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Underwater superaerophobic surface is of great significance for controllable manipulation of gas bubbles in scientific research and practical applications. However, the fabrication of arbitrary-shaped superaerophobic solid surfaces through a simple and low-cost approach is still hard. Herein, superaerophobic 3D objects were manufactured via liquid crystal display (LCD)-based 3D printing (vat photopolymerisation-based additive manufacturing) combined with one-step post-surface-treatment in sodium hydroxide (NaOH) solution. The influences of NaOH concentration, reaction temperature and time on the wettability of the polymer surface were systematically investigated. After a suitable alkali-treatment, the object surface obtained a bubble contact angle of 159° with extremely low bubble adhesion, featuring the underwater superaerophobicity. Morphology and composition characterisation demonstrated that a hydrophilic gel layer was produced on the printed sheet after the alkali-treatment, which is explained as the main mechanism of the superwetting transition from aerophobicity to superaerophobicity. Interestingly, spontaneously formed surface microgrids (size in xy direction: ∼50 μm) during 3D printing accelerated the alkali-treatment. Further, a superaerophobic 3D tweezer was designed, fabricated, and successfully applied in a toxic nitric oxide (NO) bubble reaction underwater for gas purity detection. The one-step post-surface-treatment method is also suitable for other commercial photosensitive resins and digital-light-processing (DLP) 3D printing.

Biomolecular self-assembly provides a potential way for the design and synthesis of functional biomaterials with uniform structure and unique properties, in which the self-assembly of peptide molecules is especially important ascribed to the controllable structural design and functional tailoring of peptide motifs. The self-assembly of peptides can be instructed by internal and external physical, chemical, and biological stimulations. Compared to both physical and chemical stimulations including light/thermal treatment, pH/ionic strength adjustment, and others, the biological mediation with enzymes exhibited great advantages due to its high bioactivity, excellent biocompatibility, high specificity, and in vivo reaction. Herein we summarize the advance in the enzyme-instructed peptide self-assembly for biomedical applications. For this aim, we introduce and discuss the self-assembly of peptide that controlled by both kinetics and dynamics, and then demonstrate the enzyme-induced preparation of peptide nanostructures such as nanofibers, nanotubes, vesicles, networks, and hydrogels. Finally, the biomedical applications of enzyme-induced self-assembled peptide nanomaterials for cancer diagnostics, cancer therapy, bioelectronic devices, and biosensors are presented. It is expected this work will inspire more studies on the using of bioactive enzymes for triggering the self-assembly of peptides to create various novel bionanomaterials, which could extend this interesting research field to others such as tissue engineering, biocatalysis, energy storage, and environmental science.

Light-responsive hydrogel actuators show attractive biomedical applications for in vivo drug delivery tool, surgical tissue repair operation, and vascular cleaning due to its non-contact, rapid, precise, and remote spatial control of light. Conventional visible–light–responsive hydrogels contain special chemical structure or groups, and the difficulty in synthesis results in that few can be applied to fabricate visible–light–driven hydrogel actuators. In this study, based on photothermal effect, surface-modified Fe3O4 nanoparticles were incorporated into poly(N-isopropylacrylamide-acrylamide) hydrogel by UV photopolymerization, which revealed excellent green–light–responsive volume change. Under a laser irradiation of 200 mW at 520 nm, the bending angle deformation of hydrogel strips with 2.62 wt% Fe3O4 reached 107.8°. Strip-shaped hydrogel actuators could be applied to transport tiny objects. Furthermore, a boomerang-like hydrogel actuator was designed and fabricated to drive floating foam on water. By 12 cycles of continuous laser on–off irradiation to a hydrogel actuator underwater, a circular returning movement of the float was accomplished. The study on driving a float using visible–light–triggered hydrogel actuators provides a new idea for the design of light-driven biomedical devices and soft robots.

Summary: Ascorbic acid-glutathione (AsA-GSH) cycle represents important antioxidant defense system in planta. Here we utilized Oncidium cytosolic ascorbate peroxidase (OgCytAPX) as a model to demonstrate that CytAPX of several plants possess dual catalytic activity of both AsA and GSH, compared with the monocatalytic activity of Arabidopsis APX (AtCytAPX). Structural modeling and site-directed mutagenesis identified that three amino acid residues, Pro63, Asp75, and Tyr97, are required for oxidization of GSH in dual substrate catalytic type. Enzyme kinetic study suggested that AsA and GSH active sites are distinctly located in cytosolic APX structure. Isothermal titration calorimetric and UV-visible analysis confirmed that cytosolic APX is a heme-containing protein, which catalyzes glutathione in addition to ascorbate. Biochemical and physiological evidences of transgenic Arabidopsis overexpressing OgCytAPX1 exhibits efficient reactive oxygen species-scavenging activity, salt and heat tolerances, and early flowering, compared with Arabidopsis overexpressing AtCytAPX. Thus results on dual activity CytAPX impose significant advantage on evolutionary adaptive mechanism in planta. : Plant Biochemistry; Plant Biology; Plant Evolution Subject Areas: Plant Biochemistry, Plant Biology, Plant Evolution

Cytoplasmic PTEN is a tumor suppressor that antagonises PI3K signalling. Here, the authors show that nuclear PTEN can interact with the spliceosomal proteins and drive pre-mRNA splicing in a phosphatase-independent manner, in particular, PTEN depletion promotes Golgi extension and secretion through GOLGA2 exon skipping.

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As important factors to oolong tea quality, the accumulation and dynamic change in aroma substances attracts great attention. The volatile composition of oolong tea is closely related to the precursor contents. Fatty acids (FAs) and their derivatives are basic components of oolong tea fragrance during the postharvest process. However, information about the precursors of FAs during the postharvest process of oolong tea production is rare. To investigate the transformation of fatty acids during the process of oolong tea production, gas chromatograph–flame ionization detection (GC-FID) was conducted to analyze the composition of FAs. The results show that the content of total polyunsaturated FAs initially increased and then decreased. Specifically, the contents of α-linolenic acid, linoleic acid and other representative substances decreased after the turn-over process of oolong tea production. The results of partial least squares discrimination analysis (PLS-DA) showed that five types of FAs were obviously impacted by the processing methods of oolong tea (VIP > 1.0). LOX (Lipoxygenase, EC 1.13.11.12) is considered one of the key rate-limiting enzymes of long-chain unsaturated FAs in the LOX-HPL (hydroperoxide lyase) pathway, and the mechanical wounding occurring during the postharvest process of oolong tea production greatly elevated the activity of LOX.