이 연구를위한 자금 조달이 (FHK에) 척수 연구 (NJCSCR)에 뉴저지위원회에 의해 제공되었다 (BLF에) CSCR14IRG005을 부여 NIH는 (CHC에) R15NS087501 및 (ETA까지) FM 커비 재단을 부여합니다.

참고 : 사용하기 전에 모든 관련 물질 안전 보건 자료 (MSDS)를 참조하십시오. 이 프로토콜에서 사용되는 화학 물질 중 일부는 독성 및 발암 성이다. 독성 또는 산 / 염기 재료를 사용하는 경우 모든 적절한 안전 사례 (흄 후드, 글러브 박스) 및 개인 보호 장비 (안전 안경, 장갑, 실험실 코트, 전체 길이 바지, 폐쇄 발가락 신발)를 사용하십시오. 소프트 리소그래피 사용하여 포토 리소그래피를위한 마스터 금형 1. 제작 <ol><li> 컴퓨터 지원 설계 (CAD)의 그리기 도구를 사용하여 마이크로 채널의 레이아웃을 그린다. </li><li> 레이저 마스크 작가를 사용하여 빈 마스크 판에 레이아웃을 인쇄합니다. </li><li> 어떠한 용매는 웨이퍼 상에 남지 않도록 질소 공기 총 이소프로판올 건조한 다음, 아세톤으로 4 인치 실리콘 웨이퍼를 헹군다. </li><li> 5 분 동안 200 ℃에서 핫 플레이트로 소성하여 웨이퍼 탈수. </li><li> 마이크로 채널의 원하는 높이에 대한 설계 네가티브 포토 레지스트를 선택합니다. 에프또는 예를 들어, 50 ㎛의 높이와 미세 채널을 얻었다 네가티브 포토 레지스트 SU-8 (50)를 사용한다. </li><li> 웨이퍼를 실온까지 냉각되도록 한 후, 스핀 코터의 척 상에 웨이퍼를 정렬. </li><li> 웨이퍼의 중심에 네가티브 포토 레지스트 4 ㎖ (웨이퍼 1 ㎖ / 인치 직경)를 분배. </li><li> 스피너를 사용하여 두 단계의 스핀 사이클에 코팅을 웨이퍼 스핀. 첫째, 10 초 100 RPM / S의 가속도와 500 rpm의 확산 사이클을 적용합니다. 그 다음 웨이퍼 상에 포토 레지스트의 50 μm의 코팅을 얻기 위해 30 초 동안 300 rpm으로 / S 2의 가속도와 2,000 rpm의 회전주기를 적용합니다. </li><li> 소프트 베이크와 제조자의 지시에 따라, 핫 플레이트에 두 단계에서 웨이퍼. 포토 레지스트의 50㎛의 코팅 먼저 프리 베이크 6 분 동안 65 ° C에서의 웨이퍼 후 바로 20 분 동안 95 ° C에서 웨이퍼 베이킹 게시 열판 온도 램프 업. </li><li> 웨이퍼를 실온까지 냉각 한 후로드 허용리소그래피 무대에 대 웨이퍼. </li><li> 마스크 얼 라이너를 사용하여 웨이퍼상의 마스크를 맞추고 220 mJ을 총 UV 조사량을 적용 (146)의 1.5 mW의 / ㎠의 강도에서 (제조자의 지시에 따라) UV 광에 웨이퍼를 노출 / cm 2 필요 포토 레지스트의 50 μm의 두께 층. </li><li> 핫 플레이트에 두 단계에서 웨이퍼에 포스트 노출 베이킹을 적용합니다. 포토 레지스트의 50 ㎛의 코팅 먼저 프리 베이크 즉시 1 분, 65 ℃에서 웨이퍼를 5 분 동안 95 ° C에서이를 베이킹 게시 열판 온도 램프 업. </li><li> SU-8 현상액에 웨이퍼를 침지하고, 기능, 웨이퍼에 명백해질 때까지 가볍게 흔들어 웨이퍼의 개발. 50 μm의 두께 포토 레지스트 ~ 6 분의 웨이퍼를 개발한다. </li><li> 이소프로판올 및 에탄올 과잉 현상을 씻어 다음, 질소 공기 총을 가진 웨이퍼를 건조. </li><li> 하드 15 분간 150 ℃에서 핫 플레이트 상에 실리콘 웨이퍼를 굽는다. </li><li> 놓고silanizing 제 25 μL로 데시 케이 터에서 웨이퍼 트리 데카 - 1,1,2,2- tetrahydrooctyl -1- 트리클로로한다. 참고 : silanizing 에이전트가 적절한 개인 보호 장비, 따라서 산 / 염기 흄 후드에서 사용되어야한다, 부식성 (보안경, 장갑, 실험실 코트, 전체 길이 바지, 신발 - 발가락을 휴관). </li><li> 5 분 동안 진공을 적용하고 진공을 해제하지 않고 30 분 동안 실란의 증기에 웨이퍼를 노출합니다. </li><li> 적절하게 크기의 페트리 접시에 웨이퍼를 전송합니다. </li></ol> 접착 테이프를 사용하여 소프트 리소그래피를위한 마스터 금형 2. 제작 <ol><li> 캐드 드로잉 도구를 사용하여 마이크로 채널의 레이아웃을 그리고 흰 종이에 드로잉을 인쇄 할 수 있습니다. </li><li> 이소프로판올 설계를 수용 한 후 공기 총 슬라이드를 건조시키는 것이 충분히 큰 유리 슬라이드를 청소한다. </li><li> 세정 된 유리 슬라이드에 접착 테이프를 부착합니다. 공기 방울 트랩에주의하지 말라. </li><li> GLA의 측면을 테이프SS는 테이프 쪽이 위로, 설계와 용지에 밀어 넣습니다. </li><li> 참고로 용지 설계를 사용하여 유리 슬라이드에 테이프를 절단하고 유리 슬라이드의 원치 않는 영역에서 테이프를 벗겨 메스를 사용한다. </li><li> 공기 총을 가진 유리 이소프로판올과 슬라이드 한 다음 건조를 씻어. 30 분 동안 65 ° C의 오븐에서 유리 슬라이드 굽는다. </li><li> 부드럽게 기포를 제거하고, 슬라이드를 실온으로 냉각 할 수 있도록 고무 롤러 테이프 롤오버. </li></ol> PDMS의 장치 3. 