Name: 2-methacryloyloxyethyl phosphorylcholine polymer treatment of complete dentures to inhibit denture plaque deposition
Uploaded: 2016-12-26T15:00:00
Description: Watch this Scientific Journal Video about 2-Methacryloyloxyethyl Phosphorylcholine Polymer Treatment of Complete Dentures to Inhibit Denture Plaque Deposition at JoVE.com

The authors wish to thank all of the participants, dentists, and assistants for their participation in this study. We sincerely thank Professor Hirotaka Kuwata and Assistant Professor Hirobumi Morisaki, Department of Oral Microbiology and Immunology, Showa University School of Dentistry, for their support.

1. Preparation of PMBPAz Solution (Figure 1)
<ol>
	<li>Synthesize MPC following a previously reported industrial procedure15.</li>
	<li>Synthesize the photoreactive MPC polymer PMBPAz using conventional radical polymerization of MPC, BMA, and MPAz in ethanol, as previously described14. 
	NOTE: PMBPAz should contain 60%, 30%, and 10% (mol %) of the aforementioned monomer units, respectively. Refrigerate the PMBPAz dissolved in ethanol to prepare a 0.5 wt% solution before use.</li>
	<li>Before ...

<ol>
	<li>Watando, 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=Daily+oral+care+and+cough+reflex+sensitivity+in+elderly+nursing+home+patients.">Daily oral care and cough reflex sensitivity in elderly nursing home patients.</a> Chest. 126, 1066-1070 (2004).</li><li>Bassim, C. W., Gibson, G., Ward, T., Paphides, B. M., DeNucci, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modification+of+the+risk+of+mortality+from+pneumonia+with+oral+hygiene+care.">Modification of the risk of mortality from pneumonia with oral hygiene care.</a> J. Am. Geriatr. Soc. 56, 1601-1607 (2008).</li><li>Ishikawa, A., Yoneyama, T., Hirota, K., Miyake, Y., Miyatake, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Professional+oral+health+care+reduces+the+number+of+oropharyngeal+bacteria.">Professional oral health care reduces the number of oropharyngeal bacteria.</a> J. Dent. Res. 87, 594-598 (2008).</li><li>Hosokawa, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prosthodontic+interventions+for+special-needs+patients.">Prosthodontic interventions for special-needs patients.</a> J Prosthodont Res. 58, 69-70 (2014).</li><li>Parvizi, A., Lindquist, T., Schneider, R., Williamson, D., Boyer, D., Dawson, D. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+dimensional+accuracy+of+injection-molded+denture+base+materials+to+that+of+conventional+pressure-pack+acrylic+resin.">Comparison of the dimensional accuracy of injection-molded denture base materials to that of conventional pressure-pack acrylic resin.</a> J. Prosthodont. 13, 83-89 (2004).</li><li>Ishihara, K., Ueda, T., Nakabayashi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+phospholipid+polylmers+and+their+properties+as+polymer+hydrogel+membranes.">Preparation of phospholipid polylmers and their properties as polymer hydrogel membranes.</a> Polym. J. 22, 355-360 (1990).</li><li>Ishihara, K., Aragaki, R., Ueda, T., Watenabe, A., Nakabayashi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduced+thrombogenicity+of+polymers+having+phospholipid+polar+groups.">Reduced thrombogenicity of polymers having phospholipid polar groups.</a> J. Biomed. Mater. Res. 24 (8), 1069-1077 (1990).</li><li>Ishihara, K., Ziats, N. P., Tierney, B. P., Nakabayashi, N., Anderson, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+adsorption+from+human+plasma+is+reduced+on+phospholipid+polymers.">Protein adsorption from human plasma is reduced on phospholipid polymers.</a> J. Biomed. Mater. Res. 25 (11), 1397-1407 (1991).</li><li>Ishihara, K., Nomura, H., Mihara, T., Kurita, K., Iwasaki, Y., Nakabayashi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Why+do+phospholipid+polymers+reduce+protein+adsorption?.">Why do phospholipid polymers reduce protein adsorption?.</a> J. Biomed. Mater. Res. 39 (2), 323-330 (1998).</li><li>Ishihara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioinspired+phospholipid+polymer+biomaterials+for+making+high+performance+artificial+organs.">Bioinspired phospholipid polymer biomaterials for making high performance artificial organs.</a> Sci. Technol. Adv. Mater. 1 (3), 131-138 (2000).</li><li>Iwasaki, Y., Ishihara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+membrane-inspired+phospholipid+polymers+for+developing+medical+devices+with+excellent+biointerfaces.">Cell membrane-inspired phospholipid polymers for developing medical devices with excellent biointerfaces.</a> Sci. Technol. Adv. Mater. 13 (6), 064101 (10pp) (2012).</li><li>Zhang, N., Chen, C., Melo, M. 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=A+novel+protein-repellent+dental+composite+containing+2-methacryloyloxyethyl+phosphorylcholine.">A novel protein-repellent dental composite containing 2-methacryloyloxyethyl phosphorylcholine.</a> Int J Oral Sci. 7, 103-109 (2015).</li><li>Hirota, K., Yumoto, H., Miyamoto, K., 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=MPC-polymer+reduces+adherence+and+biofilm+formation+by+oral+bacteria.">MPC-polymer reduces adherence and biofilm formation by oral bacteria.</a> J Dent Res. 90, 900-905 (2011).</li><li>Fukazawa, K., Ishihara, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+photoreactive+phospholipid+polymers+for+use+in+versatile+surface+modification+of+various+materials+to+obtain+extreme+wettability.">Synthesis of photoreactive phospholipid polymers for use in versatile surface modification of various materials to obtain extreme wettability.</a> ACS Appl. Mater. Interfaces. 5 (15), 6832-6836 (2013).</li><li>Ishihara, K., Ueda, T., Nakabayashi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+phospholipid+polymers+and+their+properties+as+polymer+hydrogel+membranes.">Preparation of phospholipid polymers and their properties as polymer hydrogel membranes.</a> Polym. J. 22 (5), 355-360 (1990).</li><li>Coulthwaite, L., Verran, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+in+vivo+denture+plaque+assessment+methods.">Evaluation of in vivo denture plaque assessment methods.</a> Br Dent J. 207 (E12), 282-283 (2009).</li><li>He, D., Susanto, H., Ulbricht, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photo-irradiation+for+preparation,+modification+and+stimulation+of+polymeric+membranes.">Photo-irradiation for preparation, modification and stimulation of polymeric membranes.</a> Prog Polym Sci. 34, 62-98 (2009).</li><li>Nakayama, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+macromolecular+architectural+designs+using+photo-graft+copolymerization+based+on+photochemistry+of+benzyl+N,N-diethyldithiocarbamate.">Surface macromolecular architectural designs using photo-graft copolymerization based on photochemistry of benzyl N,N-diethyldithiocarbamate.</a> Macromolecules. 29, 8622-8630 (1996).</li><li>Takahashi, N., Iwasa, F., Inoue, Y., Morisaki, H., Ishihara, K., Baba, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+the+durability+and+antiadhesive+action+of+2-methacryloyloxyethyl+phosphorylcholine+grafting+on+an+acrylic+resin+denture+base.">Evaluation of the durability and antiadhesive action of 2-methacryloyloxyethyl phosphorylcholine grafting on an acrylic resin denture base.</a> J. Prosthet. Dent. 112 (2), 194-203 (2014).</li></ol>

