여기에 포함 된 일부 수치는 저작권 허가 센터의 허가에 의해 적응되었습니다 : 스프링어 자연, 생물 의학 공학의 연보. 라이브 현미경 이미징을 가능하게하면서 균일 한 z 축 균주를 가진 3D 하이드로겔을 긴장, A. Roitblat 리바, S. 나탄, A. 콜렐, H. Rushkin, O. Tchaicheeyan, A. Lesman, 저작권© (2019).
https://doi.org/10.1007/s10439-019-02426-7

저자는 공개 할 것이 없습니다.

본 원에 제시된 방법 및 프로토콜은 주로 Roitblat Riba 외.41에 의한 이전 연구를 기반으로 하며, 여기에 SCyUS 장치의 전체 컴퓨터 지원 설계(CAD), 파이썬 및 마이크로 컨트롤러 코드를 포함합니다.
기존 접근법에 비해 제시된 방법의 주요 장점은 매우 부드러운 3D 하이드로겔(+100 Pa의 탄성 계수)을 둘레에서, 그리고 살아있는 공초점 이미징하에서 변?...

기계적 힘에 대한 조직 반응은 유전자 발현1,세포 분화2및 조직 리모델링3을포함하는 광범위한 생물학적 기능의 필수적인 부분이다. 더욱이, 섬유 정렬 및 밀도와 같은 세포외 매트릭스(ECM)의 강제 유도 된 변화는 세포 거동 및 조직형성에영향을 미칠 수 있습니다4,5,6. ECM의 섬유질 메쉬 구조는 비선형 탄성, 비미세 변형 및 플라스틱 변형7,8,9,10,11,12와같은 흥미로운 기계적 특성을 갖는다. 이러한 특성은 세포와 주변 미세 환경이 외부 기계적힘(13,14)에어떻게반응하는지에영향을 미칩니다. ECM과 조직이 기계적 힘에 어떻게 반응하는지 이해하면 조직 공학 분야와 보다 정확한 전산 및 이론적 모델 의 개발에서 진전을 이룰 수 있습니다.
기계적으로 샘플을 스트레칭하는 가장 일반적인 방법은 세포 거동에 미치는 영향을 탐구하기 위해 세포가 풍부한 2D 기판에 초점을 맞추고있다. 이들은 예를 들어, 폴리디메틸실록산(PDMS) 기판에 균주를 적용하고 스트레치방향(15,16,17,18,19)과관련하여 세포 배향 각도를 분석한다. 그러나, 외부 스트레치에 3D 세포 임베디드 하이드로겔의 반응을 조사하는 방법은 조직 미세 환경을 보다 밀접하게 모방하는 상황이더 제한적이다. 3D 스트레칭 방법을 향한 어드밴스는 세포가 3D행렬(20)과비교할 때 2D 기판에서 다르게 행동하기 때문에 특히 중요합니다. 이러한 거동은 세포 재조정, 단백질 발현 수준 및 이동패턴(21,22,23)을포함한다.
