We demonstrate the combination of a rails and anchors microfluidic system with laser forcing to enable the creation of highly controllable 2D droplet arrays. Water droplets residing in an oil phase can be pinned to anchor holes made in the base of a microfluidic channel, enabling the creation of arrays by the appropriate patterning of such holes. The introduction of laser forcing, via laser induced thermocapillary forces to anchored droplets, enables the selective extraction of particular droplets from an array. We also demonstrate that such anchor arrays can be filled with multiple, in our case two, droplets each and that if such droplets have different chemical contents, the application of a laser at their interface triggers their merging and a chemical reaction to take place. Finally by adding guiding rails within the microfluidic structure we can selectively fill large scale arrays with monodisperse droplets with significant control over their contents. In this way we make a droplet array filled with 96 droplets containing different concentrations of fluorescent microparticles.

BackgroundIron oxide nanoparticles (IONPs) have increasing applications in biomedicine, however fears over long term stability of polymer coated particles have arisen. Gold coating IONPs results in particles of increased stability and robustness. The unique properties of both the iron oxide (magnetic) and gold (surface plasmon resonance) result in a multimodal platform for use as MRI contrast agents and as a nano-heater.ResultsHere we synthesize IONPs of core diameter 30 nm and gold coat using the seeding method with a poly(ethylenimine) intermediate layer. The final particles were coated in poly(ethylene glycol) to ensure biocompatibility and increase retention times in vivo. The particle coating was monitored using FTIR, PCS, UV–vis absorption, TEM, and EDX. The particles appeared to have little cytotoxic effect when incubated with A375M cells. The resultant hybrid nanoparticles (HNPs) possessed a maximal absorbance at 600 nm. After laser irradiation in agar phantom a ΔT of 32°C was achieved after only 90 s exposure (50 μgmL-1). The HNPs appeared to decrease T2 values in line with previously clinically used MRI contrast agent Feridex®.ConclusionsThe data highlights the potential of these HNPs as dual function MRI contrast agents and nano-heaters for therapies such as cellular hyperthermia or thermo-responsive drug delivery.

BackgroundEpidemiologic evidence, reinforced by clinical and laboratory studies, shows that the rich Western diet is the major underlying cause of death and disability (e.g, from cardiovascular disease and type 2 diabetes) in Western industrialized societies. The objective of this study is to document the effects that eating a low-fat (≤10% of calories), high-carbohydrate (~80% of calories), moderate-sodium, purely plant-based diet ad libitum for 7 days can have on the biomarkers of cardiovascular disease and type 2 diabetes.MethodsRetrospective analysis of measurements of weight, blood pressure, blood sugar, and blood lipids and estimation of cardiovascular disease risk at baseline and day 7 from 1615 participants in a 10-day residential dietary intervention program from 2002 to 2011. Wilcoxon’s signed-rank test was used for testing the significance of changes from baseline.ResultsThe median (interquartile range, IQR) weight loss was 1.4 (1.8) kg (p < .001). The median (IQR) decrease in total cholesterol was 22 (29) mg/dL (p < .001). Even though most antihypertensive and antihyperglycemic medications were reduced or discontinued at baseline, systolic blood pressure decreased by a median (IQR) of 8 (18) mm Hg (p < .001), diastolic blood pressure by a median (IQR) of 4 (10) mm Hg (p < .001), and blood glucose by a median (IQR) of 3 (11) mg/dL (p < .001). For patients whose risk of a cardiovascular event within 10 years was >7.5% at baseline, the risk dropped to 5.5% (>27%) at day 7 (p < .001).ConclusionsA low-fat, starch-based, vegan diet eaten ad libitum for 7 days results in significant favorable changes in commonly tested biomarkers that are used to predict future risks for cardiovascular disease and metabolic diseases.

We present an all optical technique for the targeted delivery of single 100 nm diameter gold nanoparticles into a specified region of the interior of an individual mammalian cell through a combination of optical tweezing and optical injection. The internalisation of the nanoparticle is verified by confocal laser scanning microscopy and confocal laser scanning reflectance microscopy. This represents the first time that nano sized particles have been tweezed and optically injected into mammalian cells using only light, and provides a novel methodology for internalising nanosphere based biosensors within specific intracellular regions of a mammalian cell.

Irradiation of a mixture of 4-methoxyphenacyl-caged (S)-glutamate and 4,5-dimethoxy-2-nitrobenzyl-caged γ-amino butyric acid (GABA) on neurons, at ~260 nm, evokes selective photorelease of (S)-glutamate (Glu) whereas photolysis at 405 nm causes selective photorelease of GABA.