Mechanism of the PMBPAz Coating
It is challenging to bind MPC polymers to a PMMA surface in a simple and stable manner. Here, we used a new photoreactive monomer bearing a phenylazide group, MPAz, which polymerizes with other monomers through a conventional free-radical polymerization procedure, resulting in a polymer with phenylazide side chains. The phenylazide groups are decomposed by UV irradiation to form nitrene groups, which are highly reactive radical groups that can covalently bind to al...

Oral healthcare plays an important role in the prevention of opportunistic infections and aspiration pneumonia in the physically vulnerable elderly. Oral healthcare, consisting of brushing after each meal, cleaning dentures, and receiving professional oral health care, plays a vital role in reducing the incidence of such diseases1-3. In particular, poor oral hygiene is strongly associated with aspiration pneumonia in the physically vulnerable elderly. Therefore, more attention should be paid to the oral health care of elderly patients, who have limited ability to clean their dentures by themselves4.
Even in developed countries, the use of acrylic, resin-based removable dentures remains the most common treatment option for edentulous elderly patients5. Given their high water absorption capacity, microporous surface, and hydrophobic nature, acrylic denture bases constructed from polymethyl methacrylate (PMMA) easily accumulate dental plaque on their surfaces, which is called denture plaque.
2-Methacryloyloxyethyl phosphorylcholine (MPC) polymers are well-known biomedical polymeric materials6 that have remarkable antithrombogenicity and tissue compatibility because of their high resistance to protein adsorption and cell adhesion7-11. MPC polymer coatings have been applied in various medical devices to prevent infection12 and have been suggested to have the potential to prevent denture plaque accumulation on PMMA denture surfaces13. The challenge in the clinical application of MPC polymers to PMMA dentures is to reliably bind them to PMMA surfaces in a simple and stable manner. Previously, MPC polymers were reported to be stably bound to PMMA surfaces by a grafting technique and to have the potential to inhibit plaque accumulation. However, the grafting technique is not simple and requires specialized equipment, which makes its clinical application challenging. Here, we describe a new MPC coating procedure that utilizes photoreactive phospholipid polymers-specifically, a photoreactive methacrylate derivative, 2-methacryloyloxyethyl-4-azidobenzoate (MPAz)-synthesized to accomplish a variety of surface modifications of different types of materials. MPAz was co-polymerized with MPC polymers and n-butyl methacrylate (BMA) to yield poly (MPC-co-BMA-co-MPAz) (PMBPAz). PMBPAz can covalently bind to the surfaces of PMMA dentures via activation of the azide groups in MPAz under ultraviolet (UV) light irradiation14. The procedure does not require any specialized equipment and can be completed by clinicians within 2 min. We also applied this procedure in a clinical setting and demonstrated its clinical utility and efficacy in inhibiting plaque deposition on removable dentures.

