Bactericidal Low Density Polyethylene (LDPE

Materials Science and Engineering C 32 (2012) 263–268

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Bactericidal Low Density Polyethylene (LDPE) urinary catheters: Microbiological characterization and effectiveness I.P.S. Thomé a, V.S. Dagostin a, R. Piletti c, C.T. Pich d, H.G. Riella e, E. Angioletto b, M.A. Fiori b,⁎ a

Programa de Pós-Graduação em Ciências da Saúde - Universidade do Extremo Sul Catarinense - UNESC, Av. Universitária, 1105. Criciúma, SC, Brazil Programa de Pós-Graduação em Ciências e Engenharia de Materiais - Universidade do Extremo Sul Catarinense - UNESC, Av. Universitária, 1105, 88806-000, Criciúma, SC, Brazil Departamento de Engenharia de Alimentos - Universidade do Extremo Sul Catarinense - UNESC, Av. Universitária, 1105, 88806-000, Criciúma, SC, Brazil d Programa de Pós-Graduação em Biotecnologia - Universidade Federal de Santa Catarina - UFSC, Bairro Trindade, 88040-970, Florianópolis, SC, Brazil e Programa de Pós-Graduação em Engenharia Química - Universidade Federal de Santa Catarina - UFSC, Bairro Trindade, 88040-970, Florianópolis, SC, Brazil b c

a r t i c l e

i n f o

Article history: Received 23 July 2010 Received in revised form 11 September 2011 Accepted 18 October 2011 Available online 21 October 2011 Keywords: Urinary catheter Biocidal polymer Bactericidal polymer Biocidal LDPE Triclosan

a b s t r a c t This study investigated the antimicrobial efficacy of Low Density Polyethylene (LDPE) catheters containing triclosan at 0.10 wt.%, 0.50 wt.%, 1.00 wt.% and 1.50 wt.%. The catheters were characterized with the Minimum Inhibitory Concentration (MIC) and Agar Diffusion Tests. They were evaluated in terms of incrustation, biofilm formation and the efficiency of inhibition of bacterial growth after thirty days of lab tests with artificial urine. This research demonstrated the effectiveness of triclosan for inhibiting the growth of microorganisms when incorporated into long-term catheters. The antimicrobial efficiency and genotoxicity results demonstrate that 0.5 wt.% triclosan is the optimal concentration. The genotoxicity test results indicate that triclosan did not result in any significant alterations in the cellular DNA compared to the catheter without triclosan. © 2011 Elsevier B.V. All rights reserved.

1. Introduction Urinary tract infections and incrustation are the two main complications caused by long-term urinary devices, resulting in costs of up to £1 billion a year in Western Europe and a similar amount in North America [1–3,21]. Public health resources could be saved by taking preventive action, such as preventing contamination by microorganisms of various species and the resulting expensive treatment. Within approximately four weeks following insertion, catheters develop an adherent biofilm, mostly on the inside, despite the use of closed drainage systems [4–6]. This biofilm protects the organisms from antimicrobials and from the host's defense mechanisms. Fifty percent of patients with long-term vesicle probes have problems with regular incrustations and catheter blockage. Most of these patients are elderly, as 28% of elderly intensive care unit patients require urinary catheters. The risk of catheter-associated infection ranges from 5.0% to 8.0% of the patients in hospitals every day and reaches 90.0% for patients that undergo prolonged catheterization [6,7]. Patients that need to replace their urinary catheters face a considerable inconvenience and face the risk of injury and contamination by pathogenic microorganisms during this procedure. Furthermore, crystal growth on the surface and other possible sources of device

⁎ Corresponding author. E-mail address: mfi@unesc.net (M.A. Fiori). 0928-4931/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.msec.2011.10.027

