Front Cover: This special issue is dedicated to commemorate Wolfgang P. Meier, who had significant contributions in the fields of amphiphilic copolymer syntheses and their hierarchical self-assembly, block copolymer vesicles (so-called polymersomes), and hybrid membranes. The self-assembly of amphiphilic molecules is generating nano- or microassemblies (membranes, micelles, vesicles or nanoparticles) that can be combined with biomolecules for various applications, ranging from medicine up to food science and technology. In the guest editorial article number 2300401 by Nico Bruns, Corinne Nardin, and Cornelia G. Palivan, an overview of all the articles that contribute to this combined special issue is presented.

Inside Front Cover: Poly(vinyl alcohol)-b-poly(styrene) copolymer (PVA-b-PS) self-assembles in solution, and after coating and drying, it forms a semipermeable self-assembled membrane, as demonstrated by Wilfredo Yave and co-workers in article number 2200875. PVA is the permeable matrix and PS acts as an impermeable nanodomain. The design of this tailor-made block copolymer eliminates the use of chemical cross-linkers and acid catalysts to manufacture PVA membranes.

Back Cover: Article 2200864 by Esther Amstad and co-worker demonstrates that the stiffness of swollen microgel-reinforced hydrogels (MRHs) depends on the connectivity between the fragmented microgels, which is closely related to their initial volume fraction. By contrast, the fracture toughness linearly scales with the effective volume fraction of microgels in the MRHs regardless of their connectivity. These insights provide universal design guidelines for the targeted design tough granular hydrogels that stiffen upon swelling.

Encapsulation of multiple different cargo molecules into nanocarriers is crucial for enhancing medical therapy, where several compounds have to work together. Coencapsulation of cargo molecules with different physicochemical properties is challenging in terms of control, efficacy, and orthogonality. This review focuses on the coencapsulation of multiple cargo molecules into biocompatible and biodegradable nanocarriers prepared by orthogonal strategies.

Basic knowledge (chemistry, material science, colloid science, and biology) is required for preparing high performance fluorine magnetic resonance imaging (¹⁹F MRI) probes and their potential application domains.

Cyclic ketene acetals (CKAs) polymerize into polyesters through radical ring-opening polymerization. A large number of CKAs are now available through a multitude of synthetic routes. The polyesters then have distinct structural irregularities like ring-retaining and branching units, which affect the macroscopic properties of the materials. This review addresses the points mentioned and looks at possible applications as amphiphilic block-copolymers.

The oxidation of dopamine allows to produce polydopamine (PDA) coatings which adhere to almost all kinds of interfaces, even water/air interfaces. This review article describes the synthesis methods of PDA, using either solution chemistry, oxidation from the solid state, spray deposition, and electrodeposition. It also aims to compare the properties of the obtained coatings. Many research efforts are still required to better understand the structure and properties of PDA coatings (and nanomaterials).

Fragrances find ubiquitous applications in everyday life, for example, in perfumes, cosmetics, textile finishes, and laundry formulations. However, they are based on small organic molecules that easily evaporate, which rapidly depletes the pleasant smell. To make them longer-lasting, fragrances are encapsulated in a variety of host structures ranging from cyclodextrins to polymer microcapsules, inorganic microcapsules, block copolymer micelles, and polymersomes.

Controlling the polymer building blocks, membranes with outstanding separation performance are obtained. These membranes are based on poly(vinyl alcohol)-b-poly(styrene) (PVA-b-PS). The PVA block forms the semipermeable matrix, while the PS block acts as impermeable nanodomains. This feature means that chemical cross-linkers and acid catalysts are no longer necessary to produce PVA membranes.

The stiffness and toughness of conventional hydrogels decrease with increasing degree of swelling, limiting their use for load-bearing applications. This shortcoming can be addressed by reinforcing them with microgels that introduce the double network toughening effect into hydrogels. In this work, the microstructure of microgel-reinforced hydrogels and in particular their degree of swelling is correlated to their mechanical properties.

Amino-l-tyrosine is electropolymerized for the first time forming ultrathin films. The material does not show relevant charge transfer resistance or fluorescence quenching abilities, which enables its application for sensing technologies. The growth rate differs from the known polydopamine and polynorepinphrine showing also swelling abilities and easy degradation under mild conditions.

Atom transfer radical polymerization (ATRP) of oligo(ethylene oxide) monomethyl ether methacrylate (OEOMA₅₀₀) in water is enabled using CuBr₂ with excess of tris(2 pyridylmethyl)amine (TPMA) as a ligand under green-light irradiation without any additional reagents or the need for prior deoxygenation. TPMA impurities, especially imines and nitrone dipyridines, are identified as the major triggers for the observed ATRP under green light.

A novel method is established to reversibly capture and release molecules by supramolecular interactions of poly(acrylamide) hydrogel dots grafted by β-cyclodextrine in the microfluidic device. Ranging from small molecule (dye labelled adamantane) to macromolecule (dye labelledadamantane-poly(2-methyl-2-oxazoline) ), the reproducible capture and release demonstrates the stability of the microfluidic system and provides opportunities for future applications such as diagnostics.

Stimuli-responsive and crosslinked polymeric vesicles bearing Fc moieties enables the docking of β-CD-based cargo via host–guest interaction, and the undocking of molecular cargos can be modulated via two distinct enzymatic mechanisms, that is, the GOx-induced glucose oxidation (reversible) and AmyL-induced degradation of β-CD (irreversible) in the swollen membrane, accompanied with the FRET effect being off and on.

Using the M13 phage display, a series of 7- and 12-mer peptides which interact with new sulfobetaine hydrogels can be identified. This is the first report of peptides binding to zwitterionic sulfobetaine hydrogels and the study therefore opens up the pathway toward new phage or peptide/hydrogel hybrids with high application potential.

The authors examine the adsorption of a series of sterically-stabilized diblock copolymer nanoparticles onto a model stainless steel substrate using a quartz crystal microbalance. The adsorbed amount depends on both the mean diameter and the surface functionality of the nanoparticles. Introducing histidine groups via periodate oxidation and reductive amination leads to twice the adsorbed amount compared to cis-diol groups.

A polymersome nanoreactor is developed, which is modified with a copper catalyst in its membrane. The reactor is efficiently taken up by cells and shows intracellular activity by catalyzing an azide-alkyne cycloaddition reaction in the protective membrane environment. The biodegradable nature of this artificial organelle opens up perspectives for its usage in therapeutic applications.

Propargyl acrylate and propargyl methacrylate provide the means to achieve chemical tailoring of the polymer moiety of protein-polymer conjugates under facile and mild conditions. Multifunctional protein-polymer conjugates are synthesized via oxygen-tolerant, aqueous controlled radical polymerization, and copper-catalyzed [3+2] Huisgen cycloaddition or thiol-yne click chemistry in a sequential or a simultaneous manner.

A mean-field theory of colloid binding and transport in planar polymer brushes is presented. Position-dependent free energy of colloid insertion is derived as a function of solvent strength, colloid size, and colloid-polymer affinity. Brush permeability is quantitated and it is shown that brushes can serve as tuneable gates for selecting colloids by their size and affinity for the polymer.