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			<p class="Type-of-Article">&nbsp;</p>
			<p class="Type-of-Article"><span class="CharOverride-1">Research Article</span></p>
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			<p class="title- ParaOverride-1">&nbsp;</p>
			<p class="title- ParaOverride-1">Silver Nanoparticles Embedded Photosensitive Silicon as Catheter Materials </p>
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			<p class="Authors ParaOverride-1">&nbsp;</p>
			<p class="Authors ParaOverride-1"><span class="CharOverride-2">Swati</span><span class="CharOverride-2"> Dahiya</span><span class="CharOverride-3">1*</span><span class="CharOverride-2">, </span><span class="CharOverride-2">Neha Bhardwaj</span><span class="CharOverride-3">2</span><span class="CharOverride-2">, </span><span class="CharOverride-2">Sanjeev Bhardwaj</span><span class="CharOverride-3">2</span><span class="CharOverride-2">, J</span><span class="CharOverride-2" lang="en-US">yotsana</span><span class="CharOverride-2"> Mehta</span><span class="CharOverride-3">2</span><span class="CharOverride-2">, Arun Sehgal, Minakshi Prasad</span><span class="CharOverride-3">3</span></p>
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			<p class="Affiliations ParaOverride-1"><span class="CharOverride-4">1</span>Department of Veterinary Microbiology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar-125004, Haryana; <span class="CharOverride-4">2</span>Central Scientific Instrumentation Organisation (CSIO), Sector-30C, Chandigarh-160030; <span class="CharOverride-4">3</span>Department of Animal Biotechnology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar-125004, Haryana, India.</p>
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			<p class="Abstract">&nbsp;</p>
			<p class="Abstract"><span class="CharOverride-5">Abstract</span> | <span lang="en-US">Biofilm growth on catheter surface is a challenge for various biomedical applications. Microbial colonization on catheter’s surface leads to many infections. Silicone polymer is a routine material for catheter fabrication. In the present work, silver nanoparticles (NPs) and photosensitive non-toxic dye toluidiune blue (TB) embedded silicon polymer is synthesised by swell encapsulation method and characterised by UV spectroscopy. The embedded polymer showed high bactericidal activity against gram-positive bacteria </span><span class="CharOverride-6" lang="en-US">Staphylococcus aureus</span><span lang="en-US"> (</span><span class="CharOverride-6" lang="en-US">S. aureus</span><span lang="en-US">) and gram-negative </span><span class="CharOverride-6" lang="en-US">Proteus mirabilis</span><span lang="en-US"> (</span><span class="CharOverride-6" lang="en-US">P. mirabilis</span><span lang="en-US">) with least leaching effects which suggests their usage as a new weapon to fight catheter related infections.</span></p>
		  <p class="Abstract">&nbsp;</p>
			<p class="Abstract ParaOverride-1"><span class="CharOverride-5">Keywords </span>| <span lang="en-US">Catheter, Photosensitizer dye, Toluidine blue, Silver nanoparticles, Bactericidal</span></p>
		  <p class="Abstract ParaOverride-1">&nbsp;</p>
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			<p class="Editor----Citation"><span class="CharOverride-7">Editor</span> | Sandip Kumar Khurana, Principal Scientist, National Center on Equines (NRCE), Sirsa Road, Hisar, Haryana, 125004, India.</p>
			<p class="Editor----Citation"><span class="CharOverride-7">Special Issue</span> | 1(2015) “Biotechnological and molecular approaches for diagnosis, prevention and control of infectious diseases of animals”</p>
			<p class="Editor----Citation"><span class="CharOverride-5">Received</span> | December 04, 2014; <span class="CharOverride-5">Revised</span> | March 21, 2015; <span class="CharOverride-5">Accepted</span> | March 22, 2015; <span class="CharOverride-5">Published</span> | March 31, 2015&#9;&#9;</p>
			<p class="Editor----Citation"><span class="CharOverride-5">*Correspondence</span> | Swati Dahiya, Lala lajpat Rai University of Vetrinary and Animal Sciences, Hisar, Haryana, India; <span class="CharOverride-5">Email: </span>swatidahiya@yahoo.co.in</p>
			<p class="Editor----Citation"><span class="CharOverride-5">Citation</span> | Dahiya S, Bhardwaj N, Bhardwaj S, Mehta J, Sehgal A, Prasad M (2015). Silver nanoparticles embedded photosensitive silicon as catheter materials. Adv. Anim. Vet. Sci. 3(1s): 10-15.  </p>
			<p class="Editor----Citation"><span class="CharOverride-7">DOI</span> | <a href="http://dx.doi.org/10.14737/journal.aavs/2015/3.1s.10.15"><span class="Hyperlink CharOverride-9">http://dx.doi.org/10.14737/journal.aavs/2015/3.1s.10.15</span></a></p>
			<p class="Editor----Citation"><span class="Editor---Citation CharOverride-5" lang="en-US">ISSN </span><span class="Editor---Citation CharOverride-5" lang="en-US">(</span><span class="Editor---Citation CharOverride-5" lang="en-US">Online</span><span class="Editor---Citation CharOverride-5" lang="en-US">)</span> | 2307-8316; <span class="Editor---Citation CharOverride-5" lang="en-US">ISSN </span><span class="Editor---Citation CharOverride-5" lang="en-US">(Print) </span> | 2309-3331</p>
			<p class="Editor----Citation"><span class="CharOverride-7">Copyright </span>© 2015 Dahiya et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p>
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			<p class="Heading-1--Introduction----">&nbsp;</p>
		  <p class="Heading-1--Introduction----">Introduction</p>
			<p class="Caps-on-First-Para">&nbsp;</p>
			<p class="Caps-on-First-Para"><span class="_idGenDropcap-1">C</span>atheter is a thin, flexible, sterile tube made up of flexible polymeric materials such as silicone and polyurethane having versatile biomedical applications (<a href="#Trautner-BW--Darouiche-RO--2004"><span class="Hyperlink">Trautner and Darouiche, 2004</span></a>). The surface of a catheter often gets colonized by micro-organisms that form biofilms on their surface, which results catheter-associated infections (CAIs). These infections can consequently lead to destruction of tissues, systemic dissemination of the pathogen and dysfunction of the device, thus, resulting in serious illness and death of the individual (<a href="#Hall-Stoodley-L--Costerton-JW--Stoodley-P--2004"><span class="Hyperlink">Hall-Stoodley et al., </span><span class="Hyperlink">2004</span></a>). The hospital acquired bloodstream infections have a mortality rate of 10-25% and are generally caused by usage of two common types of catheter i.e. intravascular catheter and urinary catheter (<a href="#Maki-D--Mermel-L--1998-."><span class="Hyperlink">Maki and Mermel, 1998</span></a>). The annual usage of central venous catheters in US alone is around 5 million, of which about 3-8% result in bloodstream infections with a mortality rate of ca. 15% (<a href="#Trautner-BW--Darouiche-RO--2004"><span class="Hyperlink">Trautner and Darouiche, 2004</span></a>). Also, urinary catheters are used at large scale (more than 30 million) every year in US, with an infection rate of about 10-30%, of which &lt;1% result in death (<a href="#Veenstra-D--Saint-S--Sullivan-SJ--1999-"><span class="Hyperlink">Veenstra et al., 1999</span></a>).</p>
