Funding: Supported by: NIH EY018239 (A.R.B., C.W.S., and R.E.R.), P30EY007551 (A.R.B.), and Sigma Xi Grant in Aid of Research (P.K.A.). The content is solely the responsibility of the authors and does not represent the official views of the National Institutes of Health, or Sigma Xi.

All animal protocols were approved by the Institutional Animal Care and Use Committees at the University of Houston and Baylor College of Medicine. The guidelines outlined in the Association for Research in Vision and Ophthalmology (ARVO) statement on the use of animals in vision and ophthalmic research were followed in handling and using the mice.
1. Preparation
<ol>
	<li>Preparation of fluorescein solution
	<ol>
		<li>Prepare 1% fluorescein solution by dissolving 10 mg of sodium fluorescein salt in 1 mL of sterile saline or sterile 1x phosphate buffered saline (PBS). 
		NOTE: Prepare sodium fluorescein solution on the day of use or a day before to avoid microbial contamination. When prepared a day before use, store fluorescein solution at 4 &#176;C away from light. Wrap tubes with aluminum foil to prevent photobleaching.</li>
		<li>Divide the solution into aliquots suitable for use in a single experiment. 1-1.5 &#181;L of fluorescein solution is used per mouse per time point. Use the following formula to calculate the volume of aliquot appropriate for a single experiment: 
		<img alt="Equation 1" src="/files/ftp_upload/63112/63112eq01.jpg" /> 
		NOTE: For example, if six mice are studied in a single experiment with wound size monitored at five time points, the volume of aliquot suitable for that single experiment would be: 
		<img alt="Equation 2" src="/files/ftp_upload/63112/63112eq02.jpg" /></li>
	</ol>
	</li>
	<li>Preparation of ketamine/xylazine cocktail for anesthesia of mice.
	<ol>
		<li>To prepare 10 mL of cocktail, mix 2.0 mL of ketamine (100 mg/mL) with 1.0 mL of xylazine (20 mg/mL), and add 7.0 mL of sterile PBS. Prepare ketamine/xylazine cocktail a day before or on the day of the surgery. 
		NOTE: All solutions should be used at room temperature unless stated otherwise.</li>
	</ol>
	</li>
</ol>
2. Anesthesia
<ol>
	<li>Weigh the mouse (8-12 weeks old C57BL/6 wildtype mice) to determine the appropriate amount of anesthetic to administer. Use the two-handed mouse restraint technique to restrain and handle mice for the injection of the anesthetic18. Administer ketamine/xylazine cocktail intraperitoneally (i.p.) at a final concentration of 80 mg/kg of ketamine and 8 mg/kg of xylazine.</li>
	<li>Wait until complete anesthesia is achieved before performing corneal wounding on the mouse. Evaluate the depth of anesthesia by assessing the pedal reflex after toe pinch. When adequate anesthesia is achieved, the mouse should not move upon toe pinch. 
	&#8203;NOTE: Because mice quickly lose body heat during anesthesia, it is important to provide a source of warmth for mice to prevent hypothermia. Place mice on a heat source (heating pad) during anesthesia and recovery stages.</li>
</ol>
3. Creation of corneal wound
<ol>
	<li>Wound the right or left eye only. Maintain consistency with the eye (i.e., left or right) that is wounded when moving from mouse to mouse. 
	NOTE: Because abrasions damage corneal nerves and reduce acuity, wounding both eyes can cause significant discomfort and impairment. Since analgesics have the potential to suppress inflammatory responses, their use may be a confounder in certain experiments aimed at understanding corneal inflammation. Avoiding analgesics in corneal wound experiments was approved by our Institutional Animal Care and Use Committee (IACUC).</li>
	<li>To create the epithelial corneal wound
	<ol>
		<li>Under a dissecting microscope, use the 2 mm diameter trephine (see Figure 1) to demarcate the center of the cornea, keeping the eye wide open using the thumb and index finger to hold the eyelids. Gently twirl the trephine to make an impression on the corneal epithelium. 
		NOTE: Care must be taken to not apply excessive pressure when using the trephine as this can result in corneal perforation. Also, care must be taken to position the trephine centrally. The pupils can be used as a landmark to locate the center of the cornea.</li>
		<li>Under a dissecting microscope, hold the blunt golf club spud (see Figure 1) at approximately 45&#176; from the surface of the cornea within the area demarcated with the trephine. Carefully and continuously scrape the epithelium within the demarcated area with the spud to debride the epithelium. 
		&#8203;NOTE: Do not apply excessive force in debridement as that can also cause corneal perforation. The eyes of mice can dry up during the wounding process, making debridement difficult. In such a case, apply sterile PBS to the ocular surface to maintain optimal hydration.</li>