<table border="0" cellpadding="0" cellspacing="0" width="695">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:236px;">Ultrasonic Cleaner</td>
			<td style="width:104px;">Aiwa Medical Engineering</td>
			<td style="width:116px;">AU-12C</td>
			<td style="width:239px;">Clean in distilled water before stain the denture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">UVP UV Crosslinker DL-1000</td>
			<td>Funakoshi</td>
			<td>95-0174-03</td>
			<td>UV light irradiation for 2min before use</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Lightbox S</td>
			<td>Suntec</td>
			<td align="right">6542</td>
			<td>capturing in this box after stain the denture</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Adobe Photoshop CS6 Extended</td>
			<td>Adobe</td>
			<td></td>
			<td>Calucurate and quantify</td>
		</tr>
	</tbody>
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2-methacryloyloxyethyl phosphorylcholine polymer treatment of complete dentures to inhibit denture plaque deposition

Removable dentures made of poly (methyl methacrylate) (PMMA) are prone to bacterial adherence and dental plaque formation, which is called denture plaque. Denture plaque-associated infection is a source of serious dental and medical complications in the elderly. 2-Methacryloyloxyethyl phosphorylcholine (MPC) is a well-known biomedical material that exhibits marked antithrombogenicity and tissue compatibility because of its high resistance to protein adsorption and cell adhesion. Therefore, MPC polymer coatings are suggested to have the potential to inhibit plaque deposition on the surface of PMMA dentures. However, coating MPC polymer on the surface of a PMMA denture is a complex procedure that requires specialized equipment, which is regarded as a major barrier to its clinical application. 
Here, we introduce a new MPC polymer treatment procedure that uses poly (MPC-co-BMA-co-MPAz) (PMBPAz) to prevent denture plaque deposition on removable dentures. This procedure enables the MPC coating of PMMA denture surfaces in a simple and stable manner that is resistant to various chemical and mechanical stresses due to the MPC layer of PMBPAz that is covalently bound to the PMMA surface by ultraviolet light irradiation. In addition, the procedure does not require any specialized equipment and can be completed by clinicians within 2 min. We applied this procedure in a clinical setting and demonstrated its clinical utility and efficacy in inhibiting plaque deposition on removable dentures.

PMBPAz treatment enables the MPC coating of PMMA surfaces through a simple and short method and maintains the plaque inhibition effect of the MPC polymer. This procedure does not require any specialized equipment and can be performed chair-side by clinicians within 2 min. Following protocol step 2, the PMBPAz treatment of removable complete dentures from 11 edentulous patients was successfully conducted in a clinical setting without any substantial problems. The mean percentage plaque ind...

Watch this Scientific Journal Video about 2-Methacryloyloxyethyl Phosphorylcholine Polymer Treatment of Complete Dentures to Inhibit Denture Plaque Deposition at JoVE.com

2-Methacryloyloxyethyl Phosphorylcholine Polymer Treatment of Complete Dentures to Inhibit Denture Plaque Deposition

Removable poly(methyl methacrylate) (PMMA) dentures are prone to bacterial adherence and plaque formation. Denture plaque-associated infection is a source of serious dental and medical complications in the elderly. This paper introduces a novel protocol to treat PMMA dentures with 2-methacryloyloxyethyl phosphorylcholine polymer, poly(MPC-co-BMA-co-MPAz), to suppress plaque deposition on PMMA dentures.

Removable dentures made of poly (methyl methacrylate) (PMMA) are prone to bacterial adherence and dental plaque formation, which is called denture plaque. ...

