الفهرس 
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Abstract
ABSTRACT
Nosocomial infections remain one of the leading causes of morbidity and mortality worldwide. The WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. Therefore, the antibiotic resistance crisis is one of the most pressing issues in global public health. Associated with the rise in antibiotic resistance is the lack of new antimicrobials. This has triggered initiatives worldwide to develop novel and more effective antimicrobial compounds as well as to develop novel delivery and targeting strategies. Different strategies, such as the use of nanostructured materials, are being developed to overcome these and other types of resistance. Nanostructured materials can be used to convey antimicrobials, to assist in the delivery of novel drugs or ultimately, possess antimicrobial activity by themselves. Additionally, nanoparticles (e.g., metallic, organic, carbon nanotubes, etc.) may circumvent drug resistance mechanisms in bacteria and, associated with their antimicrobial potential, inhibit biofilm formation or other important processes. Other strategies, including the combined use of polymers and nanoparticles to increase the efficacy and overcome toxicity issues, are also being investigated. Coupling nanoparticles and polymerers (or other repurposed compounds) to inhibit the activity of bacterial efflux pumps; formation of biofilms; interference of quorum sensing; and possibly plasmid curing, are just some of the strategies to combat multidrug resistant bacteria. However, the use of nanoparticles still presents a challenge to therapy and much more research is needed in order to overcome this. We will summarize the current research on nanoparticles and other nanomaterial and how these are or can be applied in the future to fight multidrug resistant bacteria.
Resistance in bacteria can be overcome only by the intelligent and practical deployment of nanotechnology. Antibacterial resistance has cleared the path for more effective and sensitive ways for detecting and treating bacterial infections because to Nanotechnology. These Nano-composites have been utilized with molecular beacons to determine bactericidal actions, target medication delivery, and anti-fouling coatings, among other purposes. More recent approaches to improving efficacy against MDR bacteria, such as combining more than one nanoparticle with polymer (Nano-composites), have also been summarized. Nano-composite may be used to fight multidrug-resistant bacteria in a novel way, according to our findings.
Ag2o-60P2O5–20CaO–20Na2O and Ag2o-60P2O5–30CaO–10Na2O nanoparticles are synthesized and simultaneously deposited on cotton fabric using ultrasound irradiation. The optimization of the processing conditions, the specific reagent ratio, and the precursor concentration results in the formation of uniform nanoparticles with an average size of ≈30 nm. The antibacterial activity of the Ag2o-60P2O5–20CaO–20Na2O and Ag2o-60P2O5–30CaO–10Na2O in a colloidal suspension or deposited on the fabric is tested against Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive) bacteria and other multidrug resistant bacteria. A substantial enhancement of 10 000 times in the antimicrobial activity of the Nano- composite compared to the pure nanoparticles (NPs) is observed after 10 min exposure to the bacteria. Finally, the mechanism for this enhanced antibacterial activity is presented.
Nanocomposites are found in nature, for example in the structure of the abalone shell and bone. The use of nanoparticle-rich materials long predates the understanding of the physical and chemical nature of these materials. Jose-Yacaman et al. investigated the origin of the depth of colour and the resistance to acids and bio-corrosion of Maya blue paint, attributing it to a nanoparticle mechanism. from the mid-1950s nanoscale organo-clays have been used to control flow of polymer solutions (e.g. as paint viscosifiers) or the constitution of gels (e.g. as a thickening substance in cosmetics, keeping the preparations in homogeneous form). By the 1970s polymer/clay composites were the topic of textbooks, although the term ”nanocomposites” was not in common use. In mechanical terms, nanocomposites differ from conventional composite materials due to the exceptionally high surface to volume ratio of the reinforcing phase and/or its exceptionally high aspect ratio. The reinforcing material can be made up of particles (e.g. minerals), sheets (e.g. exfoliated clay stacks) or fibres (e.g. carbon nanotubes or electrospun fibres). The area of the interface between the matrix and reinforcement phase(s) is typically an order of magnitude greater than for conventional composite materials. The matrix material properties are significantly affected in the vicinity of the reinforcement. Ajayan et al. note that with polymer nanocomposites, properties related to local chemistry, degree of thermoset cure, polymer chain mobility, polymer chain conformation, degree of polymer chain ordering or crystallinity can all vary significantly and continuously from the interface with the reinforcement into the bulk of the matrix.
