Natural Lung Material Is Promising Scaffold For Engineering Lung Tissue Using Embryonic Stem Cells

The use of a cell-depleted lung as a natural growth matrix for generating new rat lung from embryonic stem cells is discussed in this article. The use of the natural cytoskeleton of the lung as an optimal matrix is because it contains the extracellular matrix (ECM) components necessary for structural support for the biochemical and biophysical interactions that occur in the lung, and because it meets the biocompatible and elastic requirements necessary to support the organs functions.

After decellularizing the lung by freezing, enzymatic digestion, and detergent treatment, culture of murine embryonic stem cells (mESCs) was utilized on the acellular rat lung to study cell attachment, survival, and differentiation along lung-specific lineages. Matrigel, gelfoam, and collagen I matrices were used to compare the influences of the different properties. After 7 days of culture, cells were isolated from each matrix. Acellular lung matrix resulted in a higher number of viable cells and a lower percentage of apoptosis. The expression of prosurfactant protein C by type II pneumocytes, CD31 by endothelial cells, and cytokeratin epithelial cells were significantly higher than the other matrices compared, suggesting significantly higher levels of cells differentiating toward the selected lung lineages. After 14 days, the production of laminin and collagen IV by the differentiating mESCs was observed, as well as complex tissue formation in the upper lung.

Embryonic stem cells require a specific environment and chemical cues to differentiate into specific cell types and continue to develop into 3D tissue structures. One of the challenges lies in fabricating appropriate environments for embryonic stem cells to recognize specific matrix signals so they may differentiate into appropriate cell types. By developing lung tissue from a decellularized lung, the researchers have demonstrated that natural ECM as a matrix is suitable for use in regenerative medicine.

The use of stem cells in 3D scaffolds has a great potential for future regenerative medicine methods. Whether synthetic or natural, scaffolds offer a way for cells seeded or encapsulated to proliferate and differentiate into appropriate lineages, while expressing specific components of a natural ECM. Further development in this field has the potential to grow organs for transplant purposes in animals and humans. This area of research is very interesting to me due to the above reasons.

http://www.medicalnewstoday.com/articles/198441.php

http://www.liebertonline.com/doi/pdfplus/10.1089/ten.tea.2009.0730