Bone Regeneration Materials

Biomaterials Center is composed of five groups and collaborate each other to examine interdisciplinary fields of biomaterials. In the ceramics-based biomaterials research, we have been developing three novel bone regeneration materials, i.e., high-porosity hydroxyapatite (HAp) ceramics with high-strength, guided bone regeneration (GBR) membranes and bone-like nanocomposite composed of HAp and collagen. The GBR membrane composed of β-tricalcium phosphate and biodegradable copolymer of lactide, glycolide and ε-caprolactone has thermoplastic, pH auto-adjustment and enough mechanical property to protect an invasion of surrounding tissues. With the membrane, bone defect up to 20 × 10 × 10 mm3 in length in mandibles and segmental bone defect up to 20 mm in length in tibiae of beagles are regenerated without any additional bone fillers or cell transplantations. The bone-like nanocomposite is synthesized by a co-precipitation of HAp and collagen via their self-organization. The dense composite has a half to quarter mechanical strength (40 MPa) to cortical bone and the porous one demonstrates sponge-like viscoelasticity. The composites implanted into bone are incorporated into bone remodeling metabolism like as autogenous bone graft, i.e., they are resorbed by osteolasts followed by osteogenesis by osteoblasts.