ECM degradation in DED organotypic cultures by collagenase treatment. Immunofluorescence staining for Krt14 (green), Ki67 (red) and Vimentin (white) of DED organotypic cultures at indicated time points after collagenase treatment. Quantification of Ki67 positive fibroblasts at indicated time point after collagenase treatment (n= 8 section per condition of one representative experiment repeated two times). Note that fibroblasts around the injection sides start to proliferate after 48 hours. Nuclei were labelled with DAPI (blue) (D,F). Scale bars, 100µm (D,F). Data shown are means ± s.d. Fb, fibroblasts; PD, post digestion; TCP, tissue culture plastic; h, hours. 