Fusion gene 4CL-CCR promotes lignification in tobacco suspension cells.

KEY MESSAGE: The fusion gene 4CL-CCR promotes lignification and activates lignin-related MYB expression in tobacco but inhibits auxin-related gene expression and hinders the auxin absorption of cells. Given the importance of lignin polymers in plant growth and their industrial value, it is necessary to investigate how plants synthesize monolignols and regulate the level of lignin in cell walls. In our previous study, expression of the Populus tomentosa fusion gene 4CL-CCR significantly promoted the production of 4-hydroxycinnamyl alcohols. However, the function of 4CL-CCR in organisms remains poorly understood. In this study, the fusion gene 4CL-CCR was heterologously expressed in tobacco suspension cells. We found that the transgenic suspension cells exhibited lignification earlier. Furthermore, 4CL-CCR significantly reduced the content of phenolic acids and increased the content of aldehydes in the medium, which led to an increase in lignin deposition. Moreover, transcriptome results showed that the genes related to lignin synthesis, such as PAL, 4CL, CCoAOMT and CAD, were significantly upregulated in the 4CL-CCR group. The expression of genes related to auxin, such as ARF3, ARF5 and ARF6, was significantly downregulated. The downregulation of auxin affected the expression of transcription factor MYBs. We hypothesize that the upregulated genes MYB306 and MYB315 are involved in the regulation of cell morphogenesis and lignin biosynthesis and eventually enhance lignification in tobacco suspension cells. Our findings provide insight into the function of 4CL-CCR in lignification and how secondary cell walls are formed in plants.

Characterization of a novel recombinant halophilic ß-glucosidase of Trichoderma harzianum derived from Hainan mangrove.

BACKGROUND: ß-glucosidase is an important biomass-degrading enzyme and plays a vital role in generating renewable biofuels through enzymatic saccharification. In this study, we analyzed the transcriptome of Trichoderma harzianum HTASA derived from Hainan mangrove and identified a new gene encoding ß-glucosidase Bgl3HB. And the biochemically characterization of ß-glucosidase activity was performed. RESULTS: Bgl3HB showed substantial catalytic activity in the pH range of 3.0-5.0 and at temperatures of 40 ℃-60 ℃. The enzyme was found quite stable at 50 ℃ with a loss of only 33.4% relative activity after 240 min of heat exposure. In addition, all tested metal ions were found to promote the enzyme activity. The ß-glucosidase activity of Bgl3HB was enhanced by 2.12-fold of its original activity in the presence of 5 M NaCl. Surprisingly, Bgl3HB also showed a remarkable ability to hydrolyze laminarin compared to other measured substrates. Enzyme efficiency was examined in the sugarcane bagasse saccharification processes, in which Bgl3HB with 5 M NaCl worked better supplementing Celluclast 1.5L than the commercial Novozyme 188 ascertained it as an admirably suited biocatalyst for the utilization of agricultural waste. In this work, this is the first report of a halophilic ß-glucosidase from Trichoderma harzianum, and represents the ß-glucosidase with the highest known NaCl activation concentration. And adding 5 M NaCl could enhance saccharification performance even better than commercial cellulase. CONCLUSIONS: These results show that Bgl3HB has great promise as a highly stable and highly efficient cellulase with important future applications in the industrial production of biofuels.

Liposomal short-chain C6 ceramide induces potent anti-osteosarcoma activity in vitro and in vivo.

