Biomimetically Co-Deposition of Bovine Serum Albumin and Calcium Phosphate on 3D Printed Hydroxyapatite: Influence of Time, Temperature and Concentration

Abstract

Influence of bovine serum albumin (BSA) concentration, soaking times and soaking temperatures during biomimetic co-deposition process of three dimensionally printed hydroxyapatite (3D printed HA) on weight change, phase composition and microstructure were studied. At 23°C, weight change of all samples monotonically increased with increasing soaking time regardless of BSA concentration used while the weight change initially increased, but leveled off later with increasing soaking time when using solution temperature of 37°C. At 50°C, weight change initially increased for up to 4 h and remained constant for up to 16 h where the weight decreased afterward. This decrease could be related to the competition between the dissolution of 3D printed HA, the deposition of new calcium phosphate crystals and the incorporation of BSA during biomimetic process at high temperatures. From X-ray diffraction, no influence in BSA concentration, time and temperature on the phase composition was observed. Scanning electron microscopy revealed the deposition of new plate-like calcium phosphate crystals on all 3D printed HA. Hydroxyapatite and octacalcium phosphate were found to be the main phases of all biomimetically BSA.