Inhibition Mechanism of Calcium Oxalate Crystal Growth by Cooperation Influence of Colloidal Selenium Nanoparticles and Bovine Serum Albumin

Abstract

This study investigated the effect of colloidal selenium nanoparticles modified with bovine serum albumin (nanoSe0–BSA) on the crystal phase and morphology of CaC2O4 and explained the cooperative inhibition mechanism of nanoSe0 and BSA on the crystallization of CaC2O4. The results were compared with those for nanoSe0 and BSA individually. NanoSe0 could induce the formation of oval or spherical calcium oxalate monohydrate (COM) crystals at high concentrations. BSA could induce the formation of hexagonal plate-shaped COM crystals at low concentrations and the formation of thin diamond-shaped COM crystals and mixed hydrates with cracks at high concentrations. NanoSe0–BSA showed additive effects on CaC2O4 crystal growth. NanoSe0–BSA could induce the formation of mixed hydrates with more surface cracks and obvious voids at relatively low BSA concentrations. These mixed hydrates were considered to be calcium oxalate trihydrate (COT) or calcium oxalate dihydrate (COD) crystals containing BSA or nanoSe0–BSA. These results were a consequence of the interaction of nanoSe0 with BSA. UV–vis, circular dichroism, and FT-IR spectra indicated that the binding of nanoSe0 to BSA induces a change in the secondary structure of BSA and forms the complex. The nanoSe0–BSA binding constant (2.257 × 104 L mol–1) and number of binding sites (1.13) were calculated from the data of fluorescence spectra.