Updated project metadata. Tissue engeneering using biological scaffolds are a promising technique for solving the shortage of donor organs for patients suffering of end stage organ faliure. We introduced stable isotope labeling with amino acids in a tissue culture setting, which enabeled us to distinguish between the biological scaffold and the proteome of the reppulating cells. Our study gives new insight into ECM turnover in repopulating lung scaffolds and the technique will be a valuble tool for future studies of cell-ECM interaction in tissue engeneering.