Development of biomaterials based on plasticized polylactic acid and tea polyphenols for active-packaging application.

Bioactive-packaging films based on polylactic acid (PLA), acetyl tributyl citrate (ATBC), and tea polyphenol (TP) were prepared by melt blending. Results of mechanical-property test revealed that adding ATBC and TP can significantly improve mechanical properties of PLA. The shift of CO to lower wavelengths in FTIR and the morphology of the films in SEM indicated physical or chemical interactions in the PLA/ATBC/TP films. The antioxidant, and antibacterial activities of the PLA/ATBC films increased dramatically (P<0.05) with increased TP amount. The antioxidant activity of the films with 1 % TP was equivalent to that of 300 mg/L l-ascorbic acid, whereas PLA/ATBC/TP films with 0.5 % and 1 % TP concentration were effective in inhibiting Staphylococcus aureus and Escherichia coli within almost 5 h (P<0.05). The PLA films changed from transparent to opaque and from yellow to red after combining with ATBC or TP, respectively. The overall migration of the films in 3 % acetic acid and 10 % ethanol did not exceed the overall migration limit. All these findings indicated potential of the PLA/ATBC/TP films in active-packaging application.

Preparing potato starch nanocrystals assisted by dielectric barrier discharge plasma and its multiscale structure, physicochemical and rheological properties.

Non-thermal plasma has increasingly been used for surface modification of various materials as a novel green technology. In this study, we prepared potato starch nanocrystals (SNCs) assisted by dielectric barrier discharge plasma technology and investigated its multiscale structure, physicochemical properties and rheology. Plasma treatment did not change the morphology and crystalline pattern of SNCs but reduced the crystallinity. The amylose content, swelling power, gelatinization temperature, and apparent viscosity of SNCs decreased after the plasma process by depolymerizing the amylopectin branch chains and degrading SNCs molecules. Besides, plasma increased the rapidly digestible starch and resistant starch content. Changes in rheological properties of plasma treated SNCs suggested that the plasma process increased the flowing capacity. The effective structural and functional changes of plasma treated SNCs confirm that plasma technology has great potential for modification of SNCs.

The molecular structure, morphology, and physicochemical property and digestibility of potato starch after repeated and continuous heat-moisture treatment.

The multiscale structural, physicochemical, and digestible properties of potato starch before and after heat-moisture treatment were investigated, and further compared between repeated heat-moisture treatment (RHMT) and continuous heat-moisture treatment (CHMT). After heat-moisture treatment, there appeared partial disruption and pits on the starch granules, and the birefringence edges of HMT starch particles became blurred. Besides, the molecular weight of samples conspicuously decreased after two kinds of treatments. The crystal type of HMT starches transformed from B-type to C-type according to X-ray analysis. A decrease in the solubility and swelling power in high temperatures were identified. The pasting temperature, the gelatinization transition temperature (To , Tp , Tc ), and the slowly digestible starch (SDS) content of HMT starches were significantly higher than native potato starch, while the peak viscosity, the trough viscosity, the final viscosity, the breakdown, and the gelatinization enthalpy (ΔH) of RHMT and CHMT potato starches decreased compared to the native. RHMT potato starches displayed significantly higher relative crystallinity degree and gelatinization transition temperatures. The cooling process of RHMT in which the linkage between the recombinant amylose/amylopectin was enhanced compared with CHMT, which contributed to that RHMT potato starches exhibited greater advantages in practical applications. PRACTICAL APPLICATION: The described RHMT and CHMT starches provide new ideas for the study of modified starch. Furthermore, this study revealed the mechanism of heat-moisture processing provided some instructions to the application of RHMT potato starch.

Physical and structural properties of potato starch modified by dielectric treatment with different moisture content.

The altered morphology, amylose content, microstructure, viscosity and thermal properties of potato starch after heating by radio frequency (RF) and microwaves (MW) were studied and contrasted with the native potato starch. The results showed that the MW treatment roughens the starch surface and lowers the amylose content of the starch, even more than the RF-treated starch does. The starch granule size of MW treated was larger than RF treated. RF treatment altered the structure and reduced the crystallinity of the starch, but the MW treatment did not affect the crystal form. The gelatinization temperature of the MW-treated starch was higher than the native potato starch, while the RF-treated starch was lower than the native starch. The results also indicated that the peak viscosity and the breakdown viscosity values of the RF-treated starch consistently surpassed that of the MW-treated starch. The results exposed the facts that RF treated starch showed the same trend on crystal and pasting properties compared with the hot water annealing starches, which suggested RF can be an efficient method for starch annealing.