3D 샘플 스트레칭을허용하는 방법 및 장치는24, 25, 26,27,28 및 실험실 연구를 위해 개발된29개모두를 포함한다. 이들 방법은 분해성 실리콘튜브(30),다중웰 챔버31개,클램프26,32,생물반응기11,33,캔틸레버34,35,36,및 자석37,38을사용한다. 일부 기술은 젤5의두 단일 지점에서 바늘을 당겨서 3D 하이드로겔을 국소 변형시키는 스트레치를 생성하고, 다른 기술은겔(16)의전체 대량의 변형을 허용한다. 더욱이, 이러한 시스템의 대부분은 Z-방향의스트레인 필드에 대한 제한된 정보와 함께 X-Y 평면에서 스트레인 필드의 분석에 초점을 맞춥니다. 추가적으로, 이 장치의 소수만이 시투 화상 진찰에 있는 현미경을 할 수 있습니다. 시상 고배율 이미징(예: 공초점 현미경)의 주요 과제는 객관적인 렌즈에서 샘플까지 수백 미크론의 제한된 작업 거리입니다. 스트레치 중에 라이브 이미징을 허용하는 장치는 Z축에서 균주의 균일성을 희생하거나 상대적으로 복잡하고 다른 실험실에서 재현하기 어려운39,40.
스트레치 3D 하이드로겔에 대한 이 접근법은 살아있는 공초점 현미경 검사관 동안 정적 또는 주기적 원색 균주를 허용합니다. 스트레칭 장치('스마트 순환 동종 들것 - SCyUS'라고 함)는 3D 인쇄 부품과 저비용 하드웨어를 사용하여 제작되어 다른 실험실에서 쉽게 재현할 수 있습니다. 장치에 부착된 것은 중앙에 기하학적 컷아웃이 있는 시판되는 실리콘 고무입니다. 하이드로겔 성분은 컷아웃을 채우기 위해 중합된다. 중합 화 하는 동안, 생물 하이드로 겔, 피브린 또는 콜라겐 등, 자연스럽 게 컷 아웃의 내부 벽에 부착. SCyUS를 사용하여 실리콘 스트립은 단원하게 뻗어 임베디드 3D하이드로겔(41)으로제어된 균주를 이송한다.
이 시스템은 다른 기존 방법에 비해 기능과 장점의 독특한 조합을 할 수 있습니다. 첫째, 이 시스템은 하이드로겔 전체에 걸쳐 Z-균질변형과 함께 주변에서 두꺼운 3D 소프트 하이드로겔(>100 μm 두께, <1 kPa 강성)의 단방향 스트레칭을 허용합니다. 이러한 하이드로겔은 기존의 인장 기술에 의해 잡히고 뻗어 너무 부드럽습니다. 둘째, 3D 프린팅은 연구원이 쉽게 사용할 수 있고 설계에 사용되는 전자 장치가 저렴한 비용으로 사용되기 때문에 스트레치 장치는 다른 실험실에서 쉽게 복제 될 수 있습니다. 셋째, 아마도 가장 매력적인 기능, 실리콘 스트립에서 컷아웃의 형상 및 크기는 쉽게 조작할 수 있어, 튜닝 가능한 스트레인 그라데이션 및 경계 조건뿐만 아니라 다양한 샘플 볼륨을 몇 마이크로리터까지 사용할 수 있습니다.
제시된 프로토콜은 라이브 공초점 현미경 검사의 밑에 uniaxial 스트레치에 의해 진행된 0.5 mm 두께의 실리콘 고무 스트립에 있는 ~2mm 직경 디스크로 성형 피브린 젤로 이루어져 있습니다. 다음은 기하학적 컷아웃에 작용하는 균주를 측정하고 분석하기 위한 실험 절차, 하이드로겔에서 개발된 내부 균주, 다양한 스트레치 조작 후의 결과 섬유 정렬에 대해 자세히 설명합니다. 마지막으로, 하이드로겔에 세포를 포함하고 통제된 외부 스트레치에 노출시킬 가능성에 대해 논의된다.

