Name: mouse microsurgery infusion technique for targeted substance delivery into the cns via the internal carotid artery
Uploaded: 2017-01-31T14:00:00.000+00:00
Duration: 6 min 41 s
Description: Watch this Scientific Journal Video about Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery at JoVE.com

We would like to thank Dr. Lei Chen (Icahn School of Medicine at Mount Sinai, NY) who first established the use of this model in our laboratory, and to Dr. Gretchen Wolff (German Cancer Research Center, Heidelberg, Germany) for disseminating the technique in our laboratory. Supported in part by HL126559, DA039576, MH098891, MH63022, MH072567, DA027569, and NSC 2015/17/B/NZ7/02985.

Os procedimentos envolvidos no protocolo seguinte foram aprovados pela Universidade de Miami Animal Care Institucional e Comitê de Uso (IACUC). Além disso, todos os procedimentos estão sendo realizados em instalações aprovadas pela Associação de Avaliação e Acreditação do Laboratório de Animal Care International (AAALAC). 1. Preparação de Ratos para Cirurgia <ol><li> Anestesiar rato com isoflurano misturado com o oxigênio, usando um sistema de anestesia laboratório. Use isoflurano na definição entre 4-5% e fluxo de oxigênio a 2 L / min na máquina comercial (Veja a Tabela de Materiais). Transferir o animal para a superfície da cirurgia, sob um microscópio estereoscópico, e manter a anestesia utilizando um cone de nariz (1.5 usar uma configuração de isoflurano - 2,5 e de oxigénio no fluxo de 2 L / min). <ol><li> Certifique-se de que a taxa respiratória do rato é de cerca de 1-2 respiração / seg sem ofegante. Além disso, garantir que o animal não apresenta reação estimulação bigodes e pedal reFlex (toe pitada). Monitorar a taxa de respiração e esforço durante a cirurgia, pelo menos a cada 5 min. Siga específica Animal Care Institucional e Comitê de Uso e diretrizes veterinários para monitorar anestesia roedor. </li></ol></li><li> Aplicar uma gota de lubrificante oftálmica em cada olho utilizando uma zaragatoa estéril, a fim de evitar a secura. A administração de anti-inflamatório e analgésico para aliviar o desconforto é recomendado. </li><li> Com o animal deitado de costas, manter a anestesia utilizando um cone de nariz. </li><li> Limpar a área do pescoço do animal, limpando a área três vezes com etanol a 70% e cloro-hexidina. Shave área de cirurgia do animal usando uma lâmina de barbear (detalhada abaixo). </li></ol> 2. A dissecção da artéria carótida comum (CCA) <ol><li> Execute o procedimento de microcirurgia inteira sob um microscópio estereoscópico. Utilizando uma tesoura cirúrgica e fórceps executar uma incisão na linha média raso no pescoço, a partir de cima do esterno até abaixo tele maxila (cerca de 3 a 4 cm). </li><li> Utilizando uma pinça gordos cuidadosamente separado e tecido conjuntivo para expor a traqueia. </li><li> Coloque um travesseiro (objeto redondo, cerca de 0,5 cm de diâmetro) na parte de trás do pescoço do rato para estender o pescoço, expondo ainda mais a área. </li><li> Separa-se o tecido utilizando um afastador de tecido ou ganchos. </li><li> No lado esquerdo do animal, da traqueia, cuidadosamente pinça para além do tecido conjuntivo para expor a CCA esquerda. </li><li> Usando fórceps cuidadosamente remover todo o tecido conjuntivo para expor a bifurcação CCA, e o início de ambas as artérias carótidas interna e externa. </li></ol> 3. Preparação do CCA para perfusão Substância <ol><li> Insira dois segmentos de fio de náilon (cerca de 1 cm cada) sob artéria carótida externa (ECA), usando uma pinça. </li><li> Coloque um nó permanente no ponto mais alto possível da ECA. </li><li> No ponto mais baixo possível da ECA, imediatamente acima da bifurcação CCA, lugarum nó removível. Este nó deve ser solto em comparação com o nó superior. </li><li> Feche a CCA usando um clipe de embarcação, no ponto mais baixo possível. </li><li> Fechar a artéria carótida interna (ICA), utilizando um grampo navio. </li><li> Usando microdissecção mola tesoura realizar um pequeno corte no ECA (cerca de 2 mm), entre os dois nós. </li></ol> 4. Infusion Substância via ICA <ol><li> Montar um sistema de infusão. Anexar 6 polegadas de tubulação capilar (dimensões ideais: 2,5 mm x 1,2 mm) para uma seringa de tuberculina contendo 250 ml da substância a ser infundido (drogas, patógenos, vesículas extracelulares, entre outros) e insira a ponta capilar suavemente para dentro da incisão realizada no passo 3.6. </li><li> Continue a deslizar para baixo o tubo capilar até atingir um ponto médio entre a bifurcação e o grampo de fecho do CCA. </li><li> Amarrar o nó ECA inferior. Verifique se o nó está solto o suficiente para permitir a fluidez capilar e apertado o suficiente para evitar leaking. </li><li> Remover clipe do ICA. </li><li> Gentilmente aplicar pressão para a substância pistão seringa permitindo a infusão de cerca de 10 l por segundo. </li></ol> 5. Procedimentos após a infusão <ol><li> Coloque o clipe de volta no ICA. </li><li> Remova cuidadosamente o tubo capilar. </li><li> Amarrar o nó ECA inferior completamente. </li><li> Remova clipes do ICA e do CCA. </li></ol> 6. Incisão Encerramento e cuidados pós-operatórios <ol><li> Remover afastador ou tecido ganchos e travesseiro. </li><li> área de sutura limpa utilizando solução salina estéril. </li><li> Fechar a incisão usando nylon sutura / agulha e fórceps. </li><li> Administrar anti-inflamatória e analgésica para aliviar o desconforto pós-operatório. </li><li> Coloque o animal na gaiola colocada na almofada de aquecimento durante pelo menos 1 h e recuperação do monitor. </li></ol>

