Article pubs.acs.org/IECR
Synthesis of New Biobased Antibacterial Methacrylates Derived from Tannic Acid and Their Application in UV-Cured Coatings Ren Liu,* Junchao Zheng, Ruixi Guo, Jing Luo, Yan Yuan, and Xiaoya Liu The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, China ABSTRACT: A series of biobased UV-curable antibacterial resins were synthesized through modifying tannic acid (TA) with varied amount of glycidyl methacrylate (GMA). The obtained TA-based methacrylates exhibited good film-forming property and can be cross-linked under UV irradiation. Thus, antibacterial functionalities can be tethered in the coating matrix, eliminating the loss of antibacterial ingredients. The antibacterial properties of resins and corresponding coatings against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were tested. The resins with high content of phenolic hydroxyl groups retained strong antibacterial ability while the ones with a relatively low content of phenolic hydroxyl groups did not, which indicated that the antimicrobial effects of TA greatly depended on the content of phenolic hydroxyl groups. The applications of UV-curable antibacterial resins in coatings were also studied. The cured coatings of TA-G5 resins with the highest content of phenolic hydroxyl groups exhibited the highest antibacterial activity with 5 log reduction. The basic properties of UV-cured coatings were also fully characterized, and the results demonstrated that the novel UV-curable resins had potential applications in UV-curable antibacterial coatings. groups.23 Through modification with photosensitive monomer, antibacterial TA-based methacrylates can be cross-linked, and therefore, the antibacterial functionalities can be tethered into the coating matrix after UV irradiation. UV curing is a wellknown, environmentally friendly, energy-saving, and highefficient coating technology. Utilization of biobased antibacterial materials in UV-curable formulations provides a promising “green+green+healthy” solution to stricter environmental regulations, higher raw material costs, and increasing health concern. In this paper, a series of novel UV-curable biobased antibacterial methacrylates was designed and straightforwardly synthesized. The antibacterial ability of TA-based methacrylates was investigated through zone of inhibition tests. Furthermore, the applications of the UV-curable antibacterial resins in coatings were also studied. After UV irradiation, coatings based on TA exhibited good hardness, adhesion, chemical resistance, and various antibacterial ability. These results demonstrate that TA-based methacrylates with good antibacterial ability have great potential application in UV-curable antibacterial coatings, such as food packaging, medical devices, and other end-use sectors regarding infection and contamination.
1. INTRODUCTION Tannic acid (TA) is a kind of natural polyphenol that is commonly found in high herbaceous and woody plants.1 In addition to be used in leather processing industries and wastewater treatment, TA has been reported to be bacteriostatic or bactericidal against many kinds of bacteria such as Staphylococcus aureus,2,3 Escherichia coli,3,4 Helicobacter pylori5 and even has an inhibitory effect on tumor cells,6 HIV,7 and the influenza virus.8,9 Nowadays, due to the increasing health concern of people in everyday life, further research of TA in biomedical applications is highly expected. To the best of our knowledge, antibacterial TA is always used as its original powder form that has greatly limited its further application, especially in healthcare applications. In the healthcare realm, the growth and accumulation of harmful bacteria on the surface of medical devices and the infection caused has been a long-term problem affecting people’s health. Modifying the surface of a medical device with antibacterial coatings is an effective antibacterial method. The most common and straightforward way to prepare bactericide materials is direct loading with antimicrobial agents such as antibiotics,10 silver ions,11,12 phenols,13−15 and peptides.16,17 The antimicrobial effect is achieved based on the release principle of gradually leaching biocides into surroundings. However, such approach has some fundamental flaws such as the loss of antibacterial ingredients and the undesirable release of some toxic biocides into the environment.18 Alternatively, antibacterial materials can be obtained through chemically tethering bactericidal functionalities or biocides into the matrix,19−22 eliminating the issues associated with the release of biocides. Therefore, making antimicrobial coatings by immobilizing nontoxic biocides or functionalities is one of the most promising approaches. Naturally, the antibacterial mechanism of TA should not be dependent on phenol mobility but on the phenolic hydroxyl © 2014 American Chemical Society
2. EXPERIMENTAL SECTION 2.1. Materials. TA (99%) and glycidyl methacrylate (GMA, 98%) were purchased from Aladdin (Shanghai, China) without further purification. Triphenylphosphine (TPP), methoxyphenol (MEHQ), anhydrous ethanol, and butyl acetate were purchased from Shanghai Chemical Reagent Co., Ltd. (Shanghai, China) and used as received. TrimethylbenoyldiReceived: Revised: Accepted: Published: 10835
February 17, 2014 June 2, 2014 June 9, 2014 June 9, 2014 dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
Industrial & Engineering Chemistry Research
Article
Figure 1. Synthetic route of antimicrobial UV-curable TA-Gx resins.
