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Graphical abstract, We previously demonstrated that a marine bacterial pathogen Vibrio vulnificus isolated from sea foods modulated gene expression levels and defense responses of a land plant Arabidopsis thaliana. Although the interaction between V. vulnificus and A. thaliana was verified under artificial and greenhouse conditions, the simultaneous changes in host and pathogen transcriptomes remained obscure. In this study, we simultaneously analyzed the transcriptome of V. vulnificus MO6-24/O and A. thaliana by dual RNA-sequencing analysis. Disease symptoms appeared at 5 and 7 days post-inoculation in vitro and post-infiltration in planta, respectively. A total of 31, 128, 303, 219, and 130 differentially expressed genes (DEGs) were identified in V. vulnificus MO6-24/O at 3, 6, 12, 24, and 48 h post-infiltration. Out of these, 14 genes involved in the virulence and pathogenicity of V. vulnificus MO6 were characterized. These genes were clustered into six categories, including adherence, antiphagocytosis, chemotaxis and motility, iron uptake, toxin and secretion system. In plant side, the bacterium DEGs potentially played a pivotal role in activating pattern recognition receptors (PRRs)-mediated defense responses. A. thaliana genes related to PRRs, reactive oxygen species burst, mitogen-activated protein kinase cascade induction, salicylic acid, jasmonic acid, ethylene, abscisic acid, auxin, gibberellin, and cytokinin were highly induced by V. vulnificus MO6-24/O challenge. Taken together, our results indicate that the sophisticated communication between a marine bacterial pathogen V. vulnificus and A. thaliana occurs. It is the first report demonstration that V. vulnificus actively modulates its virulence factors and potential host immune regulator in a land plant species.

Crosslinking of polyolefin-based polymers can improve their thermal and mechanical properties, which can then be used in various applications. Radiation-induced crosslinking can be done easily and usefully by irradiation without a crosslinking agent. In addition, polymer blending can improve thermal and mechanical properties, and chemical resistance, compared to conventional single polymers. In this study, high-density polyethylene (HDPE)/ethylene vinyl acetate (EVA)/polyurethane (PU) blends were prepared by radiation crosslinking to improve the thermal and mechanical properties of HDPE. This is because HDPE, a polyolefin-based polymer, has the weaknesses of low thermal resistance and flexibility, even though it has good mechanical strength and machinability. In contrast, EVA has good flexibility and PU has excellent thermal properties and wear resistance. The morphology and mechanical properties (e.g., tensile and flexure strength) were characterized using scanning electron microscopy (SEM) and a universal testing machine (UTM). The gel fraction, thermal shrinkage, and abrasion resistance of samples were confirmed. In particular, after storing at 180 °C for 1 h, the crosslinked HDPE-PU-EVA blends exhibited ~4-times better thermal stability compared to non-crosslinked HDPE. When subjected to a radiation dose of 100 kGy, the strength of HDPE increased, but the elongation sharply decreased (80%). On the other hand, the strength of the HDPE-PU-EVA blends was very similar to that of HDPE, and the elongation was more than 3-times better (320%). Finally, the abrasion resistance of crosslinked HDPE-PU-EVA was ~9-times better than the crosslinked HDPE. Therefore, this technology can be applied to various polymer products requiring high heat resistance and flexibility, such as electric cables and industrial pipes.

Recent advancements in light-emitting diode technology provide an opportunity to evaluate the correlation between different light sources and plant growth as well as their secondary metabolites. The aim of this study was to determine the optimal light intensity and photoperiod for increasing plant growth and glucosinolate concentration and content in watercress. Two-week-old seedlings were transplanted in a semi-deep flow technique system of a plant factory for 28 days under four photoperiod–light intensity treatments (12 h—266 µmol·m−2·s−1, 16 h—200 µmol·m−2·s−1, 20 h—160 µmol·m−2·s−1, and 24 h—133 µmol·m−2·s−1) with the same daily light integral. The mean values of shoot fresh and dry weights were the highest under the 20 h—160 µmol·m−2·s−1 treatment, although there was no significant difference. Net photosynthesis and stomatal conductance gradually decreased with decreasing light intensity and increasing photoperiod. However, total glucosinolate concentration was significantly higher under 20 h—160 µmol·m−2·s−1 and 24 h—133 µmol·m−2·s−1 compared with 12 h—266 µmol·m−2·s−1 and 16 h—200 µmol·m−2·s−1. The total glucosinolate content was the greatest under 20 h—160 µmol·m−2·s−1 treatment. These data suggest that the 20 h—160 µmol·m−2·s−1 treatment promoted the maximum shoot biomass and glucosinolate content in watercress. This study supplies the optimal light strategies for the future industrial large-watercress cultivation.

The aim of this study was to determine the proper root pruning time and ratio for enhancing bioactive compound formation in Agastache rugosa without plant growth inhibition. The control (without root pruning) and five treatments (1, 3, 5, 7, and 9 days of root pruning before harvesting (RPBH)) with 50% root pruning (Experiment 1) and four treatments of root pruning ratios with 30, 50, 70, and 90% root length at 5 days RBPH (Experiment 2) were performed in a hydroponic culture system. The results showed that shoot fresh and dry weights did not differ significantly between the 1, 3, 7, and 9 days RPBH and the control. There were no significant differences in shoot fresh and dry weights between 30 and 50% root pruning ratios and the control. The soil–plant analysis development (SPAD) chlorophyll meter was significantly decreased under ratios of 70 and 90% and 1 and 3 days RPBH, compared to other treatments. The rosmarinic acid (RA) and tilianin concentrations of A. rugosa under 9 days RPBH with 50% root pruning were significantly (105% and 141%) higher than those of the control. The acacetin concentration under 7 days RPBH with 50% root pruning was significantly (316%) higher than that of the control, while the RA and acacetin concentrations under 30% root pruning at 5 days were significantly (108% and 251%) higher than that of the control. These results indicated that 50% root pruning at 7 or 9 days before harvesting increased the concentrations of acacetin, RA, and tilianin and 30% root pruning at 5 days before harvesting increased in the levels of acacetin and RA concentration in A. rugosa without plant growth inhibition.

The fruits, leaves, and roots of Cudrania tricuspidata have been reported to contain large amounts of vitamin B, vitamin C, and flavonoids. They exhibit various physiological activities su...

