Polysiloxane-based hyperbranched fluorescent probe for dynamic visualization of HClO in lysosomes and vivo.

As a type of reactive oxygen species, hypochlorous acid (HClO) is associated with inducing oxidative stress in lysosomes. Once its concentration is abnormal, it may lead to lysosomal rupture and subsequent apoptosis. Meanwhile, this may provide new inspiration for cancer treatment. Therefore, it is crucial to visualize HClO in lysosomes at the biological level. So far, numerous fluorescent probes have emerged to identify HClO. However, fluorescent probes that combine low biotoxicity with lysosome-targetable properties are scarce. In this paper, hyperbranched polysiloxanes were modified by embedding perylenetetracarboxylic anhydride red fluorescent cores with naphthalimide derivative green fluorophores to synthesize novel fluorescent probe (PMEA-1). PMEA-1 was a lysosome-targetable fluorescent probe with unique dual emission, high biosafety, and good response speed. PMEA-1 exhibited excellent sensitivity and responsiveness to HClO in PBS solution and could dynamically visualize HClO fluctuations in cells and zebrafish. Simultaneously, PMEA-1 also had monitoring ability for HClO produced in the process of cellular ferroptosis. In addition, the bioimaging results indicated that PMEA-1 was capable of accumulating within the lysosomes. We anticipate that PMEA-1 will broaden the application of silicon-based fluorescent probes in the field of fluorescence imaging.

Fabrication of a corn stalk derived cellulose-based bio-adsorbent to remove Congo red from wastewater: Investigation on its ultra-high adsorption performance and mechanism.

A cellulose-based bio-absorbent with various and plenty of amino groups was successfully prepared from corn stalk to achieve quantitative removal of Congo red from wastewater with wide pH values (5 ≤ pH ≤ 10). The maximum removal amount was 8.0 mmol·g-1 (5572 mg·g-1) under pH = 6.0 and 45 °C, which was obviously higher than reported absorbents. Investigation on dynamic adsorption and recyclability in authentic wastewater found that the removal efficiency of Congo red was >98 % within 180 min and decreased slightly in industrial water after five cycles, denoting this adsorbent with great potential for environmental application. The characterization results proved that 7.58 mmol·g-1 of different amino groups (-NH2, -NH- and -NR2) were introduced on adsorbent surface by two steps of modification and were the major functional groups for adsorption of Congo red. The inferred adsorption mechanism revealed that Congo red could be adsorbed equivalently on the amino groups by strong electrostatic interactions or hydrogen bonds. Different amino groups played different roles in adsorption due to great differences in protonation ability in 5 ≤ pH ≤ 10. The study was expected to high-efficiently remove Congo red from acidic or alkaline wastewater, and offered an alternative strategy for biowaste treatment of corn stalks in a high value-added manner.

Hyperbranched polysiloxane-based probe with enhanced lipophilicity for visualizing ONOO- fluctuations in endoplasmic reticulum.

The endoplasmic reticulum, a cellular signaling regulator, participates in the synthesis and secretion of many proteins, glycogen, lipids and cholesterol substances. Peroxynitrite (ONOO-) is a highly oxidative and nucleophilic agent. Abnormal fluctuations of ONOO- induce oxidative stress in the endoplasmic reticulum, further disrupting the normal function of protein folding and transport and glycosylation modification, ultimately leading to neurodegenerative diseases, cancer and Alzheimer's disease. Up to now, most probes have tended to achieve targeting functions by introducing specific targeting groups. However, this approach increased the difficulty of the construction process. Therefore, a simple and efficient construction strategy for fluorescent probes with excellent specificity targeting the endoplasmic reticulum is lacking. To overcome this difficulty and put forward an efficient design strategy for the endoplasmic reticulum targeted probes, in this paper, we constructed alternating rigid and flexible polysiloxane-based hyperbranched polymeric probes (Si-Er-ONOO) by bonding perylenetetracarboxylic anhydride and silicon-based dendrimers for the first time. Efficient and specific targeting of the endoplasmic reticulum was successfully achieved by the excellent lipid solubility of Si-Er-ONOO. Furthermore, we observed different effects of metformin and rotenone on the changes of ONOO- volatility in the cellular and zebrafish internal environment by Si-Er-ONOO. We believe that Si-Er-ONOO will expand the application of organosilicon hyperbranched polymeric materials in bioimaging and provide an excellent indicator of reactive oxygen species fluctuations in biological systems.

