이 연구는 건강 허가 번호 R01NS050452 및 R01EB009429의 국립 연구소에 의해 투자되었다. 캔틸레버 칩의 제조는 코넬 대학교 (Cornell University)에있는 나노 제조 시설에서 공동 작업자에 의해 외부에서 수행 하였다. 캔틸레버의 제조 공정에서 사용되는 모든 설비는이 설비에 위치했다. 캔틸레버 마이크로 제조 그들의 도움 맨디 에슈와 Jean-마티유 보호 해주는 특별 감사. 캔틸레버 기능의 비디오 애니메이션 UCF의 합성 현실 연구실에서 찰스 휴즈, 알렉스 Zelenin 에릭 임페리얼에 의해 생성되었습니다.

1 캔틸레버 칩 제작 설명 제조 단계의 일러스트에 대한 자세한 내용은 그림 1에 나와 있습니다. <ol><li> 오븐에서 실리콘 - 온 - 절연체 (SOI) 웨이퍼를 배치하고이를 탈수 20 분 동안 125 ° C에서 굽는다. </li><li> 플라즈마를 이용하여 탈수 한 SOI 웨이퍼의 무늬 층 상에 산화 규소 1.5 μm의 두께 층을 증착은 화학 기상 증착 (PECVD)을 첨단 공구. </li><li> 장치 층이 위를 향하도록 스핀 코터 척에 웨이퍼를 놓습니다. , 웨이퍼 중심 확인 1000 RPM / sec로 가속에 60 초간 3000 rpm에서 웨이퍼의 중심과 스핀에 P20 프라이머 2 ㎖를 분배. P20 프라이머 장치 층에 포토 레지스트의 접착을 촉진시킨다. </li><li> 웨이퍼 스핀 코터의 척에있는 동안, O 1,000 RPM / sec로 가속에서 60 초 동안 3000 rpm에서 S1818의 웨이퍼의 중심에 포토 레지스트 스핀 2 ㎖를 분배포토 레지스트의 1.5 μm의 두께 층을 btain. </li><li> 핫 플레이트에 웨이퍼를 놓고 1 분 동안 115 ° C에서 소프트 베이크를 수행합니다. </li><li> 디바이스 층 상에 포토 레지스트 마스크로부터 캔틸레버 패턴을 전사하기 위해 포토 리소그래피 콘택트 마스크 얼 라이너를 사용하여 하드 콘택트 UV 노광을 수행한다. 125 엠제이 / S1818 포토 레지스트 cm (2)의 노광 에너지 값에 기초한 노출 시간을 계산한다. </li><li> 부드럽게 앞뒤로 흔들어 섞으면 웨이퍼를 1 분간 726 MIF 포토 레지스트 현상액에 웨이퍼를 침지하여 포토 레지스트를 개발한다. </li><li> 탈 이온화 (DI) 물과 웨이퍼를 씻어 바람직 스핀 세척 건조기 (SRD) 도구를 사용하여, 그것을 건조. </li><li> 아세톤에 적신 면봉을 사용하여 (가장자리에서 5mm까지) 웨이퍼의 가장자리에서 포토 레지스트를 제거합니다. </li><li> 포토 레지스트면이 위를 향하도록, 깊은 반응성 이온 에칭 (DRIE) 도구에서 웨이퍼를로드하고, 데비을 통해 패턴 화 된 실리콘 층을 에칭 조리법을 실행CE 층. 에칭 정지로서 매립 산화막 기능하므로 완전한 에칭을 보장 할 필요가있을 것으로 예상되는 것보다 100 % 이상의 사이클 50 %로 에칭을 수행한다. </li><li> 포토 레지스트를 제거하기 위해 20 분 동안 뜨거운 레지스트 욕 용액에 웨이퍼를 배치했다. DI 워터와 웨이퍼를 씻어 빠른 덤프 - 린서 (QDR)에 웨이퍼를 전송합니다. 포토 레지스트 스트립을 따라 헹구고 웨이퍼를 건조 SRD 도구에서 웨이퍼를로드합니다. 예상대로 캔틸레버 패턴이 나타날 수 있도록 현미경으로 웨이퍼를 검사한다. </li><li> PECVD 도구를 사용하여 웨이퍼의 장치 층에 언 도핑 실리콘 산화물의 1 μm의 두께 층을 증착. 상기 처리 단계 동안 캔틸레버 보호 층 등이 산화물 층 기능한다. </li><li> 웨이퍼의 뒷면의 처리를 시작하도록 대향 핸들 층과 스핀 코터의 척에 웨이퍼를 배치했다. 확인 웨이퍼는 3,000 rpm에서 P20의 웨이퍼의 중심에 프라이머, 스핀 2 ㎖를 분배, 중앙1000 RPM / 초 가속에 60 초 동안. </li><li> 웨이퍼 스핀 코터의 척에있는 동안의 6.5 μm의 두께의 층을 얻기 위해 1,000 RPM / sec로 가속에서 45 초 동안 2000 rpm에서 웨이퍼의 중심과 스핀 상 SPR220-4.5 포토 레지스트 2 ㎖를 분배 포토 레지스트. </li><li> 2 분 동안 115 ° C에서 소프트 베이크을 수행하기 위해 근접 핫 플레이트에 웨이퍼를 놓습니다. </li><li> 앞 / 뒷면 정렬 가능한 포토 리소그래피 콘택트 노광 장치를 사용하여, 전방 측 캔틸레버 패턴이면 윈도우 마스크를 정렬 및 처리 층 상에 포토 레지스트를이면 윈도우 마스크로부터 패턴을 전사하기 위해 하드 콘택트 UV 노광을 수행한다. 480 엠제이 / SPR220-4.5 감광액 cm (2)의 노광 에너지 값에 기초하여 계산 된 노출 시간을 사용한다. </li><li> UV 노광 후, 웨이퍼는 다음 처리 단계 이전에 30 분 동안 어두운 영역에 남아하자. </li><li> 웨이퍼에 침지하여 포토 레지스트를 개발2 분 동안 726 MIF 포토 레지스트 개발 부드럽게 앞뒤로 웨이퍼를 떨고있다. </li><li> 탈 이온화 (DI) 물과 웨이퍼를 씻어 바람직 스핀 세척 건조기 (SRD) 도구를 사용하여, 그것을 건조. </li><li> 12 시간 동안 90 ° C의 오븐에서 웨이퍼를 놓습니다. </li><li> 불소 가스와 RIE 시스템 및 산화물을 에칭하기위한 레시피를 이용하여 상기 웨이퍼의이면에 산화 실리콘 층을 에칭. 웨이퍼의이면에 패터닝 된 산화물은 추가 처리를위한 에칭 마스크로서 작용한다. 