<table>
	<tbody>
		<tr>
			<td>Alexa Fluor 546 carboxylic acid, succinimidyl ester</td>
			<td>Invitrogen</td>
			<td>A20002</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Medium (DMEM High Glucose)</td>
			<td>Biological Industries</td>
			<td>01-052-1A</td>
			<td>Add 10% FBS, 1% PNS, 1% L-Glutamine, 1% Sodium Pyruvate</td>
		</tr>
		<tr>
			<td>Cover Slip #1.5</td>
			<td>Bar-Naor Ltd.</td>
			<td>BN72204-30</td>
			<td>22&#215;40 mm</td>
		</tr>
		<tr>
			<td>DIMETHYL SULPHOXIDE 99.5% GC DMSO</td>
			<td>Sigma-Aldrich Inc.</td>
			<td>D-5879-500 ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Phosphate-Buffered Saline</td>
			<td>Biological Industries</td>
			<td>02-023-1A</td>
			<td></td>
		</tr>
		<tr>
			<td>EVICEL Fibrin Sealant (Human)</td>
			<td>Omrix Biopharmaceuticals</td>
			<td>3902</td>
			<td>Fibrinogen: 70 mg/mL, Thrombin: 800-1200 IU/mL</td>
		</tr>
		<tr>
			<td>Fibrinogen Buffer</td>
			<td>N/A</td>
			<td></td>
			<td>Recipe for 1L: 7g NaCl, 2.94g trisodium citrate dihydrate, 9g glycine, 20g arginine hydrochloride &#38; 0.15g calcium chloride dihydrate. Bring final volume to 1L with PuW (pH 7.0-7.2)</td>
		</tr>
		<tr>
			<td>Fluorescent micro-beads FluoSpheres (1 &#181;m)</td>
			<td>Invitrogen</td>
			<td>F8820</td>
			<td>Orange (540/560) 
			Provided as suspension (2% solids) in water plus 2 mM sodium azide</td>
		</tr>
		<tr>
			<td>High-Temperature Silicone Rubber</td>
			<td>McMaster-Carr</td>
			<td>3788T41</td>
			<td>580 &#181;m-thick 
			E = 1.5 Mpa 
			Poisson Ratio = 0.48 
			Tensile Strength = 4.8 MPa 
			Upper limit of stretch = +300% engineering strain</td>
		</tr>
		<tr>
			<td>HiTrap desalting column 5 mL (Sephadex G-25 packed)</td>
			<td>GE Healthcare</td>
			<td>17-1408-01</td>
			<td></td>
		</tr>
		<tr>
			<td>HIVAC-G High Vacuum Sealing Compound</td>
			<td>Shin-Etsu Chemical Co., Ltd.</td>
			<td>HIVAC-G 100</td>
			<td></td>
		</tr>
		<tr>
			<td>ImageJ FIJI software39</td>
			<td>National Institute of Health, Bethesda, MD</td>
			<td>Version 1.8.0_112</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcontroller (Adruino Uno + Adafruit Motorshield v2.3)</td>
			<td>Arduino/Adafruit</td>
			<td>Arduino-DK001/Adafruit-1438</td>
			<td></td>
		</tr>
		<tr>
			<td>MicroVL 21R Centrifuge</td>
			<td>Thermo Scientific</td>
			<td>75002470</td>
			<td></td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>Bemis</td>
			<td>PM-996</td>
			<td></td>
		</tr>
		<tr>
			<td>Primovert Light Microscope</td>
			<td>Carl Zeiss Suzhou Co., Ltd.</td>
			<td>491206-0011-000</td>
			<td></td>
		</tr>
		<tr>
			<td>SCyUS CAD (Solidworks)</td>
			<td>Dassault Syst&#232;mes</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>SCyUS Code37</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Servomotor - TowerPro SG-5010</td>
			<td>Adafruit</td>
			<td>155</td>
			<td></td>
		</tr>
		<tr>
			<td>SL 16R Centrifuge</td>
			<td>Thermo Scientific</td>
			<td>75004030</td>
			<td>For 50 mL tubes</td>
		</tr>
		<tr>
			<td>Sterile 10 cm non-culture plates</td>
			<td>Corning</td>
			<td>430167</td>
			<td></td>
		</tr>
		<tr>
			<td>Thrombin buffer</td>
			<td>N/A</td>
			<td></td>
			<td>Recipe for 1L: 20g mannitol, 8.77g NaCl, 2.72g sodium acetate trihydrate, 24 mL 25% Human Serum Albumin, 5.88g calcium chloride. Bring final volume to 1L with PuW (pH 7.0)</td>
		</tr>
		<tr>
			<td>Trypsin EDTA Solution B (0.25%), EDTA (0.05%)</td>
			<td>Biological Industries</td>
			<td>03-052-1B</td>
			<td></td>
		</tr>
		<tr>
			<td>USB Cable (Type B Male to Type A Male)</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Zeiss LSM 880 Confocal Microscope</td>
			<td>Carl Zeiss AG</td>
			<td>2811000417</td>
			<td></td>
		</tr>
		<tr>
			<td>ZEN 2.3 SP1 FP3 (black)</td>
			<td>Carl Zeiss AG</td>
			<td>Release Version 14.0.0.0</td>
			<td></td>
		</tr>
	</tbody>
</table>

