Financiamento: Exército dos EUA Medical Research &amp; Comando de Material (USAMRMC) e gerido pela Telemedicina e Tecnologia Avançada Research Center. Shunxi Ji contribuiu a modificação das seringas, conforme descrito aqui.

1. System Set-up O sistema consiste de um tanque de retenção e a concentração (HCT), equipado com um misturador único estágio, um homogeneizador de cisalhamento elevado, em linha, uma bomba de rolo para deslocar o fluido entre o HCT e o homogeneizador, e um permutador de calor (Figura 1). <ol><li> Coloque uma esterilizado de boca larga 4 L embarcação, coleta de vidro equipado com 2 portas de base e 3 portas laterais abaixo do único misturador palco. Abaixe a cabeça misturadora para a boca do navio e garantir um encaixe à prova de gás utilizando vedações de borracha ou fita (a fim de evitar que o ar ambiente de contaminar o espaço cabeça). </li><li> Coloque uma das portas de base (Figura 1, a porta # 1) do HCT com estéril 3/8 &quot;(ID) tubulação clara, aproximadamente 10&quot; de comprimento, equipado com uma torneira de 3 vias na ponta para a coleta da emulsão concentrada . </li><li> Coloque a segunda porta de base (Figura 1, a porta # 2) com estéril 3/8 &quot;(ID) tubulação, approximately 36 &quot;de comprimento. Alimente esta tubulação através de uma bomba de roletes. Coloque a entrada do homogeneizador de alto cisalhamento com uma peça em T, incluindo duas portas e ligar da seguinte forma: conectar a tubulação da porta n º 2, por meio da bomba de roletes e conectar à porta lateral do T-peça. Prenda a outra porta para um tanque de oxigênio usando um baixo fluxo de medidor de vazão de gás oxigênio. </li><li> Ligue o orifício de saída do homogeneizador de cisalhamento elevado à porta de entrada de um permutador de calor em linha, mantida a 4 ° C. Ligue o orifício de saída do permutador de calor para o canal de retorno do HCT (Figura 1, a porta # 3), a criação de um sistema de circuito fechado. </li><li> Anexar um tanque de oxigênio (através de um medidor de fluxo) para o HCT (Figura 1, a porta # 4). Anexar um monitor de composição do gás que está aberto para a atmosfera para o topo da porta do HCT (Figura 1, a porta n º 5). </li><li> Se for desejada a esterilidade, esterilizar os componentes de vidro e de metal, antes de cada uso por autoclavagem. Esterilizar os componentes de tubulação e co plásticonnectors por óxido de etileno, antes de cada utilização. Isto é especialmente importante se o produto é para ser testado in vivo. </li></ol> 2. LOM Fabricação <ol><li> Colocar 20 g de 1,2-GMP distearoil-sn-glicero-3-fosfocolina (DSPC) e 10 g de colesterol na base da HCT. Adicionar 1 L de Plasma-Lyte A a o HCT e agitar mão durante 1 min, integrando tanto lipídica como possível para a fase aquosa. </li><li> Diminuir o misturador único estágio para a fase aquosa, assegurando que toda a cabeça do misturador é coberto pela fase aquosa. Certifique-se de que o topo do HCT é o gás apertado (ver passo 1.1 acima), e que não há portas laterais abertas. Ligue a fonte de gás conectado à porta # 4 e esperar até que a fração de oxigênio do headspace HCT atinge&gt; 95%. Aos 10 L / min (LPM), este deve tomar ~ 10 min. </li><li> Utilizando o misturador único estágio, misturar a emulsão precursora durante 5 min a 5000 rpm. A mistura resultante deve aparecer pálida e não contêm lipi visíveld aglomerados. Uma vez misturado, mistura lipídica de água não utilizada pode ser armazenado a 4 º C por até 30 dias antes da utilização única. </li><li> Primeiro o sistema de circuito fechado de todo com a emulsão precursor ligando a bomba de roletes em 1,3 LPM. Uma vez que o sistema está preparado, mantenha a bomba em 