obstruction can lead to clinical complications, as the reduction in the flow of urine and blockage of the urinary system increases the levels of toxic substances in the organism, such as urea, and the chances of infection due to premature removal of the catheter [8]. To develop products with long-lasting antimicrobial effectiveness, metallic ions have been incorporated, which results in the slow release of inorganic products into the environment [9]. Many studies have demonstrated the synthesis of polymers and polymeric composite materials with antimicrobial properties. The bactericidal agent principium has been explored and can be effective against gram positive and gram negative bacteria [10–16]. Such bactericidal materials can be used in numerous devices with many different kinds of applications and in the development of products for hospitals and laboratories. Triclosan is a bactericidal substance with low toxicity and a broad range of activities as a bactericidal compound. It is widely used to prevent bacterial infections and is commonly found in dental and other products [23]. The objective of this study was to evaluate the optimal concentration of the antibacterial compound triclosan in vitro and its genotoxic capacity in catheters produced with Low Density Polyethylene (LDPE). The effect of triclosan on the level of incrustation via biofilm formation of crystallized urine on the inner surface of the catheters was also determined. The principal objective of this study was to optimize the bactericidal efficacy of polymeric catheters for future application in patients with urinary tract complications [17].

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2. Materials and methods 2.1. Fabrication of catheters with antimicrobial properties Low Density Polyethylene (LDPE) from Braskem S.A. was used to fabricate the catheters. Triclosan from CIBA S.A. was added to the LDPE at 0.10 wt.%, 0.50 wt.%, 1.00 wt.% and 1.50 wt.%. The catheters had an external diameter of 3.00 mm and an internal diameter of 1.50 mm. The LDPE catheters were produced with an Oryzon-OZ-E-EX-L22 extrusion system with a ratio between the length and the diameter of the screw (L/D) of 17 and a screw diameter (D) of 22 mm. The system had four heating zones with independently controlled temperatures. The processing temperatures were 160 °C for heating zone 1 and 2, 175 °C for heating zone 3 and 180 °C for heating zone 4. The screw velocity was 90 rpm. 2.2. Analysis of the antimicrobial properties of the catheters The following microorganisms (MOs) commonly contribute to urinary tract infections and were used for the antimicrobial tests: Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Salmonella choleraesuis (ATCC 14028), Bacillus subtilis (ATCC 6633), Clostridium sporogenes (ATCC 11437), Enterococcus faecalis (ATCC 29.212) and Staphylococcus aureus (ATCC 25923). All of the MOs were acquired from Foundation André Toselo-SP/Brazil. The agar diffusion and Minimum Inhibitory Concentration (MIC) tests were employed to determine the antimicrobial efficacy of the catheters. The previously listed MOs, with the exception of Enterococcus faecalis, were grown in a Brain Heart Infusion (BHI - OXOID) nutrient liquid with an adjusted concentration of 0.50 on McFarland's scale. The cells were inoculated by streaking on Plate Count Agar (PCA - HIMEDIA) culture plates for bacteria. The samples were prepared in discs with a 0.30 cm diameter, which lacked the triclosan additive or contained the triclosan additive at 0.10 wt.%, 0.80 wt.% and 1.50 wt.%. The plates were incubated at 37.0 °C for 24.0 h. After the incubation, the diameters of the inhibition halos were measured. For the Minimum Inhibitory Concentration (MIC) tests, samples were extracted from catheters without triclosan (white sample) and with triclosan at concentrations of 0.20 wt.%, 0.50 wt.% and 1.00 wt.%. Tube number 1 had a mass of 3.5 × 10 − 3 g, and the mass was decreased by dividing by the square root of three until 2 × 10− 3 g was reached. Six samples were used for each concentration. Then, 100 μL of the MOs Escherichia coli (ATCC 8739), Enterococcus faecalis (ATCC 29.212) and Staphylococcus aureus (ATCC 25923) were inoculated with an adjusted concentration of 0.50 on McFarland's scale into tubes containing 10 mL of BHI. The samples were then set on Pasteur plates in a laboratory incubator for 24 h at 37.0 °C with agitation. The MIC results indicate the minimum inhibitory concentration of biocidal additive in the LDPE required to eliminate the microorganism in a BHI solution. A positive turbidity indicates growth of the microorganism and negative turbidity a lack of growth.

