Precisely synthesized segmented polyurethanes toward block sequence-controlled drug delivery

The construction of polyurethanes (PUs) with sequence-controlled block structures remains a serious challenge. Here, we report the precise synthesis of PUs with desirable molecular weight, narrow molecular weight distribution, and controlled block sequences from commercially available monomers. The synthetic procedure is derived from a liquid-phase synthetic methodology, which involves diisocyanate-based iterative protocols in combination with a convergent strategy. Furthermore, a pair of multifunctional PUs with different sequence orders of cationic and anion segments were prepared. We show that the sequence order of functional segments presents an impact on the self-assembly behavior and results in unexpected surface charges of assembled micelles, thereby affecting the protein absorption, cell internalization, biodistribution and antitumor effect of the nanocarriers in vitro and in vivo. This work provides a versatile platform for the development of precise multiblock PUs with structural complexity and functional diversity, and will greatly facilitate the clinical translation of PUs in biomedicine.

Exotic Vortex Lattices in Binary Repulsive Superfluids

We investigate a mixture of two repulsively interacting superfluids with different constituent particle masses: m_{1}≠m_{2}. Solutions to the Gross-Pitaevskii equation for homogeneous infinite vortex lattices predict the existence of rich vortex lattice configurations, a number of which correspond to Platonic and Archimedean planar tilings. Some notable geometries include the snub-square, honeycomb, kagome, and herringbone lattice configurations. We present a full phase diagram for the case m_{2}/m_{1}=2 and list a number of geometries that are found for higher integer mass ratios.

Facile synthesis of multiarmed and multicomponent star polymers by a new iterative methodology using (formyl-protected 1,3-dioxolane)-end-functionalized polymer anions

In this manuscript, we have developed a new and efficient iterative methodology using formyl-protected 1,3-dioxolane-end-functionalized polymer anions for the facile synthesis of multiarmed and multicomponent miktoarm star polymers.

Development of structural complexity by liquid-crystal self-assembly

Since the discovery of the liquid-crystalline state of matter 125 years ago, this field has developed into a scientific area with many facets. This Review presents recent developments in the molecular design and self-assembly of liquid crystals. The focus is on new exciting soft-matter structures distinct from the usually observed nematic, smectic, and columnar phases. These new structures have enhanced complexity, including multicompartment and cellular structures, periodic and quasiperiodic arrays of spheres, and new emergent properties, such as ferroelctricity and spontaneous achiral symmetry-breaking. Comparisons are made with developments in related fields, such as self-assembled monolayers, multiblock copolymers, and nanoparticle arrays. Measures of structural complexity used herein are the size of the lattice, the number of distinct compartments, the dimensionality, and the logic depth of the resulting supramolecular structures.

Hierarchically ordered microstructures self-assembled from comb-coil block copolymers

Using the real-space implemented self-consistent field theory, we undertook an investigation on the hierarchical self-assembly behaviors of comb-coil block copolymers. The comb-coil block copolymers can self-assemble into hierarchical microstructures with two different length scales. Various structure-within-structure morphologies, such as parallel and perpendicular lamella-within-lamella, cylinder-within-lamella, lamella-within-cylinder, and cylinder-within-cylinder, were observed. In the hierarchical structures, the large-length-scale structures are produced by segregation between the coil blocks and comb blocks, and the small-length-scale structures are formed by microphase separation within the comb blocks. Effects of interaction strength and coil block length on the hierarchical phase behaviors were studied, and the phase diagram was mapped out accordingly. Furthermore, the large-length-scale lamellar period as a function of interaction strength was examined. It was found the lamellar periods are greatly dependent on interaction strengths.