Osteosarcoma (OS) remains one deadly disease for many affected patients. The search for novel and more efficient anti-OS agents is urgent. In the current study, we demonstrated that liposome-packed C6 ceramide exerted potent cytotoxic effect against established (U2OS and MG-63 lines) and primary human OS cells. Meanwhile, the liposomal C6 (ceramide) induced caspase-mediated apoptotic death in OS cells. Liposomal C6 was significantly more potent than conventional free C6 in inhibiting OS cells, yet it was safe to non-cancerous bone cells (primary murine osteoblasts or human MLO-Y4 osteocytic cells). At the signaling level, we showed that liposomal C6 potently inhibited Akt activation in OS cells. Further studies revealed that a low dose of liposomal C6 dramatically sensitized the in vitro anti-OS activity of two conventional chemodrugs: methotrexate (MTX) and doxorubicin. In vivo, intravenous injection of liposomal C6 inhibited Akt activation and suppressed U2OS xenograft growth in nude mice without causing apparent toxicities. Meanwhile, when given at a low-dose (5 mg/kg body weight), liposomal C6 dramatically sensitized MTX's anti-U2OS activity in vivo. Collectively, our data demonstrate that liposomal C6 exerts potent anti-tumor activity in preclinical OS models.

Exploring the role of the LkABCG36 transporter in lignin accumulation.

Lignin is a complex biopolymer formed through the condensation of three monomeric precursors known as monolignols. However, the mechanism underlying lignin precursor transport remains elusive, with uncertainty over whether it occurs through passive diffusion or an active energized process. ATP-binding cassette 36 (ABCG36) plays important roles in abiotic stress resistance. In this study, we investigated the transport functions of LkABCG36 (Larix kaempferi) for lignin precursors and the potential effects of LkABCG36 overexpression in plants. LkABCG36 enhanced the ability of tobacco (Nicotiana tabacum) bright yellow-2 (BY-2) cells to resist monolignol alcohol stress. Furthermore, LkABCG36 overexpression promoted lignin deposition in tobacco plant stem tissue. To understand the underlying mechanism, we measured the BY-2 cell ability to export lignin monomers and the uptake of monolignol precursors in inside-out (inverted) plasma membrane vesicles. We found that the transport of coniferyl and sinapyl alcohols is an ATP-dependent process. Our data suggest that LkABCG36 contributes to lignin accumulation in tobacco stem tissues through a mechanism involving the active transport of lignin precursors to the cell wall. These findings shed light on the lignin biosynthesis process, with important implications for enhancing lignin deposition in plants, potentially leading to improved stress tolerance and biomass production.

Targeted Ferroptosis-Immunotherapy Synergy: Enhanced Antiglioma Efficacy with Hybrid Nanovesicles Comprising NK Cell-Derived Exosomes and RSL3-Loaded Liposomes.

Ferroptosis therapy and immunotherapy have been widely used in cancer treatment. However, nonselective induction of ferroptosis in tumors is prone to immunosuppression, limiting the therapeutic effect of ferroptosis cancer treatment. To address this issue, this study reports a customized hybrid nanovesicle composed of NK cell-derived extracellular versicles and RSL3-loaded liposomes (hNRVs), aiming to establish a positive cycle between ferroptosis therapy and immunotherapy. Thanks to the enhanced permeability and retention effect and the tumor homing characteristics of NK exosomes, our data indicate that hNRVs can actively accumulate in tumors and enhance cellular uptake. FASL, IFN-γ, and RSL3 are released into the tumor microenvironment, where FASL derived from NK cells effectively lyses tumor cells. RSL3 downregulates the expression of GPX4 in the tumor, leading to the accumulation of LPO and ROS, and promotes ferroptosis in tumor cells. The accumulation of IFN-γ and TNF-α stimulates the maturation of dendritic cells and effectively induces the inactivation of GPX4, promoting lipid peroxidation, making them sensitive to ferroptosis and indirectly promoting the occurrence of ferroptosis. This study highlights the role of the customized hNRV platform in enhancing the effectiveness of synergistic treatment with selective delivery of ferroptosis inducers and immune activation against glioma without causing additional side effects on healthy organs.

Reducing cherry rain-cracking: Enhanced wetting and barrier properties of chitosan hydrochloride-based coating with dual nanoparticles.

