An eco-friendly facile approach for imparting multifunctional protection properties to cellulose/wool blends

A green facile nano-finishing route was developed to impart high antibacterial efficacy, UV-protection, self-cleaning and anti-wrinkle functions to cotton/wool and viscose/wool blends using TiO2, and/or Ag-NPs, as active ingredients, along with citric acid and/or succinic acid/ SHP as ester-crosslinking/fixing systems. The data so obtained demonstrated that outstanding durable functional properties can be achieved using the following formulation: TiO2/Ag-NPs (20 g/L each), citric acid/SHP (50 g/L/30 g/L) and the pad- dry microwave fixation at 1300 W for 5 min. SEM and EDX analysis for selected samples as well mode of interactions among the nominated finishing ingredients and the treated substrates were also investigated.

Assessment of Plant Species Suitability in Green Walls Based on API, Heavy Metal Accumulation, and Particulate Matter Capture Capacity

Today, one of the most pressing issues confronting the civilized and modern world is air pollution. Particulate matter (PM) is a well-known pollutant that contributes significantly to urban air pollution and has numerous short- and long-term adverse effects on human health. One method of reducing air pollution is to create green spaces, mainly green walls, as a short-term solution. The current study investigated the ability of nine plant species to reduce traffic-related PM using a green wall system installed along a busy road in Mashhad, Iran. The main aims were (1) estimate the tolerance level of plant species on green walls to air pollution using the Air pollution tolerance index (APTI); (2) assess the PM capture on the leaves of green wall species using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) analysis and accumulation of heavy metals using Inductively Coupled Plasma (ICP); (3) select the most tolerance species for reducing air pollution using Anticipated Performance Index (API). The plants' APTI values ranged from 5 to 12. The highest APTI value was found in Carpobrotus edulis and Rosmarinus officinalis, while Kochia Prostrata had the lowest. Among the APTI constituents, leaf water content (R2 = 0.29) and ascorbic acid (R2 = 0.33) had a positive effect on APTI. According to SEM analysis, many PM were adsorbed on the adaxial and abaxial leaf surfaces, as well as near the stomata of Lavandula angustifolia, C. edulis, Vinca minor, and Hylotelephium sp. Based on EDX analysis, carbon and oxygen formed the highest amount (more than 60%) of metals detected in the elemental composition of PM deposited on the leaves of all species. The Sedum reflexum had the highest Cr, Fe, Pb, and As accumulation. The concentrations of all heavy metals studied in green wall plants were higher than in the control sample. Furthermore, the C. edulis is the best plant for planting in industrial, urban areas of the city based on APTI, biological, economic, and social characteristics. It concludes that the use of green walls composed primarily of plants with small leaves can significantly adsorb PM and accumulation of heavy metal.

Biologically formed silver nanoparticles and in vitro study of their antimicrobial activities on resistant pathogens

Background and Objectives: Silver nanoparticles (AgNPs) have been found to have multiple uses as antibacterial, anti- fungal and anti-biofilm agents because of their biological activities and safety. The present study was aimed to analyze the antimicrobial and anti-biofilm activities as well as the cytotoxic effect of AgNPs against different human pathogens. Materials and Methods: AgNPs were synthesized using cell free supernatants of Escherichia coli (ATCC 25922), En- terococcus faecalis (ATCC 19433), Pseudomonas aeruginosa (ATCC 27856), Enterobacter cloacae (ATCC 13047) and Penicillium oxalicum strain, then were analyzed using UV/Vis Spectral Analysis, Transmission electron microscopy (TEM). Scanning Electron Microscope (SEM) and Energy Dispersive-X-ray Spectroscopy (EDX) analysis. Antimicrobial activities of biosynthesized AgNPs were assessed with selected antimicrobial agents against multidrug resistant bacteria and candida. Anti-biofilm and cytotoxicity assays of these biosynthesized AgNPs were also done. Results: The synthesis of AgNPs were confirmed through observed color change and monitoring UV-Vis spectrum which showed homogeneous (little agglomeration) distribution of silver nanoparticles. TEM and SEM have shown that the parti- cle size ranged from 13 to 34 (nm) with spherical shape and a high signal with EDX analysis. Antibacterial and antifungal efficacy of antibiotics and fluconazole were increased in combination with biosynthesized AgNPs against resistant bacteria and candida. Significant reduction in biofilm formation was found better with Penicillium oxalicum AgNPs against biofilm forming bacteria. Conclusion: Penicillium oxalicum has the best effect towards synthesizing AgNPs, for antimicrobial activities against resis- tant bacteria and candida, in addition to anti-biofilm activities against biofilm forming Staphylococcus aureus and E. coli and the safest cytotoxicity effect on (MRC-5) cell line.