The overall goal of this experiment is to evaluate the effect of the new MPC polymer coating to prevent denture plaque deposition. This means that it can help answer key questions in the field of oral health care of the elderly population, such as how we can improve their denture hygiene. The main advantage of this technique is that dental clinicians do not have to prepare any specialized equipment, and it can be performed in a clinical office within two minutes.Implications of this technique, extend to the prevention of a variety of denture associated health problems, such as periodontal disease, denture stomatitis, and aspiration pneumonia. This method can provide insight into the simple and quick treatment of MPC polymer for complete dentures. It can also be applied to medical devices, for orthopedics.To begin the experiment, obtain the previously synthesized PMBPAz polymer. Synthesize the chilled photoreactive MPC polymer, PMBPAz, using conventional radical polymerization of MPC, BMA, and MPAz. Allow the PMBPAz ethanol solution to stand for 30 minutes at room temperature, before treating the PMMA surface.Using a denture brush, mechanically clean the denture for three minutes. Then, chemically clean the denture for five minutes in an ultrasonic bath sonicator, with a denture cleaner containing 2.0 percent sodium hypochloride. Before performing the surface modification with PMBPAz, wash the denture surface by immersion in ethanol.After the ethanol wash, allow the surface to air dry for one minute. Prepare one milliliter of 0.5 percent weight PMBPAz ethanol solution, from the previously prepared stock, and then let stand to allow the ethanol to evaporate. Next, with a brush applicator, apply the PMBPAz ethanol solution directly to the entire surface of the denture.Keep the denture at room temperature, and add atmospheric pressure for 10 minutes, to allow the solvent to evaporate in an ethanol vapor atmosphere. Irradiate the denture surface with UV light. Then immerse the PMBPAz-treated denture in distilled water for five minutes before use.Collect the denture that a patient has used for two weeks. Rinse the denture with tap water to remove any loose food particles, and then stain the denture with a 0.25 percent methylene blue disclosing solution for one minute in a polypropylene container. Clean any stains present on the denture surface in distilled water, using an ultrasonic bath sonicator.Next, prepare imaging to capture images at a 90 degree angle, on a wax seat, with a digital camera, with a white light system. Obtain images from three different directions to get mucosal, right, and left polished surface images. Then calculate the stained area, and quantify it using an image analysis software, for the entire denture surface.Select the denture area using the magnetic lasso tool, from the captured denture image. Next, change the red-colored channel to highlight the plaque area from the denture area image. Using the magic wand tool, and the select similar tool, select all plaque areas with a tolerance level of eight in the denture area.Count the total number of pixels for each image, then calculate the percentage plaque index of the area covered on the denture, from the pixel count of these images. Finally, evaluate the statistical differences between the stained areas on the PMBPAz-treated and untreated dentures. The total denture area of the mucosal surface after staining and digitization of both untreated, and the plaque area of the mucosal surface after selection, reveal that the stained plaque areas were consistently and markedly decreased by PMBPAz treatment.The mean percentages of the number of plaque pixels on the mucosal and polished surfaces of untreated and PMBPAz-treated dentures demonstrate that PMBPAz treatment of the mucosal and polished surfaces significantly inhibited the deposition of denture plaque. The development of this technique paved a new path for researchers to explore efficient and practical methods to prevent plaque-associated infections. Once mastered, this technique can be done in 30 minutes, if it is performed properly.After watching this video, you should have a good understanding of how to prevent opportunistic infections associated with denture plaque accumulation.

2-methacryloyloxyethyl-phosphorylcholine-polymer-treatment-complete

Research

JoVE Journal

Medicine

In vivo Near Infrared Fluorescence (NIRF) Intravascular Molecular Imaging of Inflammatory Plaque, a Multimodal Approach to Imaging of Atherosclerosis

