Synthesis Of Size-Controlled Rod-Like Hydroxyapatite (Ha) And The Interaction Between Ha And Bovine Serum Albumin (Bsa)

Hydroxyapatite (HA, Ca10(PO4)6(OH)2) is an excellent non-toxic and non-corrosive inorganic biological material. It is widely applied in biomedical research area. Bovine serum albumin (BSA) is often used in biochemical experiments as a common globulin in bovine blood. In this dissertation, a size-controlled rod-like hydroxyapatite nanoparticle was prepared using hydrothermal synthesis method. The interaction between the as-prepared HA and BSA was also studied.Hydrothermal synthesis was used to prepare the rod-like hydroxyapatite. The effects of the raw materials, the hydrothermal temperature, the holding time, the pH and the dispersants on HA s morphology and size were systematically investigated. These factors were further optimized by applying orthogonal designs.The rod-like HAs were prepared by using CaCl2and (NH4)2HPO4as the raw materials. NH4OH was used to control the pH of the reaction solution. It shows that the length-to-diameter ratios of larger than90%of HA products lay in the range of2-6under the conditions of pH11and maintaining120℃and150℃for longer than25h. The experimental factors were of importance in the order of the reaction temperature> holding time> pH.The interaction between hydroxyapatite and bovine serum albumin was also systematically investigated in this dissertation. It was found that the amount of BSA adsorption was gradually decreased with the increase of the concentration of phosphate in PBS solution. However, it is increased with the concentration of NaCl. The amount of BSA adsorption on HA was increased with its concentration and it reached adsorption equilibrium at at1.6mg/mL. The thermodynamic adsorption model of BSA on HA accorded with Langmuir model and the maximum adsorption and the Langmuir constant were87.51mg/g and0.01202mL/mg, respectively. In addition, it is also found that this adsorption reached equilibrium in90min while the desorption reached equilibrium in50min. Both the adsorption and desorption kinetics accord with the pseudo-second-order model. The adsorption rate constant (k’) and the adsorption capacity at equilibrium (qc) were0.5657min-1and106.38mg/g, respectively; while the desorption rate constant(k’) and the desorption capacity at equilibrium (qe) were3.692min1and37.24mg/g, respectively.