		  <p class="Caps-on-First-Para">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">Most of the CAIs are caused by biofilm forming bacteria such as <span class="CharOverride-6">Escherichia coli, Pseudomonas aeruginosa, Klebsilella pneumonia, Proteus mirabilis, Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus spp., Stenotrophomonas</span> and<span class="CharOverride-6"> Candida species </span>posing a critical medical problem worldwide<span class="CharOverride-6"> </span>(<a href="#Trautner-BW--Darouiche-RO--2004"><span class="Hyperlink">Trautner and Darouiche, 2004</span></a>; <a href="#Tenke-P--Jackel-M--Nagy-E--2004"><span class="Hyperlink">Tenke et al., 2004</span></a>). Among these biofilm-forming bacteria, <span class="CharOverride-6">S. aureus</span> is the most commonly found gram-positive bacterium causing 50%–70% catheter associated biofilm infections (<a href="#Agarwal-A--Singh-KP--Jain-A--2010"><span class="Hyperlink">Agarwal et al., 2010</span></a>; <a href="#Walz-JM--Memtsoudis-SG--Heard-SO--2010-."><span class="Hyperlink">Walz et al., 2010</span></a>). In addition, there is an increasing rise of antibiotic resistance in <span class="CharOverride-6">S. aureus</span> which further raises concern about its prevalence in medical institutes and hospitals (<a href="#Chambers-HF--DeLeo-FR--2009-."><span class="Hyperlink">Chambers and DeLeo, 2009</span></a>). <span class="CharOverride-6">P. mirabilis </span>is also a biofilm forming gram-negative bacterium with the greatest ability to attach to a catheter’s surface (<a href="#Roberts-JA--Fussell-EN-and-Kaack-MB--1990-."><span class="Hyperlink">Robert et al., 1990</span></a>; <a href="#Warren-JW--1996"><span class="Hyperlink">Warren 1996</span></a>).<span class="CharOverride-6"> </span>It is the third most common cause of urinary tract infections (12%) and the second most common cause of catheter associated bacteriuria (15%) in long term catheterized patients. The biofilms formed by <span class="CharOverride-6">P. mirabilis </span>on urinary catheter surfaces account for upto 30% of all urinary tract stones (<a href="#Hochreiter-W--Knoll-T--Hess-B--2003"><span class="Hyperlink">Hochreiter et al., 2003</span></a>). The crystalline biofilms formed by this bacterium can even lead to blockage of catheters and bladder stone formation (<a href="#Sabbuba-NA--Stickler-DJ--Mahenthiralingam-E--Painter-DJ--Parkin-J--Feneley-RC--2004"><span class="Hyperlink">Sabbuba et al., 2004</span></a>). Taken together, the burden on healthcare system by such biofilm forming microbes is enormous and the prevention of CAIs caused by such microbes is a major challenge in biomedical field due to the growing antibiotic resistance in micro-organisms (<a href="#Gould-IM--2008-"><span class="Hyperlink">Gould, 2008</span></a>). A multitude of methods have been described previously for prevention of such infections by many researchers but the recent methods involve modification of catheter surfaces either by coating or by impregnation of antibacterial agents or antiseptics (<a href="#Siddiq-DM--Darouiche-RO--2012"><span class="Hyperlink">Siddiq and Darouiche, 2012</span></a>). Catheter materials that resist encrustation by bacterial biofilms can be developed either by incorporation of an antimicrobial agent into the polymer (<a href="#Darouiche-RO--Raad-II--1997-"><span class="Hyperlink">Darouiche and Raad, 1997</span></a>) or by developing surface modified materials which prevent the adherence of bacterial cells (<a href="#Stickler-DJ--Evans-A--Morris-N--Hughes-G--2002"><span class="Hyperlink">Stickler et al.</span><span class="Hyperlink">, 2002</span></a>). The use of silver in particular has shown cidal effect against many of the bacteria associated with CAIs (<a href="#Furno-F--Morley-KS--Wong-B--Sharp-BL--Arnold-PL--Howdle-SM--2004"><span class="Hyperlink">Furno et al., 2004</span></a>; <a href="#Kim-JS--Kuk-E--Yu-KN--Kim-JH--Park-SJ--Lee-2007"><span class="Hyperlink">Kim et al., 2007</span></a>). Due to the small size and higher surface-to-volume ratio of metallic nanoparticles (e.g. silver NPs), they have an increased contact area with the microorganism and thus acquire higher antibacterial activity in comparison to the conventional antibiotics or antiseptics (<a href="#Pan-cek-A--Kv-tek-L--Prucek-R--Kol-r-M--Vecerov--R--Piz-rov--N--2006-"><span class="Hyperlink">Panacek et al., 2006</span></a>). Also, the NPs can target different functions of bacterial cell membranes, such as permeability and respiration. Accumulation of silver on negatively charged parts of the bacterial cell membrane leads to perforation of the membrane, leakage of the cellular compounds and finally cell death.  In addition, NPs can penetrate inside bacterial cell and disturb cell functions by reacting with phosphorous containing compounds such as DNA or sulphur containing proteins (<a href="#Gordon-O--Vig-Slenters-T--Brunetto-PS--2010"><span class="Hyperlink">Gordon et al., 2010</span></a>; <a href="#Singh-M--Sing-S--Prasad-S--Gambhir-IS--2008-"><span class="Hyperlink">Singh et al., 2008</span></a>). The decreased probability of developing NP resistance in bacteria due to complex action mechanisms also makes their usage better in comparison to traditional antibiotics (<a href="#Chopra-IJ--2007"><span class="Hyperlink">Chopra, 2007</span></a>). The silver NPs are being used to control bacterial growth in a variety of applications such as dental, wound dressings as well as catheters (<a href="#Catauro-M--Raucci-MG--De-Gaetano-FD--Marotta-A--2004"><span class="Hyperlink">Catauro et al., 2004</span></a>; <a href="#Crabtree-JH--Burchette-RJ--Siddiqi-RA--Huen-IT--Handott-LL--Fishman-A--2003"><span class="Hyperlink">Crabtree et al., 2003</span></a>; <a href="#Payne-JL--Ambrosio-AM--2009-"><span class="Hyperlink">Payne et al., 2009</span></a>). Many research groups have demonstrated the reduction in incidence of nosocomial urinary tract infections due to antimicrobial activity of the silver nanoparticles (NPs) and silver alloys in urinary catheters (<a href="#Madeo-M--Davies-D--Johnson-G--Owen-E--Wadsworth-P--Martin-CR--2004"><span class="Hyperlink">Madeo et al., 2004</span></a>; <a href="#Lajcak-M--Heidecke-V--Haude-KH--Rainov-NG--2013-."