Risk assessment and microbial community structure in agricultural soils contaminated by vanadium from stone coal mining.

High health risks of vanadium (V) released by the mining of vanadium titanomagnetite (VTM) have been widely recognized, but little is known about the risks and microbial community responses of V pollution as a consequence of the stone coal mining (SCM), another important resource for V mining. In this study, the topsoils and the profile soils were collected from the agricultural soils around a typical SCM in Hunan Province, China, with the investigation of ecological, health risks and microbial community structures. The results showed that ∼97.6% of sampling sites had levels of total V exceeding the Chinese National standard (i.e., 130 mg/kg), and up to 41.1% of V speciation in the topsoils was pentavalent vanadium (V(V)). Meanwhile, the proportions of HQ > 1 and 0.6-1 in the topsoils were ∼8.3% and ∼31.0% respectively, indicating that V might pose a non-carcinogenic risk to children. In addition, the microbial community varied between the topsoils and the profile soils. Both sulfur-oxidizing bacteria (e.g. Thiobacillus, MND1, Ignavibacterium) and sulfate-reducing bacteria (e.g. Desulfatiglans, GOUTB8, GOUTA6) might have been involved in V(V) reductive detoxification. This study helps better understand the pollution and associated risks of V in the soils of SCM and provides a potential strategy for bioremediation of the V-contaminated environment.

Heavy metal pollution in a black shale post-mining site of southern China: Pollution pattern, source apportionment and health risk assessment.

Source apportionment is critical but remains largely unknown for heavy metals in the soil surrounding black shale mining areas. Herein, the distribution, potential hazards, and sources of heavy metals in the soil around a black shale post-mining site were investigated. The content of Cadmium (Cd) in topsoil samples (0.77-50.29 mg/kg, N = 84) all exceeded the Chinese agricultural soil standard (0.3 mg/kg). The majority of Cd in the soil existed in the mobile fraction posing a high potential risk to the local ecosystem. and Zn and V in soils existed in the residual form. The percentages of HQing > 1 and 0.6-1 for Vanadium (V) in soil were 8.3% and 31.0%, respectively, and the percentages of HQing > 0.5 for Cd in soil were 3.7% showed that V and Cd were the main factors that increased the potential non-cancer risk. Five potential sources were identified using the geostatistical and positive matrix factorization (PMF) model, among which Cd was mainly derived from the short-term weathering process of black shale (81.06%), most Zinc (Zn) was from the long-term weathering of black shale (67.35%), whereas V was contributed by many factors including long-term weathering of black shale (42.99%), traffic emissions (31.12%) and agricultural activities (21.05%). This study reveals the potential risk and identifies the sources of heavy metals, which is helpful to manage the contaminated soil in black shale mining areas.

HiPSC-derived multi-organoids-on-chip system for safety assessment of antidepressant drugs.

The poor predictive power of existing preclinical models has spurred efforts to develop human-relevant models for accurate assessment of drug safety. In this work, we developed a multi-organoids-on-a-chip system derived from human induced pluripotent stem cells (hiPSCs), which allows for the assessment of the cardiac safety of an antidepressant drug, following liver metabolism in vitro. This liver-heart organoids-on-chip device contains compartmentalized chambers separated by a porous membrane, which permits the co-culture of 3D human liver organoids in the upper multi-well chamber and cardiac organoids in the bottom micropillar array simultaneously. The co-cultured liver and heart organoids on chip maintained good viability and human organ-specific functions respectively, including the synthesis of albumin and urea of liver organoids, and the beating function of cardiac organoids. In particular, the liver organoids displayed proper metabolic capabilities with high expression of CYP450 enzyme genes. Clomipramine, a widely used antidepressant drug, can be metabolized into an active metabolite (desmethylclomipramine) through the hepatic CYP450 enzymes of liver organoids on chip identified by mass spectrometry. After exposure to 1 µM clomipramine in the liver chamber for 24 h and 48 h, the co-cultured heart organoids in the bottom layer showed significantly reduced cell viability, impaired functions of cardiac beating and calcium flux, indicating the hepatic metabolism-dependent cardiotoxicity induced by clomipramine. By combining stem cell biology and microengineered technology, this proposed hiPSC-derived multi-organoids-on-a-chip system can reflect human organ-specific functions, as well as the complex process of drug metabolism and responses at the multi-organ level. It may provide a novel platform for the assessment of drug effectiveness and safety in vitro.

Paper supported long-term 3D liver co-culture model for the assessment of hepatotoxic drugs.

Preservation of hepatic phenotype and functions in vitro has always been a great challenge for the reconstruction of liver tissue engineering and in pharmaceutical research studies. Human induced hepatocytes (hiHeps) generated from fibroblasts can be reproducible with almost normal levels of liver specific functions, which are considered as a new source of hepatocytes for biomedical applications. Moreover, paper has served as an attractive biocompatible material for cell-based applications. In this study, we established a simple paper-based scaffold array for creating a 3D liver co-culture model that enabled the assessment of drug induced hepatotoxicity. The hiHeps co-cultured with HUVECs exhibited a 3D like morphology and maintained the liver specific functions of producing albumin and urea for up to 2 months. In addition, the hiHeps in this co-cultured model maintained a higher expression of cytochrome P450 genes as compared with a monolayer culture on a plate and a single culture on paper of hiHeps, revealing a marked enhancement of hepatic functions in the 3D liver co-culture model. Moreover, the 3D liver co-culture model was exposed to acetaminophen (APAP) and pioglitazone, exhibiting near physiological hepatotoxic responses compared to those of the monolayer cultures. Taken together, the low-cost and bioactive paper scaffold could offer great opportunities as 3D in vitro platforms for tissue engineering applications and high-throughput drug testing.