Label-free 3D molecular imaging of living tissues using Raman spectral projection tomography.

The ability to image tissues in three dimensions (3D) with label-free molecular contrast at the mesoscale would be a valuable capability in biology and biomedicine. Here, we introduce Raman spectral projection tomography (RSPT) for volumetric molecular imaging with optical sub-millimeter spatial resolution. We have developed a RSPT imaging instrument capable of providing 3D molecular contrast in transparent and semi-transparent samples.

Opto-Lipidomics of Tissues.

Lipid metabolism and signaling play pivotal functions in biology and disease development. Despite this, currently available optical techniques are limited in their ability to directly visualize the lipidome in tissues. In this study, opto-lipidomics, a new approach to optical molecular tissue imaging is introduced.

Longitudinal Monitoring of Disease Progression in Inflammatory Arthritis Animal Models Using Raman Spectroscopy.

Current techniques for monitoring disease progression and testing drug efficacy in animal models of inflammatory arthritis are either destructive, time-consuming, subjective, or require ionizing radiation. To accommodate this, we have developed a non-invasive and label-free optical system based on Raman spectroscopy for monitoring tissue alterations in rodent models of arthritis at the biomolecular level. To test different sampling geometries, the system was designed to collect both transmission and reflection mode spectra.

6-Color/1-Target Immuno-SERS Microscopy on the Same Single Cancer Cell.

There is an urgent clinical need for multicolor imaging of single cancer cells (no ensemble averaging) for identifying heterogenous expression of predictive biomarkers. Specifically, the comprehensive characterization of single disseminated tumor cells (sDTCs) responsible for metastatic relapse is the key to personalized therapy for patients. Current bioimaging methods lack the necessary multicolor capacity and suffer from background/autofluorescence.

Localization of PD-L1 on single cancer cells by iSERS microscopy with Au/Au core/satellite nanoparticles.

Programmed cell death-ligand 1 (PD-L1) is an important predictive biomarker. The detection of PD-L1 can be crucial for patients with advanced cancer where the use of immunotherapy is considered. Here, we demonstrate the use of immuno-SERS microscopy (iSERS) for localizing PD-L1 on single cancer SkBr-3 cells.

ImmunoSERS microscopy for the detection of smooth muscle cells in atherosclerotic plaques.

We investigated the suitability of immuno-SERS (iSERS) microscopy for imaging of smooth muscle cells (SMCs) in atherosclerotic plaques. Localization of SMCs is achieved by using SERS-labelled antibodies direct against alpha-smooth muscle actin (SMA). The staining quality of the false-colour iSERS images obtained by confocal Raman microscopy with point mapping is compared with wide-field immunofluorescence images.

Evaluation of 3D gold nanodendrite layers obtained by templated galvanic displacement reactions for SERS sensing and heterogeneous catalysis.

Dense layers of overlapping three-dimensional (3D) gold nanodendrites characterized by high specific surfaces as well as by abundance of sharp edges and vertices creating high densities of SERS hotspots are promising substrates for SERS-based sensing and catalysis. We have evaluated to what extent structural features of 3D gold nanodendrite layers can be optimized by the initiation of 3D gold nanodendrite growth at gold particles rationally positioned on silicon wafers. For this purpose, galvanic displacement reactions yielding 3D gold nanodendrites were guided by hexagonal arrays of parent gold particles with a lattice constant of 1.