The synergistic effects of phosphorylated zein nanoparticles (PZNP) and cellulose nanocrystals (CNC) in enhancing the wetting and barrier properties of chitosan hydrochloride (CHC)-based coating are investigated characterized by Fourier Transform Infrared Spectra (FTIR), X-ray Diffraction (XRD), atomic force microscopy and by investigating the mechanical properties, etc., with the aim of reducing cherry rain cracking. FTIR and XRD showed dual nanoparticles successfully implanted into CHC, CHC-PZNP-CNC combined moderate ductility (elongation at break: 7.8 %), maximum tensile strength (37.5 MPa). The addition of PZNP alone significantly improved wetting performance (Surface Tension, CHC: 55.3 vs. CHC-PZNP: 48.9 mN/m), while the addition of CNC alone led to a notable improvement in the water barrier properties of CHC (water vapor permeability, CHC: 6.75 × 10-10 vs. CHC-CNC: 5.76 × 10-10 gm-1 Pa-1 s-1). The final CHC-PZNP-CNC coating exhibited enhanced wettability (51.2 mN/m) and the strongest water-barrier property (5.32 × 10-10 gm-1 Pa-1 s-1), coupled with heightened surface hydrophobicity (water contact angle: 106.4°). Field testing demonstrated the efficacy of the CHC-PZNP-CNC coating in reducing cherry rain-cracking (Cracking Index, Control, 42.3 % vs. CHC-PZNP-CNC, 19.7 %; Cracking Ratio, Control, 34.6 % vs. CHC-PZNP-CNC, 15.8 %). The CHC-PZNP-CNC coating is a reliable option for preventing rain-induced cherry cracking.

The power of super-resolution microscopy in modern biomedical science.

Super-resolution microscopy (SRM) technology that breaks the diffraction limit has revolutionized the field of cell biology since its appearance, which enables researchers to visualize cellular structures with nanometric resolution, multiple colors and single-molecule sensitivity. With the flourishing development of hardware and the availability of novel fluorescent probes, the impact of SRM has already gone beyond cell biology and extended to nanomedicine, material science and nanotechnology, and remarkably boosted important breakthroughs in these fields. In this review, we will mainly highlight the power of SRM in modern biomedical science, discussing how these SRM techniques revolutionize the way we understand cell structures, biomaterials assembly and how assembled biomaterials interact with cellular organelles, and finally their promotion to the clinical pre-diagnosis. Moreover, we also provide an outlook on the current technical challenges and future improvement direction of SRM. We hope this review can provide useful information, inspire new ideas and propel the development both from the perspective of SRM techniques and from the perspective of SRM's applications.

Preparation of chitosan/citral forward osmosis membrane via Schiff base reaction with enhanced anti-bacterial properties.

In this study, hydrogels generated by the Schiff base reaction between citral and chitosan (CS) were used for the first time to improve the anti-bacterial property of forward osmosis (FO) membranes. The composite membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Water contact angle (WCA), Zeta potential and confocal laser scanning microscopic (CLSM). In the FO filtration experiment, the membrane performance of TFC-1 with 1 M sodium chloride solution as the draw solution and deionized water as the feed solution was the best, with the water flux of 25.54 ± 0.7 L m-2 h-1 and the reverse salt flux of 4.7 ± 0.4 g m-2 h-1. Although the hydrogel coating produced a certain hydraulic resistance, the flux of the modified membrane was only reduced by about 8%, compared with the unmodified membrane. However, the anti-bacterial property (Pseudomonas aeruginosa) and anti-fouling properties (bovine serum protein and lysozyme protein) of the modified membranes were improved, showing good antibacterial properties (99%) and flux recovery rate (over 90%). The modified method has the advantages of easy access to raw materials, simple operation and no risk of secondary pollution, which can effectively reduce the cost of chemical cleaning and extend the service life of the membrane. The modification of membrane by chitosan-based hydrogel is a promising option in the field of membrane anti-bacteria.

Synthesis of cellulose nanofiber/polysiloxane-polyurea composite materials with self-healing and reprocessing properties.

