Adsorption of bovine serum albumin onto synthetic calcium hydroxyapatite: influence of particle texture

Effects of Acetonitrile on Adsorption Behavior of Bovine Serum Albumin onto Synthetic Calcium Hydroxyapatite Particles

“…Here, it should be noted that the particle length of Hap-3 is 3.1 to 3.7 times that of Hap-1 and Hap-2. We reported previously that this difference in the particle length is fairly significant (19) and that the saturated amount of adsorbed BSA is strongly dependent on the particle length but less so on Ca/PO 4 atomic ratio because the fraction of predominantly crystal faces (ac or bc faces), proportional to the fraction of C sites, increased with elongating the particle. Bovine serum albumin (isoelectric point [IEP] = 4.7, A-7030) was purchased from Sigma.…”

“…• C for 16 h. The recipes for these particle preparations have been reported in detail elsewhere (19,20). These particles were identified to pure Hap crystal by conventional methods of XRD and FTIR, and these particles were characterized by TEM, TG-DTA, and N 2 gas adsorption experiments, as reported in our previous studies.…”

“…Calcium and phosphorus contents in the particles were assayed using inductively coupled plasma (ICP) spectroscopy. The details of the characterization methods have also been reported elsewhere (19,20). The physicochemical properties of the Hap particles that were considered to influence BSA adsorption are summarized in Table 1.…”

“…In general, the chromatography should be carried out at pH values higher than about 5, where the crystal structure of Hap is thermodynamically stable (18). We have investigated fundamentally in our previous studies and revealed that acidic bovine serum albumin (BSA) preferentially adsorbs onto C sites of Hap but that basic lysozyme mainly adsorbs onto the phosphate ions on ac or bc faces of the Hap at pH 6 in aqueous media (19)(20)(21). A method of separating acidic and basic proteins from each other by applying double gradients of KCl buffer was also developed (17).…”

Adsorption of Bovine Serum Albumin and Lysozyme on Hydrophobic Calcium Hydroxyapatites

“…Nowadays, calcium hydroxyapatite [Ca 10 (PO 4 ) 6 (OH) 2 , denoted CaHAP] receives much attention in these fields because this material is a major inorganic component of biological hard tissues and possesses a high affinity for biomolecules (1)(2)(3)(4)(5). From this practical significance, we have investigated the protein adsorption behavior not only onto CaHAP but also onto various kinds of synthetic hydroxyapatites (HAPs), such as CaHAP, strontium HAP (SrHAP), calcium strontium HAP (CaSrHAP), and carbonate-containing CaHAP (CAP) (6 -12).…”