Functionalisation of commercial chicken soup with enriched polyphenol extract from vegetable by-products

Ready-to-eat foods such as soups are in great demand by consumers, owing to the changes in lifestyle over the last half-century. In this context, the addition of new health-promoting active ingredients such as polyphenols could represent an important way to increase the intake of these compounds. Three different by-products from artichoke, lettuce and cauliflower handling and commercialisation have been use to obtain enriched polyphenol extract using a water extraction protocol. The artichoke by-products extract was composed of caffeic acid derivatives while the lettuce and the cauliflower by-products extract were composed of both caffeic acid derivatives and flavonols. The amounts of these compounds were evaluated with HPLC-DAD; it transpired that the artichoke by-products extract had the highest levels of polyphenols (100 mg of polyphenols/g of dry extract), followed by lettuce by-products extract (46 mg of polyphenols/g of dry extract) and cauliflower by-products extract (34 mg of polyphenols/g of dry extract). A sensory panel with four trained judges evaluated the addition of different amounts of extracts. Both artichoke and lettuce by-products extract could be added to the soup to a maximum amount of 10 mg of extract/mL of soup and cauliflower with 5 mg of extract/mL of soup, while still improving the grade of acceptability of the soup with respect to the original soup. In addition, antioxidant capacity was evaluated as free radical scavenging activity (ABTS^·+ assay) and the ability to reduce the 2,4,6-tripyridyl-s-triazine (TPTZ)-Fe(III) complex to TPTZ-Fe(II) (FRAP assay). The antioxidative capacity increased with addition of the extracts between 3.5 times and 13 times (ABTS^·+ assay) as well as between 23 times and 85 times (FRAP assay). The results obtained indicate that these by-products could provide the extracts with antioxidant phenolics that could be used to functionalise foods. Obviously, before incorporating these by-product extracts as dietary complements, it is necessary to carry out further studies about their toxicity (i.e. possible residual presence of pesticides), in vivo activity, and bioavailability.     

Functionalised exposed building materials: Self-cleaning,photocatalytic and biofouling abilities

With the advent of urbanisation, there was a considerable and progressive worsening of urban air quality. Amongst the solutions proposed by scientific research, photocatalysis proved itself to be one of the most promising. In the present work, commercial glazed ceramic tiles were functionalised with a micrometric TiO₂ layer adopting an industrial-like process. It was purposely chosen to avoid the use of nanoparticles because they might be inhaled and come into direct contact with the cells of the human organism during the industrial processing. Additionally, the self-cleaning, photocatalytic – the former by means of liquid-solid phase photocatalytic tests and water contact angle measurements; the latter against nitrogen oxides abatement – and biofouling abilities of the functionalised materials were thoroughly investigated. Results showed that the functionalised glazed ceramic tile possessed excellent self-cleaning and photocatalytic properties. As per the algal growth, surface roughness showed itself to be a key-point: the TiO₂ surface layer, giving the material a higher surface roughness compared to the untreated one, had an accelerated algal growth process.     

Water-soluble fullerenes for medical applications

Research on fullerenes occupies a unique position in the scientific arena. Synthesis and characterisation of this nanomaterial blur the line between materials science and chemistry; careful tuning of the processing methods gives birth to a whole family of molecules and their functionalised derivatives, whose unusual properties at this nanoscopic scale can be exploited in cutting-edge technological applications. This review focuses on the functionalisation of fullerenes for use in medical applications. The first half gives an introduction to the fullerenes themselves and how their fundamental properties lead to a very rich chemistry, enabling both exohedral (external) and endohedral (internal) functionalisations of the cage. Emphasis is placed on the need for safe and reproducible synthesis routes if fullerenes are ever going to make it to the pharmaceutical market. In line with this, a selection of exohedral functionalisation protocols receives particular attention. Coverage of endohedral fullerene synthesis routes is limited to the endohedral metallofullerenes. In the second half, myriad applications of fullerenes in biomedical contexts are introduced and certain synthesis routes are critically evaluated. Discussion of the need to water solubilise the hydrophobic fullerene cages precedes an overview of fullerene-based diagnostic and therapeutic technologies. A final moment is spent on toxicity studies of fullerenes. The concluding remarks emphasise the positive effects of incorporating fullerenes into biomedical technologies, while looking at how these are perceived by the general public. A case is made for fullerenes being the optimal choice as standard bearers in the advance of nanomaterials into the medical field.

This is the winning review of the 2016 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining, run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged.     

Large pore bi-functionalised mesoporous silica for metal ion pollution treatment

Here we demonstrate aminopropyl and mercatopropyl functionalised and bi-functionalised large pore mesoporous silica spheres to extract various metal ions from aqueous solutions towards providing active sorbents for mitigation of metal ion pollution. Elemental analysis (EA) and FTIR techniques were used to quantify the attachment of the aminopropyl and mercatopropyl functional groups to the mesoporous silica pore wall. Functionalisation was achieved by post-synthesis reflux procedures. For all functionalised silicas the functionalisation refluxing does not alter particle morphology/agglomeration of the particles. It was found that sorptive capacities of the mesoporous silica towards the functional groups were unaffected by co-functionalisation. Powder X-ray diffraction (PXRD) and nitrogen adsorption techniques were used to establish the pore diameters, packing of the pores and specific surface areas of the modified mesoporous silica spheres. Atomic absorption (AA) spectroscopy and inductively coupled plasma-atomic emission spectrometry (ICP-AES) techniques were used to measure the extraction efficiencies of each metal ion species from solution at varying pHs. Maximum sorptive capacities (as metal ions) were determined to be 384micromolg(-1) for Cr, 340micromol g(-1) for Ni, 358micromol g(-1) for Fe, 364micromol g(-1) for Mn and 188micromol g(-1) for Pd.     

Temperature insensitive conductance detection with surface-functionalised silicon nanowire sensors

The effects of suspension and functionalisation on electrical conduction of silicon nanowires (SiNWs) are experimentally investigated towards highly sensitive chemical and biological detection applications. The conductance is found to be affected by the suspension process, while it shows the similar trend against the temperature before and after the suspension. The reduction of conductance after the functionalisation with NH₂ self-assembled monolayer/glutaraldehyde/biotin can be explained based on the assumption that there is a charge transfer from the SiNW to the molecular layers. The temperature insensitive conductance found in the functionalised SiNWs experimentally for the first time is expected to be extremely useful for practical sensing applications.     

Membrane emulsification for the production of uniform poly-N-isopropylacrylamide-coated alginate particles using internal gelation

Alginate particles, crosslinked by calcium ions, have a number of potential biopharmaceutical industry applications due to the biocompatibility of the materials used and formed. One such use is as microcarriers for cell attachment, growth and then detachment without the use of proteolytic enzymes. A straightforward and reproducible method for producing uniform calcium alginate particles with controllable median diameters which employs membrane emulsification and internal gelation (solid particles contained in the dispersed phase) is demonstrated, as well as functionalisation of the resulting beads with amine terminated poly N-isopropylacrylamide (pNIPAM) to form temperature responsive particles, by taking advantage of the electrostatic interaction between the carboxyl groups of the alginate and amino groups of the modified pNIPAM. Cell attachment, growth and detachment capabilities of these core–shell structures were assessed and successfully demonstrated by using phase contrast microscopy and fluorescent staining with calcein-AM and ethidium homodimer-1.