This work was supported by the National Institutes of Health (R01-EB014496). The authors would like to thank Iason Apostolakis for his contribution to the experiments.

이 프로토콜은 컬럼비아 대학의 기관 동물 케어 및 사용위원회에 의해 승인되었다. 모든 데이터 수집 및 처리 매트랩 환경을 사용하여 수행 하였다. 1. 실험 장치 <ol><li> 90 분 동안 생체 개 간 샘플을 드가. 탈기 인산염 완충 용액 (그림 1)로 채워진 탱크에 간 샘플을 넣습니다. 간 사지에서 바늘 음향 흡수에 간 샘플을 수정합니다. </li><li> 4.5 MHz의 중심 주파수, 70mm 초점 깊이로 (치료) (93) 요소 반구 배열 HIFU 변환기의 중앙에 위치한 원형의 구멍을 통해 64 소자, 0.32 mm 피치, 2.5 MHz의 중심 주파수 위상 어레이 (촬상)를 삽입 1.7 mm X 0.4 mm의 초점 크기 (11). 동축 모두 트랜스 듀서를 맞추고 조정 나사와 치료 변환기에 영상 변환기를 고정합니다. <ol><li> AV와 HIFU 변환기를 덮그것을 아래로 냉각 탈기 흐르는 물 가득 폴리 우레탄 막을 olume 제어. 컴퓨터로 제어되는 3 차원 포지셔너의 트랜스 듀서 어셈블리를 장착합니다. </li></ol></li><li> 500 MV 최대 진폭과 25 Hz의 진폭 변조 된 사인 파형을 보내는 함수 발생기에 HIFU 변환기를 연결합니다. 소프트웨어를 사용 matlab에 완전히 프로그램 초음파 시스템에 촬상 변환기를 연결한다. 초음파 시스템과 관련된 소프트웨어 및 매트랩 환경을 사용하는 시스템에 연결된 컴퓨터에 설치되어야한다 : 주. 50dB 증폭기 및 RF 정합 네트워크는 HIFU 변환기 각각 전력을 증폭하고 임피던스에 맞도록 함수 발생기 사이에 배치되어야한다. </li><li> 이는 원점 128 라인과 방위각 방향으로 9.625 ㎛ 내지 90 °의 공간적 단계와 반경 방향으로 깊은 어레이의 표면으로부터 50mm 및 40mm 개시 매트랩을 사용하여, 극성 그리드 만들기 FO 인발산 파의 기분이야. 어레이의 표면 뒤에 발산 파 10.24 mm의 소스 (구멍 크기의 절반)을 정의하고, 가로 방향 중심. <ol><li> 넓은 평면파 64 라인 폭 방향 9.625 ㎛ 내지 20mm의 공간 단계와 축 방향으로 깊게 배열의 표면으로부터 50mm 및 40mm 개시 매트랩을 사용하여 직교 표를 작성. 어레이의 표면에서 평면파의 소스를 정의한다. 각 격자에 대해, 다시 배열의 각 요소에 각각의 그리드 지점 소스로부터 시간을 계산하고. </li></ol></li><li> matlab에 명령 창에서 평면파 이미징 웨이브 영상 또는 &quot;ReconMat_PW&quot;를 발산은 &quot;ReconMat_DW&quot;을 입력하고 각 격자에 대한 표준 지연과 합 알고리즘과 관련된 재건 행렬을 작성하려면 &quot;입력&quot;키를 누릅니다. 표준 기준 벡터의 각각에 지연과 합 알고리즘을 적용하고 비 제로의 elemen 검색결과 매트릭스 (11)의 TS. 대응하는 위치에 상기 희소 행렬 생성 행렬로부터 얻어진 비 - 제로 엘리먼트를 할당. 컴퓨터 하드 드라이브에 재건 행렬을 저장합니다. 주 : 발산 및 ​​평면파 방법은 두 가지 재구성 매트릭스를 사용한다. <ol><li> GPU 행렬에 재건 행렬을 캐스팅합니다. matlab에 명령 창하고 Enter 키를 누르십시오 &quot;입력&quot;제조업체가 위상 배열과 관련된 제공된 스크립트를 사용하여 초음파 채널 데이터 수집을위한 설치 파일을 만들 수있는 평면 파 이미징 웨이브 영상 또는 &quot;SetUpP4_2Flash_4B_streaming_PW&quot;를 발산은 &quot;SetUpP4_2Flash_4B_streaming_DW&quot;를 입력 초음파 시스템. 평면파 이미징 파 이미징 및 &quot;P4-2Flash_PlaneWave.mat&quot;를 발산의 설치 파일 &quot;P4-2Flash_DivergingWave.mat을&quot;이름을 지정합니다. 