitate study of transcriptional responses elicited in immune cells upon challenge with bacteria. Use of the platform enabled us to reduce consumption of cells and reagents, minimize experiment-to-experiment variability, and re-direct hands-on labor. Given the advantages that it confers, as well as its accessibility and versatility, our platform should find use in a wide variety of laboratories and applications, and prove especially useful in facilitating analysis of cells and stimuli that are available in only limited quantities.

We have developed an automated cell culture and interrogation platform for micro-scale cell stimulation experiments. The platform offers simple, versatile, and precise control in cultivating and stimulating small populations of cells, and recovering lysates for molecular analyses. The platform is well suited to studies that use precious cells and/or reagents.

마이크로 스케일 세포 자극 실험을위한 다목적 자동화 플랫폼

Study of cells in culture (in vitro analysis) has provided important insight into complex biological systems. Conventional methods and equipment for in ...

Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180&#176; Curved Artery Test Section

The arterial network in the human vasculature comprises of ubiquitously present blood vessels with complex geometries (branches, curvatures and tortuosity). Secondary flow structures are vortical flow patterns that occur in curved arteries due to the combined action of centrifugal forces, adverse pressure gradients and inflow characteristics. Such flow morphologies are greatly affected by pulsatility and multiple harmonics of physiological inflow conditions and vary greatly in size-strength-shape characteristics compared to non-physiological (steady and oscillatory) flows 1 - 7.
Secondary flow structures may ultimately influence the wall shear stress and exposure time of blood-borne particles toward progression of atherosclerosis, restenosis, sensitization of platelets and thrombosis 4 - 6, 8 - 13. Therefore, the ability to detect and characterize these structures under laboratory-controlled conditions is precursor to further clinical investigations.
A common surgical treatment to atherosclerosis is stent implantation, to open up stenosed arteries for unobstructed blood flow. But the concomitant flow perturbations due to stent installations result in multi-scale secondary flow morphologies 4 - 6. Progressively higher order complexities such as asymmetry and loss in coherence can be induced by ensuing stent failures vis-&#224;-vis those under unperturbed flows 5. These stent failures have been classified as &#34;Types I-to-IV&#34; based on failure considerations and clinical severity 14.
This study presents a protocol for the experimental investigation of the complex secondary flow structures due to complete transverse stent fracture and linear displacement of fractured parts (&#34;Type IV&#34;) in a curved artery model. The experimental method involves the implementation of particle image velocimetry (2C-2D PIV) techniques with an archetypal carotid artery inflow waveform, a refractive index matched blood-analog working fluid for phase-averaged measurements 15 - 18. Quantitative identification of secondary flow structures was achieved using concepts of flow physics, critical point theory and a novel wavelet transform algorithm applied to experimental PIV data 5, 6, 19 - 26.

Experimental Investigation of Secondary Flow Structures Downstream of a Model Type IV Stent Failure in a 180&amp;#176; Curved Artery Test Section

Stent implants in stenosed arterial curvatures are prone to "Type IV" failures involving the complete transverse fracture of stents and linear displacement of the fractured parts. We present a protocol for detection of secondary flow (vortical) structures in a curved artery model, downstream of clinically relevant "Type IV" stent failures.

180 ° 곡선 동맥 테스트 섹션에서 모델 유형 IV 스텐트 실패의 다운 스트림 보조 흐름 구조의 실험 조사

The arterial network in the human vasculature comprises of ubiquitously present blood vessels with complex geometries (branches, curvatures and ...

Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall

Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to intrinsic parameters within the process allow a high degree of control over scaffold characteristics including fiber diameter, alignment and porosity. By developing scaffolds with similar dimensions and topographies to organ- or tissue-specific extracellular matrices (ECM), micro-environments representative to those that cells are exposed to in situ can be created. 
The airway bronchiole wall, comprised of three main micro-environments, was selected as a model tissue. Using decellularized airway ECM as a guide, we electrospun the non-degradable polymer, polyethylene terephthalate (PET), by three different protocols to produce three individual electrospun scaffolds optimized for epithelial, fibroblast or smooth muscle cell-culture. Using a commercially available bioreactor system, we stably co-cultured the three cell-types to provide an in vitro model of the airway wall over an extended time period.
This model highlights the potential for such methods being employed in in vitro diagnostic studies investigating important inter-cellular cross-talk mechanisms or assessing novel pharmaceutical targets, by providing a relevant platform to allow the culture of fully differentiated adult cells within 3D, tissue-specific environments.

Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall

Advancements in biomaterial technologies enable the development of three-dimensional multi-cell-type constructs. We have developed electrospinning protocols to produce three individual scaffolds to culture the main structural cells of the airway to provide a 3D in vitro model of the airway bronchiole wall.

전기 방사를 적응하는 것은 트라이 계층에 대한 세 가지 독특한 환경을 제공하기 위해<em&gt; 체외</em&gt;기도 벽의 모델

Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to ...

Ferromagnetic Bare Metal Stent for Endothelial Cell Capture and Retention

Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. The feasibility of using magnetic forces to capture and retain endothelial outgrowth cells (EOC) labeled with super paramagnetic iron oxide nanoparticles (SPION) has been shown previously. But this technique requires the development of a mechanically functional stent from a magnetic and biocompatible material followed by in-vitro and in-vivo testing to prove rapid endothelialization. We developed a weakly ferromagnetic stent from 2205 duplex stainless steel using computer aided design (CAD) and its design was further refined using finite element analysis (FEA). The final design of the stent exhibited a principal strain below the fracture limit of the material during mechanical crimping and expansion. One hundred stents were manufactured and a subset of them was used for mechanical testing, retained magnetic field measurements, in-vitro cell capture studies, and in-vivo implantation studies. Ten stents were tested for deployment to verify if they sustained crimping and expansion cycle without failure. Another 10 stents were magnetized using a strong neodymium magnet and their retained magnetic field was measured. The stents showed that the retained magnetism was sufficient to capture SPION-labeled EOC in our in-vitro studies. SPION-labeled EOC capture and retention was verified in large animal models by implanting 1 magnetized stent and 1 non-magnetized control stent in each of 4 pigs. The stented arteries were explanted after 7 days and analyzed histologically. The weakly magnetic stents developed in this study were capable of attracting and retaining SPION-labeled endothelial cells which can promote rapid healing.

Our goals were to design, manufacture and test ferromagnetic stents for endothelial cell capture. Ten stents were tested for fracture and 10 more stents were tested for retained magnetism. Finally, 10 stents were tested in-vitro and 8 more stents were implanted in 4 pigs to show cell capture and retention.

내피 세포 캡처 및 유지에 대한 강자성 베어 메탈 스텐트

Rapid endothelialization of cardiovascular stents is needed to reduce stent thrombosis and to avoid anti-platelet therapy which can reduce bleeding risk. ...

Mammalian Cell Encapsulation in Alginate Beads Using a Simple Stirred Vessel

Cell encapsulation in alginate beads has been used for immobilized cell culture in vitro as well as for immunoisolation in vivo. Pancreatic islet encapsulation has been studied extensively as a means to increase islet survival in allogeneic or xenogeneic transplants. Alginate encapsulation is commonly achieved by nozzle extrusion and external gelation. Using this method, cell-containing alginate droplets formed at the tip of nozzles fall into a solution containing divalent cations that cause ionotropic alginate gelation as they diffuse into the droplets. The requirement for droplet formation at the nozzle tip limits the volumetric throughput and alginate concentration that can be achieved. This video describes a scalable emulsification method to encapsulate mammalian cells in 0.5% to 10% alginate with 70% to 90% cell survival. By this alternative method, alginate droplets containing cells and calcium carbonate are emulsified in mineral oil, followed by a decrease in pH leading to internal calcium release and ionotropic alginate gelation. The current method allows the production of alginate beads within 20 min of emulsification. The equipment required for the encapsulation step consists in simple stirred vessels available to most laboratories.

This video and manuscript describe an emulsion-based method to encapsulate mammalian cells in 0.5% to 10% alginate beads which can be produced in large batches using a simple stirred vessel. The encapsulated cells can be cultured in vitro or transplanted for cellular therapy applications.

간단한 교반 용기를 사용하여 알긴산 염 비즈에서 포유류 세포 캡슐화

Cell encapsulation in alginate beads has been used for immobilized cell culture in vitro as well as for immunoisolation in vivo. Pancreatic islet ...