The liquid coatings were cast on aluminum panels for basic properties tests or PVC substrates for antimicrobial tests with a drawdown block to form a thin film with about 30 μm thick, followed by UV curing using a Fusion LC6B benchtop conveyor with an F300 UVA lamp (UVA intensity of 120 mW/cm2 measured using a UV-int140 from DESIGN Germany) in air. The general curing protocol was three passes through the lamp at the conveyer belt speed of 5 m/min. The coatings were tested after being conditioned in ambient conditions for at least 48 h. 2.5. Characterization. Thickness were measured using a Qnix 1500 thickness gauge, and three measurements were repeated. Gloss measurements were obtained using a BYKGardner micro-TRI-gloss meter, and the mean of these measurements was recorded. Pencil hardness was determined by pushing the pencil with different hardness from the film to the substrate with moderate pressure and determining whether a scratch had been produced. The softest pencil that does not leave a scratch was taken to be the hardness. Pendulum hardness of the coatings was measured following ASTM D 4366. The hardness test results are reported in seconds (s). Methyl ethyl ketone (MEK) double rubs test was performed according to ASTM D 5402 to assess the chemical resistance and curing degree. A 1 kg hammer with three layers of cheesecloth wrapped around the hammerhead was soaked in MEK. The hammer head was rewetted with MEK after 30−50 double rubs. Once the coating was damaged, the number of double rubs was recorded. Crosshatch adhesion was performed according to ASTM D3359. A 10 × 10 grid was cut into the cast coating with a razor blade, and the percentage of remaining squares was recorded after removal with adhesive tape. Two trials were taken to obtain the averaged results. Surface hydrophilicity of prepared coatings was determined by measurement of water droplet contact angle. Three different water droplets (1.5 μL) were deposited on the surface at different positions and a CCD camera imaged the droplets. Automated image analysis was used to determine the contact angles and record the average contact angle values. 2.6. Photopolymerization of TA-Gx. Real-time IR (RTIR) was used to determine the conversion of double
phenyl phosphine oxide (TPO) was supplied by Jiangsu Kuangshun Co., Ltd. (Wuxi, China) and used as a deep curing agent. Photoinitiator Irgacure 184 (1-hydroxycyclohexyl phenyl ketone) was obtained from BASF chemicals. 2.2. Synthesis of Antimicrobial UV-Curable TA-Gx Resins. TA-Gx resins (molar ratio of TA/GMA was 1/x, where x = 5, 10, 15, 20, 25) were carried out in a four-necked roundbottom flask equipped with an addition funnel, a condenser, a mechanical stirrer, a thermometer, and nitrogen inlet/outlet tubes. A typical synthesis procedure of TA-G5 was as follows: 17.00 g (0.01 mol) of TA, 0.36 g (1.5 wt %) of TPP, 0.03 g (0.1 wt %) of MEHQ, and 40 mL of mixed solvent (V(anhydrous ethanol)/V(butyl acetate) = 1/2) were placed into a 250 mL round-bottom flask, and then, 7.11 g (0.05 mol) of GMA was added dropwise to the mixture. The reaction mixture was stirred at 95 ∼ 100 °C until the epoxy value approached to zero with epoxy value titration. The synthetic route is shown in Figure 1. 2.3. Characterization of Antimicrobial UV-Curable TAGx Resins. A FTLA2000-104 FTIR spectrometer from Thermo Scientific was used for the Fourier transform IR (FTIR) measurements. Sample aliquots were taken and coated on a potassium bromide salt plate. 