This large amount of reinforcement surface area means that a relatively small amount of nanoscale reinforcement can have an observable effect on the macroscale properties of the composite. For example, adding carbon nanotubes improves the electrical and thermal conductivity. Other kinds of nanoparticulates may result in enhanced optical properties, dielectric properties, heat resistance or mechanical properties such as stiffness, strength and resistance to wear and damage. In general, the nano reinforcement is dispersed into the matrix during processing. The percentage by weight (called mass fraction) of the nanoparticulates introduced can remain very low (on the order of 0.5% to 5%) due to the low filler percolation threshold, especially for the most commonly used non-spherical, high aspect ratio fillers (e.g. nanometer-thin platelets, such as clays, or nanometer-diameter cylinders, such as carbon nanotubes). The orientation and arrangement of asymmetric nanoparticles, thermal property mismatch at the interface, interface density per unit volume of nanocomposite, and polydispersity of nanoparticles significantly affect the effective thermal conductivity of nanocomposites.
Antimicrobial nano textiles are prepared by coating or deposition of the biocides such as organic compounds or nanoparticles on the textile fibers. The deposition of silver nanoparticles (AgNPs) on textiles has received increased attention due to their well-known antimicrobial properties. Recently, the technique of in situ synthesis and deposition of AgNPs on cotton is being used frequently to prepare antimicrobial nanotextiles. The technique involves complexation of the Ag+ ions in cotton fibers followed by their reduction to generate the particles. This in situ synthesis and deposition approach provides several advantages over the post synthesis deposition or grafting process. In this brief overview, we have presented basic information about different biocides used to prepare antimicrobial nanotextiles and highlighted the importance of in situ synthesis and deposition of AgNPs on cotton to prepare the antimicrobial nano textiles. The recent achievements in this field and future challenges that need to be addressed are presented.
posites CSNCs derived from copper hexacyanoferrate CHCF with copolymer of anthranilic acid with ortho aminophenol poly(AA-co-o-AP) and copolymer of anthranilic acid with ortho phenylenediamine poly(AA-co-o-PD) were synthesized by redox polymerization using ammonium peroxydisulfate (APS) as an oxidant.
The synthesis route included (i) synthesis of nanoparticles of CHCF (ii) plantation the nanocomposites core shell in polymer matrix of poly(AA-co-o-AP) and poly(AA-co-o-PD) during the copolymerization process.
The structures of the prepared CSNCs are confirmed via FT-IR, X-ray powder diffraction (XRD) and Thermogravimetric (TGA), TEM and SEM–EDX mapping. The SEM and TEM confirmed the nano structures of the prepared CHCF and CSNCs. Also, XRD analysis confirmed the expansion of the CHCF into poly(AA-co-o-AP) and poly(AA-co- o-PD). The surface area of CSNC was determined also by Brunauer-Emmett-Teller (BET).
The synthesized CSNCs used for sorption of cesium ions from aqueous solutions by ion exchange process between the potassium ions in CSNCs replaced by cesium ions. FTIR analysis confirmed the presence of CN bonds in the CSNCs adsorbents implying the successful plantation of CHCF on the copolymers, which was further supported by EDX mapping. The sorption process of the synthesized CSNCs towards cesium ions and the factors affecting on the cesium sorption from aqueous solutions were reported at the difference in pH, metal ion concentration, shaking time and temperature for the two core shell nanocomposites. Four modeling include on Langmuir, Freundlich, Temkin and Dubinin-Radushkevich
(D-R) isotherms models were studied, which the data were well fitted with Langmuir model suggesting that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics results were fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature range of 25-60 °C and the data revealed that Cs+ sorption was endothermic, spontaneous, and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl for the synthesized core shell nanocomposites CSNCs derived from copper hexacyanoferrate CHCF with copolymer of anthranilic acid with o-aminophenol poly(AA-co-o-AP) and copolymer of anthranilic acid with o-phenylenediamine poly(AA-co-o-PD).