Direct monitoring of single-cell response to biomaterials by Raman spectroscopy

There is continued focus on the development of new biomaterials and associated biological testing methods needed to reduce the time taken for their entry to clinical use. The application of Raman spectroscopy to the study of individual cells that have been in contact with biomaterials offers enhanced in vitro information in a potentially non-destructive testing regime. The work presented here reports the Raman spectral analysis of discreet U-2 OS bone cells after exposure to hydroxyapatite (HA) coated titanium (Ti) substrates in both the as-deposited and thermally annealed states. These data show that cells that were in contact with the bioactive HA surface for 7 days had spectral markers similar to those cultured on the Ti substrate control for the same period. However, the spectral features for those cells that were in contact with the annealed HA surface had indicators of significant differentiation at day 21 while cells on the as-deposited surface did not show these Raman changes until day 28. The cells adhered to pristine Ti control surface showed no spectral changes at any of the timepoints studied. The validity of these spectroscopic results has been confirmed using data from standard in vitro cell viability, adhesion, and proliferation assays over the same 28-day culture period. In this case, cell maturation was evidenced by the formation of natural bone apatite, which precipitated intracellularly for cells exposed to both types of HA-coated Ti at 21 and 28 days, respectively. The properties of the intracellular apatite were markedly different from that of the synthetic HA used to coat the Ti substrate with an average particle size of 230 nm, a crystalline-like shape and Ca/P ratio of 1.63 ± 0.5 as determined by SEM-EDX analysis. By comparison, the synthetic HA particles used as a control had an average size of 372 nm and were more-rounded in shape with a Ca/P ratio of 0.8 by XPS analysis and 1.28 by SEM-EDX analysis. This study shows that Raman spectroscopy can be employed to monitor single U-2 OS cell response to biomaterials that promote cell maturation towards de novo bone thereby offering a label-free in vitro testing method that allows for non-destructive analyses.

Biocompatibility Analyses of HF-Passivated Magnesium Screws for Guided Bone Regeneration (GBR)

Background: Magnesium (Mg) is one of the most promising materials for human use in surgery due to material characteristics such as its elastic modulus as well as its resorbable and regenerative properties. In this study, HF-coated and uncoated novel bioresorbable magnesium fixation screws for maxillofacial and dental surgical applications were investigated in vitro and in vivo to evaluate the biocompatibility of the HF coating. Methods: Mg alloy screws that had either undergone a surface treatment with hydrofluoric-acid (HF) or left untreated were investigated. In vitro investigation included XTT, BrdU and LDH in accordance with the DIN ISO 10993-5/-12. In vivo, the screws were implanted into the tibia of rabbits. After 3 and 6 weeks, degradation, local tissue reactions and bony integration were analyzed histopathologically and histomorphometrically. Additionally, SEM/EDX analysis and synchrotron phase-contrast microtomography (µCT) measurements were conducted. The in vitro analyses revealed that the Mg screws are cytocompatible, with improved results when the surface had been passivated with HF. In vivo, the HF-treated Mg screws implanted showed a reduction in gas formation, slower biodegradation and a better bony integration in comparison to the untreated Mg screws. Histopathologically, the HF-passivated screws induced a layer of macrophages as part of its biodegradation process, whereas the untreated screws caused a slight fibrous tissue reaction. SEM/EDX analysis showed that both screws formed a similar layer of calcium phosphates on their surfaces and were surrounded by bone. Furthermore, the µCT revealed the presence of a metallic core of the screws, a faster absorbing corrosion front and a slow absorbing region of corroded magnesium. Conclusions: Overall, the HF-passivated Mg fixation screws showed significantly better biocompatibility in vitro and in vivo compared to the untreated screws.

