Self-Assembled pH-Responsive Metal-Organic Frameworks for Enhancing the Encapsulation and Anti-Oxidation and Melanogenesis Inhibition Activities of Glabridin.

Metal organic frameworks (MOFs) are formed by self-assembly of metal ions and organic ligands. A special type of MOF called ZIF-8, which is formed by self-assembly of zinc ions and 2-methylimidazole, shows excellent stability in aqueous solutions and disintegrates under acidic conditions. These properties make ZIF-8 a suitable carrier material for pH-stimulated drug delivery systems. Glabridin is an isoflavane compound that is widely present in the roots of licorice. Because of its outstanding skin whitening properties, glabridin is widely used as a whitener in the cosmetics industry. In this study, ZIF-8 was employed to encapsulate glabridin. Glabridin-loaded ZIF-8 was successfully prepared with a drug encapsulation efficiency of 98.67%. The prepared sample showed a fusiform or cruciate flower-like structure, and its size was about 3 µm. ZIF-8 enabled pH-controlled release of glabridin. Moreover, ZIF-8 encapsulation significantly enhanced the intracellular anti-oxidant activity and melanogenesis inhibitory activity of glabridin. This study provides a new approach that shows great potential to improve the biological application of glabridin.

[Research on ground scenery spectral radiation source with tunable spectra].

A spectrum-tunable ground scenery spectrum radiation source, using LEDs and bromine tungsten lamp as luminescence media, was introduced. System structure and control of the spectrum radiation source was expounded in detail. In order to simulate various ground scenery spectrum distribution with different shapes, a ground scenery spectral database was established in the control system. An improved genetic algorithm was proposed, and a large number of ground scenery spectra were produced by the simulator. Spectral similarity and the average spectral matching error of several typical ground scenery spectra were further analyzed. Spectral similarity of red bands, green bands, blue bands and near-infrared spectral band also was discussed. When the radiance of the target was 50 W x (m2 x sr)(-1), the average spectral matching error was less than 10% and spectral similarity was greater than 0.9, up to 0.983. Spectral similarity of red band, green band, blue band and near-infrared band (especially green band and near-infrared band) was less than that of full-band. Compared with blue band and red band, spectral similarity of green band and near-infrared band low-amplitude maximum can rearch 50%. Ground scenery spectrum radiation source can be used as radiometric calibration source for optical remote sensor, and calibration error, which is caused by objectives and calibration sources spectral mismatch, can be effectively reduced.

[Measurement of relative spectral responsivity of photodetector by LED-based spectrum-tunable source].

A method of determining relative spectral responsivity of photodetector by LED-based spectrum-tunable integrating sphere source is put forward, and the measuring principle and algorithm are exhaustively described. In the course of calculation, the radiant transmission integral equation was changed into summation formula, and the degree of approximation between integral value and summation value is related to the selected wavelength interval. The differences between integral value and summation value in different wavelength intervals of Si photodiode and CCD were simulated and analyzed. The simulated results demonstrated that the relative differences between signal integral value and signal summation value of Si photodiode and CCD were below 0.2% in 10 nm interval, so 10 nm interval was an ideal choice. In the end, the factors affecting measurement accuracy were discussed and the solution suggestions were given. This method is easy in structure, and it avoids the measurement transmission errors of some instruments, such as monochromator.

Differential response of the soil nutrients, soil bacterial community structure and metabolic functions to different risk areas in Lead-Zine tailings.

Rapid growth in the mining industry has brought about a large formation of tailings, which result in serious destruction of the ecological environment and severe soil pollution problems. This study assesses soil nutrients, soil bacterial community and soil microbes' metabolic function in heavily polluted areas (W1), moderately polluted areas (W2), lightly polluted areas (W3) and clean areas (CK) using 16S Illumina sequencing. The results of this study showed that compared with CK, a severe loss of soil nutrients and richness of OTUs (Chao1 and ACE indices) were observed with the aggravated pollution of tailings. The Chao1 and ACE indices in the W1 group decreased significantly by 15.53 and 16.03%, respectively, (p < 0.01). Besides, the relative abundance of Actinobacteria and Proteobacteria was high whereas and relative abundance of Chloroflexi in the polluted areas. Among them, W1 groups increased significantly the relative abundance of Actinobacteria and decreased significantly the relative abundance of Chloroflexi, these can be used as indicator phyla for changes in soil community structures under polluted stress. Tax4 Fun analysis showed that W1 groups affected the soil bacterial community and altered the primary types of biological metabolism in polluted areas. Tailings have adverse impacts on soil bacterial community and metabolic functions, and the deterioration in soil quality is dependent on the levels of tailings pollution. Cumulatively, this study provides valuable information on the bacterial community structure and metabolic functions in the tailing polluted soil.