><span class="Hyperlink">Lajcak et al., 2013</span></a>; <a href="#Woodyard-LL--Bowersock-TL--Turek-JJ--McCabe-GP--De-Ford-J--1996-."><span class="Hyperlink">Woodyard et al, 1996</span></a>). </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">Recently, a new approach to biofilm prevention, based on lethal photosensitization is also being explored. When a photosensitiser dye is exposed to light of appropriate wavelength, it produces a highly reactive oxygen species which destroys the micro-organisms present on catheter surface (<a href="#Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009b"><span class="Hyperlink">Perni et al., 2009b</span></a>; <a href="#Perni-S--Prokopovich-P--Parkin-IP--Wilsona-M-and-Pratten-J--2010-."><span class="Hyperlink">Perni et al., </span><span class="Hyperlink">2010</span></a>). Several organic photosensitiser (dyes) have been reported as light activated antimicrobial agents (LAAA) by embedding them inside a polymer for their antimicrobial activity against <span class="CharOverride-6">S. aureus, S. epidermidis, E. coli </span>and <span class="CharOverride-6">P. aeruoginosa </span>(<a href="#Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009a"><span class="Hyperlink">Perni et al., 2009a</span></a>; <a href="#Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009b"><span class="Hyperlink">Perni et al., 2009b</span></a>; <a href="#Perni-S--Prokopovich-P--Parkin-IP--Wilsona-M-and-Pratten-J--2010-."><span class="Hyperlink">Perni et al., 2010</span></a>; <a href="#Perni-S--Pratten-J--Wilson-M--2011"><span class="Hyperlink">Perni et al., 2011</span></a>). </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">In the present work, synergistic effect of TB dye and silver NPs has been reported for antibacterial activity of silicone polymer based catheters having hybrid properties of both silver nanoparticles and photosensitizer dyes as an effective strategy for preventing CAIs. </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-1--Introduction----">Materials and Methods</p>
		  <p class="Heading-1--Introduction----">&nbsp;</p>
			<p class="Heading-2--History-in-MM-">Materials Used</p>
			<p class="Body-Text">Silicone nipples (Bonne, Tender Flo) were used as the source of liquid silicone polymer/elastomer. The silver nanoparticles (Central Drug House (P) Ltd) and powdered toluidine blue (TB) (S-D Fine Chemicals Limited) were used for embedding inside polymer. A low power laser source (laser diode, wavelength 630-680 nm) was used for the excitation of TB dye. LR grade acetone (S-D Fine Chemicals Limited) and phosphate buffer saline (PBS; HiMedia Laboratories Pvt. Ltd) were used in the study. The bacterial cultures i.e. <span class="CharOverride-6">Staphylococcus aureus </span>(MTCC No. 3160) and <span class="CharOverride-6">Proteus mirabilis </span>(MTCC No.425) were procured from Institute of Microbial Technology, Chandigarh and maintained on nutrient agar (HiMedia Laboratories Pvt. Ltd.). </p>
		  <p class="Body-Text">&nbsp;</p>
			<p class="Heading-2--History-in-MM-">Methods</p>
		  <p class="Heading-2--History-in-MM-">&nbsp;</p>
			<p class="Heading-3 ParaOverride-1">Embedding of Polymer with Dye and Nanoparticles</p>
			<p class="Body-Text ParaOverride-1">The silicone polymer was first cut into square coupons of size around (1x1) cm<span class="CharOverride-4">2</span> or (2x2) cm<span class="CharOverride-4">2</span> or circular discs. Then, TB dye (700 ppm) and silver NPs (100 pm) were incorporated in the silicone polymer coupons by swell-encapsulation-shrinkage method (<a href="#Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009a"><span class="Hyperlink">Perni et al., 2009a</span></a>). </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-3">Characterisation of Embedded Polymer</p>
			<p class="Body-Text ParaOverride-1">The silicone polymers embedded with TB dye and silver NPs were characterised by analysing their absorbance spectrum using UV-VIS spectrophotometer (Specord-205, Analytic Jena, Germany). </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-3">Antibacterial Activity of Polymers</p>
			<p class="Body-Text ParaOverride-1">The antibacterial effects of silicone polymer embedded with TB dye and silver NPs were studied on <span class="CharOverride-6">S. aureus </span>and<span class="CharOverride-6"> P. mirabilis</span> by viable cell counting method. For this, duplicate samples of polymer coupons impregnated with TB dye and silver NPs were taken and 250 µl aliquots of the bacterial suspension of <span class="CharOverride-6">S. aureus</span> and <span class="CharOverride-6">P. mirabilis</span> (10<span class="CharOverride-4">6</span>cfu/ml) were carefully dropped over the surface of each polymer under sterile conditions. Samples were then irradiated with laser light after different time intervals 2 minutes (L<span class="CharOverride-13">2</span>), 5 minutes (L<span class="CharOverride-13">5</span>), 7 minutes (L<span class="CharOverride-13">7</span>) and 10 minutes (L<span class="CharOverride-13">10</span>) along with the controls. 150µl of each bacterial suspension was removed from polymer sample and serially diluted (1:10) in sterile PBS each time (i.e. from control as well as embedded polymer sample) and then plated onto NA plates. All the plates were then incubated at 37<span class="CharOverride-4">o</span>C for 24 hours in a BOD incubator and survivors were enumerated by viable counting. </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-3">Analysis of Leaching Behaviour </p>
