Exploiting Boron Coordination: B←N Bond Supports a [2+2] Photodimerization in the Solid State and Generation of a Diboron Bis‐Tweezer for Benzene/Thiophene Separation

B←N coordination supports a [2+2] photodimerization in the solid state. The bond is defined by an orthogonal interaction between stilbazole and a phenylboronic ester to enable a stereocontrolled and rapid photoreaction. The cyclobutane photoproduct affords a novel diboron bis‐tweezer adduct that is used to separate a mixture of benzene and thiophene upon crystallization.     

A Borocarbonitride Ceramic Aerogel for Photoredox Catalysis

Borocarbonitride (BCN) is a new type of photocatalyst, but bulk BCN shows a large band gap, and low surface area, and moderate activity for photocatalysis. Here, a three‐dimensional (3D) porous ceramic BCN aerogel was developed as an effective photocatalyst for relevant reactions. The unique structures endow the aerogel with an adjustable band gap and a high surface area, excellent stability, and improved crystallinity, which accelerates the separation and transfer of electron‐hole pairs and promotes catalytic kinetics, thus enhancing the performance of photocatalytic reactions for hydrogen generation and carbon dioxide reduction. This work supplies a low‐cost, convenient and green synthesis method for building ceramic aerogels, and it provides a simple colloid chemistry strategy combined with boron‐containing compounds to facilitate further innovative breakthroughs in the novel ceramic aerogel materials design and development in the field of catalysis.     

Revision komplexer supramolekularer Polymerisation unter kinetischer und thermodynamischer Kontrolle

Pathway‐Complexity, hierarchische Organisation, Außer‐Equilibrium‐ und metastabile oder kinetisch gefangene Spezies sind Begriffe die in jüngsten, hochqualitativen Publikationen im Feld der supramolekularen Polymere häufig verwendet werden. Oftmals sind die Terminologien, die die verschiedenen Selbstassemblierungspfade, die beteiligten Spezies und deren Beziehung sowie relativen Stabilitäten zueinander beschreiben, nicht trivial. In der Literatur sind häufig verschiedene Begriffe und Klassifizierungen zu finden, in vielen Fällen jedoch ohne klare Definitionen oder Richtlinien wie sie zu benutzen sind oder wie sie experimentell unterschieden werden können. Ziel dieses Kurzaufsatzes ist es, die existierenden Konzepte mithilfe jüngster Literatur zu klassifizieren, differenzieren und zu korrelieren. Dadurch soll der Leser eine generelle Einsicht in thermodynamische und kinetische Aspekte komplexer supramolekularer Polymerisationsprozesse erhalten. Ein gutes Verständnis dieser Begriffe und Konzepte sollte dazu beitragen, neue, komplexe, funktionale Materialien zu erschaffen.     

A Vesicle‐to‐Worm Transition Provides a New High‐Temperature Oil Thickening Mechanism

Diblock copolymer vesicles are prepared via RAFT dispersion polymerization directly in mineral oil. Such vesicles undergo a vesicle‐to‐worm transition on heating to 150 °C, as judged by TEM and SAXS. Variable‐temperature ¹H NMR spectroscopy indicates that this transition is the result of surface plasticization of the membrane‐forming block by hot solvent, effectively increasing the volume fraction of the stabilizer block and so reducing the packing parameter for the copolymer chains. The rheological behavior of a 10 % w/w copolymer dispersion in mineral oil is strongly temperature‐dependent: the storage modulus increases by five orders of magnitude on heating above the critical gelation temperature of 135 °C, as the non‐interacting vesicles are converted into weakly interacting worms. SAXS studies indicate that, on average, three worms are formed per vesicle. Such vesicle‐to‐worm transitions offer an interesting new mechanism for the high‐temperature thickening of oils.     

Systemic Brain Delivery of Antisense Oligonucleotides across the Blood–Brain Barrier with a Glucose-Coated Polymeric Nanocarrier

Current antisense oligonucleotide (ASO) therapies for the treatment of central nervous system (CNS) disorders are performed through invasive administration, thereby placing a major burden on patients. To alleviate this burden, we herein report systemic ASO delivery to the brain by crossing the blood–brain barrier using glycemic control as an external trigger. Glucose-coated polymeric nanocarriers, which can be bound by glucose transporter-1 expressed on the brain capillary endothelial cells, are designed for stable encapsulation of ASOs, with a particle size of about 45 nm and an adequate glucose-ligand density. The optimized nanocarrier efficiently accumulates in the brain tissue 1 h after intravenous administration and exhibits significant knockdown of a target long non-coding RNA in various brain regions, including the cerebral cortex and hippocampus. These results demonstrate that the glucose-modified polymeric nanocarriers enable noninvasive ASO administration to the brain for the treatment of CNS disorders.     

Theranostic Layer-by-Layer Nanoparticles for Simultaneous Tumor Detection and Gene Silencing

Layer-by-layer nanoparticles (NPs) are modular drug delivery vehicles that incorporate multiple functional materials through sequential deposition of polyelectrolytes onto charged nanoparticle cores. Herein, we combined the multicomponent features and tumor targeting capabilities of layer-by-layer assembly with functional biosensing peptides to create a new class of nanotheranostics. These NPs encapsulate a high weight percentage of siRNA while also carrying a synthetic biosensing peptide on the surface that is cleaved into a urinary reporter upon exposure to specific proteases overexpressed in the tumor microenvironment. Importantly, this biosensor reports back on a molecular signature characteristic to metastatic tumors and associated with poor prognosis, MMP9 protease overexpression. This nanotheranostic mediates noninvasive urinary-based diagnostics in mouse models of three different cancers with simultaneous gene silencing in flank and metastatic mouse models of ovarian cancer.