Protein adsorption behaviors onto photocatalytic Ti(IV)-doped calcium hydroxyapatite particles

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 87; no. 2; pp. 472 - 479
• Main Authors: Kandori, Kazuhiko, Kuroda, Tomohiko, Wakamura, Masato
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.10.2011
• Subjects: Adsorption; Adsorption behaviors of proteins; Animals; Binding Sites; Borides; bovine serum albumin; calcium; Calcium hydroxyapatite; Cattle; Charged particles; Chemistry, Pharmaceutical - methods; colloids; Drug Compounding - methods; Durapatite - chemistry; Durapatite - metabolism; heat treatment; Hot Temperature; hydroxyapatite; ions; Kinetics; lysozyme; Magnesium compounds; Muramidase - chemistry; Muramidase - metabolism; myoglobin; Myoglobin - chemistry; Myoglobin - metabolism; Particle Size; Photocatalysis; photocatalysts; Photocatalytic Ti(IV)-doped calcium hydroxyapatite; Photochemical Processes; potassium chloride; Protein Binding; Serum Albumin, Bovine - chemistry; Serum Albumin, Bovine - metabolism; sorption isotherms; Static Electricity; Surface chemistry; titanium; Titanium - chemistry; Titanium - metabolism; Titanium dioxide; Titanium oxide; zeta potential; Adsorption behaviors of proteins; Photocatalytic Ti(IV)-doped calcium hydroxyapatite; Titanium oxide; Calcium hydroxyapatite
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2011.06.010

[Display omitted] • We examined protein adsorption onto photocatalytic Ti 4+-doped apatite particles. • Photocatalytic apatite particles possess a high adsorption capability for proteins. • Heat treatment induces a higher adsorption capability for proteins. • Commercially available photocatalytic TiO 2 particles have low protein adsorption. The fundamental experiments on the adsorption behaviors of proteins onto photocatalytic Ti 4+-doped calcium hydroxyapatite (TiHap) particles were examined comparing to those onto the calcium hydroxyapatite (CaHap) and commercially available typical titanium oxide (TiO 2) photocatalyst (TKP-101). The heat treated TiHap and CaHap particles were also used after treated these particles at 650 °C for 1 h (abbreviated as TiHap650 and CaHap650, respectively). All the adsorption isotherms of bovine serum albumin (BSA), myoglobin (MGB) and lysozyme (LSZ) from 1 × 10 −4 mol/dm 3 KCl solution were the Langmuirian type. The saturated amounts of adsorbed BSA ( n s BSA ) for the CaHap650 particles was higher than that for CaHap. Similar results were observed for TiHap and TiHap650. The adsorption of LSZ exhibited the same result of BSA, while the saturated amounts of adsorbed LSZ ( n s LSZ ) value on the TiHap were much higher than CaHap. However, the saturated amounts of adsorbed MGB ( n s MGB ) are almost equal to those for the CaHap and TiHap nevertheless whether these particles were heat treated at 650 °C or not. The TKP-101 exhibited extremely small adsorption capacity of all proteins due to its small particle size of ca. 4 nm in diameter. The independence of the n s MGB value on the zeta potential (zp) of the particles was explained by the electrostatical neutrality of MGB molecules. On the other hand, the n s LSZ values were increased with increase in the negative zp of the particles. This fact was explained by increasing the electrostatic attractive forces between negatively charged particles and positively charged LSZ. However, the n s BSA values exhibit maxima for the heat treated TiHap650 and CaHap650 particles. This result was interpreted to the formation of β-TCP crystal phase by the heat treatment. The produced Ca 2+ ions by dissolution from β-TCP phase may exert as binders between BSA and surfaces of the heat treated particles.