소프트 리소그래피 제작 <ol><li> 10의 비율로 PDMS 엘라스토머와 경화제를 혼합 1은 (W : w) 격렬하게 혼합 교반하고, 기포가 혼합물에 나타나지 않을 때까지 다음의 진공 챔버 내에 배치하여 상기 혼합물을 탈기. </li><li> 거품이 사라 모든 공기까지 1 ~ 2 mm 두께의 PDMS 층과 탈기를 얻기 위해 배양 접시에 실란 화 된 실리콘 몰드 또는 접착 테이프 금형 위에 혼합물을 붓는다. </li><li> 오븐에서 경화 PDMS2 시간 동안 65 ° C에서. </li><li> 적어도 5mm 떨어진 기능에서 PDMS 층을 잘라 메스를 사용하고 집게를 사용하여 금형 해제 경화 PDMS 벗겨. </li><li> 도 2a 및도 4b에 도시 된 바와 같이 1㎜의 생검 단일 입구 구멍은 바람직하게는 마이크로 채널 네트워크의 끝에서, 마이크로 아무 곳 펀치 펀치. </li><li> 장치에 흡착 된 먼지 입자를 제거하기 위해 접착 테이프로 캐스팅 PDMS를 청소합니다. 멸균 탈 이온수 (DI) 물에 이어 70 % 에탄올의 용액으로 세척하여 PDMS 마이크로 채널 장치 (PDMS 캐스트)을 소독하고, 30 분 동안 UV에 노출. </li><li> 사용할 때까지 멸균 페트리 접시에 멸균 PDMS 장치를 유지합니다. </li></ol> 4. 기판 패터닝 <ol><li> 멸균 유리 커버 슬립이나 배양 접시에 핀셋을 사용하여 캐스팅 멸균 PDMS를 놓고 핀셋의 끝을 사용하여 부드러운 압력을 적용합니다. 참고 : PDMS 캐스트는 GL와 컨 포멀하지만 가역 실을 수 있습니다엉덩이 커버 슬립이나 접착제를 사용하지 않고 마이크로 채널을 형성 배양 접시. </li><li> 완전히 주입구를 덮는 입구에 기질 용액 - (40 μL 20) 방울을 놓는다. 마이크로 채널의 입구에 소듐 테트라 보레이트 완충액 PDL의 20 μL 방울을 배치하여 패턴 폴리 D 라이신 (PDL). </li><li> 10 분 동안 (생물학 실험실에서 진공 집에 상당), 거품의 형태로 채널에서 나오는 공기를 준수 ~ 254 mmHgA의 진공에서 배양 접시를 넣어. </li><li> 진공을 해제하고 마이크로 채널로 유입되는 기질 용액을 관찰합니다. </li><li> 기판 준수에 대한 적절한 조건에서 접시를 품어. 표 1 및 배양 조건 2 (이 기판에 따라 다릅니다)를 참조하십시오. PDL 패터닝를 들어, 37 ° C에서 1 시간 동안 배양한다. </li><li> 조심스럽게 멸균 핀셋을 사용하여 PDMS 스탬프를 벗겨 DI 물에 세 번 유리 커버 슬립에 패턴을 씻는다. </li&gt; <li> 접시 또는 유리 커버 슬립을 커버하고 밤새 37 ° C에서 배양을 페트리 접시에 1 % 소 혈청 알부민 (BSA) 용액을 첨가. 참고 :이 코팅되지 않은 지역이 아닌 특정 부착을 줄일 수 있습니다. </li><li> 1 % BSA 용액, 및 상기 패터닝 된 기판 대기음은 이제 사용할 준비가되어있다. </li></ol> 세포의 5. 간접 패터닝 <ol><li> 무 혈청 배지에서 세포 현탁액을 준비한다. 셀 타입 및 셀 밀도를 표 1에 나열되어있다. </li><li> 패터닝 된 배양 접시에 세포 현탁액을 첨가하고 완전히 세포 현탁액의 패턴 영역 잠수함. </li><li> 세포 패터닝 기판에 부착 할 수 있도록 15 분 동안 인큐베이터 내에서 37 ° C에서 배양 접시를 부화. </li><li> 페트리 접시에서 초과 세포 현탁액을 대기음 부드럽게 부착되지 않은 세포를 제거하기 위해 10 초 동안 흔들어 섞으면 인산염 완충 생리 식염수 (PBS)으로 패턴 화 된 세포를 세 번 씻는다. </li><li> ㄱ 추가ppropriate 배양 패터닝 된 세포 배양 배지로하여 CO2 인큐베이터에서 37 ° C에서 상기 패터닝 된 세포를 배양한다. </li></ol> 세포의 6. 직접 패터닝 주 :이 기술은 세포 기질 또는 코팅없이 조직 배양 표면에 패터닝이 기술에서, 단계 5와 달리 단계 5에 기재된 간접 셀 패터닝의 대안이다. <ol><li> DI 물,이어서 70 % 에탄올의 용액으로 세척하여 미세 유체 소자를 소독. </li><li> PDMS로 세포 부착을 방지하기 위해, 1 % BSA 용액에 하룻밤 침지 장치. </li><li> 실온에서 장치를 건조하고 조직 문화 처리 된 배양 접시의 바닥에 부착. </li><li> 무 혈청 배지에서 세포 현탁액을 준비한다. 셀 타입 및 셀 밀도를 표 2에 나와있다. </li><li> 을 채우도록 세포 현탁액 - (8 μL 4) 액 적을 배치마이크로 채널은 입구에 완전히 주입구를 덮는. </li><li> 10 분 동안 진공 상태에서 페트리 접시에 넣고 기포의 형태로 채널에서 나오는 공기를 관찰한다. 진공을 해제하고 마이크로 채널로 유입되는 세포 현탁액을 관찰합니다. </li><li> 배양 조건에 따라 세포 접착 성을 촉진하는 인큐베이터에서 배양 접시를 부화하기 표 2에 언급 된 (셀 패턴의 유형에 의존). PDMS의 장치를 잠수 페트리 접시에 PBS를 추가합니다. </li><li> 껍질 PDMS 조심스럽게 핀셋으로 배양 접시 끄고 PBS와 패턴을 씻는다. 페트리 접시에 세포 배양 배지를 추가하고 배양기에서 세포 배양을 배치합니다. </li></ol>

