Investigating the degradation behaviour and characteristic changes of phase pure hydroxyapatite (HAp) microsphere scaffolds under static and dynamic conditions

Abstract

ABSTRACT Hydroxyapatite (HAp) has been widely researched on due to its chemical similarity to native bone. HAp microspheres can encourage good cellular attachment due to their high surface area to volume ratio, facilitating further proliferation and differentiation of cells at later stages. To ensure the reliability and effectiveness of HAp microspheres in physiological conditions, we investigated their behaviour and key characteristic changes in both static and dynamic conditions. We found both environments exhibiting similar results but noticeably the microspheres in the dynamic environment resulted in faster rate of degradation. The degradation mechanism follows that of a surface degradation process. Microspheres underwent reduction in size and weight loss upon release of Ca2+ ions into Dulbecco’s Phosphate Buffered Saline medium (DPBS). Apatite reprecipitation was visible in the form of granular deposits in both environments from day 1 and continued throughout 21 days which altered the size of the microspheres but not its shape.