• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.30 no.4
• /
• pp.59-68
• /
• 1998

This study was to investigate the effect of chitosan molecular weight, its charge density, and its surface coating treatment on the antibacterial properties of paper. For this study, E.coil was used for antibacterial experiment. Results obtained were as follows : 1. The antibacterial properties of chitosan was significant on the surface-treated sheet. 2. Antibacterial property surface treatment was appeared to be effective when film was formed on the paper surface. 3. The antibacterial properties of chitosan-treated paper was dependent on the amount and the molecular weight of chitosan used. The lower the molecular weight of the chitosan down to 30,000 the better the antibacterial properties in this experiment. 4. Determination of the degree of chitosan-deacetylation by colloidal titration method was consistent with the more complicated and conventional FT-IR method.

• Elastomers and Composites
• /
• v.56 no.4
• /
• pp.254-263
• /
• 2021

In this study, chitosan obtained after varying extents of deacetylation (i.e., 10%, 30%, and 47%) was employed to introduce antibacterial properties to chitin. The deacetylation reaction completion, wherein the amino group content of chitin was reduced, was ascertained from the FT-IR and NMR analyses. The 47%-deacetylated chitosan exhibited superior antibacterial properties against Bacillus in a disk diffusion test. To further improve these properties, chitosan derivatives were grafted by acrylic acid and acrylamide. The varying concentrations of carboxyl groups, primary amines, and -CH₂-CH₂- with increasing acrylic acid and acrylamide contents were determined by FT-IR and NMR analyses. The enhanced antibacterial properties of the chitosan derivatives, owing to the increased acrylic acid and acrylamide contents, were revealed by the disk diffusion test. In particular, the derivatives with 1.3% acrylic acid and acrylamide showed the highest antibacterial activity, the bacterial reduction rate against Staphylococcus aureus and Escherichia coli being 99.9%, as observed through the ASTM E2149 standard test.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.44 no.3
• /
• pp.34-40
• /
• 2012

In this study, new antibacterial materials were developed to manufacture a functional corrugated board. Sulfur solution, a new antibacterial solution made from inorganic sulfur in the laboratory, and other antibacterial mat erials were adopted to treat the surface of a linerboard. We measured the antibacteriocidal and bacteriostatic activities, as well as the fungal resistance of the surface-treated linerboards, to identify the antibacterial properties. The mechanical properties of the surface-treated linerboard were also determined in order to identify the effects of the antibacterial materials on linerboard properties. Linerboard treated with sulfur solution, PVOH, and sodium metasulfite showed the highest antibacterial activity, while linerboard treated with sulfur solution and nano sulfur showed the highest fungal resistance. It was identified that sulfur solution has effective antibacterial properties. The antibacterial materials did not affect the mechanical properties of the surface-treated linerboard, but the binder showed significant effects in terms of the burst strength, the compressive strength, and the stiffness of the linerboard.

• Membrane and Water Treatment
• /
• v.8 no.5
• /
• pp.463-481
• /
• 2017

Bacteria have been considered as a major foulant that initiates the formation of biofilm on the polymeric membrane surface. Some polymeric membranes are naturally antibacterial and have low fouling properties, however, numerous efforts have been devoted to improve their antibacterial performance. These modifications are mostly carried out through blending the membrane with an antibacterial agent or introducing the antibacterial agent on the membrane surface by chemical grafting. Currently, a significant number of researches have reported nanocomposite membrane as a new approach to fabricate an excellent antibacterial membrane. The antibacterial nanoparticles are dispersed homogenously in membrane structure by blending method or coating onto the membrane surface. Aim of the modifications is to prevent the initial attachment of bacteria to membrane surface and kill bacteria when attached on the membrane surface. In this paper, several studies on antibacterial modified membranes, particularly for water treatment, will be reviewed comprehensively. Special attention will be given on polymeric membrane modifications by introducing antibacterial agents through different methods, such as blending, grafting, and coating.

• Elastomers and Composites
• /
• v.52 no.3
• /
• pp.201-210
• /
• 2017

We studied the antibacterial effect and mechanical properties of PLA composites with in organic porous zeolite-type bacteriocides. The specimens were prepared by an intermeshing co-rotating twin screw extruder using different contents of inorganic bacteriocide. The degree of dispersion of the in organic bacteriocide in the PLA composite was confirmed by FE-SEM. The contents of Ag and Zn in the composite were also investigated by energy dispersive spectroscopy at different concentrations of the inorganic bacteriocide. The antibacterial effects were analyzed by turbidity analysis, shaking culture, and drop-test. The mechanical properties, such as the tensile and flexural properties, impact strength, and physical properties, were also investigated. As the content of inorganic bacteriocide increased, the antibacterial activity was increased, especially against Staphylococcus aureus. Mechanical properties, namely, tensile strength, elongation, flexural strength, and impact strength, tended to decrease with an increase in inorganic bacteriocide content, but the tensile and flexural modulus increased.

• Genomics & Informatics
• /
• v.16 no.3
• /
• pp.44-51
• /
• 2018

Fluoroquinolone (FQ) antibiotics are an important class of synthetic antibacterial agents. These are the most extensively used drugs for treating bacterial infections in the field of both human and veterinary medicine. Herein, the antibacterial and pharmacological properties of four fluoroquinolones: lomefloxacin, norfloxacin, ciprofloxacin, and ofloxacin have been studied. The objective of this study was to analyze the antibacterial characteristics of the different fluoroquinolones. Also, the pharmacological properties of the compounds including the Lipinski rule of five, absorption, distribution, metabolism, and excretion, LD50, drug likeliness, and toxicity were evaluated. We found that among all four FQ molecules, ofloxacin showed the highest antibacterial activity through in silico assays with a strong interaction (-38.52 kJ/mol) with the antibacterial target protein (topoisomerase-II DNA gyrase enzyme). The pharmacological and pharmacokinetic analysis also showed that the compounds ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin have good pharmacological properties. Notably, ofloxacin was found to possess an IGC50 (concentration needed to inhibit 50% growth) value of $0.286{\mu}g/L$ against the Tetrahymena pyriformis protozoa. It also tested negative for the Ames toxicity test, showing its non-carcinogenic character.