[Analysis of Soil Bacterial Community Structure and Ecological Function Characteristics in Different Pollution Levels of Lead-zinc Tailings in Datong].

A rapid rise in industrialization has led to the accumulation of copious mining waste, which has caused serious destruction of the ecological environment, resulting in severe pollution problems that need to be addressed urgently. In this study, altered soil bacterial communities in different polluted areas were analyzed using the Illumina high-throughput sequencing technique. The primary factors along with physical and chemical factors influencing the soil bacterial communities were also investigated, and the associated potential ecological functions were predicted. The results of these analyses indicated that aggravated pollution caused severe loss of tailing soil nutrients. A total of 14253 bacterial OTU was obtained from the soil samples. The total numbers of OTU in the heavily polluted area (W1), moderately polluted area (W2), lightly polluted area (W3), and clean area (CK) were 3240, 3330, 3813, and 3870, respectively. However, the soil OTUs decreased gradually with increasing pollution. In the α-diversity index analysis, the richness and evenness of the soil bacterial community were significantly decreased in the W1 group. A significant decrease in the Chao1, ACE, and Shannon indexes was also observed in the W1 group, whereas no significant difference was observed in the W3 group compared to the control. The dominant bacterial phyla identified in the soil wereß-Actinobacteria, ß-Proteobacteria, and ß-Chloroflexi. Further, the relative abundance of ß-Actinobacteria and ß-Proteobacteria was high, whereas relative abundance of ß-Chloroflexi in the W1-W3 groups was low compared to that in the control. The relative abundance of the dominant phylum in the W1 group was significantly different than that in the CK group (P<0.05). RDA showed that the soil physical and chemical properties selected in this study explained the total variation in soil bacterial community by 93.35%. Spearman analysis showed that ß-Actinobacteria was negatively correlated with nitrogen source and organic matter and positively correlated with pH; ß-Proteobacteria was negatively correlated with nitrogen source, phosphorus source, available potassium, and organic matter and positively correlated with total potassium and pH; and ß-Chloroflexi was positively correlated with nitrogen source, phosphorus source, available potassium, and organic matter and negatively correlated with pH. Tax4 Fun was used to analyze the biological metabolic pathway. Heavy metal pollution in the soil affected the soil bacterial community and changed the main types of biological metabolism. The ecological functions of soil bacteria groups in different polluted areas were predicted by FAPROTAX. The results showed that the dominant metabolic patterns were affected by the pollution degree, and the metabolic patterns of soil bacteria in polluted areas were relatively single. The functional abundance of metabolic patterns of soil bacteria communities in CK was higher than that in polluted areas, which not only participated in degradation metabolism but also related to oxidation metabolism.

Enhancing remediation potential of heavy metal contaminated soils through synergistic application of microbial inoculants and legumes.

