Antibiofilm Effects of Heated Scallop Shell Powder on Campylobacter jejuni Biofilms

Methods to reuse large numbers of scallop shells from the harvesting regions of Japan are being explored. The major component of scallop shells is calcium carbonate (CaCO3), which forms the powerful bactericidal agent, calcium oxide (CaO), when heated. Heated scallop shell powder (HSSP) exhibits strong and broad-spectrum antimicrobial activity against bacteria, fungi, and viruses. This study investigated the antibiofilm activity of HSSP against the biofilms of Campylobacter jejuni, which is the predominant species in campylobacteriosis. Biofilm samples of C. jejuni were prepared on 0.45 µm filter paper under microaerobic conditions. The HSSP treatment inactivated and eradicated C. jejuni biofilms. The resistance of C. jejuni biofilms to HSSP was significantly higher than that of the floating cells. Moreover, the antibiofilm activity of the HSSP treatment against C. jejuni biofilms was higher than that of NaOH treatment at the same pH. These results indicated that HSSP treatment is an effective method for controlling C. jejuni biofilms.

Degradation Analysis of Jute Fiber Reinforced Waste Tile Powder-Filled Polymer Composite on Wear Characteristics

In this study, a polymer composite is made using chemically treated jute fiber and waste floor tile powder as an alternative source for roof tile application. The wear qualities were examined at various ages, and the outcomes were optimized. In order to improve the wetting properties of the jute fiber, it was chemically treated. MINITAB software was used to develop Taguchi method parameters such as jute fiber percentage, waste tile powder percentage, and NaOH chemical treatment using the MINITAB software. It was determined that hardness was the most important characteristic in terms of wear properties after the specimens were subjected to ageing and abrasion wear testing and hardness tests were carried out as per normal protocols. As a result of the waste tile powder addition, the surface and core pore formation rates were reduced and the wear index rates were low. Jute fiber with 15%, 9% tile powder, and 5% NaOH treatment were found to have the lowest wear index of the other specimen compositions tested, according to the wear index. Specimen made with 5% jute fiber addition, 9% tile powder inclusion, and 10% NaOH treatment, on the other hand, had more hardness. Degradation of the fibers and delamination are side effects of the ageing process. The wear resistance of the surface was increased by the use of waste tile powder.

Improved Adsorption of the Antimicrobial Agent Poly (Hexamethylene) Biguanide on Ti-Al-V Alloys by NaOH Treatment and Impact of Mass Coverage and Contamination on Cytocompatibility

Unlike the native surface of the implant material (Ti6Al4V), oxidation with H2O2 leads to increased binding of the effective antimicrobial agent poly(hexamethylene) biguanide [PHMB]. However, treating with NaOH instead results in an even higher PHMB mass coverage. After oxidation with H2O2, strong differences in the PHMB adsorption capability between polished and corundum-blasted surfaces appear, indicating a roughness dependence. After NaOH treatment, no such effect was observed. The wetting properties of specimens treated with either H2O2 or NaOH prior to PHMB exposure clearly varied. To unravel the nature of this interaction, widespread in silico and in vitro experiments were performed. Methods: By X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurements and MD simulations, we characterized the interplay between the polycationic antimicrobial agent and the implant surface. A theoretical model for PHMB micelles is tested for its wetting properties and compared to carbon contaminated TiO2. In addition, quantitation of anionic functional group equivalents, the binding properties of PHMB with blocked amino end-group, and the ability to bind chlorhexidine digluconate (CHG) were investigated. Ultimately, the capability of osteoblasts to build calcium apatite, and the activity of alkaline phosphatase on PHMB coated specimens, were determined. Results: Simulated water contact angles on carbon contaminated TiO2 surfaces and PHMB micelle models reveal little influence of PHMB on the wetting properties and point out the major influence of remaining and recovering contamination from ambient air. Testing PHMB adsorption beyond the critical micelle concentration and subsequent staining reveals an island-like pattern with H2O2 as compared to an evenly modified surface with NaOH. Both CHG and PHMB, with blocked amino end groups, were adsorbed on the treated surfaces, thus negating the significant influence of PHMB’s terminal groups. The ability of osteoblasts to produce calcium apatite and alkaline phosphatase is not negatively impaired for PHMB mass coverages up to 8 μg/specimen. Conclusion: Differences in PHMB adsorption are triggered by the number of anionic groups and carbon contaminants, both of which depend on the specimen pre-treatment. With more PHMB covering, the implant surface is protected against the capture of new contamination from the ambient air, thus building a robust antimicrobial and biocompatible surface coating.

Cornhusk retting by pectinase enzyme combined with NaOH and effects on fiber properties

Cornhusk fiber is a kind of biodegradable lignocellulosic fiber. The conditions of enzyme and NaOH retting were optimized on the basis of weight loss rate and the Fried test score to extract the cornhusks fiber. Taking raw cornhusk fiber as a contrast, physicochemical properties of the fiber extracted from cornhusk was researched in detail by chemical analysis (GB5889-86), X-ray diffraction and Fourier-transform infrared spectroscopy (FTIR). The optimal retting condition of cornhusk fiber is the following: Pectinase 9032 0.5% concentration, at 40–55°C, pH 4.2–5.8, and then 5% NaOH treatment for 15 min. The crystallinity index of raw cornhusk fiber, enzyme-treated cornhusk fiber and enzyme-alkali-treated cornhusk fiber are 20.30%, 35.05% and 51.00%, respectively, and the structure of these fibres all correspond to cellulose I. The FTIR spectra showed that higher amounts of lignin and hemicellulose were removed by NaOH treatment compared with enzyme treatment.

SINTEZA I STRUKTURA BAKTERIJSKE CELULOZE PRIMENOM BAKTERIJA SIRĆETNOG VRENJA

As one of the most common biopolymers on Earth, cellulose has found an important role in food industry, biomedicine andbiotechnology. The process of obtaining cellulose fibers is often followed with the presence of the byproduct, whose removal is required procedure. From that reason, the process of obtaining material on a bacterial cellulose (BC) basis,finds wide application in everyday life. Having in mind her many features, we have investigated the change in structure and morphology of BC depending on the synthesis parameters. The influence of the medium volume and different time intervals of NaOH treatment relative to different BCN yields and structure. The mentioned changes were examined by XRD, FTIR spectroscopy, as well as SEM and EDS analyzes.