The authors would like to thank John Marston for expert animal husbandry and Dr. Marco A. Passini for technical assistance at the early stages of this project. This work was funded by grant from the National Institutes of Health to C.L.L. (R01NS41584; R01HD054413).

1. Intracerebroventricular injection
<ol>
<li>The first step is the preparation of the injection stock solutions; these solutions are viral vector, plasmid DNA, drugs, and should be injected under sterile conditions. </li> 
<li>Mix a desired titer of viral vector (5-7 &mu;L total) with 0.05% w/v trypan blue in PBS for visualization of the injection site.</li>
<li>Plasmid DNA solution (5 l &mu;L total) contains D-(+)-glucose 20% (w/v) (1 &mu;L), trypan blue (0.05%) PBS (1 &mu;L), plasmid (&tilde;5 &tilde;g/&tilde;L) (2 &tilde;L), and 2.5 kDa linear PEI homopolymer (150 mM) (1 &tilde;L).</li> 
<li>Immobilize the PND 2 neonates via cryo-anesthesia for 1-2 minutes.</li>
<li>The needle used for this injection is a micro-liter calibrated sterilized glass micropipette that is attached to a 3ml 3 mL Hamilton syringe through a long tube.</li> 
<li>Break the tip of the needle (with spatula) to adjust for 2 mm penetration into the skull. Place the needle diagonally in the microcentrifuge tube containing the injection solution. Load the injection solution into the needle by carefully pulling the plunger of the syringe. </li>
<li>After the uptake of the solution, disassociate the syringe from the tube; pull the plunger up further and then attach to the needle again.</li>
<li>Hold the needle in right hand between the thumb and index fingers and place the syringe between the middle and ring fingers with the plunger touching the palm of the right hand.</li>
<li>Grasp the immobilized mouse firmly by the skin behind the head using the left hand and place on a fiber-optic light to illuminate relevant anatomical structures that can be used as a guide.</li>
<li>Insert the needle 2 mm deep, perpendicular to the skull surface, at a location approximately 0.25 mm lateral to the sagittal suture and 0.50&#x2013;0.75 mm rostral to the neonatal coronary suture (Figure 1A).Then, push the plunger using the palm of the right hand very slowly and carefully. Monitor for ruptured vessels or facial swelling.</li>
<li>Remove the needle 15 seconds after discontinuation of plunger movement to prevent backflow.</li>
<li>To recover, keep the mice for 5&#x2013;10 minutes in a warmed container until movement and general responsiveness is restored. </li>
</ol>
2. Intravenous injection via the temporal/facial vein
<ol>
<li>The solution to be injected should be prepared and supplemented with filtered green food dye at 1:100 dilution and injected under sterile conditions.</li>
<li>Attach a small plastic luer to the end of a 100 &mu;L glass Hamilton syringe. To the luer, attach a 33 gauge 0.25 inch hypodermic needle. Insure that all parts are securely connected. </li> 
<li>Load the syringe with the volume to be injected, ensuring that there is no air in the syringe as injection of air into the vessel is lethal. It is often helpful to pipet the volume to be injected unto a piece of parafilm. This allows for the clear visualization of uptake of the solution into the syringe. </li>
<li>A Wee Sight Transilluminator is used to easily visualize the superficial temporal vein, or facial vein, in the neonate (Figure 2A). Before injection, secure the neonate to the transilluminator using surgical tape. Gauze should be placed between the neonate and the tape to prevent the tape from damaging the skin of the animal. Secure the animal to the transilluminator on its side, ensuring that the tape does not prevent respiration. The neonate&#x2019;s neck should be gently turned so that the facial vein is easily visible and the nose should be taped to stabilize the head. </li>
<li>Using a 2.25X headband magnifier to allow for easier visualization, slowly insert the needle into the vein. The vein is very superficial so the needle should remain visible beneath the skin. </li>
<li>Slowly infuse the volume of solution into the vein. The green dye allows for easy visualization of the injection. </li>