Despite their high theoretical energy density, lithium-oxygen (Li−O2) batteries suffer from limited cyclability originating from poor charging efficiency. In an effort to overcome this critical issue, a variety of catalysts have been introduced, but much room still remains for further advancement in catalyst design. By benchmarking hemoglobin in red blood cells that carry oxygen at a well-defined center of the molecular cage, herein, we report heme as an air-cathode catalyst with iron (Fe) active sites. Furthermore, the coordination of electron-withdrawing ligands, such as thiocyanate (S C N) and azide (N3), to the Fe center enhances its Lewis acidity to weaken the binding of oxygen intermediates (O2∗) towards more facile decomposition of the main discharging product (Li2O2). Density functional theory calculations and surface energy analysis of Fe coherently support the advantageous role of the ligand engineering in enhancing the reversibility of a Li−O2 battery.

In this study, we developed a smart drug delivery system that can efficiently deliver the required amounts of drugs using the excellent ion conductivity of poly(acrylic acid) (PAA) and an electrical stimulus. As a result of its having carboxyl groups, PAA hydrogel can be used in drug delivery patches to release drugs by ionic conductivity. However, PAA hydrogel has low durability and poor mechanical properties. The carboxyl group of PAA was combined with a siloxane group of silicone using electron-beam irradiation to easily form a crosslinked structure. The PAA–silicone hydrogel has excellent mechanical properties. Specifically, the tensile strength increased more than 3.5 times. In addition, we observed its cell compatibility using fluorescence staining and CCK-8 assays and found good cell viability. Finally, it was possible to control the drug delivery rate efficiently using the voltage applied to the ion-conductive hydrogel. As the voltage was increased to 3, 5, and 7 V, the amount of drug released was 53, 88, and 96%, respectively. These excellent properties of the PAA–silicone hydrogel can be used not only for whitening or anti-wrinkling cosmetics but also in medical drug-delivery systems.

Global climate change and the industrial revolution have increased the concentration of tropospheric ozone, a photochemical air pollutant that can negatively affect plant growth and crop production. In the present study, we investigated the effects of O3 on the metabolites and transcripts of tartary buckwheat. A total of 36 metabolites were identified by gas chromatography coupled with time-of-flight mass spectrometry, and principal component analysis was performed to verify the metabolic differences between nontreated and O3-treated tartary buckwheat. The content of threonic acid increased after 2 days of the O3 treatment, whereas it decreased after 4 days of exposure, after which it gradually increased until the eighth day of exposure. In addition, the levels of most metabolites decreased significantly after the O3 treatment. On the contrary, the levels of two anthocyanins, cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside, increased more than 11.36- and 11.43-fold, respectively, after the O3 treatment. To assess the effect of O3 on the genomic level, we analyzed the expression of anthocyanin biosynthesis pathway genes in O3-treated and nontreated buckwheat using quantitative real-time reverse transcription polymerase chain reaction (PCR). We found that the expression of all anthocyanin pathway genes increased significantly in the O3-treated buckwheat compared to that in the nontreated buckwheat. Altogether, our results suggested that O3 affected the transcripts and metabolites of tartary buckwheat, which would eventually cause phenotypic changes in plants.

Bioelectrodes, including metallic and conductive polymer (CP) bioelectrodes, often suffer from biofouling by contamination from microbacteria and/or biomolecules in biological systems, which can cause substantial impairment of biofunctionality and biocompatibility. Herein, we have employed an in situ polymerization of methacryloyloxyethyl phosphorylcholine (MPC) by gamma radiation to introduce fouling-resistant properties onto the surface of the conductive polymer, polypyrrole (PPy). The concentrations of an MPC monomer were varied during the grafting. PPy electrodes modified with MPC (PPy-g-MPC) revealed excellent anti-biofouling properties, as demonstrated by multiple analyses, such as serum protein adsorption, fibroblast adhesion, bacteria adhesion, and scar tissue formation in vivo. Importantly, PPy-g-MPC, which was modified with 0.2 M MPC using gamma radiation, exhibited electrical properties similar to unmodified PPy electrodes, indicating that our MPC grafting strategies did not cause impairment of electrical/electrochemical properties of the original PPy electrodes while successfully introducing anti-biofouling properties. Zwitterionic MPC polymer grafting on PPy electrodes by in situ polymerization with gamma radiation will benefit the development of highly biocompatible and functional bioelectrodes, such as neural electrodes, stimulators, and biosensors.

Agsatache rugosa (Korean mint), belongs to the mint family and it has various medicinal properties. In addition, it has several valuable compounds such as monoterpenes and phenylpropanoid compounds. Amongst these, two compounds viz., rosmarinic acid (RA), and tilianin are well-known natural compounds that have numerous pharmacological properties. The phenylpropanoid biosynthetic gene expression under stress conditions and the subsequent accumulation of phenylpropanoid content has not been extensively studied in Korean mint. Here, we investigated the effect of light-emitting diodes (LEDs) on the expression levels of phenylpropanoid biosynthetic pathway genes and the accumulation of phenylpropanoid compounds such as RA and tilianin in A. rugosa. Real-time PCR analysis showed that the phenylpropanoid pathway genes responded to the LED lights. The transcript levels of downstream genes (C4H, CHS, CHI, and RAS) were comparatively higher than those of upstream genes (PAL, TAT, and HPPR). In addition, HPLC analysis showed that the content of RA and tilianin were significantly higher in plants cultivated under white light than those grown under red, blue, green, and orange lights. The RA and tilianin content were the highest in the plantlets after three weeks of exposure to white light. These results suggested that white LED lights significantly enhanced the accumulation of phenylpropanoid compounds in A. rugosa.

Plants respond to root temperature stresses by producing antioxidants as a defense mechanism. Since a number of these are phytochemicals with enhancing effects on human health, we examined the effects of 4 root-zone temperature (RZT) treatments (10, 20, 28, and 36 &deg, C) on plant growth and the main bioactive compound concentrations in each organ of Agastache rugosa plants. We aimed to determine the optimal RZT treatment to increase bioactive compound concentrations with no deleterious effects on plant growth. Four-week-old seedlings were grown in a plant factory for 32 days. Nine plant growth parameters, namely, shoot and root fresh weights, stem and root lengths, leaf length and leaf width, leaf area, and shoot and root dry weights were significantly decreased at 10 and 36 &deg, C compared with other treatments. A similar pattern was observed for the chlorophyll content and leaf gas exchange parameters. Of all the RZT treatments, RZT at 28 &deg, C produced the significantly greatest accumulation of two major bioactive compounds, namely, rosmarinic acid (RA) and tilianin contents per the A. rugosa plant, and had no adverse effects on the overall growth of A. rugosa. This supports the use of 28 &deg, C RZT to successfully improve the bioactive compounds with no adverse influence on plant growth or yield.