Inspired by the self-recoverability ability of organisms, various self-healing materials have been developed. However, most reinforced fillers are faced with the problem that mechanical strength and self-healing efficiency of materials cannot be improved simultaneously. Here we first prepared new polysiloxane-polyurea (PDMS-PU) and used it as matrix resin to prepare cellulose nanofiber (CNF)/PDMS-PU composite materials with high mechanical properties. CNFs increased the tensile strength of PDMS-PU by 38.87 % and CNF/PDMS-PU composite materials maintained the great bending resistance, transparency and reprocessing properties of PDMS-PU. Moreover, the introduction of CNFs did not reduce the self-healing efficiency of PDMS-PU, and PDMS-PU containing disulfide bonds with CNF content of 1 % (CNF/PDMS-IPDI-S-1 %) with healing efficiency of 95.58 %, and the tensile strength after three recycling processing was still as high as 92.55 % of the original. CNFs reinforced PDMS-PU composite materials are expected to replace PDMS materials in advanced engineering fields that require high strength durability and good formability.

Release characteristic of bound polyphenols from tea residues insoluble dietary fiber by mixed solid-state fermentation with cellulose degrading strains CZ-6 and CZ-7.

The purpose of this work was to investigate the release characteristic of bound polyphenols (BP) from tea residues insoluble dietary fiber (IDF) by mixed solid-state fermentation (SSF) with cellulose degrading strains CZ-6 and CZ-7. The results implied that cellulase, ß-glucosidase and filter paper lyase activities were strongly correlated with the BP content. The scanning electron microscop and fourier transform infrared spectroscopy manifested that the cellulose network of the IDF was decomposed and dissolve, forming more loose fibrous structure. Additionally, 28 polyphenols components were detected and their biotransformation pathways were preliminary speculated. Moreover, the BP obtained by mixed SSF produced prominent inhibitory activities against α-glucosidase and α-amylase, as well as exhibited significant scavenging effects on DPPH•, ABTS+• free radicals and ferric reducing antioxidant power. These findings could further promote the utilization of BP from agricultural by-products in a more natural and economical method, CZ-6 and CZ-7 strains provide a new approach to expound the release and conversion of BP.

Insights into the enhanced flux of graphene oxide composite membrane in direct contact membrane distillation: The different role at evaporation and condensation interfaces.

Graphene oxide (GO) coating has recently been reported as a novel approach to increase membrane flux of membrane distillation (MD), yet the phenomena underlying the process are still not fully understood. In this study, a mathematical model based on capillary-film assumption was developed and validated with the results (R2>0.99) from a series of MD experiments. According to the model, when GO layer was placed at the evaporation interface, the temperature difference across the membrane surface increases significantly (44.2%∼92.0%) and the temperature polarization coefficient is increased greatly from 0.29∼0.38 to around 0.55. This leads to a big increase of driving force for higher heat flow and subsequently mass flux (17.8∼45.5%). However, the vapor pressure on membrane surface was decreased due to Kelvin effect of GO capillary pores, which has a negative influence on the driving force, accounting for about 26.9% to 52.6% drop in the achieved flux. In comparison, when GO layer was placed at the condensation interface, the temperature difference across the membrane surface decreases slightly (7.2∼12.2%), but the reduced vapor pressure on GO capillary pores due to Kelvin effect become the dominant factor affecting membrane flux, resulting in an increase mass flux of 12.4∼16.4%. The model developed in this study provides a theoretical foundation for understanding the role of GO coating on flux improvement, and can be used for further development of high flux membranes.

Revealing the roles of polymers in supersaturation stabilization from the perspective of crystallization behaviors: A case of nimodipine.