1,3 LPM. </li><li> Para começar a fabricação dos LOMs, ligue o homogeneizador de alto cisalhamento em linha de 7.500 rpm. Imediatamente depois, ligar o fluxo de oxigênio para o troço de entrada do homogeneizador de 0,5 LPM. Manter a batedeira fase única (no HCT) sobre a 3.500 rpm. LOM são formadas na interface das lâminas do rotor e as telas Emulsor dentro do homogeneizador em linha (Figura 2). Dentro de minutos, o líquido deve tornar-se visivelmente mais viscoso. Uma abordagem mais rigorosa é a determinação da viscosidade em função do tempo, o que pode ser feito através da remoção de alíquotas a partir de uma porta, durante a fabricação e analisando com um viscosímetro. Nota: Se as bolhas de ar visíveis estão presentes na tubagem de saída do misturador, oxigéniofluir para o homogeneizador em linha é demasiado elevada. Titular baixo fluxo de gás até que o fluido é opaco e não contém bolhas de gás visíveis. </li><li> Execute o sistema por 15 min, em seguida, desligue o homogeneizador de alto cisalhamento ea entrada de oxigênio para ele. Continuar a rodar o misturador único estágio no HCT até a emulsão é removido; isto reduz a separação de fases e mantém o produto relativamente uniforme no interior da HCT. Nota: O volume da emulsão cheia de gás deve aumentar de cerca de 2 a 3 vezes durante a fase de concentração de série. Se isso não ocorrer, verifique se o oxigênio está fluindo para o homogeneizador de alto cisalhamento e que as concentrações de lipídios na emulsão precursor estão corretos. A eficiência de produção diminui à medida que diminui a concentração de lípidos. </li></ol> 3. Cobrança, a concentração, Avaliação e armazenamento de LOMs <ol><li> Anexar uma estéril, modificado 140 ml seringa luer-lock para a torneira ligada a porta base N º 1 na embarcação coleção. Elaborar 100 ml de fluido. Tapar bem seringa e repetir até que todo o fluido foi removido. <ol><li> Modificar seringas retirando 100 ml de ar na seringa e, em seguida, o excesso de serrar o êmbolo e o material da seringa acima da marca de 140 ml. Preencha e seringas vazias, usando uma pinça dentada para elaborar o êmbolo. Esta modificação facilita a centrifugação. </li></ol></li><li> Seringas de centrífuga com a extremidade tampada orientada para baixo num frigorífico (4 ° C) balde centrifugar a 225 xg durante 10 min. </li><li> Três camadas de material aparece após centrifugação. Expulse a camada inferior do excesso de fase aquosa nublado e descarte. A segunda camada é branco brilhante e contém LOMs concentrados. Transferir espuma concentrada para uma seringa impermeável aos gases utilizando uma torneira de três vias para evitar uma contaminação de gás ambiente. Descarte a camada final, que contém gás oxigênio livre de LOMs rompidos. </li><li> A qualidade da espuma pode ser avaliada pela atingindo ≥ 90% de gás de espuma concentrada. CalculComeram a concentração de gás como se segue: Volume de gás% = [(peso da espuma / volume de espuma) - 1] x 100 <ol><li> Como um controlo de qualidade segundo, microbolhas de tamanho por obscurecimento de luz para determinar se o tamanho das partículas está dentro do intervalo esperado. Deve notar-se que uma alteração no tempo de homogeneização ou formulação pode alterar o tamanho da bolha. </li></ol></li><li> Tapar bem a seringa de vidro com um encaixe luer. LOM concentradas podem ser diluídas com Plasma-Lyte A a o tempo de utilização. As seringas podem ser armazenadas a 22, 4, ou -20 º C; temperaturas mais baixas podem proporcionar maior estabilidade vida de prateleira 7. </li></ol>

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Os autores declaram que não têm interesses financeiros concorrentes.