	</ol>
	</li>
</ol>
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63112/63112fig01.jpg" /> 
Figure 1: 2 mm trephine and blunt golf club spud. The trephine is used to demarcate a circular region at the cornea center, and the golf club spud is used to remove the epithelium within the demarcated region. <a href="https://www.jove.com/files/ftp_upload/63112/63112fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
4. Monitoring of wound closure and re-epithelialization
<ol>
	<li>Pipette 1-1.5 &#181;L of 1% fluorescein solution onto the wounded surface and image cornea using a digital microscope with a blue light source.</li>
	<li>Acquire images within the first minute of fluorescein solution addition to avoid spreading to surrounding epithelium leading to overestimation of wound size. Wounded corneas are imaged at specific times (i.e., 0 h, 12 h, 18 h, 24 h, and 30 h) after wounding. 
	NOTE: At all time points, imaging is performed under anesthesia; ketamine/xylazine is used at the time of wounding while isoflurane is used at subsequent timepoints. Mice are housed individually in separate cages for the duration of wound closure monitoring. When housed together, mice tend to lick littermate&#39;s eyes, a behavior which has been shown to affect wound healing in different tissues19,20.</li>
	<li>Analyze captured images,&#160;tracing&#160;wound area&#160;using an image analysis software. The wound area for each time point is expressed as a percentage of the original wound area at 0 h.</li>
</ol>
5. Immunofluorescence imaging and analysis
<ol>
	<li>Euthanize mice by an IACUC-approved method (in this case, carbon dioxide overdose followed by cervical dislocation) at desired time points after wounding.</li>
	<li>Harvest eyeballs by gently pressing on the lateral canthus to displace the eyeball using&#160;iris curved scissor. Guide the scissors behind the eyeball to firmly grasp the optic nerve, and then cut the nerve, which allows the eyeball to be removed.</li>
	<li>Fix each eyeball in 1 mL of 1x PBS containing 2% paraformaldehyde for 1 h at room temperature, and then wash three times in 1 mL of 1x PBS for 5 min each.</li>
	<li>Under a dissecting microscope, use a surgical blade to make an incision in the sclera, about 500 &#181;m distal to the limbus, and then cut through the globe. Using forceps, gently remove the iris matter from the cornea, and then carefully trim the scleral tissue away, making sure to leave the limbus intact.</li>
	<li>Make four partial radial cuts, each approximately 1 mm in length, which extend from the peripheral cornea and stop short of the center to allow the cornea to flatten.</li>
	<li>Permeabilize and block corneas in 1 mL of 2% bovine serum albumin (BSA) and 0.01% TritonX -100 in 1x PBS for 15 min followed by blocking in 2% BSA in 1x PBS for an additional 45 min at room temperature.</li>
	<li>Incubate corneas overnight at 4 &#176;C in a cocktail of directly labeled unique fluorochrome conjugated antibodies prepared in 1x PBS containing 2% BSA. 
	NOTE: Antibodies are targeted to label specific cells and tissues of interest. For example, endothelium, neutrophils, and platelets are labeled with anti-CD3121,22, anti-Ly-6G23,24, and anti-CD4125,26 antibodies, respectively. 4&#39;,6-diamidino-2-phenylindole (DAPI) is added to the antibody cocktail to visualize nuclei.</li>
	<li>After incubation, wash corneas three times in 1x PBS for 15 min each.</li>
	<li>Mount corneas on a microscope slide in a drop of anti-fade fluorescence mounting medium, cover with a coverslip, and image with the desired magnification (4x to 100x objective) using a fluorescence light microscope. Take full-thickness images of the cornea across different regions as illustrated in Figure 2A. 
	NOTE: The pattern of microscopic analysis illustrated in Figure 2A is used for analyzing specific regional changes in inflammation and cell division. Both DAPI and Ly-6G staining are used to identify the extravascular neutrophils. With DAPI staining, spherical neutrophils have a distinct horseshoe or donut shaped nucleus (Figure 2B).</li>
</ol>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63112/63112fig02.jpg" /> 
Figure 2: Corneal imaging strategy and neutrophil infiltration after central abrasion. (A) Schematic representation of a cornea wholemount showing nine microscopic fields across the diameter of the cornea. The gray area represents the original wound area. The width of each region is 500 &#181;m. (B) Note the distinct horseshoe or donut shape of neutrophil nuclei with DAPI staining. <a href="https://www.jove.com/files/ftp_upload/63112/63112fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

The authors have nothing to disclose.