노광 창에 실리콘 산화물이 완전히 에칭되도록하여 현미경으로 웨이퍼를 검사한다. </li><li> 아세톤에 담근 클린 룸 면봉을 사용하여 (가장자리에서 5mm까지) 웨이퍼의 가장자리에 포토 레지스트를 제거합니다. </li><li> DRIE와 도구의 웨이퍼를 적재 및 에칭 정지 같이 매립 산화물 층 (500)으로 기능하는 μM의 깊이로 패터닝 처리 층을 에칭 레시피를 실행. 의 과열을 방지하기 위해, 복수의 런에이 에칭 분할실리콘의 에칭에 모순이 발생 웨이퍼. 이 에칭 단계는 완전히 캔틸레버 아래의 실리콘을 제거한다. </li><li> 캔틸레버 아래의 매몰 산화물 층과 상기 캔틸레버의 위에 보호 산화물 층을 제거하기 위해, 25 % 희석 HF 에칭 제를 사용하는 습식 에칭 단계를 수행한다. 참고 :이 단계는 실리콘 캔틸레버의 바닥면을 해제하고 또한 레이저로 캔틸레버를 조사 할 수있는 액세스를 제공하기 위해 아래 창을 엽니 다. </li><li> DI 물 화장실의 시리즈와 함께 조심스럽게 건조 질소를 이용하여 웨이퍼를 헹군다. 캔틸레버가 기지만을 지원하기 때문에, 직접 칸틸 레버에 DI 물 또는 불활성 가스의 강제 스프레이를 사용하지 않는다. </li><li> 핸들 층 에칭 단계 동안 생성 쪼개짐 라인을 따라 웨이퍼로부터 개개의 칩을 쪼갠다. </li></ol> 2 세포 배양 <ol><li> 이전에 게시 된 방법 17에 따라 13F 된 커버를 준비합니다. 참고 : 만약 13F 코브rslips는 사용할 수 없으며, 95 ° 이상의 접촉각이 소수성으로 모든 표면이 사용될 수있다. </li><li> 캔틸레버 칩 및 70 % 에탄올 용액 중의 13F 커버 슬립을 소독하고 흐름 후드에서 공기 건조하도록 허용. </li><li> 표준 12 웰 플레이트 내부 13F 된 커버의 상단에 각각의 캔틸레버 칩을 놓습니다. </li><li> 외투 세포 유형에 대해 최적화 생체 고분자 또는 표면 변형에 캔틸레버는 표준 세포 배양 프로토콜에 따라 사용된다. </li><li> 원하는 농도의 특정 성장 배지에서 세포를 다시 일시. 참고 :이 프로토콜은 캔틸레버 창을 통해 떨어지는 원하는 캔틸레버 표면에 부착하지 세포의 상당수가 발생합니다. 세포 제제 따라서 커버 슬립 표준 제제에 비해 3-4 배 더 집중해야한다. 예를 들어, 쥐 골격근 위성 세포의 파종은 일반적 500-700 셀 / 평방 mm 15,16의 시딩 밀도를 이용하여 수행된다및 / 평방 mm 2000 세포에서 캔틸레버 기판에 사용됩니다. 최적화 실험은 적절한 파종 밀도를 확인하기 위해 새로운 셀 소스로 수행되어야한다. </li><li> 매체의 기포가 완전히 캔틸레버 창 커버 보장 캔틸레버 칩 표면에 세포 현탁액 200 μl를 피펫. 매체가 창을 통해 심지 및 캔틸레버의 상단에 고정 기포를 형성하지 않으면 13F의 커버 슬립을 장착하고 도금을 다시 시도. </li><li> 인큐베이터에 칩을 함유하는 접시를 전송하고 세포가 적어도 1 시간 (바람직하게는 2 ~ 3 시간)에 대해 부착 할 수있다. </li><li> 이 도금 기간이 지나면 성장 배지 1 ㎖와 문화를 13F coverslip에없이 깨끗하고 잘에 칩을 전송하고, 상단까지 멸균 집게를 사용합니다. </li><li> 인큐베이터에 접시를 돌려줍니다. </li><li> 커버 슬립에 체외 유지 보수를 위해 자신의 표준 프로토콜에 따라 세포를 유지한다. 골격근 세포,세포가 합류가 필요합니다이되면 매체 조성물의 스위치는 myotube 형성을 유도한다. </li></ol> 캔틸레버 변형 분석을위한 하드웨어 및 소프트웨어의 3 설치 <ol><li> 수직 전기 생리학 현미경의 무대로 가열 된 배양 접시를 놓습니다. </li><li> 가열 현미경 단계로 세포가 현재 (+ 10 mM의 HEPES)에 현탁 된 공급 매체의 3 ML을 추가합니다. </li><li> 15mm의 이격 거리에서 가열 된 배양 접시의 안쪽에 스테인리스 전극을 장착하고, 펄스 발생기에 가변 강도, 주파수 및 파형의 필드 자극 펄스를 생성 할 수있는 그들을 연결 시스템들 자극을 생성 할 수 있도록 적절한 때 세포의. </li><li> , 현미경 테이블의 밑면에, XY 병진 스테이지 상에 장착 헬륨 - 네온 레이저를 볼트와, 레이저 빔이 30 ° 각도로 상대 금지로 가열 된 배양 접시의 바닥을 통해 향하도록하여 조정할캔틸레버의 평면 전자. </li><li> , 현미경 스테이지의 밑면에, XY 병진 스테이지 상에 장착 사분면 광 검출기 모듈을 볼트와 4 사분면의 중앙 반사 레이저 빔 토지.도 2를하도록 위치를 조정하여 설정할 하드웨어의 개요를 제공한다 설명 된 프로토콜을 구현하는 데 필요한. </li><li> 캔틸레버에 걸쳐 스캔 선형 액추에이터를 제어하는​​ 소프트웨어 프로그램을 작성합니다. 도 3에서 제공하는 흐름도를 참조하여 소프트웨어 프로그램을 작성한다.이 시스템을 사용하기 위해 프로그램 된 그래픽 인터페이스는도 4에 제공된다. </li></ol> 4 녹음 캔틸레버 편향 데이터 <ol><li> 캔틸레버 분석 하드웨어 및 관련 소프트웨어를 켭니다. </li><li> 중간에 가열 단계 서미스터를 삽입하고 37 ° C를 읽을 때까지 기다립니다. </li><li> cantileve와 함께 무대에 캔틸레버 칩을 삽입스테이지의 오른손쪽으로 향한 RS. </li><li> 현미경 광원을 켜십시오. </li><li> 캔틸레버 가정하면 스테이지의 오른쪽, 캔틸레버 (1)에 배향되어보기로 캔틸레버의 가장자리를 가져오고 캔틸레버 1 NOTE의 팁에 레이저 빔을 위치 시키도록, 레이저 / 광 검출기 제어 소프트웨어를 사용하는 현미경 초점 배열의 왼쪽 상단에 위치 하나이며, 숫자는 왼쪽 아래에서 아래로 16까지 실행합니다. 