Reproducibility and comparability of photocatalytic experiments are still challenging, owing to the large number of experimental parameters and their comprehensive documentation. To overcome this limitation, a modular, adaptable, and extensible photoreactor platform is reported, which enables experiments under well‐characterized, reproducible conditions. Comparability is ensured by comprehensive photonic characterization with chemical actinometry, radiometry and open documentation of the incident photon fluxes in the reaction vessels for different setups as well as the homogeneity of irradiation in multi‐reactor setups. Comprehensive documentation minimizes the need for repeated photonic characterization when modifying the setups. Experimental reproducibility within and across experiments was evaluated with studies of photocatalytic systems for hydrogen evolution, emphasizing the validity of the concept.

Three triggers result in two measurable outputs from polymeric sensors: multiresponsive polyampholytic graft copolymers respond to pH‐value and temperature, as well as the type and concentration of metal cations and therefore, allow the transformation of external triggers into simply measurable outputs (cloud point temperature (TCP) and surface plasmon resonance (SPR) of encapsulated silver nanoparticles). The synthesis relies on poly(dehydroalanine) (PDha) as the reactive backbone and gives straightforward access to materials with tunable composition and output. In particular, a rather high sensitivity toward the presence of Cu2+, Co2+, and Pb2+ metal cations is found.

We herein report the fabrication of core-crosslinked, fluorescent, and surface-functionalized worm-like block copolymer micelles as drug delivery vehicles. The polyether-based diblock terpolymer [allyl-poly(ethylene oxide)-block-poly(2-ethylhexyl glycidyl ether-co-furfuryl glycidyl ether)] was synthesized via anionic ring opening polymerization, and self-assembly in water as a selective solvent led to the formation of long filomicelles. Subsequent cross-linking was realized using hydrophobic bismaleimides as well as a designed fluorescent cross-linker for thermally induced Diels−Alder reactions with the furfuryl units incorporated in the hydrophobic block of the diblock terpolymer. As a fluorescent cross-linker, we synthesized and incorporated a cyanine 5-based bismaleimide in the cross-linking process, which can be used for fluorescence tracking of the particles. Furthermore, we covalently attached glucose to the allyl end groups present on the surface of the micelles to investigate active glucose-mediated transport into suitable cell lines. First studies in 2D as well as 3D cell culture models suggest a glucose-dependent uptake of the particles into cells despite their unusually large size compared to other nanoparticle systems used in drug delivery.

Melanins are a class of biopolymers that are widespread in nature, with diverse origins, compositions, and functions, and their chemical and optoelectronic properties render them potentially useful for application in materials science for various biotechnological applications. For patients with alkaptonuria, the accumulation of homogentisic acid (HGA) in their bodies is associated with the concomitant deposition of pyomelanin, which is a pigment that contains significant amounts of polymerized HGA (polyHGA) in the bodily tissues of the patients. The polymerization of HGA under various different conditions in vitro is investigated using a selection of different analytical chemistry techniques to understand if there may be a correlation between the conditions and pigment deposition in vivo, and their potential for application as green/sustainable and components of electronic devices.

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Herein, we describe the preparation as well as experimental and theoretical investigations of block copolymer micelles based on amphiphilic, pH-responsive block copolymers featuring bipyridine ligands in the side chain. Several well-defined polystyrene-block-poly(acrylic acid) (PS-b-PAA) and polystyreneblock-poly((acrylic acid)-co-(2-(4-(4′-methyl-2,2′-bipyridyl))ethylacrylate)) (PS-b-P(AA-co-bpyEA)) block copolymers were synthesized via nitroxide-mediated polymerization. Morphological investigations of different PS-b-PAA and PS-b-P(AA-co-bpyEA) block copolymer micelles in water using dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM) revealed spherical micelles with pH-dependent corona size. The coronae of the micelles can be regarded as polyelectrolytes in the case of PS-b-PAA and polyampholytes in the case of PS-b-P(AA-co-bpyEA). To describe the conformational behavior of the micellar coronae, we performed combined molecular dynamics (MD) and Monte Carlo (MC) simulations of pH-sensitive brushes with comparable grafting density and matching composition. We have studied the brush thickness, degree of dissociation of monomer units, and distributions of functional groups at different solution pH values. Particular emphasis has been put on distribution and average distance between bipyridyl units as model functional groups and the theoretically obtained macrocharacteristics are in good agreement with the experimental results. Afterward, a platinum(II) complex was immobilized covalently at the bipyridine anchoring sites of a selected polystyrene-block-poly((tert-butyl acrylate)-co-(2-(4-(4′-methyl-2,2′bipyridyl))ethyl acrylate)) (PS-b-P( t BuA-co-bpyEA)) block terpolymer. After deprotecting the t BuA groups to AA, the obtained amphiphilic diblock terpolymer formed core−corona micelles with pH-dependent corona thickness in water according to DLS and TEM investigations.

Inside cover: In article number 2000671 by Felix H. Schacher and co‐workers, triple stimuli‐responsive polymeric materials are obtained via a straightforward synthetic route. Exhibiting a thermosensitive side chain and a polyampholytic backbone, these materials react to changes in environmental pH, temperature, as well as the presence and the amount of metal ions. As this results in simple outputs like turbidity or a shift of absorption, a high potential is foreseen in sensing applications.

The synthesis of 9-methylanthracenyl glycidyl ether (AnthGE) as a crosslinkable monomer that can be applied in anionic ring opening polymerization is reported. Diblock terpolymers of the composition methoxy-poly(ethylene oxide)-block-poly(2-ethylhexyl glycidyl ether-co-9-methylanthracenyl glycidyl ether) (mPEO-b-P(EHGE-co-AnthGE) with 10 to 24 wt% of AnthGE are synthesized and characterized. Their micellization behavior, as well as their light-induced core-crosslinking via irradiation with UV light (𝝀 = 365 nm) is studied. The results are compared with studies on the dimerization, and the dimer cleavage via irradiation with UV-C light (𝝀 = 254 nm), of the same diblock terpolymer in organic solution, and the small-molecule model compound 9-methoxymethylanthracene. Differences in 1 H NMR spectra of the crosslinked or dimerized compounds and reaction kinetics of the dimerization reactions under different conditions suggest possible side reactions for the case of the core-crosslinking of micelles in aqueous solution. These side reactions limit the reversibility of the anthracene dimerization reaction in aqueous solutions, even if the anthracene molecule is encapsulated within the hydrophobic core of a polymeric micelle.