Papers by Keyword: Antibacterial Properties

Abstract: Surface modification of metallic materials to impart antibacterial properties has attracted significant attention for practical applications in biomedical and industrial fields. This study aims to characterise the antibacterial surface textures of Ti alloys (Ti-6Al-4V) and investigate their relationship with water repellency, bio-adhesion resistance, and antibacterial performance. Two distinct surface textures were fabricated using chemical (acid treatment for 5 and 20 min) and physical methods (tensile testing). Antibacterial tests revealed 41.6%, 14.6%, and 31% reductions in the viable bacterial counts for the 5-minute acid-treated, 20-minute acid-treated, and tensile-tested samples, respectively, compared to untreated controls. Contact angles of 100.9°, 96.1°, and 79° were observed, indicating varying degrees of water repellency. The acid-treated samples exhibited reduced bio-adhesion, whereas the tensile-tested samples showed increased bio-adhesion. These findings suggest that the surface morphology that inhibits bacterial aggregation is the primary factor contributing to antibacterial properties. Although water repellency and bio-adhesion resistance are often associated with antibacterial surfaces, they serve as functional correlations rather than direct determinants. The surface texture developed in this study exhibited a symmetrical vertical height distribution with Sa = 0.24 µm and featured flat valley regions, rendering it highly suitable for antibacterial applications and promising for use in biocompatible environments.

Abstract: The green synthesis of silver nanoparticles (AgNPs) using plant extracts has gained significant attention due to its eco-friendly, cost-effective, and non-toxic approach. This study reports the synthesis of AgNPs using Telfairia occidentalis (fluted pumpkin) leaf extract as a reducing and stabilizing agent. The phytochemical screening of Telfairia occidentalis showed that saponin, tannin, flavonoid, steroid and terpenoid are present in the sample. The synthesized AgNPs were characterized using UV-Vis spectroscopy, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM) was used to characterize the developed composites. Furthermore, the bactericidal efficiency of AgNPs-doped epoxy composites was evaluated against Escherichia coli and Staphylococcus aureus to assess their antimicrobial properties. It was observed that the inhibition zone increases with the increase in AgNPs in the composites. The results indicate that the synthesized AgNPs exhibit potent antimicrobial activity, making them suitable for biomedical and industrial applications. Keywords: Green synthesis, Silver nanoparticles, Telfairia occidentalis, Epoxy composite, Antibacterial properties.

Abstract: Calcium silicate-based cements have been investigated recently for various medical applications. One notable application is using calcium silicate cement in dental root canal treatments. This work aimed to develop a novel flowable dual-paste calcium silicate sealer with an extended capacity for releasing antibiotic drugs. This study prepared a composite dental cement incorporating tri- and dicalcium silicate (C₂S and C₃S) and nano-hydroxyapatite (nHA). International standards are followed by the sealers' film thickness, flowability values, working time, and setting time. The formation of calcium hydroxide and calcium silicate hydrate was proved in the XRD patterns, which attributed to the hydration of C₂S and C₃S. The in vitro release of Amoxicillin (AMX) loaded in the composite cement was conducted in deionized (DI) water and phosphate-buffered saline (PBS) and investigated using Higuchi and Weibull models. Upon immersion in PBS, the sedimentation of hydroxyapatite layer on the cement surface, led to a comparatively slower AMX release rate than that in water. The results of the agar diffusion test showed that the presence of the antibiotic drug improved antibacterial properties in such a way that by adding AMX in the cement formulation, the diameter of the inhibition zone increased from 31.61 mm in TCS to 40.17 mm in TCS- 30 mM sample after 72 hours. These results imply that the drug-loaded cement pastes hold potential for application as a bioactive dental root canal sealer, offering antibiotic-loading properties with long-term release capabilities.

Abstract: Amongst biomedical metallic materials, titanium alloys are normally used as structural permanent implants due to their favourable combination of mechanical properties and biocompatibility. However, commonly implanted titanium alloys are expensive and, unless purposely surface treated, generally cannot prevent surgical infections related to bacteria. Specifically, bacterial infection in biomedical protheses leads to inflammation, obstruction of the healing process, prevention of osteogenesis and, eventually, premature failure of the implant. This work therefore analysis the development of new ternary Ti-based alloys with built-in antibacterial capability as pathogenic bacterial infection occurring during surgery is a raising issue of metallic biomedical implants. The new Ti-based alloys were designed to be manufactured via powder metallurgy, which permits to successfully produce chemically homogeneous materials, key for a uniform antibacterial response, at lower cost. It is found that, primarily due to the stabilisation of the beta phase, the amount of the selected β stabilising alloying elements directly increases the mechanical performance and the antibacterial capability. Consequently, new ternary Ti-based alloys are promising candidates for structural prosthesis functionalised with antibacterial capability.

