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Improving bioavailability of orally delivered drugs is still challenging, as conventional drug delivery systems suffer from non-specific drug delivery in the gastrointestinal (GI) tract and limited drug absorption efficiency. Gastric drug delivery is even more difficult due to the harsh microenvironment, short retention time, and physiologic barriers in the stomach. Here, an oral drug delivery microcapsule system was developed for gastric drug delivery, which consists of ionic liquid (IL) as the inner carrier and metal-phenolic network (MPN) as the microcapsule shell. The IL@MPN microcapsules are prepared by interfacial self-assembly of Fe

Porous polymer scaffolds are essential materials for tissue engineering because they can be easily processed to deliver stem cells or bioactive factors. However, scaffolds made of synthetic polymers normally lack a bioactive cell-material interface and undergo a burst release of growth factors, which may hinder their further application in tissue engineering. In this paper, a metal-phenolic network (MPN) was interfacially constructed on the pore surface of a porous poly(dl-lactide) (PPLA) scaffold. Based on the molecular gating property of the MPN supramolecular structure, the PPLA@MPN scaffold achieved the sustained release of the loaded molecules. In addition, the MPN coating provided a bioactive interface, thus encouraging the migration and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). The PPLA@MPN scaffolds exhibited enhanced bone regeneration in a rat femoral defect model in vivo compared to PPLA, which is ascribed to the combined effect of sustained bone morphogenetic protein-2 (BMP-2) release and the osteogenic ability of MPN. This nanodressing technique provides a viable and straightforward strategy for enhancing the performance of porous polymer scaffolds in bone tissue engineering.

In this work, the azobenzene group-containing carboxylic acid salt azobenzene-4,4′-dicarboxylate disodium salt (ADDS) was selected as the dopant for the controlled synthesis of nanostructured polypyrrole (PPy). By controlling the cis-trans configuration of ADDS (via ultraviolet light irradiation) as well as the concentration of divalent ADDS anion (via the medium pH alteration), a series of ADDS-doped PPy hydrogels with different morphologies and electrical properties were prepared accordingly. Under weak alkaline conditions (pH = 8.0), the morphology of the resulting PPy changes from nanofiber (nanobelt) to nanoflake and then to granular structure when the exposure time of ADDS aqueous solution to the UV-light irradiation was extended step by step from 0 to 15 min. This phenomenon is mainly due to the gradual decrease of the trans isomers in ADDS aqueous solution. Under visible light conditions, the morphology of the resulting PPy transforms from nanofiber (nanobelt) to granular structure when the pH of ADDS aqueous solution was varied from pH 8.0 to pH 3.0. This phenomenon is mainly due to the gradual decrease of the divalent doping anions (all trans isomers). Since trans ADDS isomers are co-planar linear molecules, and under weakly alkaline conditions, ADDS exists mainly in the form of divalent anion, the conductivity of PPy doped with all-trans ADDS (10.4 S cm-1) is therefore higher than that of PPy doped with UV-light irradiated ADDS (some trans isomers are transformed to the corresponding cis isomers) (1.0 S cm-1). It can be concluded that the morphologies and the electrical properties of ADDS-doped polypyrrole conducting hydrogels can be tuned just by varying the UV irradiation time and the medium pH, which results in the change of the steric configuration and the existing form of ADDS. The present new strategy is helpful for the controlled synthesis of conducting polymer hydrogels.

Water transmission of pathogenic microorganisms can lead to infectious diseases and potential pandemics. Piezocatalysis is an emerging technology for water disinfection, however, current piezocatalysts often have low catalytic performance due to limited charge utilization and require the use of high-frequency ultrasound. Herein, low-frequency hydromechanics is employed as mechanical energy resource to achieve efficient disinfection via a rationally-designed piezocatalyst, BaTiO3@Au. The interfacial position of Au cocatalyst was optimized by in situ piezodeposition instead of random chemical reduction, which facilitated charge separation and promoted the generation of reactive oxygen species (ROS). By simply vibrating (e.g., stirring) the piezocatalysts dispersed in aqueous solution, efficient degradation of organic molecules as well as inactivation of model bacteria and virus could be obtained. This approach allowed us to take advantage of low-frequency hydromechanical energy to significantly reduce intestinal pathogenic bacteria and total organic carbon content in hospital wastewater, which could provide a green and feasible way for water disinfection.

In this work, a novel functionalized organic salt − anilinium saccharinate ([HANI][Sac]) was synthesized by the ion exchange method, and its composition and properties were characterized by 1H NMR, 13C NMR, ESI/MS and TG-DSC techniques. [HANI][Sac] can be used as both monomer and supporting electrolyte for efficient electrosynthesis of polyaniline (PANI) in acetonitrile. The obtained PANI has hierarchical porous structure and its doping degree with saccharinate anion ([Sac]-) is as high as 33.5%. The resulting [Sac]--doped-PANI (PANI-[Sac]) can be used as an electrochemically controlled drug delivery system. The in vitro release kinetics of [Sac]- under different potential stimuli conditions showed that, at a given time, the release rate of [Sac]- and its release percentage (ratio of the amount released to that loaded) increase with the negative shift of the applied potential. The amount of [Sac]- loaded and/or released can also be regulated by varying the charge for PANI electropolymerization. The present work provides a new strategy for the facile construction of conducting polymer-based electrochemically controlled drug release system.