Recent Advances in the Biological Responses to Nano-black Phosphorus: Understanding the Importance of Intrinsic Properties and Cell Types.

The production scalability and increasing demand for nano-black phosphorus materials (nano-BPs) inevitably lead to their environmental leakage, thereby raising the risk of human exposure through inhalation, ingestion, dermal, and even intravenous pathways. Consequently, a systematic evaluation of their potential impacts on human health is necessary. This Review outlines recent progress in the understanding of various biological responses to nano-BPs. Attention is particularly given to the inconsistent toxicological findings caused by a wide variation of nano-BPs' physicochemical properties, toxicological testing methods, and cell types examined in each study. Additionally, cellular uptake and intracellular trafficking, cell death modes, immunological effects, and other biologically relevant processes are discussed in detail, providing evidence for the potential health implications of nano-BPs. Finally, we address the remaining challenges related to the health risk evaluation of nano-BPs and propose a broader range of applications for these promising nanomaterials.

Transcriptome Analysis Reveals the Growth Promotion Mechanism of Enteropathogenic Escherichia coli Induced by Black Phosphorus Nanosheets.

With the extensive production and application of black phosphorus (BP) nanosheets, release to the environment is inevitable, which raises concerns about the fate and effects of this two-dimensional (2D) material on sensitive receptors such as environmental microbes. Although the bacterial toxicity of BP nanosheets has been demonstrated, whether the biological response differs in pathogenic and nonpathogenic strains of a microorganism is unknown. Here, enteropathogenic Escherichia coli (EPEC) and nonpathogenic Escherichia coli DH5α (E. coli DH5α), Escherichia coli k12 (E. coli k12), and Bacillus tropicus (B. tropicus) are used to comparatively study the microbial toxicity of BP nanosheets. Upon exposure to BP nanosheets across a range of doses from 10 to 100 µg mL-1 for 12 h, EPEC experienced enhanced growth and E. coli DH5α and E. coli k12 were not affected, whereas B. tropicus exhibited clear toxicity. By combining transcriptome sequencing, proteome analysis, and other sensitive biological techniques, the mechanism of BP-induced growth promotion for EPEC was uncovered. Briefly, BP nanosheets activate the antioxidation system to resist oxidative stress, promote protein synthesis and secretion to attenuate membrane damage, enhance the energy supply, and activate growth-related pathways. None of these impacts were evident with nonpathogenic strains. By describing the mechanism of strain-dependent microbial effects, this study not only highlights the potential risks of BP nanosheets to the environment and to human health but also calls attention to the importance of model strain selection when evaluating the hazard and toxicity of emerging nanomaterials.

Enhancement of triterpene production via in situ extractive fermentation of Sanghuangporus vaninii YC-1.

There have been many studies on the activities and polysaccharide production of Sanghuangporus vaninii. However, few studies have looked at triterpene production from S. vaninii using liquid-state fermentation. A method for enhancing the production of triterpenes by in situ extractive fermentation (ISEF) was studied. Eight solvents were investigated as extractants for triterpene production in the ISEF system. The results showed that using vegetable oil as an extractant significantly increased the yield of total triterpenes and biomass of S. vaninii YC-1, reaching 18.98 ± 0.71 and 44.67 ± 2.21 g/L, respectively. In 5 L fermenter experiments, the added vegetable oil improved the dissolved oxygen condition of the fermentation broth and promoted the growth of S. vaninii YC-1. Furthermore, adding vegetable oil increased the expression of fatty acid synthesis-related genes such as FAD2 and SCD, thereby increasing the synthesis of unsaturated fatty acids in the cell membrane of S. vaninii YC-1. Therefore, the cell membrane permeability of S. vaninii YC-1 increased by 19%. Our results indicated that vegetable oil increased the permeability of S. vaninii YC-1 cell membranes to promote the production of total triterpenes. The use of vegetable oil as an extractant was thus effective in increasing the yield of triterpenes in the ISEF system.

Environmental stability and cytotoxicity of layered black phosphorus modified with Polyvinylpyrrolidone and Zeolitic Imidazolate Framework-67.