<li>Wait 15 seconds before removing the needle as there is a lag between fully depressing the plunger of the syringe and the expulsion of the remaining solution due to the extremely narrow needle bore. </li>
<li>After removing the needle, use gauze to apply pressure to the injection site until the bleeding ceases.</li>
<li>Monitor the neonate for signs of distress. After a proper injection, no overt distress should be observed. The neonate should be given approximately 5 minutes to recover before it is returned to the cage.</li>
<li>Flush the needle/syringe unit with PBS in between injections as blood in the needle will quickly clog it due to small bore. </li>
</ol>
3. Representative results:
ICV injection: The brain can be harvested at different time points post-injection and visualized to demonstrate successful injection technique. If the dye is not added to the injection solution, it will be difficult to check for the accuracy of the injection. Proper injection of one of the ventricles will allow distribution of the trypan blue on the injected side of the brain approximately 10-15 minutes post-injection (Figure 1B). A uniform distribution of trypan blue in both right and left cerebral hemispheres and olfactory bulbs will be visible approximately 60 minutes post injection (Figure 1C). This is due to connectivity of the cerebral ventricles that will permit the dissemination of the blue dye to the adjacent ventricle. Accurate injections can also be visualized by dispersal of the blue dye in the rostral central spinal canal approximately within 12 hours post-injection (Figure 1D). Inaccurate injections can be distinguished by lack of blue color in cerebral hemispheres. In this case, the depth of the needle was not sufficient and the injection solution has probably distributed under the skin. An alternative possibility is that the needle penetrated too deep in the brain, thereby passing beyond the ventricle and the solution is emptied underneath the cerebral ventricles.
IV injection: Accurate and efficient temporal/facial vein injection can be visualized immediately following the injection. As the solution is injected, the green dye allows for the visualization of the solution entering and flowing through the facial vein (Figure 2A). Additionally, altered skin color of the mouse will be observed following injection. The neonate&#x2019;s normal pink color is converted to green, due to presence of green food dye in the injection solution (Figure 2B). The extent of the green color change observed in the neonate is dependent upon the concentration of dye used. For simple visualization of injection and during a practice period, a 1:50 dilution is recommended. However, the dramatically altered skin tone often results in the pup being rejected by the mother and therefore, removal of the dye or a significantly reduced concentration should be considered during experimental procedures. An inaccurate injection will result in the accumulation of green dye under the skin at the site of the injection. Incomplete injection, which occurs when the opening of the needle is not fully inserted within the vein, is seen when some solution flows in the vein and some accumulates under the skin. If this is observed, the needle should be inserted further into the vessel. 
<img src="/files/ftp_upload/2968/2968fig1.jpg" alt="Figure 1"/> Figure 1. Demonstration of successful I.C.V. injections in PDN2 mice. A) Schematic of injection sites utilized in I.C.V. injections into the ventricles. B) Brain from I.C.V. injected Pup with trypan blue in PBS on left ventricle, photo taken 15 minutes post injection. C) Brain from I.C.V. injected Pup with trypan blue in PBS on left ventricle, photo taken 60 minutes post injection. D) Rostral central spinal canal is shown in I.C.V. injected pup with trypan blue in PBS on left ventricle, photo taken 12 hours post injection.
<img src="/files/ftp_upload/2968/2968fig2.jpg" alt="Figure 2"/> Figure 2. Demonstration of successful I.V. injections in PDN2 mice. A) Schematic of facial vein utilized for I.V. injections. B) Pup injected I.V. with green dye in PBS compared to un-injected littermate, Photo taken immediately post injection.