<ol><li>Kane, R. S., Takayama, S., Ostuni, E., Ingber, D. E., Whitesides, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Patterning+proteins+and+cells+using+soft+lithography%5BTitle%5D)+AND+%22Biomaterials%22%5BJournal%5D)">Patterning proteins and cells using soft lithography.</a> Biomaterials. 20 (23-24), 2363-2376 (1999).</li>
<li>Lin, R. Z., Ho, C. T., Liu, C. H., Chang, H. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dielectrophoresis+based-cell+patterning+for+tissue+engineering%5BTitle%5D)+AND+%22Biotechnol+J%22%5BJournal%5D)">Dielectrophoresis based-cell patterning for tissue engineering.</a> Biotechnol J. 1 (9), 949-957 (2006).</li>
<li>Veiseh, M., Zareie, M. H., Zhang, M. <a target="_blank" href="http://pubs.acs.org/doi/abs/10.1021/la025529j">Highly Selective Protein Patterning on Gold-Silicon Substrates for Biosensor Applications.</a> Langmuir. 18 (17), 6671-6678 (2002).</li>
<li>Kung, F., Wang, J., Perez-Castillejos, R., Townes-Anderson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Position+along+the+nasal%2Ftemporal+plane+affects+synaptic+development+by+adult+photoreceptors%2C+revealed+by+micropatterning%5BTitle%5D)+AND+%22Integr+Biol%22%5BJournal%5D)">Position along the nasal/temporal plane affects synaptic development by adult photoreceptors, revealed by micropatterning.</a> Integr Biol. 7 (3), 313-323 (2015).</li>
<li>Dickinson, L. E., Lutgebaucks, C., Lewis, D. M., Gerecht, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Patterning+microscale+extracellular+matrices+to+study+endothelial+and+cancer+cell+interactions+in+vitro%5BTitle%5D)+AND+%22Lab+Chip%22%5BJournal%5D)">Patterning microscale extracellular matrices to study endothelial and cancer cell interactions in vitro.</a> Lab Chip. 12 (21), 4244-4248 (2012).</li>
<li>Khademhosseini, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Co-culture+of+human+embryonic+stem+cells+with+murine+embryonic+fibroblasts+on+microwell-patterned+substrates%5BTitle%5D)+AND+%22Biomaterials%22%5BJournal%5D)">Co-culture of human embryonic stem cells with murine embryonic fibroblasts on microwell-patterned substrates.</a> Biomaterials. 27 (36), 5968-5977 (2006).</li>
<li>Bogdanowicz, D. R., Lu, H. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Studying+cell-cell+communication+in+co-culture%5BTitle%5D)+AND+%22Biotechnol+J%22%5BJournal%5D)">Studying cell-cell communication in co-culture.</a> Biotechnol J. 8 (4), 395-396 (2013).</li>
<li>Choi, Y., Lee, S. <a target="_blank" href="https://link-springer-com.remotexs.ntu.edu.sg/article/10.1007/BF02916509">Guided cell growth through surface treatments.</a> J of Mech Sci Technol. 19 (11), 2133-2137 (2005).</li>
<li>Hwang, I. -T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Efficient+Immobilization+and+Patterning+of+Biomolecules+on+Poly%28ethylene+terephthalate%29+Films+Functionalized+by+Ion+Irradiation+for+Biosensor+Applications%5BTitle%5D)+AND+%22ACS+Appl+Mater+Interf%22%5BJournal%5D)">Efficient Immobilization and Patterning of Biomolecules on Poly(ethylene terephthalate) Films Functionalized by Ion Irradiation for Biosensor Applications.</a> ACS Appl Mater Interf. 3 (7), 2235-2239 (2011).</li>
<li>Clark, P., Britland, S., Connolly, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Growth+cone+guidance+and+neuron+morphology+on+micropatterned+laminin+surfaces%5BTitle%5D)+AND+%22J+Cell+Sci%22%5BJournal%5D)">Growth cone guidance and neuron morphology on micropatterned laminin surfaces.</a> J Cell Sci. 105 (1), 203-212 (1993).</li>
<li>Théry, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Micropatterning+as+a+tool+to+decipher+cell+morphogenesis+and+functions%5BTitle%5D)+AND+%22J+Cell+Sci%22%5BJournal%5D)">Micropatterning as a tool to decipher cell morphogenesis and functions.</a> J Cell Sci. 123 (24), 4201-4213 (2010).</li>
<li>Douvas, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Biocompatible+photolithographic+process+for+the+patterning+of+biomolecules%5BTitle%5D)+AND+%22Biosens+Bioelectron%22%5BJournal%5D)">Biocompatible photolithographic process for the patterning of biomolecules.</a> Biosens Bioelectron. 17 (4), 269-278 (2002).</li>
<li>Alom, R. S., Chen, C. S. <a target="_blank" href="http://pubs.rsc.org/en/Content/ArticleLanding/2007/SM/B613349E">Microcontact printing: A tool to pattern.</a> Soft Matter. 3 (2), 168-177 (2007).</li>
<li>Essö, C. <a target="_blank" href="http://www.diva-portal.org/smash/get/diva2:121034/fulltext01">Modifying Polydimethylsiloxane (PDMS) surfaces.</a> Institutionen för biologi och kemiteknik. , (2007).</li>
<li>Zhou, J., Ellis, A. V., Voelcker, N. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Recent+developments+in+PDMS+surface+modification+for+microfluidic+devices%5BTitle%5D)+AND+%22Electrophoresis%22%5BJournal%5D)">Recent developments in PDMS surface modification for microfluidic devices.</a> Electrophoresis. 31 (1), 2-16 (2010).</li>
<li>Folch, A., Jo, B. H., Hurtado, O., Beebe, D. J., Toner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microfabricated+elastomeric+stencils+for+micropatterning+cell+cultures%5BTitle%5D)+AND+%22J+Biomed+Mater+Res%22%5BJournal%5D)">Microfabricated elastomeric stencils for micropatterning cell cultures.</a> J Biomed Mater Res. 52 (2), 346-353 (2000).</li>
<li>Yeo, W. S., Yousaf, M. N., Mrksich, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dynamic+interfaces+between+cells+and+surfaces%3A+electroactive+substrates+that+sequentially+release+and+attach+cells%5BTitle%5D)+AND+%22J+Am+Chem+Soc%22%5BJournal%5D)">Dynamic interfaces between cells and surfaces: electroactive substrates that sequentially release and attach cells.</a> J Am Chem Soc. 125 (49), 14994-14995 (2003).</li>
<li>Bhatia, S. N., Toner, M., Tompkins, R. G., Yarmush, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Selective+adhesion+of+hepatocytes+on+patterned+surfaces%5BTitle%5D)+AND+%22Ann+N+Y+Acad+Sci%22%5BJournal%5D)">Selective adhesion of hepatocytes on patterned surfaces.</a> Ann N Y Acad Sci. 745, 187-209 (1994).</li>
<li>Song, E., Kim, S. Y., Chun, T., Byun, H. -J., Lee, Y. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Collagen+scaffolds+derived+from+a+marine+source+and+their+biocompatibility%5BTitle%5D)+AND+%22Biomaterials%22%5BJournal%5D)">Collagen scaffolds derived from a marine source and their biocompatibility.</a> Biomaterials. 27 (15), 2951-2961 (2006).</li>