1H NMR spectra of the TAGx were recorded on a Bruker DMX500 MHz spectrometer (400 MHz) at 25 °C with DMSO as the solvent. The molecular weights and molecular weight distribution of TA-Gx were measured by gel permeation chromatography (GPC) with a differential refractive index and a photodiode array detector, using tetrahydrofuran (THF) as an eluent (elution rate, 1.0 mL/min) and polystyrene (PS) standards for calibration. Epoxy value of resins was determined by titration with hydrogen bromide (HBr) according to ASTM D1652, and the end point of the titration was determined by a Mettler Toledo T70 potentiometric titrator. The viscosity was measured by a RVDV-III rheometer with CP-52 rotor and shear rate of 4 s−1. 2.4. Preparation of UV-Curable Formulations and Coatings. The UV-curable coating formulations were prepared by mixing TA-Gx resins with Irgacure 184 (3 wt %) and TPO (0.5 wt %). Gentle heating was used to help dissolution of the photoinitiators when necessary. 10836
dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
Industrial & Engineering Chemistry Research
Article
bonds. The coating formulation was coated on a KBr window and then irradiated with an EfosLite mercury vapor curing lamp equipped with a fiber optic light guide for 300 s at intensity of 40 mW/cm2. The light intensity on the surface of samples was detected by a visible light radiometer (400−1000 nm, Beijing Normal University, China). All the experiments were performed in air. The decrease in the peak area of the methacrylate peak at 810 cm−1 was monitored with a resolution of 4 cm−1 to characterize the photopolymerization. For each sample, the series of RTIR runs were repeated three times. 2.7. Antimicrobial Test Procedure. Cultures of E. coli and S. aureus were grown aerobically for 10 h at 37 °C in sterile Luria−Bertani (LB) broth (normal rich growth medium: NaCl, 10 g/L; yeast extract, 5 g/L; tryptone, 10 g/L). These active growing cultures were centrifuged and resuspended in a 0.5% saline solution. The bacteria solutions were diluted in saline (8.5 g/L), and the concentrations were evaluated quantitatively by measuring OD600nm. 2.7.1. Zone of Inhibition Test. The filter paper disc agar method was used for this study. The plates were inoculated at a level of 106 cfu/mL bacteria. The sterilized filter paper discs (10 mm diameter) were thoroughly moistened with different concentrations of TA-Gx resin solutions (5% ∼ 40 wt %% in DMSO) and then placed on agar plates. The antibacterial activity of TA-Gx resins was demonstrated by a clear zone of inhibition around the disc. The zone of inhibition was measured with the help of Vernier callipers after 24 h of incubation at 37 °C, and an average of three replicates was reported. 2.7.2. Antimicrobial Activity Determination of TA-Gx Coatings. The bacterial log reduction test followed is similar to the standard antimicrobial susceptibility test protocols like ISO 22196 and JIS Z 2801. Obtained bacterial solutions were distributed over 12-well cell plates containing 1.5 mm × 1.5 mm coating or PVC substrate, except for the control well without coating.24 Incubation for 24 h at 37 °C was done without shaking the cell plates. Although plates were not shaken in order to avoid wrinkling and rolling up of the sample films, full contact between bacterial solution and prepared coatings was ensured by adding only 1.5 mL of bacterial solution on 1.5 mm × 1.5 mm samples. After 24 h incubation, a dilution series of each treatment was made, and 100 μL of 3 dilutions was plated on sterile LB agar (LB broth+agar, 20 g/ L). After 24 h, the number of colonies on each plate was determined to get the corresponding concentration of living bacteria. In order to show the antibacterial activity of coatings more visually, the aerosol method for determining surface antimicrobial character was done. An aqueous suspension of E. coli and S. aureus (104−105 cfu/mL) was casted onto the prepared slides by aerosol spraying. After air-drying for 2 min, the glass slides were cultivated overnight at 37 °C under autoclaved growth agar. Then, the grown bacterial colonies were inspected and counted to evaluate the antibacterial performances.