Os passos mais importantes para a criação de concentrados, LOMs altamente oxigenados incluem: 1) assegurar que o espaço livre dentro do HCT permanece totalmente oxigenado; 2) garantia de que a pureza dos excipientes de lipídios é o ideal (incluindo as condições de armazenamento e uso de produtos de BPF); 3) assegurar que os lípidos em pó misturar completamente com a fase aquosa antes de escorvamento do sistema; e 4) prestando atenção para o aumento da fração de gás dentro do HCT para garantir que a fraçã...

As microbolhas compostas de proteína, de polímero, e os reservatórios de lípidos têm sido desenvolvidos como vectores para a entrega da droga, a terapia génica, e os agentes de contraste de ultra-sons 1-5. Porque esses usos terapêuticos exigem persistência microbolhas intravascular, tais microbolhas são comumente cheio de inertes, altos gases peso molecular, tais como perfluorcarbonos 6, que possuem baixa solubilidade no sangue e estabilizar a 3,4 bolha. Recentemente, microbolhas de oxigênio à base de lipídios (LOMs) foram projetados para fornecer as doses terapêuticas de oxigênio, que podem preservar a oferta de oxigênio de órgãos-alvo e evitar instabilidade hemodinâmica durante os períodos de obstrução das vias aéreas ou hipoxemia 7. Emulsões projetados para entrega de gás intravenosa requerem diferentes características de design do que os utilizados para os agentes de contraste de ultra-som ou entrega de drogas específicas. Primeiro, porque o corpo consome grandes volumes de gás de oxigénio (~ 200 ml / min), de LOM deve ser produzido einjectado em larga escala. Isto requer que o processo de fabrico seja eficaz. Em segundo lugar, o processo de fabrico deve ser de circuito fechado, a fim de evitar a contaminação de azoto através da exposição de LOM (que deve ser preenchido com 100% de oxigénio) para o ar ambiente. Em terceiro lugar, porque a finalidade da LOM é a entrega de gás por via intravenosa, a fração de gás de LOMs deve ser maximizado, reconhecendo as limitações impostas pela emulsão viscosidade 7. Finalmente, como com qualquer injectável intravenosa, o controlo preciso sobre a distribuição de tamanho de partícula é essencial para evitar a obstrução microvascular 8. Existem vários métodos estabelecidos para o fabrico de micro-bolhas. A sonicação utiliza alta intensidade, o ultra-som de baixa frequência aplicada para a interface ar-fluido de uma emulsão que compreende um surfactante, tal como um fosfolípido anfipática, na presença de uma câmara de expansão de gás para produzir microbolhas 7,9. Este processo pode ser controlado por variação de ultrafrequência de som, energia e duração do impulso, e a distribuição de tamanho resultante pode ser adaptada para a produção de microbolhas com uma distribuição de tamanho específico, embora sonicação é raramente utilizado no fabrico de microbolhas clinicamente utilizadas. Fusão é a intensa agitação mecânica de um surfactante e gás num sistema fechado, o que também é difícil escalar para acomodar grandes volumes de 2. Microfluídica baseada em gota permite o controle preciso da distribuição de tamanho de microbolhas 10-13. Embora tradicionalmente difícil de escalar, multi-canal, microfluídica de alta velocidade foram descritos o que aumenta a eficiência da produção de microbolhas 13. Microbolhas fabricados usando qualquer um destes métodos pode exigir processos de redução de tamanho de pós-fabricação, tais como fracionamento centrífuga 14,15 e microbolhas flutuação 16,17. Outro método estabelecido para a produção de microbolhas é altamente estáveis ​​homogeniz cisalhamentoção 6, o que pode resultar num padrão hexagonal fosfolípido estabilizador sobre a superfície da microbolha 18. Com base neste conceito, descrevemos a incorporação de um homogeneizador de alto cisalhamento in-line para criar auto-montagem LOMs 19. Neste processo, o homogeneizador utiliza lâminas de rotação rápida, em estreita proximidade com as telas de malha dupla Emulsor finas, criando alto cisalhamento mecânico e hidráulico para a criação de microbolhas. Concentração de série da emulsão lipídica, por meio deste sistema produz uma fracção de gás cada vez mais concentrada, o que pode ser ainda mais concentrado por centrifugação.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr height="42">
