Emulsion-Assisted Polymerization-Induced Hierarchical Self-Assembly of Giant Sea Urchin-like Aggregates on a Large Scale.

Hierarchical solution self-assembly has become an important biomimetic method to prepare highly complex and multifunctional supramolecular structures. However, despite great progress, it is still highly challenging to prepare hierarchical self-assemblies on a large scale because the self-assembly processes are generally performed at high dilution. Now, an emulsion-assisted polymerization-induced self-assembly (EAPISA) method with the advantages of in situ self-assembly, scalable preparation, and facile functionalization was used to prepare hierarchical multiscale sea urchin-like aggregates (SUAs). The obtained SUAs from amphiphilic alternating copolymers have a micrometer-sized rattan ball-like capsule (RBC) acting as the hollow core body and radiating nanotubes tens of micrometers in length as the hollow spines. They can capture model proteins effectively at an ultra-low concentration (ca. 10 nm) after functionalization with amino groups through click copolymerization.

Construction of Light-Harvesting Polymeric Vesicles in Aqueous Solution with Spatially Separated Donors and Acceptors.

This communication describes polymer vesicles self-assembled from hyperbranched polymers (branched polymersomes (BPs)) as scaffolds, conceptually mimicking the natural light-harvesting system in aqueous solution. The system is constructed with hydrophobic 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl) as donors encapsulated in the hydrophobic hyperbranched cores of the vesicles and the hydrophilic Rhodamine B (RB) as acceptors incorporated on the surface of the vesicles through the cyclodextrin (CD)/RB host-guest interactions, through which the donors and acceptors are spatially separated to effectively avoid the self-quenching between donors. This vesicular light harvesting system has presented good energy transfer efficiency of about 80% in water, and can be used as the ink to write multiclolor letters. In addition, due to the giant dimension of BPs, the real-time fluorescent images of the vesicles under an optical microscope can be observed to prove the light-harvesting process. It is supposed that such a vesicular light-harvesting antenna can be used to construct artificial photosynthesis systems in the future.

Chain Packing and Its Anomalous Effect on Mechanical Toughness for Poly(lactic acid).

The effect of chain packing on tensile properties was studied employing amorphous poly(lactic acid) PLA. It was found that the samples cooled in the temperature range from 60 to 80 °C, that is, slightly higher than the glass transition temperature Tg, showed ductile behavior with a low brittle-ductile transition temperature. Furthermore, the samples obtained by prolonged cooling at 56 °C also showed ductile behavior, whereas a shorter cooling time at the same temperature provided a brittle product. Even for the samples quenched at 40 °C, they showed ductile behavior after the exposure to postprocessing annealing operation at 60 °C; that is, the strain at break is larger than 3. This is an anomalous phenomenon for a glassy polymer. The dynamic mechanical analysis and thermal characterization revealed that the ductile samples show slightly higher Tg than the brittle ones, presumably due to high packing density of polymer chains. Moreover, it was found from infrared spectroscopy that the ductile samples show strong absorbance at 1267 cm(-1), ascribed to high energy gauche-gauche gg conformers. Following the classic Robertson's descriptions of plastic flow, it is concluded that the increase in the gauche-gauche gg conformers, which shows the conformation change under a low stress level, reduces the critical onset stress for shear yielding. The results demonstrated that the mechanical toughness of PLA can be controlled by the cooling conditions during processing and the postprocessing annealing operation.

A novel combined therapeutic strategy of Nano-EN-IR@Lip mediated photothermal therapy and stem cell inhibition for gastric cancer.

Recurrence and metastasis of gastric cancer is a major therapeutic challenge for treatment. The presence of cancer stem cells (CSCs) is a major obstacle to the success of current cancer therapy, often leading to treatment resistance and tumor recurrence and metastasis. Therefore, it is important to develop effective strategies to eradicate CSCs. In this study, we developed a combined therapeutic strategy of photothermal therapy (PTT) and gastric cancer stem cells (GCSCs) inhibition by successfully synthesizing nanoliposomes loaded with IR780 (photosensitizer) and EN4 (c-Myc inhibitor). The nanocomposites are biocompatible and exhibit superior photoacoustic (PA) imaging properties. Under laser irradiation, IR780-mediated PTT effectively and rapidly killed tumor cells, while EN4 synergistically inhibited the self-renewal and stemness of GCSCs by suppressing the expression and activity of the pluripotent transcription factor c-Myc, preventing the tumor progression of gastric cancer. This Nano-EN-IR@Lip is expected to be a novel clinical nanomedicine for the integration of gastric cancer diagnosis, treatment and prevention.

CuI/1,10-phen/PEG promoted decarboxylation of 2,3-diarylacrylic acids: synthesis of stilbenes under neutral and microwave conditions with an in situ generated recyclable catalyst.

A series of trans- or cis-stilbenes have been synthesized in good to excellent yields via a functional group-dependent decarboxylation process from the corresponding 2,3-diaryl acrylic acids in a neutral CuI/1,10-phen/PEG-400 system under microwave conditions. The in situ generation of the recyclable catalytic complex, the use of environmentally benign solvent PEG-400, the operational simplicity, the short reaction times, as well as the functional group-dependent chemo- and stereo-selectivity have made the decarboxylation process a highly efficient and applicable protocol.

Sprayable hydrogel for biomedical applications.

Polymeric hydrogels have extraordinary potential to be utilized for biomedical applications. Recently, sprayable hydrogels have received increasing attention for their biocompatibility, degradability, tunable mechanical properties and rapid spray-filming abilities. In this review, hydrogel-based biomaterials, especially those based on natural polymers, such as polysaccharides and proteins, have been explained. The focus of this review lies on illuminating recent advances in sprayable hydrogel systems and highlighting the properties and applications of sprayable hydrogels, such as wound management, postoperative adhesion and cancer therapeutics. In addition, future research directions and challenges are also discussed.

Bioinspired Ultrastrong Solid Electrolytes with Fast Proton Conduction along 2D Channels.

Solid electrolytes have attracted much attention due to their great prospects in a number of energy- and environment-related applications including fuel cells. Fast ion transport and superior mechanical properties of solid electrolytes are both of critical significance for these devices to operate with high efficiency and long-term stability. To address a common tradeoff relationship between ionic conductivity and mechanical properties, electrolyte membranes with proton-conducting 2D channels and nacre-inspired architecture are reported. An unprecedented combination of high proton conductivity (326 mS cm-1 at 80 °C) and superior mechanical properties (tensile strength of 250 MPa) are achieved due to the integration of exceptionally continuous 2D channels and nacre-inspired brick-and-mortar architecture into one materials system. Moreover, the membrane exhibits higher power density than Nafion 212 membrane, but with a comparative weight of only ≈0.1, indicating potential savings in system weight and cost. Considering the extraordinary properties and independent tunability of ion conduction and mechanical properties, this bioinspired approach may pave the way for the design of next-generation high-performance solid electrolytes with nacre-like architecture.