			<p class="Body-Text ParaOverride-1">The stability of the impregnated dye in the polymer was tested by analysing the leaching behaviour of the embedded polymer (<a href="#Parekh-J--Chanda-SV--2007"><span class="Hyperlink">Parekh and Chanda, 2007</span></a>). Briefly, square samples of embedded polymer were placed in PBS at 37<span class="CharOverride-4">o</span>C and the UV spectra of PBS solution was recorded at a time interval of 24 h for 3 days to determine the possible release of TB from the embedded samples in PBS solution. The concentration of TB in PBS was then determined on the basis of its absorbance at 660 nm. </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-1--Introduction----">Results and Discussion</p>
		  <p class="Heading-1--Introduction----">&nbsp;</p>
			<p class="Heading-2--History-in-MM- ParaOverride-1">Synthesis and Characterisation of NP and TB Dye Embedded Polymer</p>
			<p class="Body-Text ParaOverride-1">The TB (700ppm) and silver NPs (100ppm) embedded polymer was made by a swell-encapsulation-shrinkage method, which exploits the fact that silicone polymers swell when they are immersed in an organic solvent (<a href="#Lee-JN--Park-C-and-Whiteside-GM--2003"><span class="Hyperlink">Lee et al., 2003</span></a>). This resulted in production of blue coloured polymer which shrunk to its original size and had physically encapsulated TB. The embedded polymer was characterised by UV-analysis at 660nm as the TB solution shows the main absorption peak at 660nm (<a href="#Figure-1-"><span class="Hyperlink">Figure 1</span></a>) (<a href="#Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009a"><span class="Hyperlink">Perni et al., 2009a</span></a>). It can be said from Fig.1 that the polymer embedded with TB only and polymer embedded with TB-silver NPs have a similar profile, confirming the presence of TB in the embedded polymer. Also, it can be observed that least absorption occurred in the polymer embedded with silver NPs alone; this is because the nanoparticles used were below the surface plasmon resonance size limit for nanoparticle colouration (<a href="#Gil-Tomas-J--Tubby-S--Parkin-IP--Narband-N--Dekker-L--Nair-SP--Wilson-M-and-Street-C--2007-"><span class="Hyperlink">Gil-Tomas et al., 2007</span></a>). </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-2--History-in-MM- ParaOverride-1">Evaluation of Anti-microbial Activity of Silver NPs and TB Dye Embedded Polymer</p>
			<p class="Body-Text ParaOverride-1">In order to evaluate the antibacterial activity of silver nanoparticles against <span class="CharOverride-6">S. aureus</span> and <span class="CharOverride-6">P. mirabilis</span>, agar well diffusion method was used (<a href="#Parekh-J--Chanda-SV--2007"><span class="Hyperlink">Parekh and Chanda, 2007</span></a>). The size of zones of inhibition was measured at different concentrations of Silver NPs and 1000 ppm concentration was found most effective against <span class="CharOverride-6">S. aureus</span> and <span class="CharOverride-6">P. mirabilis</span> (<a href="#Table-1-"><span class="Hyperlink">Table 1</span></a>). On decreasing the concentration of silver NPs to 100 ppm, the antibacterial activity was found to be as effective as 1000 ppm concentration of NPs against the studied bacteria. Thus, NP concentration of 100 ppm was used in the further studies. Further, the combined antibacterial activity of polymer samples embedded with toluidine blue (700 ppm) and silver nanoparticles (100 ppm) was assessed by viable cell counting method after irradiation with laser light (<a href="#Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009a"><span class="Hyperlink">Perni et al., 2009a</span></a>; <a href="#Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009b"><span class="Hyperlink">Perni et al., 2009b</span></a>; <a href="#Perni-S--Prokopovich-P--Parkin-IP--Wilsona-M-and-Pratten-J--2010-."><span class="Hyperlink">Perni et al., 2010</span></a>; <a href="#Perni-S--Pratten-J--Wilson-M--2011"><span class="Hyperlink">Perni et al., 2011</span></a>). After irradiation with laser light for different time intervals, viable bacteria were counted and expressed in terms of cfu/ml (as shown in <a href="#Table-2-"><span class="Hyperlink">Table 2</span></a>).<span class="CharOverride-5"> </span><a href="#Figure-2-"><span class="Hyperlink">Figure 2</span></a> shows that the concentration of viable bacteria gradually decreases with the increase in exposure time of laser light. Thus, it can be said that the antibacterial activity of embedded polymer enhances proportionally with the laser irradiation time. </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<div class="pt" > <a href="http://nexusacademicpublishers.com/uploads/figures/20150401190322.png" target="new"><img class="img_display" src="http://nexusacademicpublishers.com/uploads/figures/20150401190322.png" width="80" height="80"></a>
            
            <p class="Figure--and-Table-Heading ParaOverride-1"><span class="CharOverride-5"><a id="Figure-1-"></a>Figure 1: </span><a href="http://nexusacademicpublishers.com/uploads/figures/20150401190322.png">UV-visible spectrum of TB dye and silver NPs embedded polymer at 660nm</a></p>
       </div><br>

			
			<div class="pt" > <a href="http://nexusacademicpublishers.com/uploads/figures/20150401194822.png" target="new"><img class="img_display" src="http://nexusacademicpublishers.com/uploads/figures/20150401194822.png" width="80" height="80"></a>
            
         <p class="Figure--and-Table-Heading ParaOverride-1"><span class="CharOverride-5"><a id="Figure-2-"></a>Figure 2:</span><a href="http://nexusacademicpublishers.com/uploads/figures/20150401194822.png">Concentration of viable bacteria following irradiation with laser light</a></p>
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			<div class="pt" > <a href="http://nexusacademicpublishers.com/uploads/figures/20150401191723.png" target="new"><img class="img_display" src="http://nexusacademicpublishers.com/uploads/figures/20150401191723.png" width="80" height="80"></a>
            
        <p class="Figure--and-Table-Heading ParaOverride-1"><span class="CharOverride-5"><a id="Figure-3-"></a>Figure 3:</span><a href="http://nexusacademicpublishers.com/uploads/figures/20150401191723.png">Absorbance spectrum of TB leaching from polymer samples in PBS and acetone with TB at 700 ppm concentration</a></p>
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			<p class="Figure--and-Table-Heading ParaOverride-1">&nbsp;</p>
			<p class="Figure--and-Table-Heading ParaOverride-1">&nbsp;</p>
		  <p class="Figure--and-Table-Heading ParaOverride-1"><span class="CharOverride-5"><a id="Table-1-"></a>Table 1: </span>Antibacterial activity of silver nanoparticles at different concentrations of bacteria.</p>
			<table width="657" height="140" class="Table-Style-1" id="table-1">
