Characterization of Mechanical and Micro-Architectural Properties of Porous Hydroxyapatite Bone Scaffold Using Green MicroAlgae as Binder

Novel Hydroxyapatite (HA)-based porous bone scaffold is developed using green microalgae as binding as well as pore-forming agent. The composite scaffolds are developed at 1:2, 2:1 and 1:1 (w/w) compositions of HA and binder, respectively, using solvent-casting technique and their mechanical and micro-architectural properties are investigated. Material characterization of the scaffold shows improved mechanical strength with a maximum compressive strength of 2.89MPa and maximum interconnected porosity of 65.29%. FT-IR and XRD results confirm formation of crystalline nano-HA in the scaffolds. SEM and TEM micrographs of the scaffolds show pore morphology with a maximum pore diameter of 258 microns and minimum pore diameter of 6 microns and uniformly dispersed rod-shaped nano-HA particles of length 3.95-99.11nm, respectively. TG/DTG analysis shows high thermal stability of scaffolds with high HA content. Comparative study of the three types of scaffolds shows composites with equal weight ratio of HA, and binder yields the highest porosity and mechanical strength desired for cell growth and support. XRF analysis confirms Ca and P as the major constituent elements of the scaffold. The study highlights the potential of natural biomass as an alternative to synthetic and naturally derived polymeric binders for development of HA-based bone scaffolds.