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Functionalized aerogels and xerogels are demonstrated for use in the removal of contaminants from aqueous and gaseous streams, including species such as halides, noble gases, actinides, lanthanides, alkalis, and alkaline earths that could pose environmental and health concerns if not captured and contained properly. In article number 2000013 Brian J. Riley and co‐workers provides a progress report of the current state of the art in this area.

Several different types of aerogels and xerogels are demonstrated as effective sorbents for the capture and/or immobilization of radionuclides and other contaminants in gaseous form [e.g., Hg(g), I2(g), Xe, Kr] as well as ionic form (e.g., Cd2+, Ce4+, Cs+, Cu2+, Fe2+, Hg2+, I−, IO3−, Kr, Pb2+, Rb+, Sr2+, 99Tc7+, U6+, Zn2+). These sorbents have unique properties, which include high specific surface areas, high pore volumes, a range of pore sizes, and functionalities that provide methods for binding radionuclides and other contaminants, generally through physisorption, chemisorption, or a combination thereof. This combination of properties and functionalities makes these types of materials ideal for use as sorbents for capturing radionuclides. The primary base materials that will be discussed in this paper include Ag0‐functionalized silica aerogels, Ag+‐impregnated aluminosilicate aerogels, Ag0‐functionalized aluminosilicate aerogels, metal‐impregnated (non‐Ag) aluminosilicate aerogels and xerogels, sulfide‐based aerogels, and carbon‐based aerogel composites. For the capture of I2(g), the materials reported herein show some of the highest iodine loadings ever reported for inorganic sorbents. For the capture of ionic species, these materials also show promise as next‐generation materials for active radionuclide remediation. This progress report describes materials fabrication, general properties, and environmental remediation applications. Functionalized aerogels and xerogels are demonstrated for use in the removal of contaminants from aqueous and gaseous streams, including species such as halides, noble gases, actinides, lanthanides, alkalis, and alkaline earths that could pose environmental and health concerns if not captured and contained properly. This paper provides a progress report of the current state of the art in this area.

Metal nanoparticle‐based spherical nucleic acids (SNAs) have been widely used in various fields, such as imaging and biosensing. However, functionalizing nanoparticles with specific properties, such as high DNA density or the attachment of long oligonucleotides, can be challenging. Choosing the ideal strategy is essential, as each functionalization method yields distinct results and has its limitations. In this study, four functionalization techniques — salt‐aging, pH‐assisted, freezing‐directed, and microwave (MW)‐assisted methods are investigated — for modifying silver nanoparticles (AgNPs), focusing on thymine‐strands (T‐strands) of varying lengths. The resulting DNA‐AgNP conjugates are characterized using UV/Vis spectroscopy and dynamic light scattering (DLS), and colloidal stability and DNA loading are assessed. The reagent‐free freezing‐directed and MW‐assisted methods follow a straightforward implementation. Generally, they result in higher DNA loading than salt‐aging and pH‐assisted methods, particularly when functionalizing with longer strands. However, these methods require higher DNA excess for shorter strand lengths and thus cannot be used to synthesize conjugates with low DNA densities. The different properties of each functionalization method can be exploited to construct various AgNP‐based SNAs with distinct specifications. The findings provide a methodological user guide to facilitate the selection of the most suitable functionalization strategy, thereby extending their utility in various nanobiotechnological applications. This study evaluates four functionalization methods—salt‐aging, pH‐assisted, freezing‐directed, and microwave‐assisted—for attaching DNA strands to 20 nm silver nanoparticles (AgNPs). The resulting DNA‐AgNP conjugates are characterized and colloidal stability and DNA loading are assessed. The findings offer practical guidance for selecting the most effective strategy to construct tailored AgNP‐based spherical nucleic acids (SNAs) for diverse nanobiotechnology applications.

BackgroundNanoparticles have a large number of surface atoms, which translates into a significant increase in the surface energy. Once introduced in a biological environment they tend to interact with proteins and form a protein corona shell. The aim of this study was to develop a novel, silver based, bio-nanocomposite for biological applications. Immunoglobulin G (IgG) molecule was chosen for the passivation of the silver nanoparticles (AgNPs) in order to avoid macrophage recognition of the synthesized structures.ResultsMonodisperse IgG-folinate functionalized silver nanoparticles were obtained, with sizes around 39 nm. UV–Vis and UATR-FT-IR spectroscopies were employed to confirm the successful functionalization of the silver nanoparticles. Atomic force microscopy and dynamic light scattering measurements gave information about the size and shape of the nanoparticles prior and after the passivation with IgG.ConclusionsImmunoglobulin G formed a monolayer around the nanoparticles with the binding site seemingly in the Fc domain, leaving the two Fab regions available for antigen binding. To our knowledge, this is the first report of an IgG-folinate functionalized AgNP bionanostructure developed for biological applications.

Silver nanoparticles have been intensively studied over a long period of time because they exhibit antibacterial properties in infection treatments, wound healing, or drug delivery systems. The advantages that silver nanoparticles offer regarding the functionalization confer prolonged stability and make them suitable for biomedical applications. Apart from functionalization, silver nanoparticles exhibit various shapes and sizes depending on the conditions used through their fabrications and depending on their final purpose. This paper presents a review of silver nanoparticles with respect to synthesis procedures, including the polluting green synthesis. Currently, the most commonly used characterization techniques required for nanoparticles investigation in antibacterial treatments are described briefly, since silver nanoparticles possess differences in their structure or morphology.

