Silk fibroin/polycaprolactone-polyvinyl alcohol directional moisture transport composite film loaded with antibacterial drug-loading microspheres for wound dressing materials.

Drug delivery technology can prevent wound infection and inflammatory reactions and accelerate wound healing and quality. In this paper, we propose preparing a multifunctional medical dressing to meet the various needs of people for dressing. A multi-layered composite nanofiber membrane was constructed using silk fibroin as the substrate, and mesoporous silica nanoparticles (MSN) with high adsorption properties were first prepared and then electrosprayed on silk fibroin (SF)/chitosan (CS) microspheres to form MSN-SF/CS microspheres with uniform distribution. Then the MSN-SF/CS microspheres were sprayed on the silk fibroin (SF)/polycaprolactone (PCL)-polyvinyl alcohol (PVA) unidirectional water-conducting composite nanofiber membrane. The test results showed that the encapsulation rate of bovine serum albumin (BSA) by MSN-SF/CS drug-loaded microspheres was 65.53% and the cumulative release rate in vitro was 54.46%. The results of in vitro experiments also showed its good antibacterial effect and good biocompatibility. To eliminate excess wound exudate and reduce inflammation, the cumulative unidirectional transport capacity (AOTC) of 651.75% was achieved by spraying the microspheres on an SF/PCL- PVA unidirectional water conductive composite membrane. This study could stimulate and promote the use of additional wound healing biomaterials in clinical medicine.

Geographic information system-based health risk assessment of rural drinking water in Central China: a case study of You County, Hunan.

This study assessed potential human health hazards posed by drinking water from centralized water supply systems in rural You County, along with its spatial distribution. While most previous studies have focused on source water or urban drinking water, this study evaluated the health risk posed by 20 common pollutants (arsenic, cadmium, chromium(VI), lead, mercury, selenium, cyanide, fluoride, nitrate nitrogen, trichloromethane, tetrachloromethane, chlorite, aluminum, iron, manganese, copper, zinc, ammonia nitrogen, chlorine dioxide, and volatile phenols) in rural terminal tap water. The assessment adopted the model recommended by the US Environmental Protection Agency (EPA) and was combined with the geographic information system (GIS) analysis to explore the spatial distribution of risk factors. Water samples were collected from 13 townships in You County across four quarters of 2019. The results indicated that the average carcinogenic risk of the rural drinking water was 2.45 × 10-5, ranging from 1.80 × 10-5 to 3.89 × 10-5, which never exceeded the maximum acceptable range recommended by the US EPA (1.0 × 10-4 ~ 1.0 × 10-6). The average hazard index (HI), which reflects noncarcinogenic risk levels, was 0.75 and ranged from 0.34 to 1.74. Throughout the year, some townships presented HI > 1, indicating a non-carcinogenic risk. The GIS analysis indicated that noncarcinogenic risks were mainly distributed in the north, followed by the east and west. This is generally consistent with the spatial distribution of chlorite concentrations, which contribute most strongly to noncarcinogenic risk levels. The northern You County should therefore be prioritized for health risk control, followed by the eastern and western regions. Chlorite is the priority pollutant for control.

Synergistic Effect and Characterization of Graphene/Carbon Nanotubes/Polyvinyl Alcohol/Sodium Alginate Nanofibrous Membranes Formed Using Continuous Needleless Dynamic Linear Electrospinning.

In this study, a self-made continuous needleless dynamic linear electrospinning technique is employed to fabricate large-scale graphene (Gr)/carbon nanotubes (CNT)/polyvinyl alcohol (PVA)/sodium alginate (SA) nanofibrous membranes. The synergistic effect of Gr and CNT fillers in the PVA/SA membrane is explored in depth by changing the volume ratio (v/v) of Gr and CNT as 10:0, 8:2, 6:4, 4:6, 2:8, and 0:10. Microstructure, functional group, conductivity, and hydrophilicity of PVA/SA/Gr/CNT membranes was characterized. Results show that the linear electrode needleless electrospinning technique can be spun into 200-nm diameter fibers. The PVA/SA/Gr/CNT fibrous membrane has good hydrophilicity and thermal stability. A Gr/CN ratio of 6:4 possessed the optimal synergistic effect, which showed the lowest surface resistivity of 2.53 × 103 Ω/m2. This study will provide a reference for the large-scale preparation of nanofibrous membrane used as a artificial nerve conduit in the future.

Validation of a rapid and simple high-performance liquid chromatography-electrospray ionization-mass spectrometry method for simultaneous analysis of 15 key chemicals in slimming foods and herbal products.

A rapid and simple high-performance liquid chromatography/electrospray ionization tandem mass spectrometry method was developed for simultaneous analysis of 15 key chemicals in slimming foods and herbal products. These chemicals were strictly restricted adulterants (phenolphthalein, sibutramine, fenfluramine, clopamide, ephedrine, norpseudoephedrine, caffeine and phenformin) and physiologically relevant active components (l-carnitine, nuciferine, aloe-emodin, rhein, emodin, chrysophanol and physcion). In multi-day validations, intra- (n = 5) and inter-day precision (n = 3), limits of detection and limits of quantification for all analytes were 0.60-7.22%, 0.75-9.45%, 0.09-10 µg/L and 0.30-33.3 µg/L, respectively. Mean recovery ranged from 71.4% to 116% for all analytes in three representative samples. The method was validated on 17 samples including 12 kinds of slimming foods and five kinds of herbal products, and was shown to be ideal for routine quantification of 15 key chemicals in slimming foods and herbal products, providing an efficient strategy for quality control and food safety evaluation of weight reducing supplements.

[The Evaluation Value of Methylation Status of CpG Island of SFRP1 and LINE1 Gene Promoter Area in the Prognosis of Hepatocellular Carcinoma.]

OBJECTIVES: To investigate the relationship between aberrant promoter CpG islands methylation status of secreted frizzled related protein 1 (SFRP1) and long intersper sed nuclear element 1 (LINE1) gene and clinicopathologic parameters to determine their prognosis value for hepatocellular carcinoma (HCC). METHODS: 105 cases of HCC and 50 cases of normal people plasma were collected,and then the promoter hypermethylation status of SFRP1 and hypormethylation status of LINE1 were examined by methylation specific PCR (MSP); The relationship between SFRP1/LINE1 methylation status and patients' clinicopathologic factors was analyzed;The association between SFRP1/LINE1 methylation status and disease-free survival and overall survival was analyzed by Kaplan-Meier curves,the log-rank test,and multivariate Cox regression. RESULTS: SFRP1 gene promoter CpG islands hypermethylation and LINE1 gene promoter CpG islands hypomethylation were found in 59.05% (62/105) and 66.67% (70/105) of 105 cancerous plasma cases,repectively,SFRP1 hypermethylation status and LINE1 hypomethylation status in plasma of HCC account for 43.81%(62/105) and no positive methylation cases were detected in normal cases;The hypermethylation status of SFRP1 and hypomethylation status of LINE1 gene were related with HBsAg and α-fetoprotein (AFP) level;There was statistically significant difference between CpG islands hypermethylation of two genes and disease-free survival rate and overall survival rate;The group patients with SFRP1 hypermethylation positive and LINE1 hypomethylation positive demonstrated the worst prognosis while the group with SFRP1 hypermethylation negative and LINE1 hypomethylation negative had the best prognosis. CONCLUSIONS: The promoter methylation of SFRP1 and LINE1 is correlated with the occurrence and development of HCC.SFRP1 and LINE1 might be potential and reliable biomarkers for predicting prognosis in HCC patients.