			<td height="42" style="height:43px;width:239px;">Name of Material/ Equipment</td>
			<td style="width:141px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:405px;">Comments/Description</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)</td>
			<td style="width:141px;">Avanti Polar Lipids</td>
			<td style="width:119px;">770365</td>
			<td>Alternate product: non-GMP from NOF America (Coatsome MC-8080)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Cholesterol</td>
			<td style="width:141px;">Sigma Aldrich</td>
			<td style="width:119px;">C75209</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Plasma-Lyte A</td>
			<td style="width:141px;">VWR</td>
			<td style="width:119px;">80089-818</td>
			<td>Alternatively can use NaCl</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Glass collection vessel</td>
			<td style="width:141px;">Specialty Glass, Inc.</td>
			<td style="width:119px;">Custom</td>
			<td>Contact: Pam Zurbrick - 281-595-2210</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Gas composition (oxygen) monitor</td>
			<td style="width:141px;">Precision Medical</td>
			<td style="width:119px;">PM5900L</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">Sarns 8000 roller pump</td>
			<td style="width:141px;">Calicut Medical</td>
			<td style="width:119px;">16407</td>
			<td>Part of a modular perfusion system</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">BIOtherm Heat Exchanger</td>
			<td style="width:141px;">Medtronic</td>
			<td style="width:119px;">ECMOtherm-II</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">Verso laboratory in-line mixer</td>
			<td style="width:141px;">Silverson Machines, Inc</td>
			<td style="width:119px;">TH-IL-102-VERSO</td>
			<td>Use multistage workheads and front-end extension with T piece</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">T-piece for Silverson Verso inlet port</td>
			<td style="width:141px;">Process Innovations</td>
			<td style="width:119px;">Custom</td>
			<td>Contact: Brian Leavitt - 508-423-2266</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">L5M-A laboratory mixer</td>
			<td style="width:141px;">Silverson Machines, Inc</td>
			<td style="width:119px;">NC0136483</td>
			<td>Use mesh emulsor screen (fine)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">Rochester-Ochsner toothed forceps</td>
			<td style="width:141px;">Fisher Scientific</td>
			<td style="width:119px;">13-812-18</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">140 mL syringe</td>
			<td style="width:141px;">Kendall Healthcare Monoject&#160;</td>
			<td style="width:119px;">8881114030</td>
			<td>Ensure there is a luer lock.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:239px;">IX71 Inverted light microscope</td>
			<td style="width:141px;">Olympus</td>
			<td style="width:119px;">IX71</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:239px;">Retiga-2000R microscope camera</td>
			<td style="width:141px;">QImaging</td>
			<td style="width:119px;">RET-2000R-F-M-12</td>
			<td></td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:239px;">Accusizer 780A Autodilution</td>
			<td style="width:141px;">PSS-NICOMP Particle Sizing Systems</td>
			<td style="width:119px;">Out of production</td>
			<td></td>
		</tr>
	</tbody>
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manufacture of concentrated, lipid-based oxygen microbubble emulsions by high shear homogenization and serial concentration