Figure 2. FTIR spectra of TA-Gx UV-curable resins.
cm−1) appeared in all curves. A comparison for the characteristic absorption bands of CC indicated that the content of CC double bonds of TA-Gx expectedly increased with the increasing of GMA. The 1H NMR spectra for TA-Gx resins are shown in Figure 3. 1H NMR spectra verified that methacrylate double bonds
Figure 3. 1H NMR spectra of TA-Gx UV-curable resins.
were effectively incorporated into the TA. The grafting ratio was calculated from the peak area ratio of the peaks at 6.7−7.2 ppm, which corresponded to the proton on the benzene ring, and the peaks at 5.6 and 6.1 ppm, which corresponded to the proton on the carbon−carbon double bond. The average grafting quantities of CC on each molecule were calculated as 5.6 (TA-G5), 11.6 (TA-G10), 16.1 (TA-G15), 19.7 (TAG20), and 23.3 (TA-G25). 3.2. Characterization of UV-Curable Resins. The synthesized TA-Gx resins are brown, highly viscous liquids. Unlike TA, which is powder and has poor solubility in many organic solvents such as chloroform and acetone, TA-Gx resins exhibited a fine film-forming property and better solubility in many organic solvents. In addition, the modification imparted a TA UV-curable property to obtain high biobased content UVcured coatings. Table 1 showed the physics properties of TAGx resins. Biobased content of resins were relatively high, ranging from 31.8% to 65.9%. The viscosity decreased sharply with the increasing content of GMA. This phenomenon can be attributed to the introduction of soft segments and the weaker hydrogen-bonding interaction between alcoholic hydroxyl
3. RESULTS AND DISCUSSION 3.1. Synthesis of TA-Gx Resins. Methacrylated TA resins were synthesized by reacting TA with different amounts of GMA. Resins were noted by TA-Gx, where x stood for the molar ratio of GMA/TA (5, 10, 15, 20 or 25). Figure 2 showed the FTIR spectra for TA-Gx resins. The characteristic absorption bands for CH3 and CH2 (3000−2850 cm−1), CO (1750 cm−1), and CC (1640 10837
dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
Industrial & Engineering Chemistry Research
Article
Table 1. Properties of TA-Gx Resins GPC
a
resin
biocontent (%BRC)
viscosity(mPa·S) at 30 °C
methacrylate functionalitya
methacrylate equivalent weighta(g/mol)
Mn × 10−3
PDI
TA-G5 TA-G10 TA-G15 TA-G20 TA-G25
65.9 48.3 40.3 35.5 31.8
39837.16 31018.24 20588.15 9392.83 5473.64
5.6 11.6 16.1 19.7 23.3
445.99 288.86 247.86 228.56 215.21
1.2 1.5 1.8 2.1 2.3
1.03 1.02 1.03 1.03 1.04
The values were calculated from 1H NMR spectra.
agent to inhibit the growth of microorganisms. During the incubation period, the plated bacteria cannot grow where antimicrobial agents exist. Table 2 indicated that some of the
groups of TA-Gx resins than phenolic hydroxyl groups of TA. The molecular weights of the resins were also shown in Table 1. However, it should be recognized that molecular separation via GPC is based on hydrodynamic volume compared to polystyrene standards. GPC is not a reliable quantitative measurement of molecular weight for highly branched molecules such as TA-Gx resins. Nevertheless, the GPC molecular weight values can provide insight into the relative molecular size of the compounds.25 3.3. Double Bond Conversion of UV-Cured Films. In the RTIR experiments, the CH out-of-plane band at 810 cm−1 was monitored to study the conversion of methacrylate. The degree of conversion can be determined by eq 1:
Table 2. Antibacterial Activity Measured by Zone of Inhibition Testa sample
conc of TA-Gx Resins (wt % in DMSO) 40%
TAG5
TAG10
⎧ [(A)810 ]0 − [(A)810 ]t ⎫ ⎬ × 100 degree of conversion = ⎨ [(A)810 ]0 ⎩ ⎭
TAG15
where [(A)810]0 denotes the absorption peak area before UV exposure while [(A)810]t is the absorption peak area after UV exposure. The corresponding curves are shown in Figure 4. The
17.5 ± 1.2
16 ± 0.8
S.