<li>Yamato, M., Konno, C., Utsumi, M., Kikuchi, A., Okano, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Thermally+responsive+polymer-grafted+surfaces+facilitate+patterned+cell+seeding+and+co-culture%5BTitle%5D)+AND+%22Biomaterials%22%5BJournal%5D)">Thermally responsive polymer-grafted surfaces facilitate patterned cell seeding and co-culture.</a> Biomaterials. 23 (2), 561-567 (2002).</li>
<li>Takayama, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Patterning+cells+and+their+environments+using+multiple+laminar+fluid+flows+in+capillary+networks%5BTitle%5D)+AND+%22Proc+Natl+Acad+Sci+U+S+A%22%5BJournal%5D)">Patterning cells and their environments using multiple laminar fluid flows in capillary networks.</a> Proc Natl Acad Sci U S A. 96 (10), 5545-5548 (1999).</li>
<li>Kim, D. S., Lee, K. -C., Kwon, T. H., Lee, S. S. <a target="_blank" href="http://iopscience.iop.org/article/10.1088/0960-1317/12/3/307/meta">Micro-channel filling flow considering surface tension effect.</a> J of Micromech Microeng. 12 (3), 236(2002).</li>
<li>Kim, E., Xia, Y., Whitesides, G. M. <a target="_blank" href="http://pubs.acs.org/doi/abs/10.1021/ja960151v">Micromolding in Capillaries: Applications in Materials Science.</a> J Am Chem Soc. 118 (24), 5722-5731 (1996).</li>
<li>Kim, E., Xia, Y. N., Whitesides, G. M. <a target="_blank" href="http://www.nature.com/nature/journal/v376/n6541/abs/376581a0.html">Polymer Microstructures Formed by Molding in Capillaries.</a> Nature. 376 (6541), 581-584 (1995).</li>
<li>Jeon, N. L., Choi, I. S., Xu, B., Whitesides, G. M. <a target="_blank" href="https://gmwgroup.harvard.edu/pubs/pdf/665.pdf">Large-area patterning by vacuum-assisted micromolding.</a> Adv Mater. 11 (11), 946(1999).</li>
<li>Shrirao, A. B., et al. System and method for novel microfluidic device. US patent. , 61/414,237 (2010).</li>
<li>Merkel, T. C., Bondar, V. I., Nagai, K., Freeman, B. D., Pinnau, I. <a target="_blank" href="https://www.researchgate.net/publication/202178954_Gas_Sorption_Diffusion_and_Permeation_in_PolyDimethylsiloxane">Gas sorption, diffusion, and permeation in poly(dimethylsiloxane).</a> J Polym Sci Part B Polym Phys. 38 (3), 415-434 (2000).</li>
<li>Shrirao, A. B., Hussain, A., Cho, C. H., Perez-Castillejos, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Adhesive-tape+soft+lithography+for+patterning+mammalian+cells%3A+application+to+wound-healing+assays%5BTitle%5D)+AND+%22Biotechniques%22%5BJournal%5D)">Adhesive-tape soft lithography for patterning mammalian cells: application to wound-healing assays.</a> Biotechniques. 53 (5), 315-318 (2012).</li>
<li>Shrirao, A. B., Perez-Castillejos, R. <a target="_blank" href="http://blogs.rsc.org/chipsandtips/2010/05/17/simple-fabrication-of-microfluidic-devices-by-replicating-scotch-tape-masters/">Chips & tips: simple fabrication of microfluidic devices by replicating scotch-tape masters.</a> Lab Chip. , (2010).</li>
<li>Anil, B. S., Frank, H. K., Derek, Y., Cheul, H. C., Ellen, T. -A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Vacuum-assisted+fluid+flow+in+microchannels+to+pattern+substrates+and+cells%5BTitle%5D)+AND+%22Biofabrication%22%5BJournal%5D)">Vacuum-assisted fluid flow in microchannels to pattern substrates and cells.</a> Biofabrication. 6 (3), 035016(2014).</li>
<li>Yuen, P. K., Goral, V. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Low-cost+rapid+prototyping+of+flexible+microfluidic+devices+using+a+desktop+digital+craft+cutter%5BTitle%5D)+AND+%22Lab+on+a+Chip%22%5BJournal%5D)">Low-cost rapid prototyping of flexible microfluidic devices using a desktop digital craft cutter.</a> Lab on a Chip. 10 (3), 384-387 (2010).</li>
<li>Wang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-loading+and+cell+culture+in+one+layer+microfluidic+devices%5BTitle%5D)+AND+%22Biomed+Microdevices%22%5BJournal%5D)">Self-loading and cell culture in one layer microfluidic devices.</a> Biomed Microdevices. 11 (3), 679-684 (2009).</li>
<li>Feng, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Survival+of+mammalian+cells+under+high+vacuum+condition+for+ion+bombardment%5BTitle%5D)+AND+%22Cryobiology%22%5BJournal%5D)">Survival of mammalian cells under high vacuum condition for ion bombardment.</a> Cryobiology. 49 (3), 241-249 (2004).</li>
<li>Haubert, K., Drier, T., Beebe, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((PDMS+bonding+by+means+of+a+portable%2C+low-cost+corona+system%5BTitle%5D)+AND+%22Lab+on+a+Chip%22%5BJournal%5D)">PDMS bonding by means of a portable, low-cost corona system.</a> Lab on a Chip. 6 (12), 1548-1549 (2006).</li>
<li>Fan, D. -H., Yuan, S. -W., Shen, Y. -M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Surface+modification+with+BSA+blocking+based+on+in+situ+synthesized+gold+nanoparticles+in+poly+%28dimethylsiloxane%29+microchip%5BTitle%5D)+AND+%22Colloids+Surf%2C+B%22%5BJournal%5D)">Surface modification with BSA blocking based on in situ synthesized gold nanoparticles in poly (dimethylsiloxane) microchip.</a> Colloids Surf, B. 75 (2), 608-611 (2010).</li>
<li>Hideshima, S., Sato, R., Inoue, S., Kuroiwa, S., Osaka, T. <a target="_blank" href="https://www-sciencedirect-com.remotexs.ntu.edu.sg/science/article/pii/S0925400511008902">Detection of tumor marker in blood serum using antibody-modified field effect transistor with optimized BSA blocking.</a> Sens Actuator B-Chem. 161 (1), 146-150 (2012).</li>
<li>Zheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((High-throughput+immunoassay+through+in-channel+microfluidic+patterning%5BTitle%5D)+AND+%22Lab+on+a+Chip%22%5BJournal%5D)">High-throughput immunoassay through in-channel microfluidic patterning.</a> Lab on a Chip. 12 (14), 2487-2490 (2012).</li>
<li>MacLeish, P., Barnstable, C., Townes-Anderson, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Use+of+a+monoclonal+antibody+as+a+substrate+for+mature+neurons+in+vitro%5BTitle%5D)+AND+%22Procs+Nat+Acad+of+Sci%22%5BJournal%5D)">Use of a monoclonal antibody as a substrate for mature neurons in vitro.</a> Procs Nat Acad of Sci. 80 (22), 7014-7018 (1983).</li>
<li>Suchodolskis, A., et al. <a target="_blank" href="http://onlinelibrary.wiley.com/doi/10.1002/sia.3763/abstract">Elastic properties of chemically modified baker's yeast cells studied by AFM.</a> Surf Interface Anal. 43 (13), 1636-1640 (2011).</li>
</ol>