The objective of this study was to determine the proper electrical conductivity (EC) of a nutrient solution (NS) for accumulating bioactive compounds of Agastache rugosa without decreasing plant growth. Six-week-old seedlings were transplanted in a deep flow technique system with Hoagland NS with a 2.0 dS&middot, m&minus, 1 EC for the initial week. From eight days after transplanting, the plants were treated with six EC treatments of 0.5, 1.0, 2.0, 4.0, 6.0, and 8.0 dS&middot, 1 for three weeks. Plant growth parameters, leaf gas exchange parameters, the relative chlorophyll value, and the ratio of variable to maximum fluorescence (Fv/Fm) were measured, and the rosmarinic acid (RA), tilianin, and acacetin concentrations were analyzed at 28 days after transplanting. The results showed that almost all plant growth parameters were maximized at 2.0 and 4.0 dS&middot, 1 and minimized at 8.0 dS&middot, 1 compared with the other EC treatments. The relative chlorophyll and Fv/Fm values were maximized at 2.0 and 4.0 dS&middot, 1. Similarly, leaf gas exchange parameters were increased at 2.0 and 4.0 dS&middot, 1. The RA content exhibited significantly higher values at 0.5, 1.0, 2.0, and 4.0 dS&middot, 1 compared with other treatments. The tilianin and acacetin contents exhibited the significantly highest values at 4.0 and 0.5 dS&middot, 1, respectively. These results suggest optimal EC treatment at 4.0 dS&middot, 1 for increasing bioactive compounds in A. rugosa plants without decreasing plant growth. Excessively high or low EC induced salinity stress or nutrient deficiency, respectively. Furthermore, among the plant organs, the roots of A. rugosa contained the highest RA concentration and the flowers contained the highest tilianin and acacetin concentrations, which revealed a higher utilization potential of the roots and flowers for bioactive compounds.

Salinity stress affects plants by reducing the water potential and causing ion imbalance or disturbances in ion homeostasis and toxicity. Salinity stress frequently causes both osmotic and ionic stress in plants, resulting in the increase or decrease of certain secondary metabolites in plants. In this study, the effect of NaCl treatment on the nutritional quality of tartary buckwheat plants was studied by conducting an HPLC analysis of phenylpropanoid and anthocyanin content. It was observed that there was no significant change of color in tartary buckwheat during salt treatment. The accumulation of most phenylpropanoid compounds increased slightly in response to the NaCl concentration. The total phenylpropanoid content in tartary buckwheat was the highest at 100 mM NaCl treatment. Seven-day-old wheat plantlets treated with 100 mM NaCl for 2, 4, 6, and 8 days showed the highest accumulation of total phenylpropanoids at day 8 after treatment, while the content of most phenylpropanoids was higher than that in the control during this period. Although the development of tartary buckwheat slightly decreased with NaCl treatment and the accumulation of anthocyanin compounds did not change in plants with a diffident NaCl concentration and time treatment, the results suggest that the salinity treatment of tartary buckwheat causes antioxidant activity improvement by inducing an accumulation of flavonoid and phenolic compounds. However, since the anthocyanin content did not increase, the antioxidant effect of the treatment is not expected to be significant.

Sung In Jeong,1,* Seong-Cheol Park,2,* Sun-Jeong Park,2,* Eun-Ji Kim,2 Hun Heo,2 Jong-Seok Park,1 Hui-Jeong Gwon,1 Youn-Mook Lim,1 Mi-Kyeong Jang2 1Research Division for Industry and Environment, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup, 2Department of Polymer Science and Engineering, College of Engineering, Sunchon National University, Suncheon, Korea *These authors contributed equally to this work Introduction: Although numerous studies have been conducted with the aim of developing drug-delivery systems, chemically synthesized gene carriers have shown limited applications in the biomedical fields due to several problems, such as low-grafting yields, undesirable reactions, difficulties in controlling the reactions, and high-cost production owing to multi-step manufacturing processes. Materials and methods: We developed a 1-step synthesis process to produce 2-aminoethyl methacrylate-grafted water-soluble chitosan (AEMA-g-WSC) as a gene carrier, using gamma irradiation for simultaneous synthesis and sterilization, but no catalysts or photoinitiators. We analyzed the AEMA graft site on WSC using 2-dimensional nuclear magnetic resonance spectroscopy (2D NMR; 1H and 13C NMR), and assayed gene transfection effects in vitro and in vivo. Results: We revealed selective grafting of AEMA onto C6-OH groups of WSC. AEMA-g-WSC effectively condensed plasmid DNA to form polyplexes in the size range of 170 to 282 nm. AEMA-g-WSC polyplexes in combination with psi-hBCL2 (a vector expressing short hairpin RNA against BCL2 mRNA) inhibited tumor cell proliferation and tumor growth in vitro and in vivo, respectively, by inducing apoptosis. Conclusion: The simple grafting process mediated via gamma irradiation is a promising method for synthesizing gene carriers. Keywords: water-soluble chitosan, 2-aminoethyl methacrylate, gamma irradiation, gene delivery

Agastache rugosa, is a perennial medicinal plant commonly used in Chinese herbalism, and may have anti-atherogenic and antibacterial properties. Here in this study, we investigated the growth and variations in antioxidant contents of A. rugosa in response to nutrient solution and photosynthetic photon flux density (PPFD) with artificial lighting for a hydroponics culture. Fluorescent light at 150, and 200 μmol·m-2·s-1 PPFD with a 16/8 (light/dark) photoperiod, combined with four different nutrient solutions [developed by Horticulture experiment station in Japan (HES), University of Seoul (UOS), Europe vegetable research center (EVR), Otsuka-house 1A (OTS)], were used in a hydroponics culture system for 6 weeks. The shoot and root dry weights of A. rugosa grown with the OTS were significantly higher than those of other nutrient solutions. The amount of tilianin was the highest grown with the OTS, followed by EVR, HES, and UOS. Total acacetin content was the highest in A. rugosa grown under EVR which was statistically similar with OTS. The A. rugosa grown under 200 μmol·m-2·s-1 PPFD produced higher fresh weight and both acacetin and tilianin contents than that grown under 150 μmol·m-2·s-1 PPFD. The present results suggested that OTS along with 200 μmol·m-2·s-1 PPFD could be an optimum growing condition for better growth and higher accumulation of tilianin and acacetin contents in A. rugosa with hydroponic culture systems in a plant factory.