[Transdermal characteristics and mechanism of asiaticoside nanoemulsions and asiaticoside nanoemulsions-based gels].

To prepare the asiaticoside nanoemulsions (ASI-NEs) and asiaticoside nanoemulsions-based gels (ASI-NBGs), compare them with the commercial cream of asiaticoside (ASI-C) in terms of transdermal characteristics, and investigate the transdermal mechanism of ASI-NEs and ASI-NBGs. Their transdermal characteristics were studied by using Franz diffusion cells. The effect of topical ASI-NEs and ASI-NBGs on ultrastructure of rabbit skin was evaluated by using HE staining method. The localization and the permeation pathway of asiaticoside were visually investigated by using laser scanning confocal microscope (CLSM). The transdermal studies in vitro showed that the cumulative amount of ASI permeated from ASI-NEs and ASI-NBGs at 12 h after application were (3 504.30±180.93), (1 187.40±128.88) µg·cm⁻² respectively, 6.57, 2.23 times of that in the control group of ASI-C; the drug deposition of ASI-NEs and ASI-NBGs in skin was (159.48±7.47), (120.53±5.71) µg·cm⁻² respectively, 5.93, 4.48 times of that of ASI-C. HE staining of the rabbit skin after application of ASI-NEs and ASI-NBGs showed that the epidermis structure was basically intact; stratum corneum was loosed and the keratin fragment was increased; at the same time, the gap of prickle cell was increased and the basal cells were arranged loosely. The study of CLSM showed that significant percutaneous enhancer effect was observed for ASI-NEs after the topical application of 6 h, as the fluorescent compound was penetrated in the dermis and diffused uniformly. The fluorescence area and the integral optical density (IOD) were 28.81, 32.51 times of that in the FITC aqueous solution group, respectively. The fluorescent preparations showed strong fluorescence in the epidermis, but weak in deeper layers; with the increase of treatment time, the fluorescence in deeper layer was increased and stronger in skin appendages. The prepared ASI-NEs and ASI-NBGs have good transdermal characteristics and the transdermal mechanism is related to breaking the ultrastructure of stratum corneum and penetrating by the path of skin adnexa.

De novo transcriptome analysis of Inonotus baumii by RNA-seq.

Inonotus baumii, a basidiomycete white rot fungus, has been widely used as traditional herbal medicine in China, Korea, Japan and other Asian countries for many years. Its extract is of great medicinal importance and plays a valuable role in the immune response and disease resistance. However, limited genetic resources for I. baumii have hindered exploration of this species. In order to gain a molecular understanding of this fungus, Illumina high-throughput technology was used to sequence and analyze the transcriptome of I. baumii, and 280,691 contigs, 43,890 scaffolds and 30,051 unigenes were obtained. Additionally, based on similarity search with known proteins, unigenes were annotated with gene descriptions, gene ontology (GO), clusters of orthologous group (COG), and database of protein families (Pfam) terms. According to the annotation of unigenes, a total of 12 candidate genes involved in the triterpenoid biosynthesis pathway and 21 putative FOLymes (fungal oxidative lignin enzymes) and 176 CAZymes (carbohydrate-active enzymes) were obtained using homology-based BlastX. Moreover, for better understanding of the transcripts function, the BlastX algorithm was used to search for homologous sequences against the Yeast genome. This is the first study on transcriptome analyses of I. baumii, which provided a dataset for functional gene mining and laid a basis for further functional genomics studies of I. baumii.

Honeysuckle-encoded atypical microRNA2911 directly targets influenza A viruses.

