CAREER: Hybrid Bio-Synthetic Polymers: Controlling Structure and Function on Nanometer Scales in Genetically Engineered Polymers Enhanced with Synthetic Blocks.

Northwestern University, Evanston IL

Investigators

Abstract

Controlling and manipulating molecular building blocks on a nanometer scale is the central challenge of the emerging field of nanotechnology. Nature accomplishes this task by synthesizing numerous exact copies of high molecular weight protein molecules, with folding and function on nanometer scale encoded in the primary sequence of their amino acid monomers. Thus, the cellular apparatus of protein synthesis is uniquely suited for making giant molecules with properties controlled on a nanometer scales. However, natural materials also have many shortcomings, both in terms of the available chemical building blocks, as well as the limited flexibility of the linear, step-wise protein biosynthesis. Thus, combination of the precise natural biosynthetic process with favorable attributes of diverse unnatural synthetic blocks could be used to create materials with properties impossible to obtain with purely synthetic or natural synthons. The PI propses a research program aimed at exploring the synthesis and applications of novel materials consisting of genetically engineered polypeptides (protein polymers) conjugated with synthetic macromolecular building blocks: dendrons and/or conventional polymers. Two specific aims will be addressed in the proposed research: (1) development of a synthetic route towards monodisperse cylindrical molecules with nanometer-scale length and diameter, and controlled distribution of polar and apolar surface chemistries, that can be used as building blocks for thin films and monolayers with nanoscale molecular ordering; (2) synthesis and processing of composites consisting of ordered, nanometer-sized polypeptide blocks dispersed in a synthetic polymer matrix, that will have high mechanical strength and toughness comparable to or better than those of the natural dragline spider silk fibers. %%% The PI will complement his interdisciplinary research effort with a teaching program designed to integrate the biology and materials science education. The PI's ultimate aim is to educate the next generation of sscientists and engeineers capable of working at the interface between the two disciplines. This will be realized by designing research projects at the interface between biology and polymers science and suitable for both undergraduate and graduate research. Furthermore, the PI will develop three new undergraduate materials science classes that will introduce concepts and techniques of life sciences to engineering students in the context of biomaterials. Ultimately, the proposed research and training program will facilitate the flow of ideas and techniques between the two disciplines. This will then lead to the discovery of new methods for synthesis of materials with diversity of functional properties approaching those of natural biopolymers, and having stability and processing characteristics suitable for application in many areas of nanoscale science and engineering.