주 : 상용 소프트웨어 패키지 t 컴퓨터에 설치해야O GPU 행렬에 재건 스파 스 매트릭스를 캐스팅. </li></ol></li><li> 간 높은 프레임 레이트 초음파 데이터 취득 HIFU과 동시에 시작하도록 외부 트리거를 이용하여 함수 발생기와 초음파 시스템을 동기화. </li><li> matlab에를 엽니 다. B 모드 영상을 사용하는 초음파 시스템 제조자에 의해 제공된 설정 스크립트 &quot;SetUpP4_2Flash_4B.m&quot;를 실행. &quot;P4-2Flash_4B_Bmode.mat&quot;생성 된 설치 파일의 이름을 지정합니다. &quot;프로세스에 .MAT 파일의 이름이&quot; &quot;VSX&quot;명령 때 사용하라는 메시지가 표시되어, 설치 파일 &quot;P4-2Flash_4B_Bmode.mat&quot;의 이름을 입력합니다. 모두 트랜스 듀서를 이동하고 브레이션 간 대상 지역에서 그 위치를 컴퓨터 화면 상에 나타난 B-모드 디스플레이를 사용합니다. 흡수로 인해 높은 초음파 감쇠를 피하기 위해 영역을 간 표면 아래 약 1cm 타겟팅. 컴퓨터 간의 종래의 B 모드 영상을 저장한다. 노트 :여기에서 우리는 각 절제에 대한 3 차원 포지셔너와 트랜스 듀서를 이동하여 두 개의 간 시편 11 다른 위치에서 HIFU의 절제를 시행 하였다. </li></ol> 2. 초음파 데이터 수집 <ol><li> matlab에를 엽니 다. &quot;VSX&quot;명령을 사용하여 &quot;프로세스에 .MAT 파일 이름 :&quot;때 메시지가 표시되고, 비행기 파도 웨이브 영상 또는 &quot;P4-2Flash_PlaneWave.mat&quot;를 발산하기위한 설정 파일 &quot;P4-2Flash_DivergingWave.mat&quot;의 이름을 입력합니다 영상. HIFU를 시작하고 대상 지역에 2 분 동안 적용합니다. </li><li> 발산 파를 이용하여 2 분 동안 초당 1,000 프레임에서 RF 채널의 데이터를 획득. 대안 적으로, 2 분 사용 평면파 동안 초당 1,000 프레임에서 RF 채널의 데이터를 획득. </li><li> PCI 익스프레스 케이블을 통해 호스트 컴퓨터 (200)의 모든 프레임 데이터를 전송. 대안 적으로, 실시간 스트리밍, 평면파를 사용하고 TRANSF 2 분 동안 초당 167 프레임에서 RF 채널 데이터를 취득호스트 컴퓨터에 데이터를 매 2 프레임 ER. 참고 : 200 프레임의 세트와 함께 이미징 방법은 각 세트 사이의 각 세트 만 만들 간격 내에서 높은 시간 해상도를 제공하고, 오프라인 처리에 적합하다. FPS (167)에서의 촬상 방법은 낮은 시간 해상도를 가지고 있지만, 전체 박리 시간에 걸쳐 임의의 갭을 ​​생성하지 않고, 실시간 스트리밍에 적합하다. </li><li> matlab에 단일 정밀 GPU 행렬로 RF 채널 행렬 데이터 캐스트. 재구성 된 RF 데이터 (11)를 얻기 위해 재구성 매트릭스에 의해 RF 채널 데이터 행렬을 곱한다. </li></ol> 3. 변위 영상 <ol><li> matlab에의 DSP 시스템 도구 상자를 사용하여 4 MHz의 차단 주파수에서 6 번째 차 버터 워스 저역 통과 필터를 만듭니다. 4.5 MHz의 HIFU 성분을 필터링하는 RF 데이터 재구성이 저역 통과 필터를 적용한다. </li><li> 1-D 정규화 상호 상관을 이용하여 연속적인 프레임 사이의 축 방향 변위를 추정3.1mm-윈도우 길이 및 90 % 겹침. </li><li> matlab에의 DSP 시스템 도구 상자를 사용하여 100 Hz의 차단 주파수에서 6 번째 차 버터 워스 저역 통과 필터를 만듭니다. 50 HZ-진동 주파수 성분을 검색하는 데 사용 매트랩 시간적 변위 데이타에이 저역 통과 필터를 적용한다. </li><li> -6 dB에서 초점 영역으로서 ROI를 정의 (1.7 X 0.4 mm 물) 및 70mm 떨어진 변환기 표면으로부터 위치. 이 투자 수익 (ROI)의 변위 데이터의 압축을 풉니 다. 평균 변위와 ROI의 변위의 표준 편차의 비로서 절제의 2 분 후에 국소 영역에서의 변위 신호 대 잡음비 (SNR의 D)를 추정한다. </li><li> 변위 행렬 데이터의 초점에서 50 Hz의 시간 변위 신호의 압축을 풉니 다. matlab에를 사용하여 가청 사운드에 초점에 시간 변위 신호를 변환합니다. </li></ol>