캔틸레버 (17)는 우측 상단 위치에 있고, 오른쪽 아래 (도 5a)에서 (32)에 실행된다. </li><li> 눌러 레코딩 소프트웨어의 &quot;놀이&quot;. </li><li> 신호가 광 검출기를 제어하는​​ 스텝퍼 모터를 조정함으로써, x 및 y의 범위에 모두 &quot;0&quot;을 읽을 수 있도록 광 검출기를 배치. </li><li> 레이저 / 광 검출기 제어 소프트웨어에서 설정 캔틸레버 한 위치 (그림 4). </li><li> . 단계 4.7를 반복 캔틸레버 (16)의 끝 부분에 레이저를 이동하고 cantilev 설정ER 레이저 / 광 검출기 제어 소프트웨어 (16)에 위치. </li><li> 레이저 / 광 검출기 제어 소프트웨어의 단계 4.7. 및 설정 캔틸레버 (32)의 위치를​​ 반복 캔틸레버 (32)의 끝 부분에 레이저를 이동합니다. </li><li> 레이저 / 광 검출기 제어 소프트웨어의 단계 4.7. 및 설정 캔틸레버 (17)의 위치를​​ 반복 캔틸레버 (17)의 끝 부분에 레이저를 이동합니다. </li><li> 현미경 광원 및 실험실에서 오버 헤드 빛을 끄십시오. </li><li> 레코딩 소프트웨어 눌러 &quot;레코드&quot;. </li><li> 1 Hz의 주파수에서 40 밀리 초, 5 V 펄스에 대한 펄스 발생기 하드웨어를 설정하고 기기 전원을 켭니다. NOTE : 선택적으로,이 시점에서 특정 셀 소스에 대한 최적의 자극 프로토콜을 사용, 명시된 설정 인간 및 설치류 세포 12,13,15,16 소스를 사용하여 수집 된 데이터에 기초하여 가이드 라인이다. </li><li> 레이저 / 광 검출기 제어 소프트웨어를 사용하여, 각각에 5 초 동안 정지, 캔틸레버 어레이 (32)를 가로 질러 스캔 할 하드웨어 설정전자. </li><li> 캔틸레버 (32)의 스캔이 완료되면, 다음 기록 소프트웨어를 중단하고 데이터 파일을 불러 자극기를 끄. </li><li> 수축 활동의 증거에 대한 각각의 캔틸레버에서 기록 추적을 검사합니다. 긍정적 인 반응과 함께 각 캔틸레버를 기록해 둡니다. 편향 기준선 위에 적어도 0.1 V이면 수축 피크로서 정의된다. </li><li> 레이저 / 광 검출기 제어 소프트웨어에 스캔 프로토콜에서 모든 응답하지 캔틸레버를 제거합니다. </li><li> 활성 캔틸레버이어서 세포의 자발적인 수축 활성의 판독을 얻기 위해 자극없이 재검사 될 수있다. </li><li> 배양 된 세포의 기능의 출력에 미치는 영향을 관찰하기 위해 중간에 치료 학적 화합물을 첨가 한 다음, 함께 또는 넓은 전기장 자극없이 검사를 실행. </li><li> 장기간 전기적 및 CONTR의 주사 레벨 셀을 자극하여 피로 평가를 수행<html> actility는 특정 임계 값 아래로 떨어 피크 힘 걸리는 시간을 측정합니다. </li><li> 운동 신경이 근육과 공동 문화 유지된다 실험에서 신경 근육 신경 자극과 운동 신경 - myotube 캔틸레버의 공동 문화의 치료를 통해 접합 형성 (예 : 글루탐산) 또는 시냅스 억제제를 측정 (예를 들어, D-tubocurarine) 및 스캔 자발적인 활동의 증가와 감소는 각각 16. </li><li> 계획된 실험의 요구에 의해 결정으로 특정 검사를 수행합니다. </li></ol> 캔틸레버 편향 데이터의 분석 (5) <ol><li> 사용 스토니 방정식 15 전지 층 또는 myotube (파스칼 단위), 및 (나노 뉴튼) 셀룰러 수축력의 직접 측정에서 응력의 판독에 (볼트) 것의 캔틸레버 편향 데이터를 변환 (아래에 설명) 개질 : 광고 / 51,866 / 51866eq1.jpg &quot;/&gt; 식 1 <img alt="식 (2)" fo:content-width="2in" width="300" src="/files/ftp_upload/51866/51866eq2.jpg" /> 식 (2) </li><li> δ = 캔틸레버 팁 편향 및 응력 myotube 의해 제조하는 경우, σ C 균일 후막보기 캔틸레버, C 검출부의 전체 폭을 가정 myotube 의해 생성 = 응력 = 사진에 레이저 위치 전압 관련 시스템 특정 계수 검출기, θ = 캔틸레버의 평면에 레이저 및 검출기 상대적인 각도, E 실리콘은 실리콘의 탄성률 = t시는 캔틸레버의 두께 = t F = myotube 두께, V의 Si =의 독 송비 규소, L = 캔틸레버 길이 검출기 캔틸레버 선단으로부터 레이저의 P = 경로 길이, w <sub&gt; 실리콘 캔틸레버의 폭 =. 이들 방정식에서 사용되는 용어를 설명하기 개략은도 6에 제공된다. </li><li> 균일 한 필름이 myotube이다 가정 myotube에 힘 스토니의 적용에 사용 된 응력으로부터 힘의 계산 및 추정 셀 단면적을 동일시하여, 3을 수학 식 이어지는 막의 힘 같다 식. <img alt="식 (3)" fo:content-width="1.5in" src="files/ftp_upload/51866/51866eq3.jpg" /> 식 (3) </li><li> 기능 데이터 수집 후, 면역 세포 화학 분석을 위해 캔틸레버 칩을 수정하거나 표준 기술을 사용하여 단백질 또는 DNA 분석을위한 세포를 사용한다. </li><li> 선택적으로 나중 포인트에서 기능적 성능을 재평가하기 위해 인큐베이터 대신 분자 분석을위한 준비에 세포를 반환. </li></ol>

