Improving sensitivity in nonlinear Raman microspectroscopy imaging and sensing.
Ontology highlight
ABSTRACT:
SUBMITTER: Arora R
PROVIDER: S-EPMC3061330 | biostudies-other | 2011 Feb
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Aortic rupture and dissection are life-threatening complications of ascending thoracic aortic aneurysms (aTAAs), and risk assessment has been largely based on the monitoring of lumen size enlargement. Temporal changes in the extracellular matrix (ECM), which has a critical impact on aortic remodeling, are not routinely evaluated, and cardiovascular biomarkers do not exist to predict aTAA formation. Here, Raman microspectroscopy and Raman imaging are used to identify spectral biomarkers specific for aTAAs in mice and humans by multivariate data analysis (MVA). Multivariate curve resolution-alternating least-squares (MCR-ALS) combined with Lasso regression reveals elastic fiber-derived (Ce1) and collagen fiber-derived (Cc6) components that are significantly increased in aTAA lesions of murine and human aortic tissues. In particular, Cc6 detects changes in amino acid residues, including phenylalanine, tyrosine, tryptophan, cysteine, aspartate, and glutamate. Ce1 and Cc6 may serve as diagnostic Raman biomarkers that detect alterations of amino acids derived from aneurysm lesions.
| S-EPMC8149374 | biostudies-literature
Project description:Bone has a sophisticated architecture characterized by a hierarchical organization, starting at the sub-micrometre level. Thus, the analysis of the mechanical and structural properties of bone at this scale is essential to understand the relationship between its physiology, physical properties and chemical composition. Here, we unveil the potential of Brillouin-Raman microspectroscopy (BRaMS), an emerging correlative optical approach that can simultaneously assess bone mechanics and chemistry with micrometric resolution. Correlative hyperspectral imaging, performed on a human diaphyseal ring, reveals a complex microarchitecture that is reflected in extremely rich and informative spectra. An innovative method for mechanical properties analysis is proposed, mapping the intermixing of soft and hard tissue areas and revealing the coexistence of regions involved in remodelling processes, nutrient transportation and structural support. The mineralized regions appear elastically inhomogeneous, resembling the pattern of the osteons' lamellae, while Raman and energy-dispersive X-ray images through scanning electron microscopy show an overall uniform distribution of the mineral content, suggesting that other structural factors are responsible for lamellar micromechanical heterogeneity. These results, besides giving an important insight into cortical bone tissue properties, highlight the potential of BRaMS to access the origin of anisotropic mechanical properties, which are almost ubiquitous in other biological tissues.
| S-EPMC8807060 | biostudies-literature
Project description:Confocal Raman microspectroscopy and fluorescence imaging are two well-established methods providing functional insight into the extracellular matrix and into living cells and tissues, respectively, down to single molecule detection. In living tissues, however, cells and extracellular matrix coexist and interact. To acquire information on this cell-matrix interaction, we developed a technique for colocalized, correlative multispectral tissue analysis by implementing high-sensitivity, wide-field fluorescence imaging on a confocal Raman microscope. As a proof of principle, we study early stages of bone formation in the zebrafish (Danio rerio) larvae because the zebrafish has emerged as a model organism to study vertebrate development. The newly formed bones were stained using a calcium fluorescent marker and the maturation process was imaged and chemically characterized in vivo. Results obtained from early stages of mineral deposition in the zebrafish fin bone unequivocally show the presence of hydrogen phosphate containing mineral phases in addition to the carbonated apatite mineral. The approach developed here opens significant opportunities in molecular imaging of metabolic activities, intracellular sensing, and trafficking as well as in vivo exploration of cell-tissue interfaces under (patho-)physiological conditions.
| S-EPMC3944822 | biostudies-literature
Project description:BackgroundOrganoids, which are organs grown in a dish from stem or progenitor cells, model the structure and function of organs and can be used to define molecular events during organ formation, model human disease, assess drug responses, and perform grafting in vivo for regenerative medicine approaches. For therapeutic applications, there is a need for nondestructive methods to identify the differentiation state of unlabeled organoids in response to treatment with growth factors or pharmacologicals.MethodsUsing complex 3D submandibular salivary gland organoids developed from embryonic progenitor cells, which respond to EGF by proliferating and FGF2 by undergoing branching morphogenesis and proacinar differentiation, we developed Raman confocal microspectroscopy methods to define Raman signatures for each of these organoid states using both fixed and live organoids.ResultsThree separate quantitative comparisons, Raman spectral features, multivariate analysis, and machine learning, classified distinct organoid differentiation signatures and revealed that the Raman spectral signatures were predictive of organoid phenotype.ConclusionsAs the organoids were unlabeled, intact, and hydrated at the time of imaging, Raman spectral fingerprints can be used to noninvasively distinguish between different organoid phenotypes for future applications in disease modeling, drug screening, and regenerative medicine.