The vascular response to injury is a well-orchestrated inflammatory response triggered by the accumulation of macrophages within the vessel wall leading to an accumulation of lipid-laden intra-luminal plaque, smooth muscle cell proliferation and progressive narrowing of the vessel lumen. The formation of such vulnerable plaques prone to rupture underlies the majority of cases of acute myocardial infarction. The complex molecular and cellular inflammatory cascade is orchestrated by the recruitment of T lymphocytes and macrophages and their paracrine effects on endothelial and smooth muscle cells.1
Molecular imaging in atherosclerosis has evolved into an important clinical and research tool that allows in vivo visualization of inflammation and other biological processes. Several recent examples demonstrate the ability to detect high-risk plaques in patients, and assess the effects of pharmacotherapeutics in atherosclerosis.4 While a number of molecular imaging approaches (in particular MRI and PET) can image biological aspects of large vessels such as the carotid arteries, scant options exist for imaging of coronary arteries.2 The advent of high-resolution optical imaging strategies, in particular near-infrared fluorescence (NIRF), coupled with activatable fluorescent probes, have enhanced sensitivity and led to the development of new intravascular strategies to improve biological imaging of human coronary atherosclerosis.
Near infrared fluorescence (NIRF) molecular imaging utilizes excitation light with a defined band width (650-900 nm) as a source of photons that, when delivered to an optical contrast agent or fluorescent probe, emits fluorescence in the NIR window that can be detected using an appropriate emission filter and a high sensitivity charge-coupled camera. As opposed to visible light, NIR light penetrates deeply into tissue, is markedly less attenuated by endogenous photon absorbers such as hemoglobin, lipid and water, and enables high target-to-background ratios due to reduced autofluorescence in the NIR window. Imaging within the NIR 'window' can substantially improve the potential for in vivo imaging.2,5
Inflammatory cysteine proteases have been well studied using activatable NIRF probes10, and play important roles in atherogenesis. Via degradation of the extracellular matrix, cysteine proteases contribute importantly to the progression and complications of atherosclerosis8. In particular, the cysteine protease, cathepsin B, is highly expressed and colocalizes with macrophages in experimental murine, rabbit, and human atheromata.3,6,7 In addition, cathepsin B activity in plaques can be sensed in vivo utilizing a previously described 1-D intravascular near-infrared fluorescence technology6, in conjunction with an injectable nanosensor agent that consists of a poly-lysine polymer backbone derivatized with multiple NIR fluorochromes (VM110/Prosense750, ex/em 750/780nm, VisEn Medical, Woburn, MA) that results in strong intramolecular quenching at baseline.10 Following targeted enzymatic cleavage by cysteine proteases such as cathepsin B (known to colocalize with plaque macrophages), the fluorochromes separate, resulting in substantial amplification of the NIRF signal. Intravascular detection of NIR fluorescence signal by the utilized novel 2D intravascular NIRF catheter now enables high-resolution, geometrically accurate in vivo detection of cathepsin B activity in inflamed plaque.
In vivo molecular imaging of atherosclerosis using catheter-based 2D NIRF imaging, as opposed to a prior 1-D spectroscopic approach,6 is a novel and promising tool that utilizes augmented protease activity in macrophage-rich plaque to detect vascular inflammation.11,12 The following research protocol describes the use of an intravascular 2-dimensional NIRF catheter to image and characterize plaque structure utilizing key aspects of plaque biology. It is a translatable platform that when integrated with existing clinical imaging technologies including angiography and intravascular ultrasound (IVUS), offers a unique and novel integrated multimodal molecular imaging technique that distinguishes inflammatory atheromata, and allows detection of intravascular NIRF signals in human-sized coronary arteries.

In vivo Near Infrared Fluorescence NIRF Intravascular Molecular Imaging of Inflammatory Plaque, a Multimodal Approach to Imaging of Atherosclerosis

We detail a new near-infrared fluorescence (NIRF) catheter for 2-dimensional intravascular molecular imaging of plaque biology in vivo. The NIRF catheter can visualize key biological processes such as inflammation by reporting on the presence of plaque-avid activatable and targeted NIR fluorochromes. The catheter utilizes clinical engineering and power requirements and is targeted for application in human coronary arteries. The following research study describes a multimodal imaging strategy that utilizes a novel in vivo intravascular NIRF catheter to image and quantify inflammatory plaque in proteolytically active inflamed rabbit atheromata.

The vascular response to injury is a well-orchestrated inflammatory response triggered by the accumulation of macrophages within the vessel wall leading ...

Mouse Complete Stasis Model of Inferior Vena Cava Thrombosis

Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). In the United States (U.S.), the high morbidity and mortality rates make VTE a serious health concern 1-2. After heart disease and stroke, VTE is the third most common vascular disease 3. In the U.S. alone, there is an estimated 900,000 people affected each year, with 300,000 deaths occurring annually 3. A reliable in vivo animal model to study the mechanisms of this disease is necessary.
The advantages of using the mouse complete stasis model of inferior vena cava thrombosis are several. The mouse model allows for the administration of very small volumes of limited availability test agents, reducing costs dramatically. Most promising is the potential for mice with gene knockouts that allow specific inflammatory and coagulation factor functions to be delineated. Current molecular assays allow for the quantitation of vein wall, thrombus, whole blood, and plasma for assays. However, a major concern involving this model is the operative size constraints and the friability of the vessels. Also, due to the small IVC sample weight (mean 0.005 grams) it is necessary to increase animal numbers for accurate statistical analysis for tissue, thrombus, and blood assays such as real-time polymerase chain reaction (RT-PCR), western blot, enzyme-linked immunosorbent (ELISA), zymography, vein wall and thrombus cellular analysis, and whole blood and plasma assays 4-8.
The major disadvantage with the stasis model is that the lack of blood flow inhibits the maximal effect of administered systemic therapeutic agents on the thrombus and vein wall.

