Preparation of an rhBMP-2 loaded mesoporous bioactive glass/calcium phosphate cement porous composite scaffold for rapid bone tissue regeneration

In this work, a novel composite scaffold was constructed by combining mesoporous bioactive glass (MBG) and calcium phosphate cement (CPC) materials using a simple centrifugal embedding approach. Furthermore, recombinant human bone morphogenetic protein-2 (rhBMP-2) was facilely incorporated into this scaffold through a freeze-drying process. It is found that the resultant scaffold not only presents a hierarchical pore structure (interconnected pores of around 200 μm and 2-10 μm) and a sufficient compressive strength (up to 1.4 MPa), but also exhibits excellent drug delivery properties, presenting sustained release of rhBMP-2 for over 7 d. In order to evaluate the osteogenetic capacity of the rhBMP-2 loaded MBG/CPC scaffold, in vitro cell culture with bone marrow stromal cells (BMSCs) was conducted. Notably, this composite scaffold presents a favorable effect on the proliferation and osteogenetic differentiation of BMSCs. Furthermore, in vivo bone tissue regeneration was conducted using a rabbit radius defect model. It is demonstrated that the incorporation of rhBMP-2 can induce a significant improvement of osteogenetic efficiency, especially in the early stage. Moreover, better biodegradability was obtained in the rhBMP-2 loaded MBG/CPC scaffold compared to the others. Therefore, it is anticipated that the rhBMP-2 loaded MBG/CPC scaffold is of great potential in the field of rapid bone tissue regeneration.