Nanocomposites of polymer and inorganic nanoparticles for optical and magnetic applications

This article provides an up-to-date review on nanocomposites composed of inorganic nanoparticles and the polymer matrix for optical and magnetic applications. Optical or magnetic characteristics can change upon the decrease of particle sizes to very small dimensions, which are, in general, of major interest in the area of nanocomposite materials. The use of inorganic nanoparticles into the polymer matrix can provide high-performance novel materials that find applications in many industrial fields. With this respect, frequently considered features are optical properties such as light absorption (UV and color), and the extent of light scattering or, in the case of metal particles, photoluminescence, dichroism, and so on, and magnetic properties such as superparamagnetism, electromagnetic wave absorption, and electromagnetic interference shielding. A general introduction, definition, and historical development of polymer–inorganic nanocomposites as well as a comprehensive review of synthetic techniques for polymer–inorganic nanocomposites will be given. Future possibilities for the development of nanocomposites for optical and magnetic applications are also introduced. It is expected that the use of new functional inorganic nano-fillers will lead to new polymer–inorganic nanocomposites with unique combinations of material properties. By careful selection of synthetic techniques and understanding/exploiting the unique physics of the polymeric nanocomposites in such materials, novel functional polymer–inorganic nanocomposites can be designed and fabricated for new interesting applications such as optoelectronic and magneto-optic applications

Polymeric electrospun scaffolds: neuregulin encapsulation and biocompatibility studies in a model of myocardial ischemia

Cardiovascular disease represents one of the major health challenges in modern times and is the number one cause of death globally. Thus, numerous studies are under way to identify effective cell‐ and/or growth factor‐based therapies for repairing damaged cardiac tissue. In this regard, improving the engraftment or survival of regenerative cells and prolonging growth factor exposure have become fundamental goals in advancing these therapeutic approaches. Biomaterials have emerged as innovative scaffolds for the delivery of both cells and proteins in tissue engineering applications. In the present study, electrospinning was used to generate smooth homogenous polymeric fibers, which consisted of a PLGA/NCO‐sP(EO‐stat‐PO) polymer blend encapsulating the cardioactive growth factor, Neuregulin‐1 (Nrg). We evaluated the biocompatibility and degradation of this Nrg‐containing biomaterial in a rat model of myocardial ischemia. Histological analysis revealed the presence of an initial acute inflammatory response after implantation, which was followed by a chronic inflammatory phase, characterized by the presence of giant cells. Notably, the scaffold remained in the heart after 3 months. Furthermore, an increase in the M2:M1 macrophage ratio following implantation suggested the induction of constructive tissue remodeling. Taken together, the combination of Nrg‐encapsulating scaffolds with cells capable of inducing cardiac regeneration could represent an ambitious and promising therapeutic strategy for repairing diseased or damaged myocardial tissue

Particle tracking for polydisperse sedimenting droplets in phase separation

When a binary fluid demixes under a slow temperature ramp, nucleation, coarsening and sedimentation of droplets lead to an oscillatory evolution of the phase separating system. The advection of the sedimenting droplets is found to be chaotic. The flow is driven by density differences between the two phases. Here, we show how image processing can be combined with particle tracking to resolve droplet size and velocity simultaneously. Droplets are used as tracer particles, and the sedimentation velocity is determined. Taking these effects into account, droplets with radii in the range of 4 -- 40 micrometers are detected and tracked. Based on this data we resolve the oscillations in the droplet size distribution which are coupled to the convective flow.Comment: 13 pages; 16 figures including 3 photographs and 3 false-color plot

Polymeric electrospun scaffolds: neuregulin encapsulation and biocompatibility studies in a model of myocardial ischemia

Cardiovascular disease represents one of the major health challenges in modern times and is the number one cause of death globally. Thus, numerous studies are under way to identify effective cell‐ and/or growth factor‐based therapies for repairing damaged cardiac tissue. In this regard, improving the engraftment or survival of regenerative cells and prolonging growth factor exposure have become fundamental goals in advancing these therapeutic approaches. Biomaterials have emerged as innovative scaffolds for the delivery of both cells and proteins in tissue engineering applications. In the present study, electrospinning was used to generate smooth homogenous polymeric fibers, which consisted of a PLGA/NCO‐sP(EO‐stat‐PO) polymer blend encapsulating the cardioactive growth factor, Neuregulin‐1 (Nrg). We evaluated the biocompatibility and degradation of this Nrg‐containing biomaterial in a rat model of myocardial ischemia. Histological analysis revealed the presence of an initial acute inflammatory response after implantation, which was followed by a chronic inflammatory phase, characterized by the presence of giant cells. Notably, the scaffold remained in the heart after 3 months. Furthermore, an increase in the M2:M1 macrophage ratio following implantation suggested the induction of constructive tissue remodeling. Taken together, the combination of Nrg‐encapsulating scaffolds with cells capable of inducing cardiac regeneration could represent an ambitious and promising therapeutic strategy for repairing diseased or damaged myocardial tissue