Although micro-porous membranes made of polyethylene (PE) offer excellent mechanical strength and chemical stability, they exhibit large thermal shrinkage at high temperature, which causes a short circuit between positive and negative electrodes in cases of unusual heat generation. We tried to develop a new technology to reduce the thermal shrinkage of PE separators by introducing γ -Al 2 O 3 particles treated with coupling agent on PE separators. Nanocomposite γ -Al 2 O 3 /PE separators were prepared by the dip coating of polyethylene(PE) separators in γ -Al 2 O 3 /poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP)/crosslinker (1,3,5-trially-1,3,5-triazine-2,4,6(1 H,3 H,5 H)-trione (TTT) solution with humidity control followed by electron beam irradiation. γ -Al 2 O 3 /PVDF-HFP/TTT (95/5/2)-coated PE separator showed the highest electrolyte uptake (157%) and ionic conductivity (1.3 mS/cm). On the basis of the thermal shrinkage test, the nanocomposite γ -Al 2 O 3 /PE separators containing TTT irradiated by electron beam exhibited a higher thermal resistance. Moreover, a linear sweep voltammetry test showed that the irradiated nanocomposite γ -Al 2 O 3 /PE separators have electrochemical stabilities of up to 5.0 V. In a battery performance test, the coin cell assembled with γ -Al 2 O 3 /PVDF-HFP/TTT-coated PE separator showed excellent discharge cycle performance.

Polycaprolactone (PCL) has been considered a useful material for orthopedic devices and osseous implants because of its biocompatibility and bone-forming activity. However, PCL-based scaffolds have hydrophobic surfaces that reduce initial cell viability. In this study, we fabricated surface-modified PCL nanofibers for tissue engineering using radiation technology. We supplemented the hydrophilicity of the PCL nanofibers by introducing 2-aminoethyl methacrylate (AEMA) through gamma-irradiation and subsequently immobilized heparin onto the nanofibers using the EDC/NHS reaction. The SEM images show that there is almost no change in the morphology of nanofibers after radiation grafting of AEMA and heparin-immobilization onto PCL nanofibers. The surface properties of the scaffolds were characterized by ATR-FTIR, XPS, and fluorescamine staining in order to confirm the successful grafting of AEMA onto the PCL nanofibers. Immobilization of heparin was also confirmed by the amide I (1650 cm(-1)) and amide II group (1550 cm(-1)) from ATR-FTIR. The amounts of heparin were drastically increased on the AEMA-PCL nanofibers as revealed by TBO assay. The initial cell viability of hMSCs was significantly increased on the AEMA grafted nanofibers but grew slowly on heparin-immobilized nanofibers. The cumulative release of bone morphogenetic protein-2 (BMP-2) was slow and continuous onto the heparin-immobilized nanofibers (18.13 +/- 3.87 mu g mL(-1)) compared to PCL nanofibers (20.25 +/- 1.45 mu g mL(-1)). Therefore, heparin-immobilized nanofibers may be a good tool for tissue engineering applications using radiation technology.

Traditionally, Agastache rugosa (Korean mint) has been widely used to treat various infectious diseases. The aims of this study were to: (i) determine the phenylpropanoid content of the plant using high-performance liquid chromatography, (ii) undertake total anthocyanin, flavonoid, and phenolic assays, (iii) and evaluate the antioxidant and antibacterial properties of the methanol extracts from the stem, leaves, and flowers of Korean mint. The total anthocyanin, flavonoid, and phenolic content assays showed that the flowers had higher phenolic levels than the stem and leaves. The reducing power, the 2,2-diphenyl-1-picrylhydrazyl superoxide radical scavenging abilities, and the hydrogen peroxide radical scavenging activities were also evaluated so that the antioxidant activities of the extracts from the different plant parts could be evaluated. The flower extracts revealed higher antioxidant properties than the other parts. The antibacterial properties of the methanol extracts from A. rugosa were analyzed by the disc diffusion method, and the flower extracts had higher antibacterial activities against the six bacterial strains used in the study than the other parts. This study provides information on the synergistic antioxidant and antibacterial properties of phenolics derived from the different parts of Korean mint.

This study aimed to determine the optimal indole-3-acetic acid (IAA) concentration in a nutrient solution to increase the bioactive compounds while enhancing the plant growth of A. rugosa grown hydroponically. Twenty-eight-day-old plants were transplanted in a plant factory for 32 days. The plants were subjected to various IAA concentrations (10&minus, 11, 10&minus, 9, 10&minus, 7, and 10&minus, 5 M) from 8 days after transplanting, and the control treatment (without IAA). Shoot and root fresh weights were effectively improved under 10&minus, 7 and 10&minus, 9 IAA treatments. Leaf gas exchange parameters were increased under 10&minus, 9 IAA treatments. Four of the IAA treatments, except 10&minus, 11 IAA treatment, significantly increased the rosmarinic acid (RA) concentration, as well as the tilianin concentration was significantly increased at all IAA treatments, compared with that of the control. Especially, the tilianin concentration of the 10&minus, 11 IAA treatment was significantly (1.8 times) higher than that of the control. The IAA treatments at 10&minus, 5 and 10&minus, 7 significantly raised the acacetin concentrations (1.6- and 1.7-times, respectively) compared to those of the control. These results suggested that 10&minus, 7 concentration of IAA in a nutrient solution was effective for enhancing plant growth and increasing bioactive compounds in A. rugosa, which offers an effective strategy for increasing phytochemical production in a plant factory.

Conducting polymer (CP)-based hydrogels exhibit the behaviors of bending or contraction/relaxation due to electrical stimulation. They are similar in some ways to biological organs and have advantages regarding manipulation and miniaturization. Thus, these hydrogels have attracted considerable interest for biomedical applications. In this study, we prepared PPy/PVP hydrogel with different concentrations and content through polymerization and cross-linking induced by gamma-ray irradiation at 25 kGy to optimize the mechanical properties of the resulting PPy/PVP hydrogel. Optimization of the PPy/PVP hydrogel was confirmed by characterization using scanning electron microscopy, gel fraction, swelling ratio, and Fourier transform infrared spectroscopy. In addition, we assessed live-cell viability using live/dead assay and CCK-8 assay, and found good cell viability regardless of the concentration and content of Py/pTS. The conductivity of PPy/PVP hydrogel was at least 13 mS/cm. The mechanical properties of PPy/PVP hydrogel are important factors in their application for biomaterials. It was found that 0.15PPy/PVP20 (51.96 &plusmn, 6.12 kPa) exhibited better compressive strength than the other samples for use in CP-based hydrogels. Therefore, it was concluded that gamma rays can be used to optimize PPy/PVP hydrogel and that biomedical applications of CP-based hydrogels will be possible.

