Microcystins-Loaded Aged Nanoplastics Provoke a Metabolic Shift in Human Liver Cells.

Studies concerning the toxicity of pollutant-loaded nanoplastics (NPs) toward humans are still in their infancy. Here, we evaluated the adsorption of microcystins (MCs) by pristine and aged polystyrene nanoplastics (PSNPs), prepared MCs-loaded aged PSNPS (1, 5, 10, 15, and 19 µg/mg), and systematically mapped the key molecular changes induced by aged and MCs-loaded PSNPs to human hepatoblastoma (HepG2) cells. According to the results, MC-LR adsorption is increased 2.64-fold by aging, and PSNP accumulation is detected in HepG2 cells. The cytotoxicity of the MC-LR-loaded aged PSNPs showed a positive relationship with the MC-LR amount, as the cell viability in the 19 µg/mg loading treatment (aPS-MC19) was 10.84% lower than aged PSNPs; meanwhile, more severe oxidative damage was observed. Primary approaches involved stressing the endoplasmic reticulum and reducing protein synthesis that the aged PSNPs posed for HepG2 cells, while the aggravated cytotoxicity in aPS-MC19 treatment was a combined result of the metabolic energy disorder, oxidative damage, endoplasmic reticulum stress, and downregulation of the MC-LR target protein. Our results confirm that the aged PSNPs could bring more MC-LR into the HepG2 cells, significantly interfere with biological processes, and provide new insight into deciphering the risk of NPs to humans.

Liposomes for effective drug delivery to the ocular posterior chamber.

BACKGROUND: Age-related macular degeneration (AMD) is a leading cause of severe visual deficits and blindness. Meanwhile, there is convincing evidence implicating oxidative stress, inflammation, and neovascularization in the onset and progression of AMD. Several studies have identified berberine hydrochloride and chrysophanol as potential treatments for ocular diseases based on their antioxidative, antiangiogenic, and anti-inflammatory effects. Unfortunately, their poor stability and bioavailability have limited their application. In order to overcome these disadvantages, we prepared a compound liposome system that can entrap these drugs simultaneously using the third polyamidoamine dendrimer (PAMAM G3.0) as a carrier. RESULTS: PAMAM G3.0-coated compound liposomes exhibited appreciable cellular permeability in human corneal epithelial cells and enhanced bio-adhesion on rabbit corneal epithelium. Moreover, coated liposomes greatly improved BBH bioavailability. Further, coated liposomes exhibited obviously protective effects in human retinal pigment epithelial cells and rat retinas after photooxidative retinal injury. Finally, administration of P-CBLs showed no sign of side effects on ocular surface structure in rabbits model. CONCLUSIONS: The PAMAM G3.0-liposome system thus displayed a potential use for treating various ocular diseases.

Microplastics benefit bacteria colonization and induce microcystin degradation.

Microplastics (MPs) can sorb toxic substances and be colonized by microorganisms. However, the interactions between the adsorbed toxic substances and the MPs biofilm remains inadequately understood. Here, a 37-days microcosm experiment was conducted to investigate the influence of polystyrene microplastics (PS-MPs) on microcystin (MC-LR) behavior in turbulent scenarios. The results revealed that adsorption by PS-MPs was the primary process that led to a quick reduction of aquatic MC-LR concentrations. With the colonization of microorganisms on the PS-MPs, the attached biofilm altered the surface properties of PS-MPs, which enhanced the bio-adsorption of MC-LR. Meanwhile, microcystins degrading bacteria, such as Sphingomonadaceae and Methylophilaceae, inhabited in the biofilm, which facilitated the MC-LR biodegradation; this was also demonstrated by the identified MC-LR degradation products. Thus, the MC-LR concentration in water was constantly decreased, with a maximum removal capability of 35.8% in PS-MPs added groups. In addition, a 25% reduction of MC-LR was recorded in PS-MPs added static water. This suggested that the interaction between PS-MPs, biofilm, and MC-LR may be prevalent in natural waters. Our results indicate MPs as vectors for toxic substances could be a double-edged sword (adsorption and biodegradation), which provides new insights for understanding the ecological risks of microplastics.

