Craniofacial Graft Manufacturing
Rapid manufacturing or rapid prototyping includes several manufacturing methods such as stereolitography, fuse deposition, inkjet and extrusion printing. Some of these techniques are applicable to print biological materials together with living cells and are called biofabrication techniques. Our group uses inkjet and extrusion based bioprinting to create cellular tissue grafts in our daily research.
Although the vast variety of commercial bioprinters and other rapid manufacturing machinery the biocompatible printing materials, so called bioinks, are being developed. Discovery of new bioinks that can be used widely in bioprinting will revolutionize the medical field in patient specific graft manufacturing and personalized medicine.
We are working with the projects optimizing these bioinks for 3D manufacturing of tissue grafts. Our ECM paste bioinks are designed based on natural polysaccharides as carrier and support materials for decellularized cartilage particles. This ECM paste bioink is further mixed with chondrocytes or other chondrogenesis supporting cell types and biological crosslinker molecules.
The bioink compositions are analyzed for biocompatibility, tissue quality and rheological properties. Rheological properties including shear thinning, thixotrophy, and extrusion relaxation are investigated for optimizing bioink compositions for the printing process. Biocompatibility and tissue quality is analyzed with cell viability assays, histological and immunohistochemical stainings.
Layer-by-layer manufactured extrusion printed structures replicate the patient specific shape to customize the tissue graft manufacturing process. Furthermore, developing of layer specific bioinks gives us the possibility to produce high resolution cartilage structures together with surrounding soft tissues. Designing the architectural support and engineered porosity enhance the cell survival in large structures without sacrificing the mechanical properties.
Matti Jaakko Johannes Kesti