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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 (NiFe2O4 MNPs) offer distinct advantages in both purification and immobilization of enzymes. In this work, we demonstrate the preparation of NiFe2O4 MNPs via a one-step solvothermal synthesis and their use in direct enzyme binding from cell lysates. These NiFe2O4 MNPs have showed an average diameter of 8.9 ± 1.7 nm from TEM analysis and a magnetization at saturation (Ms) 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 (BsGDH). 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 NiFe2O4 MNPs also showed similar activity to the purified free enzyme. By comparing on both carrier preparation and enzyme immobilization protocols, use of NiFe2O4 MNPs for direct enzyme immobilization from cell lysate can significantly reduce the number of steps, time, and use of chemicals. Therefore, NiFe2O4 MNPs can offer considerable advantages for use in both enzyme immobilization and protein purification in pharmaceutical and other chemical industries. [ABSTRACT FROM AUTHOR]

In this paper, we show a novel sustainable route for the production of sorption materials for carbon capture technologies by utilizing a general plastic waste. By supporting aminated poly(vinyl chloride) on mesoporous silicas, a family of polymer/silica composites was synthesized, characterized and tested gravimetrically for adsorption of CO2 from the 1 : 1 v/v CO2–N2 mixture. The composites show good adsorption capacity for CO2 peaking at 12 cm3 g−1 for ethylenediamine-treated PVC products on SBA-15 support. The adsorption efficiency (CO2 : N ratio) is comparable to those observed for other nanoporous materials, such as amine-grafted mesoporous silicas. Ethylenediamine was found to be the best aminating reagent for PVC as the composite prepared from EDA–PVC gave the highest CO2 adsorption efficiency. Moreover, contact angle measurements suggested a significant improvement in hydrophobicity of the selected composites when they were compared with the unfunctionalized silica supports. This very useful development could make the composites suitable for applications in elevated moisture content environments found in flue vapours of gas-fired power plants. [ABSTRACT FROM AUTHOR]

In this article, we report a new sustainable synthesis procedure for manufacturing chitosan/silica CO2 adsorbents. Chitosan is a naturally abundant material and contains amine functionality, which is essential for selective CO2 adsorptions. It is, therefore, ideally suited for manufacturing CO2 adsorbents on a large scale. By coating chitosan onto high-surface-area mesoporous silica supports, including commercial fumed silica (an economical and accessible reagent) and synthetic SBA-15 and MCF silicas, we have prepared a new family of CO2 adsorbents, which have been fully characterised with nitrogen adsorption isotherms, thermogravimetric analysis/differential scanning calorimetry, TEM, FTIR spectroscopy and Raman spectroscopy. These adsorbents have achieved a significant CO2 adsorption capacity of up to 0.98 mmol g−1 at ambient conditions ( P=1 atm and T=25 °C). The materials can also be fully regenerated/recycled on demand at temperatures as low as 75 °C with a >85 % retention of the adsorption capacity after 4 cycles, which makes them promising candidates for advanced CO2 capture, storage and utilisation technology. [ABSTRACT FROM AUTHOR]

Iron (II,III) oxide Fe3O4nanoparticles (25and 50 nm NPs) are grafted with amine groups through silanizationin order to generate a positively charged coating for binding negativelycharged species including DNA molecules. The spatial nature of thecoating changes from a 2-D-functionalized surface (monoamines) througha layer of amine oligomers (diethylenetriamine or DETA, about 1 nmin length) to a 3-D layer of polyamine (polyethyleneimine or PEI,thickness ≥3.5 nm). These Fe3O4–PEINPs were prepared by binding short-chain PEI polymers to the iodopropylgroups grafted on the NP surface. In this work, the surface chargedensity, or zeta potential, of the nanoparticles is found not to bethe only factor influencing the DNA binding capacity, which also seemsnot to be affected by their buffering capacity profile in the rangeof pH 4–10. This study also allows the investigation of this3-D effect on the surface of a nanoparticle as opposed to conventional2-D amine functionalization. The flexibility of the PEI coating, whichconsists of only 1, 2, and 3° amines, on the nanoparticle surfacehas a significant influence on the overall DNA binding capacity andthe binding efficiency (or N/P ratio). These polyamine-functionalizednanoparticles can be used in the purification of biomolecules andthe delivery of drugs and large biomolecules. [ABSTRACT FROM AUTHOR]

Aim: To analyze magnetic particle uptake and intracellular processing by the four main non-neuronal subclasses of the CNS: oligodendrocyte precursor cells; oligodendrocytes; astrocytes; and microglia. Materials & methods: Magnetic particle uptake and processing were studied in rat oligodendrocyte precursor cells and oligodendrocytes using fluorescence and transmission electron microscopy, and the results collated with previous data from rat microglia and astrocyte studies. All cells were derived from primary mixed glial cultures. Results: Significant intercellular differences were observed between glial subtypes: microglia demonstrate the most rapid/extensive particle uptake, followed by astrocytes, with oligodendrocyte precursor cells and oligodendrocytes showing significantly lower uptake. Ultrastructural analyses suggest that magnetic particles are extensively degraded in microglia, but relatively stable in other cells. Conclusion: Intercellular differences in particle uptake and handling exist between the major neuroglial subtypes. This has important implications for the utility of the magnetic particle platform for neurobiological applications including genetic modifcation, transplant cell labeling and biomolecule delivery to mixed CNS cell populations. [ABSTRACT FROM AUTHOR]