• Journal of Korean society of Dental Hygiene
• /
• v.23 no.6
• /
• pp.459-466
• /
• 2023

Objectives: The purpose of this study was to evaluate the physical properties and antibacterial activity of denture base resin with added silver sulfadiazine. Methods: Specimens were made from self-curing denture base resin and silver sulfadiazine as an inorganic antibacterial agent. For physical evaluation of the specimens, surface roughness, surface hardness, and contact angle were measured. Bacterial growth was assessed by optical densityat 600 nm (OD600) and colony forming units (CFU) measurements to confirm antibacterial activity. Results: There was no significant difference in surface roughness, surface hardness, and contact angle in the experimental group containing silver sulfadiazine compared to the control group. In contrast, the experimental group showed a significant decrease in antibacterial activity compared to the control group in terms of OD value. Analysis of CFU confirmed a significant decrease in colonies in the experimental group compared to the control group. Conclusions: Denture base resin containing silver sulfadiazine, an inorganic antibacterial agent, exhibited enhanced antibacterial activity without physical changes. In conclusion, the use of denture base resin containing inorganic antibacterial agents may be expected in the future.

• Restorative Dentistry and Endodontics
• /
• v.39 no.2
• /
• pp.109-114
• /
• 2014

Objectives: Recurrent caries was partly ascribed to lack of antibacterial properties in composite resin. Silver and zinc nanoparticles are considered to be broad-spectrum antibacterial agents. The aim of the present study was to evaluate the antibacterial properties of composite resins containing 1% silver and zinc-oxide nanoparticles on Streptococcus mutans and Lactobacillus. Materials and Methods: Ninety discoid tablets containing 0%, 1% nano-silver and 1% nano zinc-oxide particles were prepared from flowable composite resin (n = 30). The antibacterial properties of composite resin discs were evaluated by direct contact test. Diluted solutions of Streptococcus mutans (PTCC 1683) and Lactobacillus (PTCC 1643) were prepared. 0.01 mL of each bacterial species was separately placed on the discs. The discs were transferred to liquid culture media and were incubated at $37^{\circ}C$ for 8 hr. 0.01 mL of each solution was cultured on blood agar and the colonies were counted. Data was analyzed with Kruskall-Wallis and Mann-Whitney U tests. Results: Composites containing nano zinc-oxide particles or silver nanoparticles exhibited higher antibacterial activity against Streptococcus mutans and Lactobacillus compared to the control group (p < 0.05). The effect of zinc-oxide on Streptococcus mutans was significantly higher than that of silver (p < 0.05). There were no significant differences in the antibacterial activity against Lactobacillus between composites containing silver nanoparticles and those containing zinc-oxide nanoparticles. Conclusions: Composite resins containing silver or zinc-oxide nanoparticles exhibited antibacterial activity against Streptococcus mutans and Lactobacillus.

• Restorative Dentistry and Endodontics
• /
• v.7 no.1
• /
• pp.47-52
• /
• 1981

The purpose of this study is to determine the antibacterial effect of Dilute Formocresol and Eugenol and Propylene glycol. The experimental drugs are Formocresol in Propylene glycol (5, 10, 20%) and Eugenol in Propylene glycol (50, 75, 100%) and Propylene glycol. The organisms selected for study were Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis which are found in infected root canals and are highly resistant to antiseptics. Isolated bacteria were inoculated on blood agar plate and the plates were incubated at $37^{\circ}C$ for 18 hours and the zones of inhibition then measured. The results were as follows ; 1. The antibacterial action of Formocresol was effective even at 5-10 percent and the action increased when higher concentration was used. 2. The antibacterial action of Eugenol was not effective and the action decreased when higher concentration was used. 3. Propylene glycol itself possessed some antibacterial properties and showed that the antibacterial action of Propylene glycol might be almost the same as that of Eugenol. 4. Among the experimental organisms, Pseudomonas aeruginosa was found to be the most resistant to all the experimental drugs.

• Fashion & Textile Research Journal
• /
• v.23 no.6
• /
• pp.836-843
• /
• 2021

Recently, with an increase of interest in hygiene of textile products, research related to finishing technology to impart various functionalities, such as antibacterial and deodorizing properties, has also required. Therefore, in this study, the improvement of comfort was examined by analyzing the change of moisture characteristics and antibacterial and deodorizing properties of underwear fabric by chitosan microcapsule(CH-M) finishing. The results revealed that moisture absorption time of the fabric shortened, diffusion rate increased, while absorption rate slightly increased because of microcapsule finishing. In addition, the one-way transfer capacity of the microcapsule finished fabric was 17.69, which improved moisture transfer to one side, while OMMC showed the values of 0.32 and 0.37 for untreated and finished fabrics, respectively, which slightly increased after finishing. In the case of untreated fabric, antibacterial activity was 89.0% against Staphylococcus aureus and 70.3% against Klebsiella pneumoniae; however, both strains showed 99.9% antibacterial activity by CH-M finishing. An excellent bacterial reduction rate was also observed. In the case of the CH-M finished fabric, there was a deodorization effect exceeding 99% up to 120 minutes, and it showed an excellent deodorization effect of more than 99% even after 10 repeated washings.