Acute myeloid leukemia (AML) is a malignant hematological tumor disease. Chromosomal abnormality is an independent prognostic factor in AML. AML with t(8:21) (q22; q22)/AML1-ETO (AE) is an independent disease group. In this research, a new method based on Raman spectroscopy is reported for label-free single-cell identification and analysis of AE fusion genes in clinical AML patients. Raman spectroscopy reflects the intrinsic vibration information of molecules in a label-free and non-destructive manner, and the fingerprint Raman spectrum of cells characterizes intracellular molecular types and relative concentration information, so as to realize the identification and molecular metabolism analysis of different kinds of cells. We collected the Raman spectra of bone marrow cells from clinically diagnosed AML M2 patients with and without the AE fusion gene. Through comparison of the average spectra and identification analysis based on multivariate statistical methods such as principal component analysis and linear discriminant analysis, the distinction between AE positive and negative sample cells in M2 AML patients was successfully achieved, and the single-cell identification accuracy was more than 90%. At the same time, the Raman spectra of the two types of cells were analyzed by the multivariate curve resolution alternating least squares decomposition method. It was found that the presence of the AE fusion gene may lead to the metabolic changes of lipid and nucleic acid in AML cells, which was consistent with the results of genomic and metabolomic multi-omics studies. The above results indicate that single-cell Raman spectroscopy has the potential for early identification of AE-positive AML.

As a label-free, nondestructive, and in situ detection method, Raman spectroscopy analysis of single cells has potential application value in biomedical fields such as cancer diagnosis. In this study, the Raman spectral characteristics of nucleophosmin (NPM1)-mutant acute myeloid leukemia (AML) cells and nonmutated AML cells were investigated, and the reasons for the differences in spectral peaks were explained in combination with transcriptomic analysis. Raman spectra of two AML cell lines without NPM1 mutation (THP-1 and HL-60) and the OCI-AML3 cell line carrying the NPM1 mutant gene were cultured and collected experimentally. It was found that the average Raman spectra of NPM1 mutant and nonmutated cells had intensity differences in multiple peaks corresponding to chondroitin sulfate (CS), nucleic acid, protein, and other molecules. The differentially expressed genes were identified by quantitative analysis of the gene expression matrix of the two types of cells, and their roles in the regulation of CS proteoglycan and protein synthesis were analyzed. The results showed that the differences between the two types of cells expressed by the single-cell Raman spectral information were consistent with the differences in transcriptional profiles. This research could advance the application of Raman spectroscopy in cancer cell typing.

As a kind of special paper artifact, memorials are considered physical evidence that embody the emperors culture, of which the paper-making and dyeing process reflect the political culture and social development level of the Qing Dynasty. The composing materials of the memorial are fragile. Previous research on memorials have mainly focused on text content, style, political influence and restoration, while the analysis towards the original materials and crafts is relatively scarce. By employing various in situ non-destructive techniques, a systematical study has been conducted on the paper-making and dyeing process of a memorial from Cen Chunxuan, an important minister in the late Qing Dynasty. UV fluorescence photography and FTIR spectra showed that the yellow damask-decorated patterns on the folding page and envelope were woven with silk products. Comprehensive analysis results of ultra-depth-of-field microscopic observation, Raman spectroscopy and XRF demonstrated that the mineral pigment Orpiment with a pretty fine graininess was used to dye the memorial paper through the brush dyeing method. Orpiment is more expensive than organic dyes such as Phellodendron amurense, which not only raises the ability of moth and water resistance but also highlights the significance of memorials in the Qing Dynastys institutional culture. It is another discovery in the case of paper dyeing yellowing. In addition, this article also explored the application of optical fiber fluorescence spectroscopy to analyze the pigment of comments written in red on the memorial and found that the red handwriting was written in cinnabar, which was consistent with the results of Raman spectroscopy and XRF. The investigation of the materials and crafts of such paper artifacts as memorials promotes the understanding of the technical characteristics of the paper-making and dyeing process in the Qing Dynasty. It provides the scientific basis for the rational protection and restoration of such cultural relics. At the same time, this article also discussed the applicability of fiber optic fluorescence spectroscopy in identifying pigments used in paper artifacts, which further expanded the types and applications of non-destructive analysis techniques.