Abstract: In the medical industry the medical device sector is a domain dynamic and growing, that involved important efforts performance for imposing new material to support the development of new products. Manufacturers of medical devices for single use, are constantly looking for new products and new materials to expand their capabilities.

Abstract: The present research reports on flax textile modification by the use of sol-gel technology with the purpose to determine their antibacterial properties. The evaluation of antibacterial activity against pathogenic microorganisms Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli was carried out by the Parallel streak method in accordance with the ATCC147 standard. The morphological changes on the flax textile surface before and after coating were evaluated by Scanning Electron Microscopy (SEM). It has been concluded that the sol-gel treatment can impart antibacterial properties to flax textiles against all tested bacteria preventing the bacteria growth.

Abstract: Ag-natural rubber (Ag-NR) hybrid sheets were successfully prepared with a very simple and low cost method. In this method, silver nanoparticles (AgNPs) were firstly synthesized by a rapid and green microwave-assisted using polyvinylpyrroridone (PVP) media. The effect of PVP weight ratios towards the size of AgNPs was also investigated. Then, Ag-NR hybrid sheet samples were prepared by latex mixing-casting method using concentrated natural rubber (NR) latex with the synthesized AgNPs colloids. The characteristic absorption, particles sizes and shapes of the obtained AgNPs were examined through UV-vis, TEM and SAED. Also, the prepared Ag-NR sheet samples were characterized using XRD, FT-IR, SEM and EDS techniques. It was found that the particles sizes of all the synthesized AgNPs had spherical-like shape, and the mean sizes were increased from 29.7 to 90.4 nm upon increasing PVP contents. EDS results showed the AgNPs were well-dispersed and impregnated into the rubber matrix. Moreover, the antibacterial properties of the prepared Ag-NR sheets were tested by agar disk-diffusion method with Gram-positive and Gram-negative bacteria as Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. The results showed that the hybrid sheets exhibited excellent antibacterial properties against these bacteria, in which the zones of inhibition were also dependent on the synthesized AgNPs by utilizing the different amounts of PVP.

Abstract: Cu/TiO₂ nanocomposite was first prepared by photocatalytic reduction according to optimal processing condition selected via orthogonal test: 2.0% of glucose, 0.25% of TiO₂, 0.3% of CuCl ₂ and reaction time of 12 h. Multiple characterization methods were utilized to confirm the structure of Cu/TiO₂ nanocomposite, and its antibacterial property against Escherichia coli (E.coli) was then investigated in detail. The obtained Cu/TiO₂ (ca. 50 nm) was composed of elemental copper, TiO₂ and a small amount of unreacted CuCl₂. EDTA titration and XRF indicated that solid content of Cu was about 61.68%. Antibacterial test showed that the inhibition zone diameter of Cu/TiO₂ with 1% solid content is 15.77 mm and the minimum bactericidal concentration (MBC) of which is 5 mg/mL. Furthermore, Cu/TiO₂ (1.0 wt%) was added into a super-hydrophilic coating for the aluminum cooling fin of air conditioner. The antibacterial ability of the fin can be significantly improved without obvious changes of hydrophilicity, which can reach the national standard (grade I).

Abstract: With the H₂C₂O₄·2H₂O and Mg(NO₃)₂·6H₂O as the raw materials, nanometer-MgO powder was synthesized at different temperature by the low temperature solid phase method. After the characterization of the structure and property of this kind of nanometer-MgO powder with TG, XRD, SEM and FT-IR, etc, the antibacterial property of nanometer-MgO powder to Escherichia Coli and Staphylococcus Aureus was examined through the bacteriostatic circle method. The results indicated that the powder was single crystal, complete crystallization and uniform distribution with the 10 nm of particle size. It had better resistance and capacity of killing bacteria and the diameter of the bacteriostatic circle was greater than 19 mm.

Abstract: Elimination of microorganisms from the root canal system and the prevention of subsequent reinfection are of importance for long-term endodontic treatment. The application of a sealer with antibacterial properties may reduce the reinfection and improve the success rate of the root filling treatment. The aim of this paper is to evaluate the antibacterial properties of a novel root canal sealer based on injectable self-curing polyurethane with silver phosphate (PU/Ag₃PO₄). The antibacterial abilities were assessed by direct contact test, anti-bacterial adhesion assay and bacteriostatic rate test. The results show that the fabricated PU/Ag₃PO₄ sealer can completely inhibit the bacterial growth and prevent bacterial adhension effectively. The bacteriostatic rate is 93.6% and 98.1% when the bacteria incubated with PU/Ag3PO4 sealer for 7 and 24h respectively. The strong antibacterial abilities suggest that PU/Ag3PO4 sealer has great application potential in the field of root canal filling.Key words: Root canal sealer, polyurethane, silver phosphate, antibacterial properties, direct contact test