Zinc-protoporphyrin determination by HPLC with fluorescence detection as a biomarker of lead effect in artisanal pottery workers

Evaluation of the potential use of protoporphyrins as biomarkers of anemic disease in human urine from inflammatory bowel disease patients

Protoporphyrins are organic compounds with cyclic structure that are synthesised by a wide variety of organisms. In humans, these compounds are detected in blood and urine, with significantly higher levels in blood. Their potential as biomarkers of anemia and other diseases is currently being investigated, as their levels change according to the biochemical processes associated with the disease. The most widely used biomarker of anemia is serum ferritin, but it is unreliable in patients with inflammatory bowel disease (IBD) because its levels can be altered by acute inflammation and/or infections. There is therefore a need to look for new markers to help diagnose anemia in IBD patients. This work develops and validates a method for the determination of three protoporphyrins in human urine: protoporphyrin IX (PPIX), protoporphyrin IX complex with Zn (ZnPPIX) and protoporphyrin IX complex with Fe (II) (FePPIX), the latter also known as heme. The aim is to evaluate their potential as biomarkers of anemic disease in patients diagnosed with IBD. The proposed analytical method is based on high performance liquid chromatography (HPLC) with dual detection based on photodiode array (PDA) and fluorescence (FD). Quantification of the analytes at very low concentrations is possible due to the efficient preconcentration provided by dispersive liquid-liquid microextraction (DLLME) and the sensitivity of the detection systems. The method was validated by evaluating linearity (25-1000 ng mL-1), matrix effect, sensitivity (limits of quantification were between 5 and 11 ng mL-1), selectivity, accuracy, carry-over, dilution integrity, stability and precision (< 12.1 %). Finally, statistical analyses applied to the sample quantification results showed these three markers, together with five clinical markers, were significantly different between anemic and non-anemic IBD patients.

Applications of 3D organoids in toxicological studies: a comprehensive analysis based on bibliometrics and advances in toxicological mechanisms

A mechanism exploration is an important part of toxicological studies. However, traditional cell and animal models can no longer meet the current needs for in-depth studies of toxicological mechanisms. The three-dimensional (3D) organoid derived from human embryonic stem cells (hESC) or induced pluripotent stem cells (hiPSC) is an ideal experimental model for the study of toxicological effects and mechanisms, which further recapitulates the human tissue microenvironment and provides a reliable method for studying complex cell-cell interactions. This article provides a comprehensive overview of the state of the 3D organoid technology in toxicological studies, including a bibliometric analysis of the existing literature and an exploration of the latest advances in toxicological mechanisms. The use of 3D organoids in toxicology research is growing rapidly, with applications in disease modeling, organ-on-chips, and drug toxicity screening being emphasized, but academic communications among countries/regions, institutions, and research scholars need to be further strengthened. Attempts to study the toxicological mechanisms of exogenous chemicals such as heavy metals, nanoparticles, drugs and organic pollutants are also increasing. It can be expected that 3D organoids can be better applied to the safety evaluation of exogenous chemicals by establishing a standardized methodology.

Detection of Pb2+ in Tea Using Aptamer Labeled with AIEgen Nanospheres Based on MOFs Sensors

Tea is an important economic crop and health beverage in China. The presence of heavy metal ions in tea poses a significant threat to public health. Here, we prepared an aptamer biosensor labelled with AIEgen nanospheres to detect Pb²⁺ in tea. The dsDNA modified by amino and phosphoric acid was combined with the carboxylated AIEgen NPs to form AIEgen-DNA with a fluorescence group, which was then fixed to the surface of Zr-MOFs to quench the fluorescence of AIEgen NPs. At the same time, PEG was added to remove nonspecific adsorption. Then Pb²⁺ was added to cut the DNA sequences containing the cutting sites, and AIEgen NPs and part of the DNA sequences were separated from the Zr-MOFs surface to recover the fluorescence. By comparing the fluorescence changes before and after adding Pb²⁺, the detection limit of Pb²⁺ can reach 1.70 nM. The fluorescence sensor was applied to detect Pb²⁺ in tea, and the detection results showed that the tea purchased on the market did not contain the concentration of Pb²⁺ within the detection range. This study provides new insights into monitoring food and agriculture-related pollutants based on fluorescent biosensors.