Synthesis of Hydroxyapatite in Microemulsion and its Adsorption Properties for Human Serum Albumin

Hydroxyapatite (HAP) was synthesized in Triton X-100 microemulsion and was characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS). Particle size analysis results showed that the particles has nanometer size, high surface area and loose structure. The prepared HAP had high adsorption capacity to human serum protein and the adsorption of human serum protein on the surface of HAP was confirmed by SEM. The factors which influenced the adsorption capacity such as the acidity, reaction time and the concentration of adsorbent were investigated in detail and the adsorption isothermal was also obtained. The adsorption capacity reduced while the pH value increased, and the adsorption reached equilibrium when shaking time was up to 40 min. The adsorption isotherm could be fitted by the pseudo-Langmuir type. The adsorption of human serum albumin on HAP was investigated, and the influences of adsorption on the conformation of human serum albumin were studied by infrared and ultraviolet spectroscopy. It can be seen from the FT-IR spectra that the intensity of flex vibration of C=O, N-C bonds all weakened. The calculation results of ultraviolet spectrum indicated that the quantity of α spiral structure reduced from 44% to 17.12%.