Genetically controlled self-assembly of inorganic-bioorganic hybrid structures: From sponge genes to layered functional materials

在数百万年的时间里，海绵已经进化出了制造和组装水合无定形二氧化硅的能力，这些无定形二氧化硅形成了复杂的分层形态（针状体），它们是分层结构的。人为合成二氧化硅需要腐蚀性化学物质和高温的结合，而海绵的基因调控生物硅化在水环境中以高保真度在环境条件下发生。此外，生物源形成的无机-生物有机杂交体具有非凡的性能，远远超过人类的工程能力。随着硅蛋白（酶）和硅蛋白（支架蛋白）的发现，利用生物硅化的多种工具已经成为可能。硅蛋白具有广泛的底物特异性，已被用于制造纳米结构的生物二氧化硅和其他通过传统化学合成无法获得的创新复合材料。硅粉蛋白引导硅单体组装成细丝，同时，引导纳米颗粒组装成合成针状体。该项目的目标是利用这些蛋白质的自组装、结构导向和生物催化能力，结合各种纳米级构建块，用于产生具有新特性组合的生物启发纳米结构材料。为此，基因修饰的原体（3D海绵细胞培养）将被用作生物工厂。此外，生物工程蛋白将用于设计具有附加功能的体外智能材料（例如，热响应性，自我修复和机械应力传感）。

Over millions of years, sponges have evolved the ability to fabricate and assemble hydrated amorphous silica into complex, layered morphologies (spicules), which are hierarchically structured. While anthropogenic silica synthesis requires a combination of caustic chemicals and high temperature, the gene-regulated biosilicification of sponges occurs with high fidelity at ambient conditions, in an aqueous environment. In addition, the biogenously formed inorganic-bioorganic hybrids have extraordinary properties, far exceeding human engineering capabilities. With the discovery of silicatein (enzyme) and silintaphin (scaffold protein), versatile tools have become available to harness biosilicification. Silicatein has broad substrate specificity and has been used to manufacture nano-structured biosilica and other innovative composites that cannot be obtained through traditional chemical synthesis. Silintaphin directs the assembly of silicatein monomers to filaments and, concurrently, the assembly of nanoparticles to synthetic spicules. The goal of this project is to exploit self-assembly, structure-directing and biocatalytic capabilities of these proteins, in combination with various nanosized building blocks, for the generation of bioinspired nanostructured materials with new property combinations. For this purpose genetically-modified primmorphs (3D sponge cell culture) will be used as biofactories. In addition, bioengineered proteins will be employed to design in vitro smart materials with added functionalities (e.g., thermoresponsiveness, self-healing, and mechanical stress sensing).