19.5 ± 0.0
15 ± 0.4
14 ± 0.0
13.5 ± 0.1
16 ± 1.1
15 ± 0.6
14.5 ± 0.8
13 ± 0.3
13.5 ± 0.7
12.5 ± 0.0
12 ± 0.0
12 ± 0.0
11 ± 0.4
10.5 ± 0.8
0
0
11.5 ± 0.0
11 ± 0.0
0
0
11 ± 0.9
10.5 ± 0.0
0
0
11.5 ± 0.0
11 ± 0.0
0
0
0
0
0
0
0
0
0
0
aureus E. coli aureus E. coli aureus E. coli S.
TAG25
5%
18 ± 1.0
S. TAG20
10%
19 ± 1.6
S.
(1)
20%
E. coli
aureus E. coli S. aureus
Units in mm. Number after ± sign corresponds to the standard deviation.
a
TA-Gx resins still retained antibacterial ability to both E. coli and S. aureus, especially TA-G5 and TA-G10. With a higher concentration of resins, the zone of inhibition was larger. When the concentration was the same, resins with more phenolic hydroxyl groups showed stronger antibacterial activity to both E. coli and S. aureus. The results demonstrated that the phenolic hydroxyl groups play an important role in antibacterial activity. 3.5. Properties of UV-Cured Coatings. Table 3 showed the basic properties of UV-cured TA-Gx coatings. The thickness of the cured coatings was almost the same, about 20 μm. The gloss value was relatively high, from 114 to 121. The pendulum hardness of the coatings increased in an order of TA-G25 > TA-G20 > TA-G15 > TA-G10 > TA-G5. The same trend was observed for pencil hardness. This kind of trend was caused by the different content of methacrylate functionality. In the UV-curing system, generally, the higher methacrylate functionality means higher hardness. All the coatings showed excellent adhesion to aluminum panels, except for TA-G25. The good adhesion may attribute to the hydroxyl groups in the structure that can react with metal ions to form TA−metal complexes.28 The hydrophilicity of TA-Gx coatings was evaluated by water contact angle measurements. The results
Figure 4. Photopolymerization double bond conversions for TA-Gx UV-curable resins.
conversions of all TA-Gx formulations were higher than 80% except TA-G5 coating. The relatively low conversion of TA-G5 was due to the low content of methacrylate groups. On the other hand, higher methacrylate functionality does not always lead to higher double bond conversion. The formulation with too high methacrylate functionality would let vitrification emerge earlier that decreases the double bond conversion.26,27 Therefore, TA-G25 containing the highest content of methacrylate groups did not exhibited the highest double bond conversion. 3.4. Antibacterial Activity of TA-Gx Resins Measured by Zone of Inhibition Test. The zone of inhibition test is a fast, qualitative means to measure the ability of an antimicrobial 10838
dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
Industrial & Engineering Chemistry Research
Article
Table 3. Properties of Coatings sample TA-G5 TA-G10 TA-G15 TA-G20 TA-G25 a
thickness (μm)a gloss (60°)a 20.1 18.5 20.6 19.6 19.3
± ± ± ± ±
4.6 2.7 3.0 2.0 0.5
114 115 117 119 121
± ± ± ± ±
1.5 3.0 1.5 3.1 1.0
pencil hardness
pendulum hardness (s)a cross-hatch adhesion
2H 3H 3H 4H 4H
75 122 125 130 131
± ± ± ± ±
4 0 3 2 0
water contact angle (deg)a MEK double rubsa
0 0 0 0 1
21.5 39.1 55.5 56.7 68.6
± ± ± ± ±
0.5 1.0 1.2 0.8 0.4
50 360 422 445 510
± ± ± ± ±
3 5 10 12 21
Three measurements were repeated.