The authors declare no competing financial interests.

기존의 포토 리소그래피 소프트 리소그래피, 장비, 재료 및 기존의 포토 리소그래피를 사용하는 데 필요한 기술을위한 금형 제작을위한 잘 확립 된 기술이지만 대부분의 실험실에 쉽게 사용할 수 없습니다. 이 자원에 대한 접근없이 실험실을 위해, 우리는 마이크로 유체 장치를위한 비교적 단순한 기능 주형을 만드는 방법으로 접착 테이프 제조를 제시 하였다. 이 방법은 어떤 기관이 작성하고 ?...

조직 공학 및 바이오 센서에서는 μm의 규모 단백질 및 세포의 공간 조직을 제어하는 능력은, 마지막 네 수십 1, 2, 3 위로 갈수록 중요 해지고있다. 단백질 및 세포의 정확한 공간적 조직 연구자들은 세포 증식을 유도하고, 바이오 센서 4, 5, 6, 7, 8의 제조에 생체 분자를 고정하기 위해, 세포의 유사하거나 또는 상이한 유형을 포함하는 셀과 기판 사이의 상호 작용을 조사 할 수있다 9. 패터닝 단백질의 현재의 방법은 포토 패터닝 및 마이크로 콘택트 인쇄를 포함한다. 포토 패터닝은 ultr에 노출시 가교 감광 재료를 사용바이올렛 (UV) 빛. (UV 광 투과를 방지하는 어두운 영역과 투명 영역으로 구성된) 포토 마스크에 관한 UV 빛은 생체 물질 또는 셀 (10), (11)의 후속 연결을 위해 사용할 수있는 특정 지역에 가교 결합시킨다. 이 방식은 매우 정확하고 배양 표면의 지형을 정밀하게 제어 할 수 있지만, 이는 UV 방사 (12)에 의해 패터닝 될 수 UV 성 생체 제한된다. 마이크로 콘택트 인쇄는 특정 단백질 13, 14 패턴의 또 다른 인기있는 방법입니다. 이 방법에서, 폴리 디메틸 실록산 (PDMS) 스탬프 선택된 생체 분자 기판의 용액에 침지되기 전에 표면 개질 다양한 시약으로 처리한다. 그 다음 부드럽게 따라서 배양 표면에 생체 분자를 &quot;스탬프&quot;유리 커버 슬립 또는 다른 표면 상에 가압된다. 호Wever에게는 스탬핑은 PDMS 15 스탬프 표면에 생체 분자의 습윤성뿐만 아니라 전송 될 수있는 물질의 종류로 제한된다. 세포를 직접 패터닝은 더 어려울 수 및 특정 세포 부착 분자 (16) (17)와 스위칭 기판 공판 기반 방법 또는 패터닝과 같은 복잡한 방법에 의존 할 수있다. 이러한 방법으로 인해 호환 세포 접착 기재의 부족 패턴 셀 능력에 제한이 프로세스의 호환성이 중요한 생물학적 세포 및 제약 패터닝 재생의 불일치 및 절차의 복잡도와 함께 작동한다. 예를 들면, 전환 가능한 기질 맞춤 기판 &lt;공정 17에서 사용 된 UV 광 및 열 노출시 열화없이 특정 세포 유형에 대한 그들의 부착 전환 모든 세포 유형을 위해 설계 될 필요<html> SUP 클래스 = &quot;외부 참조&quot;&gt; 18, 19, 20. 스텐실 기반의 패터닝 방법은 패턴 셀 능력에 다목적; 그러나, 게다가 16, 21에 해당하는 두께로 PDMS 스텐실을 제조하는 것이 곤란하다. 1) 미세 유체 채널의 제조에 용이하고 다양한 세포와 ​​기질 2) 적합성 : PDMS 미세 유체 채널로 세포를 직접 주입은 몇 가지 장점 등이있다. 그러나, 기포를 감소시키는 플라즈마 세정 또는 다른 방법을 사용하지 않고 PDMS의 소수성에 주입 공정 중에 기포 포착의 보급 문제는 어려운 일관 유리 또는 플라스틱 표면 (21)상의 패턴 화 된 세포를 생성 할 수있다. 이 작품은, 모세관 마이크로 몰딩 (22), (23)에 확장아가씨 = &quot;외부 참조&quot;&gt; 24, 25, 26는 마이크로 채널에 단백질 및 세포 현탁액을 주입하는 방법을보고한다. 여기에 사용 된 방법은 기판의 패터닝 및 특정 세포 유형의 직간접 패터닝을 나타낸다. 이 기술은 PDMS의 높은 소수성을 극복 PDMS (27)의 가스 투과성을 이용하여 하나의 기판 또는 세포 주입시 기포의 존재를 제거한다. 이 논문은 여러 가지 기판과 세포 유형과 기술을 사용하는 방법을 보여줍니다. 이 문서에서는 또한 기존의 포토 리소그래피뿐만 아니라 자원에서 유용 간단하고 저렴한 비용으로 접착 테이프 방법 제한 설정 28, 29를 사용하여 소프트 리소그래피를위한 금형의 제작을 강조한다.