Formulating drugs into amorphous solid dispersions (ASDs) represents an attractive means to enhance the aqueous solubility of drugs. Furthermore, water-soluble polymers have proven highly advantageous for stabilizing supersaturated solutions of ASDs. However, the performance and mechanism of various polymers in stabilizing supersaturated drug solutions have not been well-studied. The aim of this study was to investigate the effects of different commercial polymers on the dissolution behaviors and supersaturation stabilization of the ASDs and to further explore the mechanism of polymer mediated supersaturation maintenance by studying the crystallization behaviors of the ASDs. In this study, nimodipine (NMD) was used as a model drug because of its poor water-solubility and fast crystallization rate in aqueous solution, and three polymers polyvinylpyrrolidone (PVP), vinylpyrrolidone-vinyl acetate copolymer (PVP VA), and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer (Soluplus) was selected as the drug carriers to form the ASDs with NMD. Solid-state characterizations of the ASDs confirmed the amorphous state of the ASD systems. ASDPVP VA demonstrated superior supersaturation maintenance in dissolution experiments compared to the other two ASD systems. Among the polymers tested, PVP VA most efficiently maintained dissolution of NMD and prevented its crystallization from the supersaturated solution. The ability of PVP VA to most-effectively maintain supersaturation of the drug was manifested by inhibition of crystal nucleation rather than inhibition of crystal growth following nucleation. These results suggest that nucleation inhibition was instrumental in enabling the polymer-mediated supersaturation maintenance, at least with NMD.

Lignin-containing polyurethane elastomers with enhanced mechanical properties via hydrogen bond interactions.

In this work, lignin-containing polyester polyol (LPES) was successfully synthesized by vacuum melting method with lignin instead of polyol, and then reacted with isocyanate and chain extender to obtain lignin-based polyurethane elastomer (LPUE). The effects of lignin as reactive raw material, chain extender, and filler on the structure, thermostability, mechanical performance, and self-healing properties of elastomers were systematically studied, respectively. The comprehensive mechanical properties of the obtained materials were significantly enhanced after the introduction of lignin, especially the maximum tensile strength increased to 26.6 MPa and elongation at break reached 408.6%, which were 1510.3% and 2130.5% higher than that of the original polyurethane elastomer (PUE). Results revealed that lignin in the hard segment had a significant effect on the thermal stability and mechanical properties of polyurethane elastomer, and lignin in the soft segment had an obvious impact on the healing properties. Due to the hydrogen bonding interaction of the polar groups in the molecular chain of lignin to form a microphase-ordered structure, LPUE with excellent mechanical properties can be obtained.

Study on Microbial Community Succession and Functional Analysis during Biodegradation of Mushroom Residue.

In this study, 16S rRNA high-throughput sequencing technology was used to analyze the composition and diversity of bacterial and fungal communities in mushroom residue samples at different composting stages. During the composting process, the maximum temperature in the center of the pile can reach 52.4°C, and the temperature above 50°C has been maintained for about 8 days. The results showed that Actinobacteria, Firmicutes, Proteobacteria, Bacteroidetes, and Chloroflexi were the main microorganisms in the composting process, accounting for 98.9%-99.7% of the total bacteria. Furthermore, in order to obtain the protein expressed in each stage of composting, the nonstandard quantitative method (label free) was used to analyze it quantitatively by mass spectrometry, anda total of 22815 proteins were identified. It indicated that the number of identified proteins related to cellulose decomposition and the number of differentially expressed proteins were significantly enriched, and the functional proteins related to cellulose decomposition had significant stage correspondence.

Pt@polydopamine nanoparticles as nanozymes for enhanced photodynamic and photothermal therapy.

Polydopamine nanoparticles were used to stabilize a nano-Pt catalyst to relieve tumour hypoxia in photodynamic therapy (PDT). Polydopamine not only provides a platform for carrying nano-Pt and photosensitizers but is also used as a photothermal reagent for photothermal therapy (PTT). The system presented an enhanced anti-tumor therapy effect through a combined PDT and PTT mechanism.

Cell membrane covered polydopamine nanoparticles with two-photon absorption for precise photothermal therapy of cancer.