The purpose of this methods paper was to describe a protocol for creating a central corneal epithelial abrasion wound in the mouse using a trephine and a blunt golf club spud. This murine model has been used to study corneal inflammation and its contribution to wound healing. This type of model can be used to study corneal wound healing mechanisms under normal physiological conditions and in pathologies17,28,29,<sup c...

The cornea is the transparent anterior one-third of the eye. The cornea serves several functions including protecting the inner structures of the eye and forming a structural barrier that protects the eye against infections1. More importantly, the cornea is critical for vision, providing about two-thirds of the refractive power of the eye2,3. Crucial to the role of the cornea in vision is its transparency. However, due to its outward position, the cornea is exposed to a wide variety of injuries on a day-to-day basis that can lead to disruption of its barrier function, loss of transparency, and eventual blindness. Loss of corneal transparency is a leading cause of visual impairment worldwide4,5. Corneal abrasions are a common reason for visits to the emergency room (ER), accounting for half of the eye-related cases presented at the ER6. Over 1 million individuals are estimated to suffer from eye-related injuries annually in the United States7. Efficient corneal wound healing in response to these injuries is pivotal for maintaining corneal homeostasis and preservation of its transparency and refractive capabilities. In events of compromised corneal wound healing, the cornea becomes vulnerable to infections, ulcerations, and scarring8,9. Also, the increasing popularity of refractive surgeries places a unique traumatic challenge on the cornea10. Given the fundamental importance of corneal wound healing to the preservation of corneal transparency and vision, a better understanding of the normal corneal wound healing process is a prerequisite to understanding impaired corneal wound healing associated with infection and disease.
To that end, several animal models of corneal wound healing have been developed11,12,13,14,15. Murine models of corneal wound healing have proven useful in furthering our understanding of the corneal wound healing mechanisms operating under normal physiological conditions. Different types of corneal wounds have been employed in studying corneal wound healing, each suitable for investigating different aspects of the wound healing process. The commonest types of wound models used in corneal wound healing studies are the mechanical and chemical wound models. Chemical corneal wounds, mostly involving the creation of alkaline burns on the cornea, are useful for studying corneal ulcers, opacification, and neovascularization13. Mechanical corneal wounds involve debridement (abrasion) wounds and keratectomy wounds14,15,16. An intact or breached corneal epithelial basement membrane defines debridement and keratectomy wounds, respectively. In debridement wounds, the epithelial basement membrane remains intact, while in keratectomy wounds, the basement membrane is breached with penetration mostly into the anterior stroma. Debridement wounds are most useful for studying re-epithelialization, epithelial cell proliferation, immune response, and nerve regeneration following corneal wounding. Keratectomy wounds, on the other hand, are most useful for studying corneal scarring14,15.
Here, a protocol for creating a central corneal epithelial abrasion wound in the mouse using a trephine and a blunt golf club spud is described. This simple corneal wound healing model is highly reproducible and well-published and is now being used to evaluate compromised corneal wound healing in the context of disease17.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Anti-CD31 antibody</td>
			<td>BD Bioscience, Pharmingen</td>
			<td>550274</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-CD41 antibody</td>
			<td>BD Bioscience, Pharmingen</td>
			<td>553847</td>
			<td></td>
		</tr>
		<tr>
			<td>Anti-Ly6G antibody</td>
			<td>BD Bioscience, Pharmingen</td>
			<td>551459</td>
			<td></td>
		</tr>
		<tr>
			<td>Bovine serum albumin (BSA)</td>
			<td>ThermoFisher scientific</td>
			<td>B14</td>
			<td></td>
		</tr>
		<tr>
			<td>C57BL/6 mice</td>
			<td>Jackson Laboratories</td>
			<td>664</td>
			<td></td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma Aldrich</td>
			<td>D8417</td>
			<td></td>
		</tr>
		<tr>
			<td>DeltaVision wide-field deconvolution fluorescence microscope</td>
			<td>GE Life Sciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dissecting microscope</td>
			<td>Leica microsystems</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Electronic Toploading Balances (Weighing scale)</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>ThermoFisher scientific</td>
			<td>T038181000CS</td>
			<td></td>
		</tr>
		<tr>
			<td>Golf-club spud</td>
			<td>Stephens instruments</td>
			<td>S2-1135</td>
			<td></td>
		</tr>
		<tr>
			<td>Iris curve scissors</td>
			<td>Fisher Scientific</td>
			<td>31212</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Patterson veterinary</td>
			<td>07-893-1389</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine</td>
			<td>Patterson veterinary</td>
			<td>07-890-8598</td>
			<td></td>
		</tr>
		<tr>
			<td>Phospate buffered saline (PBS)</td>
			<td>ThermoFisher scientific</td>
			<td>AM9624</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium fluorescein salt</td>
			<td>Sigma Aldrich</td>
			<td>46970</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical blade (scapel blade)</td>
			<td>Fine Science tools</td>
			<td>10022-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Trephine</td>
			<td>Integra Miltex</td>
			<td>33-31</td>
			<td></td>
		</tr>
		<tr>
			<td>TritonX -100</td>
			<td>Fisher Scientific</td>
			<td>50-295-34</td>
			<td></td>
		</tr>
		<tr>
			<td>Forcep</td>
			<td>Fine Science tools</td>
			<td>11923-13</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Patterson veterinary</td>
			<td>07-808-1947</td>
			<td></td>
		</tr>
	</tbody>
</table>