<table><tbody><tr><td>CorelDRAW X4 CAD Drawing Tools</td><td>Corel Corporation, Canada</td><td>X4 Version 14.0.0.701</td><td>CAD tool used to draw the layout of the microfluidic device</td></tr><tr><td>Laser Printer HP</td><td>Hewlett Packard, CA</td><td>1739629</td><td>Used to print the layout of microfluidic device for adhesive tape technique</td></tr><tr><td>Bel-Art Dessicator</td><td>Fisher Scientific, MA</td><td>08-594-16B</td><td>Used to degass the PDMS mixture</td></tr><tr><td>Adhesive Scotch Tape</td><td>3M Product, MN</td><td>Tape 600</td><td>Used to fabricate adhesive tape Master</td></tr><tr><td>PDMS Sylgard 184</td><td>Dow Corning, MI</td><td>1064291</td><td>Casting polymer</td></tr><tr><td>Petri Dish</td><td>Fisher Scientific, MA</td><td>08-772-23</td><td>Used to keep the mold to cast with PDMS</td></tr><tr><td>Stainless steel Scalpel (#3) with blade (# 11)</td><td>Feather Safety Razor Co. Ltd. Japan</td><td>2976#11</td><td>Used to cut the PDMS</td></tr><tr><td>Tweezers</td><td>Ted Pella, CA</td><td>5627-07</td><td>Used to handle the PDMS cast during peeling</td></tr><tr><td>Glass slides</td><td>Fisher Scientific, MA</td><td>12-546-2</td><td>Used as surface to pattern the Substrate</td></tr><tr><td>Glass slides</td><td>Fisher Scientific, MA</td><td>12-544-4</td><td>Used as surface to pattern the Substrate</td></tr><tr><td>Rubber Roller</td><td>Dick Blick Art Materials, IL</td><td>40104-1004</td><td>Used to attach adhesive tape on glass without trapping air bubbles</td></tr><tr><td>Laser Mask Writer</td><td>Heidelberg Instruments, Germany</td><td>DWL66fs</td><td>Used to fabricate quartz mask used in photolithography fabrication process</td></tr><tr><td>EVG Mask Aligner (Photolithography UV exposure tool)</td><td>EV Group, Germany</td><td>EVG 620T(B)</td><td>Used to expose the photoresist to UV light</td></tr><tr><td>Spin Coater Headway</td><td>Headway Research Inc, TX</td><td>PWM32-PS-CB15PL</td><td>Used to spin coat the photoresist on silicon wafer</td></tr><tr><td>Photoresists SU-8 50</td><td>MicroChem, MA</td><td>Y131269</td><td>Negative photoresist used for mold fabrication</td></tr><tr><td>SU-8 Devloper</td><td>MicroChem, MA</td><td>Y020100</td><td>Photoresist developer</td></tr><tr><td>Tridecafluoro-1,1,2,2-Tetrahydrooctyl-1-Trichlorosilane</td><td>UCT Specialties, PA</td><td>T2492-KG</td><td>Coat mold to avoid PDMS adhesion</td></tr><tr><td>Isopropanol</td><td>Sigma-Aldrich, MO</td><td>190764</td><td>Cleaning Solvent</td></tr><tr><td>Ethanol</td><td>Sigma-Aldrich, MO</td><td>24102</td><td>Sterilization Solvent</td></tr><tr><td>Poly-D-Lysine hydrobromide (PDL)</td><td>Sigma-Aldrich, MO</td><td>P0899-10MG</td><td>PDL solution is made at 0.1 mg/mL in Sodium Tetraborate Buffer</td></tr><tr><td>Laminin</td><td>Sigma-Aldrich, MO</td><td>L2020</td><td>Laminin aliquoted into 10 &amp;micro;L aliquots and diluted to 20 &amp;micro;g/&amp;micro;L in PBS prior to use</td></tr><tr><td>BSA</td><td>Fisher Scientific, MA</td><td>BP1605100</td><td>Cell culture</td></tr><tr><td>C2C12 Myoblast cell lline</td><td>ATCC, VA</td><td>CRL-1722</td><td>Used to demonstrate C2C12 patterning</td></tr><tr><td>PC12 Cell Line</td><td>ATCC, VA</td><td>CRL-1721</td><td>Used to demonstrate PC12 patterning</td></tr><tr><td>Collagen type 1, rat tail</td><td>BD Biosciences</td><td>40236</td><td>Cell culture</td></tr><tr><td>DMEM</td><td>GIBCO, MA</td><td>11965-084</td><td>Cell culture</td></tr><tr><td>Horse Serum, heat inactivated</td><td>Fisher Scientific, MA</td><td>26050-070</td><td>Cell culture</td></tr><tr><td>Phalloidin-tetramethylrhodamine B isothiocyanate (TRITC)</td><td>Sigma-Aldrich, MO</td><td>P1951</td><td>To label cells</td></tr><tr><td>Calcein-AM live dead cell Assay kit</td><td>Invitrogen, MA</td><td>L-3224</td><td>Cell viability Assay</td></tr><tr><td>Biopsy Hole Punch</td><td>Ted Pella, CA</td><td>15110-10</td><td>Punched hole in PDMS</td></tr></tbody></table>

a versatile method of patterning proteins and cells

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning techniques work well only with simple shapes, small areas and selected bio-materials. This article describes a method to distribute cell suspensions as well as substrate solutions into complex, long, closed (dead-end) polydimethylsiloxane (PDMS) microchannels using negative pressure. This method enables researchers to pattern multiple substrates including fibronectin, collagen, antibodies (Sal-1), poly-D-lysine (PDL), and laminin. Patterning of substrates allows one to indirectly pattern a variety of cells. We have tested C2C12 myoblasts, the PC12 neuronal cell line, embryonic rat cortical neurons, and amphibian retinal neurons. In addition, we demonstrate that this technique can directly pattern fibroblasts in microfluidic channels via brief application of a low vacuum on cell suspensions. The low vacuum does not significantly decrease cell viability as shown by cell viability assays. Modifications are discussed for application of the method to different cell and substrate types. This technique allows researchers to pattern cells and proteins in specific patterns without the need for exotic materials or equipment and can be done in any laboratory with a vacuum.

이 방법은 단백질 및 마스터 주형이 이루어지면 거의 모든 생물 실험실에서 10 μm의 가능한 장비 한 작은 치수 데드 엔드 미세 유체 채널을 사용하여 세포의 간접 패터닝의 패터닝을 허용한다. 이 기술은 기존의 소프트 리소그래피, 또는 접착 테이프의 제작 (도 1) (28) (29)로 작성된 PDMS 미세 유체 채널을 사용하여 생?...

Watch this Scientific Journal Video about A Versatile Method of Patterning Proteins and Cells at JoVE.com

A Versatile Method of Patterning Proteins and Cells

This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research.

패터닝 단백질과 세포의 다목적 방법

Substrate and cell patterning techniques are widely used in cell biology to study cell-to-cell and cell-to-substrate interactions. Conventional patterning ...

a-versatile-method-of-patterning-proteins-and-cells

Research

JoVE Journal

Bioengineering

9.3K 조회수.  Rutgers University. This report describes a simple, easy to perform technique, using low pressure vacuum, to fill microfluidic channels with cells and substrates for biological research.

비디오: A Versatile Method of Patterning Proteins and Cells

Creating Two-Dimensional Patterned Substrates for Protein and Cell Confinement

Microcontact printing provides a rapid, highly reproducible method for the creation of well-defined patterned substrates.1 While microcontact printing can be employed to directly print a large number of molecules, including proteins,2 DNA,3 and silanes,4 the formation of self-assembled monolayers (SAMs) from long chain alkane thiols on gold provides a simple way to confine proteins and cells to specific patterns containing adhesive and resistant regions. This confinement can be used to control cell morphology and is useful for examining a variety of questions in protein and cell biology. Here, we describe a general method for the creation of well-defined protein patterns for cellular studies.5 This process involves three steps: the production of a patterned master using photolithography, the creation of a PDMS stamp, and microcontact printing of a gold-coated substrate. Once patterned, these cell culture substrates are capable of confining proteins and/or cells (primary cells or cell lines) to the pattern.
The use of self-assembled monolayer chemistry allows for precise control over the patterned protein/cell adhesive regions and non-adhesive regions; this cannot be achieved using direct protein stamping. Hexadecanethiol, the long chain alkane thiol used in the microcontact printing step, produces a hydrophobic surface that readily adsorbs protein from solution. The glycol-terminated thiol, used for backfilling the non-printed regions of the substrate, creates a monolayer that is resistant to protein adsorption and therefore cell growth.6 These thiol monomers produce highly structured monolayers that precisely define regions of the substrate that can support protein adsorption and cell growth. As a result, these substrates are useful for a wide variety of applications from the study of intercellular behavior7 to the creation of microelectronics.8
While other types of monolayer chemistry have been used for cell culture studies, including work from our group using trichlorosilanes to create patterns directly on glass substrates,9 patterned monolayers formed from alkane thiols on gold are straight-forward to prepare. Moreover, the monomers used for monolayer preparation are commercially available, stable, and do not require storage or handling under inert atmosphere. Patterned substrates prepared from alkane thiols can also be recycled and reused several times, maintaining cell confinement.10

Self-assembled monolayers (SAMs) formed from long chain alkane thiols on gold provide well-defined substrates for the formation of protein patterns and cell confinement. Microcontact printing of hexadecanethiol using a polydimethylsiloxane (PDMS) stamp followed by backfilling with a glycol-terminated alkane thiol monomer produces a pattern where protein and cells adsorb only to the stamped hexadecanethiol region.

