Bone replacement material with optimized structure, manufactured using additive printing technology

Additive manufacturing with Arburg Plastic Freeforming (APF), an extrusion-based additive manufacturing process, was used to produce biomimetic bone scaffolds for assistance of osteosynthesis made of poly-caprolactone (PCL) with channel structures for the ingrowth of blood vessels. The specific creation of defined channel structures is very important to support the ingrowth of blood vessels, which significantly supports the regeneration of natural tissue. The tibia model used was divided into the corticalis and the spongiosa to be able to compare the realization of the different requirements of the two natural structures with the printed structures separately. Microtome cuts of the manufactured bone scaffolds with channels were prepared for characterization with light microscopy. Compression tests were carried out on a tensile testing machine. It was found that the channels in the tibial cortex led to a slightly higher stiffness compared to those without channels due to the frame outlines. Overall, however, the stiffness of the Polycaprolactone (PCL) scaffolds was significantly lower than that of natural bone. In the spongiosa scaffolds, the stiffness with channels was lower than that without channels, but still within the physiological range, as was the model without channels. The porosity was within the required range for both scaffold types.