<ol>
	<li>Chen, L., Swartz, K. R., Toborek, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vessel+microport+technique+for+applications+in+cerebrovascular+research.">Vessel microport technique for applications in cerebrovascular research.</a> J Neurosci Res. 87 (7), 1718-1727 (2009).</li><li>Frisella, W. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracranial+injection+of+recombinant+adeno-associated+virus+improves+cognitive+function+in+a+murine+model+of+mucopolysaccharidosis+type+VII.">Intracranial injection of recombinant adeno-associated virus improves cognitive function in a murine model of mucopolysaccharidosis type VII.</a> Mol Ther. 3 (3), 351-358 (2001).</li><li>Wei, L., Erinjeri, J. P., Rovainen, C. M., Woolsey, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collateral+growth+and+angiogenesis+around+cortical+stroke.">Collateral growth and angiogenesis around cortical stroke.</a> Stroke. 32 (9), 2179-2184 (2001).</li><li>Wu, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+delivery+of+methotrexate+to+epidermal+growth+factor+receptor-positive+brain+tumors+by+means+of+cetuximab+(IMC-C225)+dendrimer+bioconjugates.">Targeted delivery of methotrexate to epidermal growth factor receptor-positive brain tumors by means of cetuximab (IMC-C225) dendrimer bioconjugates.</a> Mol Cancer Ther. 5 (1), 52-59 (2006).</li><li>Pignataro, G., Studer, F. E., Wilz, A., Simon, R. P., Boison, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroprotection+in+ischemic+mouse+brain+induced+by+stem+cell-derived+brain+implants.">Neuroprotection in ischemic mouse brain induced by stem cell-derived brain implants.</a> J Cereb Blood Flow Metab. 27 (5), 919-927 (2007).</li><li>Sugiyama, Y., Kusuhara, H., Suzuki, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetic+and+biochemical+analysis+of+carrier-mediated+efflux+of+drugs+through+the+blood-brain+and+blood-cerebrospinal+fluid+barriers:+importance+in+the+drug+delivery+to+the+brain.">Kinetic and biochemical analysis of carrier-mediated efflux of drugs through the blood-brain and blood-cerebrospinal fluid barriers: importance in the drug delivery to the brain.</a> J Control Release. 62 (1-2), 179-186 (1999).</li><li>Pardridge, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug+and+gene+delivery+to+the+brain:+the+vascular+route.">Drug and gene delivery to the brain: the vascular route.</a> Neuron. 36 (4), 555-558 (2002).</li><li>Vantyghem, S. A., Postenka, C. O., Chambers, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estrous+cycle+influences+organ-specific+metastasis+of+B16F10+melanoma+cells.">Estrous cycle influences organ-specific metastasis of B16F10 melanoma cells.</a> Cancer Res. 63 (16), 4763-4765 (2003).</li><li>Huang, R. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+gene+delivery+targeted+to+the+brain+using+a+transferrin-conjugated+polyethyleneglycol-modified+polyamidoamine+dendrimer.">Efficient gene delivery targeted to the brain using a transferrin-conjugated polyethyleneglycol-modified polyamidoamine dendrimer.</a> FASEB J. 21 (4), 1117-1125 (2007).</li><li>Liu, R., Martuza, R. L., Rabkin, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intracarotid+delivery+of+oncolytic+HSV+vector+G47Delta+to+metastatic+breast+cancer+in+the+brain.">Intracarotid delivery of oncolytic HSV vector G47Delta to metastatic breast cancer in the brain.</a> Gene Ther. 12 (8), 647-654 (2005).</li><li>Kumar, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transvascular+delivery+of+small+interfering+RNA+to+the+central+nervous+system.">Transvascular delivery of small interfering RNA to the central nervous system.</a> Nature. 448 (7149), 39-43 (2007).</li><li>Wrobel, J. K., Wolff, G., Xiao, R., Power, R. F., Toborek, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dietary+Selenium+Supplementation+Modulates+Growth+of+Brain+Metastatic+Tumors+and+Changes+the+Expression+of+Adhesion+Molecules+in+Brain+Microvessels.">Dietary Selenium Supplementation Modulates Growth of Brain Metastatic Tumors and Changes the Expression of Adhesion Molecules in Brain Microvessels.</a> Biol Trace Elem Res. , (2015).</li></ol>