<ol>
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The authors have nothing to disclose.

셀룰러 수축 증거 마이크로 캔틸레버를 분석하는데 중요한 단계는 현미경 스테이지 내의 캔틸레버 칩의 배치 및 배열 코너 캔틸레버 팁과 레이저와 광 검출기의 후속 정렬이다. 이 정확하게 수행하지 않은 경우, 소프트웨어는 잠재적으로 데이터를 수집하는 동안 위음성의 축적으로 이어지는 배열 잔존 캔틸레버의 위치를​​ 추정 할 수 없습니다. 운영자는 캔틸레버 칩이 레이저의 위치를​​ ?...

The in vitro culture of muscle cells from both human and rodent sources has been possible for decades1,2. However, while standard coverslip preparations are useful for biochemical assessment, they do not facilitate analysis of the cell&#8217;s primary functional output (contractility), and therefore are of somewhat limited value as a means to assess cellular maturation and performance. In order to maximize the amount of data obtainable from such in vitro cultures, it is necessary to advance the development of systems capable of housing such cells in configurations that permit the real-time assessment of their functional performance. The establishment of a multitude of three dimensional muscle models has made some progress toward fulfilling this need, and such systems have been used in a number of publications as a means to assess the contractile capacity of cultured muscle cells in vitro3-5. While such systems are invaluable for tissue modeling and reconstruction studies, they are limited in their applicability for studies of single cell responses. In such cases where single fiber studies are necessary, complex and labor intensive ex vivo methodologies remain the only option6-10. Furthermore, current movement toward the development of complex, multi-organ platforms for drug development and screening protocols requires the establishment of systems which are non-invasive, easily scalable and which integrate readily with supporting cells and tissue models11. 
Microscale cantilevers offer a simple method for assessing the functional contractile capacity of single cells/small populations of cells12,13. The technique is based on modified Atomic Force Microscopy (AFM) technology14, and uses a laser and photo-detector system to measure microscale cantilever deflection in response to cultured myotube contractile activity. Modified Stoney&#8217;s equations are then used to calculate stress in the myotube, and the force exerted by the myotube in order to generate the observed substrate deflection15. A scanning program has been written which enables simultaneous assessment of multiplexed cantilever arrays, offering potential moderate to high through-put applications for drug toxicity/efficacy studies15,16. Such technology may prove invaluable in the development of functional, pre-clinical assays for predicting drug efficacy in vivo. Furthermore, fabrication of cantilever chips in silicon does not impede post analysis processing of cells for standard biomolecular assays such as immunostaining, western blotting and PCR. 
This manuscript provides detailed instructions on the fabrication and preparation of microscale silicon cantilevers, the hardware and software set-up, and the operating guidelines for assessing the functionality of contractile cells cultured on these chips. Standard cell culture techniques can be implemented for plating and maintenance of cells on these surfaces, hence any contractile cell type for which reliable culture parameters exist should be able to integrate with this device with ease. The relatively simple 2D culture parameters utilized in this system makes integration of other cell models or addition of cell types that can interact with muscle (such as innervating neurons) straight-forward, greatly increasing the applicability of this model in the development of more complex functional in vitro assays and multi-organ models of mammalian systems.

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			<td height="17" style="height:17px;width:299px;">Name of material/ equipment</td>
			<td style="width:128px;">Company</td>
			<td style="width:108px;">Catalog number</td>
			<td style="width:156px;">Comments/ Description</td>
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			<td height="17" style="height:17px;">Primary rat muscle growth medium</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Neurobasal medium</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">21103-049&#160;</td>
			<td dir="LTR" style="width:156px;">N/A</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">B27 (50x)</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">17504044</td>
			<td dir="LTR" style="width:156px;">1x</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Glutamax (100x)</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">35050061</td>
			<td dir="LTR" style="width:156px;">1x</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">G5 supplement</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">17503-012&#160;</td>
			<td dir="LTR" style="width:156px;">1x</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Glial-Derived Neurotrophic Factor</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRG400B</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Brain-Derived Neurotrophic Factor</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRB600B</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Ciliary Neurotrophic Factor</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRC400A</td>
			<td dir="LTR" style="width:156px;">40 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Neurotrophin-3</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRN500B</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Neurotrophin-4</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRN501B</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Acidic Fibroblast Growth Factor</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">13241-013&#160;</td>
			<td dir="LTR" style="width:156px;">25 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Vascular Endothelial Growth Factor</td>
			<td dir="LTR" style="width:128px;">Life Technologies</td>
			<td dir="LTR" style="width:108px;">P2654</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Cardiotrophin-1</td>
			<td dir="LTR" style="width:128px;">Cell sciences</td>
			<td dir="LTR" style="width:108px;">CRC700B</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Heparin Sulphate</td>
			<td dir="LTR" style="width:128px;">Sigma</td>
			<td dir="LTR" style="width:108px;">D9809&#160;</td>
			<td dir="LTR" style="width:156px;">100 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Leukemia Inhibitory Factor</td>
			<td dir="LTR" style="width:128px;">Sigma</td>
			<td dir="LTR" style="width:108px;">L5158&#160;</td>
			<td dir="LTR" style="width:156px;">20 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">Vitronectin</td>
			<td dir="LTR" style="width:128px;">Sigma</td>
			<td dir="LTR" style="width:108px;">V0132</td>
			<td dir="LTR" style="width:156px;">100 ng/ ml</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;"></td>
			<td dir="LTR" style="width:128px;"></td>
			<td dir="LTR" style="width:108px;"></td>
			<td dir="LTR" style="width:156px;"></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Primary rat muscle differentiation medium</td>
			<td dir="LTR" style="width:128px;"></td>
			<td dir="LTR" style="width:108px;"></td>
			<td dir="LTR" style="width:156px;"></td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;">NB Activ 4</td>
			<td dir="LTR" style="width:128px;">Brain Bits LLC</td>
			<td dir="LTR" style="width:108px;">NB4-500</td>
			<td dir="LTR" style="width:156px;">N/A</td>
		</tr>
		<tr height="17">
			<td dir="LTR" height="17" style="height:17px;width:299px;"></td>
			<td dir="LTR" style="width:128px;"></td>
			<td dir="LTR" style="width:108px;"></td>
			<td dir="LTR" style="width:156px;"></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Class 2 red diode laser</td>
			<td>Newport</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Photo-detector</td>
			<td>Noah Industries</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Model 2100 Pulse stimulator</td>
			<td>A-M systems</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Multiclamp 700B Digitizer</td>
			<td>Axon Instruments</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Patch clamp microscope and stage</td>
			<td>Olympus</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Delta T4 culture dish controller</td>
			<td>Bioptechs</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Axoscope software</td>
			<td>Molecular Devices</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">LabVIEW software</td>
			<td>National Instruments</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;"></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">37oC, 5% CO2 incubator</td>
			<td>NAPCO</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Class 2 microbiological flow hood</td>
			<td>Labconco</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">Pipettes and tips</td>
			<td>Eppendorf</td>
			<td>N/A</td>
			<td></td>
		</tr>
	</tbody>
</table>

