Fabrication and characterisation of polymer and composite scaffolds based on polyhydroxybutyrate and polyhydroxybutyrate-co-hydroxyvalerate

Abstract

This paper reports the fabrication and characterization of three-dimensional, highly porous polyhydroxybutyrate (PHB), polyhydroxybutyrate- co-valerate (PHBV) and composite scaffolds made by the emulsion freezing / freezing-drying technique. Freeze-drying of the polymer/solvent/ water phase emulsions produced hard and tough scaffolds with interconnected pores. The effects of the fabrication parameters such as polymer concentration in emulsions and emulsion stabilizer were examined and optimized. The density of polymer scaffolds was found to increase with an increasing polymer concentration. Structural analyses of selected samples using scanning electron microscopy indicated that the scaffolds had pore sizes ranging from several microns to a few hundred microns. The porosity of scaffolds of up to 85% was achieved and it increased with a decreasing polymer concentration. It was found that mechanical properties of composite scaffolds increased with the increasing amount of hydroxyapatite (HA) incorporated in the scaffolds.