The authors have nothing to disclose.

A microcirurgia infusão descrito aqui tem provado ser muito bem sucedida no fornecimento de substâncias exógenas de vários recursos biológicos para o SNC, impedindo a divulgação indesejada por todo o corpo 1, 12. O rompimento da barreira sangue-cérebro é uma característica patológica de várias doenças relacionadas com o SNC; Por conseguinte, a avaliação da relação de substâncias exógenas com a barreira hemato-encefálica é de grande importân...

Em modelos in vivo do sistema nervoso central (SNC) doenças requerem uma entrega eficaz de substâncias exógenas, tais como drogas, agentes patogénicos, ou exossomas, para o cérebro. Por isso, um método de entrega ideal deve causar o mínimo de trauma para o animal, preservar a integridade da rede neuronal, e alcançar concentrações elevadas de substâncias no cérebro 1. Vários métodos cirúrgicos de distribuição de substâncias locais foram descritos, incluindo intra-bainha, intracerebral, e as injeções intraventricular ou implantes 2, 3, 4, 5. Estas abordagens, no entanto, são consideradas traumática do sistema nervoso central, e permitir a administração de apenas baixos volumes de a substância de interesse. Além disso, tem sido sugerido que as substâncias exógenas podem ser rapidamente removidos pelo fluido cerebrospinal 6 </s-se&gt;, e uma gama baixa de penetração para o parênquima cerebral foi observada 7 quando as técnicas acima mencionadas são empregues. Métodos de entrega sistêmicas, tais como oral, pulmonar, subcutânea e intravenosa, são mais comumente usados em modelos animais, embora eles apresentam baixa eficácia na entrega das substâncias para o SNC, devido à absorção por outros órgãos 8, 9. Portanto, estas vias de administração requerem doses elevadas de substâncias administradas, aumentando o risco de efeitos colaterais e toxicidade 10, 11. Aqui, descrevemos uma técnica de microcirurgia infusão do mouse, o que efetivamente fornece substâncias diretamente no cérebro através da artéria carótida interna. Além de direccionamento da entrega ao CNS, esta técnica não ultrapassar barreiras fisiológicas normais e é portanto altamente relevantes para biological processos envolvidos nas passagens de agentes terapêuticos ou agentes patogénicos para o cérebro.

