Programming the Design, Assembly, and Function of Mesoporous Peptide Crystals

About This Grant

NON TECHNICAL SUMMARY: From desalination membranes to sensors for detecting nerve agents to drug delivery carriers, porous materials represent a critical materials class that supports myriad applications. Over the past several decades, there have been significant advances in developing porous materials with tailorable physical and chemical properties from non-biological components (e.g., metal ions, organic molecules, etc.). However, there is a growing interest in fabricating functional porous materials from biological building blocks (e.g., proteins and peptides), which display unparalleled levels of structural, chemical, and functional diversity as evidenced by the complex and functional assemblies that are ubiquitous in biology. The goal of this project is to establish a new, synthetic route towards building porous materials from peptide-based building blocks. Peptides are ideal assembly building blocks, because they can be synthesized directly in the lab and thus their structural and chemical properties can be systematically tuned to create programmable materials that perform alongside their biological counterparts. Moreover, because they are synthesized chemically, one can easily integrate non-biological features to further diversify and enhance peptide-based materials with novel properties that extend beyond nature. This NSF project establishes a new family of porous materials that are derived from synthetically modified collagen-mimetic peptides. Results from this project aim to demonstrate that their chemical and physical features, i.e., pore chemistry and pore size, can be systematically engineered through altering the peptide sequence design. The outcomes from this project will be packaged into assembly design rules that will be used as a blueprint for creating future porous biomaterials that are suitable for biological and environmental applications. Broader impacts of this project involve providing hands-on research and professional experiences for area high school students to engage in cutting-edge scientific research, which is a critical step for maintaining and growing the pipeline of new American talent to enter the STEM workforce. TECHNICAL SUMMARY: This NSF project establishes a novel class of mesoporous frameworks that are self-assembled from amphiphilic collagen-mimetic peptides (aCMPs). These aCMPs comprise two domains: (1) a crystallizable collagen-mimetic peptide domain and (2) a hydrophobic domain comprising an alkyl chain that is appended to the N-termini of the CMP domain. Both domains, which contain electrostatic and hydrophobic driving forces, work synergistically to assemble into crystalline frameworks comprising hexagonally arranged, 1D mesoporous channels. This project entails three research aims that center on engineering the peptide sequence design to systematically adjust the pore size (Specific Aim 1) and pore chemistry (Specific Aim 2) of aCMP frameworks, and to demonstrate the potential utility of this materials class by encapsulating functional guest species, including proteins and inorganic nanoparticles via covalent and non-covalent interactions (Specific Aim 3). The knowledge obtained from this project serves as a guide for the development of future porous biomaterials with customizable physical and chemical properties, which is important for developing functionally relevant materials for applications in health, catalysis, separations, and sensing. The broader impacts of this project afford the education and training of area high school students to STEM research through supporting a 9-week summer research program at UC Merced and the dissemination of that research at an ACS Western Regional Meeting (WRM). These educational and professional activities bolster the training of the future American STEM workforce. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.