an epithelial abrasion model for studying corneal wound healing

The cornea is critical for vision, accounting for about two-thirds of the refractive power of the eye. Crucial to the role of the cornea in vision is its transparency. However, due to its external position, the cornea is highly susceptible to a wide variety of injuries that can lead to the loss of corneal transparency and eventual blindness. Efficient corneal wound healing in response to these injuries is pivotal for maintaining corneal homeostasis and preservation of corneal transparency and refractive capabilities. In events of compromised corneal wound healing, the cornea becomes vulnerable to infections, ulcerations, and scarring. Given the fundamental importance of corneal wound healing to the preservation of corneal transparency and vision, a better understanding of the normal corneal wound healing process is a prerequisite to understanding impaired corneal wound healing associated with infection and disease. Toward this goal, murine models of corneal wounding have proven useful in furthering our understanding of the corneal wound healing mechanisms operating under normal physiological conditions. Here, a protocol for creating a central corneal epithelial abrasion in mouse using a trephine and a blunt golf club spud is described. In this model, a 2 mm diameter circular trephine, centered over the cornea, is used to demarcate the wound area. The golf club spud is used with care to debride the epithelium and create a circular wound without damaging the corneal epithelial basement membrane. The resulting inflammatory response proceeds as a well-characterized cascade of cellular and molecular events that are critical for efficient wound healing. This simple corneal wound healing model is highly reproducible and well-published and is now being used to evaluate compromised corneal wound healing in the context of disease.

Figure 3 shows a transmission electron micrograph of a corneal wound created with the blunt golf club spud, demonstrating that the epithelial&#160;basement membrane is indeed intact after injury.
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63112/63112fig03.jpg" /> 
Figure 3: Epithelial basement membrane remains intact after corneal abrasion. Transmission electron mi...

Watch this Scientific Journal Video about An Epithelial Abrasion Model for Studying Corneal Wound Healing at JoVE.com

An Epithelial Abrasion Model for Studying Corneal Wound Healing

Here, a protocol for creating a central corneal epithelial abrasion wound in the mouse using a trephine and a blunt golf club spud is described. This corneal wound healing model is highly reproducible and is now being used to evaluate compromised corneal wound healing in the context of diseases.

The cornea is critical for vision, accounting for about two-thirds of the refractive power of the eye. Crucial to the role of the cornea in vision is its ...

an-epithelial-abrasion-model-for-studying-corneal-wound-healing

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3.1K Views.  University of Houston. Here, a protocol for creating a central corneal epithelial abrasion wound in the mouse using a trephine and a blunt golf club spud is described. This corneal wound healing model is highly reproducible and is now being used to evaluate compromised corneal wound healing in the context of diseases.