Microbolhas cheias de gás têm sido desenvolvidos como agentes de contraste de ultra-sons e de entrega de drogas. As microbolhas pode ser produzido através da transformação de surfactantes usando sonicação, agitação mecânica, dispositivos de microfluidos, ou homogeneização. Recentemente, microbolhas de oxigênio à base de lipídios (LOMs) foram projetados para fornecer oxigênio por via intravenosa durante emergências médicas, revertendo hipoxemia risco de vida, prevenção de lesões e posterior do órgão, parada cardíaca e morte. Nós apresentamos métodos para produção em escala-up de microbolhas altamente oxigenados usando um circuito fechado de alto cisalhamento homogeneizador. O processo pode produzir 2 L de LOM concentradas (90% em volume), em 90 min. Bolhas resultantes têm um diâmetro médio de cerca de 2 um, e um perfil reológico consistente com o do sangue, quando diluído para 60% em volume. Esta técnica produz LOM em alta capacidade e com uma pureza elevada de oxigénio, o que sugere que esta técnica pode ser útil para laboratórios de pesquisa translacional.

Homogeneização de alto cisalhamento permite a produção eficiente (ou seja, dentro de uma tarde) de LOMs suficientes para um estudo animal e não requer conhecimento técnico. Uma vez proficiente, até 2 L de LOM concentradas podem ser fabricados em 90 min. Tamanhos de microbolhas e morfologia foi analisada por microscopia de luz e pelo obscurecimento. Quando uma amostra de 10 ul da LOM foi visualizado, LOM esféricas, foram observadas, bem como uma relativa escassez de detritos ...

Watch this Scientific Journal Video about Manufacture of Concentrated, Lipid-based Oxygen Microbubble Emulsions by High Shear Homogenization and Serial Concentration at JoVE.com

Manufacture of Concentrated, Lipid-based Oxygen Microbubble Emulsions by High Shear Homogenization and Serial Concentration

Nós descrevem métodos para o fabrico de grandes volumes de microbolhas de oxigénio à base de lípidos (LOMs) concebidas para o fornecimento de oxigénio intravenosa usando homogeneização de alto cisalhamento e de concentração em série.

Fabricação de concentrado, oxigênio à base de microbolhas Lipid Emulsões pelo Alto cisalhamento homogeneização e Concentração de série

Gas-filled microbubbles have been developed as ultrasound contrast and drug delivery agents. Microbubbles can be produced by processing surfactants using ...

manufacture-concentrated-lipid-based-oxygen-microbubble-emulsions

Research

JoVE Journal

Bioengineering

14.9K visualizações.  Harvard Medical School.  Nós descrevem métodos para o fabrico de grandes volumes de microbolhas de oxigénio à base de lípidos (LOMs) concebidas para o fornecimento de oxigénio intravenosa usando homogeneização de alto cisalhamento e de concentração em série. 

Vídeo: Manufacture of Concentrated, Lipid-based Oxygen Microbubble Emulsions by High Shear Homogenization and Serial Concentration

Introduction to the Ultrasound Targeted Microbubble Destruction Technique

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents7-9. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region10. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

Ultrasound Targeted Microbubble Destruction (UTMD) can be used to direct site-specific delivery of bioactive molecules, including therapeutic genes, to target organs accessible to ultrasound, such as the heart and liver1-6.

Introdução à Técnica Destruição Ultrasound Targeted microbolhas

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid ...

Bioengenharia

Characteristics of Precipitation-formed Polyethylene Glycol Microgels Are Controlled by Molecular Weight of Reactants

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer several advantages over traditional microsphere fabrication techniques. Contrary to emulsion, suspension, and dispersion techniques, microgels formed by precipitation are of uniform shape and size, i.e.&#160;low polydispersity index, without the use of organic solvents or stabilizers. The mild conditions of the precipitation reaction, customizable properties of the microgels, and low viscosity for injections make them applicable for in vivo purposes. Unlike other fabrication techniques, microgel characteristics can be modified by changing the starting polymer molecular weight. Increasing the starting PEG molecular weight increased microgel diameter and swelling ratio. Further modifications are suggested such as encapsulating molecules during microgel crosslinking. Simple adaptations to the PEG microgel building blocks are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds.

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Increasing the PEG molecular weight increased microgel diameter and swelling ratio. Simple adaptations to the PEG microgel precipitation reaction are explored for future applications of microgels as drug delivery vehicles and tissue engineering scaffolds.

This work describes the formation of poly(ethylene glycol) (PEG) microgels via a photopolymerized precipitation reaction. Precipitation reactions offer ...