LAUBE [18], and Escherichia coli (ATCC 8739) and Enterococcus faecalis (ATCC 29212) were inoculated into the artificial urine solution. To study the potential incrustation and biofilm formation on the internal surface of the catheters, six 1.0 cm long fragments were analyzed after different exposure times to the urine system; some were not exposed to the urine, and others were exposed for 24 h, 360 h and 720 h. Scanning Electron Microscopy (SEM) was employed to study biofilm formation and incrustation of the inner surface of the catheters. Catheter samples were washed with a saline solution and analyzed in Petri plates following incubation with PCA for 24 h at 37 °C to evaluate the colony growth of the microorganisms. 2.4. Scanning Electron Microscope (SEM) The Scanning Electron Microscope analyses were conducted with a PHILIPS SEM model XL 30 with an energy of 20.00 keV. The presence of incrustation and biofilm deposits was assessed for catheter samples at each concentration of triclosan. 2.5. Genotoxicity test (Comet test) Whole blood was obtained from eight individuals of both genders and ages ranging between 19 and 50 years. The participants were not smokers, drug-users, users of heparinized syringes, or under medical treatment. Blood samples of 200 μL were inserted into the interior of 8.0 cm long catheter fragments without triclosan and into catheters with different concentrations of triclosan: 0.20 wt.%, 0.50 wt.% and 1.0 wt.%. Distilled water was used as a negative control. The samples were incubated at 37 °C for 2 h. The Comet Test was then performed using an adaptation of the procedure described by Bortolotto et al. [19]. The slides containing the samples were washed, dried and analyzed under a NIKON optical microscope at a magnification of 400×. Two slides were examined for each concentration of triclosan, and 50 nuclei were observed per slide. Results were expressed as averages of 8 samples for each concentration. The stained nuclei were classified according to five levels of DNA damage, ranging from undamaged (0) to maximum damage (4). The results were expressed as the DNA damage index (DI) and DNA damage frequency. The DNA damage index (DI) is defined as the sum of the number of cells in each category (0 to 4), multiplied by the damage classification (0–4), and the score varies between 0 (minimum damage) and 400 (maximum damage). The DNA damage frequency (DF) is defined as the number of cells damaged out of 100 cells observed and is expressed as a percentage [19]. These results were statistically analyzed using a 2 criteria ANOVA Newman-Keuls test to compare the results between the concentrations of triclosan and the positive and negative controls. 3. Results and discussion 3.1. Agar diffusion test

2.3. Artificial urine test Two devices with a 5 liter capacity for artificial urine were made. Eight 70 cm long catheters were submerged in artificial urine to characterize the effects of the following triclosan concentrations: 0.20 wt.%, 0.50 wt.% and 1.00 wt.%. The aquarium pump model S180 was used to circulate the artificial urine through the polymeric catheters, which exposed the internal and external surfaces of the polymeric catheters to the artificial urine. Before exposure of the polymeric catheters to the artificial urine systems, the catheters were treated for 20 min with peracetic acid at 2500 ppm to sterilize the surfaces. After catheter sterilization, the samples were treated with artificial urine with the composition reported by

The results of the Agar Diffusion Test are presented in Fig. 1, with inhibition halos expressed as the biocidal area produced by the catheters with different triclosan concentrations [9]. The microbiological results show that the biocidal activity increases with increasing triclosan concentrations for all strains of bacteria tested, with a smaller inhibition halo observed for Pseudomonas aeruginosa. According to Tortora et al., the inhibitory action of triclosan requires the presence of specific enzymes for lipid biosynthetic processes that affect the integrity of the plasma membrane of the microorganisms. Triclosan is especially efficient against gram positive bacteria, but it also works well against fungi and gram negative bacteria. There are some exceptions, such as Pseudomonas aeruginosa, a gram negative


Triclosan Additive

On PCA and in saline culture, triclosan was effective at all three concentrations for up to 15 days for Escherichia coli and up to 30 days for Enterococcus faecalis. Compared with the results for Escherichia coli tested on BHI, which showed no turbidity after 30 days, exposure on PCA resulted in an uncountable number of colonies. This result is likely because the catheter remains immersed in the BHI, allowing the triclosan to reach the culture media; however, for PCA, the saline solution was withdrawn. Another possibility is that triclosan has a bacteriostatic effect at this concentration. The calcium salt composition and the relationship between urinary pH and calcium ion concentration are other important factors that control incrustation in long-term catheter patients.