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The authors declare that they have no competing financial interests.

HIFU 병변의 실시간 모니터링은 적절하고 효율적인 병변 전달을 보장하는 것이 중요하다. 병변의 형태로서, 조직은 경직 및 여기 하의 움직임 진폭은 감소한다. 조직의 변위를 유도하는 음향 방 사력에 티슈 결과 영역 HIFU 적용. 변위의 상대적인 변화는 조직 강성 상대적으로 변화의 대리입니다. 이 기술은 다른 방법에 기초하여 초음파 대조 처리를 중지하지 않고 HIFU 병변을 모니터링하는 장점을 ?...

High Intensity Focused Ultrasound (HIFU) is a technique that generates temperature elevation at the focal region and can be used to ablate cancerous tissue 1. Temperature elevation at the focus causes thermal lesions in the tissue 2. In order to avoid overtreating a region and to reduce treatment duration, it is imperative to reliably monitor the ablation. Magnetic resonance-guided focused ultrasound (MRgFUS) is the main technique used in clinic to guide and monitor HIFU treatment 3. MRI provides high spatial resolution images of the treated region with tissue displacement or thermal dose but has a frame rate of 0.1-1 Hz and is costly. Several ultrasound-based techniques such as B-mode imaging 4, passive acoustic mapping 5, shear wave imaging 6 and acoustic radiation force impulse 7 have been developed to guide and monitor thermal ablation. However, B-mode imaging and passive acoustic mapping do not provide imaging of mechanical properties of the ablated region which is useful to the operator to improve lesion delivery. 
Shear wave imaging and acoustic radiation force impulse can both characterize the elasticity of the tissue by measuring acoustic radiation force-induced displacements 7,8. However, in both methods, the HIFU treatment is typically interrupted to monitor the ablation. Our group has developed a technique called Harmonic Motion Imaging for Focus Ultrasound (HMIFU) which can monitor the HIFU treatment with ultrasound without stopping the ablation9,10. Briefly, a HIFU transducer sends an amplitude-modulated wave to the region to ablate while simultaneously generating an oscillatory motion in the focal region. A co-axially aligned ultrasound transducer is used to image this oscillation. The magnitude of the induced motion is related to the stiffness of the tissue.
To ensure proper lesion delivery, the temporal resolution of real-time monitoring is of key interest in ablation guidance. Recently, our group has shown real-time streaming of displacement at a frame rate up to 15 Hz, imaged with diverging waves in a narrow field of view and using a fast image reconstruction method 11. Several beamforming techniques can be used to image the displacements. A large field of view can be obtained with diverging wave imaging by changing the delay profile but the axial direction is not aligned with the HIFU beam on the lateral regions and the wave is attenuated due to geometric spreading in the lateral direction, which can affect the quality of the displacement estimation. In contrast, the lateral field of view for plane wave is upper bounded by the active aperture but the axial direction is aligned with the HIFU beam at the focus and there is no geometric spreading in the lateral direction. Depending on the type of application, one or the other imaging method can be selected. The objectives of this protocol are to show how plane wave imaging can provide real-time streaming of displacements images using HMIFU during ablation and to compare the quality of the motion estimation between diverging and plane wave imaging.