HYPOTHESIS: In view of the photothermal effect of polydopamine (PDA) nanoparticles and their internal D-π-D structures during assembly, the two-photon excited properties of PDA were studied toward the biomedical application. Further, the PDA molecules were coordinated with Mn2+ and the assembled nanoparticles were covered by cancer cell membranes, the complex system could be used directly for the treatment of cancer with photothermal and chemodynamic therapy. EXPERIMENTS: The two-photon excited PDA-Mn2+ nanoparticles were used for the photothermal therapy combined with chemodynamic therapy. The complexes were coated with cancer cell membranes in order to enhance the tumor homologous efficiency. Multi-modal bioimaging and anti-tumor detections were carried out both in vitro and in vivo. FINDINGS: PDA nanoparticles were demonstrated to have both good two-photon excited fluorescence and photothermal efficiency. The assembled nanoparticles modified with Mn2+ and cancer cell membranes have an obvious targeting and synergetic anti-cancer efficiency. The system creates a simple way for a precise operation with multi-modal imaging function.

Self-assembled supermolecular hydrogel based on hydroxyethyl cellulose: Formation, in vitro release and bacteriostasis application.

Self-assembly of cellulose-based hydrogel is a new supermolecular architecture with potential for biomedical applications. In this study, a novel cellulose-based, supermolecular self-assembled hydrogel (gel-(ß)CDP-HEC) was studied, which was based on the host-guest interaction between hydrophobic lauryl side chains grafting on hydroxyethyl cellulose (HECC12) and the cavities in poly(ß-cyclodextrin) (ß-CDP). The critical concentrations of HECC12 and ß-CDP should be both fixed at 30mgmL-1 by the results of dynamic viscosity, rheological property and swelling ratio. Fourier Transform Infrared Spectroscopy (FTIR), 1HNuclear Magnetic Resonance (1H NMR), Scanning Electron Microscope (SEM) and Gel Permeation Chromatography (GPC) studies were used to characterize the synthesized samples. Furthermore, the encapsulation capacity of gel-(ß)CDP-HEC was determined as 21.89wt% by phenolphthalein probe method. The loading and in vitro release of Eugenol (EG) were investigated. Thermogravimetric Analysis (TGA) was used to characterize the thermal stability of the EG-loaded gel-(ß)CDP-HEC (gel-(ß)CDP-HEC/EG). The bacteriostasis characteristics against Escherichia coli had been proved by agar cup-plate diffusion method. The results demonstrated that gel-(ß)CDP-HEC had a potential advantage as efficient bacteriostasis materials for biomedical applications.

Ultra-antireflective synthetic brochosomes.

Since the early discovery of the antireflection properties of insect compound eyes, new examples of natural antireflective coatings have been rare. Here, we report the fabrication and optical characterization of a biologically inspired antireflective surface that emulates the intricate surface architectures of leafhopper-produced brochosomes-soccer ball-like microscale granules with nanoscale indentations. Our method utilizes double-layer colloidal crystal templates in conjunction with site-specific electrochemical growth to create these structures, and is compatible with various materials including metals, metal oxides, and conductive polymers. These brochosome coatings (BCs) can be designed to exhibit strong omnidirectional antireflective performance of wavelengths from 250 to 2000 nm, comparable to the state-of-the-art antireflective coatings. Our results provide evidence for the use of brochosomes as a camouflage coating against predators of leafhoppers or their eggs. The discovery of the antireflective function of BCs may find applications in solar energy harvesting, imaging, and sensing devices.

An auxiliary gaze point estimation method based on facial normal.

Considering the main disadvantage of the existing gaze point estimation methods which restrict user's head movement and have potential injury on eyes, we propose a gaze point estimation method based on facial normal and binocular vision. Firstly, we calibrate stereo cameras to determine the extrinsic and intrinsic parameters of the cameras; Secondly, face is quickly detected by Viola-Jones framework and the center position of the two irises can be located based on integro-differential operators; The two nostrils and mouth are detected based on the saturation difference and their 2D coordinates can be calculated; Thirdly, the 3D coordinates of these five points are obtained by stereo matching and 3D reconstruction; After that, a plane fitting algorithm based on least squares is adopted to get the approximate facial plane, then, the normal via the midpoint of the two pupils can be figured out; Finally, the point-of-gaze can be obtained by getting the intersection point of the facial normal and the computer screen. Experimental results confirm the accuracy and robustness of the proposed method.