utilization of microscale silicon cantilevers to assess cellular contractile function in vitro

더 많은 예측과 관련된 생물학적 시험 관내 분석법의 개발은 시드 세포의 기능 평가를 용이 다목적 세포 배양 시스템의 발전에 입각한다. 이를 위해 마이크로 캔틸레버 벤딩 기술은 기판의 수축에 의한 평가를 통해, 뼈, 심장, 및 평활근 세포를 포함한 세포 유형의 범위의 수축 기능을 측정 할 수있는 플랫폼을 제공한다. 다중화 된 캔틸레버 어레이의 적용은 약물의 효능과 독성 질환 표현형 및 진행뿐만 아니라, 신경 근육 및 기타 세포 - 세포 상호 작용을 평가하기위한 높은 처리량 프로토콜 중등도 개발 수단을 제공한다. 이 논문은이 목적을 위해 신뢰할 수있는 캔틸레버 어레이를 제조하기위한 상세하고, 이들 표면에 성공적으로 세포 배양에 필요한 방법을 제공한다. 또한 설명은 기능적 항문을 수행하는 데 필요한 단계를 제공한다수축성 세포 유형의 ysis는 신규 한 레이저 및 광 검출기 시스템을 사용하여 이러한 배열에서 유지. 하이라이트 정밀도 및이 시스템을 사용하여 가능 수축력의 분석 재현성을 제공하는 자연 대표 데이터뿐만 아니라, 연구의 넓은 범위는 이러한 기술이 적용될 수있다. 이 시스템의 성공은 널리 채택 수단 조사관 티슈 성능 질환 개발 및 신규 한 치료 적 처치에 대한 응답의 더 정확한 예측 선도, 시험관 내에서 신속, 저비용으로 기능 연구를 수행하기 위해 제공 할 수있다.

캔틸레버에 수축성 세포의 성공적인 배양은 표준 세포 배양 기술 (도 5)를 이용하여, 비교적 간단한 절차이다. 수축 세포를지지 캔틸레버 백분율 세포 유형에 따라 달라질 것은 검사 및 특정 배양 기술이 채용되고있다. 쥐의 뒷다리에서 파생 된 기본 배아 세포를 사용하여 수축 활동이 조사 캔틸레버의 12 %에서 검출되었다 (N = 4). 설명 된 레이저와 광 검출기 시스템을 사용 수축력 분?...

Watch this Scientific Journal Video about Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro at JoVE.com

Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro

이 프로토콜은 시험 관내에서 근육 세포의 수축력을 측정하기위한 유연한 배양 표면과 같은 실리콘 마이크로 캔틸레버의 사용을 설명한다. 셀룰러 수축 측정 기록하고, 시험 관내에서 수축력을 측정하는 비 침습적이고 확장 가능한 시스템을 제공하고, 힘의 판독 값으로 변환 할 수 외팔보 굽힘을 야기.

마이크로 실리콘 캔틸레버의 이용은 세포 수축 기능을 평가하기 위해<em&gt; 체외</em

The development of more predictive and biologically relevant in vitro assays is predicated on the advancement of versatile cell culture systems which ...

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Research

JoVE Journal

Bioengineering

Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro

10.1K 조회수.  University of Central Florida.  이 프로토콜은 시험 관내에서 근육 세포의 수축력을 측정하기위한 유연한 배양 표면과 같은 실리콘 마이크로 캔틸레버의 사용을 설명한다. 셀룰러 수축 측정 기록하고, 시험 관내에서 수축력을 측정하는 비 침습적이고 확장 가능한 시스템을 제공하고, 힘의 판독 값으로 변환 할 수 외팔보 굽힘을 야기. 

비디오: Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro

Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological research. Perhaps the most widely used physical force to achieve noninvasive manipulation of small particles has been dielectrophoresis(DEP).1 However, DEP on its own lacks the versatility and precision that are desired when manipulating cells since it is traditionally done with stationary electrodes. Optical tweezers, which utilize a three dimensional electromagnetic field gradient to exert forces on small particles, achieve this desired versatility and precision.2 However, a major drawback of this approach is the high radiation intensity required to achieve the necessary force to trap a particle which can damage biological samples.3 A solution that allows trapping and sorting with lower optical intensities are optoelectronic tweezers (OET) but OET's have limitations with fine manipulation of small particles; being DEP-based technology also puts constraint on the property of the solution.4,5
This video article will describe two methods that decrease the intensity of the radiation needed for optical manipulation of living cells and also describe a method for orientation control. The first method is plasmonic tweezers which use a random gold nanoparticle (AuNP) array as a substrate for the sample as shown in Figure 1. The AuNP array converts the incident photons into localized surface plasmons (LSP) which consist of resonant dipole moments that radiate and generate a patterned radiation field with a large gradient in the cell solution. Initial work on surface plasmon enhanced trapping by Righini et al and our own modeling have shown the fields generated by the plasmonic substrate reduce the initial intensity required by enhancing the gradient field that traps the particle.6,7,8 The plasmonic approach allows for fine orientation control of ellipsoidal particles and cells with low optical intensities because of more efficient optical energy conversion into mechanical energy and a dipole-dependent radiation field. These fields are shown in figure 2 and the low trapping intensities are detailed in figures 4 and 5. The main problems with plasmonic tweezers are that the LSP's generate a considerable amount of heat and the trapping is only two dimensional. This heat generates convective flows and thermophoresis which can be powerful enough to expel submicron particles from the trap.9,10 The second approach that we will describe is utilizing periodic dielectric nanostructures to scatter incident light very efficiently into diffraction modes, as shown in figure 6.11 Ideally, one would make this structure out of a dielectric material to avoid the same heating problems experienced with the plasmonic tweezers but in our approach an aluminum-coated diffraction grating is used as a one-dimensional periodic dielectric nanostructure. Although it is not a semiconductor, it did not experience significant heating and effectively trapped small particles with low trapping intensities, as shown in figure 7. Alignment of particles with the grating substrate conceptually validates the proposition that a 2-D photonic crystal could allow precise rotation of non-spherical micron sized particles.10 The efficiencies of these optical traps are increased due to the enhanced fields produced by the nanostructures described in this paper.