controlled strain of 3d hydrogels under live microscopy imaging

외부 힘은 조직 형성, 발달 및 유지 보수에 중요한 요소입니다. 이러한 힘의 효과 종종 시험 관 스트레칭 방법을 전문 사용 하 여 공부. 다양한 사용 가능한 시스템은 2D 기판 기반 들것을 사용하는 반면, 3D 기술의 접근성은 부드러운 하이드로겔을 변형시키는 데 더 제한적입니다. 여기서는 탄성 실리콘 스트립을 샘플 캐리어로 사용하여 둘레에서 부드러운 하이드로겔의 외부 스트레칭을 허용하는 방법을 설명합니다. 이 프로토콜에 활용되는 스트레칭 시스템은 3D 인쇄 부품과 저비용 전자 장치로 구성되므로 다른 실험실에서 간단하고 쉽게 복제할 수 있습니다. 실험 공정은 실리콘 스트립의 중앙에 컷아웃에서 두꺼운(>100 μm) 소프트 피브린 하이드로겔(탄성 계수 ~100Pa)을 중합하는 것으로 시작됩니다. 그런 다음 실리콘 겔 구조는 인쇄 된 스트레칭 장치에 부착되고 공초점 현미경 단계에 배치됩니다. 살아있는 현미경 검사에서 스트레칭 장치가 활성화되고 겔은 다양한 스트레치 크기로 이미지됩니다. 영상 처리는 젤의 3D 두께(Z-축)에 걸쳐 상대적으로 균일한 균질균및 섬유 정렬을입증하여 생성된 겔 변형을 정량화하는 데 사용됩니다. 이 방법의 장점은 시투 현미경 검사법에서 실행하는 동안 3D에서 매우 부드러운 하이드로겔을 변형시키는 능력과 사용자의 요구에 따라 샘플의 형상 및 크기를 조작 할 수있는 자유를 포함한다. 또한, 적절한 적응을 통해, 이 방법은 다른 유형의 하이드로겔(예를 들어, 콜라겐, 폴리아크릴라미드 또는 폴리에틸렌 글리콜)을 스트레칭하는 데 사용될 수 있으며, 더 많은 생체 모방 3D 조건 하에서 외부 력에 대한 세포 및 조직 반응의 분석을 허용할 수 있다.

1 μm 형광 구슬이 내장된 3D 피브린 하이드로겔을 운반하는 실리콘 스트립에 가해지는 증가 크기의 정적 스트레치로부터의 대표적인 데이터가 도 9에도시된다. 이 분석은 실리콘 스트레치가 절단의 기하학적 변화뿐만 아니라 젤 내의 개발 된 균주에 미치는 영향을 보여줍니다. 전체 젤의 Z-스택이미지는 타원형형상(도 9A)에컷아웃된 원래 ?...

Watch this Scientific Journal Video about Controlled Strain of 3D Hydrogels under Live Microscopy Imaging at JoVE.com

Controlled Strain of 3D Hydrogels under Live Microscopy Imaging

제시된 방법은 실리콘 고무에 내장된 3D 소프트 하이드로겔의 단종 스트레칭을 포함하면서 살아있는 공초점 현미경 검사를 허용합니다. 섬유 정렬뿐만 아니라 외부 및 내부 하이드로겔 균주의 특성화가 입증된다. 개발된 장치 및 프로토콜은 다양한 변형 정권에 대한 세포의 반응을 평가할 수 있다.