Video: An Epithelial Abrasion Model for Studying Corneal Wound Healing

A Simplified Technique for Producing an Ischemic Wound Model

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work well in non-ischemic wounds may not work in human diabetic wounds because vasculopathy is one major factor that hinders healing of these wounds. We published an article in 2007 describing a rabbit ear ischemic wound model created by a minimally invasive surgical technique. Since then, we have further simplified the procedure for easier operation. On one ear, three small skin incisions were made on the vascular pedicles, 1-2 cm from the ear base. The central artery was ligated and cut along with the nerve. The whole cranial bundle was cut and ligated, leaving only the caudal branch intact. A circumferential subcutaneous tunnel was made through the incisions, to cut subcutaneous tissues, muscles, nerves, and small vessels. The other ear was used as a non-ischemic control. Four wounds were made on the ventral side of each ear. This technique produces 4 ischemic wounds and 4 non-ischemic wounds in one animal for paired comparisons. After surgery, the ischemic ear was cool and cyanotic, and showed reduced movement and a lack of pulse in the ear artery. Skin temperature of the ischemic ear was 1-10 &deg;C lower than that on the normal ear and this difference was maintained for more than one month. Ear tissue high-energy phosphate contents were lower in the ischemic ear than the control ear. Wound healing times were longer in the ischemic ear than in the non-ischemic ear when the same treatment was used. The technique has now been used on more than 80 rabbits in which 23 were diabetic (diabetes time ranging from 2 weeks to 2 years). No single rabbit has developed any surgical complications such as bleeding, infection, or rupture in the skin incisions. The model has many advantages, such as little skin disruption, longer ischemic time, and higher success rate, when compared to many other models. It can be safely used in animals with reduced resistance, and can also be modified to meet different testing requirements.

We have developed a minimally invasive technique to create a rabbit ischemic ear wound model by dividing the central artery and nerve and the cranial neurovascular bundle. A subcutaneous tunnel then cuts all subcutaneous tissues. This procedure causes minimal skin disruption and can be safely used in diabetic animals.

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work ...

Murine Model of Wound Healing

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. Impaired wound healing, which occurs in diabetic patients for example, can lead to severe unfavorable outcomes such as amputation. There is, therefore, an increasing impetus to develop novel agents that promote wound repair. The testing of these has been limited to large animal models such as swine, which are often impractical. Mice represent the ideal preclinical model, as they are economical and amenable to genetic manipulation, which allows for mechanistic investigation. However, wound healing in a mouse is fundamentally different to that of humans as it primarily occurs via contraction. Our murine model overcomes this by incorporating a splint around the wound. By splinting the wound, the repair process is then dependent on epithelialization, cellular proliferation and angiogenesis, which closely mirror the biological processes of human wound healing. Whilst requiring consistency and care, this murine model does not involve complicated surgical techniques and allows for the robust testing of promising agents that may, for example, promote angiogenesis or inhibit inflammation. Furthermore, each mouse acts as its own control as two wounds are prepared, enabling the application of both the test compound and the vehicle control on the same animal. In conclusion, we demonstrate a practical, easy-to-learn, and robust model of wound healing, which is comparable to that of humans.

A murine model of cutaneous wound healing that can be used to assess therapeutic compounds in physiological and pathophysiological settings.

Wound healing and repair are the most complex biological processes that occur in human life. After injury, multiple biological pathways become activated. ...

Multimodal Quantitative Phase Imaging with Digital Holographic Microscopy Accurately Assesses Intestinal Inflammation and Epithelial Wound Healing

