Sequence isomerism in uniform polyphosphoesters programmes self-assembly and folding.

We have adapted solid phase phosphoramidite synthesis commonly used to make DNA, to produce two sequence-isomeric non-biological polymers which display sequence-programmed folding and self-assembly, going beyond structures which would be trivially anticipated. These findings open up possibilities for more sophisticated sequence/structure relationships using the same synthetic platform.

Anisotropic polymer nanoparticles with controlled dimensions from the morphological transformation of isotropic seeds.

Understanding and controlling self-assembly processes at multiple length scales is vital if we are to design and create advanced materials. In particular, our ability to organise matter on the nanoscale has advanced considerably, but still lags far behind our skill in manipulating individual molecules. New tools allowing controlled nanoscale assembly are sorely needed, as well as the physical understanding of how they work.

Cryo-EM of multiple cage architectures reveals a universal mode of clathrin self-assembly.

Clathrin forms diverse lattice and cage structures that change size and shape rapidly in response to the needs of eukaryotic cells during clathrin-mediated endocytosis and intracellular trafficking. We present the cryo-EM structure and molecular model of assembled porcine clathrin, providing insights into interactions that stabilize key elements of the clathrin lattice, namely, between adjacent heavy chains, at the light chain-heavy chain interface and within the trimerization domain. Furthermore, we report cryo-EM maps for five different clathrin cage architectures.

Predicting Monomers for Use in Aqueous Ring-Opening Metathesis Polymerization-Induced Self-Assembly.

Aqueous polymerization-induced self-assembly (PISA) is a well-established methodology enabling synthesis of polymeric nanoparticles of controllable morphology. Notably, PISA ring-opening metathesis polymerization (ROMPISA) is an emerging technology for block copolymer self-assembly, mainly due to its high versatility and robustness. However, a limited number of monomers suitable for core-forming blocks in aqueous ROMPISA have been reported to date.

Poly(sarcosine)-Based Nano-Objects with Multi-Protease Resistance by Aqueous Photoinitiated Polymerization-Induced Self-Assembly (Photo-PISA).

Poly(sarcosine) (PSar) is a non-ionic hydrophilic polypeptoid with numerous biologically relevant properties, making it an appealing candidate for the development of amphiphilic block copolymer nanostructures. In this work, the fabrication of poly(sarcosine)-based diblock copolymer nano-objects with various morphologies via aqueous reversible addition-fragmentation chain-transfer (RAFT)-mediated photoinitiated polymerization-induced self-assembly (photo-PISA) is reported. Poly(sarcosine) was first synthesized via ring-opening polymerization (ROP) of sarcosine N-carboxyanhydride, using high-vacuum techniques.

Predicting Monomers for Use in Polymerization-Induced Self-Assembly.

We report an in silico method to predict monomers suitable for use in polymerization-induced self-assembly (PISA). By calculating the dependence of LogP  /surface area (SA) on the length of the growing polymer chain, the change in hydrophobicity during polymerization was determined. This allowed for evaluation of the capability of a monomer to polymerize to form self-assembled structures during chain extension.

Poly(Pentafluorophenyl Methacrylate)-Based Nano-Objects Developed by Photo-PISA as Scaffolds for Post-Polymerization Functionalization.

The preparation of a functional fluorine-containing block copolymer using reversible addition-fragmentation chain-transfer dispersion polymerization in DMSO as a "platform/scaffold" is explored. The nanostructures, comprised of poly(ethyleneglycol)-b-poly(pentafluorophenyl methacrylate) or PEG-b-P(PFMA), are formulated via photo-initiated polymerization-induced self-assembly (PISA) followed by post-polymerization modification using different primary amines. A combination of light scattering and microscopy techniques are used to characterize the resulting morphologies.

Controlling the Size of Two-Dimensional Polymer Platelets for Water-in-Water Emulsifiers.

A wide range of biorelevant applications, particularly in pharmaceutical formulations and the food and cosmetic industries, require the stabilization of two water-soluble blended components which would otherwise form incompatible biphasic mixtures. Such water-in-water emulsions can be achieved using Pickering stabilization, where two-dimensional (2D) nanomaterials are particularly effective due to their high surface area. However, control over the shape and size of the 2D nanomaterials is challenging, where it has not yet been possible to examine chemically identical nanostructures with the same thickness but different surface areas to probe the size-effect on emulsion stabilization ability.