<table><tbody><tr><td>Anesthesia instrument</td><td>Vetequip</td><td>901806</td><td></td></tr><tr><td>Surgical scissors</td><td>Fine Science Tool</td><td>14558-09</td><td></td></tr><tr><td>Surgical forceps straight tip</td><td>Fine Science Tool</td><td>00108-11</td><td></td></tr><tr><td>Surgical forceps angled tip</td><td>Fine Science Tool</td><td>00109-11</td><td></td></tr><tr><td>Spring scissors</td><td>Fine Science Tool</td><td>15000-08</td><td></td></tr><tr><td>Nylon suture</td><td>Braintree Scientific</td><td>SUT-S 104</td><td></td></tr><tr><td>Capillary tubing (Micro-Renathane 0.010&amp;rdquo; x 0.005&amp;rdquo; per ft.)&amp;nbsp;</td><td>Braintree Scientific</td><td>MRE01050</td><td></td></tr><tr><td>Closing suture</td><td>VWR</td><td>95057-036</td><td></td></tr><tr><td>Isoflurane</td><td>Piramal</td><td></td><td></td></tr><tr><td>2,3,5-Triphenyltetrazolium chloride</td><td>FisherScientific</td><td>50-121-8005</td><td></td></tr></tbody></table>

mouse microsurgery infusion technique for targeted substance delivery into the cns via the internal carotid artery

Animal models of central nervous system (CNS) diseases and, consequently, blood-brain barrier disruption diseases, require the delivery of exogenous substances into the brain. These exogenous substances may induce injurious impact or constitute therapeutic strategy. The most common delivery methods of exogenous substances into the brain are based on systemic deliveries, such as subcutaneous or intravenous routes. Although commonly used, these approaches have several limitations, including low delivery efficacy into the brain. In contrast, surgical methods that locally deliver substances into the CNS are more specific and prevent the uptake of the exogenous substances by other organs. Several surgical methods for CNS delivery are available; however, they tend to be very traumatic. Here, we describe a mouse infusion microsurgery technique, which effectively delivers substances into the brain via the internal carotid artery, with minimal trauma and no interference with normal CNS functionality.

A técnica de microcirurgia infusão rato aqui descrito é muito versátil e tem sido usado para fornecer substâncias diferentes diretamente no cérebro, incluindo a entrega de células de tumor em um modelo representativo da formação de metástases cerebrais 1, 12. Esta técnica também é adequado para avaliar os aspectos patológicos de diferentes agentes patogé...

Watch this Scientific Journal Video about Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery at JoVE.com

Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery

The present protocol describes a mouse microsurgery infusion technique, which effectively delivers substances directly into the brain via the internal carotid artery.

Técnica do mouse Microcirurgia de infusão para distribuição de substâncias alvejado no SNC<i&gt; via</i&gt; Artéria carótida interna

Animal models of central nervous system (CNS) diseases and, consequently, blood-brain barrier disruption diseases, require the delivery of exogenous ...

mouse-microsurgery-infusion-technique-for-targeted-substance-delivery

Universidad de Cartagena UDEC

Research

JoVE Journal

Neuroscience

Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery

10.9K visualizações.  University of Miami. The present protocol describes a mouse microsurgery infusion technique, which effectively delivers substances directly into the brain via the internal carotid artery.

Vídeo: Mouse Microsurgery Infusion Technique for Targeted Substance Delivery into the CNS via the Internal Carotid Artery

