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Metabolic dysregulation is a key driver of cellular senescence, contributing to the progression of systemic aging. The heterogeneity of senescent cells and their metabolic shifts are complex and unexplored. A microfluidic SlipChip integrated with surface‐enhanced Raman spectroscopy (SERS), termed SlipChip‐SERS, is developed for single‐cell metabolism analysis. This SlipChip‐SERS enables compartmentalization of single cells, parallel delivery of saponin and nanoparticles to release intracellular metabolites and to realize SERS detection with simple slipping operations. Analysis of different cancer cell lines using SlipChip‐SERS demonstrated its capability for sensitive and multiplexed metabolic profiling of individual cells. When applied to human primary fibroblasts of different ages, it identified 12 differential metabolites, with spermine validated as a potent inducer of cellular senescence. Prolonged exposure to spermine can induce a classic senescence phenotype, such as increased senescence‐associated β‐glactosidase activity, elevated expression of senescence‐related genes and reduced LMNB1 levels. Additionally, the senescence‐inducing capacity of spermine in HUVECs and WRL‐68 cells is confirmed, and exogenous spermine treatment increased the accumulation and release of H2O2. Overall, a novel SlipChip‐SERS system is developed for single‐cell metabolic analysis, revealing spermine as a potential inducer of senescence across multiple cell types, which may offer new strategies for addressing ageing and ageing‐related diseases. [ABSTRACT FROM AUTHOR]

We calculated the area of seven ecosystems, used the NDVI index to analyze the temporal-change of vegetation-covered land in the Qinghai Lake basin from 2004 to 2019, and the principal component analysis to analyze the driving mechanism of desertification. The results showed that grasslands are the dominant ecosystem, and the desert ecosystem had an area of 32 km2, accounting for only 0.1% of the total area. The evolution of desertification was in the reversal stage. The vegetation cover increased from 54% in 2004 to 66% in 2019, showing a change process of mild destruction-slow restoration: 2004-2008, high degree vegetation-covered land dominated the declination of vegetation with the dynamic trend of -5.67%; 2009-2013, medium degree vegetation-covered land dominated the restoration of vegetation with the dynamic trend of 2.45%; 2014-2019, medium and high degree vegetation-covered land showed an increasing trend with the dynamic trend of 0.86% and 1.17% respectively. Natural and human factors, which were manifested as the domination of human activities and the exacerbation effect of natural factors, influenced desertification. The first principal component integrated both anthropogenic and natural factors accounted for 52.27% of the contribution rate, while the second principal component included only natural factors that accounted for 23.77%.

Bioorthogonal drug molecules are currently gaining prominence for their excellent efficacy, safety and metabolic stability. Pharmacokinetic study is critical for understanding their mechanisms and guiding pharmacotherapy, which is primarily performed with liquid chromatography-mass spectrometry as the gold standard. For broader and more efficient applications in clinics and fundamental research, further advancements are especially desired in cheap and portable instrumentation as well as rapid and tractable pretreatment procedures. Surface-enhanced Raman spectroscopy (SERS) is capable of label-free detection of various molecules based on the spectral signatures with high sensitivity even down to a single-molecule level. But limited by irreproducibility at low concentrations and spectral interference in complex biofluids, SERS hasn't been widely applied for pharmacokinetics, especially in live animals. In this work, we propose a new method to quantify bioorthogonal drug molecules with signatures at the spectral silent region (SR) by the digital colloid-enhanced Raman spectroscopy (dCERS) technique. This method was first validated using 4-mercaptobenzonitrile in a mixture of analogous molecules, exhibiting reliable and specific identification capability based on the unique SR signature and Poisson-determined quantification accuracy. We further developed a single-step serum pretreatment method and successfully profiled the pharmacokinetic behavior of an anticancer drug, erlotinib, from animal studies. In a word, this method, superior in sensitivity, controllable accuracy, minimal background interference and facile pretreatment and measurement, promises diverse applications in fundamental studies and clinical tests of bioorthogonal drug molecules., Competing Interests: The authors declare no conflicts of interest., (This journal is © The Royal Society of Chemistry.)