showed all the coatings were hydrophilic and hydrophilicity of TA-G5 is the best. TA-Gx coatings had good chemical resistance indicated by MEK double rub values except for the TA-G5 coating. Chemical resistance property was greatly influenced by the cross-linking density of the coatings. The relatively poor chemical resistance property of the TA-G5 coating was due to the lowest double bond content of the TAG5 resin. 3.6. Antimicrobial Activity Determination of TA-Gx Coatings. The antimicrobial activity of the prepared films was examined for both Gram-positive S. aureus and Gram-negative E. coli types of bacterial species after 24 h incubation. As listed in Table 4, the TA-G5 coating exhibited excellent antimicrobial Figure 5. Photographs of bacteria colonies grown on glass slides: (a) coated with TA-G5 against E. coli; (b) coated with TA-G20 against E. coli; (c) coated with TA-G5 against S. aureus; (d) coated with TA-G20 against S. aureus.
Table 4. Bacterial log10 Reduction after 24 h Incubation of 105 Bacteria with 1.5 mm × 1.5 mm Prepared Films bacterial log10 reduction sample code
residual phenolic OH per molecule(theory)
E. coli
S. aureus
TA-G5 TA-G10 TA-G15 TA-G20 TA-G25 PVC control
20 15 10 5 0 − −
5 log 0.7 log 0 log 0 log 0 log 0 log 0 log
5 log 0.9 log 0.5 log 0 log 0 log 0 log 0 log
4. CONCLUSION TA, an abundant renewable raw material, was used for UVcurable coatings with antibacterial ability. After modification with GMA, TA-based methacrylates were prepared as a viscous liquid and showed good film-forming properties. The methacrylate functionalities had great influence on the coating properties such as hardness, MEK double rubs, and antibacterial activity. The higher functionality gave rise to higher hardness and greater chemical resistance. However, the antibacterial activity of coatings decreased with the increased number of methacrylate functionality. The reduction was caused by the decreased number of phenolic hydroxyl groups with antibacterial property. The optimized coatings with good antibacterial activity and acceptable physical properties showed promising application prospects in antibacterial coatings.
activity with a 5 log reduction of both bacterial species. The obtained antimicrobial activity of the TA-G5 coating is comparable to that of other antibacterial coatings using the same antimicrobial test procedure.29,30 The proposed antibacterial mechanisms are as follows: TA might complex with enzymes or essential elements of microorganisms or directly act on microbial metabolism through inhibition of oxidative phosphorylation.1,2 Mori et al.31 demonstrated that the antibacterial ability of TA largely depended on the phenolic hydroxyl groups, which was also observed in our measurements. The results in Table 4 showed that, with the decreasing of residual phenolic hydroxyl groups per molecule, the antimicrobial activity weakened heavily. The trend was also observed in the zone of inhibition test shown in Table 2. Figure 5 displayed the antimicrobial results of TA-G5 and TA-G20 coated glass slides against Gram-positive S. aureus and Gram-negative E. coli. Numerous colonies of bacteria grew on TA-G20 coated slides after spraying the bacterial suspension onto its surface while the bacteria on the surface of slides coated with TA-G5 were hard to be distinguished. The results indicated that TA-G5 coated slides exhibited stronger antimicrobial property than those coated with TA-G20.
■
AUTHOR INFORMATION
Corresponding Author
*Tel.: +86-13912368167. Fax: +86-0510-85917763. E-mail:
[email protected]. Notes
The authors declare no competing financial interest.
