Revealing the relationship between molecular weight of lignin and its color, UV-protecting property.

Lignin has great potential as a natural, green, and sustainable broad-spectrum sunscreen active ingredient. However, the coexistence of dark color and sunscreen properties hinders its application in cosmetics. In this study, we focus on the effects of the molecular weight of lignin on tis UV-protecting property and color in order to prepare lignin-based sunscreen with high performance. A prepared sunscreen containing low molecular weight lignin (F5, <1000 g/mol) exhibits good UV-protecting property (sun protection factor (SPF) = 7.14) and light color advantages (ΔE = 46.2). Moreover, a strong synergistic effect on UV-protecting property exists between low molecular weight lignin and ethylhexyl methoxycinnamate (EHMC), resulting in high SPF of F5@EHMC-based sunscreen (55.56). Additionally, added TiO2 can efficiently mitigate the dark color of lignin-based sunscreens due to prominent covering power of TiO2. Moreover, lignin-based sunscreens have good biocompatibility with HaCaT cells. This work is useful for understanding the mechanism of the UV-protecting property and dark color of lignin, and for designing an efficient and safe lignin-based sunscreen.

Novel microporous ß-cyclodextrin polymer as sorbent for solid-phase extraction of bisphenols in water samples and orange juice.

A new microporous ß-cyclodextrin polymer (MP-CDP) was prepared for the simultaneous solid-phase extraction (SPE) of bisphenol F (BPF), bisphenol A (BPA) and bisphenol AF (BPAF). The MP-CDP was characterized by Fourier transform infrared spectroscopy, solid-phase 13C nuclear magnetic resonance, thermo-gravimetric analysis, scanning electron microscopy, and nitrogen adsorption and desorption analysis. Results indicated that the MP-CDP had micron-level particle size, microporous structure, a high BET surface area, and a high product yield. Adsorption tests showed that the MP-CDP sorbent had high adsorption ability and fast binding kinetics for bisphenols. Moreover, the MP-CDP presented high extraction efficiencies, high enrichment factor, good reusability and good batch-to-batch reproducibility for SPE of bisphenols. Based on the MP-CDP sorbent, a SPE-HPLC-UV method was developed and successfully applied to simultaneously detect three bisphenols in water samples and orange juice with the recoveries of 95.7-106.3% (RSD = 2.0-5.2%) for BPF, 92.9-107.0% (RSD = 1.5-5.1%) for BPA, and 96.0-103.5% (RSD = 1.7-5.0%) for BPAF, respectively. The limit of detection (S/N = 3) and the limit of quantification (S/N = 10) for all bisphenols in these samples were 0.15 ng/mL and 0.5 ng/mL, respectively. The new MP-CDP can be potentially utilized as a good sorbent for simultaneous SPE of trace bisphenols in environmental water samples and beverages.

Effect of recombinant hPTEN gene expression on PDGF induced VSMC proliferation.

Human phosphatase and tensin homolog (hPTEN) gene was expressed in vascular smooth muscle cells (VSMCs) to study its effect on VSMC proliferation induced in platelet-derived growth factor (PDGF) conditioned medium. After G418 selection, MTT assay was conducted to examine transfected VSMC proliferation induced in human PDGF conditioned medium. We successfully constructed eukaryotic expression vector pcDNA4/myc-His-PTEN and transferred into VSMC cells. We report that in vitro proliferation of VSMC was inhibited in PTEN transfected VSMCs induced in PDGF conditioned medium. RT-PCR and Western blot results indicated significantly high levels of protein kinase B-PKB and nuclear factor kappa B mRNA and protein, respectively, in PDGF group as compared with the control group.

[Association between hand-foot-and-mouth disease in Xi'an and enterovirus 71].

OBJECTIVE: To isolate the prevalent strain of enterovirus 71 (EV71) in Xi'an area in 2008, and compare the concordance of viral isolation, reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescent technique in detecting EV71, find the fast and effective method for detection, and analyze the differences between the EV71 strains isolated from Xi'an and Fuyang, Anhui. METHOD: Virus isolation and RT-PCR were carried out on vesicle fluid and throat swab specimens that were collected from the patients with hand-foot-and-mouth disease, RD and HEp-2 cell lines were used for viral isolation. The virus was identified by using immunofluorescence technique. Nucleotide sequencing was performed on positive product of RT-PCR, and compared with EV71 isolated from Fuyang in 2008, then submitted to Genbank. RESULT: Among the 56 samples of throat swab inoculated on RD and HEp-2 cells, the positive rates were 5.4% (3/56) and 1.8% (1/56), respectively. Among the 56 samples of vesicle fluid inoculated on RD and HEp-2 cells, the positive rates were 12.5% ( 7/56 ) and 5.4% (3/56), respectively. Cytopathic effect of RD and HEp-2 cells appeared on days 7 and 10, respectively. The positive rates of RT-PCR on throat swab and vesicle fluid samples were 21.4% (12/56) and 33.9% (19/56), respectively. Cytopathic effect was found in cell culture for 14 cases and immunofluorescence, showed that 9 of them were infected with EV71. The authors obtained the EV71 strain prevalent in Xi'an during 2008. The nucleotide sequence was submitted to the NCBI Genbank and gained the accession number EU812461. CONCLUSION: The EV71 in Xi'an prevalent during 2008 may have a weaker epithelial tropism. Comparison of the EV71 strain isolated from Xi'an with EU703812, EU703813 and EU703814 isolated from Fuyang, Anhui showed that the homology was 97%-98%. RT-PCR is an important method for rapid detection of EV71.