Three‐dimensional printed microfluidic mixer/extractor for cell lysis and lipidomic profiling by matrix‐assisted laser desorption/ionization mass spectrometry

Abstract

Lipidomic profiling has been linked to the detection of cancers as dysregulation of lipid metabolism is closely associated with many disease states. Current work on chip‐based profiling has been limited and is largely hindered by issues associated with the chip's sophisticated fabrication processes. We report here the design and fabrication of a highly efficient microfluidic mixer/extractor by using three‐dimensional (3D) printing technology for on‐chip cell lysis/enrichment for lipidomic profiling with matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS). The platform consists of a micropillar mixer for flow‐through lysis and an on‐chip reservoir to separate phases where the lipid‐enriched layer was collected for subsequent MS analysis. The mass transfer between the two phases was simulated by a computational fluid dynamics study, and the efficiency in cell lysis in different extraction solvent systems was characterized by fluorescence microscopy. Results showed increased performance in extraction with the micropillar mixer as compared with the standard Bligh‐Dyer method. For lipid profiling of C. reinhardtii cells by MALDI‐MS, over 65 lipid species from the monogalactosyldiacylglycerol, digalactosyldiacylglycerol, diacylglyceryltrimethylhomo‐Ser, and triacylglycerol lipid families have been identified. The effect of organic solvents on extraction and lipid profiles was also investigated, and the results indicated that the extractant formula has a diverse impact on the collection of certain types of lipid species, presenting useful guidance for the system to be applied to targeted enrichment of lipids with specific cells. The microfluidic chips by the 3D printing technique reported here offer new platforms potentially for clinical lipidomics and can provide a novel avenue in disease diagnosis.

Quantitative mass spectrometry imaging: therapeutics & biomolecules

“…Lastly, for both MALDI and DESI studies, the field of fluidics has emerged for MS analysis of biomolecules at the subcellular level and displays great promise for increasing the sensitivity of molecular targets. 116,117 Incorporation of fluidics to MS is very compelling for applications dealing with small sample sizes, increasing analyte sensitivity, and the potential addition to MSI workflows. 118…”

Microfluidics Coupled Mass Spectrometry for Single Cell Multi‐Omics

“…Lipids play an important role in various biological functions, such as cellular membrane formation, regulating gene expression, membrane transport, bioactive inter-and intracellular signaling, as well as energy storage. [114,115] Lipids undergo changes during cell differentiation and vary from cell to cell. Similar with singlecell metabolomic analysis, single-cell lipidome can also be analyzed using capillary ESI-MS, as well as microarrays coupled with MALDI MS. MALDI MS can detect hundreds of lipid molecules with high resolution and accuracy.…”

Plasmonic Alloys Enhanced Metabolic Fingerprints for the Diagnosis of COPD and Exacerbations

“…Biomarkers allow the characterization of disease progression at the molecular level through noninvasive techniques, , holding promise for the diagnosis of COPD and exacerbations. ,, Recently, various gene (e.g., circulating miRNA) , and protein biomarkers (e.g., C-reactive protein) , have been reported for the diagnosis or evaluation of COPD, but their performance is suboptimal for clinical use due to their poor accuracy . Compared with genes and proteins, metabolites function as immediate indicators of biochemical activity and exhibit a close correlation with the COPD phenotype. , Mass spectrometry (MS), specifically laser desorption/ionization (LDI) MS, has emerged as a robust analytical instrument for the high-throughput and sensitive detection of various metabolites. − However, metabolic analysis is often impeded by the inherent challenges of concentration and purification, given the low concentration of metabolites and high complexity of samples in clinical specimens. ,− …”