Intracarotid Cancer Cell Injection to Produce Mouse Models of Brain Metastasis

Metastasis, the spread and growth of malignant cells at secondary sites within a patient&#39;s body, accounts for &#62; 90% of cancer-related mortality. Recently, impressive advances in novel therapies have dramatically prolonged survival and improved quality of life for many cancer patients. Sadly, incidence of brain metastatic recurrences is fast rising, and all current therapies are merely palliative. Hence, good experimental animal models are urgently needed to facilitate in-depth studies of the disease biology and to assess novel therapeutic regimens for preclinical evaluation. However, the standard in vivo metastasis assay via tail vein injection of cancer cells produces predominantly lung metastatic lesions; animals usually succumb to the lung tumor burden before any meaningful outgrowth of brain metastasis. Intracardiac injection of tumor cells produces metastatic lesions to multiple organ sites including the brain; however, the variability of tumor growth produced with this model is large, dampening its utility in evaluating therapeutic efficacy. To generate reliable and consistent animal models for brain metastasis study, here we describe a procedure for producing experimental brain metastasis in the house mouse (Mus musculus) via intracarotid injection of tumor cells. This approach allows one to produce large number of brain metastasis-bearing mice with similar growth and mortality characteristics, thus facilitating research efforts to study basic biological mechanisms and to assess novel therapeutic agents.

Brain metastasis has become an urgent unmet medical need as its incidence has increased while therapeutic options have remained palliative. Creating experimental animal models of brain metastasis via intracarotid arterial injection of cancer cells facilitates mechanistic studies of the disease biology and evaluation of novel intervention regimens.

Intracarotídeo injeção de células de cancer para produzir mouse modelos de metástases cerebrais

Metastasis, the spread and growth of malignant cells at secondary sites within a patient&#39;s body, accounts for &#62; 90% of cancer-related mortality. ...

Pesquisa do câncer

Targeting of Deep Brain Structures with Microinjections for Delivery of Drugs, Viral Vectors, or Cell Transplants

Microinjections into the brain parenchyma are important procedures to deliver drugs, viral vectors or cell transplants.  The brain lesion that an injecting needle produces during its trajectory is a major concern especially in the mouse brain for not only the brain is small but also sometimes multiple injections are needed.  We show here a method to produce glass capillary needles with a 50-&mu;m lumen which significantly reduces the brain damage and allows a precise targeting into the rodent brain. This method allows a delivery of small volumes (from 20 to 100 nl), reduces bleeding risks, and minimizes passive diffusion of drugs into the brain parenchyma. By using different size of capillary glass tubes, or changing the needle lumen, several types of substances and cells can be injected. Microinjections with a glass capillary tube represent a significant improvement in injection techniques and deep brain targeting with minimal collateral damage in small rodents.

In this article, we show a method to make glass capillary needles with a 50-&mu;m lumen. This technique significantly reduces the brain damage, minimizes passive diffusion of drugs and allows a precise targeting into the rodent brain.

Segmentação de estruturas cerebrais profundas com Microinjeções para entrega de drogas, vetores virais, ou Transplantes de Células

Microinjections into the brain parenchyma are important procedures to deliver drugs, viral vectors or cell transplants.  The brain lesion that an ...

Neurociência

Construction and Implantation of a Microinfusion System for Sustained Delivery of Neuroactive Agents.

Sustained delivery of neuroactive agents is widely used in neuroscience, but poses many technical challenges. It is necessary to deliver the agent with high precision while minimizing localized trauma and inflammation. Also, the ability to customize the system to accommodate animals of different species and sizes is desirable. This video presentation demonstrates the construction of an infusion system that can be fitted to any particular research animal. The delivery microcannula diameter is approximately 10-fold smaller than most infusion cannulas presently used. This translates into enhanced accuracy and reduced trauma to the brain region under study. The delivery cannula can also be sculpted to fit the contour of the surface of the animal's skull, thereby allowing closure of the scalp incision neatly over the infusion system, precluding the need for a skull-mounted pedestal, reducing risk of infection, and ensuring a greater level of comfort to the animal. The system is assembled in an air-free environment and requires the researcher to fashion glass micropipettes with a heat source. These construction methods require special skills that are best acquired, if not in person, using video instruction.  (This article is based on work first reported in J Neurosci Methods. 2008 Jan 30;167(2):213-20. Epub 2007 Aug 28.).

As neuroscience inquiry becomes more sophisticated, investigation of brain structures and circuitry requires improved levels of accuracy and higher resolution. We have developed a method for the preparation and implantation of a chronic infusion system within the brain utilizing a borosilicate microcannula with a tip diameter of 50 microns.

Construção e Implantação de um Sistema de Microinfusion para entrega Sustentada de Agentes neuroativos.

