Innovative shaping approach for manufacturing personalized bone replacement materials

Until now, it was hardly possible to manufacture real bone-looking synthetic bone replacement material featuring a distinctive and complex-shaped outer shell and a porous inner filling in one single component, just like a real bone. The presented idea though, shows an innovative and novel approach to develop just such porous, near-net shaped bone-mimicking structure for personalized and customer-adapted next-generation bioceramics. The solution offers a co-manufacturing process which unites the advantages of a sponge-like foam producing method called Freeze Foaming and a reproducible and tool-less, three-dimensional additive manufacturing approach called Lithography-based ceramic manufacturing (LCM). As one advantage the so-called freeze-foaming process offers the possibility to achieve mainly open porous and interconnected sponge-like structures without any CO2-producing pore formers or similar volatile whole PU-scaffolds. Achieved hydroxyapatite (HAp) and/or zirconia (ZrO2) foams provably allow the osteogenic differentiation of hMSCs on the detection of alkaline phosphatase and collagene-1. Foamed as a hybrid mixture obtained ZrO2/HAp composites exhibit significantly increased compressive strength whilst biocompatibility is retained. Most of all though, the near-net shaping feasibility of these Freeze Foams allows to foam for instance, the inner contours of a LCM-assembled ceramic scaffold. After a specific co-manufacturing and -sintering step a single complex-shaped demonstrator of a down-scaled human femur made of biocompatible zirconia was obtained which features structural and mechanical advantages of both shaping approaches. However, this is just the beginning. Recent activities are concerned with the very co-manufacturing of biodegradable and/or partly biodegradable structures for next-generation bioceramics/-composites used as personalized implants which, additionally, allow a yet impossible targeted adaption according to the needs of customers.