This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).
INTELLECTUAL MERIT: Polysaccharides provide structural and mechanical properties for tissues and organs, and they have binding domains for proteins such as enzymes, cytokines, growth factors, and other extracellular matrix components. They are therefore excellent candidate materials for introducing both biomechanical and biochemical functionality into materials for applications such as tissue engineering. Their chemical and physical properties are affected by their polyelectrolyte nature which arises from pendent carboxylic acid, amine, and sulfate moieties. These electrostatic interactions dominate such phenomena as self-assembly, protein binding, and interactions at surfaces and interfaces, and can be used to tune the nanostructure and surface properties of polysaccharide-based materials. The overall goal of this work is to develop techniques to tailor the assembly of complex polysaccharide nanostructures. To accomplish this goal, three research objectives will be achieved: (1) Construct a series of synthetic analogs of a biologically derived polysaccharide nanostructure, aggrecan, with tunable architecture, so that the effects of its nanostructure on solution structure and dynamics can be discerned. (2) Tune the nanoscale structure and composition of polysaccharide-based nanoparticles and surface coatings. (3) Develop complex assemblies of polysaccharide nanostructures, and use them to engineer mimics of biological nanostructures based on polysaccharides, such as the aggrecan aggregate. Polyelectrolyte multilayers, polyelectrolyte complex nanoparticles, and electrospun nanofibers will be employed to control the composition and organization of materials in rectangular, spherical, and cylindrical coordinates, respectively. In the third objective, we will develop techniques to combine these three types of nanostructures into more complex assemblies.
BROADER IMPACTS: The success of this research program will provide a new understanding of the physical chemistry and nanoscale organization of an important class of biological materials. This will enable the engineering design of materials that mimic the structure and organization of tissues. The technology developed here will be incorporated into a new course at Colorado State University on the physical chemistry of biomacromolecules, for students in the new interdisciplinary School of Biomedical Engineering at Colorado State University. Participating graduate and undergraduate students will be trained to work at the interface of engineering and biology by applying their engineering expertise to problems in biology and medicine. The PI has established collaborations with researchers in the Colleges of Veterinary Medicine and Agriculture that will give students opportunities to interact with researchers from a variety of disciplines. The PI will develop and deliver a two week summer short course for high school students on polymers that will include daily morning lecture and afternoon laboratory components. The underlying theme for the short course will be that the properties and performance of polymers that they can witness over many length scales and time scales are ultimately related to the molecular architecture. The course will introduce students to polymers beginning with everyday examples and then discuss some of the interesting properties and familiar applications of polymers through topics they can relate to. Polymer production will be introduced through products they are familiar with such as kitchen wrap and disposable plastic kitchenware, polymer solubility will be introduced through discussions of recycling, and polymer solutions and viscoelasticity will be discussed through ?polymers in the kitchen.? Laboratory experiments will be designed that are low-cost and can be easily reproduced in a typical high school classroom. The course will be offered to twelve high school students and one to three high school science teachers at local (Fort Collins) public high schools and the Denver School of Science and Technology (DSST). DSST is a public charter school with a population of 28% Hispanic and 29% African American students. At DSST 40% of the students come from low-income families. Including students and teachers from DSST is a deliberate strategy to help improve the enrollment of underrepresented minorities in STEM disciplines.