<table border="0" cellpadding="0" cellspacing="0">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr>
			<td>P4-2 Phased array</td>
			<td>ATL</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>H-178 HIFU transducer</td>
			<td>Sonic Concepts</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>3-D positioner</td>
			<td>Velmex Inc.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>AT33522A function generator</td>
			<td>Agilent Technologies</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>V-1 ultrasound system</td>
			<td>Verasonics</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>3100L RF amplifier</td>
			<td>ENI</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Matching network</td>
			<td>Sonic Concepts</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Degasing system</td>
			<td>Sonic Concepts</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Programming software</td>
			<td>Matlab</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Jacket software package</td>
			<td>Accelereyes</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

real-time monitoring of high intensity focused ultrasound (hifu) ablation of in vitro canine livers using harmonic motion imaging for focused ultrasound (hmifu)

집중 초음파에 대한 조화 운동 이미징 (HMIFU)을 수행하고 높은 강도 (HIFU) 절제 초음파를 집중 모니터링 할 수있는 기술이다. 진동 운동은 함수 발생기를 사용하여 25 Hz의 진폭 변조 신호를인가하여 소자 (93) 및 4.5 MHz의 중심 주파수 HIFU 변환기의 포커스에서 생성된다. 68kPa 피크 압력 64 요소 및 2.5 MHz의 촬상 센서는 공 초점으로 무선 주파수 (RF) 채널 데이터를 취득하는 HIFU 변환기의 중앙에 배치된다. 이 프로토콜에서, 시험 관내 개과 간 7 W의 음향 파워 HIFU를 사용하여 열 삭마의 실시간 모니터링을 설명한다. HIFU 치료는 2 분 동안 조직에 도포되며, 절제 영역은 1000 프레임 / 초로 발산 또는 평면파 이미징을 사용하여 실시간으로 이미징된다. RF 채널 데이터의 매트릭스는 화상 재구성에 대한 희소 행렬에 의해 승산된다. 보기의 재구성 필드는 워싱턴을 발산 90 °이다적이 및 평면파 이미징 20mm 및 데이터는 80 MHz에서 샘플링된다. 재구성 4.5 디스플레이 프레임 레이트로 실시간으로 화상하기 위해 그래픽 처리 장치 (GPU)에 대해 수행된다. 재구성 된 RF 데이터의 1-D 정규화 상호 상관이 초점 영역에서의 축 변위를 추정하는 데 사용된다. 초점 심도의 피크 - 투 - 피크 변위 크기 때문에 병변의 형성 티슈의 강성을 나타낸다 열 절제 동안 감소한다. 평면파의 초점 영역의 변위 신호 대 잡음비 (SNR의 D) 그 평면파 촬상를 나타내는 전파를 발산에 비해 1.4 배 높았다 더 변위 웨이브 촬상 발산보다 HMIFU 품질 맵핑 생성하도록 나타난다.

HIFU 어블 동안 HMI 변위 실시간 스트리밍이 발산 및 평면파 이미징을 사용하여 얻을 수있다. (2)도 것은 HIFU 어블 동안 시험관 개과 간에서 평면파 이미징을 사용하여 음향 방 사력 유도 변위의 실시간 표시를 나타내는 영상 화면 캡처이고 . 변위 4.5 Hz의 디스플레이 프레임 레이트로 컴퓨터 화면에 실시간으로 스트리밍된다. 긍정적 인 변위가 파란색에서 붉은 색과 음의 변위로 ?...

Watch this Scientific Journal Video about Real-time Monitoring of High Intensity Focused Ultrasound HIFU Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound HMIFU a

Real-time Monitoring of High Intensity Focused Ultrasound HIFU Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound HMIFU

This article describes real-time monitoring of HIFU ablation in canine liver with high frame rate ultrasound imaging using diverging and plane wave imaging. Harmonic Motion Imaging for Focused Ultrasound is used to image the decrease of acoustic radiation force induced displacement in the ablated region.

높은 강도의 실시간 모니터링의 초음파 (HIFU) 절제를 집중<em&gt; 체외</em&gt; 집중 초음파에 대한 조화 운동 이미징을 사용하여 개 간을 (HMIFU)

Harmonic Motion Imaging for Focused Ultrasound (HMIFU) is a technique that can perform and monitor high-intensity focused ultrasound (HIFU) ablation. An ...

real-time-monitoring-high-intensity-focused-ultrasound-hifu-ablation

Research

JoVE Journal

Bioengineering

Real-time Monitoring of High Intensity Focused Ultrasound (HIFU) Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound (HMIFU)

9.9K 조회수.  Columbia University. This article describes real-time monitoring of HIFU ablation in canine liver with high frame rate ultrasound imaging using diverging and plane wave imaging. Harmonic Motion Imaging for Focused Ultrasound is used to image the decrease of acoustic radiation force induced displacement in the ablated region.