단백질과 세포 교도소에 대한 2 차원 문양의 기판 만들기

Microcontact printing provides a rapid, highly reproducible method for the creation of well-defined patterned substrates.1  While microcontact printing ...

연구

생체공학

Cell Co-culture Patterning Using Aqueous Two-phase Systems

Cell patterning technologies that are fast, easy to use and affordable will be required for the future development of high throughput cell assays, platforms for studying cell-cell interactions and tissue engineered systems. This detailed protocol describes a method for generating co-cultures of cells using biocompatible solutions of dextran (DEX) and polyethylene glycol (PEG) that phase-separate when combined above threshold concentrations. Cells can be patterned in a variety of configurations using this method. Cell exclusion patterning can be performed by printing droplets of DEX on a substrate and covering them with a solution of PEG containing cells. The interfacial tension formed between the two polymer solutions causes cells to fall around the outside of the DEX droplet and form a circular clearing that can be used for migration assays. Cell islands can be patterned by dispensing a cell-rich DEX phase into a PEG solution or by covering the DEX droplet with a solution of PEG. Co-cultures can be formed directly by combining cell exclusion with DEX island patterning. These methods are compatible with a variety of liquid handling approaches, including manual micropipetting, and can be used with virtually any adherent cell type.

Aqueous two-phase systems were used to simultaneously pattern multiple populations of cells. This fast and easy method for cell patterning takes advantage of the phase separation of aqueous solutions of dextran and polyethylene glycol and the interfacial tension that exists between the two polymer solutions.

수성 2 단계 시스템을 사용하여 셀 공동 문화 패턴

Cell patterning  technologies that are fast, easy to use and affordable will be required for the  future development of high throughput cell assays, ...

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

포토 리소그래피 정의 파릴 렌-C에 대한 세포 패터닝 : 그런가<sub&gt; 2</sub&gt; 기판

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

Microcontact Printing of Proteins for Cell Biology

The ability to pattern proteins and other biomolecules onto substrates is important for capturing the spatial complexity of the extracellular environment. Development of microcontact printing by the Whitesides group (<a href="http://gmwgroup.harvard.edu/">http://gmwgroup.harvard.edu/</a>) in the mid-1990s revolutionalized this field by making microelectronics/microfabrication techniques accessible to laboratories focused on the life sciences. Initial implementations of this method used polydimethylsiloxane (PDMS) stamps to create patterns of functionalized chemicals on material surfaces1. Since then, a range of innovative approaches have been developed to pattern other molecules, including proteins2. This video demonstrates the basic process of creating PDMS stamps and uses them to pattern proteins, as these steps are difficult to accurately express in words. We focus on patterning the extracellular matrix protein fibronectin onto glass coverslips as a specific example of patterning.
An important component of the microcontact printing process is a topological master, from which the stamps are cast; the raised and lowered regions of the master are mirrored into the stamp and define the final pattern. Typically, a master consists of a silicon wafer coated with photoresist and then patterned by photolithography, as is done here. Creation of masters containing a specific pattern requires specialized equipment, and is best approached in consultation with a fabrication center or facility. However, almost any substrate with topology can be used as a master, such as plastic diffraction gratings (see Reagents for one example), and such serendipitous masters provide readily available, simple patterns. This protocol begins at the point of having a master in hand.

Microcontact printing is used extensively to pattern proteins and other molecules on material surfaces. We demonstrate the basic steps of this process, stamping patterns of fibronectin onto glass.

세포 생물학을위한 단백질의 Microcontact 인쇄

The ability to pattern proteins and other biomolecules onto substrates is important for capturing the spatial complexity of the extracellular environment. ...

생물학

Mapping the Emergent Spatial Organization of Mammalian Cells using Micropatterns and Quantitative Imaging

A fundamental goal in biology is to understand how patterns emerge during development. Several groups have shown that patterning can be achieved in vitro when stem cells are spatially confined onto micropatterns, thus setting up experimental models which offer unique opportunities to identify, in vitro, the fundamental principles of biological organisation.
Here we describe our own implementation of the methodology. We adapted a photo-patterning technique to reduce the need for specialized equipment to make it easier to establish the method in a standard cell biology laboratory. We also developed a free, open-source and easy to install image analysis framework in order to precisely measure the preferential positioning of sub-populations of cells within colonies of standard shapes and sizes. This method makes it possible to reveal the existence of patterning events even in seemingly disorganized populations of cells. The technique provides quantitative insights and can be used to decouple influences of the environment (e.g., physical cues or endogenous signaling), on a given patterning process.

The method presented here uses micropatterning together with quantitative imaging to reveal spatial organization within mammalian cultures. The technique is easy to establish in a standard cell biology laboratory and offers a tractable system to study patterning in vitro.

마이크로패턴과 정량적 이미징을 사용하여 포유류 세포의 응급 공간 조직 매핑

A fundamental goal in biology is to understand how patterns emerge during development. Several groups have shown that patterning can be achieved in vitro ...

발생학

Micropatterning Transmission Electron Microscopy Grids to Direct Cell Positioning within Whole-Cell Cryo-Electron Tomography Workflows

Whole-cell cryo-electron tomography (cryo-ET) is a powerful technology that is used to produce nanometer-level resolution structures of macromolecules present in the cellular context and preserved in a near-native frozen-hydrated state. However, there are challenges associated with culturing and/or adhering cells onto TEM grids in a manner that is suitable for tomography while retaining the cells in their physiological state. Here, a detailed step-by-step protocol is presented on the use of micropatterning to direct and promote eukaryotic cell growth on TEM grids. During micropatterning, cell growth is directed by depositing extra-cellular matrix (ECM) proteins within specified patterns and positions on the foil of the TEM grid while the other areas remain coated with an anti-fouling layer. Flexibility in the choice of surface coating and pattern design makes micropatterning broadly applicable for a wide range of cell types. Micropatterning is useful for studies of structures within individual cells as well as more complex experimental systems such as host-pathogen interactions or differentiated multi-cellular communities. Micropatterning may also be integrated into many downstream whole-cell cryo-ET workflows, including correlative light and electron microscopy (cryo-CLEM) and focused-ion beam milling (cryo-FIB).

The goal of this protocol is to direct cell adhesion and growth to targeted areas of grids for cryo-electron microscopy. This is achieved by applying an anti-fouling layer that is ablated in user-specified patterns followed by deposition of extra-cellular matrix proteins in the patterned areas prior to cell seeding.

전세포 극저온-전자 단층 촬영 워크플로우 내의 직접 세포 위치지정에 마이크로패턴 전송 전자 현미경 검사기 그리드

Whole-cell cryo-electron tomography (cryo-ET) is a powerful technology that is used to produce nanometer-level resolution structures of macromolecules ...

