Σχεδιασμός και κατασκευή βιοαντιδραστήρα για ιστούς οστών

The diploma thesis discusses the design, manufacture, and technical assessment of the bioreactor made by 3D printing for bone tissue engineering. This bioreactor integrates controlled perfusion of the scaffold with culture medium and cyclic axial compression. The thesis continues the student thesis of the author, from which the requirements for the design of the bioreactor were derived. The EnduroBone bioreactor served as the main reference for the design work. In the first stage of the work, the theoretical background on bioreactors and bone tissue engineering has been outlined. An overview of selected 3D printed perfusion bioreactors and systems that integrate perfusion with mechanical and biophysical stimulation is provided as well. The design of the single-chamber prototype, which is comprised of a culture chamber with the scaffold holder and four perfusion ports allowing the direct flow through the scaffold and peripheral flow, has been described. The other components of the design include the frame made of aluminum profiles, the compression mechanism with a carriage, which transmits movements to the lid of the chamber through magnetic coupling, the perfusion system with four peristaltic pumps and the control system made on the basis of Arduino Mega 2560 boards and RAMPS 1.4 shields. The lid and the chamber were manufactured by stereolithography from a biocompatible resin while the structural parts were created from PETG. The technical evaluation consisted of the gravimetric calibration of the pumps, which showed a linear relationship between the flow rate and the velocity setting of the driver (R²=0.99998), the leakage test of the chamber and the circuit with no signs of leakage and testing of the operation of the cyclic compression with a stroke of 15 mm at frequency 0.07 Hz. The biological assessment of the bioreactor was made using SaOS-2 cells and comprised the test for cytocompatibility of the resin used for the chamber, which showed no evident cytotoxic effect, and static culturing on 3D printed PCL scaffolds. After four days of static culture, cell nuclei were found on the surface of the scaffolds and in the internal grid of the scaffolds, which confirms the attachment of the cells to the PCL scaffolds. The dynamic culture in the bioreactor is proposed as future work.