비디오: Real-time Monitoring of High Intensity Focused Ultrasound HIFU Ablation of In Vitro Canine Livers Using Harmonic Motion Imaging for Focused Ultrasound HMIFU

Contrast Ultrasound Targeted Treatment of Gliomas in Mice via Drug-Bearing Nanoparticle Delivery and Microvascular Ablation

We are developing minimally-invasive contrast agent microbubble based therapeutic approaches in which the permeabilization and/or ablation of the microvasculature are controlled by varying ultrasound pulsing parameters.  Specifically, we are testing whether such approaches may be used to treat malignant brain tumors through drug delivery and microvascular ablation.  Preliminary studies have been performed to determine whether targeted drug-bearing nanoparticle delivery can be facilitated by the ultrasound mediated destruction of "composite" delivery agents comprised of 100nm poly(lactide-co-glycolide) (PLAGA) nanoparticles that are adhered to albumin shelled microbubbles. We denote these agents as microbubble-nanoparticle composite agents (MNCAs). When targeted to subcutaneous C6 gliomas with ultrasound, we observed an immediate 4.6-fold increase in nanoparticle delivery in MNCA treated tumors over tumors treated with microbubbles co-administered with nanoparticles and a 8.5 fold increase over non-treated tumors. Furthermore, in many cancer applications, we believe it may be desirable to perform targeted drug delivery in conjunction with ablation of the tumor microcirculation, which will lead to tumor hypoxia and apoptosis. To this end, we have tested the efficacy of non-theramal cavitation-induced microvascular ablation, showing that this approach elicits tumor perfusion reduction, apoptosis, significant growth inhibition, and necrosis. Taken together, these results indicate that our ultrasound-targeted approach has the potential to increase therapeutic efficiency by creating tumor necrosis through microvascular ablation and/or simultaneously enhancing the drug payload in gliomas.

Insonation of microbubbles is a promising strategy for tumor ablation at reduced time-averaged acoustic powers, as well as for the targeted delivery of therapeutics. The purpose of the present study is to develop low duty cycle ultrasound pulsing strategies and nanocarriers to maximize non-thermal microvascular ablation and payload delivery to subcutaneous C6 gliomas.

명암 초음파 마약 베어링 Nanoparticle 배달 및 Microvascular 절제를 통해 마우스에서 Gliomas의 치료 타겟

We are developing minimally-invasive contrast agent microbubble based therapeutic approaches in which the permeabilization and/or ablation of the ...

연구

생체공학

Decellularization and Recellularization of Whole Livers

The liver is a complex organ which requires constant perfusion for delivery of nutrients and oxygen and removal of waste in order to survive1. Efforts to recreate or mimic the liver microstructure with grounds up approach using tissue engineering and microfabrication techniques have not been successful so far due to this design challenge. In addition, synthetic biomaterials used to create scaffolds for liver tissue engineering applications have been limited in inducing tissue regeneration and repair in large part due to the lack of specific cell binding motifs that would induce the proper cell functions2. Decellularized native tissues such blood vessels3and skin4on the other hand have found many applications in tissue engineering, and have provided a practical solution to some of the challenges. The advantage of decellularized native matrix is that it retains, to an extent, the original composition, and the microstructure, hence enhancing cell attachment and reorganization5.
In this work we describe the methods to perform perfusion-decellularization of the liver, such that an intact liver bioscaffold that retains the structure of major blood vessels is obtained. Further, we describe methods to recellularize these bioscaffolds with adult primary hepatocytes, creating a liver graft that is functional in vitro, and has the vessel access necessary for transplantation in vivo.

Perfusion decellularization is a novel technique to produce whole liver scaffolds that retains the organ's extracellular matrix composition and microarchitecture. Herein, the method of preparing whole organ scaffolds using perfusion decellularization and subsequent repopulation with hepatocytes is described. Functional and transplantable liver grafts can be generated using this technique.

