NANOSCALE: Nanoscale Self-Assembled Block Copolypeptide Materials

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

Abstract - Deming - 9986347 The PI's plan to study the self-assembly of block copolypeptides as synthetic materials that possess the ability to aggregate and/or "fold" into specifically defined, functional nanostructures. The internal structure and nanoparticle shape are key features of these assemblies that should impart the materials with exceptional attributes for applications in sensor technology as well as drug and gene therapeutics. By understanding the rules by which such block copolypeptides self-assemble, one should be able to prepare new, well-defined nanostructures that can be tailored for specific applications. The PI's will be focusing on the self-assembly of these block copolypeptides in solution, primarily with water as the solvent. By working with polypeptides, it is expected that the secondary structures present in the block domains will substantially alter the structures of the aggregates. They also plan to explore the nanoscale self-assembly of multiblock copolypeptides (three or more domains), where the number of discrete structural components might allow individual or small numbers of chains to adopt specific tertiary (3D) structures of defined shape. The controlled aggregation of block copolymers into discrete complexes with tertiary structure has yet to be accomplished, yet such materials, constructed of amino acids, would certainly be invaluable for biomedical applications. Examples would be drug and gene delivery, where the shape of the complexes favors selective interactions with different biological surfaces. In addition to defining the nanostructure of aggregates, the secondary structures of block copolypeptides have the added feature that they can be sensitive to environmental changes, such as pH, solvent or temperature. This property can be utilized for the construction of nanoscale assembled complexes that will be able to change their shape when exposed to different conditions. Such features are useful for sensing applications or for programmed release of biologically active compounds in delivery applications. To accelerate the discovery and understanding of these new, complex nanostructures, the PI's plan to couple automated parallel synthesis and processing methods with state-of-the-art analytical tools to rapidly screen the many parameters of block copolypeptide phase space (e.g. composition, sequence, temperature, solvent). The speed of this approach will allow the exploration of highly complex polymer sequences possessing nanoscopic folding and self-assembly properties that will rival those of biological proteins. Such structure and function specific assemblies will have wide ranging applications in the areas of biomimetics, biomineralization, tissue engineering, high strength fibers, polar or surface-active films and coatings, and optoelectronic devices and sensors. The major tasks of this project are (i) the synthesis of block copoly peptide libraries, (ii) processing of the crude polymers to assist self-assembly, (iii) rapid screening of the libraries to identify lead compounds and novel structures, and (iv) detailed characterization of new nanostructured materials. The successful demonstration of these components will verify that combinatorial methods can be applied successfully to the preparation and analysis of nanostructured materials. More significantly, this methodology will allow the future exploration of highly complex biomimetic materials that would otherwise be near impossible to study solely because of the number of possible variables in their composition.