The application of rapid prototyping technologies in constructing nanocomposite scaffolds for bone tissue engineering

Abstract

In scaffold-based bone tissue engineering, three-dimensional scaffolds mimic the structure and functions of extracellular matrix and support cell adhesion, proliferation and differentiation. There are various techniques for fabricating scaffolds, including conventional chemical engineering methods and advanced manufacturing technologies, known as solid free-form fabrication or rapid prototyping (RP). In recent years, RP techniques attract great attention in the tissue engineering field because they can have precise control of the external and internal structure of tissue engineering scaffolds and overcome some inherent limitations of conventional scaffold fabrication methods. Various groups have investigated several RP techniques, including fused deposition modeling, 3D printing and selective laser sintering (SLS), for producing scaffolds for the regeneration of bone, articular cartilage, ligaments and other tissues. For bone tissue repair, the composite approach has now been widely adopted in developing novel synthetic bone graft as bone tissue itself is a nanocomposite. Combining the composite approach with RP technology, we have been investigating the use of selecting laser sintering in constructing bioceramic-polymer nanocomposite scaffolds for bone tissue engineering. Totally biodegradable nanocomposite scaffolds consisting of osteoconductive Ca-P nanoparticle and PHBV polymer matrix could be made via SLS. SLS processing parameters had strong influences on scaffold structure and properties. Osteoinductivity could be achieved for the scaffolds by immobilizing recombinant human bone morphogenetic protein-2 on strut surface of the scaffolds and releasing it in vivo in a controlled manner.