				<colgroup>
					<col class="_idGenTableRowColumn-1" />
					<col class="_idGenTableRowColumn-2" />
					<col class="_idGenTableRowColumn-3" />
				</colgroup>
				<tbody>
					<tr class="_idGenTableRowColumn-4">
						<td rowspan="2">
							<p class="Basic-Paragraph"><span class="CharOverride-15">Concentration of silver nanoparticles</span></p>
						</td>
						<td colspan="2">
							<p class="Basic-Paragraph"><span class="CharOverride-15">Size of zone of inhibition (Diameter, cm)</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-5">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-16">Staphylococcus aureus</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-16">Proteus mirabilis</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-6">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">9.2x10</span><span class="CharOverride-18">-3 </span><span class="CharOverride-17">mol L</span><span class="CharOverride-18">-1 </span><span class="CharOverride-17">(1000ppm)</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">2</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">1</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-7">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">9.2x10</span><span class="CharOverride-18">-4 </span><span class="CharOverride-17">mol L</span><span class="CharOverride-18">-1 </span><span class="CharOverride-17">(100 ppm)</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">1.8</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">0.3</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-8">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">9.2x10</span><span class="CharOverride-18">-5 </span><span class="CharOverride-17">mol L</span><span class="CharOverride-18">-1 </span><span class="CharOverride-17">(10 ppm)</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">0</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">0</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-9">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">9.2x10</span><span class="CharOverride-18">-6 </span><span class="CharOverride-17">mol L</span><span class="CharOverride-18">-1 </span><span class="CharOverride-17">(1 ppm)</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">0</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">0</span></p>
						</td>
					</tr>
				</tbody>
			</table>
			<p class="Figure--and-Table-Heading ParaOverride-1">&nbsp;</p>
			<p class="Figure--and-Table-Heading ParaOverride-1">&nbsp;</p>
		  <p class="Figure--and-Table-Heading ParaOverride-1"><span class="CharOverride-5"><a id="Table-2-"></a>Table 2:</span> Concentration of bacterial suspensions (cfu/ml) in overnight cultures (1:1000) in PBS (std. count) and after laser irradiation for different time intervals</p>
			<table width="657" height="94" class="Table-Style-1" id="table-2">
				<colgroup>
					<col class="_idGenTableRowColumn-10" />
					<col class="_idGenTableRowColumn-11" />
					<col class="_idGenTableRowColumn-12" />
					<col class="_idGenTableRowColumn-13" />
					<col class="_idGenTableRowColumn-13" />
					<col class="_idGenTableRowColumn-14" />
				</colgroup>
				<tbody>
					<tr class="_idGenTableRowColumn-15">
						<td rowspan="2">
							<p class="Basic-Paragraph"><span class="CharOverride-15">Bacteria</span></p>
						</td>
						<td colspan="5">
							<p class="Basic-Paragraph ParaOverride-1"><span class="CharOverride-15">                       cfu/ml</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-5">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">Standard count</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">L</span><span class="CharOverride-19">2</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">L</span><span class="CharOverride-19">5</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">L</span><span class="CharOverride-19">7</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">L</span><span class="CharOverride-19">10</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-4">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-16">Staphylococcus aureus</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">9 ×10</span><span class="CharOverride-18">6</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">33×10</span><span class="CharOverride-18">4</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">24 ×10</span><span class="CharOverride-18">3</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">12 ×10</span><span class="CharOverride-18">2</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">35 ×10</span><span class="CharOverride-18">1</span></p>
						</td>
					</tr>
					<tr class="_idGenTableRowColumn-5">
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-16">Proteus mirabilis</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">88 ×10</span><span class="CharOverride-18">8</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">6 ×10</span><span class="CharOverride-18">6</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">2 ×10</span><span class="CharOverride-18">4</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">7 ×10</span><span class="CharOverride-18">3</span></p>
						</td>
						<td>
							<p class="Basic-Paragraph"><span class="CharOverride-17">3 ×10</span><span class="CharOverride-18">1</span></p>
						</td>
					</tr>
				</tbody>
			</table>
			<p class="Heading-2--History-in-MM- ParaOverride-1">&nbsp;</p>
		  <p class="Heading-2--History-in-MM- ParaOverride-1">Leaching Behaviour of Embedded Components </p>
			<p class="Body-Text">The leaching behaviour of TB dye (700 ppm) from embedded polymer samples was determined in both PBS and acetone using UV-VIS measurements (660 nm) at different time intervals (<a href="#Figure-3-"><span class="Hyperlink">Figure</span><span class="Hyperlink"> 3</span></a>). It can be observed that the leaching was less in polymer containing both TB and NPs in comparison to polymer containing TB only. Also, it can be said from <a href="#Figure-3-"><span class="Hyperlink">Figure 3</span></a> that the leaching of TB was less in PBS as compared to acetone solution; hence the embedded polymer can be efficiently used in aqueous systems.</p>
		  <p class="Body-Text">&nbsp;</p>
			<p class="Heading-1--Introduction----">Conclusion</p>