The mouse complete stasis model of inferior vena cava thrombosis yields quantifiable amounts of vein wall tissue and thrombus. It has proven useful for evaluating interactions between the vein wall and the occlusive thrombus and in assessing the progression from acute to chronic inflammation.

Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE).  In the United States (U.S.), the high morbidity and ...

The Measurement and Treatment of Suppression in Amblyopia

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current estimates put the prevalence of amblyopia at approximately 1-3%1-3, the majority of cases being monocular2. Amblyopia is most frequently caused by ocular misalignment (strabismus), blur induced by unequal refractive error (anisometropia), and in some cases by form deprivation.
Although amblyopia is initially caused by abnormal visual input in infancy, once established, the visual deficit often remains when normal visual input has been restored using surgery and/or refractive correction. This is because amblyopia is the result of abnormal visual cortex development rather than a problem with the amblyopic eye itself4,5 . Amblyopia is characterized by both monocular and binocular deficits6,7 which include impaired visual acuity and poor or absent stereopsis respectively. The visual dysfunction in amblyopia is often associated with a strong suppression of the inputs from the amblyopic eye under binocular viewing conditions8. Recent work has indicated that suppression may play a central role in both the monocular and binocular deficits associated with amblyopia9,10 .
Current clinical tests for suppression tend to verify the presence or absence of suppression rather than giving a quantitative measurement of the degree of suppression. Here we describe a technique for measuring amblyopic suppression with a compact, portable device11,12 . The device consists of a laptop computer connected to a pair of virtual reality goggles. The novelty of the technique lies in the way we present visual stimuli to measure suppression. Stimuli are shown to the amblyopic eye at high contrast while the contrast of the stimuli shown to the non-amblyopic eye are varied. Patients perform a simple signal/noise task that allows for a precise measurement of the strength of excitatory binocular interactions. The contrast offset at which neither eye has a performance advantage is a measure of the "balance point" and is a direct measure of suppression. This technique has been validated psychophysically both in control13,14 and patient6,9,11 populations.
In addition to measuring suppression this technique also forms the basis of a novel form of treatment to decrease suppression over time and improve binocular and often monocular function in adult patients with amblyopia12,15,16 . This new treatment approach can be deployed either on the goggle system described above or on a specially modified iPod touch device15.

Amblyopia is a developmental disorder of the visual cortex that is often accompanied by strong suppression of one eye. We present a new technique for measuring and treating interocular suppression in patients with amblyopia that can be deployed using virtual reality goggles or a portable iPod Touch device.

Amblyopia, a developmental disorder of the visual cortex, is one of the leading causes of visual dysfunction in the working age population. Current ...

The Goeckerman Regimen for the Treatment of Moderate to Severe Psoriasis

Psoriasis is a chronic, immune-mediated inflammatory skin disease affecting approximately 2-3% of the population. The Goeckerman regimen consists of exposure to ultraviolet B (UVB) light and application of crude coal tar (CCT). Goeckerman therapy is extremely effective and relatively safe for the treatment of psoriasis and for improving a patient's quality of life. In the following article, we present our protocol for the Goeckerman therapy that is utilized specifically at the University of California, San Francisco. This protocol details the preparation of supplies, administration of phototherapy and application of topical tar. This protocol also describes how to assess the patient daily, monitor for adverse effects (including pruritus and burning), and adjust the treatment based on the patient's response. Though it is one of the oldest therapies available for psoriasis, there is an absence of any published videos demonstrating the process in detail. The video is beneficial for healthcare providers who want to administer the therapy, for trainees who want to learn more about the process, and for prospective patients who want to undergo treatment for their cutaneous disease.

Psoriasis is a chronic, immune-mediated inflammatory skin disease. The Goeckerman regimen, formulated for the treatment of psoriasis, consists of exposure to ultraviolet B (UVB) light and application of crude coal tar (CCT). The following protocol is for the administration of Goeckerman therapy for the treatment of moderate-to-severe psoriasis.

Psoriasis is a  chronic, immune-mediated inflammatory skin disease affecting approximately 2-3%  of the population. The Goeckerman regimen consists of ...