<ol>
	<li>Blanchette, M., Fortin, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood-brain+barrier+disruption+in+the+treatment+of+brain+tumors.">Blood-brain barrier disruption in the treatment of brain tumors.</a> Methods Mol. Biol. 686, 447-463 (2011).</li><li>Foust, K. D., Kaspar, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Over+the+barrier+and+through+the+blood:+to+CNS+delivery+we+go.">Over the barrier and through the blood: to CNS delivery we go.</a> Cell Cycle. 24, 4017-4018 (2009).</li><li>Snyder, E. Y., Taylor, R. M., Wolfe, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+progenitor+cell+engraftment+corrects+lysosomal+storage+throughout+the+MPS+VII+mouse+brain.">Neural progenitor cell engraftment corrects lysosomal storage throughout the MPS VII mouse brain.</a> Nature. 374, 367-370 (1995).</li><li>Passini, M. A., Wolfe, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Widespread+gene+delivery+and+structure-specific+patterns+of+expression+in+the+brain+after+intraventricular+injections+of+neonatal+mice+with+an+adeno-associated+virus+vector.">Widespread gene delivery and structure-specific patterns of expression in the brain after intraventricular injections of neonatal mice with an adeno-associated virus vector.</a> J. Virol. 24, 12382-12392 (2001).</li><li>Kienstra, K. A., Freysdottir, D., Gonzales, N. M., Hirschi, K. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+neonatal+intravascular+injections:+modeling+newborn+disease.">Murine neonatal intravascular injections: modeling newborn disease.</a> J. Am. Assoc. Lab. Anim. Sci. 46, 50-54 (2007).</li><li>Sands, M. S., Barker, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percutaneous+intravenous+injection+in+neonatal+mice.">Percutaneous intravenous injection in neonatal mice.</a> Lab. Anim. Sci. 49, 328-330 (1999).</li><li>Foust, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rescue+of+the+spinal+muscular+atrophy+phenotype+in+a+mouse+model+by+early+postnatal+delivery+of+SMN.">Rescue of the spinal muscular atrophy phenotype in a mouse model by early postnatal delivery of SMN.</a> Nat. Biotechnol. 28, 271-274 (2010).</li><li>Foust, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravascular+AAV9+preferentially+targets+neonatal+neurons+and+adult+astrocytes.">Intravascular AAV9 preferentially targets neonatal neurons and adult astrocytes.</a> Nat. Biotechnol. 27, 59-65 (2009).</li><li>Passini, M. A., Watson, D. J., Wolfe, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gene+delivery+to+the+mouse+brain+with+adeno-associated+virus.">Gene delivery to the mouse brain with adeno-associated virus.</a> Methods Mol. Biol. 246, 225-236 (2004).</li><li>Coady, T. H., Lorson, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trans-splicing-mediated+improvement+in+a+severe+mouse+model+of+spinal+muscular+atrophy.">Trans-splicing-mediated improvement in a severe mouse model of spinal muscular atrophy.</a> J. Neurosci. 30, 126-130 (2010).</li><li>Baughan, T. D., Dickson, A., Osman, E. Y., Lorson, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delivery+of+bifunctional+RNAs+that+target+an+intronic+repressor+and+increase+SMN+levels+in+an+animal+model+of+spinal+muscular+atrophy.">Delivery of bifunctional RNAs that target an intronic repressor and increase SMN levels in an animal model of spinal muscular atrophy.</a> Hum. Mol. Genet. 18, 1600-1611 (2009).</li><li>Coady, T. H., Baughan, T. D., Shababi, M., Passini, M. A., Lorson, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+single+vector+system+that+enhances+trans-splicing+of+SMN2+transcripts.">Development of a single vector system that enhances trans-splicing of SMN2 transcripts.</a> PLoS One. 3, e3468-e3468 (2008).</li><li>Dickson, A., Osman, E., Lorson, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Negatively-Acting+Bifunctional+RNA+Increases+Survival+Motor+Neuron+in+vitro+and+in+vivo.">Negatively-Acting Bifunctional RNA Increases Survival Motor Neuron in vitro and in vivo.</a> Hum. Gene. Ther. 19, 1307-1315 .</li><li>Mattis, V. B., Ebert, A. D., Fosso, M. Y., Chang, C. W., Lorson, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Delivery+of+a+read-through+inducing+compound,+TC007,+lessens+the+severity+of+a+spinal+muscular+atrophy+animal+model.">Delivery of a read-through inducing compound, TC007, lessens the severity of a spinal muscular atrophy animal model.</a> Hum. Mol. Genet. 18, 3906-3913 (2009).</li><li>Williams, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oligonucleotide-mediated+survival+of+motor+neuron+protein+expression+in+CNS+improves+phenotype+in+a+mouse+model+of+spinal+muscular+atrophy.">Oligonucleotide-mediated survival of motor neuron protein expression in CNS improves phenotype in a mouse model of spinal muscular atrophy.</a> J. Neurosci. 29, 7633-7638 (2009).</li><li>Passini, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CNS-targeted+gene+therapy+improves+survival+and+motor+function+in+a+mouse+model+of+spinal+muscular+atrophy.">CNS-targeted gene therapy improves survival and motor function in a mouse model of spinal muscular atrophy.</a> J. Clin. Invest. 120, 1253-1264 (2010).</li><li>Shababi, M., Glascock, J., Lorson, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Combination+of+SMN+Trans-Splicing+and+a+Neurotrophic+Factor+Increases+the+Life+Span+and+Body+Mass+in+a+Severe+Model+of+Spinal+Muscular+Atrophy.">Combination of SMN Trans-Splicing and a Neurotrophic Factor Increases the Life Span and Body Mass in a Severe Model of Spinal Muscular Atrophy.</a> Hum. Gene. Ther. 22, 1-10 (2010).</li></ol>