생화학

Preparation of Tunable Extracellular Matrix Microenvironments to Evaluate Schwann Cell Phenotype Specification

Traumatic peripheral nervous system (PNS) injuries currently lack suitable treatments to regain full functional recovery. Schwann cells (SCs), as the major glial cells of the PNS, play a vital role in promoting PNS regeneration by dedifferentiating into a regenerative cell phenotype following injury. However, the dedifferentiated state of SCs is challenging to maintain through the time-period needed for regeneration and is impacted by changes in the surrounding extracellular matrix (ECM). Therefore, determining the complex interplay between SCs and differing ECM to provide cues of regenerative potential of SCs is essential. To address this, a strategy was created where different ECM proteins were adsorbed onto a tunable polydimethylsiloxane (PDMS) substrate which provided a platform where stiffness and protein composition can be modulated. SCs were seeded onto the tunable substrates and critical cellular functions representing the dynamics of SC phenotype were measured. To illustrate the interplay between SC protein expression and cellular morphology, differing seeding densities of SCs in addition to individual microcontact printed cellular patterns were utilized and characterized by immunofluorescence staining and western blot. Results showed that cells with a smaller spreading area and higher extent of cellular elongation promoted higher levels of SC regenerative phenotypic markers. This methodology not only begins to unravel the significant relationship between the ECM and cellular function of SCs, but also provides guidelines for the future optimization of biomaterials in peripheral nerve repair.

This methodology aims to illustrate the mechanisms by which extracellular matrix cues such as substrate stiffness, protein composition and cell morphology regulate Schwann cell (SC) phenotype.

슈완 세포 표현형 사양을 평가하기 위한 튜블드 세포 외 세포 매트릭스 미세 환경의 준비

Traumatic peripheral nervous system (PNS) injuries currently lack suitable treatments to regain full functional recovery. Schwann cells (SCs), as the ...

Simple, Affordable, and Modular Patterning of Cells using DNA

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells of the same or different type, micropatterning techniques have proved useful. DNA Programmed Assembly of Cells (DPAC) is a micropatterning technique that targets the adhesion of cells to a substrate or other cells using DNA hybridization. The most basic operations in DPAC begin with decorating cell membranes with lipid-modified oligonucleotides, then flowing them over a substrate that has been patterned with complementary DNA sequences. Cells adhere selectively to the substrate only where they find a complementary DNA sequence. Non-adherent cells are washed away, revealing a pattern of adherent cells. Additional operations include further rounds of cell-substrate or cell-cell adhesion, as well as transferring the patterns formed by DPAC to an embedding hydrogel for long-term culture. Previously, methods for patterning oligonucleotides on surfaces and decorating cells with DNA sequences required specialized equipment and custom DNA synthesis, respectively. We report an updated version of the protocol, utilizing an inexpensive benchtop photolithography setup and commercially available cholesterol modified oligonucleotides (CMOs) deployed using a modular format. CMO-labeled cells adhere with high efficiency to DNA-patterned substrates. This approach can be used to pattern multiple cell types at once with high precision and to create arrays of microtissues embedded within an extracellular matrix. Advantages of this method include its high resolution, ability to embed cells into a three-dimensional microenvironment without disrupting the micropattern, and flexibility in patterning any cell type.

Here we present a protocol to micropattern cells at single-cell resolution using DNA-programmed adhesion. This protocol uses a benchtop photolithography platform to create patterns of DNA oligonucleotides on a glass slide and then labels cell membranes with commercially available complementary oligonucleotides. Hybridization of the oligos results in programmed cell adhesion.

DNA를 사용하여 세포의 간단하고, 적당한, 모듈식 패터닝

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells ...

Control of Cell Geometry through Infrared Laser Assisted Micropatterning

Micropatterning is an established technique in the cell biology community used to study connections between the morphology and function of cellular compartments while circumventing complications arising from natural cell-to-cell variations. To standardize cell shape, cells are either confined in 3D molds or controlled for adhesive geometry through adhesive islands. However, traditional micropatterning techniques based on photolithography and deep UV etching heavily depend on clean rooms or specialized equipment. Here we present an infrared laser assisted micropatterning technique (microphotopatterning) modified from Doyle et al. that can be conveniently set up with commercially available imaging systems. In this protocol, we use a Nikon A1R MP+ imaging system to generate micropatterns with micron precision through an infrared (IR) laser that ablates preset regions on poly-vinyl alcohol coated coverslips. We employ a custom script to enable automated pattern fabrication with high efficiency and accuracy in systems not equipped with a hardware autofocus. We show that this IR laser assisted micropatterning (microphotopatterning) protocol results in defined patterns to which cells attach exclusively and take on the desired shape. Furthermore, data from a large number of cells can be averaged due to the standardization of cell shape. Patterns generated with this protocol, combined with high resolution imaging and quantitative analysis, can be used for relatively high throughput screens to identify molecular players mediating the link between form and function.

The protocol presented here enables automated fabrication of micropatterns that standardizes cell shape to study cytoskeletal structures within mammalian cells. This user-friendly technique can be set up with commercially available imaging systems and does not require specialized equipment inaccessible to standard cell biology laboratories.

적외선 레이저 보조 마이크로패터닝을 통한 세포 지오메트리 제어

Micropatterning is an established technique in the cell biology community used to study connections between the morphology and function of cellular ...

Pattern Generation for Micropattern Traction Microscopy

Micropattern traction microscopy allows control of the shape of single cells and cell clusters. Furthermore, the ability to pattern at the micrometer length scale allows the use of these patterned contact zones for the measurement of traction forces, as each micropatterned dot allows for the formation of a single focal adhesion that then deforms the soft, underlying hydrogel. This approach has been used for a wide range of cell types, including endothelial cells, smooth muscle cells, fibroblasts, platelets, and epithelial cells. 
This review describes the evolution of techniques that allow the printing of extracellular matrix proteins onto polyacrylamide hydrogels in a regular array of dots of prespecified size and spacing. As micrometer-scale patterns are difficult to directly print onto soft substrates, patterns are first generated on rigid glass coverslips that are then used to transfer the pattern to the hydrogel during gelation. First, the original microcontact printing approach to generate arrays of small dots on the coverslip is described. A second step that removes most of the pattern to leave islands of small dots is required to control the shapes of cells and cell clusters on such arrays of patterned dots. 
Next, an evolution of this approach that allows for the generation of islands of dots using a single subtractive patterning step is described. This approach is greatly simplified for the user but has the disadvantage of a decreased lifetime for the master mold needed to make the patterns. Finally, the computational approaches that have been developed for the analysis of images of displaced dots and subsequent cell-generated traction fields are described, and updated versions of these analysis packages are provided.

We describe improvements to a standard method for measuring cellular traction forces, based on microcontact printing with a single subtractive patterning step of dot arrays of extracellular matrix proteins on soft hydrogels. This method allows for simpler and more consistent fabrication of island patterns, essential for controlling cell cluster shape.

마이크로패턴 견인 현미경을 위한 패턴 생성

Micropattern traction microscopy allows control of the shape of single cells and cell clusters. Furthermore, the ability to pattern at the micrometer ...