Ouzo Effect Examined at the Nanoscale via Direct Observation of Droplet Nucleation and Morphology.

Herein, we present the direct observation via liquid-phase transmission electron microscopy (LPTEM) of the nucleation and growth pathways of structures formed by the so-called "ouzo effect", which is a classic example of surfactant-free, spontaneous emulsification. Such liquid-liquid phase separation occurs in ternary systems with an appropriate cosolvent such that the addition of the third component extracts the cosolvent and makes the other component insoluble. Such droplets are homogeneously sized, stable, and require minimal energy to disperse compared to conventional emulsification methods.

Intravascularly infused extracellular matrix as a biomaterial for targeting and treating inflamed tissues.

Decellularized extracellular matrix in the form of patches and locally injected hydrogels has long been used as therapies in animal models of disease. Here we report the safety and feasibility of an intravascularly infused extracellular matrix as a biomaterial for the repair of tissue in animal models of acute myocardial infarction, traumatic brain injury and pulmonary arterial hypertension. The biomaterial consists of decellularized, enzymatically digested and fractionated ventricular myocardium, localizes to injured tissues by binding to leaky microvasculature, and is largely degraded in about 3 d.

Direct Observation of Emulsion Morphology, Dynamics, and Demulsification.

Herein, we present the direct observation and quantification of a water-in-oil (w/o) emulsion, its destabilization, and the effect of additives on such processes at the nanoscale. This is achieved liquid phase transmission electron microscopy (LPTEM), wherein a small volume of emulsion is encapsulated against vacuum in its liquid state to allow observation of its initial morphology and its evolution over time at excellent spatial and temporal resolution. Emulsions of this class are useful for delivering payloads of materials insoluble in their delivery medium and are currently widely used across food science, pharmaceuticals, and environmental applications.

Complex Nanoparticle Diffusional Motion in Liquid-Cell Transmission Electron Microscopy.

Liquid-cell transmission electron microscopy (LCTEM) is a powerful in situ videography technique that has the potential to allow us to observe solution-phase dynamic processes at the nanoscale, including imaging the diffusion and interaction of nanoparticles. Artefactual effects imposed by the irradiated and confined liquid-cell vessel alter the system from normal "bulk-like" behavior in multiple ways. These artefactual LCTEM effects will leave their fingerprints in the motion behavior of the diffusing objects, which can be revealed through careful analysis of the object-motion trajectories.

Proapoptotic Peptide Brush Polymer Nanoparticles via Photoinitiated Polymerization-Induced Self-Assembly.

Herein, we report the photoinitiated polymerization-induced self-assembly (photo-PISA) of spherical micelles consisting of proapoptotic peptide-polymer amphiphiles. The one-pot synthetic approach yielded micellar nanoparticles at high concentrations and at scale (150 mg mL ) with tunable peptide loadings up to 48 wt. %.

Biomolecular Densely Grafted Brush Polymers: Oligonucleotides, Oligosaccharides and Oligopeptides.

In this Minireview, we describe synthetic polymers densely functionalized with sequence-defined biomolecular sidechains. We focus on synthetic brush polymers of oligonucleotides, oligosaccharides, and oligopeptides, prepared via graft-through polymerization from biomolecule functionalized monomers. The resulting structures are brush polymers wherein a biomolecular graft is positioned at each monomer backbone unit.

Enhanced elasticity in poly(acrylic acid) gels via synthesis in the presence of high concentrations of select salts.

Poly(acrylic acid) (PAA) gels synthesized via free-radical polymerization of acrylic acid, N,N'-methylenebisacrylamide and high molarities of salts in water exhibit properties markedly different from PAA gels synthesized without salt, even when the latter are incubated in high-molarity salt solutions after gelation. Particularly noteworthy is unusual mechanical behaviour that includes substantially increased elongation, increased modulus, and rapid recovery after strain. The greatest enhancement in viscoelastic behaviour is evident in 2 M LiCl and ZnCl samples, with LiCl samples having a modulus of 39 kPa and reaching an extension ratio of 10 and a fracture stress of 135 kPa, and ZnCl samples having a modulus of 43 kPa and reaching an extension ratio of 8.

Design of a Fibrin Microthread-Based Composite Layer for Use in a Cardiac Patch.

The ability to modulate the mechanical properties, and cell alignment within a cardiac patch without hindering cell functionality may have significant impact on developing therapies for treating myocardial infarctions. We developed fibrin-based composite layers comprising aligned microthreads distributed uniformly throughout a hydrogel. Increasing the microthread volume fraction (∼5%, 11% and 22%) significantly increased the moduli of the scaffolds (20.