No conflicts of interest declared.

Research using mouse models of disease often requires the administration of drugs or other substances to neonates. In this video, we demonstrate the step-by step procedures involving two types of injection strategies that can be used to target the CNS: 1) direct injection into the CNS utilizing intracerebroventricular (ICV) injection; or 2) IV injection targeting the temporal/facial vein. The timing of these injections is of great importance. Since the ICV injections are freehand, the skull must be relatively malleable. ...

<table border="1">
	<tbody>
		<tr>
			<th>Name of the reagent</th>
			<th>Company</th>
			<th>Catalogue number</th>
			<th>Comments (optional)</th>
		</tr>
		<tr>
			<td>Green Food Dye</td>
			<td>McCormick</td>
			<td>n/a</td>
			<td>Must be filtered</td>
		</tr>
		<tr>
			<td>Hamilton Glass Syringe (100 &mu;L)</td>
			<td>Sigma Aldrick</td>
			<td>20702</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>LuerMxF Thread Style White Nylon</td>
			<td>Small Parts, Inc.</td>
			<td>VPLF-LC78-1-25</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Fine gauge Hypodermic Needles</td>
			<td>Popper</td>
			<td>7111</td>
			<td>Size: 33(SWG) x &frac14;" (6.35 MM)</td>
		</tr>
		<tr>
			<td>Wee Sight Transilluminator</td>
			<td>Respironics</td>
			<td>1017920</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>2.25X Headband Magnifier</td>
			<td>MagEyes</td>
			<td>Model No. 5</td>
			<td>Select magnification to fit individual preferences</td>
		</tr>
	</tbody>
</table>

delivery of therapeutic agents through intracerebroventricular (icv) and intravenous (iv) injection in mice

Despite the protective role that blood brain barrier plays in shielding the brain, it limits the access to the central nervous system (CNS) which most often results in failure of potential therapeutics designed for neurodegenerative disorders 1,2. Neurodegenerative diseases such as Spinal Muscular Atrophy (SMA), in which the lower motor neurons are affected, can benefit greatly from introducing the therapeutic agents into the CNS. The purpose of this video is to demonstrate two different injection paradigms to deliver therapeutic materials into neonatal mice soon after birth. One of these methods is injecting directly into cerebral lateral ventricles (Intracerebroventricular) which results in delivery of materials into the CNS through the cerebrospinal fluid 3,4. The second method is a temporal vein injection (intravenous) that can introduce different therapeutics into the circulatory system, leading to systemic delivery including the CNS 5. Widespread transduction of the CNS is achievable if an appropriate viral vector and viral serotype is utilized. Visualization and utilization of the temporal vein for injection is feasible up to postnatal day 6. However, if the delivered material is intended to reach the CNS, these injections should take place while the blood brain barrier is more permeable due to its immature status, preferably prior to postnatal day 2. The fully developed blood brain barrier greatly limits the effectiveness of intravenous delivery. Both delivery systems are simple and effective once the surgical aptitude is achieved. They do not require any extensive surgical devices and can be performed by a single person. However, these techniques are not without challenges. The small size of postnatal day 2 pups and the subsequent small target areas can make the injections difficult to perform and initially challenging to replicate.

Watch this Scientific Journal Video about Delivery of Therapeutic Agents Through Intracerebroventricular ICV and Intravenous IV Injection in Mice at JoVE.com

Delivery of Therapeutic Agents Through Intracerebroventricular ICV and Intravenous IV Injection in Mice

This article demonstrates two very different methods of injection: 1) into the brain (intracerebroventricular) and 2) systemic (intravenous) to introduce the therapeutic agents into the central nervous system of neonatal mice.