		  <p class="Heading-1--Introduction----">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">CAIs have been characterized as one of the major health problems worldwide which are difficult to treat because of the growing tolerance to antibiotics of the bacteria involved in infection. Silver nanoparticles have shown promising results as antibacterial agents owing to their free radical generation effect (<a href="#Payne-JL--Ambrosio-AM--2009-"><span class="Hyperlink">Payne and Ambrosio, 2009</span></a>). Also, photodynamic killing of bacteria using photosensitive dyes has been proved to be an alternative to the antibacterial drugs (<a href="#Perni-S--Prokopovich-P--Parkin-IP--Wilsona-M-and-Pratten-J--2010-."><span class="Hyperlink">Perni et al., 2010</span></a>). The bactericidal activity of such dyes can be contributed to the activated oxygen species formed in response to light of certain wavelength. Thus, the present work was carried out to study the synergistic antibacterial effects of silver NPs (in low concentrations) with photosensitive dyes by embedding them in a silicone polymer. The modified silicone polymer showed a very high antibacterial activity against the studied bacteria <span class="CharOverride-6">S. aureus</span> and <span class="CharOverride-6">P. mirabilis. </span>Also, the polymer embedded with TB dye and silver NPs had less leaching effects as compared to the polymer containing TB dye only. Silver coated catheters have been introduced into practice and their usage in a variety of clinical settings indicates their cost-effectiveness in comparison to the costs incurred by catheter related infections (<a href="#Saint-S--Elmore-JG--Sullivan-SD--Emerson-SS--Koepsell-TD--1998"><span class="Hyperlink">Saint et al., 1998</span></a>; <a href="#Karchmer-TB--Giannetta-ET--Muto-CA--Strain-BA--Farr-BM--2000"><span class="Hyperlink">Karchmer et al., 2000</span></a>).</p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">Bacterial UTI is the most common infectious disease of dogs, affecting 14% of all dogs during their lifetime. The incidence of UTI is much higher in older cats as compared to young ones. The risk of urinary tract infections (UTI) among dogs hospitalized in an intensive care unit was observed as 10.3% and bacteria isolates were found common urinary tract pathogens. The UTI can further be lowered by applying properly sterilized catheter but maintenance of sterility becosmes difficult in field condition. The modified silicone polymer showed a very high antibacterial activity and can be potentially used to prevent formation of biofilm on catheter surfaces leading to urinary tract infections as well as other catheter associated infections. The use of this polymer can be potentially exploited for human and animal applications especially in pet animals such as dogs and cats (<a href="#Smarick-SD--Haskins-SC--Aldrich-J--Foley-JE--Kass-PH--Fudge-M--Ling-GV--2004-"><span class="Hyperlink" lang="en-US">Smarick et al., 2004</span></a>).</p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">Therefore, it can be said that such polymers, impregnated with photosensitizer dyes and silver nanoparticles when periodically irradiated with short pulses of laser irradiation through an optical fibre placed in the lumen can provide a new weapon in the fight to reduce catheter related infections by inhibiting biofilm formation and surface colonization. However, further in vivo safety studies may be envisaged for their usage in practical applications. </p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-1--Introduction----">Acknowledgements</p>
		  <p class="Heading-1--Introduction----">&nbsp;</p>
			<p class="Body-Text ParaOverride-1">We acknowledge Kurukshetra University, Kurukshetra for providing all the infrastructure, facilities and support during the course of research work.</p>
		  <p class="Body-Text ParaOverride-1">&nbsp;</p>
			<p class="Heading-1--Introduction----">References</p>
		  <p class="Heading-1--Introduction----">&nbsp;</p>
			
			  <li class="References ParaOverride-2" lang="en-US"><a id="Agarwal-A--Singh-KP--Jain-A--2010"></a>Agarwal A, Singh KP, Jain A (2010). Medical significance and management of staphylococcal biofilm.&#160;FEMS Immunol. Med. Microbiol. 58: 147–160. <a href="http://dx.doi.org/10.1111/j.1574-695X.2009.00601.x"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1111/j.1574-695X.2009.00601.x</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Chambers-HF--DeLeo-FR--2009-."></a>Chambers HF, DeLeo FR (2009). Waves of resistance:&#160;Staphylococcus aureus in the antibiotic era.&#160;Nat. Rev. Microbiol.&#160;7: 629–641. <a href="http://dx.doi.org/10.1038/nrmicro2200"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1038/nrmicro2200</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Chopra-IJ--2007"></a>Chopra IJ (2007). Antimicrob. Chemother<span class="CharOverride-6">. </span>59(4): 587–590. <a href="http://dx.doi.org/10.1093/jac/dkm224"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1093/jac/dkm224</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Catauro-M--Raucci-MG--De-Gaetano-FD--Marotta-A--2004"></a>Catauro M, Raucci MG, De Gaetano FD, Marotta A (2004). Antibacterial and bioactive silver containing Na<span class="CharOverride-13">2</span>O.CaO.2SiO<span class="CharOverride-13">2</span> glass prepared by sol–gel method. J. Mater. Sci. Mater. Med. 15(7): 831 - 837. <a href="http://dx.doi.org/10.1023/B:JMSM.0000032825.51052.00"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1023/B:JMSM.0000032825.51052.00</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Crabtree-JH--Burchette-RJ--Siddiqi-RA--Huen-IT--Handott-LL--Fishman-A--2003"></a>Crabtree JH, Burchette RJ, Siddiqi RA, Huen IT, Handott LL, Fishman A (2003). The efficacy of silver-ion implanted catheters in redu-cing peritoneal dialysis-related infections. Perit. Dial. Int. 23(4): 368-374. </li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Darouiche-RO--Raad-II--1997-"></a>Darouiche RO, Raad II (1997). Prevention of catheter-related infections: the skin. Nutrition. 13(4): S26-S29. <a href="http://dx.doi.org/10.1016/S0899-9007(97)00219-0"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/S0899-9007(97)00219-0</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Donlan-RM--2001-"></a>Donlan RM (2001). Biofilms and device-associated infections.