Comparative assessment of detergent-based protocols for mouse lung de-cellularization and re-cellularization

Several different detergent-based methods are currently being explored for de-cellularizing whole lungs for subsequent use as three-dimensional scaffolds for ex vivo lung tissue generation. However, it is not yet clear which of these methods may provide a scaffold that best supports re-cellularization and generation of functional lung tissue. Notably, the detergents used for de-cellularization activate matrix metalloproteinases that can potentially degrade extracellular matrix (ECM) proteins important for subsequent binding and growth of cells inoculated into the de-cellularized scaffolds. We assessed gelatinase activation and the histologic appearance, protein composition, and lung mechanics of the end product scaffolds produced with three different detergent-based de-cellularization methods utilizing either Triton-X 100/sodium deoxycholate (Triton/SDC), sodium dodecyl sulfate (SDS), or 3-[(3- cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). There were significant differences both in gelatinase activation and in the retention of ECM and other intracellular proteins, assessed by immunohistochemistry, mass spectrometry, and western blotting as well as in airways resistance and elastance of lungs de-cellularized with the different methods. However, despite these differences, binding and initial growth following intratracheal inoculation with either bone marrow-derived mesenchymal stromal cells or with C10 mouse lung epithelial cells was similar between lungs de-cellularized with each method. Therefore despite differences in the structural composition of the de-cellularized lungs, initial re-cellularization does not appear significantly different between the three de-cellularization approaches studied.