0.10 wt% 0.80 wt% 1.50 wt%

12

Bactericidal action Area / cm2

10

8

6

4

3.3. Test of catheters with artificial urine

2

sa

li

no gi

a

ru

hi ic

ae as

ch Ps

Sa

eu

lm

do

on

m

on

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er

le ol

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C

co

s ui es ra

og

su s llu ci

Ba

hy ap St

Es

bt

en

ilis

us re au us cc co

es

0

lo

265

Fig. 1. Agar diffusion results showing the bactericidal effect of different triclosan concentrations on the inner surface of the LDPE catheter for different strains of bacteria.

bacterium that is highly resistant to triclosan and many other antibiotics and disinfectants [20]. 3.2. Minimum Inhibitory Concentration - MIC Table 1 shows the presence of turbidity in solutions of different microorganisms incubated with catheters containing different triclosan concentrations. Turbidity is an indicator of bacterial growth in solutions and thus an absence of antibacterial activity. The MIC results demonstrated the absence of turbidity in solutions containing Staphylococcus aureus and Escherichia coli bacteria incubated with catheters with any triclosan additive concentration. These turbidity results show that any percentage of triclosan in LDPE catheters is sufficient to completely eliminate these bacterial species. The MIC results for Enterococcus faecalis show positive turbidity until 0.50 wt.% triclosan is added to the LDPE catheter. Therefore, the microbiological results for the catheters in BHI with Staphylococcus aureus and Escherichia coli indicated that these bacteria have an MIC of 0.20 wt.% triclosan. For Enterococcus faecalis, the MIC was 0.50 wt.% triclosan. For Enterococcus faecalis, the culture was not turbid after 24 h or 15 days with 0.50 wt.% triclosan. This result was not observed after 30 days of incubation of the same bacteria with the blank sample or with 0.20% triclosan. One hypothesis for this behavior is that triclosan loses its bactericidal activity over time, and this effect may be greater at lower concentrations.

Table 1 MIC microbiological results showing the presence of turbidity in solutions containing different microorganisms incubated with catheters containing different triclosan concentrations. Microorganism

Staphylococcus aureus Enterococcus faecalis Escherichia coli

Turbidity 0.20 wt.%

0.50 wt.%

1.00 wt.%

1.50 wt.%

no yes no

no no no

no no no

no no no

The artificial urine appeared to be clear after inoculation with bacteria. After 24 h, the urine turned bright purple. The urine's color became less bright after 15 days, and crystallized salt was observed on the bottom and top surfaces of the catheter. After 30 days, the solution containing Enterococcus faecalis was turbid and had a light pink color, while the solution containing Escherichia coli was turbid and white in color. Escherichia coli solutions incubated with the catheter samples containing no active bactericidal compound became turbid after 24 h. Solutions with BHI-containing catheter samples without the active compound and solutions with catheters containing 0.2 wt.% triclosan became turbid after 30 days. The solutions with BHI-containing catheter samples with 0.5 wt.% and 1.0 wt.% triclosan never became turbid. Therefore, immersion of the catheter in 0.5 wt.% and 1.0 wt.% triclosan results in complete elimination of the Escherichia coli bacteria in the urine solution. Scanning Electron Microscopy (SEM) was used to analyze the presence and composition of crystalline biofilms on the interior and exterior catheter surfaces after they had been submerged in urine containing Escherichia coli bacteria and Enterococcus faecalis. Energy Dispersive Spectroscopy (EDS) of the surface of the catheter with 1.00 wt.% triclosan that was immersed for 24 h in urine containing Escherichia coli showed a substantial increase in the chlorine content on the surface. The increase was approximately 100.0% compared with catheters containing 0.20 wt.% and 0.50 wt.% triclosan. Table 2 shows the chemical elements in the structures of the biofilms and crystals on the surfaces of catheters submerged for different amounts of time in urine containing the Escherichia coli and Enterococcus faecalis bacteria. The qualitative results presented here were obtained by EDS. Independent of the submersion time in the urine solution and the microorganisms used, the white samples on the catheter consisted of carbon and oxygen and crystal and biofilm structures. Chlorine, sodium, calcium and potassium elements were also present in practically all structures. The presence of these chemical elements on the catheter surface and in the crystal structures is indicative of biofilm formation and deposition of a crystal structure from the urine solution onto the catheter. However, these results indicate that biofilm formation increases with decreasing amounts of triclosan and with increasing exposure times. Formation of crystals and biofilms was observed on the inner surface of the LDPE catheters immersed in urine solution for 15 days and 30 days, but 24 h proved to be insufficient for the growth of these structures. Therefore, 15 days was the minimum time needed to grow crystals and biofilms on the catheters containing triclosan for both of the microorganisms studied. The microbiological tests show that catheters containing values above 0.50 wt.% triclosan and immersed for 15 days and 30 days did not develop regions with crystals and biofilms in solutions with either microorganism. For the Escherichia coli bacteria, crystals and biofilms were observed, and biofilms were present for the Enterococcus