&#160;Emerg. Infect. Dis. 7: 277–281. <a href="http://dx.doi.org/10.3201/eid0702.010226"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.3201/eid0702.010226</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Furno-F--Morley-KS--Wong-B--Sharp-BL--Arnold-PL--Howdle-SM--2004"></a>Furno F, Morley KS, Wong B, Sharp BL, Arnold PL, Howdle SM (2004)<span class="CharOverride-6">. </span>Silver nanoparticles and polymeric medical devices: A new approach to prevention of infection?<span class="CharOverride-6"> </span>J.&#160;Antimicrob. Chemother. 54: 1019-1024. <a href="http://dx.doi.org/10.1093/jac/dkh478"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1093/jac/dkh478</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Gordon-O--Vig-Slenters-T--Brunetto-PS--2010"></a>Gordon O, Vig Slenters T, Brunetto PS (2010). Antimicrob. Agents Chemother. 54(10): 4208–4218. <a href="http://dx.doi.org/10.1093/jac/dkp476"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1093/jac/dkp476</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Gil-Tomas-J--Tubby-S--Parkin-IP--Narband-N--Dekker-L--Nair-SP--Wilson-M-and-Street-C--2007-"></a>Gil-Tomas J, Tubby S, Parkin IP, Narband N, Dekker L, Nair SP, Wilson M and Street C (2007). Lethal photosensitization of <span class="CharOverride-6">Staphylococcus aureus</span> using a toluidine blue O-tiopronin-gold nanoparticle conjugate. J. Mater. Chem. 17: 3739-3746. <a href="http://dx.doi.org/10.1039/b706615e"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1039/b706615e</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Gould-IM--2008-"></a>Gould IM (2008).&#160;Antibiotic policies to control hospital-acquired infections. J. Antimicrob. Chemother. 61: 763–765. <a href="http://dx.doi.org/10.1093/jac/dkn039"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1093/jac/dkn039</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Hall-Stoodley-L--Costerton-JW--Stoodley-P--2004"></a>Hall-Stoodley L, Costerton JW, Stoodley P (2004). Bacterial biofilms: from the natural environment to infectious diseases. Nat. Rev. Microbiol. 2(2):<span class="CharOverride-5"> </span>95-108. <a href="http://dx.doi.org/10.1038/nrmicro821"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1038/nrmicro821</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Hochreiter-W--Knoll-T--Hess-B--2003"></a>Hochreiter W, Knoll T, Hess B (2003). Pathophysiology, diagnosis and conservative therapy of non-calcium kidney calculi]. Ther. Umsch. 60: 89-97. <a href="http://dx.doi.org/10.1024/0040-5930.60.2.89"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1024/0040-5930.60.2.89</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Kim-JS--Kuk-E--Yu-KN--Kim-JH--Park-SJ--Lee-2007"></a>Kim JS, Kuk E, Yu KN, Kim JH, Park SJ, Lee HJ, Kim SH, Park YK, Park YH, Hwang CY, Kim YK, Lee YS, Jeong DH, Cho MH (2007). Antimicrobial effects of silver nanoparticles. Nanomed. Nanotech. Biol. Med. 3:<span class="CharOverride-6"> </span>95–101. <a href="http://dx.doi.org/10.1016/j.nano.2006.12.001"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/j.nano.2006.12.001</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><span class="Hyperlink CharOverride-11"><a id="Karchmer-TB--Giannetta-ET--Muto-CA--Strain-BA--Farr-BM--2000"></a></span>Karchmer TB,&#160;Giannetta ET,&#160;Muto CA,&#160;Strain BA,&#160;Farr BM (2000). A randomized crossover study of silver-coated urinary catheters in hospitalized patients. Arch Intern Med.160(21):3294-8.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Lajcak-M--Heidecke-V--Haude-KH--Rainov-NG--2013-."></a>Lajcak M, Heidecke V, Haude KH, Rainov NG (2013). Infection rates of external ventricular drains are reduced by the use of silver-impregnated catheters. Acta. Neurochir. 155(5): 1637-1639. <a href="http://dx.doi.org/10.1007/s00701-013-1637-9"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1007/s00701-013-1637-9</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Lee-JN--Park-C-and-Whiteside-GM--2003"></a>Lee JN, Park C and Whiteside GM (2003). Solvent compatibility of poly (dimethylsiloxane)-based microfluidic devices. Anal. Chem. 75: 6544-6554. <a href="http://dx.doi.org/10.1021/ac0346712"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1021/ac0346712</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Madeo-M--Davies-D--Johnson-G--Owen-E--Wadsworth-P--Martin-CR--2004"></a>Madeo M, Davies D, Johnson G, Owen E, Wadsworth P, Martin CR (2004). <span class="Hyperlink CharOverride-21">The impact of using silver alloy urinary catheters in reducing the incidence of urinary tract infections in the critical care setting</span>. Br. J. Infect. Contr. 5(1): 21-24. <a href="http://dx.doi.org/10.1177/14690446040050010501"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1177/14690446040050010501</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Maki-D--Mermel-L--1998-."></a>Maki D, Mermel L (1998). Infections due to infusion therapy, in Hospital Infections, Philapelphia, ed. J. Bennett and P. Brachman, Lippincott-Raven. pp. 689.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Pan-cek-A--Kv-tek-L--Prucek-R--Kol-r-M--Vecerov--R--Piz-rov--N--2006-"></a>Panácek A, Kvítek L, Prucek R, Kolár M, Vecerová R, Pizúrová N (2006). J. Phys. Chem. B. 110: 16248–53. <a href="http://dx.doi.org/10.1021/jp063826h"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1021/jp063826h</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Parekh-J--Chanda-SV--2007"></a>Parekh J, Chanda SV (2007). <span class="CharOverride-6">In vitro</span> antimicrobial activity and phytochemical analysis of some Indian medicinal plants. Turk. J. Biol. 31: 53-58.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Payne-JL--Ambrosio-AM--2009-"></a>Payne JL, Ambrosio AM (2009). Evaluation of an antimicrobial silver foam dressing for use with V.A.C. therapy: morphological, mechanical, and antimicrobial properties. J. Biomed.  Biomat. 89: 217–222. <a href="http://dx.doi.org/10.1002/jbm.b.31209"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1002/jbm.b.31209</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009"></a><a id="Perni-S--Piccirillo-C--Pratten-J--Prokopovich-P--Chrzanowski-W--Parkin-IP--Wilson-M--2009a"></a>Perni S, Piccirillo C, Pratten J, Prokopovich P, Chrzanowski W, Parkin IP, Wilson M (2009a). The antimicrobial properties of light-activated polymers containing methylene blue and gold nanoparticles. Biomat. 30: 89-93. <a href="http://dx.doi.org/10.1016/j.biomaterials.2008.09.020"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/j.biomaterials.2008.09.020</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Perni-S--Pratten-J--Wilson-M--2011"></a>Perni S, Pratten J, Wilson M (2011). <span class="Hyperlink CharOverride-21">Antimicrobial Properties of Light-activated Polyurethane Containing Indocyanine Green</span>Journal of Biomaterial Applications. 