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Lipid nanoparticle‐based drug delivery systems have a profound clinical impact on nucleic acid‐based therapy and vaccination. Recombinant human insulin, a negatively‐charged biomolecule like mRNA, may also be delivered by rationally‐designed positively‐charged lipid nanoparticles with glucose‐sensing elements and be released in a glucose‐responsive manner. Herein, we have designed phenylboronic acid‐based quaternary amine‐type cationic lipids that can self‐assemble into spherical lipid nanoparticles in an aqueous solution. Upon mixing insulin and the lipid nanoparticles, a heterostructured insulin complex is formed immediately arising from the electrostatic attraction. In a hyperglycemia‐relevant glucose solution, lipid nanoparticles become less positively charged over time, leading to reduced attraction and subsequent insulin release. Compared with native insulin, this lipid nanoparticle‐based glucose‐responsive insulin shows prolonged blood glucose regulation ability and blood glucose‐triggered insulin release in a type 1 diabetic mouse model. [ABSTRACT FROM AUTHOR]

Protein and peptide drugs are predominantly administered by injection to achieve high bioavailability, but this greatly compromises patient compliance. Oral and transdermal drug delivery with minimal invasiveness and high adherence represent attractive alternatives to injection administration. However, oral and transdermal administration of bioactive proteins must overcome biological barriers, namely the gastrointestinal and skin barriers, respectively. The rapid development of new materials and technologies promises to address these physiological obstacles. This review provides an overview of the latest advances in oral and transdermal protein delivery, including chemical strategies, synthetic nanoparticles, medical microdevices, and biomimetic systems for oral administration, as well as chemical enhancers, physical approaches, and microneedles in transdermal delivery. We also discuss challenges and future perspectives of the field with a focus on innovation and translation. [ABSTRACT FROM AUTHOR]

The synthesis of crystalline polymer with a well‐defined orientated state and a two‐dimensional crystalline size beyond a micrometer will be essential to achieve the highest physical feature of polymer material but remain challenging. Herein, we show the synthesis of the crystalline unipolymer monolayer with an unusual ultrahigh modulus that is higher than the ITO substrate and high conductance by simultaneous electrosynthesis and manipulation. We find that the polymer monolayer has fully extended in the vertical and unidirectional orientation, which is proposed to approach their theoretically highest density, modulus, and conductivity among all aggregation formations of the current polymer. The modulus and current density can reach 40 and 1000 times higher than their amorphous counterpart. It is also found that these monolayers exhibit the bias‐ and length‐dependent multiple charge states and asymmetrically negative differential resistance (NDR) effect, indicating that this unique molecular tailoring and ordering design is promising for multilevel resistive memory devices. Our work demonstrates the creation of a crystalline polymer monolayer for approaching the physical limit of polymer electronic materials and also provides an opportunity to challenge the synthetically iterative limit of an isolated ultra‐long polymer. [ABSTRACT FROM AUTHOR]

We present herein the vertical step‐growth polymerization of a monomer A‐B through individual A–A or B–B coupling driven by electrochemical switching of positive and negative bias on a self‐assembled A or B electrode. The monomer RuII(bda)AB (bda=2,2′‐bipyridine‐6,6′‐dicarboxylate), in which A and B are pyridine moieties with pendant carbazolyl and vinyl groups, could be dimerized at oxidative (ca. 1.0 V vs. Ag/Ag+) or reductive potential (ca. −1.8 V) to give a self‐assembled RuII(bda)PA or RuII(bda)PB monolayer (P=pyridine with a pendant phosphonic acid) on ITO glass. This polymerization enabled the sequence‐ and topology‐controlled synthesis of surface‐confined molecular wires with single‐molecule precision on an electrode. The electrocatalytic performance of the vertically orientated molecular wires for water oxidation increased with increasing molecular length and exceeded that of both the self‐assembled monolayer and a randomly electropolymerized film, which have previously been studied as typical models. A step up: Vertical step‐growth polymerization of a monomer A‐B through individual A–A and B–B coupling reactions driven by electrochemically positive and negative bias on a self‐assembled A or B electrode enabled the sequence‐ and topology‐controlled synthesis of molecular wires with single‐molecule precision (see picture). The resulting surface‐confined molecular wires showed fast electron transfer and excellent electrocatalytic performance. [ABSTRACT FROM AUTHOR]