This proposal is directed toward the preparation of sol-gel derived silicate structures by biomimetic processes. Organosilicon and germanium probes will be synthesized and their effects on representative species of diatoms will be screened. Diatoms produce an ordered deposition of amorphous silicon dioxide from supersaturated silicate solutions. Ordered deposition of silicon dioxide is a major objective of sol-gel. The results of screening studies should indicate which of the alternatives for control of silicon dioxide deposition in vivo are most accessible to biomimetic sol-gel processing: 1. Observation of complexes of silicic acid analogs with simple molecules, leading to high solubility of monomeric or oligomeric silicates analogous to dcca (drying control chemical additives) in sol-gel. 2. Inhibition and possibly isolation of ionophoretic silicate transport complexes. 3. Inhibition and possibly isolation of proteins or polysaccharides involved in deposition of silicates from sili-calemmas or other higher order diatom structures. There is a possibility that organosilicon or germanium com- pounds could be incorporated into the silicate structures, yielding new materials by bioprocessing. The future objective would be to pursue the most viable of the alternatives developed by the initial screening: possible utilization of small molecules identified in Phase I or synthetic analogs directly as a DCCA additives; alternately, information suitable for development of markers for isolation or development of genetically engineered polysilicate synthesis may be generated. The two most likely forms of invention or discovery from this proposal are either a non-biochemical system for the control of silicate synthesis developed from biological DCCA's or a biochemical system, presumably protein mediated silicate synthesis. The utilization of a biochemical system would imply development of genetically engineered production of the active protein.
Keywords: Sol-Gel, Biomimetic, Diatoms, Organosilicon