25: 387-400. </li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Perni-S--Prokopovich-P--Parkin-IP--Wilsona-M-and-Pratten-J--2010-."></a>Perni S, Prokopovich P, Parkin IP, Wilsona M and Pratten J (2010). <span class="Hyperlink CharOverride-21">Prevention of biofilm accumulation on a light-activated antimicrobial catheter material</span>. J. Mater. Chem. 20: 8668–8673. <a href="http://dx.doi.org/10.1039/c0jm01891k"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1039/c0jm01891k</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009"></a><a id="Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009b"></a><a id="Perni-S--Prokopovich-P--Piccirillo-C--Pratten-J--Parkin-IP--Wilson-M--2009b-1"></a>Perni S, Prokopovich P, Piccirillo C, Pratten J, Parkin IP, Wilson M (2009b). <span class="Hyperlink CharOverride-21">Antimicrobial activity of methylene blue and toluidine blue O covalently bound to a modified silicone polymer surface</span>.  J. Mater. Chem. 19: 671. <a href="http://dx.doi.org/10.1039/b905495b"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1039/b905495b</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Roberts-JA--Fussell-EN-and-Kaack-MB--1990-."></a>Roberts JA, Fussell EN and Kaack MB (1990). Bacterial adherence to urethral catheters. J. Urol. 144: 264–269.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Saint-S--Elmore-JG--Sullivan-SD--Emerson-SS--Koepsell-TD--1998"></a>Saint S,<span class="apple-converted-space">&#160;</span>Elmore JG,<span class="apple-converted-space">&#160;</span>Sullivan SD,<span class="apple-converted-space">&#160;</span>Emerson SS,<span class="apple-converted-space">&#160;</span>Koepsell TD (1998). The efficacy of silver alloy-coated urinary catheters in preventing urinary tract infection: a meta-analysis. Am J Med.105(3):236-41.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Sabbuba-NA--Stickler-DJ--Mahenthiralingam-E--Painter-DJ--Parkin-J--Feneley-RC--2004"></a>Sabbuba NA, Stickler DJ, Mahenthiralingam E, Painter DJ, Parkin J, Feneley RC (2004). Genotyping demonstrates that the strains of Proteus mirabilis from bladder stones and catheter encrustations of patients undergoing long-term bladder catheterization are identical. J. Urol. 171: 1925-1928. <a href="http://dx.doi.org/10.1097/01.ju.0000123062.26461.f9"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1097/01.ju.0000123062.26461.f9</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Siddiq-DM--Darouiche-RO--2012"></a>Siddiq DM, Darouiche RO (2012). New strategies to prevent catheter-associated urinary tract infections. Nat. Rev. Urol. 9(6): 305-314. <a href="http://dx.doi.org/10.1038/nrurol.2012.68"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1038/nrurol.2012.68</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Stickler-DJ--Evans-A--Morris-N--Hughes-G--2002"></a>Stickler DJ, Evans A, Morris N, Hughes G (2002). Strategies for the control of catheter encrustation. Int. J. Antimicrob. Ag. 19: 499-506. <a href="http://dx.doi.org/10.1016/S0924-8579(02)00091-2"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/S0924-8579(02)00091-2</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Singh-M--Sing-S--Prasad-S--Gambhir-IS--2008-"></a>Singh M, Sing S, Prasad S, Gambhir IS (2008). <span class="CharOverride-22">Nanotechnology in medicine and antibacterial effect of silver nanoparticles.</span> Digest. J. Nanomater. Biostructures. 3(3): 115–122.</li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Smarick-SD--Haskins-SC--Aldrich-J--Foley-JE--Kass-PH--Fudge-M--Ling-GV--2004-"></a>Smarick SD, Haskins SC, Aldrich J, Foley JE, Kass PH, Fudge M, Ling GV (2004). Incidence of catheter-associated urinary tract infection among dogs in a small animal intensive care unit. J. Am. Vet. Med. Assoc. 224:1936-1940. <a href="http://dx.doi.org/10.2460/javma.2004.224.1936"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.2460/javma.2004.224.1936</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Tenke-P--Jackel-M--Nagy-E--2004"></a>Tenke P, Jackel M, Nagy E (2004). Prevention and Treatment of Catheter-Associated Infections: Myth or Reality? EAU Update Series. 2: 106-115. <a href="http://dx.doi.org/10.1016/j.euus.2004.06.002"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/j.euus.2004.06.002</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Trautner-BW--Darouiche-RO--2004"></a>Trautner BW, Darouiche RO (2004).  Catheter-associated infections: Pathogenesis affects prevention. Arch. Intern. Med. 164(8): 842–50. <a href="http://dx.doi.org/10.1001/archinte.164.8.842"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1001/archinte.164.8.842</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Veenstra-D--Saint-S--Sullivan-SJ--1999-"></a>Veenstra D, Saint S, Sullivan SJ (1999). Am. Med. Assoc. 282: 554–560. <a href="http://dx.doi.org/10.1001/jama.282.6.554"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1001/jama.282.6.554</span></a></li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Walz-JM--Memtsoudis-SG--Heard-SO--2010-."></a>Walz JM, Memtsoudis SG, Heard SO (2010). Prevention of central venous catheter bloodstream infections. J. Intensive Care Med. 25: 131–138. <a href="http://dx.doi.org/10.1177/0885066609358952"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1177/0885066609358952</span></a></li>
		  <li class="References ParaOverride-2" lang="en-US"><a id="Warren-JW--1996"></a>Warren JW (1996). Clinical presentations and epidemiology of urinary tract infections, <span class="CharOverride-6">In </span>H. L. Mobley and J. W. Warren (ed.), Urinary tract infections: molecular pathogenesis and clinical management. ASM Press, Washington, DC. </li>
				<li class="References ParaOverride-2" lang="en-US"><a id="Woodyard-LL--Bowersock-TL--Turek-JJ--McCabe-GP--De-Ford-J--1996-."></a>Woodyard LL, Bowersock TL, Turek JJ, McCabe GP, De Ford J (1996). A comparison of the effects of several silver-treated intravenous catheters on the survival of staphylococci in suspension and their adhesion to the catheter surface. J. Cont. Rel. 40: 23-30. <a href="http://dx.doi.org/10.1016/0168-3659(95)00135-2"><span class="Hyperlink CharOverride-11">http://dx.doi.org/10.1016/0168-3659(95)00135-2</span></a></li>
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