Development in biodegradable materials is continuously progressed and partly aimed for advancing biomedical applications, such as porous structures as scaffolds for tissue engineering and controlled/sustained release drug delivery vehicles. Poly(lactic acid) (PLA) and polycaprolactone (PCL) are the most commonly selected biodegradable materials. PLA is known to have high tensile strength and biocompatibility, while its main drawbacks are brittleness and poor elongation at break, which narrow the applications. Alternatively, PCL has high flexibility and also biocompatibility, which is suitable for blending with PLA to improve the properties. Hydroxyapatite (HA) contains calcium phosphate that is similar to the main mineral of bones and teeth. Combination of HA with the biodegradable polyesters gives some advantages to the material, such as high cell adhesion ability. Therefore, the current research interested to prepare PLA/PCL/HA microspheres by using an oil-in-water emulsion solvent evaporation method. The effects of blending ratio between PLA and PCL controlled at 90:10, and percentage of HA loading varied in a range of 10-40% by weight were investigated. The resultant microspheres were characterized in terms of particle size and distribution by using a laser diffraction particle size analyzer. The results showed that the prepared microspheres exhibited a bimodal distribution. The neat PLA was found within 2-15 micron, while the blended particles displayed two distinguished average particle sizes within 1 and 120 micron for small and large sizes, respectively. When HA was included at 10%wt, it strongly affected the size distributions of both PLA and PLA/PCL blends.

Keywords: poly(lactic acid), polycaprolactone, hydroxyapatite, microsphere, polymer blend