ABSTRACT
This chapter addresses a unique way that hydroxyapatite (HA) is used: as a coating material on polymeric scaffolds. It introduces some of the commonly used biodegradable polymers as substrate first, followed by HA coating techniques on them. Among the biodegradable synthesized polymers, most commonly investigated in implant and drug delivery systems are the following polymers: poly(ortho ester), polyanhydride, poly(caprolactone) (PCL), poly(lactic acid), poly(glycolic acid), and poly(lactic-co-glycolic acid). A new design developed in blending PCL with other biodegradable polymers to provide opportunities to change the drug release rate. Polymer scaffold is chosen as an artificial implant due to biocompatibility, biodegradability, high mechanical strength, and osteoconductivity. In order to improve mechanical strength and osteoconductivity, some researchers designed layer of apatite coating on the surface of the polymer scaffold. The difference between their structures determines their biomedical application: HA coating on scaffold is applied to improve the bioactivity and bioadhesion, while HA-coated microparticles/nanoparticles are carriers for bioactive molecular drug delivery.