Layered black phosphorus (LBP) is regarded as a promising two-dimensional nanomaterial in various application fields. As bare LBP is unstable in humid environment, many modification methods have been developed recently. However, environmental risks of modified LBP nanomaterials are largely unknown. Herein, by sonication and in-situ surface-confined synthesis, polyvinylpyrrolidone (PVP) coated LBP (LBP/PVP), and zeolitic imidazolate framework-67 (ZIF-67) modified LBP (LBP/PVP-ZIF-67) nanomaterials were synthesized. Environmental stability and toxicity of the modified nanomaterials were compared with bare LBP. Results show that LBP/PVP-ZIF-67 exhibits excellent photothermal performance, and higher potential in electrochemical hydrogen evolution than bare LBP or LBP/PVP. Characteristic visible light absorbance at 593 nm was introduced into the nanomaterial by ZIF-67. LBP/PVP has stability in aqueous environment or cytotoxicity similar to LBP. LBP/PVP-ZIF-67 is completely stable in water within 120 h, in contrast to over 30% degradation of LBP or LBP/PVP. More than 50% of LBP in the LBP/PVP-ZIF-67 can degrade to dissolvable phosphorus in oxygenated water after 17 days, indicating the nanomaterial will not be persistent in the environment. Moreover, modification with ZIF-67 can reduce cytotoxicity of LBP. Therefore, this study develops a safe strategy to modify LBP and provides basic information for ecological risk assessment of LBP based materials.

Antrodin A from Antrodia camphorata modulates the gut microbiome and liver metabolome in mice exposed to acute alcohol intake.

This study aimed to investigate the protective effect of Antrodin A (AdA) from Antrodia camphorata (A. camphorata) mycelium on alcohol-induced gut microbiota and liver metabolomic disorders. In acute alcoholic liver injury mice, AdA ameliorated alcoholic exposure-induced hepatic lipid deposition (TC and TG), oxidative stress (MDA), inflammation (TNF-α, IL-1ß, IL-6, IL-17 and IFN-γ), and liver damage via modulating microbiome and metabolomic responses. AdA restored the composition of intestinal flora with an increase in the relative abundance of Lactobacillus and Dubosiella and a decrease in Clostridium_sensu_stricto_1, Lachnospiraceae_NK4A136_group, Prevotellaceae_NK3B31_group, and Prevotellaceae_UCG-001. Besides, AdA favorably regulated alcohol-induced metabolic disorders, including glutathione metabolism (S-(2-hydroxyethyl)glutathione and glutathione oxidized), ascorbate and aldarate metabolism (l-ascorbic acid), and taurine and hypotaurine metabolism (taurine). In conclusion, AdA in A. camphorata is a beneficial active ingredient to treat the microbiomic and metabolic disturbance induced by alcohol intake.

Antrodin A from mycelium of Antrodia camphorata alleviates acute alcoholic liver injury and modulates intestinal flora dysbiosis in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Antrodia camphorata (A. camphorata) is a rare functional fungus in Taiwan and contains a variety of biologically active ingredients. Antrodin A (AdA) is one of the main active ingredients in the solid-state fermented A. camphorata mycelium. It protects the liver from alcohol damage by improving the antioxidant and anti-inflammatory capacity of the liver and maintaining the stability of the intestinal flora. AIM OF THE STUDY: The aim of this study was to evaluate the hepatoprotective activities of ethyl acetate layer extract (EALE), AdA, and Antroquinonol (Aq) from mycelium of A. camphorata on alcoholic liver injury. MATERIALS AND METHODS: Mice were given with intragastrically vehicle (NC, 2% CMC-Na), alcohol (AL, 12 mL/kg bw), or different A. camphorata samples (EALE, AdA, Aq) at low (100 mg/kg bw) or high (200 mg/kg bw) dosages. The positive control (PC) group was given with silymarin (200 mg/kg bw). Except the NC group, each group of mice was fasted for 4 h after the last treatment and was intragastrically administrated with 50% alcohol (12 mL/kg bw). At the end of experiment, mouse serum was collected and the liver was excised. A portion of the liver was fixed in formalin and used for histopathological analysis, whereas the rest was used for biochemical analysis and real-time PCR analysis. The intestinal flora structure of feces was analyzed by determining the v3-v4 region sequence in 16S rDNA. RESULTS: The high-dose groups of the three samples (EALEH, AdAH, and AqH) significantly alleviated the alcohol-induced increases in liver index, serum ALT, AST, and AKP activities. Serum TG level was significantly reduced in all treatment groups. The increase of HDL-C content indicated that active ingredients of A. camphorata could reduce the lipid content in serum. Furthermore, MDA contents of the AdAH and AqH groups in liver were significantly reduced, accompanying with the levels of SOD, CAT, and GSH elevated to various extents. Antioxidant and anti-inflammatory capabilities in the liver were increased in the AdAH group, as evidenced by the mRNA expression levels of Nrf-2 and HO-1 were significantly increased; while those of CYP2e1, TNF-α, and TLR-4 were significantly decreased. Analysis of intestinal flora of feces showed that alcohol treatment significantly changed the composition of intestinal flora. Supplementation with AdA could mitigate dysbiosis of intestinal flora induced by alcohol. Flora of Faecalibaculum, Lactobacillus, and Coriobacteriaceae_UCG-002 showed significantly negative correlations with ALT, AST, AKP, and MDA levels. CONCLUSION: Antrodin A could improve the antioxidant and anti-inflammatory capacities of the liver and maintain the stability of intestinal flora. It is potentially a good candidate compound against acute alcoholic liver injury.

