Shaotang Yuan

An investigation of zirconium(IV)–glycine(CP-2) hybrid complex in bovine serum albumin protein matrix under varying conditions

The morphological and structural transformation process of the water soluble zirconium–glycine hybrid cluster [Zr6(O)4(OH)4(H2O)8(Gly)8]12+ (CP-2) in a bovine serum albumin (BSA) protein matrix was comprehensively investigated. Based on the zeta-potential analysis, positive CP-2 clusters tend to adsorb onto the surface of the backbone of BSA, forming BSA–CP-2 hybrids through direct mixing. After aging the solution at 37 °C for several weeks, white floccules appeared in solution indicating the phase transformation of BSA–CP-2 bio–inorganic hybrid. A series of characterizations (zeta-potential measurements, dynamic light scattering measurements, transmission and scanning electron microscopy, X-ray diffraction, and so on) were carried out to analyze the interaction between CP-2 and BSA under varying pH value and salt concentrations in order to demonstrate the transformation of the CP-2 to amorphous ziconium hydroxide. The coagulant action of CP-2 with BSA indicates that the zirconium(IV)–glycine complex may be efficacious as an antiperspirant and in water treatment.

Ultrathin hybrid films of polyoxohydroxy clusters and proteins: layer-by-layer assembly and their optical and mechanical properties.

The hierarchical assembly of inorganic and organic building blocks is an efficient strategy to produce high-performance materials which has been demonstrated in various biomaterials. Here, we report a layer-by-layer (LBL) assembly method to fabricate ultrathin hybrid films from nanometer-scale ionic clusters and proteins. Two types of cationic clusters (hydrolyzed aluminum clusters and zirconium-glycine clusters) were assembled with negatively charged bovine serum albumin (BSA) protein to form high-quality hybrid films, due to their strong electrostatic interactions and hydrogen bonding. The obtained hybrid films were characterized by scanning electron microscope (SEM), UV-vis, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), and X-ray diffraction (XRD). The results demonstrated that the cluster-protein hybrid films exhibited structural homogeneity, relative transparency, and bright blue fluorescence. More importantly, these hybrid films displayed up to a 70% increase in hardness and up to a 100% increase in reduced Youngs modulus compared to the pure BSA film. These hybrid cluster-protein films could be potentially used as biomedical coatings in the future because of their good transparency and excellent mechanical properties.