Simulating the Mechanics of Lens Accommodation via a Manual Lens Stretcher

The goal of this protocol is to mimic the biomechanics of physiological accommodation in a cost-efficient, practical manner. Accommodation is achieved through the contraction of the ciliary body and relaxation of zonule fibers, which results in the thickening of the lens necessary for near vision. Here, we present a novel, simple method in which accommodation is replicated by tensing the zonules connected to the lens capsule via a manual lens stretcher (MLS). This method monitors the radial stretching achieved by a lens when subjected to a consistent force and allows for a comparison of accommodating lenses, which can be stretched, to non-accommodating lenses, which cannot be stretched. Importantly, the stretcher couples to the zonules directly, and not to the sclera of the eye, thus only requiring the lens, zonules, and ciliary body rather than the entire globe sample. This difference can significantly decrease the cost of acquiring donor cadaver lenses by about 62% compared to acquiring an entire globe.

We present an efficient method of studying lens accommodation by using a manual lens stretcher. The protocol mimics physiological accommodation by pulling the zonules connected around the lens capsule, thereby, stretching the lens.

수동 렌즈 들을 통해 렌즈 숙박의 역학을 시뮬레이션

The goal of this protocol is to mimic the biomechanics of physiological accommodation in a cost-efficient, practical manner. Accommodation is achieved ...

Nondestructive Monitoring of Degradable Scaffold-Based Tissue-Engineered Blood Vessel Development Using Optical Coherence Tomography

Engineered vascular grafts with structural and mechanical properties similar to natural blood vessels are expected to meet the growing demand for arterial bypass. Characterization of the growth dynamics and remodeling process of degradable polymer scaffold-based tissue-engineered blood vessels (TEBVs) with pulsatile stimulation is crucial for vascular tissue engineering. Optical imaging techniques stand out as powerful tools for monitoring vascularization of engineered tissue enabling high-resolution imaging in real-time culture. This paper demonstrates a nondestructive and fast real-time imaging strategy to monitor the growth and remodeling of TEBVs in long-term culture by using optical coherence tomography (OCT). Geometric morphology is evaluated, including vascular remodeling process, wall thickness, and comparison of TEBV thickness in different culture time points and presence of pulsatile stimulation. Finally, OCT provides practical possibilities for real-time observation of the degradation of polymer in the reconstructing tissues under pulsatile stimulation or not and in each vessel segment, by compared with the assessment of polymer degradation using scanning electron microscopic(SEM) and polarized microscope.

A step by step protocol for nondestructive and long-period monitoring the process of vascular remodeling and scaffold degradation in real-time culture of biodegradable polymeric scaffold-based tissue-engineered blood vessels with pulsatile stimulation using optical coherence tomography is described here.

광학 일관성 단층 촬영을 사용 하 여 분해 비 계 기반 조직 설계 혈관 개발의 비파괴 모니터링

Engineered vascular grafts with structural and mechanical properties similar to natural blood vessels are expected to meet the growing demand for arterial ...

Patterning the Geometry of Human Embryonic Stem Cell Colonies on Compliant Substrates to Control Tissue-Level Mechanics

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that correspond to primary germ layer formation during embryogenesis. Thus, these cells represent a powerful tool with which to examine the mechanisms that drive early human development. We have developed a method to culture human embryonic stem cells in confined colonies on compliant substrates that provides control over both the geometry of the colonies and their mechanical environment in order to recapitulate the physical parameters that underlie embryogenesis. The key feature of this method is the ability to generate polyacrylamide hydrogels with defined patterns of extracellular matrix ligand at the surface to promote cell attachment. This is achieved by fabricating stencils with the desired geometric patterns, using these stencils to create patterns of extracellular matrix ligand on glass coverslips, and transferring these patterns to polyacrylamide hydrogels during polymerization. This method is also compatible with traction force microscopy, allowing the user to measure and map the distribution of cell-generated forces within the confined colonies. In combination with standard biochemical assays, these measurements can be used to examine the role mechanical cues play in fate specification and morphogenesis during early human development.

Extracellular matrix ligands can be patterned onto polyacrylamide hydrogels to enable the culture of human embryonic stem cells in confined colonies on compliant substrates. This method can be combined with traction force microscopy and biochemical assays to examine the interplay between tissue geometry, cell-generated forces, and fate specification.

조직 수준 역학을 제어하기 위해 준수 기판에 인간 배아 줄기 세포 식민지의 기하학적 패터닝

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that ...