Delivery of Therapeutic Agents Through Intracerebroventricular (ICV) and Intravenous (IV) Injection in Mice

Despite the protective role that blood brain barrier plays in shielding the brain, it limits the access to the central nervous system (CNS) which most ...

delivery-therapeutic-agents-through-intracerebroventricular-icv

Research

JoVE Journal

Medicine

59.2K Views.  University of Missouri. Questo articolo viene illustrato due metodi molto diversi di iniezione: 1) nel cervello (intracerebroventricolare) e 2) sistemica (endovenosa) per introdurre gli agenti terapeutici nel sistema nervoso centrale di topi neonati.

Video: Delivery of Therapeutic Agents Through Intracerebroventricular ICV and Intravenous IV Injection in Mice

Orthotopic Xenografting of Human Luciferase-Tagged Malignant Peripheral Nerve Sheath Tumor Cells for in vivo Testing of Candidate Therapeutic Agents

Although in vitro screens are essential for the initial identification of candidate therapeutic agents, a rigorous assessment of the drug's ability to inhibit tumor growth must be performed in a suitable animal model. The type of animal model that is best for this purpose is a topic of intense discussion. Some evidence indicates that preclinical trials examining drug effects on tumors arising in transgenic mice are more predictive of clinical outcome1and so candidate therapeutic agents are often tested in these models. Unfortunately, transgenic models are not available for many tumor types. Further, transgenic models often have other limitations such as concerns as to how well the mouse tumor models its human counterpart, incomplete penetrance of the tumor phenotype and an inability to predict when tumors will develop.
Consequently, many investigators use xenograft models (human tumor cells grafted into immunodeficient mice) for preclinical trials if appropriate transgenic tumor models are not available. Even if transgenic models are available, they are often partnered with xenograft models as the latter facilitate rapid determination of therapeutic ranges. Further, this partnership allows a comparison of the effectiveness of the agent in transgenic tumors and genuine human tumor cells. Historically, xenografting has often been performed by injecting tumor cells subcutaneously (ectopic xenografts). This technique is rapid and reproducible, relatively inexpensive and allows continuous quantitation of tumor growth during the therapeutic period2. However, the subcutaneous space is not the normal microenvironment for most neoplasms and so results obtained with ectopic xenografting can be misleading due to factors such as an absence of organ-specific expression of host tissue and tumor genes. It has thus been strongly recommended that ectopic grafting studies be replaced or complemented by studies in which human tumor cells are grafted into their tissue of origin (orthotopic xenografting)2. Unfortunately, implementation of this recommendation is often thwarted by the fact that orthotopic xenografting methodologies have not yet been developed for many tumor types.
Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive sarcomas that occur sporadically or in association with neurofibromatosis type 13and most commonly arise in the sciatic nerve4. Here we describe a technically straightforward method in which firefly luciferase-tagged human MPNST cells are orthopically xenografted into the sciatic nerve of immunodeficient mice. Our approach to assessing the success of the grafting procedure in individual animals and subsequent non-biased randomization into study groups is also discussed.

Orthotopic Xenografting of Human Luciferase-Tagged Malignant Peripheral Nerve Sheath Tumor Cells for in vivo Testing of Candidate Therapeutic Agents

A method for reliably grafting luciferase-tagged human malignant peripheral nerve sheath tumor cells into the sciatic nerve of immunodeficient mice is described. The use of bioluminescence imaging to demonstrate proper establishment of tumor grafts and criteria for random segregation of animals into study groups are also discussed.

Although in vitro screens are essential for the initial identification of candidate therapeutic agents, a rigorous assessment of the drug's ability to ...

Slow-release Drug Delivery through Elvax 40W to the Rat Retina: Implications for the Treatment of Chronic Conditions

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these diseases. Chronic retinal diseases such as retinal oedema or neovascularization usually require multiple intraocular injections to effectively treat the condition. However, the risks associated with these injections increase with repeated delivery of the drug. Therefore, alternative delivery methods need to be established in order to minimize the risks of reinjection. Several other investigations have developed methods to deliver drugs over extended time, through materials capable of releasing chemicals slowly into the eye. In this investigation, we outline the use of Elvax 40W, a copolymer resin, to act as a vehicle for drug delivery to the adult rat retina. The resin is made and loaded with the drug. The drug-resin complex is then implanted into the vitreous cavity, where it will slowly release the drug over time. This method was tested using 2-amino-4-phosphonobutyrate (APB), a glutamate analogue that blocks the light response of the retina. It was demonstrated that the APB was slowly released from the resin, and was able to block the retinal response by 7 days after implantation. This indicates that slow-release drug delivery using this copolymer resin is effective for treating the retina, and could be used therapeutically with further testing.