Plasmonic tweezers and photonic crystal nanostructures are shown to produce useful enhancements in the efficiency and orientation control of optically trapping micro- and nano-particles.

향상된 마이크로 및 Nanoparticle 조작에 대한 Plasmonic 및 광자 크리스탈 Nanostructures 활용

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological ...

연구

생체공학

In vitro Assembly of Semi-artificial Molecular Machine and its Use for Detection of DNA Damage

Naturally occurring bio-molecular machines work in every living cell and display a variety of designs 1-6. Yet the development of artificial molecular machines centers on devices capable of directional motion, i.e. molecular motors, and on their scaled-down mechanical parts (wheels, axels, pendants etc) 7-9. This imitates the macro-machines, even though the physical properties essential for these devices, such as inertia and momentum conservation, are not usable in the nanoworld environments 10. Alternative designs, which do not follow the mechanical macromachines schemes and use mechanisms developed in the evolution of biological molecules, can take advantage of the specific conditions of the nanoworld. Besides, adapting actual biological molecules for the purposes of nano-design reduces potential dangers the nanotechnology products may pose. Here we demonstrate the assembly and application of one such bio-enabled construct, a semi-artificial molecular device which combines a naturally-occurring molecular machine with artificial components. From the enzymology point of view, our construct is a designer fluorescent enzyme-substrate complex put together to perform a specific useful function. This assembly is by definition a molecular machine, as it contains one 12. Yet, its integration with the engineered part - fluorescent dual hairpin - re-directs it to a new task of labeling DNA damage12.
Our construct assembles out of a 32-mer DNA and an enzyme vaccinia topoisomerase I (VACC TOPO). The machine then uses its own material to fabricate two fluorescently labeled detector units (Figure 1). One of the units (green fluorescence) carries VACC TOPO covalently attached to its 3'end and another unit (red fluorescence) is a free hairpin with a terminal 3'OH. The units are short-lived and quickly reassemble back into the original construct, which subsequently recleaves. In the absence of DNA breaks these two units continuously separate and religate in a cyclic manner. In tissue sections with DNA damage, the topoisomerase-carrying detector unit selectively attaches to blunt-ended DNA breaks with 5'OH (DNase II-type breaks)11,12, fluorescently labeling them. The second, enzyme-free hairpin formed after oligonucleotide cleavage, will ligate to a 5'PO4 blunt-ended break (DNase I-type breaks)11,12, if T4 DNA ligase is present in the solution 13,14 . When T4 DNA ligase is added to a tissue section or a solution containing DNA with 5'PO4 blunt-ended breaks, the ligase reacts with 5'PO4 DNA ends, forming semi-stable enzyme-DNA complexes. The blunt ended hairpins will interact with these complexes releasing ligase and covalently linking hairpins to DNA, thus labeling 5'PO4 blunt-ended DNA breaks.
This development exemplifies a new practical approach to the design of molecular machines and provides a useful sensor for detection of apoptosis and DNA damage in fixed cells and tissues.

In vitro Assembly of Semi-artificial Molecular Machine and its Use for Detection of DNA Damage

We demonstrate the assembly and application of a molecular-scale device powered by a topoisomerase protein. The construct is a bio-molecular sensor which labels two major types of DNA breaks in tissue sections by attaching two different fluorophores to their ends.

DNA 손상 감지를위한 세미 인공 분자 기계 및 이용 체외 조립에

Naturally occurring bio-molecular machines work in every living cell and display a variety of designs 1-6. Yet the development of artificial molecular ...

Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians.&#160;Although historically invasive methods have comprised the only means available, the development of noninvasive imaging modalities (echocardiography, MRI, CT) having high temporal and spatial resolution provide a new window for quantitative diastolic function assessment. Echocardiography is the agreed upon standard for diastolic function assessment, but indexes in current clinical use merely utilize selected features of chamber dimension (M-mode) or blood/tissue motion (Doppler) waveforms without incorporating the physiologic causal determinants of the motion itself.&#160;The recognition that all left ventricles (LV) initiate filling by serving as mechanical suction pumps allows global diastolic function to be assessed based on laws of motion that apply to all chambers. What differentiates one heart from another are the parameters of the equation of motion that governs filling. Accordingly, development of the Parametrized Diastolic Filling (PDF) formalism&#160;has shown that the entire range of clinically observed early transmitral flow (Doppler E-wave) patterns are extremely well fit by the laws of damped oscillatory motion.&#160;This permits analysis of individual E-waves in accordance with a causal mechanism (recoil-initiated suction) that yields three (numerically) unique lumped parameters whose physiologic analogues are chamber stiffness (k), viscoelasticity/relaxation (c), and load (xo).&#160;The recording of transmitral flow (Doppler E-waves) is standard practice in clinical cardiology and, therefore, the echocardiographic recording method is only briefly reviewed. Our focus is on determination of the PDF parameters from routinely recorded E-wave data.&#160;As the highlighted results indicate, once the PDF parameters have been obtained from a suitable number of load varying E-waves, the investigator is free to use the parameters or construct indexes from the parameters (such as stored energy 1/2kxo2, maximum A-V pressure gradient kxo, load independent index of diastolic function, etc.) and select the aspect of physiology or pathophysiology to be quantified.

Accurate, causality-based quantification of global diastolic function has been achieved by kinematic modeling-based analysis of transmitral flow via the Parametrized Diastolic Filling (PDF) formalism. PDF generates unique stiffness, relaxation,&#160;and load parameters and elucidates &#39;new&#39; physiology while providing sensitive and specific indexes of dysfunction.