The incidence of inflammatory bowel disease, i.e., Crohn&#39;s disease and Ulcerative colitis, has significantly increased over the last decade. The etiology of IBD remains unknown and current therapeutic strategies are based on the unspecific suppression of the immune system. The development of treatments that specifically target intestinal inflammation and epithelial wound healing could significantly improve management of IBD, however this requires accurate detection of inflammatory changes. Currently, potential drug candidates are usually evaluated using animal models in vivo or with cell culture based techniques in vitro. Histological examination usually requires the cells or tissues of interest to be stained, which may alter the sample characteristics and furthermore, the interpretation of findings can vary by investigator expertise. Digital holographic microscopy (DHM), based on the detection of optical path length delay, allows stain-free quantitative phase contrast imaging. This allows the results to be directly correlated with absolute biophysical parameters. We demonstrate how measurement of changes in tissue density with DHM, based on refractive index measurement, can quantify inflammatory alterations, without staining, in different layers of colonic tissue specimens from mice and humans with colitis. Additionally, we demonstrate continuous multimodal label-free monitoring of epithelial wound healing in vitro, possible using DHM through the simple automated determination of the wounded area and simultaneous determination of morphological parameters such as dry mass and layer thickness of migrating cells. In conclusion, DHM represents a valuable, novel and quantitative tool for the assessment of intestinal inflammation with absolute values for parameters possible, simplified quantification of epithelial wound healing in vitro and therefore has high potential for translational diagnostic use.

Accurate assessment of anti-inflammatory effects is of utmost importance for the evaluation of potential new drugs for the treatment of inflammatory bowel disease. Digital holographic microscopy provides assessment of inflammation in murine and human colonic tissue samples as well as automated multimodal evaluation of epithelial wound healing in vitro.

The incidence of inflammatory bowel disease, i.e., Crohn&#39;s disease and Ulcerative colitis, has significantly increased over the last decade. The ...

Creation and Transplantation of an Adipose-derived Stem Cell (ASC) Sheet in a Diabetic Wound-healing Model

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients with impeded blood flow or with large wounds might be prolonged. Cell-based therapies have appeared as a new technique for the treatment of diabetic ulcers, and cell-sheet engineering has improved the efficacy of cell transplantation. A number of reports have suggested that adipose-derived stem cells (ASCs), a type of mesenchymal stromal cell (MSC), exhibit therapeutic potential due to their relative abundance in adipose tissue and their accessibility for collection when compared to MSCs from other tissues. Therefore, ASCs appear to be a good source of stem cells for therapeutic use. In this study, ASC sheets from the epididymal adipose fat of normal Lewis rats were successfully created using temperature-responsive culture dishes and normal culture medium containing ascorbic acid. The ASC sheets were transplanted into Zucker diabetic fatty (ZDF) rats, a rat model of type 2 diabetes and obesity, that exhibit diminished wound healing. A wound was created on the posterior cranial surface, ASC sheets were transplanted into the wound, and a bilayer artificial skin was used to cover the sheets. ZDF rats that received ASC sheets had better wound healing than ZDF rats without the transplantation of ASC sheets. This approach was limited because ASC sheets are sensitive to dry conditions, requiring the maintenance of a moist wound environment. Therefore, artificial skin was used to cover the ASC sheet to prevent drying. The allogenic transplantation of ASC sheets in combination with artificial skin might also be applicable to other intractable ulcers or burns, such as those observed with peripheral arterial disease and collagen disease, and might be administered to patients who are undernourished or are using steroids. Thus, this treatment might be the first step towards improving the therapeutic options for diabetic wound healing.

Creation and Transplantation of an Adipose-derived Stem Cell ASC Sheet in a Diabetic Wound-healing Model

Adipose-derived stem cells (ASCs) are easily isolated and harvested from the fat of normal rats. ASC sheets can be created using cell-sheet engineering and can be transplanted into Zucker diabetic fatty rats exhibiting full-thickness skin defects with exposed bone and then covered with a bilayer of artificial skin.

Artificial skin has achieved considerable therapeutic results in clinical practice. However, artificial skin treatments for wounds in diabetic patients ...

Development of a Direct Pulp-capping Model for the Evaluation of Pulpal Wound Healing and Reparative Dentin Formation in Mice

Dental pulp is a vital organ of a tooth fully protected by enamel and dentin. When the pulp is exposed due to cariogenic or iatrogenic injuries, it is often capped with biocompatible materials in order to expedite pulpal wound healing. The ultimate goal is to regenerate reparative dentin, a physical barrier that functions as a "biological seal" and protects the underlying pulp tissue. Although this direct pulp-capping procedure has long been used in dentistry, the underlying molecular mechanism of pulpal wound healing and reparative dentin formation is still poorly understood. To induce reparative dentin, pulp capping has been performed experimentally in large animals, but less so in mice, presumably due to their small sizes and the ensuing technical difficulties. Here, we present a detailed, step-by-step method of performing a pulp-capping procedure in mice, including the preparation of a Class-I-like cavity, the placement of pulp-capping materials, and the restoration procedure using dental composite. Our pulp-capping mouse model will be instrumental in investigating the fundamental molecular mechanisms of pulpal wound healing in the context of reparative dentin in vivo by enabling the use of transgenic or knockout mice that are widely available in the research community.