라이브 현미경 이미징 에서 3D 하이드로겔의 제어 변형

External forces are an important factor in tissue formation, development, and maintenance. The effects of these forces are often studied using specialized ...

controlled-strain-of-3d-hydrogels-under-live-microscopy-imaging

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JoVE Journal

Bioengineering

3.4K 조회수.  Tel-Aviv University. 제시된 방법은 실리콘 고무에 내장된 3D 소프트 하이드로겔의 단종 스트레칭을 포함하면서 살아있는 공초점 현미경 검사를 허용합니다. 섬유 정렬뿐만 아니라 외부 및 내부 하이드로겔 균주의 특성화가 입증된다. 개발된 장치 및 프로토콜은 다양한 변형 정권에 대한 세포의 반응을 평가할 수 있다.

비디오: Controlled Strain of 3D Hydrogels under Live Microscopy Imaging

Three-dimensional Optical-resolution Photoacoustic Microscopy

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. 
The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM)1, where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular2 level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy3 or with optical-scattering-based OCT4 (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. 
Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology5, 6, ophthalmology7, 8, vascular biology9, and dermatology10. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.

입체 광학 해상도 Photoacoustic 현미경

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As ...

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생체공학

Magnetically-Assisted Remote Controlled Microcatheter Tip Deflection under Magnetic Resonance Imaging

X-ray fluoroscopy-guided endovascular procedures have several significant limitations, including difficult catheter navigation and use of ionizing radiation, which can potentially be overcome using a magnetically steerable catheter under MR guidance.
	The main goal of this work is to develop a microcatheter whose tip can be remotely controlled using the magnetic field of the MR scanner. This protocol aims to describe the procedures for applying current to the microcoil-tipped microcatheter to produce consistent and controllable deflections.
	A microcoil was fabricated using laser lathe lithography onto a polyimide-tipped endovascular catheter. In vitro testing was performed in a waterbath and vessel phantom under the guidance of a 1.5-T MR system using steady-state free precession (SSFP) sequencing. Various amounts of current were applied to the coils of the microcatheter to produce measureable tip deflections and navigate in vascular phantoms.
	The development of this device provides a platform for future testing and opportunity to revolutionize the endovascular interventional MRI environment.

Current applied to an endovascular microcatheter with microcoil tip made by laser lathe lithography can achieve controllable deflections under magnetic resonance (MR) guidance, which may improve speed and efficacy of navigation of vasculature during various endovascular procedures.

자기 공명 영상 아래에 자기 (磁 气)를 이용한 원격 제어 Microcatheter 팁 편향

X-ray fluoroscopy-guided  endovascular procedures have several significant limitations, including  difficult catheter navigation and use of ionizing ...

Tunable Hydrogels from Pulmonary Extracellular Matrix for 3D Cell Culture

Here we present a method for establishing multiple component cell culture hydrogels for in vitro lung cell culture. Beginning with healthy en bloc lung tissue from porcine, rat, or mouse, the tissue is perfused and submerged in subsequent chemical detergents to remove the cellular debris. Histological comparison of the tissue before and after processing confirms removal of over 95% of double stranded DNA and alpha galactosidase staining suggests the majority of cellular debris is removed. After decellularization, the tissue is lyophilized and then cryomilled into a powder. The matrix powder is digested for 48 hr in an acidic pepsin digestion solution and then neutralized to form the pregel solution. Gelation of the pregel solution can be induced by incubation at 37 &#176;C and can be used immediately following neutralization or stored at 4 &#176;C for up to two weeks. Coatings can be formed using the pregel solution on a non-treated plate for cell attachment. Cells can be suspended in the pregel prior to self-assembly to achieve a 3D culture, plated on the surface of a formed gel from which the cells can migrate through the scaffold, or plated on the coatings. Alterations to the strategy presented can impact gelation temperature, strength, or protein fragment sizes. Beyond hydrogel formation, the hydrogel stiffness may be increased using genipin.

This is a method to create a 3-dimensional cell culture scaffold from pulmonary extracellular matrix. Intact lung is processed into hydrogels that can support the growth of cells in three-dimensions.