Generation of Shear Adhesion Map Using SynVivo Synthetic Microvascular Networks

Cell/particle adhesion assays are critical to understanding the biochemical interactions involved in disease pathophysiology and have important applications in the quest for the development of novel therapeutics. Assays using static conditions fail to capture the dependence of adhesion on shear, limiting their correlation with in vivo environment. Parallel plate flow chambers that quantify adhesion under physiological fluid flow need multiple experiments for the generation of a shear adhesion map. In addition, they do not represent the in vivo scale and morphology and require large volumes (~ml) of reagents for experiments. In this study, we demonstrate the generation of shear adhesion map from a single experiment using a microvascular network based microfluidic device, SynVivo-SMN. This device recreates the complex in vivo vasculature including geometric scale, morphological elements, flow features and cellular interactions in an in vitro format, thereby providing a biologically realistic environment for basic and applied research in cellular behavior, drug delivery, and drug discovery. The assay was demonstrated by studying the interaction of the 2 &#181;m biotin-coated particles with avidin-coated surfaces of the microchip. The entire range of shear observed in the microvasculature is obtained in a single assay enabling adhesion vs. shear map for the particles under physiological conditions.

Flow chambers used in adhesion experiments typically consist of linear flow paths and require multiple experiments at different flow rates to generate a shear adhesion map. SynVivo-SMN enables the generation of shear adhesion map using a single experiment utilizing microliter volumes resulting in significant savings in time and consumables.

Geração de cisalhamento Adesão Mapa Usando SynVivo Networks microvasculares sintético

Cell/particle adhesion assays are critical to understanding the biochemical interactions involved in disease pathophysiology and have important ...

High-resolution Spatiotemporal Analysis of Receptor Dynamics by Single-molecule Fluorescence Microscopy

Single-molecule microscopy is emerging as a powerful approach to analyze the behavior of signaling molecules, in particular concerning those aspect (e.g., kinetics, coexistence of different states and populations, transient interactions), which are typically hidden in ensemble measurements, such as those obtained with standard biochemical or microscopy methods. Thus, dynamic events, such as receptor-receptor interactions, can be followed in real time in a living cell with high spatiotemporal resolution. This protocol describes a method based on labeling with small and bright organic fluorophores and total internal reflection fluorescence (TIRF) microscopy to directly visualize single receptors on the surface of living cells. This approach allows one to precisely localize receptors, measure the size of receptor complexes, and capture dynamic events such as transient receptor-receptor interactions. The protocol provides a detailed description of how to perform a single-molecule experiment, including sample preparation, image acquisition and image analysis. As an example, the application of this method to analyze two G-protein-coupled receptors, i.e., &#946;2-adrenergic and &#947;-aminobutyric acid type B (GABAB) receptor, is reported. The protocol can be adapted to other membrane proteins and different cell models, transfection methods and labeling strategies.

This protocol describes how to use total internal reflection fluorescence microscopy to visualize and track single receptors on the surface of living cells and thereby analyze receptor lateral mobility, size of receptor complexes as well as to visualize transient receptor-receptor interactions. This protocol can be extended to other membrane proteins.

De alta resolução espacial e temporal Análise de Receptor Dynamics por uma única molécula de microscopia de fluorescência

Single-molecule microscopy is emerging as a powerful approach to analyze the behavior of signaling molecules, in particular concerning those aspect (e.g., ...

Synthesis of Gold Nanoparticle Integrated Photo-responsive Liposomes and Measurement of Their Microbubble Cavitation upon Pulse Laser Excitation

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the development process and are unprocurable by clinics. Here, we describe a facile fabrication of these photo-responsive NPs with commercially available gold NPs and thermo-responsive liposomes. Calcein is used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Finally, we show that this photo-triggered release is due to the membrane disruption caused by microbubble cavitation, which can be measured with hydrophone.

This protocol describes a simple preparation method for gold nanoparticle integrated photo-responsive liposomes with the commercially available materials. It also shows how to measure the microbubble cavitation process of the synthesized liposomes upon the treatment of pulsed laser.

Síntese de nanopartículas de ouro lipossomas Integrated Photo-reactivos e medição das suas microbolhas cavitação em cima do pulso laser de excitação

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control ...