Sustained delivery of neuroactive agents is widely used in neuroscience, but poses many technical challenges. It is necessary to deliver the agent with ...

Biologia

Mouse Model of Intraluminal MCAO: Cerebral Infarct Evaluation by Cresyl Violet Staining

Stroke is the third cause of mortality and the leading cause of disability in the World. Ischemic stroke accounts for approximately 80% of all strokes. However, the thrombolytic tissue plasminogen activator (tPA) is the only treatment of acute ischemic stroke that exists. This led researchers to develop several ischemic stroke models in a variety of species. Two major types of rodent models have been developed: models of global cerebral ischemia or focal cerebral ischemia. To mimic ischemic stroke in patients, in whom approximately 80% thrombotic or embolic strokes occur in the territory of the middle cerebral artery (MCA), the intraluminal middle cerebral artery occlusion (MCAO) model is quite relevant for stroke studies. This model was first developed in rats by Koizumi et al. in 1986 1. Because of the ease of genetic manipulation in mice, these models have also been developed in this species 2-3.
	Herein, we present the transient MCA occlusion procedure in C57/Bl6 mice. Previous studies have reported that physical properties of the occluder such as tip diameter, length, shape, and flexibility are critical for the reproducibility of the infarct volume 4. Herein, a commercial silicon coated monofilaments (Doccol Corporation) have been used. Another great advantage is that this monofilament reduces the risk to induce subarachnoid hemorrhages. Using the Zeiss stereo-microscope Stemi 2000, the silicon coated monofilament was introduced into the internal carotid artery (ICA) via a cut in the external carotid artery (ECA) until the monofilament occludes the base of the MCA. Blood flow was restored 1 hour later by removal of the monofilament to mimic the restoration of blood flow after lysis of a thromboembolic clot in humans. The extent of cerebral infarct may be evaluated first by a neurologic score and by the measurement of the infarct volume. Ischemic mice were thus analyzed for their neurologic score at different post-reperfusion times. To evaluate the infarct volume, staining with 2,3,5-triphenyltetrazolium chloride (TTC) was usually performed. Herein, we used cresyl violet staining since it offers the opportunity to test many critical markers by immunohistochemistry. In this video, we report the MCAO procedure; neurological scores and the evaluation of the infarct volume by cresyl violet staining.

The intraluminal middle cerebral occlusion model in mice is herein presented. The extent of cerebral infarct is evaluated by a neurologic score and cresyl violet staining, an alternative staining to TTC, offering the great advantage to test in parallel many interest markers.

Modelo de Rato OACM Intraluminal: Avaliação infarto cerebral por coloração violeta Cresyl

Stroke is the third  cause of mortality and the leading cause of disability in the World. Ischemic  stroke accounts for approximately 80% of all strokes. ...

Medicina

Rat Model of Blood-brain Barrier Disruption to Allow Targeted Neurovascular Therapeutics

Endothelial cells with tight junctions along with the basement membrane and astrocyte end feet surround cerebral blood vessels to form the blood-brain barrier1. The barrier selectively excludes molecules from crossing between the blood and the brain based upon their size and charge. This function can impede the delivery of therapeutics for neurological disorders. A number of chemotherapeutic drugs, for example, will not effectively cross the blood-brain barrier to reach tumor cells2. Thus, improving the delivery of drugs across the blood-brain barrier is an area of interest.
The most prevalent methods for enhancing the delivery of drugs to the brain are direct cerebral infusion and blood-brain barrier disruption3. Direct intracerebral infusion guarantees that therapies reach the brain; however, this method has a limited ability to disperse the drug4. Blood-brain barrier disruption (BBBD) allows drugs to flow directly from the circulatory system into the brain and thus more effectively reach dispersed tumor cells. Three methods of barrier disruption include osmotic barrier disruption, pharmacological barrier disruption, and focused ultrasound with microbubbles. Osmotic disruption, pioneered by Neuwelt, uses a hypertonic solution of 25% mannitol that dehydrates the cells of the blood-brain barrier causing them to shrink and disrupt their tight junctions. Barrier disruption can also be accomplished pharmacologically with vasoactive compounds such as histamine5 and bradykinin6. This method, however, is selective primarily for the brain-tumor barrier7. Additionally, RMP-7, an analog of the peptide bradykinin, was found to be inferior when compared head-to-head with osmotic BBBD with 25% mannitol8. Another method, focused ultrasound (FUS) in conjunction with microbubble ultrasound contrast agents, has also been shown to reversibly open the blood-brain barrier9. In comparison to FUS, though, 25% mannitol has a longer history of safety in human patients that makes it a proven tool for translational research10-12.
In order to accomplish BBBD, mannitol must be delivered at a high rate directly into the brain's arterial circulation. In humans, an endovascular catheter is guided to the brain where rapid, direct flow can be accomplished. This protocol models human BBBD as closely as possible. Following a cut-down to the bifurcation of the common carotid artery, a catheter is inserted retrograde into the ECA and used to deliver mannitol directly into the internal carotid artery (ICA) circulation. Propofol and N2O anesthesia are used for their ability to maximize the effectiveness of barrier disruption13. If executed properly, this procedure has the ability to safely, effectively, and reversibly open the blood-brain barrier and improve the delivery of drugs that do not ordinarily reach the brain 8,13,14.