전체 간은의 Decellularization 및 Recellularization

The liver is a complex organ which requires constant perfusion for delivery of nutrients and oxygen and removal of waste in order to survive1. Efforts to ...

Induction of Adhesion-dependent Signals Using Low-intensity Ultrasound

In multicellular organisms, cell behavior is dictated by interactions with the extracellular matrix. Consequences of matrix-engagement range from regulation of cell migration and proliferation, to secretion and even differentiation. The signals underlying each of these complex processes arise from the molecular interactions of extracellular matrix receptors on the surface of the cell. Integrins are the prototypic receptors and provide a mechanical link between extracellular matrix and the cytoskeleton, as well as initiating some of the adhesion-dependent signaling cascades. However, it is becoming increasingly apparent that additional transmembrane receptors function alongside the integrins to regulate both the integrin itself and signals downstream. The most elegant of these examples is the transmembrane proteoglycan, syndecan-4, which cooperates with &alpha;5&beta;1-integrin during adhesion to fibronectin. In vivo models demonstrate the importance of syndecan-4 signaling, as syndecan-4-knockout mice exhibit healing retardation due to inefficient fibroblast migration1,2. In wild-type animals, migration of fibroblasts toward a wound is triggered by the appearance of fibronectin that leaks from damaged capillaries and is deposited by macrophages in injured tissue. Therefore there is great interest in discovering strategies that enhance fibronectin-dependent signaling and could accelerate repair processes.
The integrin-mediated and syndecan-4-mediated components of fibronectin-dependent signaling can be separated by stimulating cells with recombinant fibronectin fragments. Although integrin engagement is essential for cell adhesion, certain fibronectin-dependent signals are regulated by syndecan-4. Syndecan-4 activates the Rac1 protrusive signal3, causes integrin redistribution1, triggers recruitment of cytoskeletal molecules, such as vinculin, to focal adhesions4, and thereby induces directional migration3. We have looked for alternative strategies for activating such signals and found that low-intensity pulsed ultrasound (LIPUS) can mimic the effects of syndecan-4 engagement5. In this protocol we describe the method by which 30 mW/cm2, 1.5 MHz ultrasound, pulsed at 1 kHz (Fig. 1) can be applied to fibroblasts in culture (Fig. 2) to induce Rac1 activation and focal adhesion formation. Ultrasound stimulation is applied for a maximum of 20 minutes, as this combination of parameters has been found to be most efficacious for acceleration of clinical fracture repair6. The method uses recombinant fibronectin fragments to engage &alpha;5&beta;1-integrin, without engagement of syndecan-4, and requires inhibition of protein synthesis by cycloheximide to block deposition of additional matrix by the fibroblasts., The positive effect of ultrasound on repair mechanisms is well documented7,8, and by understanding the molecular effect of ultrasound in culture we should be able to refine the therapeutic technique to improve clinical outcomes.

This protocol describes the stimulation of cultured fibroblasts with low-intensity pulsed ultrasound, which drives focal adhesion formation and Rac1 activation by mimicking engagement of the transmembrane matrix receptor, syndecan-4. This approach allows investigation of a successful clinical technique at the cellular level, thereby providing opportunities for refinement of the therapy.

낮은 강도의 초음파를 사용하여 접착 종속 신호의 유도

In multicellular organisms, cell behavior is dictated by interactions with the extracellular matrix. Consequences of matrix-engagement range from ...

Wideband Optical Detector of Ultrasound for Medical Imaging Applications

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic imaging. In medical applications, one of the major limitations of optical sensing technology is its susceptibility to environmental conditions, e.g. changes in pressure and temperature, which may saturate the detection. Additionally, the clinical environment often imposes stringent limits on the size and robustness of the sensor. In this work, the combination of pulse interferometry and fiber-based optical sensing is demonstrated for ultrasound detection. Pulse interferometry enables robust performance of the readout system in the presence of rapid variations in the environmental conditions, whereas the use of all-fiber technology leads to a mechanically flexible sensing element compatible with highly demanding medical applications such as intravascular imaging. In order to achieve a short sensor length, a pi-phase-shifted fiber Bragg grating is used, which acts as a resonator trapping light over an effective length of 350 &#181;m. To enable high bandwidth, the sensor is used for sideway detection of ultrasound, which is highly beneficial in circumferential imaging geometries such as intravascular imaging. An optoacoustic imaging setup is used to determine the response of the sensor for acoustic point sources at different positions.

