Degradable and Bioactive Synthetic Composite Scaffolds for Bone Tissue Engineering

Abstract

There is significant information and knowledge acquired in the last years on the fabrication, characterisation, and application of bioactive composite scaffolds based on combinations of biodegradable polymers and inorganic fillers intended for bone tissue engineering. Of particular importance is the complete understanding of the degradation behaviour of these scaffolds in order to assess the effects of pore structure, scaffold geometry, permeability, and the influence of bioactive fillers on the scaffold mechanical properties and biological performance. The present chapter examines the development of such bioactive and biodegradable scaffolds discussing their mechanical properties and degradation behaviour. A general background on biodegradable polymers with focus on the fabrication and properties of scaffolds made from polyesters is included, followed by a complete overview of the development of scaffolds based on biodegradable polymer/bioactive glass composites. The general degradation behaviour of composite polymer/inorganic phase scaffolds is presented and a specific example is discussed, e.g. poly(d,l lactide) (PDLLA)/bioactive glass composite, based on recent results on a long-term (600 days) degradation study in simulated body fluid. Remaining areas of research in this field are indicated, highlighting the need for appropriate characterisation techniques coupled with predictive analytical models and the requirement for accurate characterisation of the interface between the polymer matrix and the inorganic fillers in order to ascertain the scaffold degradation behaviour in vitro and in vivo.