Blood-brain barrier disruption aids the delivery of certain drugs to the brain. Mannitol delivered intra-arterially shrinks cells surrounding blood vessels in order to physically disrupt the barrier.

Modelo de ratos de sangue-cérebro Rompimento de barreira para permitir alvejado Neurovascular Therapeutics

Endothelial cells with tight junctions along with the basement membrane and astrocyte end feet surround cerebral blood vessels to form the blood-brain ...

Modeling Brain Metastasis by Internal Carotid Artery Injection of Cancer Cells

Brain metastasis is a cause of severe morbidity and mortality in cancer patients. Critical aspects of metastatic diseases, such as the complex neural microenvironment and stromal cell interaction, cannot be entirely replicated with in vitro assays; thus, animal models are critical for investigating and understanding the effects of therapeutic intervention. However, most brain tumor xenografting methods do not produce brain metastases consistently in terms of the time frame and tumor burden. Brain metastasis models generated by intracardiac injection of cancer cells can result in unintended extracranial tumor burden and lead to non-brain metastatic morbidity and mortality. Although intracranial injection of cancer cells can limit extracranial tumor formation, it has several caveats, such as the injected cells frequently form a singular tumor mass at the injection site, high leptomeningeal involvement, and damage to brain vasculature during needle penetration. This protocol describes a mouse model of brain metastasis generated by internal carotid artery injection. This method produces intracranial tumors consistently without the involvement of other organs, enabling the evaluation of therapeutic agents for brain metastasis.

Brain metastasis is a cause of severe morbidity and mortality in cancer patients. Most brain metastasis mouse models are complicated by systemic metastases confounding analysis of mortality and therapeutic intervention outcomes. Presented here is a protocol for internal carotid injection of cancer cells that produces consistent intracranial tumors with minimal systemic tumors.

Modelagem de Metástases Cerebrais por Injeção de Células Cancerígenas na Artéria Carótida Interna

Brain metastasis is a cause of severe morbidity and mortality in cancer patients. Critical aspects of metastatic diseases, such as the complex neural ...

Heterotopic Mucosal Engrafting Procedure for Direct Drug Delivery to the Brain in Mice

Delivery of therapeutics into the brain is impeded by the presence of the blood-brain barrier (BBB) which restricts the passage of polar and high molecular weight compounds from the bloodstream and into brain tissue. Some direct delivery success in humans has been achieved via implantation of transcranial catheters; however this method is highly invasive and associated with numerous complications. A less invasive alternative would be to dose the brain through a surgically implanted, semipermeable membrane such as the nasal mucosa that is used to repair skull base defects following endoscopic transnasal tumor removal surgery in humans. Drug transfer though this membrane would effectively bypass the BBB and diffuse directly into the brain and cerebrospinal fluid. Inspired by this approach, a surgical approach in mice was developed that uses a donor septal mucosal membrane engrafted over an extracranial surgical BBB defect. This model has been shown to effectively allow the passage of high molecular weight compounds into the brain. Since numerous drug candidates are incapable of crossing the BBB, this model is valuable for performing preclinical testing of novel therapies for neurological and psychiatric diseases.

