NANOSTRUCTURE AND BIOACTIVITY OF MOUSE LUNG EXTRACELLULAR MATRIX SCAFFOLDS

Extracellular matrix (ECM) forms an essential part of tissue microenvironment. Compositional and structural properties of ECM modulate behaviour of cells, including their differentiation, proliferation, and turnover. Here we aimed at detailed characterization of the nanostructure of lung ECM and evaluation of its bioactivity on cells grown in vitro. Mouse lungs were decellularized using 0.2 % sodium dodecyl sulphate, hypotonic solutions, and DNase. Morphological analysis of the resulting ECM scaffolds was performed by means of transmission and scanning electron microscopy. The ECM scaffolds retained 3D architecture of the main lung anatomical regions: the alveolar region and the blood/ airway network. The region-specific ECM nanotopology and organization of ECM macromolecules such as fibres of collagen, elastin, and fibrillin were characterized. The lung ECM scaffolds were also homogenized and applied as a supplement to growth medium on primary lung cells in vitro to test the bioactivity of lung ECM. We demonstrate that homogenized ECM does not have a negative impact on the proliferation rate of primary lung cells. In conclusion, we herein show at nanoscale the morphological characteristics of lung ECM and demonstrate that lung ECM produced by decellularization procedure is compatible with in vitro cultured lung cells. These findings add to a better understanding of cells with their natural environment and can be valuable when designing applications of ECM for purposes in tissue engineering.