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Table 2 EDS results showing qualitative chemical elements present on the inner surface of the LDPE catheters after exposure to artificial urine containing the MOs Escherichia coli and Enterococcus faecalis. Microorganism

Escherichia coli

Submersion time (h)

Triclosan concentration (wt.%)

Regions Observed

24

White 0.20 0.50 1.00 White 0.20 0.50 1.00 White 0.20 0.50 1.00 White 0.20 0.50 1.00 White 0.2 0.5 1.0 White 0.2 0.5 1.0

X X X X X

360

720

Enterococcus faecalis

24

360

720

Catheter

Crystal

X X

Chemical Elements Biofilm

X X

X X X X X X X X X X

. X

X X X X X X X

C

O

X X X X X X X X X X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X X X X X X X X X X

Cl X↓ X X↑ X↑ X X↑ X X

Na

Ca

P

K

X

X

X↑ X↓ X X X

X

X X↑

X

X X X

X↓ X↓ X X↑

X↑ X X

X

X

X↓

X↓

X↓

X X X

X X X↓

X

X↓ X

X↓ X

X↓ X X X X↓

X↓

X↓ X

Subtitles a - Catheter; b - Crystal; c - Biofilm; ↓ - low concentration; ↑ - high concentration.

faecalis. These results provide strong evidence that nucleation and crystallization of the compound and the formation of biofilms does not occur on the inner surface of the LDPE catheters without the presence of the bacteria in the urine solution. In the solutions containing Escherichia coli, crystals were observed on the inner surfaces of the LDPE catheters without triclosan and of the catheters containing 0.2 wt.% triclosan after immersion for 15 days. After 30 days of immersion, crystal formation was observed only in the catheters containing 0.2 wt.% triclosan. In solutions containing Enterococcus faecalis bacteria, the presence of crystals was detected in the catheters without triclosan and in those containing 0.2 wt.% triclosan for times 15 days of immersion, while the formation of biofilms was observed after 30 days. Immersion of the catheters longer 30 days was seen to cause a significant increase of the pH of the artificial urine solutions, with average pH value of 8.40. The pH values influence the crystallization process and the formation of the biofilms. This increase of pH explains the absence of crystals and biofilms in the catheters containing no triclosan after immersion in the urine solution with Escherichia coli for long periods.

For both microorganisms, a total absence of crystals and biofilms was observed for catheters containing 0.5 wt.% and 1.0 wt.% triclosan after immersion times of 15 days and 30 days. Evidently, that percentage of triclosan (above 0.5 wt.%) in the catheters, rather than an increase in pH, is responsible for the lack of crystal and biofilm formation on the inner surface of these samples. The results show that there was no formation of crystals and biofilms with an immersion time of 24 h, but the presence of chlorine, sodium, calcium and potassium was detected on the inner surface of the LDPE catheters, in addition to carbon and oxygen. Therefore, for this length of immersion, adsorption of the species present in the artificial urine solution and an increase in the triclosan concentration on the surface can occur. The increase in the concentration of chlorine species on the catheter is expected because triclosan contains chlorine in its aromatic structure [22]. Thus, the increase in the percentage of chlorine may be due to an increase in the triclosan content inside of the catheters, resulting in an increase in the bactericidal action. Under virtually all conditions, samples with immersion times exceeding 24 h were observed to have sodium, potassium and calcium

Fig. 2. Scanning Electron Microscopy (SEM) images of the internal surface of a catheter produced with 0.2 wt.% triclosan and submerged in urine containing Escherichia coli bacteria. (a) After submersion for 15 days and (b) after submersion for 30 days.