A mouse model of human endoscopic skull base reconstruction has been developed that creates a semipermeable interface between the brain and nose using nasal mucosal grafts. This method allows researchers to study delivery to the central nervous system of high molecular weight therapeutics which are otherwise excluded by the blood-brain barrier when administered systemically.

Heterotópico mucosa enxertando Procedimento para entrega da droga direto para o cérebro em ratos

Delivery of therapeutics into the brain is impeded by the presence of the blood-brain barrier (BBB) which restricts the passage of polar and high ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

Infusões artéria carótida para farmacocinéticas e farmacodinâmicas Análise de taxanos em Ratos

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

<meta charset="utf8"></head><body>Reparo da artéria carótida comum após injeção em um modelo de camundongo

Facilitating Repeat Intracarotid Injections in Mouse Models by a Novel Injection Site Repair Technique

Given recent advances in the delivery of novel antitumor therapeutics using endovascular selective intraarterial delivery methods in neuro-oncology, there is an urgent need to develop methods for intracarotid injections in mouse models, including methods to repair the carotid artery in mice after injection to allow for subsequent injections. We developed a method of intracarotid injection in a mouse model to deliver therapeutics into the internal carotid artery (ICA) with two alternative procedures. 
During injection, the needle is inserted into the common carotid artery (CCA) after tying a suture around the external carotid artery (ECA) and injected therapeutics are delivered into the ICA. Following injection, the common carotid artery (CCA) can be ligated, which limits the number of intracarotid injections to one. The alternative procedure described in this article includes a modification where intracarotid artery injection is followed by injection site repair of the CCA, which restores blood flow within the CCA and avoids the complication of cerebral ischemia seen in some mouse models. 
We also compared the delivery of bone marrow-derived human mesenchymal stem cells (BM-hMSCs) to intracranial tumors when delivered through intracarotid injection with and without injection site repair following the injection. Delivery of BM-hMSCs does not differ significantly between the methods. Our results demonstrate that injection site repair of the CCA allows for repeat injections through the same artery and does not impair the delivery and distribution of injected material, thus providing a model with greater flexibility that more closely emulates intracarotid injection in humans.

<meta charset="utf8"></head><body>Autor em destaque: Avançando no tratamento do glioblastoma por meio de estratégias de entrega intra-arterial para vírus oncolíticos e microRNAs

Repair of the intracarotid artery in a mouse model after injection returns blood flow to the artery without negatively impacting the distribution of the injected material. Injection site repair facilitates subsequent injections through the same artery and prevents cerebral ischemia in mouse strains that lack a complete Circle of Willis.

Facilitando injeções intracarotídeas repetidas em modelos de camundongos por uma nova técnica de reparo no local da injeção

Given recent advances in the delivery of novel antitumor therapeutics using endovascular selective intraarterial delivery methods in neuro-oncology, there ...

Técnica do mouse Microcirurgia de infusão para distribuição de substâncias alvejado no SNC

Resumo

Explore mais vídeos

Capítulos neste vídeo

Intracarotídeo injeção de células de cancer para produzir mouse modelos de metástases cerebrais

Segmentação de estruturas cerebrais profundas com Microinjeções para entrega de drogas, vetores virais, ou Transplantes de Células

Construção e Implantação de um Sistema de Microinfusion para entrega Sustentada de Agentes neuroativos.

Modelo de Rato OACM Intraluminal: Avaliação infarto cerebral por coloração violeta Cresyl

Modelo de ratos de sangue-cérebro Rompimento de barreira para permitir alvejado Neurovascular Therapeutics

Modelagem de Metástases Cerebrais por Injeção de Células Cancerígenas na Artéria Carótida Interna

Heterotópico mucosa enxertando Procedimento para entrega da droga direto para o cérebro em ratos

Infusões artéria carótida para farmacocinéticas e farmacodinâmicas Análise de taxanos em Ratos

Facilitando injeções intracarotídeas repetidas em modelos de camundongos por uma nova técnica de reparo no local da injeção

Facilitando injeções intracarotídeas repetidas em modelos de camundongos por uma nova técnica de reparo no local da injeção