This paper details how Elvax 40W can be used as a slow-release method for drug delivery to the adult rat retina. The protocol for preparing, loading, and delivering the drug-resin complex to the eye is described.

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these ...

Ultrasound-guided Transthoracic Intramyocardial Injection in Mice

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. Experiments involving myocardial injection are currently performed by direct surgical access through a thoracotomy. While convenient when performed at the time of another experimental manipulation such as coronary artery ligation, the need for an invasive procedure for intramyocardial delivery limits potential experimental designs. With ever improving ultrasound resolution and advanced noninvasive imaging modalities, it is now feasible to routinely perform ultrasound-guided, percutaneous intramyocardial injection. This modality efficiently and reliably delivers agents to a targeted region of myocardium. Advantages of this technique include the avoidance of surgical morbidity, the facility to target regions of myocardium selectively under ultrasound guidance, and the opportunity to deliver injectate to the myocardium at multiple, predetermined time intervals. With practiced technique, complications from intramyocardial injection are rare, and mice quickly return to normal activity on recovery from anesthetic. Following the steps outlined in this protocol, the operator with basic echocardiography experience can quickly become competent in this versatile, minimally invasive technique.

Echocardiography-guided percutaneous intramyocardial injection represents an efficient, reliable, and targetable modality for the delivery of gene transfer agents or cells into the murine heart. Following the steps outlined in this protocol, the operator can quickly become competent in this versatile, minimally invasive technique.

Murine models of cardiovascular disease are important for investigating pathophysiological mechanisms and exploring potential regenerative therapies. ...

High Throughput Characterization of Adult Stem Cells Engineered for Delivery of Therapeutic Factors for Neuroprotective Strategies

Mesenchymal stem cells (MSCs) derived from bone marrow are a powerful cellular resource and have been used in numerous studies as potential candidates to develop strategies for treating a variety of diseases. The purpose of this study was to develop and characterize MSCs as cellular vehicles engineered for delivery of therapeutic factors as part of a neuroprotective strategy for rescuing the damaged or diseased nervous system. In this study we used mouse MSCs that were genetically modified using lentiviral vectors, which encoded brain-derived neurotrophic factor (BDNF) or glial cell-derived neurotrophic factor (GDNF), together with green fluorescent protein (GFP). 
Before proceeding with in vivo transplant studies it was important to characterize the engineered cells to determine whether or not the genetic modification altered aspects of normal cell behavior. Different culture substrates were examined for their ability to support cell adhesion, proliferation, survival, and cell migration of the four subpopulations of engineered MSCs. High content screening (HCS) was conducted and image analysis performed. 
Substrates examined included: poly-L-lysine, fibronectin, collagen type I, laminin, entactin-collagen IV-laminin (ECL). Ki67 immunolabeling was used to investigate cell proliferation and Propidium Iodide staining was used to investigate cell viability. Time-lapse imaging was conducted using a transmitted light/environmental chamber system on the high content screening system.
Our results demonstrated that the different subpopulations of the genetically modified MSCs displayed similar behaviors that were in general comparable to that of the original, non-modified MSCs. The influence of different culture substrates on cell growth and cell migration was not dramatically different between groups comparing the different MSC subtypes, as well as culture substrates. 
This study provides an experimental strategy to rapidly characterize engineered stem cells and their behaviors before their application in long-term in vivo transplant studies for nervous system rescue and repair.

This study describes an experimental platform to rapidly characterize engineered stem cells and their behaviors before their application in long-term in vivo transplant studies for nervous system rescue and repair.

Mesenchymal stem cells (MSCs) derived from bone marrow are a powerful cellular resource and have been used in numerous studies as potential candidates to ...