A Human Ex Vivo Atherosclerotic Plaque Model to Study Lesion Biology

Atherosclerosis is a chronic inflammatory disease of the vasculature. There are various methods to study the inflammatory compound in atherosclerotic lesions. Mouse models are an important tool to investigate inflammatory processes in atherogenesis, but these models suffer from the phenotypic and functional differences between the murine and human immune system. In vitro cell experiments are used to specifically evaluate cell type-dependent changes caused by a substance of interest, but culture-dependent variations and the inability to analyze the influence of specific molecules in the context of the inflammatory compound in atherosclerotic lesions limit the impact of the results. In addition, measuring levels of a molecule of interest in human blood helps to further investigate its clinical relevance, but this represents systemic and not local inflammation. Therefore, we here describe a plaque culture model to study human atherosclerotic lesion biology ex vivo. In short, fresh plaques are obtained from patients undergoing endarterectomy or coronary artery bypass grafting and stored in RPMI medium on ice until usage. The specimens are cut into small pieces followed by random distribution into a 48-well plate, containing RPMI medium in addition to a substance of interest such as cytokines or chemokines alone or in combination for defined periods of time. After incubation, the plaque pieces can be shock frozen for mRNA isolation, embedded in Paraffin or OCT for immunohistochemistry staining or smashed and lysed for western blotting. Furthermore, cells may be isolated from the plaque for flow cytometry analysis. In addition, supernatants can be collected for protein measurement by ELISA. In conclusion, the presented ex vivo model opens the possibility to further study inflammatory lesional biology, which may result in identification of novel disease mechanisms and therapeutic targets.

A Human Ex Vivo Atherosclerotic Plaque Model to Study Lesion Biology

Atherosclerosis is a chronic inflammatory process. This manuscript illustrates an easy to use ex vivo model to investigate fresh carotid or coronary artery plaques. The ex vivo model allows for the investigation of potential substances on the inflammatory milieu in human atherosclerotic lesions and results can be analyzed by various methods.

Atherosclerosis is a chronic inflammatory disease of the vasculature. There are various methods to study the inflammatory compound in atherosclerotic ...

Network Analysis of Foramen Ovale Electrode Recordings in Drug-resistant Temporal Lobe Epilepsy Patients

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control seizures. However, a significant minority of patients continues to exhibit post-operative seizures, even in those cases in which the suspected source of seizures has been correctly localized and resected. The protocol presented here combines a clinical procedure routinely employed during the pre-operative evaluation of temporal lobe epilepsy (TLE) patients with a novel technique for network analysis. The method allows for the evaluation of the temporal evolution of mesial network parameters. The bilateral insertion of foramen ovale electrodes (FOE) into the ambient cistern simultaneously records electrocortical activity at several mesial areas in the temporal lobe. Furthermore, network methodology applied to the recorded time series tracks the temporal evolution of the mesial networks both interictally and during the seizures. In this way, the presented protocol offers a unique way to visualize and quantify measures that considers the relationships between several mesial areas instead of a single area.

This protocol describes a procedure to track the evolution of mesial network measures in temporal lobe epilepsy (TLE) patients. It is based on the combination of intracranial recordings with a novel numerical technique for data analysis. Specifically, we present a protocol for network analyses of foramen ovale recordings.

Approximately 30% of epilepsy patients are refractory to antiepileptic drugs. In these cases, surgery is the only alternative to eliminate/control ...

Complete and Partial Aortic Occlusion for the Treatment of Hemorrhagic Shock in Swine

Hemorrhage remains the leading cause of preventable deaths in trauma. Endovascular management of non-compressible torso hemorrhage has been at the forefront of trauma care in recent years. Since complete aortic occlusion presents serious concerns, the concept of partial aortic occlusion has gained a growing attention. Here, we present a large animal model of hemorrhagic shock to investigate the effects of a novel partial aortic balloon occlusion catheter and compare it with a catheter that works on the principles of complete aortic occlusion. Swine are anesthetized and instrumented in order to conduct controlled fixed-volume hemorrhage, and hemodynamic and physiological parameters are monitored. Following hemorrhage, aortic balloon occlusion catheters are inserted and inflated in the supraceliac aorta for 60 min, during which the animals receive whole-blood resuscitation as 20% of the total blood volume (TBV). Following balloon deflation, the animals are monitored in a critical care setting for 4 h, during which they receive fluid resuscitation and vasopressors as needed. The partial aortic balloon occlusion demonstrated improved distal mean arterial pressures (MAPs) during the balloon inflation, decreased markers of ischemia, and decreased fluid resuscitation and vasopressor use. As swine physiology and homeostatic responses following hemorrhage have been well-documented and are like those in humans, a swine hemorrhagic shock model can be used to test various treatment strategies. In addition to treating hemorrhage, aortic balloon occlusion catheters have become popular for their role in cardiac arrest, cardiac and vascular surgery, and other high-risk elective surgical procedures.

Here, we present a protocol demonstrating a hemorrhagic shock model in swine that uses aortic occlusion as a bridge to definitive care in trauma. This model has application in testing a wide range of surgical and pharmacological therapeutic strategies.

Hemorrhage remains the leading cause of preventable deaths in trauma. Endovascular management of non-compressible torso hemorrhage has been at the ...