A graphene sulfide framework (GSF) is designed and synthesized via a hybridization of graphene and organic compounds for use in electrodes for high-performance Li-ion batteries (LIB). This electrode material is devoid of transition metal and features a layered framework structure that is constructed by the formation of covalent disulfide bonds between organic linker molecules and graphene sheets. This structure capitalizes on the advantageous properties of each of the components in an electrochemical reaction. The structures of GSFs are characterized by Cs-corrected transmission electron microscopy (Cs-TEM), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). Depending on current density, the GSF electrodes exhibit two different types of electrochemical behavior during Li incorporation/extraction process, indicating the involvement of multiple Li-incorporation mechanisms. Various types of dithiol organics as linker components are incorporated in the GSF to evaluate the effect of length or structure on the electrochemical properties. The linker-dependent Li storage mechanism is explained based on the results of differential capacity analyses and electrochemical impedance spectroscopy (EIS). The GSF proposed in this study shows promise as an electrode material for a high-performance energy-storage system that is inexpensive and free of transition metals.

Here, accumulation of glucosinolates and expression of glucosinolates biosynthesis genes in green and red mustard hairy roots were identified and quantified by HPLC and qRT-PCR analyses. The total glucosinolates content of green mustard hairy root (10.09 µg/g dry weight) was 3.88 times higher than that of red mustard hairy root. Indolic glucosinolates (glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin) in green mustard were found at 30.92, 6.95, and 5.29 times higher than in red mustard hairy root, respectively. Conversely, levels of glucotropaeolin (aromatic glucosinolate) was significantly higher in red mustard than in green mustard. Accumulation of glucoraphasatin, an aliphatic glucosinolate, was only observed only in red mustard hairy roots. Quantitative real-time PCR analysis showed that the expression level of genes related to aliphatic and aromatic glucosinolate biosynthesis were higher in red mustard, exception BjCYP83B. The expression of BjCYP79B2, which encodes a key enzyme involved in the indolic glucosinolate biosynthetic pathway, was higher in green mustard than in red mustard. Additionally, to further distinguish between green mustard and red mustard hairy roots, hydrophilic and lipophilic compounds were identified by gas chromatography-mass spectrometry and subjected to principal component analysis. The results indicated that core primary metabolites and glucosinolate levels were higher in the hairy roots of green mustard than in those of red mustard.

Phenylpropanoids and flavonoids belong to a large group of secondary metabolites, and are considered to have antioxidant activity, which protects the cells against biotic and abiotic stresses. However, the accumulation of phenylpropanoids and flavonoids in bitter melon has rarely been studied. Here, we identify ten putative phenylpropanoid and flavonoid biosynthetic genes in bitter melon. Most genes were highly expressed in leaves and/or flowers. HPLC analysis showed that rutin and epicatechin were the most abundant compounds in bitter melon. Rutin content was the highest in leaves, whereas epicatechin was highly accumulated in flowers and fruits. The accumulation patterns of trans-cinnamic acid, p-coumaric acid, ferulic acid, kaempferol, and rutin coincide with the expression patterns of McPAL, McC4H, McCOMT, McFLS, and Mc3GT, respectively, suggesting that these genes play important roles in phenylpropanoid and flavonoid biosynthesis in bitter melon. In addition, we also investigated the optimum light conditions for enhancing phenylpropanoid and flavonoid biosynthesis and found that blue light was the most effective wavelength for enhanced accumulation of phenylpropanoids and flavonoids in bitter melon.

Poly(acrylic acid) (PAAc) hydrogels possess good bioadhesive properties and allow enhanced penetration of drugs. In addition, it is possible to localize the absorption site of the drug in the hydrogel and increase the drug residence time. As opposed to other cross-linking processes radiation-induced polymer cross-linking can be easily and rapidly carried out without the use of cross-linking agents and other chemical additives. In this study, we fabricated metronidazole (MD) containing PAAc hydrogel (MD/PAAc) with different MD contents (0.1, 0.25, 0.5 wt%) using varying radiation doses (25, 50, 75 kGy) by gamma-irradiation. The physical and thermal properties were determined by gel content analysis, swelling ratio measurements, compressive strength measurements, differential scanning calorimetery, and thermogravimetric analysis. The properties of the hydrogel degraded due to the crystalline nature of MD. The properties of the hydrogel degraded due to the crystalline nature of MD. Cumulative release observed after 50 min in the case of 0.5MD/PAAc and 0.1MD/PAAc was 50% and 10%, respectively. Our findings suggest that MD/PAAc could be a suitable drug delivery carrier for use with radiation-based techniques.

Conductive polymers, including polypyrrole (PPy), have been extensively explored to fabricate electrically conductive biomaterials for bioelectrodes and tissue engineering scaffolds. For their in vivo uses, a sterilization method without severe impairment of original material properties and performance is necessary. Gamma-ray radiation has been commonly applied for sterilization of medical products because of its simple and uniform sterilization without heat generation. Herein we describe the first study on gamma-ray sterilization of PPy bioelectrodes and its effects on their characteristics. We irradiated PPy bioelectrodes with different doses (0–75 kGy) of gamma-rays. Gamma-ray irradiation of the PPy (γ-PPy) increased the oxygenation and hydrophilicity of the surfaces. Interestingly, gamma-ray irradiation did not alter the electrical impedances and conductivities of the PPy substrates. Additionally, γ-PPy prepared with various dopants (e.g., para-toluene sulfonate, polystyrene sulfonate, and chlorine) showed the electrochemical properties similar to the non-irradiated control. Gamma-ray irradiation at doses of ≥15 kGy was required for effective sterilization as evidenced by complete eradication of gram positive and negative bacteria. γ-PPy substrates also showed cytocompatibility similar to untreated control PPy, indicating no substantial alteration of cytocompatibility. In conclusion, gamma ray sterilization is a viable method of sterilization of conducting polymer-based biomaterials for biomedical applications.

Bacterial cellulose (BC) is an excellent biomaterial with many medical applications. In this study, resorbable BC membranes were prepared for guided bone regeneration (GBR) using an irradiation technique for applications in the dental field. Electron beam irradiation (EI) increases biodegradation by severing the glucose bonds of BC. BC membranes irradiated at 100 kGy or 300 kGy were used to determine optimal electron beam doses. Electron beam irradiated BC membranes (EI-BCMs) were evaluated by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, thermal gravimetric analysis (TGA), and using wet tensile strength measurements. In addition, in vitro cell studies were conducted in order to confirm the cytocompatibility of EI-BCMs. Cell viabilities of NIH3T3 cells on 100k and 300k EI-BCMs (100 kGy and 300 kGy irradiated BC membranes) were significantly greater than on NI-BCMs after 3 and 7 days (p < 0.05). Bone regeneration by EI-BCMs and their biodegradabilities were also evaluated using in vivo rat calvarial defect models for 4 and 8 weeks. Histometric results showed 100k EI-BCMs exhibited significantly larger new bone area (NBA; %) than 300k EI-BCMs at 8 weeks after implantation (p < 0.05). Mechanical, chemical, and biological analyses showed EI-BCMs effectively interacted with cells and promoted bone regeneration.