Optical detection of ultrasound is impractical in many imaging scenarios because it often requires stable environmental conditions. We demonstrate an optical technique for ultrasound sensing in volatile environments with miniaturization and sensitivity levels appropriate for optoacoustic imaging in restrictive scenarios, e.g. intravascular applications.

광대역 의료 이미징 애플리케이션을위한 초음파의 광 검출기

Optical sensors of ultrasound are a promising alternative to piezoelectric techniques, as has been recently demonstrated in the field of optoacoustic ...

Universal Hand-held Three-dimensional Optoacoustic Imaging Probe for Deep Tissue Human Angiography and Functional Preclinical Studies in Real Time

The exclusive combination of high optical contrast and excellent spatial resolution makes optoacoustics (photoacoustics) ideal for simultaneously attaining anatomical, functional and molecular contrast in deep optically opaque tissues. While enormous potential has been recently demonstrated in the application of optoacoustics for small animal research, vast efforts have also been undertaken in translating this imaging technology into clinical practice. We present here a newly developed optoacoustic tomography approach capable of delivering high resolution and spectrally enriched volumetric images of tissue morphology and function in real time. A detailed description of the experimental protocol for operating with the imaging system in both hand-held and stationary modes is provided and showcased for different potential scenarios involving functional and molecular studies in murine models and humans. The possibility for real time visualization in three dimensions along with the versatile handheld design of the imaging probe make the newly developed approach unique among the pantheon of imaging modalities used in today&#8217;s preclinical research and clinical practice.

We provide herein a detailed description of the experimental protocol for imaging with a newly developed hand-held optoacoustic (photoacoustic) system for three-dimensional functional and molecular imaging in real time. The demonstrated powerful performance and versatility may define new application areas of the optoacoustic technology in preclinical research and clinical practice.

범용 실시간으로 깊은 조직 인간의 혈관 조영술과 기능 전임상 연구를위한 3 차원 광 음향 이미징 프로브를 손 개최

The exclusive combination of high optical contrast and excellent spatial resolution makes optoacoustics (photoacoustics) ideal for simultaneously ...

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 ...

Real Time Monitoring of Intracellular Bile Acid Dynamics Using a Genetically Encoded FRET-based Bile Acid Sensor

F&#246;rster Resonance Energy Transfer (FRET) has become a powerful tool for monitoring protein folding, interaction and localization in single cells. Biosensors relying on the principle of FRET have enabled real-time visualization of subcellular signaling events in live cells with high temporal and spatial resolution. Here, we describe the application of a genetically encoded Bile Acid Sensor (BAS) that consists of two fluorophores fused to the farnesoid X receptor ligand binding domain (FXR-LBD), thereby forming a bile acid sensor that can be activated by a large number of bile acids species and other (synthetic) FXR ligands. This sensor can be targeted to different cellular compartments including the nucleus (NucleoBAS) and cytosol (CytoBAS) to measure bile acid concentrations locally. It allows rapid and simple quantitation of cellular bile acid influx, efflux and subcellular distribution of endogenous bile acids without the need for labeling with fluorescent tags or radionuclei. Furthermore, the BAS FRET sensors can be useful for monitoring FXR ligand binding. Finally, we show that this FRET biosensor can be combined with imaging of other spectrally distinct fluorophores. This allows for combined analysis of intracellular bile acid dynamics and i) localization and/or abundance of proteins of interest, or ii) intracellular signaling in a single cell.

We provide a detailed protocol to study bile acid dynamics in living cells using a genetically encoded BAS FRET sensor. This Bile Acid Sensor represents a unique tool to study (regulation of) bile acid transport and FXR activation in a wide range of cell types.

유전자 인코딩 FRET 기반 담즙 산성 센서를 사용하여 세포 내 담즙 산성 역학의 실시간 모니터링

F&#246;rster Resonance Energy Transfer (FRET) has become a powerful tool for monitoring protein folding, interaction and localization in single cells. ...