Predicting Treatment Response to Image-Guided Therapies Using Machine Learning: An Example for Trans-Arterial Treatment of Hepatocellular Carcinoma

Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. The objective of this study was to develop a method to predict response to intra-arterial treatment prior to intervention.
The method provides a general framework for predicting outcomes prior to intra-arterial therapy. It involves pooling clinical, demographic and imaging data across a cohort of patients and using these data to train a machine learning model. The trained model is applied to new patients in order to predict their likelihood of response to intra-arterial therapy.
The method entails the acquisition and parsing of clinical, demographic and imaging data from N patients who have already undergone trans-arterial therapies. These data are parsed into discrete features (age, sex, cirrhosis, degree of tumor enhancement, etc.) and binarized into true/false values (e.g., age over 60, male gender, tumor enhancement beyond a set threshold, etc.). Low-variance features and features with low univariate associations with the outcome are removed. Each treated patient is labeled according to whether they responded or did not respond to treatment. Each training patient is thus represented by a set of binary features and an outcome label. Machine learning models are trained using N - 1 patients with testing on the left-out patient. This process is repeated for each of the N patients. The N models are averaged to arrive at a final model.
The technique is extensible and enables inclusion of additional features in the future. It is also a generalizable process that may be applied to clinical research questions outside of interventional radiology. The main limitation is the need to derive features manually from each patient. A popular modern form of machine learning called deep learning does not suffer from this limitation, but requires larger datasets.

Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. A method for predicting response to these therapies is proposed. The technique uses pre-procedural clinical, demographic, and imaging information to train machine learning models capable of predicting response prior to treatment.

Intra-arterial therapies are the standard of care for patients with hepatocellular carcinoma who cannot undergo surgical resection. The objective of this ...

Direct Intrabronchial Administration to Improve the Selective Agent Deposition Within the Mouse Lung

Intratracheal (IT) administration of experimental agents is an essential technique in murine models of diffuse lung diseases, such as bleomycin-induced pulmonary fibrosis.&#160; However, distribution of intratracheally-administered agents to the distal mouse lung is often asymmetric, with lung parenchymal concentrations increased in the smaller (but equally accessible) left lung of the mouse.&#160; Described in this report is a novel intrabronchial (IB) approach to cannulate the left and/or right lungs of living mice non-operatively.&#160; It is also demonstrated how this approach can be used to selectively administer agents to one lung or adapted (via dose-adjusted IB delivery) to improve the left-right symmetry of lung delivery of experimental agents, thereby improving models of diffuse lung disease such as bleomycin-induced pulmonary fibrosis.

Intratracheal (IT) administration of experimental agents in mice often results in asymmetric delivery to the distal lungs.&#160; In this report, we describe a direct intrabronchial (IB) approach to cannulate each lung in living mice non-operatively.&#160; This approach can be used to selectively administer agents to one lung or may be adapted to improve the symmetric agent delivery to both lungs.

Intratracheal (IT) administration of experimental agents is an essential technique in murine models of diffuse lung diseases, such as bleomycin-induced ...

Establishment of a Severe Dry Eye Model Using Complete Dacryoadenectomy in Rabbits

Dry eye disease (DED) is a complex disease with multiple etiologies and variable symptoms, having ocular surface inflammation as its key pathophysiologic step. Despite advances in our understanding of DED, significant knowledge gaps remain. Advances are limited in part due to the lack of informative animal models. The authors recently reported on a method of DED induced by injecting all orbital lacrimal gland (LG) tissues with the lectin concanavalin A. Here, we report a novel model of aqueous-deficient DED based on the surgical resection of all orbital LG (dacryoadenectomy) tissues. Both methods use rabbits because of their similarity to human eyes in terms of the size and structure of the ocular surface. One week after removal of the nictitating membrane, the orbital superior LG was surgically removed under anesthesia, followed by removal of the palpebral superior LG, and finally removal of the inferior LG. Dacryoadenectomy induced severe DED, evidenced by a marked reduction in the tear break up time test and the Schirmer&#39;s tear test, and significantly increased tear osmolarity and rose bengal staining. Dacryoadenectomy-induced DED lasted at least eight weeks. There were no complications and animals tolerated the procedure well. The technique can be mastered relatively easily by those with adequate surgical experience and appreciation of the relevant rabbit anatomy. Since this model recapitulates the features of human aqueous-deficient DED, it is suitable for studies of ocular surface homeostasis, DED, and candidate therapeutics.

A novel approach is presented to induce chronic dry eye disease in rabbits by surgically removing all orbital lacrimal glands. This method, distinct from those previously reported, produces a stable, reproducible model of aqueous deficient dry eye well suited to study tear physiology and pathophysiology and ocular therapeutics.

Dry eye disease (DED) is a complex disease with multiple etiologies and variable symptoms, having ocular surface inflammation as its key pathophysiologic ...