Bi-modal confirmation of liposome delivery to the brain after focused ultrasound-induced blood-brain barrier opening.

Focused ultrasound-mediated opening of the blood-brain barrier offers a great opportunity to deliver therapeutics into hard-to-treat brain tumors such as glioblastoma multiforme or diffuse midline glioma. However, the potential of the technique to offer a time window for efficient nanomedicine delivery has not been thoroughly studied. Non-invasive and targeted delivery of large drug-loaded nanocarriers, such as liposomes, could offer a safe and scalable method of personalized therapy for the treatment of brain pathologies.

Effect of Phase-Change Nanodroplets and Ultrasound on Blood-Brain Barrier Permeability In Vitro.

Phase-change nanodroplets (PCND;NDs) are emulsions with a perfluorocarbon (PFC) core that undergo acoustic vaporisation as a response to ultrasound (US). Nanodroplets change to microbubbles and cavitate while under the effect of US. This cavitation can apply forces on cell connections in biological barrier membranes, such as the blood-brain barrier (BBB), and trigger a transient and reversible increased permeability to molecules and matter.

Self-Organization of Lipid-Porphyrin Conjugates at the Air/Water Interface.

Lipid-porphyrin conjugates are versatile compounds which can self-assemble into liposome-like structures with multifunctional properties. Most of the conjugates that have been described so far, consisted in grafting pyropheophorbide-a (Pyro-a) or other porphyrin derivatives through the esterification of the hydroxyl group in the sn-2 position of a lysophosphatidylcholine. However, despite the versatility of these conjugates, less is known about the impact of the lipid backbone structure on their 2D phase behavior at the air/water interface and more precisely on their fine structures normal to the interface as well as on their in-plane organization.

Novel liposome-like assemblies composed of phospholipid-porphyrin conjugates with photothermal and photodynamic activities against bacterial biofilms.

Phospholipid-Porphyrin (PL-Por) conjugates are unique building blocks that can self assemble into liposome-like structures with improved photophysical properties compared to their monomeric counterparts. The high packing density of porphyrin moieties enables these assemblies to exhibit high photothermal conversion efficiency as well as photodynamic activity. Thus, PL-Por conjugates assemblies can be used for photodynamic therapy (PDT) and photothermal therapy (PTT) applications against resistant bacteria and biofilms.

Phospholipid-porphyrin conjugates: deciphering the driving forces behind their supramolecular assemblies.

Phospholipid-porphyrin conjugates (PL-Por) are nowadays considered as a unique class of building blocks that can self-assemble into supramolecular structures that possess multifunctional properties and enhanced optoelectronics characteristics compared to their disassembled counterparts. However, despite their versatile properties, little is known about the impact of the packing parameter of PL-Por conjugates on their assembling mechanism and their molecular organization inside these assemblies. To gain a better understanding on their assembling properties, we synthesized two new series of PL-Por conjugates with different alkyl sn2-chain lengths linked an amide bond to either pheophorbide-a (PhLPC) or pyropheophorbide-a (PyrLPC).

Exposure to nitrate from food and drinking-water in New Zealand. Can these be considered separately?

Recent epidemiological studies have reported associations between colorectal cancer incidence and nitrates in drinking-water, but not from the diet. The toxicokinetics of nitrates were reviewed and exposure data from New Zealand were analysed. Dietary (including drinking-water) exposure of New Zealanders to nitrates was found to be very similar to most other countries and within internationally-established acceptable daily intakes.

Influence of the porphyrin structure and linker length on the interfacial behavior of phospholipid-porphyrin conjugates.

Hypothesis: Phospholipid-porphyrin (Pl-Por) conjugates consist of porphyrin derivatives grafted to a lysophosphatidylcholine backbone. Owing to their structural similarities with phospholipids, Pl-Por conjugates can self-assemble into liposome-like assemblies. However, there is a significant lack of information concerning the impact of the porphyrin type and the length of the alkyl chain bearing the porphyrin on the interfacial behavior of the Pl-Por conjugates.

Design and Synthesis of New PEGylated Polydopamine-Based Nanoconstructs Bearing ROS-Responsive Linkers and a Photosensitizer for Bimodal Photothermal and Photodynamic Therapies against Cancer.

Polydopamine (PDA) nanoparticles (NPs) have recently acquired considerable attention for the development of nanoplatforms with multifunctional properties including photothermal (PTT) and photodynamic (PDT) activities. In addition to their high PTT performance, they can be easily conjugated to different types of photosensitizers (PSs) to acquire PDT activity. However, because of PDA free-radical scavenging properties, grafting the PSs directly to PDA surfaces may lead to an inefficient PDT outcome.

