1 September 2008 Macromolecular diffusion in the extracellular matrix measured by fluorescence correlation spectroscopy
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J. of Biomedical Optics, 13(5), 054040 (2008). doi:10.1117/1.2982530
Diffusion of therapeutic macromolecules through the extracellular matrix of tumor tissue is a crucial step in drug delivery. We use fluorescence correlation spectroscopy (FCS) to measure diffusion of IgG (150 kDa) and dextrans (155 kDa and 2 MDa) in solution, 5% gelatin hydrogel, and multicellular spheroids. Gel and spheroids are used as model systems for the extracellular matrix. The diffusion depends on the complexity of the environment, as well as on the size and structural shape of the diffusing molecules. The results based on one-photon FCS are in good agreement with diffusion coefficients obtained with two-photon fluorescence recovery after photobleaching (FRAP) using the same microscope (Zeiss LSM510 META/Confocor2). However, FCS reveals anomalous or multicomponent diffusion in gel and spheroids, which are not resolvable with FRAP. This study demonstrates that one-photon FCS can be used to study the extracellular transport of macromolecules in tumor tissue, and that FCS provides additional information about diffusion properties compared to FRAP.
Nina Kristine Reitan, Aphirak Juthajan, Tore Lindmo, Catharina de Lange Davies, "Macromolecular diffusion in the extracellular matrix measured by fluorescence correlation spectroscopy," Journal of Biomedical Optics 13(5), 054040 (1 September 2008). https://doi.org/10.1117/1.2982530

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