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Dynamic polymer hydrogels with an environmental adaptive self-healing ability and dual responsive sol–gel transitions were prepared by combining acylhydrazone and disulfide bonds together in the same system. The hydrogel can automatically repair damage to it under both acidic (pH 3 and 6) and basic (pH 9) conditions through acylhydrazone exchange or disulfide exchange reactions. However, the hydrogel is not self-healable at pH 7 because both bonds are kinetically locked, whereas the hydrogel gains self-healing ability by accelerating acylhydrazone exchange with the help of catalytic aniline. All of the self-healing processes are demonstrated to be effective without an external stimulus at room temperature in air. The hydrogel also displays unique reversible sol–gel transitions in response to both pH (HCl/triethylamine) and redox (DTT/H2O2) triggers.

Background and purposeStroke is the leading cause of mortality and disability in China. Precise aetiological classification, imaging and biological markers may predict the prognosis of stroke. The Third China National Stroke Registry (CNSR-III), a nationwide registry of ischaemic stroke or transient ischaemic attack (TIA) in China based on aetiology, imaging and biology markers, will be considered to clarify the pathogenesis and prognostic factors of ischaemic stroke.MethodsBetween August 2015 and March 2018, the CNSR-III recruited consecutive patients with ischaemic stroke or TIA from 201 hospitals that cover 22 provinces and four municipalities in China. Clinical data were collected prospectively using an electronic data capture system by face-to-face interviews. Patients were followed for clinical outcomes at 3 months, 6 months and 1–5 year annually. Brain imaging, including brain MRI and CT, were completed at baseline. Blood samples were collected and biomarkers were tested at baseline.ResultsA total of 15 166 stroke patients were enrolled, among which 31.7% patients were women with the average age of 62.2±11.3 years. Ischaemic stroke was predominant (93.3%, n=14 146) and 1020 (6.7%) TIAs were enrolled.ConclusionsCNSR-III is a large scale nationwide registry in China. Data from this prospective registry may provide opportunity to evaluate imaging and biomarker prognostic determinants of stroke.

The Heck coupling reaction between organic halides and vinylbenzene compounds was utilized to synthesize soluble and fusible conjugated polymers. Compared to other approaches, the Heck reaction offers an easier way to prepare processible poly(phenylenevinylenes). The fusibility of the alkoxy substituted poly(phenylenevinylene) enables us to observe the nematic liquid crystalline phase above the melting temperature.

Presented in this communication is a novel hybrid vesicle with a cross-linked polyorganosiloxane wall based on a new reactive block copolymer, poly(ethylene oxide)-block-poly(3-(trimethoxysilyl)propyl methacrylate) (PEO-b-PTMSPMA), which was synthesized by atom transfer radical polymerization. The vesicles were prepared first by self-assembly of the block copolymer in a selective solvent, and then the PTMSPMA block was subjected to hydrolysis and polycondensation reaction to fix vesicle wall in the presence of triethylamine as a catalyst. Transmission electron microscopy, scanning electron microscopy, NMR, and light scattering have been used to characterize the vesicles.

In a previous communication, we have reported the study of novel organic/inorganic hollow particles based on a reactive amphiphilic diblock copolymer, poly(ethylene oxide)-block-poly [3-(trimethoxysilyl)propyl methacrylate] (PEO-b-PTMSPMA). The preparation of these novel particles involved the preformed vesicles of the block copolymers in a methanol/water solvent mixture, followed by a gelation process to fix the vesicular morphology. In this paper, the detailed conditions for the preparations of the hybrid vesicles, including water contents in the binary solvent, initial copolymer concentration (C ini) in methanol, compositions of the diblock copolymers, and gelation catalyst, have been explored in great detail. The results demonstrated that the robust vesicles could be prepared under a variety of conditions, such as over a broader range of the water content (from ca. 34 to 98.4 wt %) at the Cini of 5.0 mg/mL for PEO45-b-PTMSPMA59. Furthermore, exclusive vesicles were formed under the Cini ranging from 0.5 to 20 mg/mL of PEO45-b-PTMSPMA59 in methanol while the water content was kept constant at 55.8 wt %, whereas the average size of vesicles and the size distribution increased correspondingly. Before the exclusive vesicles appeared, spheres, short rods, and lamellae were observed as the coexisted morphologies when the water content increased gradually. For the block copolymers with a constant PEO length and different PTMSPMA lengths, i.e., PEO 45-b-PTMSPMAx (x ) 29, 42, and 180), only vesicles were produced under the conditions applied with the longer PTMSPMA blocks resulting in a thicker vesicle wall. The gelation catalyst plays a critical role in the morphological fixation. We have found that triethylamine (TEA) was the best gelation catalyst under the conditions used in this study, while the acid catalysts destroyed the vesicles. In addition, because of the inorganic components, the nanocapsule was very stable, and its morphology remained even after calcination at 450°C.

Secret chambers: Organic–inorganic hybrid nanoparticles (see picture) with a complex hollow structure were prepared by the self‐assembly of a reactive block copolymer, poly(ethylene oxide)‐block‐poly[3‐(trimethoxysilyl)propyl methacrylate], in DMF/water. Within these hybrid large‐compound vesicles, several cavities are separated by crosslinked hybrid bilayers of uniform thickness.

Shaped hairy polymer nanoobjects are defined as a kind of polymeric particles with persistent geometric shape and densely tethered polymer hairs. Their size, at least in one dimension, should not exceed 100 nm. Components of the nanoobjects are mainly organic polymers, and therefore, they exhibit viscoelasticity and stimuli responsibility in general. Namely, they are soft nanomatter, greatly differing from those stiff and rigid inorganic nanoparticles. While spherical polymeric nanoparticles have been studied intensively, much less attention has been paid to those nonspherical hairy polymer nanoparticles like cylindrical and lamellar ones. The reasons are because fabrication of the shaped soft nanoparticles is still difficult and also less information has been known about the shape-induced properties, especially in biomedical application. In recent years, scientists are realizing that the shape of nanoparticles does matter to their properties of plasma circulation in mice and cell uptake, revealing a nearly unexplored area. In this Perspective, the author would like to focus on these soft nanoobjects with shapes and tethered polymeric hairs by introducing how to shape them, to densely tether polymer hairs, and why the hair and the shape are important.