Now showing 1 - 3 of 3
  • Publication
    Evaluation of cell behaviour on atmospheric plasma deposited siloxane and fluorosiloxane coatings
    For developing functional biomaterials, an understanding of the biological response at material surfaces is of key importance. In particular, surface chemistry, roughness and cell type influence this response. Many previous reports in the literature have involved the study of single cell types and their adhesion to surfaces with a limited range of water contact angles. The objective of this study was to investigate the adhesion of five cell lines on surfaces with contact angles in the range of 20 to 115 . This range of water contact angles was obtained using siloxane and fluorosiloxane coatings deposited using atmospheric plasma deposition. These nm thick coatings were deposited by nebulizing liquid precursors consisting of poly(dimethylsiloxane) (PDMS) and a mixture of perfluorodecyl acrylate/ tetraethylorthosilicate (PPFDA/TEOS) into the atmospheric plasmas. Cell adhesion studies were carried out with the following cell types: Osteoblast, Human Embryonic Kidney (HEK), Chinese hamster ovary (CHO), Hepatocytes (HepZ) and THP1 leukemic cells. The study demonstrated that cell adhesion was significantly influenced by the type of cell line, water contact angle and coating chemistry. For example the sensitivity of cell lines to changes in contact angle was found to decrease in the following order: Osteoblasts >Hepatocytes> CHO. The HEK and THP-1 inflammatory cells in contrast were not found to be sensitive to changes in water contact angle.
      493Scopus© Citations 10
  • Publication
    Nanoscale infrared absorption imaging permits non-destructive intracellular photosensitizer localization for subcellular uptake analysis
    The most immediate biological and medical advantages of therapeutic agent localization on the nanoscale arise from the increased understanding of targeted delivery, selectivity and intracellular distribution that are gained by imaging at the resolution scale of individual nanovectors and therapeutic agents themselves. This paper reports on the use of a nanoscale resolution chemical imaging method, infrared (IR) nanospectral absorption imaging, used to map the subcellular localization of a photoactive therapeutic agent - toluidine blue-conjugated gold nanoparticles (TBO) within nanoscale subsections of single colon adenocarcinoma cells. By comparison of photosensitizer distribution with diffraction limited optical imaging, the benefits of IR nanospectral localization are highlighted and the spatial and spectral accuracy of the non-destructive IR imaging method is confirmed. IR spectral ratio imaging is presented as a means to map intracellular nanoparticle density at sub 50 nm lateral resolution with IR nanospectroscopy enabling distinction of nanoparticle seeded cells from a control group with 95% confidence. In this way we illustrate that IR absorption nanoimaging combined with IR point source data does not only yield intracellular drug detection on the order of nanometres, but also permits extension of the AFM-IR technique from subcellular analysis up to studies of cell numbers that are statistically significant.
      365Scopus© Citations 28
  • Publication
    Quantifying nanoscale biochemical heterogeneity in human epithelial cancer cells using combined AFM and PTIR absorption nanoimaging
    Subcellular chemical heterogeneity plays a key role in cell organization and function. However the biomechanics underlying the structure-function relationship is governed by cell substructures which are poorly resolved using conventional chemical imaging methods. To date, advances in sub-diffraction limited infrared (IR) nanoscopy have permitted intracellular chemical mapping. In this work we report how image analysis applied to a combination of IR absorption nanoimaging and topographic data permits quantification of chemical complexity at the nanoscale, enabling the analysis of biochemical heterogeneity in mammalian cancer cells on the scale of subcellular features.
      373Scopus© Citations 23