Mn2+ doped ZnS QDs modified fluorescence sensor based on molecularly imprinted polymer/sol-gel chemistry for detection of Serotonin.

A newly fluorescence probe for detection of Serotonin based on a Mn-doped ZnS quantum dots@silica nanoparticle@molecularly imprinted polymers (QDs@SiO2@MIPs) was successfully created. QDs@SiO2@MIPs were characterized by scanning electron microscope, transmission electron microscope, Fourier transform infrared spectroscopy, UV spectroscopy, X-ray powder diffraction, and fluorescence spectroscopy. A complex was produced between the amino group of QDs@SiO2@MIPs and the hydroxyl group of 5-HT when 5-HT rebinding, the energy of the QDs would be transferred to the complex, which led to its fluorescence quenching. The composite material has a high selectivity with an imprinting factor of 5.96. The linear regression equation is F0/F = 0.0036Cq-0.0512, with a correlation coefficient of 0.9928 in a liner range from 50 to 500 ng/mL. The limit of detection(LOD) was 0.69 ng/mL. The probe exhibited simple preparation process, high sensitivity, good selectivity, low detection limit, short analysis time and could be applied to detect 5-HT in human serum successfully.

[Identification and marker-assisted selection of two major quantitative genes controlling rice sheath blight resistance in backcross generations].

We constructed an F2 clonal population of intercross,Teqing/Lemont, and identified two quantitative trait loci (QTLs) contributing to rice sheath blight resistance on chromosome 9 and 11. The two QTLs were qSB-9 and qSB-11, respectively. From the population, three clonal lines were selected by markers' band types on both sides of these two QTLs, qSB-9 and qSB-11. Two were double-susceptible parent with homozygous susceptible alleles of these two loci,and the other was named as double-resistant parent,of which these two loci were all homozygous resistant alleles. These parents were separately backcrossed to recurrent parents, Teqing or Lemont. From BC2F1, marker-assisted selection was conducted in each proceeding generation and all back-crossed plants in BC2F1 and BC4F1 were inoculated by short toothpicks incubated with a strain, RH-9 of the fungus for identification of the resistance. Results suggested that these two QTLs were selected effectively in each backcross generation and their positions were also verified in identification of resistance to rice sheath blight. In seedling nursery of BC3F2 population, plants were selected through marker-assisted selection, and were separately mixed as homozygous lines of double-susceptible alleles on the background of Teqing, double-susceptible and double-resistant on the background of Lemont. The homozygous lines and their recurrent parents were simultaneously planted on experiment fields of Agriculture Collage of Yangzhou University and Lixiahe District Institute of Agricultural Science. The inoculation was performed by a random-block test with two replicates at each site. The results indicated that 1) The difference of sheath blight disease development was highly significant among materials under the same genetic background,and the order of disease seriousness among different homozygous lines were: double-susceptible line on the background of Lemont > double-susceptible line on the background of Teqing > Lemont > Teqing > double-resistant line on the background of Lemont; 2) When the resistant allele of qSB-9 or qSB-11 solely existed in a plant, its disease rating was reduced about 1.2 score, and 2.0 score when they simultaneously existed on the background of Lemont; 3) No significant interaction between the two QTLs controlling sheath blight resistance and environments was found. These studies have laid a strong groundwork in operation and application, of these QTLs contributing to rice sheath blight resistance.

Effect of hydrophobic/hydrophilic characteristics of magnetic microspheres on the immobilization of BSA.

Core-shell magnetic poly(styrene-acrylamide-acrylic acid) microspheres with carboxyl groups were successfully synthesized via dispersion copolymerization in the presence of nano-particle of Fe(3)O(4). The microspheres were characterized by FTIR spectra. They were used as carrier to immobilize bovine serum albumin (BSA). To investigate the effect of the microsphere surface properties on the immobilization of BSA, a series of microspheres with different hydrophobic/hydrophilic surface characteristics were prepared by adjusting molar percentages of monomers. The results showed that microspheres with different hydrophobicities/hydrophilicities had different immobilized ratios of BSA. In comparison with microspheres having hydrophilic characteristics those with hydrophobic characteristics had a much higher immobilized ratio. The possible reasons for these observations are discussed. In addition, ester activation and coupling times were optimized with respect to immobilized ratio.