Bacterial cellulose (BC) has been shown to have a high-burst pressure, high-water contact, and ultrafine highly nanofibrous structure similar with that in a natural extracellular matrix (ECM). In the present study, we developed a BC-based functional scaffold for tissue engineering using radiation technology. BC was generated by Gluconacetobacter hansenii TL-2C. Acrylic acid (AAc) was grafted onto BC surfaces under aqueous conditions using gamma-ray irradiation. The characterization of the scaffold was performed by scanning electron microscopy, ATR-FTIR spectroscopy, a toluidine blue O assay, and 2,4,6,-trinitro-benzensulfonic acid assay. AAc was grafted on the BC under gamma-ray irradiation. Gelatin was chemically conjugated on the AAc-BC scaffolds through EDC chemistry. The morphology of the modified BC nanofibers did not change, while representative features of AAc and gelatin were maintained. The adhesion and spreading of human mesenchymal stem cells was improved on the gelatin-AAc-BC nanofibers compared to unmodified BC and AAc-BC nanofibers. Our results suggest that gelatin-immobilized BC nanofiber scaffolds can be a promising way to fabricate three-dimentional, nanofibrous scaffolds that accelerate cell behavior for biomedical applications.

The goal of this study was to develop a novel hydroxyapatite (HA) coated bacterial cellulose (BC) scaffold for bone tissue regeneration. HA-coated BC was prepared by immersing in 30 mL of 5× simulated body fluid at 37°C for 12 h. The resulting HA-coated BC scaffolds were characterized by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared (ATRFTIR) spectroscopy, and thermal gravimetric analysis (TGA). HA spherical globules were newly formed on the surface of the BC, and a fibrous network of BC scaffolds still maintained their dimensions for cell adhesion and proliferation. ATR-FTIR spectroscopy analysis showed bands assigned to specific signals for phosphate and carbonate ions from HA. HA-coated BC scaffolds of thermal gravimetric analysis presented residue of around 25%. The ability for bone regeneration of HA-coated BC scaffolds was evaluated using a rat calvarial defect model for 4 and 8 weeks. After implantation, both BC and HAcoated BC scaffolds showed new bone formation derived from existing bone, and found new bone even inside the scaffold. Furthermore, a new bone area was signigicantly increased in the HA-coated BC scaffolds compared with those from BC scaffolds, and bone-like materials were frequently found in HA-coated BC scaffolds. Therefore, the HA-coated BC scaffolds can be used as an effective tool for bone tissue regeneration.

This study investigated optimum light conditions for enhancing phenylpropanoid biosynthesis and the distribution of phenylpropanoids in organs of Chinese cabbage (Brassica rapa ssp. pekinensis). Blue light caused a high accumulation of most phenolic compounds, including p-hydroxybenzoic acid, ferulic acid, quercetin, and kaempferol, at 12 days after irradiation (DAI). This increase was coincident with a noticeable increase in expression levels of BrF3H, BrF3'H, BrFLS, and BrDFR. Red light led to the highest ferulic acid content at 12 DAI and to elevated expression of the corresponding genes during the early stages of irradiation. White light induced the highest accumulation of kaempferol and increased expression of BrPAL and BrDFR at 9 DAI. The phenylpropanoid content analysis in different organs revealed organ-specific accumulation of p-hydroxybenzoic acid, quercetin, and kaempferol. These results demonstrate that blue light is effective at increasing phenylpropanoid biosynthesis in Chinese cabbage, with leaves and flowers representing the most suitable organs for the production of specific phenylpropanoids.

In this work, we present a biomimetic fibrous scaffold containing two biomolecules. A biocompatible poly(L-lactide-co-e-caprolactone) mesh was fabricated by an electrospinning method, and then acrylic acid was grafted on the mesh to introduce a carboxyl group through γ-ray irradiation. Subsequently, the epidermal growth factor (EGF) and gelatin were coupled to the mesh through the EDC reaction. The modified mesh presents a consistent fibre diameter (874.4 ± 178.5 nm), with carboxyl groups (1.3 mM). EGF (171.7 ng mg−1 mesh) and gelatin (67.2 ± 30.5 μg mg−1 mesh) were successfully coupled on the mesh. The coupled EGF and gelatin promoted the cell viability 1.5-times higher than that from a non-modified mesh. In particular, the EGF on the meshes independently allowed hMSC to present a 3-times greater involucrin expression and enabled improved procollagen secretion, implying trans-differentiation of hMSC to keratinocyte-like cells. Therefore, the co-immobilization strategy of biomolecules using radiation technology may be an alternative tool for tissue engineering applications.

A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

This study explored a novel strategy to restore the vocal gap by using cross-linkedβ-glucan hydrogel byγ-irradiation. An aqueous solution of 5 wt%β-glucan was prepared and cross-linked using60Coγirradiation. Ten nude mice were injected with 0.8 mL of irradiatedβ-glucan on the left back and the same volume of nonirradiatedβ-glucan on the right back for comparison. The mice were sacrificed at 1 and 2 weeks after injection and histological evaluations were performed. Irradiatedβ-glucan demonstrated a significantly larger volume than nonirradiatedβ-glucan in the back of nude mice with less inflammatory reaction. After unilateral recurrent laryngeal nerve section in New Zealand White rabbits, irradiated and nonirradiatedβ-glucan were injected into paralyzed vocal folds. Irradiatedβ-glucan remained at the paralyzed vocal fold without definite inflammatory signs on endoscopy. High-speed recordings of vocal fold vibration showed decreased vocal gap in irradiated group compared to nonirradiated group. Histologically, the laryngeal epithelium and lamina propria remained intact, without inflammatory cell infiltration. Our newly developed injection material, irradiatedβ-glucan, showed excellent biocompatibility and remained longer than nonirradiatedβ-glucanin vivo, suggesting irradiated hydrogels as a new therapeutic approach that may be useful for the long-term treatment of vocal fold palsy.

