Optical Diffraction Tomography and Raman Confocal Microscopy for the Investigation of Vacuoles Associated with Cancer Senescent Engulfing Cells.

Wild-type p53 cancer therapy-induced senescent cells frequently engulf and degrade neighboring ones inside a massive vacuole in their cytoplasm. After clearance of the internalized cell, the vacuole persists, seemingly empty, for several hours. Despite large vacuoles being associated with cell death, this process is known to confer a survival advantage to cancer engulfing cells, leading to therapy resistance and tumor relapse. Previous attempts to resolve the vacuolar structure and visualize their content using dyes were unsatisfying for lack of known targets and ineffective dye penetration and/or retention. Here, we overcame this problem by applying optical diffraction tomography and Raman spectroscopy to MCF7 doxorubicin-induced engulfing cells. We demonstrated a real ability of cell tomography and Raman to phenotype complex microstructures, such as cell-in-cells and vacuoles, and detect chemical species in extremely low concentrations within live cells in a completely label-free fashion. We show that vacuoles had a density indistinguishable to the medium, but were not empty, instead contained diluted cell-derived macromolecules, and we could discern vacuoles from medium and cells using their Raman fingerprint. Our approach is useful for the noninvasive investigation of senescent engulfing (and other peculiar) cells in unperturbed conditions, crucial for a better understanding of complex biological processes.

New method for bacterial load measurement during hydro-debridement of cutaneous ulcer.

AIM OF THE STUDY: Based on their experience using Versajet for debridement of chronic wounds, the Authors set up a study protocol to verify whether the hydro-surgical cleansing could offer the possibility of taking tissue specimens suitable for diagnostic microbiological evaluation. The aims of the study were the following: MAIN PURPOSE: To evaluate the efficacy of hydro-surgery in detecting the presence of microorganisms and measuring their load, as an alternative to conventional tissue sampling methods; SECONDARY PURPOSE: To set up an easier and less invasive diagnostic modality than surgical biopsy, even though likewise significant. RESULTS: The results of this study show that tissue specimen collection by hydro-aspiration using Versajet is comparable to biopsy sampling (and in some cases it can be even more reliable); moreover, it is not more time-consuming and is certainly less invasive. Compared to surgical biopsy, with such a method a greater amount of tissue may be collected; moreover, tissue specimens can be taken from a broader surface or, depending on the needs, from a more focused area on the margin or at the bottom of the wound.