Hierarchical “As-Electrospun” Self-Assembled Fibrous Scaffolds Deconvolute Impacts of Chemically Defined Extracellular Matrix- and Cell Adhesion-Type Interactions on Stem Cell Haptokinesis

Controlled self-assembly of diblock copolymers offers the possibility of fabricating multilength scale, three-dimensional (3D) porous/fibrous structures (or scaffolds) with defined internal nano- or microstructure, with opportunities for application in a variety of fields, ranging from energy storage to bioengineering. Traditional methods by which such 3D constructs are produced are time-consuming and tedious, hindering their broader exploitation within larger-scale industrial processes. We report the development of a one-step process to fabricate “as-electrospun” self-assembled diblock copolymer micro- to nanometer-sized fibers incorporating core–shell or lamellar, closely packed spheres or bicontinuous gyroid nanosized structures. Isotropic and anisotropic (aligned) porous mats presenting spatially controlled chemistries, including bioactive (peptide-based) motifs, were successfully made from these hierarchical fibers. When functionalized with peptide sequences derived from a cell adhesion molecule (<i>E</i>-cadherin) and an extracellular matrix glycoprotein (laminin), these novel materials provided new insight into the impacts of such exquisitely tailored contact-guidance cues on the haptokinesis of human mesenchymal stem cells

Australia and European Union: conflict, competition or engagement in agricultural and agri-food trade

Many scholars have mounted convincing cases that the engagement of Australia and the European Union (EU) has been characterised by skirmishes regarding the Common Agricultural Policy and its distortion of world markets, and lack of Australian access to EU markets. This article illustrates that agricultural and agri-food trade constitutes a relatively small portion of Australia -EU trade flows; that Australia exports more goods to the EU than in the past; and that, in some agri-food sectors, it exports more goods to the EU than the EU does to Australia. Further, it argues that conflict and competition regarding the Common Agricultural Policy need to be understood in the broader context of world trade, particularly with Asia, and in the context of anew and deeper engagement between the two interlocutors

Targeted, Stimuli-Responsive Delivery of Plasmid DNA and miRNAs Using a Facile Self-Assembled Supramolecular Nanoparticle System

Gene therapy is rapidly regaining traction in terms of research activity and investment across the globe, with clear potential to revolutionize medicine and tissue regeneration. Viral vectors remain the most commonly utilized gene delivery vehicles, due to their high efficiency, however, they are acknowledged to have numerous drawbacks, including limited payload capacity, lack of cell-type specificity, and risk of possible mutations in vivo, hence, patient safety. Synthetic nanoparticle gene delivery systems can offer substantial advantages over viral vectors. They can be utilized as off-the-shelf components to package genetic material, display targeting ligands, and release payloads upon environmental triggers and enable the possibility of programmed cell-specific uptake and transfection. In this study, we have synthesized three functional polymeric building blocks that, in a rapid, facile, tailorable, and stage-wise manner, associate through both electrostatic and noncovalent hydrophobic “host–guest” interactions to form monodisperse self-assembled nanoparticles (SaNP). We show that these SaNPs successfully package significant amounts of microRNA through to plasmid DNA, present desired ligands on their outer surface for targeted receptor-mediated cell-specific uptake and affect efficient translation of packaged plasmids. We confirm that these SaNPs outperform commercially available, gold standard transfection agents in terms of in vitro transfection efficiencies and have very low cytotoxicity. With facile self-assembly and tailorable composition, our SaNP gene delivery system has significant potential in targeted gene therapy applications

Comparison of the NT-proBNP immunoassay when compared with a commercially available diagnostic assay (Roche Diagnostics, USA).

<p>r2 = 0.78 and p<0.001.</p

The comparison of the plasma and salivary NT-proBNP concentrations for HF patients (n = 45).

<p>(A), NT-proBNP levels in saliva of HF patients (n = 45) and healthy participants (n = 40). (B), The correlation of NT-proBNP concentrations in plasma and saliva of HF patients measured by our NT-proBNP immunoassay.</p

Growth profile of human embryonic stem cells cultured at physiological and atmospheric oxygen concentrations.

<p>hESCs were harvested as a single cell suspension and then FACS sorted into 6-well plates to ensure a uniform seeding distribution across all wells. The cells were then cultured at physiological, 2%, and atmospheric, 20%, oxygen concentrations. At each time point cells were harvested and counted using flow cytometry techniques. A) The phase contrast images represent the spatial distribution of cells in the well and colony morphology at time equals 0, 47 and 70 hours after the experiment initialisation. The cell seeding methodologies employed allowed for consistent uniform seeding which translated to consistent initial cell numbers. Scale bar represents 500 µm. B) Growth profile of hESCs showing the lag and exponential growth phase on the semi-log plot to determine the specific growth rates. Values are means ± standard deviation, n = 6.</p

Performance characteristics of our NT-proBNP immunoassay.

<p>Performance characteristics of our NT-proBNP immunoassay.</p

Activity of human embryonic stem cells metabolic pathways cultured at physiological and atmospheric oxygen concentrations.

<p>A visual representation of the flux through key metabolic pathways of hESCs cultured at both physiological and atmospheric oxygen concentrations. At both oxygen concentrations glycolysis is disconnected from the TCA cycle. The flux through the glycolysis pathways is greater at physiological oxygen concentrations while the uptake of glutamine and the flux through the respiratory chain is greater at atmospheric oxygen concentrations.</p

Flux of major metabolites consumed and produced by human embryonic stem cells cultured at physiological and atmospheric oxygen concentrations.

<p>Note: All data measured by HPLC analysis, except for ammonia, which was measured using the Bioflex analyser. Values are mean ± standard error, n = 6. Significance between the values measured at 20% and 2% oxygen were determined using a student's t-test where ** indicates a p-value<0.05, deemed statistically significant and *indicates a p-value<0.08, deemed statistically significant.</p><p>Flux of major metabolites consumed and produced by human embryonic stem cells cultured at physiological and atmospheric oxygen concentrations.</p

Characteristics of HF patients and healthy controls.

<p>Results are shown as median (min-max) for the data without normal distribution.</p><p>P_M = p-value for 2-tailed Mann-Whitney <i>U</i> test.</p><p>P_C = p-value for 2-sided Chi-square test.</p>*<p>Significant at 0.05 level.</p><p>n/a = Not applicable.</p