Carbon capture and storage (CCS) technologies aiming at tackling CO2 emission have attracted much attention from scientists of various backgrounds. Most CCS systems require an efficient adsorbent to ...remove CO2 from sources such as fossil fuels (pre‐combustion) or flue gas from power generation (post‐combustion). Research on developing efficient adsorbents with a substantial capacity, good stability and recyclability has grown rapidly in the past decade. Because of their high surface area, highly porous structure, and high stability, various nanoporous materials have been viewed as good candidates for this challenging task. Here, recent developments in several classes of nanoporous materials, such as zeolites, metal organic frameworks (MOFs), mesoporous silicas, carbon nanotubes, and organic cage frameworks, for CCS are examined and potential future directions for CCS technology are discussed. The main criteria for a sustainable CO2 adsorbent for industrial use are also rationalized. Moreover, catalytic transformations of CO2 to other chemical species using nanoporous catalysts and their potential for large scale carbon capture and utilization (CCU) processes are also discussed. Application of CCU technologies avoids any potential hazard associated with CO2 reservoirs and allows possible recovery of some running cost for CO2 capture by manufacturing valuable chemicals.
Nanoporous materials have shown great potential as efficient adsorbents for carbon capture and storage (CCS) technologies. An overview of the properties of these classes of nanomaterials with their advantages and limitations regarding use as CO2 adsorbents is presented. New research directions in CO2 utilization are also discussed.
Magnetic nanoparticles for gene and drug delivery McBain, Stuart C; Yiu, Humphrey H P; Dobson, Jon
International Journal of Nanomedicine,
01/2008, Letnik:
3, Številka:
2
Journal Article, Book Review
Recenzirano
Odprti dostop
Investigations of magnetic micro- and nanoparticles for targeted drug delivery began over 30 years ago. Since that time, major progress has been made in particle design and synthesis techniques, ...however, very few clinical trials have taken place. Here we review advances in magnetic nanoparticle design, in vitro and animal experiments with magnetic nanoparticle-based drug and gene delivery, and clinical trials of drug targeting.
Enzymatic reduction using oxidoreductases is important in commercial chemical production. This enzymatic action requires a cofactor (e.g., NADH) as a hydrogen source that is consumed during reaction ...and must be regenerated. We present, for the first time, an in situ NADH regeneration (NAD+ → NADH) using a heterogeneous catalyst (Pt/Al2O3) and H2 coupled with an enzymatic reduction. This regeneration system can be operated at ambient pressure where NADH yield and turnover frequency (TOF) increased with temperature (20–37 °C) and pH (4.0–9.9) delivering full selectivity to enzymatically active NADH. Cofactor regeneration by heterogeneous catalysis represents a cleaner (H+ as sole byproduct) alternative to current enzymatic and homogeneous (electro- and photo-) catalytic methods with the added benefit of facile catalyst separation. The viability of coupling cofactor regeneration with enzymatic (alcohol dehydrogenase, ADH) reaction is established in aldehyde reduction (propanal to propanol) where 100% alcohol yield was achieved. The potential of this hybrid inorganic–enzymatic system is further demonstrated in the continuous (fed-batch) conversion of propanal with catalyst (activity/selectivity) stability for up to 100 h.
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•Magnetic MIP networks were synthesized via microemulsion polymerization in presence of vinyl-MNPs.•MMIPs show high selectivity in binding template antibiotics.•MMIPs can be recovered ...using a magnet and recycled.
Adverse effects of pharmaceutical emerging contaminants (PECs), including antibiotics, in water supplies has been a global concern in recent years as they threaten fresh water security and lead to serious health problems to human, wildlife and the environment. However, detection of these contaminants in water sources, as well as food products, is difficult due to their low concentration. Here, we prepared a new family of magnetic molecular imprinted polymer (MMIP) networks for binding antibiotics via a microemulsion polymerization technique using vinyl silane modified Fe3O4 magnetic nanoparticles. The cross-linked polymer backbone successfully integrated with 20−30 nm magnetic nanoparticles and generated a novel porous polymeric network structure. These networks showed a high binding capacity for both templates, erythromycin and ciprofloxacin at 70 and 32 mg/g. Both MMIPs were also recyclable, retaining 75 % and 68 % of the binding capacity after 4 cycles. These MMIPs have showed a clear preference for binding the template molecules, with a binding capacity 4- to 7-fold higher than the other antibiotics in the same matrix. These results demonstrate our MMIP networks, which offered high binding capacity and selectivity as well as recyclability, can be used for both removal and monitoring hazardous antibiotic pollutants in different sources/samples and food products.
