Tracheal decellularization using a combination of chemical, physical and bioreactor methods

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cell Biology

Background:

• Decellularization is key for creating tissue scaffolds.
• Conventional detergent enzymatic method (DEM) is widely used but can be time-consuming.
• Optimizing decellularization protocols is essential for scaffold quality and immunogenicity.

Purpose of the Study:

• To compare different decellularization protocols against the conventional DEM.
• To evaluate the efficiency and impact of sonication, lyophilization, and bioreactor-based methods.
• To assess cellularity and extracellular matrix integrity post-decellularization.

Main Methods:

• Compared conventional DEM with sonication and lyophilization+freeze-thaw cycles.
• Evaluated time-adjusted DEM against bioreactor-based decellularization.
• Assessed cellularity via DNA quantification, H&E staining, and MHC-1 immunostaining.

Main Results:

• 4 cycles of DEM significantly reduced DNA content below minimal criteria for efficient decellularization.
• Sonication and lyophilization methods showed efficient DNA removal after 4 cycles, but residual cells and MHC-1 staining indicated potential immunogenicity.
• Bioreactor-based decellularization, even after 4 cycles, did not consistently meet minimal DNA removal criteria, though it preserved collagen and glycosaminoglycans better than DEM.
• DEM showed significant glycosaminoglycan reduction after initial cycles.

Conclusions:

• Efficient decellularization was achieved with 4 cycles of DEM, a significant reduction from 17 cycles previously reported.
• Bioreactor use is advantageous for preserving the extracellular matrix integrity during decellularization.
• Further optimization is needed for bioreactor protocols to ensure complete cellular removal while maintaining matrix integrity.