Manufacture and Drug Delivery Applications of Silk Nanoparticles

Silk is a promising biopolymer for biomedical and pharmaceutical applications due to its outstanding mechanical properties, biocompatibility and biodegradability, as well its ability to protect and subsequently release its payload in response to a trigger. While silk can be formulated into various material formats, silk nanoparticles are emerging as promising drug delivery systems. Therefore, this article covers the procedures for reverse engineering silk cocoons to yield a regenerated silk solution that can be used to generate stable silk nanoparticles. These nanoparticles are subsequently characterized, drug loaded and explored as a potential anticancer drug delivery system. Briefly, silk cocoons are reverse engineered first by degumming the cocoons, followed by silk dissolution and clean up, to yield an aqueous silk solution. Next, the regenerated silk solution is subjected to nanoprecipitation to yield silk nanoparticles &#8211; a simple but powerful method that generates uniform nanoparticles. The silk nanoparticles are characterized according to their size, zeta potential, morphology and stability in aqueous media, as well as their ability to entrap a chemotherapeutic payload and kill human breast cancer cells. Overall, the described methodology yields uniform silk nanoparticles that can be readily explored for a myriad of applications, including their use as a potential nanomedicine.

Nanoparticles are emerging as promising drug delivery systems for a broad range of indications. Here, we describe a simple yet powerful method to manufacture silk nanoparticles using reverse engineered Bombyx mori silk. These silk nanoparticles can be readily loaded with a therapeutic payload and subsequently explored for drug delivery applications.

Fabricação e entrega da droga Aplicações de seda Nanopartículas

Silk is a promising biopolymer for biomedical and pharmaceutical applications due to its outstanding mechanical properties, biocompatibility and ...

Quantifying Intermembrane Distances with Serial Image Dilations

A recently-described extracellular nanodomain, termed the perinexus, has been implicated in ephaptic coupling, which is an alternative mechanism for electrical conduction between cardiomyocytes. The current method for quantifying this space by manual segmentation is slow and has low spatial resolution.We developed an algorithm that uses serial image dilations of a binary outline to count the number of pixels between two opposing 2 dimensional edges.This algorithm requires fewer man hours and has a higher spatial resolution than the manual method while preserving the reproducibility of the manual process.In fact, experienced and novice investigators were able to recapitulate the results of a previous study with this new algorithm.The algorithm is limited by the human input needed to manually outline the perinexus and computational power mainly encumbered by a pre-existing pathfinding algorithm.However, the algorithm&#39;s high-throughput capabilities, high spatial resolution and reproducibility make it a versatile and robust measurement tool for use across a variety of applications requiring the measurement of the distance between any 2-dimensional (2D) edges.

The purpose of this algorithm is to continuously measure the distance between two 2-dimensional edges using serial image dilations and pathfinding. This algorithm can be applied to a variety of fields such as cardiac structural biology, vascular biology, and civil engineering.

Quantificar intermembranar distâncias com dilatações imagem Serial

A recently-described extracellular nanodomain, termed the perinexus, has been implicated in ephaptic coupling, which is an alternative mechanism for ...

Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles

Reactive oxygen species (ROS) accumulation is a hallmark of plant abiotic stress response. ROS play&#160;a dual role in plants by acting as signaling molecules at low levels and damaging molecules at high levels. Accumulation of ROS in stressed plants can damage metabolites, enzymes, lipids, and DNA, causing a reduction of plant growth and yield. The ability of cerium oxide nanoparticles (nanoceria) to catalytically scavenge ROS in vivo provides a unique tool to understand and bioengineer plant abiotic stress tolerance. Here, we present a protocol to synthesize and characterize poly (acrylic) acid coated nanoceria (PNC), interface the nanoparticles with plants via leaf lamina infiltration, and monitor their distribution and ROS scavenging in vivo using confocal microscopy. Current molecular tools for manipulating ROS accumulation in plants are limited to model species and require laborious transformation methods. This protocol for in vivo ROS scavenging has the potential to be applied to wild type plants with broad leaves and leaf structure like Arabidopsis thaliana.

Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles

Here, we present a protocol for the synthesis and characterization of cerium oxide nanoparticles (nanoceria) for ROS (reactive oxygen species) scavenging in vivo, nanoceria imaging in plant tissues by confocal microscopy, and in vivo monitoring of nanoceria ROS scavenging by confocal microscopy.

Limpeza catalítica de planta reativas de oxigênio espécies na Vivo por nanopartículas de óxido de cério aniônicos

Reactive oxygen species (ROS) accumulation is a hallmark of plant abiotic stress response. ROS play&#160;a dual role in plants by acting as signaling ...

Detection of Endotoxin in Nano-formulations Using Limulus Amoebocyte Lysate (LAL) Assays

When present in pharmaceutical products, a Gram-negative bacterial cell wall component endotoxin (often also called lipopolysaccharide) can cause inflammation, fever, hypo- or hypertension, and, in extreme cases, can lead to tissue and organ damage that may become fatal. The amounts of endotoxin in pharmaceutical products, therefore, are strictly regulated. Among the methods available for endotoxin detection and quantification, the Limulus Amoebocyte Lysate (LAL) assay is commonly used worldwide. While any pharmaceutical product can interfere with the LAL assay, nano-formulations represent a particular challenge due to their complexity. The purpose of this paper is to provide a practical guide to researchers inexperienced in estimating endotoxins in engineered nanomaterials and nanoparticle-formulated drugs. Herein, practical recommendations for performing three LAL formats including turbidity, chromogenic and gel-clot assays are discussed. These assays can be used to determine endotoxin contamination in nanotechnology-based drug products, vaccines, and adjuvants.

Detection of Endotoxin in Nano-formulations Using Limulus Amoebocyte Lysate LAL Assays

Detection of endotoxins in engineered nanomaterials represents one of the grand challenges in the field of nanomedicine. Here, we present a case study that describes the framework composed of three different LAL formats to estimate potential endotoxin contamination in nanoparticles.

Deteção da endotoxina em Nano-formulações usando Limulus Amoebocyte Lysate (LAL) ensaios

When present in pharmaceutical products, a Gram-negative bacterial cell wall component endotoxin (often also called lipopolysaccharide) can cause ...

Fabrication of Zero Mode Waveguides for High Concentration Single Molecule Microscopy

In single molecule fluorescence enzymology, background fluorescence from labeled substrates in solution often limits fluorophore concentration to pico- to nanomolar ranges, several orders of magnitude less than many physiological ligand concentrations. Optical nanostructures called zero mode waveguides (ZMWs), which are 100&#8722;200 nm in diameter apertures fabricated in a thin conducting metal such as aluminum or gold, allow imaging of individual molecules at micromolar concentrations of fluorophores by confining visible light excitation to zeptoliter effective volumes. However, the need for expensive and specialized nanofabrication equipment has precluded the widespread use of ZMWs. Typically, nanostructures such as ZMWs are obtained by direct writing using electron beam lithography, which is sequential and slow. Here, colloidal, or nanosphere, lithography is used as an alternative strategy to create nanometer-scale masks for waveguide fabrication. This report describes the approach in detail, with practical considerations for each phase. The method allows thousands of aluminum or gold ZMWs to be made in parallel, with final waveguide diameters and depths of 100&#8722;200 nm. Only common lab equipment and a thermal evaporator for metal deposition are required. By making ZMWs more accessible to the biochemical community, this method can facilitate the study of molecular processes at cellular concentrations and rates.

Described here is a nanosphere lithography method for parallel fabrication of zero mode waveguides, which are arrays of nanoapertures in a metal-clad glass microscopy coverslip for single molecule imaging at nano- to micromolar concentrations of fluorophores. The method takes advantage of colloidal crystal self-assembly to create a waveguide template.

Fabricação de guias de ondas de modo zero para microscopia de molécula única de alta concentração

In single molecule fluorescence enzymology, background fluorescence from labeled substrates in solution often limits fluorophore concentration to pico- to ...