Proper Positioning and Restraint of a Rat Hind Limb for Focused High Resolution Imaging of Bone Micro-architecture Using In Vivo Micro-computed Tomography

The use of in vivo micro-computed tomography (&#181;CT) is a powerful tool which involves the non-destructive imaging of internal structures at high resolutions in live animal models. This allows for repeated imaging of the same rodent over time. This feature not only reduces the total number of rodents required in an experimental design and thereby reduces the inter-subject variation that can arise, but also allows researchers to assess longitudinal or life-long responses to an intervention. To acquire high quality images that can be processed and analyzed to more accurately quantify outcomes of bone micro-architecture, users of in vivo &#181;CT scanners must properly anesthetize the rat, and position and restrain the hind limb. To do this, it is imperative that the rat be anesthetized to a level of complete relaxation, and that pedal reflexes are lost. These guidelines may be modified for each individual rat, as the rate of isoflurane metabolism can vary depending on strain and body size. Proper technique for in vivo &#181;CT image acquisition enables accurate and consistent measurement of bone micro-architecture within and across studies.

Proper Positioning and Restraint of a Rat Hind Limb for Focused High Resolution Imaging of Bone Micro-architecture Using In Vivo Micro-computed Tomography

This paper instructs users of in vivo micro-computed tomography (&#181;CT) scanners how to anesthetize, correctly position and restrain the hind limb of a rat for minimal movement during high-resolution imaging of the tibia. The result is high quality images that can be processed to accurately quantify bone micro-architecture.

적절 한 위치와 뼈 마이크로 아키텍처를 사용 하 여 생체 내에서 마이크로-단층의 집중된 고해상도 이미징 쥐 뒷 다리의 구속

The use of in vivo micro-computed tomography (&#181;CT) is a powerful tool which involves the non-destructive imaging of internal structures at high ...

Hand-held Clinical Photoacoustic Imaging System for Real-time Non-invasive Small Animal Imaging

Translation of photoacoustic imaging into the clinic is a major challenge. Handheld real-time clinical photoacoustic imaging systems are very rare. Here, we report a combined photoacoustic and clinical ultrasound imaging system by integrating an ultrasound probe with light delivery for small animal imaging. We demonstrate this by showing sentinel lymph node imaging in small animals along with minimally invasive real-time needle guidance. A clinical ultrasound platform with access to raw channel data allows the integration of photoacoustic imaging leading to a handheld real-time clinical photoacoustic imaging system. Methylene blue was used for sentinel lymph node imaging at 675 nm wavelength. Additionally, needle guidance with dual modal ultrasound and photoacoustic imaging was shown using the imaging system. Depth imaging of up to 1.5 cm was demonstrated with a 10 Hz laser at a photoacoustic imaging frame rate of 5 frames per second.

A clinical handheld photoacoustic imaging system will be demonstrated for real-time non-invasive small animal imaging.

휴대용 임상 Photoacoustic 실시간 비-침략 적 작은 동물 이미징을 위한 이미징 시스템

Translation of photoacoustic imaging into the clinic is a major challenge. Handheld real-time clinical photoacoustic imaging systems are very rare. Here, ...

Focused Ion Beam Lithography to Etch Nano-architectures into Microelectrodes

With advances in electronics and fabrication technology, intracortical microelectrodes have undergone substantial improvements enabling the production of sophisticated microelectrodes with greater resolution and expanded capabilities. The progress in fabrication technology has supported the development of biomimetic electrodes, which aim to seamlessly integrate into the brain parenchyma, reduce the neuroinflammatory response observed after electrode insertion and improve the quality and longevity of electrophysiological recordings. Here we describe a protocol to employ a biomimetic approach recently classified as nano-architecture. The use of focused ion beam lithography (FIB) was utilized in this protocol to etch specific nano-architecture features into the surface of non-functional and functional single shank intracortical microelectrodes. Etching nano-architectures into the electrode surface indicated possible improvements of biocompatibility and functionality of the implanted device. One of the benefits of using FIB is the ability to etch on manufactured devices, as opposed to during the fabrication of the device, facilitating boundless possibilities to modify numerous medical devices post-manufacturing. The protocol presented herein can be optimized for various material types, nano-architecture features, and types of devices. Augmenting the surface of implanted medical devices can improve the device performance and integration into the tissue.

We have shown that the etching of nano-architecture into intracortical microelectrode devices may reduce the inflammatory response and has the potential to improve electrophysiological recordings. The methods described herein outline an approach to etch nano-architectures into the surface of non-functional and functional single shank silicon intracortical microelectrodes.

마이크로 전극에 에칭 나노 아키텍처에 초점을 맞춘 이온 빔 리소그래피

With advances in electronics and fabrication technology, intracortical microelectrodes have undergone substantial improvements enabling the production of ...