매개 변수화 이완기 충전 형식주의를 통해 Transmitral 흐름의 운동 학적 모델링 기반의 분석에 의하여 세계적인 이완기 기능의 정량화

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians.&#160;Although historically invasive methods have comprised ...

Microscale Vortex-assisted Electroporator for Sequential Molecular Delivery

Electroporation has received increasing attention in the past years, because it is a very powerful technique for physically introducing non-permeant exogenous molecular probes into cells. This work reports a microfluidic electroporation platform capable of performing multiple molecule delivery to mammalian cells with precise and molecular-dependent parameter control. The system&#8217;s ability to isolate cells with uniform size distribution allows for less variation in electroporation efficiency per given electric field strength; hence enhanced sample viability. Moreover, its process visualization feature allows for observation of the fluorescent molecular uptake process in real-time, which permits prompt molecular delivery parameter adjustments in situ for efficiency enhancement. To show the vast capabilities of the reported platform, macromolecules with different sizes and electrical charges (e.g., Dextran with MW of 3,000 and 70,000 Da) were delivered to metastatic breast cancer cells with high delivery efficiencies (&#62;70%) for all tested molecules. The developed platform has proven its potential for use in the expansion of research fields where on-chip electroporation techniques can be beneficial.

A microfluidic vortex assisted electroporation platform was developed for sequential delivery of multiple molecules into identical cell populations with precise and independent dosage control. The system&#8217;s size based target cell purification step preceding electroporation aided to enhance molecular delivery efficiency and processed cell viability.

마이크로 소용돌이를 이용한 순차 분자 전달을위한 Electroporator을

Electroporation has received increasing attention in the past years, because it is a very powerful technique for physically introducing non-permeant ...

Analyzing Mixing Inhomogeneity in a Microfluidic Device by Microscale Schlieren Technique

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren system is constructed from a Hoffman modulation contrast microscope, which provides easy access to the rear focal plane of the objective lens, by removing the slit plate and replacing the modulator with a knife-edge. The working principle of microscale schlieren technique relies on detecting light deflection caused by variation of refractive index1-3. The deflected light either escapes or is obstructed by the knife-edge to produce a bright or a dark band, respectively. If the refractive index of the mixture varies linearly with its composition, the local change in light intensity in the image plane is proportional to the concentration gradient normal to the optical axis. The micro-schlieren image gives a two-dimensional projection of the disturbed light produced by three-dimensional inhomogeneity.
To accomplish quantitative analysis, we describe a calibration procedure that mixes two fluids in a T-microchannel. We carry out a numerical simulation to obtain the concentration gradient in the T-microchannel that correlates closely with the corresponding micro-schlieren image. By comparison, a relationship between the grayscale readouts of the micro-schlieren image and the concentration gradients presented in a microfluidic device is established. Using this relationship, we are able to analyze the mixing inhomogeneity from associate micro-schlieren image and demonstrate the capability of microscale schlieren technique with measurements in a microfluidic oscillator4. For optically transparent fluids, microscale schlieren technique is an attractive diagnostic tool to provide instantaneous full-field information that retains the three-dimensional features of the mixing process.

Herein, we describe a procedure that employs microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. Through calibration, distribution of concentration gradient can be derived from the micro-schlieren image.

마이크로 스케일 슐 리렌 기술에 의해 미세 유체 소자 믹싱 비균질성 분석

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren ...

Eye Irritation Test (EIT) for Hazard Identification of Eye Irritating Chemicals using Reconstructed Human Cornea-like Epithelial (RhCE) Tissue Model

To comply with the Seventh Amendment to the EU Cosmetics Directive and EU REACH legislation, validated non-animal alternative methods for reliable and accurate assessment of ocular toxicity in man are needed. To address this need, we have developed an eye irritation test (EIT) which utilizes a three dimensional reconstructed human cornea-like epithelial (RhCE) tissue model that is based on normal human cells. The EIT is able to separate ocular&#160;irritants and corrosives (GHS Categories 1 and 2 combined) and those that do not require labeling (GHS No Category). The test utilizes two separate protocols, one designed for liquid chemicals and a second, similar protocol for solid test articles. The EIT prediction model uses a single exposure period (30 min for liquids, 6 hr for solids) and a single tissue viability cut-off (60.0% as determined by the MTT assay). Based on the results for 83 chemicals (44 liquids and 39 solids) EIT achieved 95.5/68.2/ and 81.8% sensitivity/specificity and accuracy (SS&#38;A) for liquids, 100.0/68.4/ and 84.6% SS&#38;A for solids, and 97.6/68.3/ and 83.1% for overall SS&#38;A. The EIT will contribute significantly to classifying the ocular irritation potential of a wide range of liquid and solid chemicals without the use of animals to meet regulatory testing requirements. The EpiOcular EIT method was implemented in 2015 into the OECD Test Guidelines as TG 492.

Eye Irritation Test EIT for Hazard Identification of Eye Irritating Chemicals using Reconstructed Human Cornea-like Epithelial RhCE Tissue Model

We have developed an eye irritation test which utilizes a three dimensional reconstructed human cornea-like epithelial (RhCE) tissue model. The test is able to discriminate between ocular irritant and corrosive materials (GHS Categories 1 and 2 combined) and those that do not require labeling (GHS No Category).

복원 된 인간의 각막 모양의 상피 (RHCE) 조직 모델을 사용하여 눈에 자극성 화학 물질의 위험 식별을위한 눈 자극 시험 (EIT)

To comply with the Seventh Amendment to the EU Cosmetics Directive and EU REACH legislation, validated non-animal alternative methods for reliable and ...

