Research Of Synthesis Mechanism And The Applications Of Phosphate/Yeast Protein Nanocomposites Via Catalysis Strategy

By means of the multi-crossed disciplines among the principle of microbial fermentation, cytoarchitectonics and the principle of biomineralization, this paper presented a novel synthetic method which its own peculiar multilevel nanostructure of yeast cell tissues was copied with phosphate required or metabolized by human, by taking living yeast cells as templets and reactors. A series of phosphate nano-composite materials with complex surface shapes were synthesized, and synthesis mechanism, structure, composition and performance were researched systematically.CHA/yeast protein nanocomposite has been synthesized successfully by using yeast cells as the catalytic templates. The orthogonal test was used to optimize the synthetic parameters and its scale-up experiment was carried out. The results showed that its structure and composition had a good repetition and can be synthesized in batch. The present technology has many advantages including the mild reaction conditions, simple process, no pollution and easy to industrial production. The modern testing technologies were used to characterize the structure and composition of the synthetic samples. The synthetically analysed results indicated that the hydroxyl-carbonate-apatite (CHA) crystal nano-grains with the lower crystallinity were rapidly formed in the physiological environment of yeast calls, which has the unit cell parametersα=9.4924?, c=6.9092 ?. Compared with HA nanopowders (α=9.2329?,c=6.7707 ?) obtained by direct precipitation method, distortion phenomenon existed in the lattice structure of nano-CHA and metastable rich Ca layer with positive electrical property were formed by the aliquation of Ca atoms and CO32- groups on the surface and grain boundary of CHA particles. Nano-CHA grains were dispersed evenly in the herarchical network structure of yeast proteins, and copied the complex nanostructure in yeast cell.The CHA/yeast protein nanocomposite exhibited a unique fluorescence enhancement effect, because of the unique multi-level porous and nano-composite structures, and the distorting lattice structure of nano-CHA. It has the performance of transfection fluorescence to bone marrow stem cells of rat, onion cells, Saccharomyces cerevisiae, Aspergillus oryzae and Escherichia coli. The cell proliferation and hemolytic experiments in vitro show that L-929 fibroblasts had well adherence and proliferation properties on the sample surface , the toxic degree of the samples was in zero grade standard and it had no hemolysis. CHA/yeast protein nanocomposite has the visible effects loaded and slowly released insoluble drug, the quantity loaded insoluble drug amoxicillin is up to 112.16 mg/g, the drug was embedded in the porous structure of the carrier, which have sustained release rate and no burst phenomenon, and the total amount of drug releasing is up to 55% after 6 days. The dynamic equation released amoxicillin drug from the carrier belongs to Fick's diffusion control model, which mainly were control by the two mechanisms of the drug diffusion and the carrier degradation. The hierarchical porous structure and catalysis of residual proteases in CHA/yeast protein nanocomposite improved its degradation property. The CHA mineralization with heterogeneous nucleation is easy in the electric double layer formed on its grain surface. Therefore, CHA/yeast protein nanocomposite is degradable bioactivity nanomateriale and had unique amphiphilic property (contact angleθ=120°), left optical activity (specific rotation[α] 25℃D =-23°) and good affinity to hydrophobic drug. Specially, beacause there are 17 kinds of amino acids needed by human in the yeast protein, it is also a multifunctional drug carrier material supplemented with complete proteins and calcium trace element and a fluorescence-labelled material.Phosphates (Zn, Fe and Mg)/yeast protein nanocomposites have been synthesized successfully by using yeast cells as the catalytic templates, respectively. Phosphates/yeast protein nano-composites were calcined at different temperatures for 2h to synthesize various phosphates/active C nano-composites. The results indicated that both Zn3(PO4)2 4H2Oand rich Mg bobierite crystal grains have (020) preferred growth. The amorphous iron phosphate (core) with globulin in yeast cell can self assemble to form the grains with core-shell structure. These particles were dispersed in the herarchical network structure of yeast protein. The synthetic samples can emit different color fluorescences under different excitation wavelengths, and have the performance of transfection fluorescence to onion cells, Saccharomyces cerevisiae, Aspergillus oryzae and Escherichia coli. The synthetic samples possess better electro-catalytic activity than commercialized MnO2 catalyst. The differences of catalytic activity of samples obtianed at different temperatures in the oxidation reduction were attributed to porous structures and in situ-composite activated carbon. These materials can be used as a catalyst for oxygen electrode materials used in bio-sensors, metal-air battery, fuel cell, etc. These synthetic hybrid materials can also be used as fluorescent labeling materials.The study results of the synthetic mechanism shown that different metal ions adsorbed in yeast cell have different effects on the structure and composition of proteins. The order of amino acid content in the synthetic samples is Mg>Ca>Fe>Zn, the effect order on the ordered degree of protein structure is Ca>Fe>Mg>Zn. Different metal ions were adsorbed on the surface of different protein molecules by gene regulation in yeast cell, have preferred growth along the special direction according to layer growth theory. Phosphates/yeast protein nanocomposites with different morphologies were formed by supramolecular self assembly of protein molecules. These materials have herarchical porous structure with vermiform morphology, the range order of their pore size distribution is Fe(2～60nm)>Ca(2～40nm)>Mg(2～24nm)>Zn(2～12nm), and the sites of fast heterogeneous nucleation are all polar hydrophilic groups arranged orderly on helical grooves in metabolic network of yeast cell. The biomineralization of yeast cells involves four processes: ion adsorption, ion transmission, deposition mineralization and supramolecular self-assembly, which were divided into mineralization induced by organism on cell wall and growth controlled by organism in cell.