Acute myeloid leukemia (AML) is a malignant clonal blood disease of hematopoietic stem cells with poor prognosis. Traditional diagnosis of AML depends on the morphology, immunology, cytogenetics, and molecular biology (MICM) classification. As a rapid, label-free and non-destructive detection method, Raman spectroscopy can characterize the molecular information in the biochemical process at the molecular level through peak position, intensity and other information. In this paper, we collected leukemic blast cells from 19 AML patients. Firstly, it was proved that with the help of multivariate analysis methods such as principal component analysis-linear discriminant analysis (PCA-LDA) and multivariate curve resolution-alternating least squares (MCR-ALS), Raman spectroscopy could effectively distinguish AML cells from normal leukocytes, and the accuracy rate was up to 96.71%. The results showed that compared with normal leukocytes, multiple components of information decomposed by the AML spectrum represented abnormal alterations in proteins, nucleic acids, lipids and carbohydrates in leukemia cells. Secondly, the same procedure was used to further detect different types of AML and found that Raman spectroscopy could distinguish AML cells with FMS-like tyrosine kinase 3-Internal Tandem Duplications (FLT3-ITD) mutations or not, and there were differences in spectral characteristics corresponding to nucleic acids and proteins (amino acids). The above results revealed that Raman spectroscopy has great potential for clinical diagnosis and mechanistic study of AML.

High performance sorting of circulating tumor cells (CTCs) from peripheral blood is key to liquid biopsies. Size-based deterministic lateral displacement (DLD) technique is widely used in cell sorting. But conventional microcolumns have poor fluid regulation ability, which limits the sorting performance of DLD. When the size difference between CTCs and leukocytes is small (e.g., less than 3 μm), not only DLD, many size-based separation techniques fail due to low specificity. CTCs have been confirmed to be softer than leukocytes, which could serve as a basis for sorting. In this study, we presented a multistage microfluidic CTCs sorting method, first sorting CTCs using a size-based two-array DLD chip, then purifying CTCs mixed by leukocytes using a stiffness-based cone channel chip, and finally identifying cell types using Raman techniques. The entire CTCs sorting and analysis process was label free, highly pure, high-throughput and efficient. The two-array DLD chip employed a droplet-shaped microcolumn (DMC) developed by optimization design rather than empirical design. Attributed to the excellent fluid regulation capability of DMC, the CTCs sorter system developed by parallelizing four DMC two-array DLD chips was able to process a sample of 2.5 mL per minute with a recovery efficiency of 96.30 ± 2.10% and a purity of 98.25 ± 2.48%. To isolate CTCs mixed dimensionally by leukocytes, a cone channel sorting method and chip were developed based on solid and hydrodynamic coupled analysis. The cone channel chip allowed CTCs to pass through the channel and entrap leukocytes, improving the purity of CTCs mixed by leukocytes by 1.8-fold.

Ongoing studies have determined that the gut microbiota is a major factor influencing both health and disease. Host genetic factors and environmental factors contribute to differences in gut microbiota composition and function. Intestinal dysbiosis is a cause or a contributory cause for diseases in multiple body systems, ranging from the digestive system to the immune, cardiovascular, respiratory, and even nervous system. Investigation of pathogenesis has identified specific species or strains, bacterial genes, and metabolites that play roles in certain diseases and represent potential drug targets. As research progresses, gut microbiome-based diagnosis and therapy are proposed and applied, which might lead to considerable progress in precision medicine. We further discuss the limitations of current studies and potential solutions.

Circulating tumor cells (CTCs) are cancer cells that shed from a primary tumor and circulate in the bloodstream.As a form of "tumor liquid biopsy", CTCs provide important information for the mechanistic investigation of cancer metastasis and the measurement of tumor genotype evolution during treatment and disease progression.However, the extremely low abundance of CTCs in the peripheral blood and the heterogeneity of CTCs make their isolation and characterization major technological challenges.Recently, nanotechnologies have been developed for sensitive CTC detection; such technologies will enable better cell and molecular characterization and open up a wide range of clinical applications, including early disease detection and evaluation of treatment response and disease progression.In this review, we summarize the nanotechnology-based strategies for CTC isolation, including representative nanomaterials (such as magnetic nanoparticles, gold nanoparticles, silicon nanopillars, nanowires, nanopillars, carbon nanotubes, dendrimers, quantum dots, and graphene oxide) and microfluidic chip technologies that incorporate nanoroughened surfaces and discuss their key challenges and perspectives in CTC downstream analyses, such as protein expression and genetic mutations that may reflect tumor aggressiveness and patient outcome.