We describe a step-by-step method of performing direct pulp capping on mice teeth for the evaluation of pulpal wound healing and reparative dentin formation in vivo.

Dental pulp is a vital organ of a tooth fully protected by enamel and dentin. When the pulp is exposed due to cariogenic or iatrogenic injuries, it is ...

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During In Vitro Wound Healing

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated experimental procedures, while potentially lacking in precision. In vitro culture of epithelial cell lines provides a suitable platform for researching the cell migratory behavior in wound healing and the impact of treatments on these cells. The physiology of epithelial cells is often studied in non-confluent conditions; however, this approach may not resemble natural wound healing conditions. Disrupting the epithelium integrity by mechanical means generates a realistic model, but may impede the application of molecular techniques. Consequently, microscopy based techniques are optimal for studying epithelial cell migration in vitro. Here we detail two specific methods, the artificial wound scratch assay and the artificial migration front assay, that can obtain quantitative and qualitative data, respectively, on the migratory performance of epithelial cells.

Microscopy Based Methods for the Assessment of Epithelial Cell Migration During  In Vitro Wound Healing

This manuscript describes how incision-like lesions made on cultured epithelial cell monolayers conveniently model wound healing in vitro, allowing for imaging by confocal or laser scanning microscopy, and which can provide high-quality quantitative and qualitative data for studying both cell behavior and the mechanisms involved in migration.

Cell migration is a mandatory aspect for wound healing. Creating artificial wounds on research animal models often results in costly and complicated ...

Corneal Epithelial Abrasion with Ocular Burr As a Model for Cornea Wound Healing

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to injury. In fact, the most common type of eye injury found in clinic is a corneal abrasion. Here, we utilize an ocular burr to induce an abrasion resulting in removal of the corneal epithelium in vivo on anesthetized mice. This method allows for targeted and reproducible epithelial disruption, leaving other areas intact. In addition, we describe the visualization of the abraded epithelium with fluorescein staining and provide concrete advice on how to visualize the abraded cornea. Then, we follow the timeline of wound healing 0, 18, and 72 h after abrasion, until the wound is re-epithelialized. The epithelial abrasion model of corneal injury is ideal for studies on epithelial cell proliferation, migration and re-epithelialization of the corneal layers. However, this method is not optimal to study stromal activation during wound healing, because the ocular burr does not penetrate to the stromal cell layers. This method is also suitable for clinical applications, for example, pre-clinical test of drug effectiveness.

This protocol describes a method to inflict an abrasion to the ocular surface of the mouse, and to follow the wound healing process thereafter. The protocol takes advantage of an ocular burr to partially remove the surface epithelium of the eye in anaesthetized mice.

The murine cornea provides an excellent model to study wound healing. The cornea is the outermost layer of the eye, and thus is the first defense to ...

Ex Vivo Corneal Organ Culture Model for Wound Healing Studies

The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two dimensional (2D) and three dimensional (3D) culture has generated a wealth of information not only about corneal biology but also about wound healing, myofibroblast biology, and scarring in general. The goal of the protocol is an assay system for quantifying myofibroblast development, which characterizes scarring. We demonstrate a corneal organ culture ex vivo model using pig eyes. In this anterior keratectomy wound, corneas still in the globe are wounded with a circular blade called a trephine. A plug of approximately 1/3 of the anterior cornea is removed including the epithelium, the basement membrane, and the anterior part of the stroma. After wounding, corneas are cut from the globe, mounted on a collagen/agar base, and cultured for two weeks in supplemented-serum free medium with stabilized vitamin C to augment cell proliferation and extracellular matrix secretion by resident fibroblasts. Activation of myofibroblasts in the anterior stroma is evident in the healed cornea. This model can be used to assay wound closure, the development of myofibroblasts and fibrotic markers, and for toxicology studies. In addition, the effects of small molecule inhibitors as well as lipid-mediated siRNA transfection for gene knockdown can be tested in this system.

