Controlled Hybrid Material Synthesis using Synthetic Biology

The concept of creating a hybrid material is motivated by the development of an improved product with acquired properties by amalgamation of components with specific desirable traits. These new attributes can range from improvements upon existing properties, such as strength and durability, to the acquisition of new abilities, such as magnetism and conductivity. Currently, the concept of an organic-inorganic hybrid material typically describes the integration of an inorganic polymer with organically derived proteins. By building on this idea and applying the advanced technologies available today, it is possible to combine living and nonliving components to synthesize functional materials possessing unique abilities of living cells such as self-healing, evolvability, and adaptability. Furthermore, artificial gene regulation, achievable through synthetic biology, allows for an additional dimension of the control of hybrid material function. Here, I genetically engineer E. coli with a tightly controlled artificial protein construct, allowing for inducible expression of different amounts of the surface anchored protein by addition of varying concentrations of L-arabinose. The presence of the surface protein allows the cells to bind nonliving nanoparticle substrates, effectively turning the cells into living crosslinkers. By using the living crosslinker, I was able to successfully synthesize a robust, macroscale living-nonliving hybrid material with magnetic characteristics. Furthermore, by varying the particle size and inducer concentration, the resulting material exhibited alterations in structure and function. Finally, I was able to manipulate material kinetics within a PDMS channel by applying fluctuating magnetic fields and demonstrate material durability. These results demonstrate the ability to manipulate synthesis of livingnonliving hybrid materials, which demonstrate the potential for use in promising applications in areas such as environmental monitoring and micromachining. Additionally, this work serves as a foundational step toward the integration of synthetic biology with tissue engineering by exploiting the possibility of controlling material properties with genetic engineering. Controlled Hybrid Material Synthesis using Synthetic Biology Felicia Yi Xia Scott General Audience Abstract Creating a hybrid material is appealing because the resulting product has properties from both elements. For example, an example of a hybrid car combines a combustible gas engine for power and an electric drive system to reduce gas emissions. The result is an automobile that is more fuel efficient and environmentally friendly, but does not compromise in power or speed. In other cases, the addition of an element may be in order to improve upon existing properties, such as strength or durability. Alternatively, new elements may introduce new properties such as magnetism or conductivity. Although the current field is more focused toward nonliving organic elements, here, I will introduce a living organic element to my hybrid material. Living organisms allow the introduction of an even wider range of unique abilities such as self-healing, evolvability, and adaptability. Furthermore, through DNA modifications, an additional dimension of the control of hybrid material function may also be introduced. Here, I endow E. coli cells with the ability to produce artificial proteins on their surfaces. Furthermore, I am able to control the amount of protein produced by changing the amount of chemical, L-arabinose, present. The protein anchored to the cell’s surface are able to attach to nonliving magnetic nanoparticles, allowing them to act as living material builders, referred to as crosslinkers. The result is a robust, macroscale livingnonliving hybrid material with magnetic characteristics. Additionally, the sizes of the particles and the amount of the chemical (resulting in corresponding anchored protein concentrations), effect the resulting material and its structure. Finally, a setup was created to observe the material when magnetic force was applied. The results demonstrate unique characteristics of the material, showing its potential for use in applications such as environmental monitoring or micromachining. This work serves as a critical step for the integration of synthetic biology with tissue engineering by exploiting the possibility of controlling material properties with genetic engineering.