Paclitaxel-induced formation of 3D nanocrystal superlattices within injectable protein-based hybrid nanoparticles.

Self-assembly of monodisperse superparamagnetic iron oxide nanocrystals into a close-packed, three-dimensional (3D) superlattice is designed within cross-linked protein-based nanoparticles composed of human serum albumin and polyethylene glycol. The prepared nanoparticles are very stable in serum and exhibit a high T2 relaxivity as well as anti-cancer activity, indicating the practical benefits of ordering nanocrystals.

Tannin-Titanium Oxide Multilayer as a Photochemically Suppressed Ultraviolet Filter.

UV filters can initiate redox reactions of oxygen and water when exposed to sunlight, generating reactive oxygen species (ROS) that deteriorate the products containing them and cause biological damages. This photochemical reactivity originates from the high chemical potential of UV filters, which also determines the optical properties desirable for sunscreen applications. We hypothesize that this dilemma can be alleviated if the photochemical pathway of UV filters is altered to coupling with redox active molecules.

Multilayered Plasmonic Heterostructure of Gold and Titania Nanoparticles for Solar Fuel Production.

Solar fuel production via photoelectrochemical (PEC) water splitting has attracted great attention as an approach to storing solar energy. However, a wide range of light-harvesting materials is unstable when exposed to light and oxidative conditions. Here we report a robust, multilayered plasmonic heterostructure for water oxidation using gold nanoparticles (AuNPs) as light-harvesting materials via localized surface plasmon resonance (LSPR).

Morphological Evolution of Gold Nanoparticles into Nanodendrites Using Catechol-Grafted Polymer Templates.

Morphology, dimension, size, and surface chemistry of gold nanoparticles are critically important in determining their optical, catalytic, and photothermal properties. Although many techniques have been developed to synthesize various gold nanostructures, complicated and multistep procedures are required to generate three-dimensional, dendritic gold nanostructures. Here, we present a simple method to synthesize highly branched gold nanodendrites through the well-controlled reduction of gold ions complexed with a catechol-grafted polymer.

Layer-by-layer siRNA/poly(L-lysine) Multilayers on Polydopamine-coated Surface for Efficient Cell Adhesion and Gene Silencing.

For tissue engineering applications, small interfering RNA (siRNA) is an attractive agent for controlling cellular functions and differentiation. Although polyionic condensation of nucleic acids with polycations has been widely used for gene delivery, siRNA is not strongly associated with cationic carriers due to its low charge density and rigid molecular structures. The use of an excess amount of cationic carriers is often used for siRNA condensation, though they can induce severe cytotoxicity.

Bioinspired Synthesis of Mesoporous Gold-silica Hybrid Microspheres as Recyclable Colloidal SERS Substrates.

Noble metal nanostructures have been intensively investigated as active substrates for surface-enhanced Raman spectroscopy (SERS) from visible to near-IR wavelengths. However, metal nanoparticle-based SERS analysis in solutions is very challenging due to uncontrollable and irreproducible colloid aggregation. Here we report the templated synthesis of porous gold-silica hybrid microspheres and their application as reusable colloidal SERS substrates.

Bioinspired Design of an Immobilization Interface for Highly Stable, Recyclable Nanosized Catalysts.

Immobilization of nanometer-sized metal catalysts into porous substrates can stabilize the catalysts and allow their recycled uses, while immobilization often sacrifices the active surface of catalysts and degenerates the local microenvironments, resulting in the reduction of the catalytic activity. To maintain a high activity of immobilized nanocatalysts, it is critically important to design an interface that minimizes the contact area and favors reaction chemistry. Here we report on the application of mussel-inspired adhesion chemistry to the formation of catalytic metal nanocrystal-polydopamine hybrid materials that exhibit a high catalytic efficiency during recycled uses.

Bioinspired templating synthesis of metal-polymer hybrid nanostructures within 3D electrospun nanofibers.

Novel metal nanostructures immobilized within three-dimensional (3D) porous polymeric scaffolds have been utilized for catalysts and biosensors. However, efficient, robust immobilization of the nanostructures both outside and inside of the 3D scaffolds is a challenging task. To address the challenge, we synthesized a redox-active polymer, catechol-grafted poly(vinyl alcohol), PVA-g-ct.