Figure 4

Drug diffusion evaluation. (A) Thickness (µm) of a 3DT. (B) Doxorubicin (doxo; red) diffusion assay in 3DT, repopulated with HT29 ZSgreen positive cells (green). In the enlargement, the same fixed samples were evaluated with immunofluorescence to underline the co-localization between drug (doxo) and nuclei (DAPI). Absence of non-specific binding between doxo and extracellular matrix (ECM) (scale bar = 100 µm). (C) Quantification of co-localized signals. (D) In-house developed permeability device. (E) Experimental results of the filtration process carried out on the tumor colon fresh, 3DT, and decellularized (decell). Open circles refer to the experimental values, and solid black lines to the Equation (2) fitted to experimental data, and the charts report the estimated values of permeability K (mm4/Ns). (F) Quantification of permeability measurement obtained from fresh, 3DT, and decellularized (decell) tumor samples. (* p-value < 0.05; ** p-value < 0.01; *** p-value < 0.001).