■ ■
ACKNOWLEDGMENTS We acknowledge financial support from the National Natural Science Foundation of China (no. 51203063). REFERENCES
(1) Scalbert, A. Antimicrobial properties of tannis. Phytochemistry 1991, 30, 3875. (2) Akiyama, H.; Fujii, K.; Yamasaki, O.; Oono, T.; Iwatsuki, K. Antibacterial action of several tannins against Staphylococcus aureus. J. Antimicrob. Chemother. 2001, 48, 487.
10839
dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
Industrial & Engineering Chemistry Research
Article
(3) Taguri, T.; Tanaka, T.; Kouno, I. Antimicrobial activity of 10 different plant polyphenols against bacteria causing food-borne disease. Biol. Pharm. Bull. 2005, 27, 1965. (4) Kim, T. J.; Silva, J. L.; Kim, M. K.; Jung, Y. S. Enhanced antioxidant capacity and antimicrobial activity of tannic acid by thermal processing. Food Chem. 2010, 118, 740. (5) Funatogawa, K.; Hayashi, S.; Shimomura, H.; Yoshida, T.; Hatano, T.; Ito, H.; Hirai, Y. Antibacterial activity of hydrolysable tannins derived from medicinal plants against Helicobacter pylori. Microbiol. Immunol. 2004, 48, 251. (6) Tanimura, S.; Kadomoto, R.; Tanaka, T.; Zhang, Y.; Kouno, I.; Kohno, M. Suppression of tumor cell invasiveness by hydrolyzable tannins (plant polyphenols) via the inhibition of matrix metalloproteinase-2/-9 activity. Biochem. Biophys. Res. Commun. 2005, 330, 1306. (7) Mizumo, T.; Uchino, K.; Toukairin, T.; Tanabe, A.; Nakashima, H.; Yamamoto, N.; Ogawara, H. Inhibitory effect of tannic acid sulfate and related sulfates on infectivity, cytopathic effect, and giant cell formation of human immunodeficiency virus. Planta Med. 1992, 58, 535. (8) Carson, R. S.; Frisch, A. W. The inactivation of influenzae viruses by tannic acid and related compounds. J. Bacteriol. 1953, 66, 572. (9) Green, R. H. Inhibition of multiplication of influenza virus by tannic acid. Proc. Soc. Exp. Biol. Med. 1948, 67, 483. (10) Piozzi, A.; Francolini, I.; Occhiaperti, L.; Venditti, M.; Marconi, W. Antimicrobial activity of polyurethanes coated with antibiotics: A new approach to the realization of medical devices exempt from microbial colonization. Int. J. Pharm. 2004, 280, 173. (11) Travan, A.; Marsich, E.; Donati, I.; Benincasa, M.; Giazzon, M.; Felisari, L.; Paoletti, S. Silver−polysaccharide nanocomposite antimicrobial coatings for methacrylic thermosets. Acta Biomater. 2011, 7, 337. (12) Liu, Y.; Zheng, Z.; Zara, J. N.; Hsu, C.; Soofer, D. E.; Lee, K. S.; Siu, R. K.; Miller, L. S.; Zhang, X.; Carpenter, D.; Wang, C.; Ting, K.; Soo, C. The antimicrobial and osteoinductive properties of silver nanoparticle/poly (DL-lactic-co-glycolic acid)-coated stainless steel. Biomaterials 2012, 33, 8745. (13) Elegir, G.; Kindl, A.; Sadocco, P.; Orlandi, M. Development of antimicrobial cellulose packaging through laccase-mediated grafting of phenolic compounds. Enzyme Microb. Technol. 2008, 43, 84. (14) Chai, L.; Zhang, G.; Hou, H. Antimicrobial effect of polyphenols from Grifola frondosa. China Brew. 2012, 36, 91. (15) Guarda, A.; Rubilar, J. F.; Miltz, J.; Galotto, M. J. The antimicrobial activity of microencapsulated thymol and carvacrol. Int. J. Food Microbiol. 