In scaffold-based tissue engineering, controlling the macro- and micro-architecture of a scaffold and fulfilling a customized scaffold design with a complex anatomic shape are of great importance for the clinical success of a tissue engineering strategy. In order to achieve extensive and detailed control over scaffold architecture, solid free-form fabrication (SFF), also called "rapid prototyping (RP) technologies", is introduced into the tissue engineering field and have been developed for scaffold production. This chapter presents our investigations into the fabrication of three-dimensional (3D) calcium phosphate (Ca-P)/ poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposite scaffolds through the use of selective laser sintering (SLS). A new strategy of using nanocomposite microspheres instead of dry-blended bioceramic-polymer powders as raw materials for SLS is adopted. A commercial SLS machine is modified to reduce the consumption of raw materials in scaffold fabrication. Based on designed scaffold models, nanocomposite scaffolds with well-defined architecture and pore structure can be fabricated via SLS. For using SLS-formed nanocomposite scaffolds as vehicles for the controlled release of biomolecules such as growth factors, both entrapment and attachment strategies are investigated. As a demonstration of the entrapment strategy, Ca-P/PHBV microspheres loaded with bovine serum albumin (BSA) are fabricated and sintered into 3D porous scaffolds. BSA-loaded nanocomposite scaffolds display controlled in vitro release behavior. However, there are problems in this biomolecule entrapment approach for SLS-formed scaffolds. Using the attachment strategy, recombinant human bone morphogenetic protein- 2 (rhBMP-2) can be loaded onto surface-modified scaffolds through non-covalent binding. The scaffold surface modification by heparin not only provides a means to protect the loaded rhBMP- 2 but also improves the sustained release behavior of rhBMP-2. The integration of advanced scaffold fabrication technology and nanocomposite and growth factor delivery to form multifunctional tissue engineering scaffolds holds promises for successful bone tissue regeneration.
|Original language||English (US)|
|Title of host publication||Handbook of Intelligent Scaffolds for Tissue Engineering and Regenerative Medicine|
|Publisher||Pan Stanford Publishing Pte. Ltd.|
|Number of pages||29|
|Publication status||Published - Jan 31 2012|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)