Image-guided thermosensitive liposomes for focused ultrasound enhanced co-delivery of carboplatin and SN-38 against triple negative breast cancer in mice.

Triggerable nanocarriers have the potential to significantly improve the therapeutic index of existing anticancer agents. They allow for highly localised delivery and release of therapeutic cargos, reducing off-target toxicity and increasing anti-tumour activity. Liposomes may be engineered to respond to an externally applied stimulus such as focused ultrasound (FUS).

MR-labelled liposomes and focused ultrasound for spatiotemporally controlled drug release in triple negative breast cancers in mice.

Image-guided, triggerable, drug delivery systems allow for precisely placed and highly localised anti-cancer treatment. They contain labels for spatial mapping and tissue uptake tracking, providing key location and timing information for the application of an external stimulus to trigger drug release. High Intensity Focused Ultrasound (HIFU or FUS) is a non-invasive approach for treating small tissue volumes and is particularly effective at inducing drug release from thermosensitive nanocarriers.

Source attributed case-control study of campylobacteriosis in New Zealand.

Background: Following an initial reduction in human campylobacteriosis in New Zealand after the implementation of poultry food chain-focused interventions during 2006-2008, further decline has been relatively small. We report a year-long study of notified campylobacteriosis cases, incorporating a case control study combined with a source attribution study. The purpose was to generate up-to-date evidence on the relative contributions of different sources of campylobacteriosis in New Zealand.

Mercury, methylmercury and long-chain polyunsaturated fatty acids in selected fish species and comparison of approaches to risk-benefit analysis.

Fish (n = 281) of six species, caught in New Zealand waters, were analysed for total mercury (t-Hg), methylmercury (MeHg) and the long-chain polyunsaturated fatty acids, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA). Mean t-Hg and MeHg concentrations for the six species were in the range 0.06-0.

Expert Elicitation for Estimation of the Proportion Foodborne for Selected Microbial Pathogens in New Zealand.

To estimate the proportions of human cases of nine specific microbial diseases in New Zealand that were due to transmission by food and the proportion of the foodborne burden that was due to transmission by some specific foods. Subjective probability distributions were elicited from 10 food safety experts using a modified Delphi approach. In addition to uniform weighting of experts' opinions, two techniques were used to measure individual's expertise; self-assessment and performance-based weighting using Cooke's classical method.

Harmonized methodology to assess chronic dietary exposure to residues from compounds used as pesticide and veterinary drug.

Risk assessments for pesticide and veterinary drug residues in food are performed respectively by the Joint FAO/WHO Expert Meeting on Pesticide Residues (JMPR) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The models used by the two Committees to assess chronic dietary exposure are based on different data and assumptions which may be confusing, particularly for risk managers, when the same compound is used to treat plants and animals. This publication details the results of combined chronic dietary exposure assessments for eight compounds used both as pesticide and veterinary drugs.

Metabolism of cyanogenic glycosides: A review.

Potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide. Information on the metabolism of cyanogenic glycosides is available from in vitro, animal and human studies. In the absence of β-glucosidase enzymes from the source plant material, two processes appear to contribute to the production of cyanide from cyanogenic glycosides; the proportion of the glycoside dose that reaches the large intestine, where most of the bacterial hydrolysis occurs, and the rate of hydrolysis of cyanogenic glycosides to cyanohydrin and cyanide.

Identification of Biological Hazards in Produce Consumed in Industrialized Countries: A Review.

Microbial contamination of fresh produce (fresh fruits and vegetables) poses serious public health concerns worldwide. This study was conducted as a comprehensive analysis of biological hazards in the global fresh produce chain. Data about produce-related outbreaks and illness were collected from the annual reports and databases of foodborne outbreak surveillance systems in different regions and countries from 2010 to 2015.

Cancer Stem Cell and Bulk Cancer Cell Active Copper(II) Complexes with Vanillin Schiff Base Derivatives and Naproxen.

Four copper(II) complexes, 1-4 containing regioisomeric vanillin Schiff base derivatives and the nonsteroidal anti-inflammatory drug (NSAID), naproxen, were synthesised and characterised. All complexes effectively cleave DNA in cell-free systems, with 4 displaying the highest nuclease activity. DNA binding studies suggest that 4 binds to DNA via the grooves prior to inducing oxidative DNA cleavage.