| S-EPMC9238268 | biostudies-literature
Project description:A hallmark of Parkinson's disease (PD) is the formation of Lewy bodies in the brain. Lewy bodies are rich in the aggregated form of misfolded α-Synuclein (α-Syn). The brain from PD patients can only be analyzed after postmortem, therefore, limiting the diagnosis of PD to the manifestation of motor symptoms. In PD patients and animal models, phosphorylated α-Syn was detected in the peripheral tissues including the gut, thus, raising the hypothesis that early-stage PD could be diagnosed based on colon tissue biopsies. Non-invasive marker-free technologies represent ideal methods to potentially detect aggregated α-Syn in vivo. Raman microspectroscopy has been established for the detection of molecular changes such as alterations of protein structures. Using Raman imaging and microspectroscopy, we analyzed the olfactory bulb in the brain and the muscularis mucosae of colon tissue sections of a human BAC-SNCA transgenic (TG) rat model. Raman images from TG and WT rats were investigated using principal component analysis (PCA) and true component analysis (TCA). Spectral components indicated protein aggregates (spheroidal oligomers) in the TG rat brain and in the colon tissues even at a young age but not in WT. In summary, we have demonstrated that Raman imaging is capable of detecting α-Syn aggregates in colon tissues of a PD rat model and making it a promising tool for future use in PD pathology.
| S-EPMC8461246 | biostudies-literature
Project description:PurposeTo image SDS distribution across different skin regions, to compare the permeability difference between porcine and human skin, and to evaluate the interaction between SDS and skin.MethodsFull thickness porcine and human skin was treated with acyl chain perdeuterated SDS (SDS-d(25)) at room temperature and at 34 °C for 3, 24 and 40 h. SDS distribution in skin was monitored by confocal Raman and IR microspectroscopic imaging. Permeation profiles of SDS-d(25) in skin were derived from the band intensities of the CD(2) stretching vibrations. The interaction between SDS and skin was monitored through the CH(2) and CD(2) stretching frequencies and the Amide I and II spectral region.ResultsSDS-d(25) penetrates both porcine and human skin in a time and temperature-dependent manner, with slightly higher permeability through the stratum corneum (SC) in porcine skin. When SDS permeates into the SC, its chains are more ordered compared to SDS micelles. The secondary structure of keratin in the SC is not affected by SDS-d(25).ConclusionThe spatial distribution of SDS-d(25) in skin was obtained for the first time. Infrared microscopic imaging provides unique opportunities to measure concentration profiles of exogenous materials in skin and offers insights to interaction between permeants and skin.
| S-EPMC3399083 | biostudies-literature
Project description:Methodologies for direct intracellular imaging of RNA and DNA are necessary for the advancement of bioimaging. Here we show direct label-free imaging of RNA and DNA in single cells by isolating their accurate Raman spectra. Raman images of DNA from interphase cells show intact nucleus, while those from mitotic cells reveal condensed chromosome. The condensed chromosome images are accurate enough to assign the stage of mitotic cell division (e.g., metaphase). Raman spectral features indicate B-DNA double helical conformational form in all the cell lines investigated here. The Raman images of RNAs, on the other hand, reveal liquid-liquid phase separated (LLPS) membraneless organelles in interphase cells, which disappears during mitosis. Further, the Raman spectrum of proteins from the intracellular LLPS organelles indicates slight enrichment of amyloid-like secondary structural features. Vibrational imaging of intracellular DNA and RNA simultaneously would open myriad of opportunities for examining functional biochemical aspects of cells and organelles.
| S-EPMC9759543 | biostudies-literature
Project description:Knowledge of electrolyte transport and thermodynamic properties in Li-ion and beyond Li-ion technologies is vital for their continued development and success. Here, we present a method for fully characterising electrolyte systems. By measuring the electrolyte concentration gradient over time via operando Raman microspectroscopy, in tandem with potentiostatic electrochemical impedance spectroscopy, the Fickian "apparent" diffusion coefficient, transference number, thermodynamic factor, ionic conductivity and resistance of charge-transfer were quantified within a single experimental setup. Using lithium bis(fluorosulfonyl)imide (LiFSI) in tetraglyme (G4) as a model system, our study provides a visualisation of the electrolyte concentration gradient; a method for determining key electrolyte properties, and a necessary technique for correlating bulk intermolecular electrolyte structure with the described transport and thermodynamic properties.
| S-EPMC8245635 | biostudies-literature
Project description:Traditional in vitro anticancer drug sensitivity testing at the population level suffers from lengthy procedures and high false positive rates. To overcome these defects, we built a confocal Raman microscopy sensing system and proposed a single-cell approach via Raman-deuterium isotope probing (Raman-DIP) as a rapid and reliable in vitro drug efficacy evaluation method. Raman-DIP detected the incorporation of deuterium into the cell, which correlated with the metabolic activity of the cell. The human non-small cell lung cancer cell line HCC827 and human breast cancer cell line MCF-7 were tested against eight different anticancer drugs. The metabolic activity of cancer cells could be detected as early as 12 h, independent of cell growth. Incubation of cells in 30% heavy water (D2O) did not show any negative effect on cell viability. Compared with traditional methods, Raman-DIP could accurately determine the drug effect, meanwhile, it could reduce the testing period from 72-144 h to 48 h. Moreover, the heterogeneity of cells responding to anticancer drugs was observed at the single-cell level. This proof-of-concept study demonstrated the potential of Raman-DIP to be a reliable tool for cancer drug discovery and drug susceptibility testing.
| S-EPMC8392728 | biostudies-literature
Project description:In this report, we show the collection of spatial information through a turbid medium by coherent Raman microspectroscopic imaging. In particular, the technique is capable of identifying anthrax endospores inside a sealed paper envelope.
| S-EPMC3268280 | biostudies-literature