Porosity distribution affecting mechanical and biological behaviour of hydroxyapatite bioceramic composites.

The present work aims to the study of developing porosity in hydroxyapatite (HAp) scaffold by using graphite porogen (with 0–30 vol%) followed by engineering the changes achieved by conventional- (CS) and microwave-sintering (MS) techniques. The generated porosity was controlled between ~6–27% as the porogen concentration increases in HAp scaffold. Voronoi tessellation was utilized in order to evaluate the distribution of pores. The enhanced mechanical properties including fracture toughness (0.83 MPa m 1/2 ), fracture strength (7.5 MPa), and hardness (183.7 VHN) were observed for microwave sintered HAp scaffold with 8% porosity. The fitting between porosity and fracture strength elicited that microwave sintered HAp with 8% porosity provides maximum crack-propagation resistance while restricting grain size (~0.23 µm) and eliciting high extent of sintering (~1.34) because of their rapid heating rates. The cell viability (MTT assay) and cell culture confirm the cytocompatibility of porous HAp for application as bone implant that need accelerated replacement of bone tissues. [ABSTRACT FROM AUTHOR]