3 차원 세포 배양을위한 폐 세포 외 매트릭스에서 조정 히드로 겔

Here we present a method for establishing multiple component cell culture hydrogels for in vitro lung cell culture. Beginning with healthy en bloc lung ...

Production of Elastin-like Protein Hydrogels for Encapsulation and Immunostaining of Cells in 3D

Two-dimensional (2D) tissue culture techniques have been essential for our understanding of fundamental cell biology. However, traditional 2D tissue culture systems lack a three-dimensional (3D) matrix, resulting in a significant disconnect between results collected in vitro and in vivo. To address this limitation, researchers have engineered 3D hydrogel tissue culture platforms that can mimic the biochemical and biophysical properties of the in vivo cell microenvironment. This research has motivated the need to develop material platforms that support 3D cell encapsulation and downstream biochemical assays. Recombinant protein engineering offers a unique toolset for 3D hydrogel material design and development by allowing for the specific control of protein sequence and therefore, by extension, the potential mechanical and biochemical properties of the resultant matrix. Here, we present a protocol for the expression of recombinantly-derived elastin-like protein (ELP), which can be used to form hydrogels with independently tunable mechanical properties and cell-adhesive ligand concentration. We further present a methodology for cell encapsulation within ELP hydrogels and subsequent immunofluorescent staining of embedded cells for downstream analysis and quantification.

Recombinant protein-engineered hydrogels are advantageous for 3D cell culture as they allow for complete tunability of the polymer backbone and therefore, the cell microenvironment. Here, we describe the process of recombinant elastin-like protein purification and its application in 3D hydrogel cell encapsulation.

캡슐화 및 3d에서 셀의 Immunostaining에 대 한 엘라 스 틴 같은 단백질 Hydrogels의 생산

Two-dimensional (2D) tissue culture techniques have been essential for our understanding of fundamental cell biology. However, traditional 2D tissue ...

Visualizing Adhesion Formation in Cells by Means of Advanced Spinning Disk-Total Internal Reflection Fluorescence Microscopy

In living cells, processes such as adhesion formation involve extensive structural changes in the plasma membrane and the cell interior. In order to visualize these highly dynamic events, two complementary light microscopy techniques that allow fast imaging of live samples were combined: spinning disk microscopy (SD) for fast and high-resolution volume recording and total internal reflection fluorescence (TIRF) microscopy for precise localization and visualization of the plasma membrane. A comprehensive and complete imaging protocol will be shown for guiding through sample preparation, microscope calibration, image formation and acquisition, resulting in multi-color SD-TIRF live imaging series with high spatio-temporal resolution. All necessary image post-processing steps to generate multi-dimensional live imaging datasets, i.e. registration and combination of the individual channels, are provided in a self-written macro for the open source software ImageJ. The imaging of fluorescent proteins during initiation and maturation of adhesion complexes, as well as the formation of the actin cytoskeletal network, was used as a proof of principle for this novel approach. The combination of high resolution 3D microscopy and TIRF provided a detailed description of these complex processes within the cellular environment and, at the same time, precise localization of the membrane-associated molecules detected with a high signal-to-background ratio.

An advanced microscope that permit fast and high-resolution imaging of both, the isolated plasma membrane and the surrounding intracellular volume, will be presented. The integration of spinning disk and total internal reflection fluorescence microscopy in one setup allows live imaging experiments at high acquisition rates up to 3.5 s per image stack.

회전 디스크-총 내부 반사 형광 현미경 검사 법 고급 시각화에 의해 세포 접착 형성

In living cells, processes such as adhesion formation involve extensive structural changes in the plasma membrane and the cell interior. In order to ...