Soil microorganisms play a crucial role in remediating contaminated soils in modern ecosystems. However, the potential of combining microorganisms with legumes to enhance the remediation of heavy metal-contaminated soils remains unexplored. To investigate this, we isolated and purified a highly efficient cadmium and lead-tolerant strain. Through soil-cultivated pot experiments with two leguminous plants (Robinia pseudoacacia L. and Sophora xanthantha), we studied the effects of applying this microbial agent on plant nutrient uptake of soil nutrients, heavy metal accumulation, and the dynamics of heavy metal content. Additionally, we examined the response characteristics of inter-root microbial and bacterial communities. The results demonstrated that microorganisms screened from heavy metal-contaminated soil environments exhibited strong survival and adaptability in heavy metal solutions. The use of the Serratia marcescens WZ14 strain-phytoremediation significantly increased the soil's ammonium nitrogen (AN) and organic carbon (OC) contents compared to monoculture. In addition, the lead (Pb) and cadmium (Cd) contents of the soil significantly decreased after combined remediation than those of the soil before potting. However, the remediation effects on Pb- and Cd-contaminated soils differed between the two legumes following the Serratia marcescens WZ14 inoculation. The combined restoration altered the composition of the plant inter-rhizosphere bacterial community, with the increase in the relative abundance of both Proteobacteria and Firmicutes. Overall, the combined remediation using the tolerant strain WZ14 with legumes proved advantageous. It effectively reduced the heavy metal content of the soil, minimized the risk of heavy metal migration, and enhanced heavy metal uptake, accumulation, and translocation in the legumes of S. xanthantha and R. pseudoacacia. Additionally, it improved the adaptability and resistance of both legumes, leading to an overall improvement in the soil's environmental quality. These studies can offer primary data and technical support for remediating and treating Cd and Pb in soils, as well as rehabilitating mining sites.

Calcium phosphate coated core-shell protein nanocarriers: Robust stability, controlled release and enhanced anticancer activity for curcumin delivery.

Composite protein and inorganic nanodelivery systems can realise a pH-responsive release and effectively improve the stability and anti-cancer proliferative activity of hydrophobic molecules. In this study, a novel core-shell structure of NaCas (Sodium Caseinate)@CaP (Calcium Phosphate) as a nanodelivery system with NaCas as the core for increasing solubility and CaP as the shell for enhanced stability was built. By using Cur (Curcumin) as a model bioactive molecule, (Cur@NaCas)@CaP nanoparticles (NPs) demonstrated a uniform size distribution of 150-200 nm with a distinct nano-composite structure. After exposure to 80 °C for 2 h, the NaCas@CaP loaded Cur still retained 80% stability while under the same conditions only 12% of free Cur remained intact. UV-light stability was remarkably enhanced 8.56 fold by the protection of the core-shell structure. More importantly, pH-responsive release was achieved owing to the CaP surface coating. The encapsulated Cur by NaCas@CaP NPs exhibited an enhanced cellular anti-oxidant activity (CAA) based on MGC-803 cell monolayer models. The confocal laser-scanning microscopy (CLSM) images and cancer-cell-proliferation assay illustrated that (Cur@NaCas)@CaP NPs showed significantly improvements of cellular uptake and anti-cancer activity against A549 cancer cells than free Cur. These novels core-shell NaCas@CaP NPs are very promising for intensifying the stability and bioactivity of hydrophobic compounds in drug delivery and cancer treatment.

Crystal-Seeded Growth of pH-Responsive Metal-Organic Frameworks for Enhancing Encapsulation, Stability, and Bioactivity of Hydrophobicity Compounds.

Zeolitic imidazolate framework-L (ZIF-L) could effectively improve the stability, controlled release, and anticancer activity of natural hydrophobicity drugs in drug delivery systems (DDSs). A simple and universal strategy was developed to prepare the curcumin-loaded ZIF-L (CCM@ZIF-L) by the antisolvent coprecipitation method, which was different from the traditional approaches. The microcrystal molecules of curcumin were used as the core of ZIF-L growth to form CCM@ZIF-L, which has a very high drug encapsulation efficiency of 98.21% and a regular leaf or cruciate flower-like structure. The formation of CCM@ZIF-L with a distinct composite structure was supported by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared, powder X-ray diffraction, and zeta-potential. Because of the protective effect of ZIF-L, CCM@ZIF-L exhibited excellent stability and about a 5-fold increase in temperature stability over free curcumin. CCM@ZIF-L exhibited controlled drug release behavior in simulated in vitro tumor microenvironments (almost 81.2% drug release over a period of 72 h). Furthermore, confocal laser scanning microscopy results and cytotoxicity experiments confirmed that the encapsulated curcumin showed a significant improvement in cellular uptake and anticancer activity against A549 cancer cells. Moreover, the curcumin encapsulated in ZIF-L exhibited remarkable cellular antioxidant activity based on MGC-803 cell models. This work presents a novel approach to solve the drug loading problem by employing ZIF-L and exhibits enormous potential of ZIF-L as an effective DDS in cancer treatments.