Induction of Necroptosis in Cancer Stem Cells using a Nickel(II)-Dithiocarbamate Phenanthroline Complex.

The cytotoxic properties of a series of nickel(II)-dithiocarbamate phenanthroline complexes is reported. The complexes 1-6 kill bulk cancer cells and cancer stem cells (CSCs) with micromolar potency. Two of the complexes, 2 and 6, kill twice as many breast cancer stem cell (CSC)-enriched HMLER-shEcad cells as compared to breast CSC-depleted HMLER cells.

The breast cancer stem cell potency of copper(ii) complexes bearing nonsteroidal anti-inflammatory drugs and their encapsulation using polymeric nanoparticles.

We report the cancer stem cell (CSC) potency of a novel series of copper(ii)-phenanthroline complexes bearing nonsteriodial anti-inflammatory drugs: naproxen, tolfenamic acid, and indomethacin (2a-3c). Two of the complexes, 2a and 3c, kill breast CSC-enriched HMLER-shEcad cells (grown in both monolayer and three-dimensional cell cultures) to a significantly better extent than salinomycin, a well-established CSC toxin. The most potent complex in the series, 3c induces its cytotoxic effect by generating intracellular reactive oxygen species (ROS) and inhibiting cyclooxgenase-2 (COX-2) activity.

The Potent Inhibitory Effect of a Naproxen-Appended Cobalt(III)-Cyclam Complex on Cancer Stem Cells.

We report the potency against cancer stem cells (CSCs) of a new cobalt(III)-cyclam complex (1) that bears the nonsteroidal anti-inflammatory drug, naproxen. The complex displays selective potency for breast CSC-enriched HMLER-shEcad cells over breast CSC-depleted HMLER cells. Additionally, it inhibited the formation of three-dimensional tumour-like mammospheres, and reduced their viability to a greater extent than clinically used breast cancer drugs (vinorelbine, cisplatin and paclitaxel).

Breast Cancer Stem Cell Potent Copper(II)-Non-Steroidal Anti-Inflammatory Drug Complexes.

The breast cancer stem cell (CSC) potency of a series of copper(II)-phenanthroline complexes containing the nonsteroidal anti-inflammatory drug (NSAID), indomethacin, is reported. The most effective copper(II) complex in this series, 4, selectivity kills breast CSC-enriched HMLER-shEcad cells over breast CSC-depleted HMLER cells. Furthermore, 4 reduces the formation, size, and viability of mammospheres, to a greater extent than salinomycin, a potassium ionophore known to selectively inhibit CSCs.

Understanding staff perspectives of quality in practice in healthcare.

Background: Extensive work has been focussed on developing and analysing different performance and quality measures in health services. However less has been published on how practitioners understand and assess performance and the quality of care in routine practice. This paper explores how health service staff understand and assess their own performance and quality of their day to day work.

Energy drink consumption and impact on caffeine risk.

The impact of caffeine from energy drinks occurs against a background exposure from naturally occurring caffeine (coffee, tea, cocoa and foods containing these ingredients) and caffeinated beverages (kola-type soft drinks). Background caffeine exposure, excluding energy drinks, was assessed for six New Zealand population groups aged 15 years and over (n = 4503) by combining concentration data for 53 caffeine-containing foods with consumption information from the 2008/09 New Zealand Adult Nutrition Survey (ANS). Caffeine exposure for those who consumed energy drinks (n = 138) was similarly assessed, with inclusion of energy drinks.

Cyanogenic glycosides in plant-based foods available in New Zealand.

Cyanogenic glycosides occur in a wide range of plant species. The potential toxicity of cyanogenic glycosides arises from enzymatic degradation to produce hydrogen cyanide, which may result in acute cyanide poisoning and has also been implicated in the aetiology of several chronic diseases. One hundred retail foods were sampled and analysed for the presence of total hydrocyanic acid using an acid hydrolysis-isonicotinic/barbituric acid colourimetric method.

Predictive modelling of interventions to improve iodine intake in New Zealand.

Objective: The potential effects of four interventions to improve iodine intakes of six New Zealand population groups are assessed.

Design: A model was developed to estimate iodine intake when (i) bread is manufactured with or without iodized salt, (ii) recommended foods are consumed to augment iodine intake, (iii) iodine supplementation as recommended for pregnant women is taken and (iv) the level of iodization for use in bread manufacture is doubled from 25-65 mg to 100 mg iodine/kg salt.

Setting: New Zealanders have low and decreasing iodine intakes and low iodine status.