Measuring Global Cellular Matrix Metalloproteinase and Metabolic Activity in 3D Hydrogels

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) culture systems. However, measurement of cell function in 3D culture is often more challenging. Many biological assays require retrieval of cellular material which can be difficult in 3D cultures. One way to address this challenge is to develop new materials that enable measurement of cell function within the material. Here, a method is presented for measurement of cellular matrix metalloproteinase (MMP) activity in 3D hydrogels in a 96-well format. In this system, a poly(ethylene glycol) (PEG) hydrogel is functionalized with a fluorogenic MMP cleavable sensor. Cellular MMP activity is proportional to fluorescence intensity and can be measured with a standard microplate reader. Miniaturization of this assay to a 96-well format reduced the time required for experimental set up by 50% and reagent usage by 80% per condition as compared to the previous 24-well version of the assay. This assay is also compatible with other measurements of cellular function. For example, a metabolic activity assay is demonstrated here, which can be conducted simultaneously with MMP activity measurements within the same hydrogel. The assay is demonstrated with human melanoma cells encapsulated across a range of cell seeding densities to determine the appropriate encapsulation density for the working range of the assay. After 24 h of cell encapsulation, MMP and metabolic activity readouts were proportional to cell seeding density. While the assay is demonstrated here with one fluorogenic degradable substrate, the assay and methodology could be adapted for a wide variety of hydrogel systems and other fluorescent sensors. Such an assay provides a practical, efficient and easily accessible 3D culturing platform for a wide variety of applications.

Here, a protocol is presented for encapsulating and culturing cells in poly(ethylene glycol) (PEG) hydrogels functionalized with a fluorogenic matrix metalloproteinase (MMP)-degradable peptide. Cellular MMP and metabolic activity are measured directly from the hydrogel cultures using a standard microplate reader.

글로벌 세포 매트릭스 Metalloproteinase 및 3D Hydrogels 신진 대사 활동 측정

Three-dimensional (3D) cell culture systems often more closely recapitulate in vivo cellular responses and functions than traditional two-dimensional (2D) ...

High-resolution Imaging of Nuclear Dynamics in Live Cells under Uniaxial Tensile Strain

Extracellular mechanical strain is known to elicit cell phenotypic responses and has physiological relevance in several tissue systems. To capture the effect of applied extracellular tensile strain on cell populations in vitro via biochemical assays, a device has previously been designed which can be fabricated simply and is small enough to fit inside tissue culture incubators, as well as on top of microscope stages. However, the previous design of the polydimethylsiloxane substratum did not allow high-resolution subcellular imaging via oil-immersion objectives. This work describes a redesigned geometry of the polydimethylsiloxane substratum and a customized imaging setup that together can facilitate high-resolution subcellular imaging of live cells while under applied strain. This substratum can be used with the same, earlier designed device and, hence, has the same advantages as listed above, in addition to allowing high-resolution optical imaging. The design of the polydimethylsiloxane substratum can be improved by incorporating a grid which will facilitate tracking the same cell before and after the application of strain. Representative results demonstrate high-resolution time-lapse imaging of fluorescently labeled nuclei within strained cells captured using the method described here. These nuclear dynamics data give insights into the mechanism by which applied tensile strain promotes differentiation of oligodendrocyte progenitor cells.&#160;

Using a previously designed device to apply mechanical strain to adherent cells, this paper describes a redesigned substratum geometry and a customized apparatus for high-resolution single-cell imaging of strained cells with a 100x oil immersion objective.

일축 인장 스트레인 하에서 살아있는 세포의 핵 역학에 대 한 고해상도 이미징

Extracellular mechanical strain is known to elicit cell phenotypic responses and has physiological relevance in several tissue systems. To capture the ...

A Custom Multiphoton Microscopy Platform for Live Imaging of Mouse Cornea and Conjunctiva

Conventional histological analysis and cell culture systems are insufficient to simulate in vivo physiological and pathological dynamics completely. Multiphoton microscopy (MPM) has become one of the most popular imaging modalities for biomedical study at cellular levels in vivo, advantages include high resolution, deep tissue penetration and minimal phototoxicity. We have designed an MPM imaging platform with a customized mouse eye holder and a stereotaxic stage for imaging ocular surface in vivo. Dual fluorescent protein reporter mouse enables visualization of cell nuclei, cell membranes, nerve fibers, and capillaries within the ocular surface. In addition to multiphoton fluorescence signals, acquiring second harmonic generation (SHG) simultaneously allows for the characterization of collagenous stromal architecture. This platform can be employed for intravital imaging with accurate positioning across the entire ocular surface, including cornea and conjunctiva.