40,00 35,00

Catheter sample

Damage index average

Triclosan 0.2 wt%

26.75 ± 5.85

Triclosan 0.5 wt%

22.37 ± 5.68

Triclosan 1.0 wt%

28.25 ± 12.17

Without triclosan (White sample) H2O

22.50 ± 7.52

18.00 ± 4.21

DNA damage index

30,00 25,00 20,00 15,00 10,00 5,00

(W hi

te

H 2O

sa m pl

e)

w t% 1. 0 sa n W

ith

ou

tt ric lo

sa n

Tr ic lo

Tr ic lo

Tr ic lo

sa n

sa n

0. 2

0. 5

w t%

w t%

0,00

Fig. 3. Genotoxicity assay: DNA damage index for blood samples exposed to different triclosan concentrations in the catheters. Samples without triclosan and water were used as negative controls.

present on their inner surfaces. The presence of ideal conditions for crystallization and biofilm formation is probably due to the similar ionic radii and oxidation numbers of these elements. However, calcium was present only at immersion times above 24 h because its ionic radius is larger and its oxidation number is (II), while the oxidation number of potassium and sodium is (I). So it is expected that the reduction of calcium and its accommodation in the crystal structure will require a greater amount of time.

Catheter sample Average of frequency Triclosan 0.2 wt% 24.12 ± 4.45 Triclosan 0.5 wt% 19.12 ± 4.85 Triclosan 1.0 wt% 27.12 ± 9.42 Without triclosan (White sample) 21.12 ± 6.71 H2O 16.75 ± 4.06

40,00

35,00

DNA damage frequency

30,00

25,00

267

The sodium species were found in the greatest quantity on the catheter because sodium has the smallest ionic radius. Phosphorus is rarely observed in the crystals and biofilms because its ionic radius is very large, and its oxidation number is (V), which is higher than any of the other elements present in the urine. This lowers the probability of deposition of phosphorus onto the crystal structures and biofilms on the inner surface of the LDPE catheters. In addition to the presence of crystals and biofilms, the EDS results also showed the presence of oxidized species on the inner surface. Oxygen and carbon were present under all conditions and originated either from the organic molecules of the LDPE polymer or from the triclosan and its oxidized species. Thus, even without crystals and biofilms, the presence of species present in the urine was observed in the oxidized state on the surface of the catheter. Overall, increases in the concentration of triclosan hinder the formation of crystals and biofilms on the surface of the catheters. Higher concentrations of triclosan decrease the quantities of sodium, potassium and calcium that are deposited on the surface of the catheter, as these species are the constituents of the crystals and biofilms. SEM conducted on the inner portion the catheters containing 0.2 wt.% triclosan after 30 days of immersion revealed the presence of crystalline structures, which contribute to obstructions in longterm catheters. Fig. 2 shows the SEM images of the internal surface of a catheter containing 0.2 wt.% triclosan after submersion in urine containing Escherichia coli. The images show that a crystalline biofilm had formed on the surface. Fig. 2a shows the formation of a biofilm and crystalline grains on the catheter surface after 15 days in the urine solution. The biofilm is uniform, and the grains appear to be stalactite. Fig. 2b shows the details of the grains on the catheter surface after 30 days in the urine solution. The images show the nucleation of various small grains and the presence of large crystalline grains. 3.4. Genotoxicity test (Comet test) Figs. 3 and 4 present the results of the genotoxicity tests along with the index and frequency data for catheters with or without the active bactericidal compound (white sample) and with incubation in water as a negative control. The DNA damage index values of the catheters containing triclosan were not significantly different from that of the negative control. Catheters containing triclosan at 1.0 wt.% had a significantly greater frequency of DNA damage than water, with a p-value of less than 0.05. However, this value was not significantly different from that of the catheter without the active compound. An ANOVA analysis of the genotoxicity results indicated that the catheters containing triclosan as a bactericidal active compound did not significantly alter blood cell DNA.

20,00

4. Conclusions 15,00

10,00

5,00

m

2O

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e) pl

t% w 0

te

1. n

(W

hi

sa lo ic W

ith

ou t

tri

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n

Tr

lo sa n ic Tr

Tr

ic

lo

sa

n

0.

0.

2

5

w

w

t%

t%

0,00

The polymeric catheter produced with Low Density Polyethylene (LDPE) presented good biocidal efficacy. A triclosan concentration of 0.50 wt.% is sufficient to impart antimicrobial properties to the catheter. Biofilm formation increased with decreasing triclosan concentrations and with increasing exposure times, and the presence of microorganisms in the artificial urine increased the pH over 30 days, and the increased pH contributed to incrustation and biofilm formation. Therefore, catheters containing triclosan have the potential to prevent urinary infections associated with long-term catheter use.

