Solid lipid nanoparticles for the delivery of anti-microbial oligonucleotides

Novel alternatives to antibiotics are urgently needed for the successful treatment of antimicrobial resistant (AMR) infections. Experimental antibacterial oligonucleotide therapeutics, such as transcription factor decoys (TFD), are a promising approach to circumvent AMR. However, the therapeutic potential of TFD is contingent upon the development of carriers that afford efficient DNA protection against nucleases and delivery of DNA to the target infection site. As a carrier for TFD, here we present three prototypes of anionic solid lipid nanoparticles that were coated with either the cationic bolaamphiphile 12-bistetrahydroacridinium or with protamine. Both compounds switched particles zeta potential to positive values, showing efficient complexation with TFD and demonstrable protection from deoxyribonuclease. The effective delivery of TFD into bacteria was confirmed by confocal microscopy while SLN-bacteria interactions were studied by flow cytometry. Antibacterial efficacy was confirmed using a model TFD targeting the Fur iron uptake pathway in E.coli under microaerobic conditions. Biocompatibility of TFDSLN was assessed using in vitro epithelial cell and in vivo Xenopus laevis embryo models. Taken together these results indicate that TFD-SLN complex can offer preferential accumulation of TFD in bacteria and represent a promising class of carriers for this experimental approach to tackling the worldwide AMR crisis

A novel hybrid aspirin-NO-releasing compound inhibits TNFalpha release from LPS-activated human monocytes and macrophages

<p>Abstract</p> <p>Background</p> <p>The cytoprotective nature of nitric oxide (NO) led to development of NO-aspirins in the hope of overcoming the gastric side-effects of aspirin. However, the NO moiety gives these hybrids potential for actions further to their aspirin-mediated anti-platelet and anti-inflammatory effects. Having previously shown that novel NO-aspirin hybrids containing a furoxan NO-releasing group have potent anti-platelet effects, here we investigate their anti-inflammatory properties. Here we examine their effects upon TNFα release from lipopolysaccharide (LPS)-stimulated human monocytes and monocyte-derived macrophages and investigate a potential mechanism of action through effects on LPS-stimulated nuclear factor-kappa B (NF-κB) activation.</p> <p>Methods</p> <p>Peripheral venous blood was drawn from the antecubital fossa of human volunteers. Mononuclear cells were isolated and cultured. The resultant differentiated macrophages were treated with pharmacologically relevant concentrations of either a furoxan-aspirin (B8, B7; 10 μM), their respective furazan NO-free counterparts (B16, B15; 10 μM), aspirin (10 μM), existing nitroaspirin (NCX4016; 10 μM), an NO donor (DEA/NO; 10 μM) or dexamethasone (1 μM), in the presence and absence of LPS (10 ng/ml; 4 h). Parallel experiments were conducted on undifferentiated fresh monocytes. Supernatants were assessed by specific ELISA for TNFα release and by lactate dehydrogenase (LDH) assay for cell necrosis. To assess NF-κB activation, the effects of the compounds on the loss of cytoplasmic inhibitor of NF-κB, IκBα (assessed by western blotting) and nuclear localisation (assessed by immunofluorescence) of the p65 subunit of NF-κB were determined.</p> <p>Results</p> <p>B8 significantly reduced TNFα release from LPS-treated macrophages to 36 ± 10% of the LPS control. B8 and B16 significantly inhibited monocyte TNFα release to 28 ± 5, and 49 ± 9% of control, respectively. The B8 effect was equivalent in magnitude to that of dexamethasone, but was not shared by 10 μM DEA/NO, B7, the furazans, aspirin or NCX4016. LDH assessment revealed none of the treatments caused significant cell lysis. LPS stimulated loss of cytoplasmic IκBα and nuclear translocation of the p65 NF-κB subunit was inhibited by the active NO-furoxans.</p> <p>Conclusion</p> <p>Here we show that furoxan-aspirin, B8, significantly reduces TNFα release from both monocytes and macrophages and suggest that inhibition of NF-κB activation is a likely mechanism for the effect. This anti-inflammatory action highlights a further therapeutic potential of drugs of this class.</p

Protein hunger of the feed sector: the alternatives offered by the plant world

The expected future demand for highly nutrient animal food products will push the animal production system to search for new sources of high-quality protein feedstuffs. In this scenario, economic and environmental issues will have to be considered while reducing the competition with the plant-based human food chains. Legume grains and some oilseed cakes, by-products from the oil industry, are the main protein sources for ruminants and terrestrial monogastrics such as pigs and poultry. Their relevant role will hold in the next decades, but it is necessary to increase the diversification of sources that can be grown profitably throughout the world, including European countries. Microalgae are a promising source of protein and other nutrients for animal feeding. However, an amazing richness of biologically active substances makes these organisms very interesting as feed ingredients, as their role go far beyond the supply of nutrients. Due to the limited usage of microalgae as human foodstuffs or food ingredients, low competition between microalgae-based feed and food chains is predictable. This review aims to synthesise current knowledge on minor pulses and other protein-rich plant products and microalgae, as alternative ingredients to the conventional animal protein sources, focussing on their production, availability, and nutritional values. Points of strength, weakness, opportunity and threat related to the use of these protein sources in animal feeding are separately analysed through a SWOT approach to underlie future needs in terms of research and/or technological development that could help valorise these nutrient sources as feed ingredients