N-heterocyclic carbene (NHC) silver(I) and gold(I) complexes have found different applications in various research fields, as in medicinal chemistry for their antiproliferative, anticancer, and antibacterial activity, and in chemistry as innovative and effective catalysts. The possibility of modulating the physicochemical properties, by acting on their ligands and substituents, makes them versatile tools for the development of novel metal-based compounds, mostly as anticancer compounds. As it is known, chemotherapy is commonly adopted for the clinical treatment of different cancers, even though its efficacy is hampered by several factors. Thus, the development of more effective and less toxic drugs is still an urgent need. Herein, we reported the synthesis and characterization of new silver(I) and gold(I) complexes stabilized by caffeine-derived NHC ligands, together with their biological and catalytic activities. Our data highlight the interesting properties of this series as effective catalysts in A3-coupling and hydroamination reactions and as promising anticancer, anti-inflammatory, and antioxidant agents. The ability of these complexes in regulating different pathological aspects, and often co-promoting causes, of cancer makes them ideal leads to be further structurally functionalized and investigated.

Photo-grafting is a gentle, simple, and precise approach to incorporating specific functional molecules for the surface functionalization of substrates. In this work, ultraviolet (UV)-induced tannic acid (TA) grafting onto the surface of bamboo was proposed as a viable strategy for functionalizing bamboo. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) clearly indicated that TA was successfully introduced to the bamboo’s surface. The optimal conditions for the grafting reaction were determined to be 15 mM Methyl-2-benzoylbenzoate (BB), 30 mM TA, 20 min, and a pH = 8. Under these conditions, the amount of TA grafted onto the bamboo’s surface was measured to be 19.98 μg/cm2. Results from Inductively Coupled Plasma (ICP) and Energy Dispersive Spectrometer (EDS) analyses showed that the silver ion loading capacity of tannic acid-grafted bamboo was significantly improved compared to that of raw bamboo and tannic acid-impregnated bamboo. Furthermore, the presence of TA grafted on the bamboo’s surface exhibited a positive correlation with the loading of silver ions, indicating that grafted TA plays an important role in the surface functionalization of bamboo. We believe that photo-grafted TA may help generate multifunctional bamboo with diverse properties.

In this work, functionalized reduced graphene oxide–silver (FrGO–Ag) nanocomposite was synthesized to enhance the antimicrobial activity and biocompatibility of FrGO for infected wound burn treatment. The reduction of GO and FGO was confirmed by the removal of some of the oxygen functional groups (carbonyl and epoxy groups) as revealed by Fourier transform infrared (FTIR) spectra. The face-centered cubic (fcc) silver nanoparticles were identified by X-ray diffraction (XRD). The contact time effect and the dose effect of the antimicrobial activity of rGO, FrGO, and FrGO-Ag nanocomposite toward Staphylococcus aureus , Pseudomonas aeruginosa and Candida albicans have been investigated. The cytotoxicity results of these compounds revealed that the functionalization by PVP and the decoration by AgNPs improved the biocompatibility of rGO sheets from 35.2 to 88% cell viability against the BJ1 normal human epithelial cell line. Graphical Abstract

Reverse osmosis (RO) is the most common method for treating salt and brackish water. As a membrane‐driven process, a key challenge for RO systems is their susceptibility to scaling and biofouling. To address these issues, functional coatings utilizing metal nanoparticles (MNPs) are developed. In this study, silver, gold, and copper nanoparticles are applied onto thin‐film composite (TFC) membranes using plasma‐enhanced magnetron sputtering. The elemental composition, surface morphology, and hydrophilicity of the coatings are analyzed using X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurements. The antimicrobial properties and the filtration efficiency of the coated membranes are assessed through application‐specific experimental setups. Silver and copper nanoparticles exhibit superior antimicrobial properties, reducing microorganism adhesion by a factor of 103 compared to uncoated membranes. Under appropriate coating conditions, no deterioration in filtration performance is observed. Enhancing the adhesion of MNPs is necessary for achieving sustained release of metal ions. This study investigates the use of plasma‐enhanced magnetron sputtering for applying biofunctional MNP coatings to RO composite membranes. Application‐oriented laboratory tests demonstrate that silver and copper nanoparticle coatings can be applied via vacuum‐based processes without compromising membrane performance while providing excellent antimicrobial properties.

Titanium implantation success may be compromised by Staphylococcus aureus surface colonization and posterior infection. To avoid this issue, different strategies have been investigated to promote an antibacterial character to titanium. In this work, two antibacterial agents (silver nanoparticles and a multifunctional antimicrobial peptide) were used to coat titanium surfaces. The modulation of the nanoparticle (≈32.1 ± 9.4 nm) density on titanium could be optimized, and a sequential functionalization with both agents was achieved through a two-step functionalization method by means of surface silanization. The antibacterial character of the coating agents was assessed individually as well as combined. The results have shown that a reduction in bacteria after 4 h of incubation can be achieved on all the coated surfaces. After 24 h of incubation, however, the individual antimicrobial peptide coating was more effective than the silver nanoparticles or their combination against Staphylococcus aureus. All tested coatings were non-cytotoxic for eukaryotic cells.