Background Watercress (Nasturtium officinale R. Br.) is an aquatic herb species that is a rich source of secondary metabolites such as glucosinolates. Among these glucosinolates, watercress contains high amounts of gluconasturtiin (2-phenethyl glucosinolate) and its hydrolysis product, 2-phennethyl isothiocyanate, which plays a role in suppressing tumor growth. However, the use of N. officinale as a source of herbal medicines is currently limited due to insufficient genomic and physiological information. Results To acquire precise information on glucosinolate biosynthesis in N. officinale, we performed a comprehensive analysis of the transcriptome and metabolome of different organs of N. officinale. Transcriptome analysis of N. officinale seedlings yielded 69,570,892 raw reads. These reads were assembled into 69,635 transcripts, 64,876 of which were annotated to transcripts in public databases. On the basis of the functional annotation of N. officinale, we identified 33 candidate genes encoding enzymes related to glucosinolate biosynthetic pathways and analyzed the expression of these genes in the leaves, stems, roots, flowers, and seeds of N. officinale. The expression of NoMYB28 and NoMYB29, the main regulators of aliphatic glucosinolate biosynthesis, was highest in the stems, whereas the key regulators of indolic glucosinolate biosynthesis, such as NoDof1.1, NoMYB34, NoMYB51, and NoMYB122, were strongly expressed in the roots. Most glucosinolate biosynthetic genes were highly expressed in the flowers. HPLC analysis enabled us to detect eight glucosinolates in the different organs of N. officinale. Among these glucosinolates, the level of gluconasturtiin was considerably higher than any other glucosinolate in individual organs, and the amount of total glucosinolates was highest in the flower. Conclusions This study has enhanced our understanding of functional genomics of N. officinale, including the glucosinolate biosynthetic pathways of this plant. Ultimately, our data will be helpful for further research on watercress bio-engineering and better strategies for exploiting its anti-carcinogenic properties. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3792-5) contains supplementary material, which is available to authorized users.

This study introduces the effect of the thickness of a bacterial cellulose membrane by comparing the bone regeneration effect on rat skulls when using a collagen membrane and different thicknesses of resorbable bacterial cellulose membranes for guided bone regeneration. Barrier membranes of 0.10 mm, 0.15 mm, and 0.20 mm in thickness were made using bacterial cellulose produced as microbial fermentation metabolites. Mechanical strength was investigated, and new bone formation was evaluated through animal experimental studies. Experimental animals were sacrificed after having 2 weeks and 8 weeks of recovery, and specimens were processed for histologic and histomorphometric analyses measuring the area of bone regeneration (%) using an image analysis program. In 2 weeks, bone-like materials and fibrous connective tissues were observed in histologic analysis. In 8 weeks, all experimental groups showed the arrangement of osteoblasts surrounding the supporting body on the margin and center of the bone defect region. However, the amount of new bone formation was significantly higher (p < 0.05) in bacterial cellulose membrane with 0.10 mm in thickness compared to the other experimental groups. Within the limitations of this study, a bacterial cellulose membrane with 0.10 mm thickness induced the most effective bone regeneration.

Ethnopharmacological relevance Many studies have emphasized that flavonoids, found in various fruits, vegetables, and seeds, as well as tea and red wine, have potential health-promoting and disease-preventing effects. Rhamnetin is a flavonoid that exhibits antioxidant capabilities. However, little is known about its effect on cardiac myocytes under oxidative stress and the underlying mechanisms. Materials and methods H9c2 cardiomyoblast cells were subjected to H 2 O 2 , to study the protective effect of rhamnetin on cell viability, apoptosis, and ROS production. Signaling proteins related to apoptosis, survival, and redox were analyzed by Western blot. Furthermore, the mRNA expressions of SIRTs were tested by real time-polymerase chain reaction (PCR). Results We investigated the protective effects of rhamnetin against H 2 O 2 -induced apoptosis in H9c2 cardiomyoblasts. Rhamnetin protected cells against H 2 O 2 -induced cell death without any cytotoxicity, as determined by the XTT assay, LDH assay, TUNEL assay, Hoechst 33342 assay, and Western blot analysis of apoptosis-related proteins. Rhamnetin also enhanced the expression of catalase and Mn-SOD, thereby inhibiting production of intracellular ROS. Furthermore, rhamnetin recovered the H 2 O 2 -induced decrease in phosphorylation of Akt/GSK-3β and MAPKs (ERK1/2, p38 MAPK, and JNK) and pretreatment with their inhibitors, attenuating the rhamnetin-induced cytoprotective effect. Further studies with real time-PCR and a sirtuin inhibitor showed that cardioprotection by rhamnetin occurred through induction of SIRT3 and SIRT4. Conclusions Taken together, these results suggest that rhamnetin may have novel therapeutic potential to protect the heart from ischemia-related injury.

An artificial construct mimicking the intrinsic properties of the natural extracellular matrix in bones has been considered an ideal platform for bone tissue engineering, as it can present an appropriate microenvironment and regulate cell behaviours. In this report, we introduce biodegradable composite scaffolds consisting of polycaprolactone (PCL) and biphasic calcium phosphate (BCP). The scaffolds were fabricated by a salt-leaching process, and the ability of the scaffolds to facilitate osteogenic differentiation was investigated using human mesenchymal stem cells (hMSCs). The scaffolds had an inter-connected porous structure with quadrilateral pores of approximately 200 ∼ 500 μm in width. The mechanical properties of the scaffolds changed as the BCP content was increased in the starting mixture. In the hMSC experiment, although we found that hMSCs adhered to the surface, as well as the inside, of the scaffolds, the incorporated BCP did not increase the proliferation of the hMSCs over 7 days in culture. Interestingly, the alkaline phosphatase (ALP) activity was 4 times higher on the PCL/BCP composite scaffold (0.12 ± 0.03 nmol/min/μg protein) thanon the PCL scaffold (0.03 ± 0.01 nmol/min/μg protein), suggesting that BCP can aid in generating a local environment that promotes bone regeneration. Therefore, a strategy combining polymers and ceramics can be considered a useful platform for bone tissue engineering.