Testing the Efficacy of Pharmacological Agents in a Pericardial Target Delivery Model in the Swine

To date, many pharmacological agents used to treat or prevent arrhythmias in open-heart cases create undesired systemic side effects. For example, antiarrhythmic drugs administered intravenously can produce drops in systemic pressure in the already compromised cardiac patient. While performing open-heart procedures, surgeons will often either create a small port or form a pericardial cradle to create suitable fields for operation. This access yields opportunities for target pharmacological delivery (antiarrhythmic or ischemic preconditioning agents) directly to the myocardial tissue without undesired side effects.
We have developed a swine model for testing pharmacological agents for target delivery within the pericardial fluid. While fully anesthetized, each animal was instrumented with a Swan-Ganz catheter as well as left and right ventricle pressure catheters, and pacing leads were placed in the right atrial appendage and the right ventricle. A medial sternotomy was then performed and a pericardial access cradle was created; a plunge pacing lead was placed in the left atrial appendage and a bipolar pacing lead was placed in the left ventricle. Utilizing a programmer and a cardiac mapping system, the refractory period of the atrioventricular node (AVN), atria and ventricles was determined. In addition, atrial fibrillation (AF) induction was produced utilizing a Grass stimulator and time in AF was observed. These measurements were performed prior to treatment, as well as 30 min&#160;and 60 min&#160;after pericardial treatment. Additional time points were added for selected studies. The heart was then cardiopleged and reanimated in a four chamber working mode. Pressure measurements and function were recorded for 1 hr after reanimation. This treatment strategy model allowed us to observe the effects of pharmacological agents that may decrease the incidence of cardiac arrhythmias and/or ischemic damage, during and after open-heart surgery.

We have developed a swine model for the target delivery of pharmacological agents within the pericardial space/fluid. Using this approach, the relative benefits of administered agents on induced atrial fibrillation, relative refractory periods and/or ischemic protection can be investigated.

To date, many pharmacological agents used to treat or prevent arrhythmias in open-heart cases create undesired systemic side effects. For example, ...

TRUE Gene Silencing: Screening of a Heptamer-type Small Guide RNA Library for Potential Cancer Therapeutic Agents

TRUE gene silencing (termed after tRNase ZL-utilizing efficacious gene silencing) is one of the RNA-directed gene silencing technologies, which utilizes an artificial small guide RNA (sgRNA) to guide tRNA 3&#8242; processing endoribonuclease, tRNase ZL, to recognize a target RNA. sgRNAs can be taken up by cells without any transfection reagents and can downregulate their target RNA levels and/or induce apoptosis in human cancer cells. We have screened an sgRNA library containing 156 heptamer-type sgRNAs for the effect on viability of human myeloma and leukemia cells, and found that 20 of them can efficiently induce apoptosis in at least one of the cancer cell lines. Here we present a protocol for screening of a heptamer-type sgRNA library for potential therapeutic drugs against blood cancers. The protocol includes how to construct the sgRNA library, how to assess the effect of each sgRNA on cell viability, and how to further evaluate the effective sgRNAs by flow cytometry. Around 2,000 hits would be expected to be obtained by screening the full-scale sgRNA library composed of 16,384 heptamers.

Here we present a protocol for screening of a heptamer-type sgRNA library for potential therapeutic drugs against blood cancers.

TRUE gene silencing (termed after tRNase ZL-utilizing efficacious gene silencing) is one of the RNA-directed gene silencing technologies, which utilizes ...

Disposable Dosators for Pulmonary Insufflation of Therapeutic Agents to Small Animals

Development of new therapeutic products requires efficacy testing in an animal model. The pulmonary route of administration can be utilized to deliver drugs locally and systemically. Evaluation of dry powder aerosols necessitates an efficient dispersion mechanism to maintain high concentrations in an exposure chamber or for direct endotracheal administration. While solutions exist to expose animals by passive inhalation to dry powder aerosols, most require masses of powder in large excess of the dose delivered. This precludes conducting early feasibility studies as insufficient drug is available at the research or early development stage to support the dose delivery requirements for conventional aerosol delivery systems. When designing an aerosol drug product, aerodynamic performance can relate directly to delivery efficiency and efficacy. Dispersion of powder into an aerosol requires energy input sufficient to overcome interparticulate forces, and particle engineering approaches can substantially improve aerosol performance. We have developed a dispersion system (dosator) which can aerosolize engineered dry powder aerosols efficiently for the purpose of direct pulmonary insufflation, dispersion into an exposure system or generation for analytical purposes.