Techniques for the Evolution of Robust Pentose-fermenting Yeast for Bioconversion of Lignocellulose to Ethanol

Lignocellulosic biomass is an abundant, renewable feedstock useful for production of fuel-grade ethanol and other bio-products. Pretreatment and enzyme saccharification processes release sugars that can be fermented by yeast. Traditional industrial yeasts do not ferment xylose (comprising up to 40% of plant sugars) and are not able to function in concentrated hydrolyzates. Concentrated hydrolyzates are needed to support economical ethanol recovery, but they are laden with toxic byproducts generated during pretreatment. While detoxification methods can render hydrolyzates fermentable, they are costly and generate waste disposal liabilities. Here, adaptive evolution and isolation techniques are described and demonstrated to yield derivatives of the native Scheffersomyces stipitis strain NRRL Y-7124 that are able to efficiently convert hydrolyzates to economically recoverable ethanol despite adverse culture conditions. Improved individuals are enriched in an evolving population using multiple selection pressures reliant on natural genetic diversity of the S. stipitis population and mutations induced by exposures to two diverse hydrolyzates, ethanol or UV radiation. Final evolution cultures are dilution plated to harvest predominant isolates, while intermediate populations, frozen in glycerol at various stages of evolution, are enriched on selective media using appropriate stress gradients to recover most promising isolates through dilution plating. Isolates are screened on various hydrolyzate types and ranked using a novel procedure involving dimensionless relative performance index (RPI) transformations of the xylose uptake rate and ethanol yield data. Using the RPI statistical parameter, an overall relative performance average is calculated to rank isolates based on multiple factors, including culture conditions (varying in nutrients and inhibitors) and kinetic characteristics. Through application of these techniques, derivatives of the parent strain had the following improved features in enzyme saccharified hydrolyzates at pH 5-6: reduced initial lag phase preceding growth, reduced diauxic lag during glucose-xylose transition, significantly enhanced fermentation rates, improved ethanol tolerance and accumulation to 40 g/L.

Adaptive evolution and isolation techniques are described and demonstrated to yield derivatives of Scheffersomyces stipitis strain NRRL Y-7124 that are able to rapidly consume hexose and pentose mixed sugars in enzyme saccharified undetoxified hydrolyzates and to accumulate over 40 g/L ethanol.

에탄올에 리그 노 셀룰로즈의 생물에 대한 강력한 펜 토스 발효 효모의 진화를위한 기술

Lignocellulosic biomass is an abundant, renewable feedstock useful for production of fuel-grade ethanol and other bio-products. Pretreatment and enzyme ...

Measuring and Modeling Contractile Drying in Human Stratum Corneum

Stratum corneum (SC) is the most superficial skin layer. Its contact with the external environment means that this tissue layer is subjected to both cleansing agents and daily variations in ambient moisture; both of which can alter the water content of the tissue. Reductions in water content from severe barrier dysfunction or low humidity environments can alter SC stiffness and cause a build-up of drying stresses. In extreme conditions, these factors can cause mechanical rupture of the tissue. We have established a high throughput method of quantifying dynamic changes in the mechanical properties of SC upon drying. This technique can be employed to quantify changes in the drying behavior and mechanical properties of SC with cosmetic cleanser and moisturizer treatments. This is achieved by measuring dynamic variations in spatially resolved in-plane drying displacements of circular tissue samples adhered to an elastomer substrate. In-plane radial displacements acquired during drying are azimuthally averaged and fitted with a profile based on a linear elastic contractility model. Dynamic changes in drying stress and SC elastic modulus can then be extracted from the fitted model profiles.

This article describes a method of quantifying the dynamic drying behavior and mechanical properties of stratum corneum by measuring spatially resolved in-plane drying displacements of circular tissue samples adhered to an elastomer substrate. This technique can be used to measure how different chemical treatments alter drying and tissue mechanical properties.

측정 및 모델링 수축성 건조 인간의 각질층에

Stratum corneum (SC) is the most superficial skin layer. Its contact with the external environment means that this tissue layer is subjected to both ...

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and dampen loads in the spine. The IVD consists of a proteoglycan-rich nucleus pulposus (NP) and a collagen-rich annulus fibrosis (AF) sandwiched by cartilaginous end-plates. Together with the adjacent vertebrae, the vertebrae-IVD structure forms a functional spine unit (FSU). These microstructures contain unique cell types as well as unique extracellular matrices. Whole organ culture of the FSU preserves the native extracellular matrix, cell differentiation phenotypes, and cellular-matrix interactions. Thus, organ culture techniques are particularly useful for investigating the complex biological mechanisms of the IVD. Here, we describe a high-throughput approach for culturing whole lumbar mouse FSUs that provides an ideal platform for studying disease mechanisms and therapies for the IVD. Furthermore, we describe several applications that utilize this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution finite element modeling of the IVD.

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix interactions. Here we describe an IVD culture system using mouse lumbar and caudal IVDs in their functional spinal units and several applications utilizing this system.

<em&gt; 체외</em쥐의 추간판의&gt; 장기 문화 모델

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

Advanced 3D Liver Models for In vitro Genotoxicity Testing Following Long-Term Nanomaterial Exposure

Due to the rapid development and implementation of a diverse array of engineered nanomaterials (ENM), exposure to ENM is inevitable and the development of robust, predictive in vitro test systems is essential. Hepatic toxicology is key when considering ENM exposure, as the liver serves a vital role in metabolic homeostasis and detoxification as well as being a major site of ENM accumulation post exposure. Based upon this and the accepted understanding that 2D hepatocyte models do not accurately mimic the complexities of intricate multi-cellular interactions and metabolic activity observed in vivo, there is a greater focus on the development of physiologically relevant 3D liver models tailored for ENM hazard assessment purposes in vitro. In line with the principles of the 3Rs to replace, reduce and refine animal experimentation, a 3D HepG2 cell-line based liver model has been developed, which is a user friendly, cost effective system that can support both extended and repeated ENM exposure regimes (&#8804;14 days). These spheroid models (&#8805;500 &#181;m in diameter) retain their proliferative capacity (i.e., dividing cell models) allowing them to be coupled with the &#8216;gold standard&#8217; micronucleus assay to effectively assess genotoxicity in vitro. Their ability to report on a range of toxicological endpoints (e.g., liver function, (pro-)inflammatory response, cytotoxicity and genotoxicity) has been characterized using several ENMs across both acute (24 h) and long-term (120 h) exposure regimes. This 3D in vitro hepatic model has the capacity to be utilized for evaluating more realistic ENM exposures, thereby providing a future in vitro approach to better support ENM hazard assessment in a routine and easily accessible manner.

This procedure was established to be used for developing advanced 3D hepatic cultures in vitro, which can provide a more physiologically relevant assessment of the genotoxic hazards associated with nanomaterial exposures over both an acute or long-term, repeated dose regimes.

장기 나노 물질 노출 다음 체외 물질 독성 테스트를 위한 고급 3D 간 모델

Due to the rapid development and implementation of a diverse array of engineered nanomaterials (ENM), exposure to ENM is inevitable and the development of ...