Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

David H. Thompson

Committee Chair

David H. Thompson

Committee Member 1

Wen Jiang

Committee Member 2

Chengde Mao

Committee Member 3

Jonathan Wilker


High-resolution biomacromolecular structure elucidation is fundamentally important to structure-based drug design and basic research into complex biochemical processes. Cryo-EM is an emerging alternative to XRD and NMR that is complementary in many ways relative to XRD and NMR. Materials approaches to cryo-EM are anticipated to greatly facilitate the cryo-EM process, allowing progress toward a more high-throughput application of cryo-EM to address challenges in structural biology. ^ Various affinity-based approaches inspired by approaches previously introduced for 2D crystallization were developed for facilitation of cryo-EM. A library of affinity lipopolymer constructs were synthesized consisting of lipopolymers of various PEG molecular weights conjugated to lipids displaying varied affinity or covalently-active moieties at their distal termini. Modified-EM grids with stabilized lipid coatings were then used to capture His6-T7 bacteriophage and His6-RplL from cell lysates, purified His8-GFPuv, and nanodisc embedded His6-MalFGK2. Graphene-oxide-NTA-based affinity grids were fabricated via covalent modification of graphene-oxide and monolayer fabrication on a Langmuir trough. These monolayers were characterized by AFM, SEM, and evaluated for specific capture of his-tagged protein targets. These materials were also used to capture his6-GroEL from clarified cell lysates and used to generate a cryo-EM dataset yielding a map with a gold standard resolution of 8.1 Å. A library of polyrotaxanes based on PEG, ?-CD and various endcaps and rotaxanation methods was synthesized. Several of these compounds were further modified with NTA moieties to impart affinity interactions on the tubular polyrotaxane templates which might be used for isolation of proteins and assisted cryo-EM. The laterally- and rotationally-mobile NTA-CD ligating groups enabled the capture of his-tagged proteins of substantially different sizes and facilitated their imaging via AFM, cryo-TEM, and TEM. This material may greatly facilitate cryo-EM analysis of his-tagged proteins by concentrating them into large and readily detectable clusters that enables projection images of the protein structure in all possible 3D orientations. ^ Several families of diblock copolymer-based drug and gene delivery systems were also developed utilizing organocatalytic ring-opening polymerization (ROP) catalyzed by common amidine and guanidine bases. A library of mPEG-b-polycarbonate pendant polymers was synthesized and evaluated as part of a non-viral gene delivery system. The diblock copolymers showed the ability to form nanoparticles, typically 100-250 nm in size, with slightly positive surface zeta-potentials, effectively condensed pDNA at N/P ratios above 10, and showed comparable transfection efficiencies to Lipofectamine-2000 in HeLa Cells. Organocatalytic ROP was also utilized to synthesize small libraries of mPEG-b-poly(ϵ-caprolactone), mPEG-b-poly(trimethylene carbonate) and mPEG-b-poly(lactide-co-glycolide) diblock copolymers including a novel collagen-binding peptide-diblock copolymer conjugate (SILY-PEG-b-PCL) utilizing organocatalytic ROP from a heterobifunctional PEG derivative. A facile and widely applicable synthetic procedure for the synthesis of cyclic amino-acid-N-carboxyanhydride monomers for synthesis of polypeptides utilizing tetrahydrofuran (THF) as solvent was developed and used to synthesize a small library of some novel and previously reported NCA monomers in superior yield and purity.