Abstract
Purification of valuable engineered proteins and enzymes can be laborious, costly, and generating large amount of chemical waste. Whilst enzyme immobilization can enhance recycling and reuse ...of enzymes, conventional methods for immobilizing engineered enzymes from purified samples are also inefficient with multiple-step protocols, regarding both the carrier preparation and enzyme binding. Nickel ferrite magnetic nanoparticles (NiFe
2
O
4
MNPs) offer distinct advantages in both purification and immobilization of enzymes. In this work, we demonstrate the preparation of NiFe
2
O
4
MNPs via a one-step solvothermal synthesis and their use in direct enzyme binding from cell lysates. These NiFe
2
O
4
MNPs have showed an average diameter of 8.9 ± 1.7 nm from TEM analysis and a magnetization at saturation (M
s
) value of 53.0 emu g
–1
from SQUID measurement. The nickel binding sites of the MNP surface allow direct binding of three his-tagged enzymes,
d
-phenylglycine aminotransferase (
d
-PhgAT),
Halomonas elongata
ω-transaminase (HeωT), and glucose dehydrogenase from
Bacillus subtilis
(
Bs
GDH). It was found that the enzymatic activities of all immobilized samples directly prepared from cell lysates were comparable to those prepared from the conventional immobilization method using purified enzymes. Remarkably,
d
-PhgAT supported on NiFe
2
O
4
MNPs also showed similar activity to the purified free enzyme. By comparing on both carrier preparation and enzyme immobilization protocols, use of NiFe
2
O
4
MNPs for direct enzyme immobilization from cell lysate can significantly reduce the number of steps, time, and use of chemicals. Therefore, NiFe
2
O
4
MNPs can offer considerable advantages for use in both enzyme immobilization and protein purification in pharmaceutical and other chemical industries.
This study explored the synergistic effects of simultaneously using calcium and gallium cations in the cross-linking of alginate, detailing its effects on the characteristics of alginate compared to ...its single cation counterparts. The primary goal is to determine if there are any synergistic effects associated with the utilisation of multiple multivalent cations in polymer cross-linking and whether or not it could therefore be used in pharmaceutical applications such as wound healing. Given the fact divalent and trivalent cations have never been utilised together for cross-linking, an explanation for the mode of binding that occurs between the alginate and the cations during the cross-linking process and how it may affect the future applications of the polymer has been investigated. The calcium gallium alginate polymers were able to retain the antibacterial effects of gallium within the confines of the polymer matrix, possessing superior rheological properties, 6 times that of pure calcium and pure gallium, coupled with an improved swelling capacity that is 4 times higher than that of gallium alginate.
The use of simulated biological fluids (SBFs) is a promising in vitro technique to better understand the release mechanisms and possible in vivo behaviour of materials, including fibres, ...metal-containing particles and nanomaterials. Applications of SBFs in dissolution tests allow a measure of material biopersistence or, conversely, bioaccessibility that in turn can provide a useful inference of a materials biodistribution, its acute and long-term toxicity, as well as its pathogenicity. Given the wide range of SBFs reported in the literature, a review was conducted, with a focus on fluids used to replicate environments that may be encountered upon material inhalation, including extracellular and intracellular compartments. The review aims to identify when a fluid design can replicate realistic biological conditions, demonstrate operation validation, and/or provide robustness and reproducibility. The studies examined highlight simulated lung fluids (SLFs) that have been shown to suitably replicate physiological conditions, and identify specific components that play a pivotal role in dissolution mechanisms and biological activity; including organic molecules, redox-active species and chelating agents. Material dissolution was not always driven by pH, and likewise not only driven by SLF composition; specific materials and formulations correspond to specific dissolution mechanisms. It is recommended that SLF developments focus on biological predictivity and if not practical, on better biological mimicry, as such an approach ensures results are more likely to reflect in vivo behaviour regardless of the material under investigation.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Surface engineering to control cell behavior is of high interest across the chemical engineering, drug delivery and biomaterial communities. Defined chemical strategies are necessary to tailor ...nanoscale protein interactions/adsorption, enabling control of cell behaviors for development of novel therapeutic strategies. Nanoparticle-based therapies benefit from such strategies but particle targeting to sites of neurological injury remains challenging due to circulatory immune clearance. As a strategy to overcome this barrier, the use of stealth coatings can reduce immune clearance and prolong circulatory times, thereby enhancing therapeutic capacity. Polyethylene glycol (PEG) is the most widely-used stealth coating and facilitates particle accumulation in the brain. However, once within the brain, the mode of handling of PEGylated particles by the resident immune cells of the brain itself (the ‘microglia’) is unknown. This is a critical question as it is well established that microglia avidly sequester nanoparticles, limiting their bioavailability and posing a major translational barrier. If PEGylation can be proved to promote evasion of microglia, then this information will be of high value in developing tailored nanoparticle-based therapies for neurological applications. Here, we have conducted the first comparative study of uptake of PEGylated particles by all the major (immune and non-immune) brain cell types. We prove for the first time that PEGylated nanoparticles evade major brain cell populations — a phenomenon which will enhance extracellular bioavailability. We demonstrate changes in protein coronas around these particles within biological media, and discuss how surface chemistry presentation may affect this process and subsequent cellular interactions.
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