3D additive fabrication for regenerative therapies: an innovative modular multicomponent work station for 3D Bioprinting in Regenerative Medicine (REGEMAT 3D)

The lack of tissue regeneration after trauma, degenerative diseases and other pathologies is a highly challenging problem to be solved by biomedicine scientists in this century. New advances in stem cell research for the regeneration of tissue injuries have opened a new promising research field. However, research carried out nowadays with 2D cell cultures do not provide the expected results, as 2D cultures do not mimic the 3D structure of a living tissue. Additive Manufacturing techniques, also known as 3D printing, are based on the principle of adding material layer by layer allowing manufacturing complex external and internal shapes with a mesh structure (scaffold). Bioprinting technologies aim at joining together tissue engineering, regenerative medicine and 3D printing disciplines and have emerged as a powerful tool for researchers due to the ability to mimic the 3D structure of any tissue. Bioprinting can help to overcome the problems that researchers have found working with cell cultures in 2D. This thesis is aimed at generating new knowledge and evidence on the use of bioprinting for clinical therapies. In order to do that we have developed an innovative Modular Multicomponent Work Station for 3D Bioprinting in Regenerative Medicine (project called REGEMAT 3D) with its software and manufacturing algorithms, that can manufacture layer by layer 3D constructs with customized external shapes and an internal meshed structure. Besides the system can be configured and adapted to print with a wide range of biomaterials as scaffolds and bioinks. In order to proof the efficacy of the developed system and biofabrication algorithms, chondrocytes have been printed using a novel procedure known as Volume-by-Volume 3D-biofabrication process followed by volume injection filling of the cell loaded bioink. The process divides the printed part in different volumes and injects the cells after each volume has been printed, once the temperature of the printed thermoplastic fibers has decreased. In our study chondrocytes were isolated from osteoarthritic patient´s samples and after characterization were used to test the feasibility of the process. Human chondrocytes were bioprinted together with polylactic acid (PLA) and apoptosis, proliferation and metabolic activity were analyzed. In our trial, chondrocytes survived to the manufacturing process with 90% of viability 2 hours after printing, and after 7 days in culture, chondrocytes proliferated and totally colonized the scaffold, concluding that the use of the developed bioprinting system shows a valuable potential in the short-term development of bioprinted-based clinical therapies for tissue regeneration.Tesis Univ. Granada