SummaryThe total amounts of N derived from 15N-urea in the organs of 18 newly-bearing “maiden” apple trees and in the soil were determined after 1-year of fertigation with 15N-urea by drip irrigation, scheduled at a soil matric potential of –50 kPa. Prior to this treatment, the 18 “maiden” apple trees had been fertigated with three concentrations of N for 3 years: 17 mg N l–1 (low), 34 mg N l–1 (medium), or 67 mg N l–1 (high), and the same rates of 15N were chosen for treatment comparisons over the following 1 year. The trees were fertiligated with an aqueous stock solution of 15N-labelled urea (1.5 atom % 15N), KH2PO4, and KCl by drip irrigation. The phosphorus (P) and potassium (K) concentrations were constant, and set at 17 mg l–1 and 34 mg l–1, respectively. The total irrigation volume applied per tree was 363 l for the low, 430 l for the medium, and 216 l for the high N treatment.The corresponding supplies of N per tree were 6.17, 14.62, and 14.47 g, respectively. The total amounts of urea-N absorbed...

The variety of arthropod specimen preservation protocols has expanded greatly with the increased interest in preservation of molecular traits such as DNA sequences. While “best practices” for DNA preservation exist, practical limitations often preclude their use. To test the efficacy of propylene glycol as a DNA preservative agent, adult specimens of Cylindera lemniscata (LeConte) (Carabidae: Cicindelinae) and an Athetini sp. (Staphylinidae: Aleocharinae) were stored in 20%, 40%, 60%, 80%, and 100% propylene glycol preservative at room temperature for up to six months. With the exception of the Athetini sp. preserved in 20% propylene glycol, all other treatments yielded the targeted COI gene sequences (ca. 800 base pairs). Propylene glycol appears to be a good preservative for DNA, even at low concentrations and ambient temperatures.

Cordycepin (3'-deoxyadenosine) isolated from Cordyceps militaris, a species of the fungal genus Cordyceps, has been shown to exhibit many pharmacological functions, such as anticancer, anti-inflammatory, and antioxidant activities. In this study, we investigated the preventive role of cordycepin in ischemic/reperfusion (I/R) injury of isolated rat hearts and anesthetized rats. After Sprague-Dawley rats received cordycepin (3, 10, and 30 mg/kg) or control (0.5 % carboxyl methylcellulose) orally once a day for a week, hearts were isolated and mounted on Langendorff heart perfusion system. Isolated hearts were perfused with Krebs-Henseleit buffer for 15-min pre-ischemic stabilization period and subjected to 30-min global ischemia and 30-min reperfusion. Cordycepin administration (10 mg/kg, p.o.) significantly increased left ventricular developed pressure during the reperfusion period compared to that in the control group, but without any effect on coronary flow. Cordycepin (10 mg/kg, p.o.) significantly increased the phosphorylation of Akt/GSK-3β/p70S6K pathways, which are known to modulate multiple survival pathways. In addition, cordycepin decreased Bax and cleaved caspase-3 expression while increasing Bcl-2 expression, Bcl-2/Bax ratio, and heme oxygenase (HO-1) expression in isolated rat hearts. In anesthetized rats subjected to 30 min occlusion of left anterior descending coronary artery/2.5-h reperfusion, cordycepin (1, 3, and 10 mg/kg, i.v.) administered 15 min before the onset of ischemia dose-dependently decreased the infarct size in left ventricle. In conclusion, cordycepin could be an attractive therapeutic candidate with oral activity against I/R-associated heart diseases such as myocardial infarction.

Revision rates of total hip arthroplasty have decreased after introducing total hip arthroplasty (THA) using ceramic component, since ceramic components could reduce components wear and osteolysis. The fracture of a ceramic component is a rare but potentially serious event. Thus, ceramic on polyethylene articulation is gradually spotlighted to reduce ceramic component fracture. There are a few recent reports of ceramic head fracture with polyethylene liner. Herein, we describe a case of a ceramic head component fracture with polyethylene liner. The fractured ceramic head was 28 mm short neck with conventional polyethylene liner. We treated the patient by total revision arthroplasty using 4th generation ceramic on ceramic components.

In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV–vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity.

The present study aimed to investigate the role of yeast extract and silver nitrate on the enhancement of phenylpropanoid pathway genes and accumulation of rosmarinic acid in Agastache rugosa cell cultures. The treatment of cell cultures with yeast extract (500 mg/L) and silver nitrate (30 mg/L) for varying times enhanced the expression of genes in the phenylpropanoid pathway and the production of rosmarinic acid. The results indicated that the expression of RAS and HPPR was proportional to the amount of yeast extract and silver nitrate. The transcript levels of HPPR under yeast extract treatment were 1.84-, 1.97-, and 2.86-fold higher than the control treatments after 3, 6, and 12 h, respectively, whereas PAL expression under silver nitrate treatment was 52.31-fold higher than in the non-treated controls after 24 h of elicitation. The concentration of rosmarinic acid was directly proportional to the concentration of the applied elicitors. Yeast extract supplementation documented the highest amount of rosmarinic acid at 4.98 mg/g, whereas silver nitrate addition resulted in a comparatively lower amount of rosmarinic acid at 0.65 mg/g. In conclusion, addition of yeast extract to the cell cultures enhanced the accumulation of rosmarinic acid, which was evidenced by the expression levels of the phenylpropanoid biosynthetic pathway genes in A. rugosa.

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic characteristics. PVA hydrogels have been formed through chemical crosslinking with aldehyde, photopolymerization and physical crosslinking with freeze-thawing. In this study, crosslinked hydrogels based on PVA, and poly(ethylene glycol) (PEG) were prepared by gamma-ray irradiation, and then annealed at 120 °C. The properties of a hydrogel such as gel fraction, swelling behavior, gel strength as a function of PEG content and annealing time were investigated. Also, the thermal behaviors were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The gel fraction decreases with an increase in PEG content and decrease in annealing time. The tensile strength increases with an increase in annealing time. The thermal behaviors have shown different patterns according to the annealing time. The improved properties suggest that PVA/PEG blend hydrogel can be a good candidate for applications in the articular cartilage.

Gamma-ray irradiation is a very useful tool to improve the physicochemical properties of various biodegradable polymers without the use of a heating and crosslinking agent. The purpose of this study was to investigate the degradation behavior of poly ( l -lactide-co-glycolide) (PLGA) depending on the applied gamma-ray irradiation doses. PLGA films prepared through a solvent casting method were irradiated with gamma radiation at various irradiation doses. The irradiation was performed using 60Co gamma-ray doses of 25–500 kGy at a dose rate of 10 kGy/h. The degradation of irradiated films was observed through the main chain scission. Exposure to gamma radiation dropped the average molecular weight ( M n and M w ), and weakened the mechanical strength. Thermograms of irradiated film show various changes of thermal properties in accordance with gamma-ray irradiation doses. Gamma-ray irradiation changes the morphology of the surface, and improves the wettability. In conclusion, gamma-ray irradiation will be a useful tool to control the rate of hydrolytic degradation of these PLGA films.