2011, 146, 144. (16) Zasloff, M. Antimicrobial peptides of multicellular organisms. Nature 2002, 415, 389. (17) Li, Y.; Kumar, K. N.; Dabkowski, J. M.; Corrigan, M.; Scott, R. W.; Nüsslein, K.; Tew, G. N. New bactericidal surgical suture coating. Langmuir 2012, 28, 12134. (18) Klibanov, A. M. Permanently microbicidal materials coatings. J. Mater. Chem. 2007, 17, 2479. (19) Seong, H. S.; Whang, H. S.; Ko, S. W. Synthesis of a quaternary ammonium derivative of chito-oligosaccharide as antimicrobial agent for cellulosic fibers. J. Appl. Polym. Sci. 2000, 76, 2009. (20) Feese, E.; Sadeghifar, H.; Gracz, H. S.; Argyropoulos, D. S.; Ghiladi, R. A. Photobactericidal porphyrin-cellulose nanocrystals: Synthesis, characterization, and antimicrobial properties. Biomacromolecules 2001, 12, 3528. (21) Fernandes, S. C. M.; Sadocco, P.; Alonso-Varona, A.; Palomares, T.; Eceiza, A.; Silvestre, A. J. D.; Mondragon, I.; Freire, C. S. R. Bioinspired antimicrobial and biocompatible bacterial cellulose membranes obtained by surface functionalization with aminoalkyl groups. ACS Appl. Mater. Interfaces 2013, 5, 3290. (22) Fernandes, S. C. M.; Sadocco, P.; Causio, J.; Silvestre, A. J.; Mondragon, I.; Freire, C. S. R. Antimicrobial pullulan derivative prepared by grafting with 3-aminopropyltrimethoxysilane: Characterization and ability to form transparent films. Food Hydrocolloids 2014, 35, 247.
(23) Widsten, P.; Heathcote, C.; Kandelbauer, A.; Guebitz, G.; Nyanhongo, G. S.; Prasetyo, E. N.; Kudanga, T. Enzymatic surface functionalisation of lignocellulosic materials with tannins for enhancing antibacterial properties. Process Biochem. 2010, 45, 1072. (24) Yagci, M. B.; Bolca, S.; Heuts, J. P. A.; Ming, W.; With, G. Antimicrobial polyurethane coatings based on ionic liquid quaternary ammonium compounds. Prog. Org. Coat. 2011, 72, 343. (25) Xiao, P.; Webster, D. C. Impact of structure and functionality of core polyol in highly functional biobased epoxy resins. Macromol. Rapid Commun. 2011, 32, 1324. (26) Schmidt, L. E.; Schmäh, D.; Leterrier, Y.; Månson, J-A. E. Timeintensity transformation and internal stress in UV-curable hyperbranched acrylates. Rheol. Acta 2007, 46, 693. (27) Wu, J. F.; Fernando, S.; Jagodzinski, K.; Weerasinghe, D.; Chen, Z. Effect of hyperbranched acrylates on UV-curable soy-based biorenewable coatings. Polym. Int. 2011, 60, 571. (28) Chen, X.; Li, G.; Lian, J.; Jiang, Q. Study of the formation and growth of tannic acid based conversion coating on AZ91D magnesium alloy. Surf. Coat. Technol. 2009, 204, 736. (29) Yagci, M. B.; Bolca, S.; Heutsc, J. P. A.; Ming, W.; With, G. Selfstratifying antimicrobial polyurethane coatings. Prog. Org. Coat. 2011, 72, 305. (30) Wynne, J. H.; Fulmer, P. A.; McCluskey, D. M.; Mackey, N. M.; Buchanan, J. P. Synthesis and development of a multifunctional selfdecontaminating polyurethane coating. ACS Appl. Mater. Interfaces 2011, 3, 2005. (31) Mori, A.; Nishino, C.; Enoki, N.; Tawata, S. Antibacterial activity and mode of action of plant flavonoids against Proteus vulgaris and Staphylococcus aureus. Phytochemistry 1987, 26, 2231.
10840
dx.doi.org/10.1021/ie501804p | Ind. Eng. Chem. Res. 2014, 53, 10835−10840
