Systemically replicated organic and inorganic bony microenvironment for new bone formation generated by a 3D printing technology

Abstract

Here, bone demineralized and decellularized extracellular matrix (bdECM) was coated on the surface of the 3D printed polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and beta-tricalcium phosphate (TCP) mixture scaffolds (PCL/PLGA/TCP) that induce in vitro osteogenic activity and in vivo critical sized bone defect healing. Collagen coating on PCL/PLGA/TCP was used as a positive control. bdECM coating on PCL/PLGA/TCP successfully proceeded maintaining its pore interconnective structure. PCL/PLGA/TCP/bdECM showed the highest osteoblast adhesion with alignment morphology. These enhanced cell adhesion and alignment might contribute to in vitro osteogenic activity of osteoblasts combined with osteogenic biomolecules in bdECM. Furthermore, in vivo bone defect healing was enhanced compared to the other scaffolds. Three type of scaffold (PCL/PLGA/TCP, PCL/PLGA/TCP/Col, and PCL/PLGA/TCP/bdECM) with or without osteoblasts were implanted into the mouse calvarial defect. In vivo bone healing was measured by microcomputed topography and histological staining. PCL/PLGA/TCP with or without osteoblast implantation on the mouse calvarial defect only showed fibrous tissue formation. PCL/PLGA/TCP/Col with osteoblasts showed the half ratio of bone healing. However PCL/PLGA/TCP/bdECM without osteoblasts showed significantly enhanced bone defect healing. This result indicated that PCL/PLGA/TCP/bdECM is sufficient to induce the critical bone defect healing due to the bdECM containing biomolecules and enhanced host cell ingrowth into the defect.