Morphological evaluation of apoptosis induced by salicylates in HT-1080 human fibrosarcoma cells

Biocompatible coatings based on photo-crosslinkable cellulose derivatives

Materials derived from renewable resources have great potential to replace fossil-based plastics in biomedical applications. In this study, the synthesis of cellulose-based photoresists by esterification with methacrylic acid anhydride and sorbic acid was investigated. These resists polymerize under UV irradiation in the range of λ = 254 nm to 365 nm, with or, in the case of the sorbic acid derivative, without using an additional photoinitiator. Usability for biomedical applications was demonstrated by investigating the adhesion and viability of a fibrosarcoma cell line (HT-1080). Compared to polystyrene, the material widely used for cell culture dishes, cell adhesion to the biomaterials tested was even stronger, as assessed by a centrifugation assay. Remarkably, chemical surface modifications of cellulose acetate with methacrylate and sorbic acid allow direct attachment of HT-1080 cells without adding protein modifiers or ligands. Furthermore, cells on both biomaterials show similar cell viability, not significantly different from polystyrene, indicating no significant impairment or enhancement, allowing the use of these cellulose derivatives as support structures for scaffolds or as a self-supporting coating for cell culture solely based on renewable resources.

Imaging modification of colon carcinoma cells exposed to lipid based nanovectors for drug delivery: a scanning electron microscopy investigation

The adsorption at cell surfaces and cell internalization of two drug delivery lipid based nanovectors has been investigated by means of Field Emission Scanning Electron Microscopy (FE-SEM) operating at low beam voltage on two different colon carcinoma cell lines, CaCo-2 and CoLo-205, that were compared with the M14 melanoma cell line, as a reference. The cells were incubated with the investigated multifunctional nanovectors, based on liposomes and magnetic micelles loaded with 5-fluorouracil, as a chemotherapeutic agent, and a FE-SEM systematic investigation was performed, enabling a detailed imaging of any morphological changes of the drug exposed cells as a function of time. The results of the FE-SEM investigation were validated by MTS assay and immunofluorescence staining of the Ki-67 protein performed on the investigated cell lines at different times. The two nanoformulations resulted in a comparable effect on CaCo-2 and M14 cell lines, while for CoLo 205 cells, the liposomes provided an cytotoxic activity higher than that observed in the case of the micelles. The study highlighted the high potential of FE-SEM as a valuable complementary technique for imaging and monitoring in time the drug effects on the selected cells exposed to the two different nanoformulations.

Measuring systematic changes in invasive cancer cell shape using Zernike moments

We study the shape characteristics of osteosarcoma cancer cell lines on surfaces of differing hydrophobicity using Zernike moments to represent cell shape. We compare the shape characteristics of four invasive cell lines with a corresponding less-invasive parental line on three substrates. Cell shapes of each pair of cell lines are quite close and display overlapping characteristics. To quantitatively study shape changes in high-dimensional parameter space we project down to principal component space and define a vector that summarizes average shape differences. Using this vector we find that three of the four pairs of cell lines show similar changes in shape, while the fourth pair shows a very different pattern of changes. We find that shape differences are sufficient to enable a neural network to classify cells accurately as belonging to the highly invasive or the less invasive phenotype. The patterns of shape changes were also reproducible for repetitions of the experiment. We also find that shape changes on different substrates show similarities between the eight cells studied, but the differences were typically not enough to permit classification. Our paper strongly suggests that shape may provide a means to read out the phenotypic state of some cell types, and shape analysis can be usefully performed using a Zernike moment representation.

Multimodal holographic microscopy: distinction between apoptosis and oncosis

Identification of specific cell death is of a great value for many scientists. Predominant types of cell death can be detected by flow-cytometry (FCM). Nevertheless, the absence of cellular morphology analysis leads to the misclassification of cell death type due to underestimated oncosis. However, the definition of the oncosis is important because of its potential reversibility. Therefore, FCM analysis of cell death using annexin V/propidium iodide assay was compared with holographic microscopy coupled with fluorescence detection - “Multimodal holographic microscopy (MHM)”. The aim was to highlight FCM limitations and to point out MHM advantages. It was shown that the annexin V+/PI− phenotype is not specific of early apoptotic cells, as previously believed, and that morphological criteria have to be necessarily combined with annexin V/PI for the cell death type to be ascertained precisely. MHM makes it possible to distinguish oncosis clearly from apoptosis and to stratify the progression of oncosis.