Multiple H-Bonds Directed Self-Assembly of an Amphiphilic and Plate-Like Codendrimer with Janus Faces at Water−Air Interface

Synthesis of amphiphilic, Janus diblock hyperbranched copolyamides and their self-assembly in water

An amphiphilic, Janus diblock hyperbranched copolyamide was synthesized by the condensation reaction, and the morphologies of aggregates in water were changed from spherical to dendritic-like structures via cylindrical-like structures in response to increasing temperature.

Small is beautiful: Surprising nanoparticles

In the preparation of nanoparticles for drug delivery, it is well known that their size as well as their surface decorations can play a major role in interaction with living media. It is less known that their shape and internal structure can interplay with cellular and in vivo fate. The scientific literature is full of a large variety of surprising terms referring to their shape and structure. The aim of this review is to present some examples of the most often encountered surprising nanoparticles prepared and usable in the pharmaceutical technology domain. They are presented in two main groups related to their physical aspects: 1) smooth surface particles, such as Janus particles, "snowmen", "dumbbells", "rattles", and "onions" and 2) branched particles, such as "flowers", "stars" and "urchins". The mode of preparation and potential applications are briefly presented. The topic has a serious, wider importance, namely in opportunity these structures have to allow exploration of the role of shape and structure on the utility (and perhaps toxicity) of these nanostructures.

Janus long-chain hyperbranched copolymers of PSt and POEGMA from a self-assembly mediated click reaction

A Janus hyperbranched POEGMA/PSt copolymer with long sub-chains was prepared through a self-assembly mediated click reaction in selective solvents.

Dendrimersomes with photodegradable membranes for triggered release of hydrophilic and hydrophobic cargo

Amphiphilic Janus dendrimers with fully photodegradable hydrophobic blocks were synthesized and assembled into dendrimersomes in water. Irradiation with UV light triggered the release of hydrophobic and hydrophilic cargo.

Functional supramolecular assemblies derived from dendritic building blocks

Control of the structure and function of self-assembled materials has been a significant issue in many areas of nanoscience. Among many different types of building blocks, dendritic ones have shown interesting self-assembly behaviour and functional performances due to their unique shape and multiple functionalities. Dendritic building blocks exhibit unique self-assembly behaviour in diverse environments such as aqueous and organic solutions, solid-liquid interfaces, and thermotropic solid conditions. Tuning the balance between hydrophilic and hydrophobic parts, as well as the external conditions for self-assembly, provides unique opportunities for control of supramolecular architectures. Furthermore, the introduction of suitable functional moieties into dendrons enables us to control self-assembly characteristics, allowing nanostructures to exhibit smart performances for electronic or biological applications. The self-assembly characteristics of amphiphilic dendrons under various conditions were investigated to elucidate how dendrons can assemble into nanoscopic structures and how these nanoassemblies exhibit unique properties. Well-defined nanostructures derived from self-assembly of dendrons provide an efficient approach for exhibition of unique functions at the nanoscale. This feature article describes the unique self-assembly characteristics of various types of dendritic building blocks and their potential applications as advanced materials.

Breaking symmetry toward nonspherical Janus particles based on polyhedral oligomeric silsesquioxanes: molecular design, "click" synthesis, and hierarchical structure

The design, synthesis, and self-assembly of a series of precisely defined, nonspherical, polyhedral oligomeric silsesquioxane (POSS)-based molecular Janus particles are reported. The synthesis aims to fulfill the "click" philosophy by using thiol-ene chemistry to efficiently install versatile functionalities on one of the POSS cages. In such a way, both the geometrical and chemical symmetries were broken to create the Janus feature. These particles self-organize into hierarchically ordered supramolecular structures in the bulk. For example, the Janus particle with isobutyl groups on one POSS and carboxylic groups on the other self-assembles into a bilayered structure with head-to-head, tail-to-tail arrangements of each particle, which further organize into a three-dimensional orthorhombic lattice. While the ordered structure in the layers was lost upon heating via a first-order transition, the bilayered structure persisted throughout. This study provides a model system of well-defined molecular Janus particles for the general understanding of their self-assembly and hierarchical structure formation in the condensed state.

Ribbonlike assembly of molecules composed of fulleropyrrolidine and PUA dendron

The hybrid molecules composed of fulleropyrrolidine and poly(urethane amide) dendron of the third generation have been synthesized, and their self-assembling in THF/water mixtures has been studied. By TEM, AFM, and SAXS methods it was established that molecules form ribbonlike aggregates with the ordered layers of fullerene derivatives situated inside of the ribbons. Microscale length and high ratio width/thickness were detected for the ribbons. The ability of amides and urethanes to initiate a coupling of dendron-fragments by means of hydrogen bonding has been considered as mainly responsible for anisotropic interaction of hybrid molecules and for the ribbonlike aggregates formation in THF/water mixtures.