Performance of Concrete Mixes Containing TBM Muck as Partial Coarse Aggregate Replacements

This study investigated the potential utilization of the TBM muck obtained from the Gold Line of the Doha Metro Project as a partial replacement of coarse aggregates in concrete mixes. First, the TBM muck particles were screened to coarse aggregate standard sizes. Then, concrete mixes were prepared using 0%, 25%, 50%, and 75% TBM muck replacement of coarse aggregates. The compressive and flexural strengths were determined for all mixes at 28 and 56 days. Moreover, the results obtained were validated using EDX analysis and SEM images. A t-statistical analysis did not show a significant impact of TBM muck usage on the compressive strength results of the concrete mixes. However, another t-statistical analysis showed that TBM muck replacement of coarse aggregates had adversely affected the flexural strength results. The EDX analysis indicated the presence of Na+ ions, which can replace the Ca2+ ions in the C-S-H gel, cause discontinuities of it, and hence reduce the strength at later ages. Finally, the SEM images showed that the ettringite and carbon hydroxide (C-H) contents in the mixes with TBM muck were higher than that of the control mix, while the C-S-H gel was less in such mixes.

Chemical, morphological characterizations of Ririwai biotite and determination of yield point of its weighting agent application in drilling mud

Chemical, morphological characterizations and drilling mud yield point impact of Ririwai biotite have been investigated and reported in this work. Local Ririwai biotite mined in Doguwa Local Government Area of Kano State was used as a weighting agent in drilling mud formulation. Scanning Electron Microscopy (SEM) characterization, X-ray Diffraction (XRD) and Electron Dispersion X-ray (EDX) analysis of the Ririwai biotite were carried out. Water-based drilling mud was prepared using commercial bentonite according to the API 13A Standard. Effect of gradual addition of Ririwai weighting agent; 0 – 100 wt%, on the yield point of the formulated drilling mud was studied. XRD analysis showed that the dominant mineral phase in the material was biotite. Morphological analysis carried out showed that the Ririwai biotite had a sheet-like morphology while the commercial bentonite had clumpy morphology. The estimated average particle sizes were 60 and 25 μm for the Ririwai biotite and commercial bentonite, respectively. EDX analysis showed that silica-alumina ratio of the Ririwai biotite was 9.3 while that of the commercial bentonite was 1.58. The optimum yield point of the formulated drilling mud was 2.0 lb/100 ft2 corresponding to formulation having 0 – 30 wt% weighting agent composition. The specific gravity of Ririwai biotite was determined as 2.4.

Analysis of Ionic-Exchange of Selected Elements between Novel Nano-Hydroxyapatite-Silica Added Glass Ionomer Cement and Natural Teeth

One of the foremost missions in restorative dentistry is to discover a suitable material that can substitute lost and damaged tooth structure. To this date, most of the restorative materials utilized in dentistry are bio-inert. It is predicted that the addition of nano-HA-SiO2 to GIC matrix could produce a material with better ion-exchange between the restorative material and natural teeth. Therefore, the aim of the current study was to synthesize and investigate the transfer of specific elements (calcium, phosphorus, fluoride, silica, strontium, and alumina) between nano-hydroxyapatite-silica added GIC (nano-HA-SiO2-GIC) and human enamel and dentine. The novel nano-hydroxyapatite-silica (nano-HA-SiO2) was synthesized using one-pot sol-gel method and added to cGIC. Semi-quantitative energy dispersive X-ray (EDX) analysis was carried out to determine the elemental distribution of fluorine, silicon, phosphorus, calcium, strontium, and aluminum. Semi-quantitative energy dispersive X-ray (EDX) analysis was performed by collecting line-scans and dot-scans. The results of the current study seem to confirm the ionic exchange between nano-HA-SiO2-GIC and natural teeth, leading to the conclusion that increased remineralization may be possible with nano-HA-SiO2-GIC as compared to cGIC (Fuji IX).