Fig. 4. Genotoxicity assay: DNA damage frequency for blood samples exposed to different triclosan concentrations in the catheters. Samples without triclosan and water were used as negative controls.

Acknowledgements The authors wish to thank the Laboratory of Biomaterials and Antimicrobial Materials – LADEBIMA and the Laboratory of Advanced

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Materials and Polymer Processing – LMPP of the UNESC and Biotechnology Laboratory of the Biological Center of the Universidade Federal de Santa Catarina, UFSC. References [1] [2] [3] [4] [5] [6] [7] [8] [9]

[10]

R. Plowman, et al., J. Hosp. Infect. 48 (2001) 33–42. Kohler, J. Ockmore, R.C.L. Feneley, Br. J. Urol. 77 (1996) 347–351. N. Slade, W.A. Gillespie, Chichester, Wiley, 1985, pp. 11–35. C.M. Kunin, Detection, prevention and management of urinary tract infections, 4. ed, Lea and Ferbiger, Philadelphia, 1987, pp. 5–6. A.B. Mulhall, R.G. Chapman, R.A. Crow, J. Hosp. Infect. 11 (1988) 253–262. C. Kunin, Int. J. Antimicrob. Agents 28S (2006) S78–S81. L. Jonesa, A.D. Russell, Z. Caliskana, D.J. Sticklera, Eur. Urol. 48 (2005) 838–845. P. Tenke, B. Kovacs, M. Jackel, E. Nagy, World J. Urol. 24 (2006) 13–20. Fiori, M.A.; Paula, Marcos Marques da Silva; Bernardini, Adriano Michael; Riella, Humberto Gracher; Angioletto, Elídio. Bactericide glasses developed by Na+/Ag+ ionic exchange. Materials Science & Engineering. C, Biomimetic Materials, Sensors and Systems, 2009. 29: p. 1569–1573. M.M.S. Paula, C. Franco, M. Baldin, L. Rodrigues, T. Barichello, G. Savi, L. Bellato, M.A. Fiori, Silva, Luciano., Sensors and Systems 29 (2009) 647–650.

[11] M.A. Fiori, M.M.S. Paula, E. Angioletto, M.F. Santos, H.G. Riella, M.G. Quadri, Mater. Sci. Forum 591 (2008) 362–367. [12] M.A. Fiori, M.M.S. Paula, Luciano Silva, E. Angioletto, E.C. Santos, J. Fiori Jr., H.G. Riella, Brazilian Journal of Materials Science and Engineering 8–10 (2008) 21–28. [13] G.M. Gadd, FEMS Microbiol. Lett. 100 (1992) 197–204. [14] Sugiura, K. et al. Microbicides, United States Patent. 1994. 5 : p. 238, 296. [15] Prat, A. S., Smith, P. R., Antimicrobial Compositions Consisting of Metallic Silver Combined With Titanium Oxide or Tantalum Oxide, United States Patent, 1989. 4: p. 223, 849. [16] Oku, T. et al. Anti-bacterial and Anti-fungal Glaze Composition for Ceramic Products, United States: Patent 5, 1998. p. 641, 807. [17] S.M. Jacobsen, D.J. Stickler, H.L.T. Mobley, M.E. Shirtliff, Clin. Microbiol. Rev. 21( (1) (2008) 26–59. [18] Norbet Laube, et al., Clin. Chem. Lab. Med. 39 (3) (2001) 218–222 New York. [19] T. Bortolotto, J.B. Bertoldo, F.Z. Silveira, T.M. Defaveri, J. Silvano, C.T. Pich, Environ. Toxicol. Pharmacol. 28 (2009) 288–292. [20] G.J. Tortora, Microbiologia, 8. ed. Artmed, Porto Alegre, 2005. [21] S. Choong, et al., Catheter associated urinary tract infection and encrustation. Institute of Urology and Nephrology, Elsevier Science B.V, London, UK, 2001. [22] M.A. Fiori, M.M.S. Paula, L. Silva, M.F. Santos, E. Angioletto, H.G. Riella, M.G.N. Quadri, Polymer Processing XXIV (2009) 414–420. [23] T.E. Bolden, J.J. Zambon, J. Clin. Dent. 4 (1992) 125–131.