During development of drugs for pulmonary delivery, it is necessary to evaluate pharmacokinetics and efficacy in an animal model. We present a method to build a disposable aerosol dispersion system from of-the-shelf components that can be used to administer intrapulmonary dry powder aerosol to rodents.

Development of new therapeutic products requires efficacy testing in an animal model. The pulmonary route of administration can be utilized to deliver ...

Intranasal Delivery of Therapeutic Stem Cells to Glioblastoma in a Mouse Model

The intrinsic tropism towards brain malignancies renders stem cells as promising carriers of therapeutic agents against malignant tumors. The delivery of therapeutic stem cells via the intranasal route is a recently discovered alternative strategy, with strong potential for clinical translation, due to its non-invasive nature compared to intracranial implantation or delivery via systemic routes. The lack of blood brain barrier further strengthens the therapeutic potential of stem cells undergoing intranasal brain entry. This article summarizes the essential techniques utilized in our studies and outlines the basic principles of intranasal strategy for stem cell delivery using a mouse model of intracranial glioma xenografts. We demonstrate the optimized procedures that generate consistent and reproducible results with specific predetermined experimental parameters and offer guidelines for streamlined work flow that ensure efficient execution and reliable experimental outcome. The article is designed to serve as a baseline for further experimental customization based on hypothesis, stem cell types, or tumor specifics.

Stem cells are promising therapeutic carriers to treat brain tumors due to their intrinsic tumor tropism. Non-invasive intranasal stem cell delivery bypasses the blood brain barrier and demonstrates strong potential for clinical translation. This article summarizes the basic principles of intranasal stem cell delivery in a mouse model of glioma.

The intrinsic tropism towards brain malignancies renders stem cells as promising carriers of therapeutic agents against malignant tumors. The delivery of ...

Percutaneous Contrast Echocardiography-guided Intramyocardial Injection and Cell Delivery in a Large Preclinical Model

Cell and gene therapy are exciting and promising strategies for the purpose of cardiac regeneration in the setting of heart failure with reduced ejection fraction (HFrEF). Before they can be considered for use, and implemented in humans, extensive preclinical studies are required in large animal models to evaluate the safety, efficacy, and fate of the injectate (e.g., stem cells) once delivered into the myocardium. Small rodent models offer advantages (e.g., cost effectiveness, amenability for genetic manipulation); however, given inherent limitations of these models, the findings in these rarely translate into the clinic. Conversely, large animal models such as rabbits, have advantages (e.g., similar cardiac electrophysiology compared to humans and other large animals), whilst retaining a good cost-effective balance. Here, we demonstrate how to perform a percutaneous contrast echocardiography-guided intramyocardial injection (IMI) technique, which is minimally invasive, safe, well tolerated, and very effective in the targeted delivery of injectates, including cells, into several locations within the myocardium of a rabbit model. For the implementation of this technique, we also have taken advantage of a widely available clinical echocardiography system. After putting in practice the protocol described here, a researcher with basic ultrasound knowledge will become competent in the performance of this versatile and minimally invasive technique for routine use in experiments, aimed at hypothesis testing of the capabilities of cardiac regenerative therapeutics in the rabbit model. Once competency is achieved, the whole procedure can be performed within 25 min after anaesthetizing the rabbit.

Novel therapeutic strategies in cardiac regenerative medicine require extensive and detailed studies in large preclinical animal models before they can be considered for use in humans. Here, we demonstrate a percutaneous contrast echocardiography-guided intramyocardial injection technique in rabbits, which is valuable for hypothesis testing the efficacy of such novel therapies.

Cell and gene therapy are exciting and promising strategies for the purpose of cardiac regeneration in the setting of heart failure with reduced ejection ...

Blood Collection Through Subclavian Vein Puncture in Mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

Here, we present a protocol to take blood samples from the subclavian vein of mice.

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...

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Subtitles

Delivery of Therapeutic Agents Through Intracerebroventricular (ICV) and Intravenous (IV) Injection in Mice