Presented here is a multiphoton microscopic platform for live mouse ocular surface imaging. Fluorescent transgenic mouse enables the visualization of cell nuclei, cell membranes, nerve fibers and capillaries within the ocular surface. Non-linear second harmonic generation signals derived from collagenous structures provide label-free imaging for stromal architectures.

마우스 각막과 결막의 라이브 이미징을 위한 맞춤형 다광현미경 플랫폼

Conventional histological analysis and cell culture systems are insufficient to simulate in vivo physiological and pathological dynamics completely. ...

A Flexible Chamber for Time-Lapse Live-Cell Imaging with Stimulated Raman Scattering Microscopy

Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology. Live-cell imaging with SRS has been demonstrated for many biological and biomedical applications. However, long-term time-lapse SRS imaging of live cells has not been widely adopted. SRS microscopy often uses a high numerical aperture (NA) water-immersion objective and a high NA oil-immersion condenser to achieve high-resolution imaging. In this case, the gap between the objective and the condenser is only a few millimeters. Therefore, most commercial stage-top environmental chambers cannot be used for SRS imaging because of their large thickness with a rigid glass cover. This paper describes the design and fabrication of a flexible chamber that can be used for time-lapse live-cell imaging with transmitted SRS signal detection on an upright microscope frame. The flexibility of the chamber is achieved by using a soft material - a thin natural rubber film. The new enclosure and chamber design can be easily added to an existing SRS imaging setup. The testing and preliminary results demonstrate that the flexible chamber system enables stable, long-term, time-lapse SRS imaging of live cells, which can be used for various bioimaging applications in the future.

We report a stage-top, flexible environmental chamber for time-lapse imaging of live cells using upright stimulated Raman scattering microscopy with transmitted signal detection. Lipid droplets were imaged in SKOV3 cells treated with oleic acid for up to 24 h with a 3 min time interval.

자극 라만 산란 현미경을 사용한 타임랩스 라이브 셀 이미징을 위한 유연한 챔버

Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology. Live-cell imaging with SRS has been demonstrated for many ...

Microengineering 3D Collagen Hydrogels with Long-Range Fiber Alignment

Aligned collagen I (COL1) fibers guide tumor cell motility, influence endothelial cell morphology, control stem cell differentiation, and are a hallmark of cardiac and musculoskeletal tissues. To study cell response to aligned microenvironments in vitro, several protocols have been developed to generate COL1 matrices with defined fiber alignment, including magnetic, mechanical, cell-based, and microfluidic methods. Of these, microfluidic approaches offer advanced capabilities such as accurate control over fluid flows and the cellular microenvironment. However, the microfluidic approaches to generate aligned COL1 matrices for advanced in vitro culture platforms have been limited to thin "mats" (&lt;40 &#181;m in thickness) of COL1 fibers that extend over distances less than 500 &#181;m and are not conducive to 3D cell culture applications. Here, we present a protocol to fabricate 3D COL1 matrices (130-250 &#181;m in thickness) with millimeter-scale regions of defined fiber alignment in a microfluidic device. This platform provides advanced cell culture capabilities to model structured tissue microenvironments by providing direct access to the micro-engineered matrix for cell culture.

This protocol demonstrates the use of a microfluidic channel with changing geometry along the fluid flow direction to generate extensional strain (stretching) to align fibers in a 3D collagen hydrogel (&lt;250 &#181;m in thickness). The resulting alignment extends across several millimeters and is influenced by the extensional strain rate.

Microengineering 3D 콜라겐 하이드로겔(장거리 섬유 정렬 포함)

Aligned collagen I (COL1) fibers guide tumor cell motility, influence endothelial cell morphology, control stem cell differentiation, and are a hallmark ...