Bacterial toxicity of exfoliated black phosphorus nanosheets.

Newly emerged two-dimensional material, black phosphorus (BP) shows promising applications in many fields owing to its superior properties. Despite the biological effects of BP were studied, its environmental impacts have not yet received enough attention. In this study, the bacterial toxicity of exfoliated BP nanosheets was for the first time evaluated against two model bacteria strains, Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis). By monitoring the bacterial growth curve and colony counting, the bacterial toxicity of BP nanosheets was examined. Higher toxicity was induced for Gram-negative E. coli compared to Gram-positive B. subtilis after 6 h treatment, which was reversed at 12 h due to membrane self-healing of E. coli. The bacterial toxicity followed a time- and concentration-dependent fashion, with a maximum bactericidal efficiency of 91.65% and 99.69% for E. coli and B. subtilis, respectively, after 12 h exposure. Reactive oxygen species (ROS)-dependent oxidative stress and membrane damage were the main bactericidal mechanisms as proved by fluorescence microscopy, flow cytometry, scanning electron microscopy (SEM), and Lactate dehydrogenase (LDH) assay. This study indicates the potential environmental risk of BP nanosheets and the data from this work will guide their safety applications in the future.

Aggregation and conformational change of mushroom (Agaricus bisporus) polyphenoloxidase subjected to thermal treatment.

This study investigated changes in the activity, conformation and microstructure of mushroom polyphenoloxidase (PPO) subjected to thermal treatment. The inactivation of PPO can be achieved by high temperature-short time or mild temperature-long time treatment. Circular dichroism and fluorescence spectra suggested that heating process induced the rearrangement of secondary structure and the disruption of tertiary structure. Red shifts of fluorescence spectra showed positive correlations with the inactivation rate of PPO. There were significant differences in the conformation and molecular microstructure among PPO samples with the same relative activity, which were obtained by treating PPO at 45, 55 and 65°C for different times. In summary, PPO molecules were deformed at mild temperature, while higher temperature induced the formation of large aggregates. PPO with the same relative activity might exist in different forms.

Synthetic biology triggers new era of antibiotics development.

As a discipline to design and construct organisms with desired properties, synthetic biology has generated rapid progresses in the last decade. Combined synthetic biology with the traditional process, a new universal workflow for drug development has been becoming more and more attractive. The new methodology exhibits more efficient and inexpensive comparing to traditional methods in every aspect, such as new compounds discovery & screening, process design & drug manufacturing. This article reviews the application of synthetic biology in antibiotics development, including new drug discovery and screening, combinatorial biosynthesis to generate more analogues and heterologous expression of biosynthetic gene clusters with systematic engineering the recombinant microbial systems for large scale production.

Optimization of medium composition for actinomycin X2 production by Streptomyces spp JAU4234 using response surface methodology.

The effects of cultivation medium compositions including soybean meal, peptone, soybean oil and cornstarch for actinomycin X2 production by Streptomyces spp JAU4234 were accessed by using response surface methodology. The 2(4) full factorial designs and the paths of steepest ascent were effective in searching for the major factors of actinomycin X2 production. In this study, cornstarch and soybean oil showed negative effect on actinomycin X2 production based on the first-order regression coefficients derived from MINITAB software. Subsequently, a central composite design for optimization was further investigated. Preliminary studies showed that soybean meal and peptone were believed to be the major factors for actinomycin X2 production. Estimated optimum compositions for the production of actionmycin X2 were as follows (g/l): soybean meal 21.65 and peptone 9.41, and result in a maximum actionmycin X2 production of 617.4 mg/l. This value was closed to the 612 mg/l actionmycin X2 production from actual experimental observations. The yield of actionmycin X2 was increased by 36.9% by culturing the strain Streptomyces spp JAU4234 in the nutritionally optimized fermentation medium.