Combining 3D-Printing and Tissue Decellularization—A Novel and Cost-Effective Approach

Objectives: The decellularization (DC) of different biomaterials is widely used to develop scaffolds for medical implants and tissue engineering applications. Usually, immersion and agitation techniques are used for DC processes. This study presents a novel approach using a 3D-printed bioreactor system for DC of pericardial patches, as well as pulmonary and aortic roots.

Methods: A bioreactor system was developed to simultaneously decellularize ten pericardial patches or five aortic vessels, respectively. Flow profiles and pressure distribution inside the bioreactors were optimized by steady-state computational fluid dynamics (CFD) analysis. Subsequently all parts of the bioreactors were 3D-printed in a commercial fused deposition modeling printer using polylactic acid as printing material. Afterwards, all printed parts were surface modified using chloroform to smoothen surface and to reduce wall friction. Bovine pericardia (n = 30), porcine pulmonary arteries and porcine aortae were decellularized (n = 10 each) using sodium dodecylsulfate and sodium desoxycholate (0.5/0.5%). Groups treated by a conventional immersion and shaking technique were used as controls. Treatment effects were evaluated and compared by histological assessment and biomechanical testing. Additionally, production and material costs were calculated and compared.

Results: CFD analysis of the pericardial bioreactor revealed even flow and pressure distribution between all 10 pericardia. Subsequent CFD analysis of the vessel bioreactor showed increased intraluminal flow rate and pressure compared to the vessel’s outer wall. SEM analysis showed a smooth surface finish on all printed parts following surface modification. Complete removal of cell nuclei and a significant reduction of residual DNA was achieved for all samples treated with the 3D printed bioreactors. In contrast, DAPI staining revealed residual nuclei in pulmonary and aortic vessels of the control group. Biomechanical assessment showed no significant difference between the DC and control groups. Production costs of the 3D-printed bioreactor were calculated at 200¢ (incl. pump), while the required amount of DC solution was reduced by 20% compared to the conventional setup.

Conclusion: It was possible to newly develop a 3D-printed, low-cost bioreactor system for DC purposes. The bioreactor was digitally optimized in order to provide ideal flow profiles. DC results showed superiority to conventional treatment procedures.

No conflict of interest has been declared by the author(s).