Influenza A viruses (IAVs), particularly H1N1, H5N1 and H7N9, pose a substantial threat to public health worldwide. Here, we report that MIR2911, a honeysuckle (HS)-encoded atypical microRNA, directly targets IAVs with a broad spectrum. MIR2911 is highly stable in HS decoction, and continuous drinking or gavage feeding of HS decoction leads to a significant elevation of the MIR2911 level in mouse peripheral blood and lung. Bioinformatics prediction and a luciferase reporter assay showed that MIR2911 could target various IAVs, including H1N1, H5N1 and H7N9. Synthetic MIR2911 significantly inhibited H1N1-encoded PB2 and NS1 protein expression, but did not affect mutants in which the MIR2911-binding nucleotide sequences were altered. Synthetic MIR2911, extracted RNA from HS decoction and HS decoction all significantly inhibited H1N1 viral replication and rescued viral infection-induced mouse weight loss, but did not affect infection with a mutant virus in which the MIR2911-binding nucleotide sequences of PB2 and NS1 were altered. Importantly, the inhibitory effect of HS decoction on viral replication was abolished by an anti-MIR2911 antagomir, indicating that the physiological concentration of MIR2911 in HS decoction could directly and sufficiently suppress H1N1 viral replication. MIR2911 also inhibited H5N1 and H7N9 viral replication in vitro and in vivo. Strikingly, administration of MIR2911 or HS decoction dramatically reduced mouse mortality caused by H5N1 infection. Our results demonstrate that MIR2911 is the first active component identified in Traditional Chinese Medicine to directly target various IAVs and may represent a novel type of natural product that effectively suppresses viral infection.

[Bibliometrics of woody medical plants in China].

Using the theory and method of bibliometrics, this paper made statistical analysis on the research papers of 16 main woody medical plants published in the period of 1998-2007, from aspects of years distribution, journals distribution, themes distribution, authors distribution and research institutes distribution, and so on. The results showed the studies, status quto and development potential of woody medical plants.

Steroid regulation of proliferation and osteogenic differentiation of bone marrow stromal cells: a gender difference.

Bone marrow mesenchymal stem cells (MSCs) are considered a potential cell source for stem cell-based bone tissue engineering. However, noticeable limitations of insufficient supply and reduction of differentiation potential impact the feasibility of their clinical application. This study investigated the in vitro function of steroids and gender differences on the proliferation and differentiation of rat MSCs. Bone marrow MSCs of age-matched rats were exposed to proliferation and osteogenic differentiation media supplements with various concentrations of 17beta-estradiol (E2) and dexamethasone. Cell proliferation was measured by MTS assay; osteogenic markers and steroid-associated growth factors and receptors were evaluated by ELISA and real-time PCR. The results revealed that supplements of E2 and dexamethasone increase MSC proliferation in a biphasic manner. The optimal dose and interaction of steroids required to improve MSC proliferation effectively varied depending on the gender of donors. Supplementation of E2 effectively improves osteogenic differentiation markers including ALP, osteocalcin and calcium levels for MSCs isolated from both male and female donors. The mRNA of TGF-beta1 and BMP-7 are also up-regulated. However, effective doses to maximally improve osteogenic potentials and growth factors for MSCs are different between male and female donors. The relationship between steroid receptors, osteogenic markers and cytokines are also varied by genders. The outcomes of the present study strongly indicate that steroids potentially function as an effective modulator to improve the capacity of MSCs in bone regeneration. It provides crucial information for improving and optimizing MSCs for future clinical application of bone regeneration.

Studies on the amino acid and mineral content of buckwheat protein fractions.

Protein fractions were extracted by successive extraction and analysis method in four buckwheat varieties including Japanese spring buckwheat, Japanese summer buckwheat, Yuqiao No. 1 and Yuqiao 6-21. The amino acid and the mineral content of each protein fraction were also analyzed in this paper. The basis for the data on the experiment was the relationship between protein fractions and amino acids, and the mineral contents of protein fractions. The distribution and proportion of amino acids and the minerals in each protein fraction in the buckwheat kernel as well as the nutritional value of buckwheat kernel were discussed. The results showed that there is a high amount of soluble protein and very low amount of prolamin in the buckwheat kernel. Leucine is the first limited amino acid in buckwheat, and buckwheat protein is only a seminutritional protein. The buckwheat kernel is rich in K, Zn in the albumin, Ca, Mg and Mn in the globulin, Na in the prolamin and glutelin.