A protocol for an ex vivo corneal organ culture model useful for wound healing studies is described. This model system can be used to assess the effects of agents to promote regenerative healing or drug toxicity in an organized 3D multicellular environment.

The cornea has been used extensively as a model system to study wound healing. The ability to generate and utilize primary mammalian cells in two ...

Targeting Gray Rami Communicantes in Selective Chemical Lumbar Sympathectomy

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the lower extremities, hyperhidrosis, etc. It is commonly practiced to position the puncture needle tip in front of the anterior fascia of the psoas major muscle and inject the inactivating agent around the sympathetic trunk, which is defined as conventional CLS. Although relatively rare, ureteropelvic damage is the most frequently reported complication of conventional CLS and can cause serious harm to patients. We found that injecting the inactivating agent behind the anterior fascia, which only targets gray rami communicantes, helped achieve therapeutic efficacy in&#160;vasodilation, sweat reduction, and pain relief comparable to conventional CLS, and serious complications were largely reduced. We define this procedure as selective CLS. Here, we present a protocol of selective CLS. The precise needle tract and accurate evaluation of the spreading of the contrast agent are critical to ensure that the drug is injected behind the anterior fascia of the psoas major muscle. The needle tip is at approximately one-third the dividing line of the vertebral body in the lateral view of a lumbar X-ray. The contrast is mainly confined around the needle tip and spreads outward and downward along the psoas muscle fibers. In this way, the anterior fascia provides a natural barrier for the ureteropelvic area, and the psoas major muscle provides a natural barrier for the lumbar nerve root. There are several highlights of this article, including 1) a detailed description of the selective CLS procedures, 2) an explanation of the anatomical basis for the implementation of selective CLS, and 3) an explanation of the differences between selective and conventional CLS.

We present a protocol for selective chemical lumbar sympathectomy (CLS), which inactivates only gray rami communicantes and not the sympathetic trunk. Selective CLS can help achieve therapeutic efficacy in vasodilation, sweat reduction, and pain relief that are comparable to conventional CLS, and serious complications, particularly ureteropelvic damages, can be reduced.

Chemical lumbar sympathectomy (CLS) is a commonly used, minimally invasive procedure for the treatment of conditions including ischemic diseases of the ...

A Porcine Corneal Endothelial Organ Culture Model Using Split Corneal Buttons

Experimental research on corneal endothelial cells is associated with several difficulties. Human donor corneas are scarce and rarely available for experimental investigations as they are normally needed for transplantation. Endothelial cell cultures often do not translate well to in vivo situations. Due to the biostructural characteristics of non-human corneas, stromal swelling during cultivation induces substantial corneal endothelial cell loss, which makes it difficult to perform cultivation for an extended period of time. Deswelling agents such as dextran are used to counteract this response. However, they also cause significant endothelial cell loss. Therefore, an ex vivo organ culture model not requiring deswelling agents was established. Pig eyes from a local slaughterhouse were used to prepare split corneal buttons. After partial corneal trephination, the outer layers of the cornea (epithelium, bowman layer, parts of the stroma) were removed. This significantly reduces corneal endothelial cell loss induced by massive stromal swelling and Descemet&#39;s membrane folding throughout longer cultivation periods and improves general preservation of the endothelial cell layer. Subsequent complete corneal trephination was followed by the removal of the split corneal button from the remaining eye bulb and cultivation. Endothelial cell density was assessed at follow-up times of up to 15 days after preparation (i.e., days 1, 8, 15) using light microscopy. The preparation technique used allows a better preservation of the endothelial cell layer enabled by less stromal tissue swelling, which results in slow and linear decline rates in split corneal buttons comparable to human donor corneas. As this standardized organo-typically cultivated research model for the first time allows a stable cultivation for at least two weeks, it is a valuable alternative to human donor corneas for future investigations of various external factors with regards to their effects on the corneal endothelium.

Here, a step-by-step protocol for the preparation and cultivation of porcine split corneal buttons is presented. As this organo-typically cultivated organ culture model shows cell death rates within 15 days, comparable to human donor corneas, it represents the first model allowing long-term cultivation of non-human corneas without adding toxic dextran.

Experimental research on corneal endothelial cells is associated with several difficulties. Human donor corneas are scarce and rarely available for ...