Cytotoxic effects of polystyrene nanoplastics with different surface functionalization on human HepG2 cells.

Nanoplastics in the environment lead to the human exposure to these particles. However, the consequences of this exposure are not yet fully understood. Here, the cytotoxicity of polystyrene nanoparticles (PS-NPs) with a uniform size (50 nm) but distinct surface functionalization (pristine polystyrene, PS; carboxy and amino functionalized, PS-COOH and PS-NH2, respectively), and at an exposure dosage of 10, 50 and 100 µg/mL, were assessed in the human hepatocellular carcinoma (HepG2) cell line. Although all PS-NPs could be internalized by the HepG2 cells, according to the fluorescent intensities, more of PS-COOH and PS-NH2 than PS, accumulated in the cells. The cell viability was significantly affected in a positively dose-related manner. Functionalized PS-NPs exhibited greater inhibition of cell viability than PS, and the viability inhibition peaked (46%) at 100 µg/mL of PS-NH2 exposure. Superoxide dismutase (SOD) activity was maximum when HepG2 cells were exposed to 10 µg/mL of PS-COOH (1.8 folds higher than that without PS-COOH exposure). The glutathione (GSH) content was maximum when the cells were treated with 50 µg/mL of PS (3.75 fold increase compared to untreated cells). Although the difference in inhibition of cell viability was not significant between PS-NH2 and PS-COOH exposure, 100 µg/mL of PS-NH2 exposure caused the most severe oxidative stress due to dramatically increased accumulation of malondialdehyde (MDA); however, a decrease in the antioxidants levels as the SOD activity and GSH content were also found. The results demonstrated that the cellular oxidative damage occurred and that the antioxidation enzymes may not be able to maintain the balance between the generation of oxidant species and the antioxidant defense. Consequently, 100 µg/mL of PS-NH2 exposure triggered the destruction of antioxidant structures. This study defines the cytotoxic effects of PS-NPs on HepG2 cells and emphasizes the significance of investigating the cytotoxic outcomes of nanoplastics in humans.

Eszopiclone for the treatment of primary insomnia: a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials.

STUDY OBJECTIVE: In this study, we performed a systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials to evaluate the efficacy and safety of eszopiclone for the treatment of primary insomnia. METHODS: We searched MEDLINE, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials and PubMed from inception to June 2018. Additionally, we searched the ClinicalTrials.gov trials register for other relevant trials. According to participants, intervention, comparison, outcome (PICO) criteria, studies were included that focused on: adults diagnosed with primary insomnia, aged 18-65 and > 65 years; eszopiclone for the treatment of primary insomnia; comparison were made between eszopiclone and placebo; as well as primary outcomes, secondary outcomes, and adverse effects. RESULTS: A total of six randomized trials involving 2809 patients with primary insomnia were included in our analysis. Our analysis suggested that eszopiclone was associated with significant improvements in subjective sleep latency, wake after sleep onset, number of awakenings, total sleep time at one week, two weeks, one month, three months and six months. Meanwhile, eszopiclone was associated with increased quality of sleep, ability to function, daytime alertness and sense of physical well-being at one week, one month, three months and six months. Dizziness and unpleasant taste were the most common adverse effects in elderly subgroup. Alternately, non-elderly patients may be more prone to adverse effects such as infection, pharyngitis, somnolence, unpleasant taste and dry mouth. CONCLUSION: This meta-analysis showed that eszopiclone is an effective and safe therapy option for patients with primary insomnia, especially in elderly patients. However, due to the high clinical heterogeneity in some outcomes, further standardized preparation, large-scale and rigorously designed trials are needed.

Water-soluble UV curable urethane methyl acrylate coating: preparation and properties.

Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous solutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.

Reduced graphene oxide films used as matrix of MALDI-TOF-MS for detection of octachlorodibenzo-p-dioxin.

A reduced graphene oxide (rGO) film was used as the matrix in the matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy (MALDI-TOF-MS) for the detection of octachlorodibenzo-p-dioxin (OCDD) with a detection weight as low as 500 pg.