Search for: All records

Metabolites are critical products and mediators of cellular and tissue function, and key signals in cell-to-cell, organ-to-organ and cross-organism communication. Many of these interactions are spatially segregated. Thus, spatial metabolomics can provide valuable insight into healthy tissue function and disease pathogenesis. Here, we review major mass spectrometry-based spatial metabolomics techniques and the biological insights they have enabled, with a focus on brain and microbiota function and on cancer, neurological diseases and infectious diseases. These techniques also present significant translational utility, for example in cancer diagnosis, and for drug development. However, spatial mass spectrometry techniques still encounter significant challenges, including artifactual features, metabolite annotation, open data, and ethical considerations. Addressing these issues represent the future challenges in this field. 

Abstract: Colloidal all‐inorganic lead halide perovskite quantum dots (QDs) are high‐performance light‐emitting materials with size‐dependent optical properties and can be readily synthesized by mixing ionic precursors. However, the low formation energy of the perovskite lattice makes their growth too fast to control under regular reaction conditions. Diffusion‐regulated CsPbBr3 perovskite QD growth is reported on a nanometer‐sized liquid/liquid (L/L) interface supported in a micropipette tip without long‐chain organic ligands. The precursors are divided into two immiscible solutions across the L/L interface to avoid additional nucleation, and the QD growth kinetics are regulated by the constrained cationic diffusion field depending on the size of the micropipette tip. QDs with unprecedentedly small sizes (2.7 nm) are obtained due to the slowed‐down growth rates. The synthesis approach demonstrates the potential of micro‐controlled colloidal QD synthesis for mechanistic studies and micro‐fabrications. 

Nitric oxide (NO) is a small molecule that plays important roles in biological systems and human diseases. The abundance of intracellular NO is tightly related to numerous biological processes. Due to cell heterogeneity, the intracellular NO amounts significantly vary from cell to cell, and therefore, any meaningful studies need to be conducted at the single-cell level. However, measuring NO in single cells is very challenging, primarily due to the extremely small size of single cells and reactive nature of NO. In the current studies, the quantitative reaction between NO and amlodipine, a compound containing the Hantzsch ester group, was performed in live cells. The product dehydro amlodipine was then detected by the Single-probe single-cell mass spectrometry technique to quantify NO in single cells. The experimental results indicated heterogeneous distributions of intracellular NO amounts in single cells with the existence of subpopulations.