Bio-Nano Interfaces and Engineering Applications: Bio-Nano Interfaces: Fundamentals I
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Biomaterials Committee
Program Organizers: Candan Tamerler, University of Kansas; John Nychka, University of Alberta; Kalpana Katti, North Dakota State University; Terry Lowe, Colorado School of Mines

Monday 8:30 AM
February 27, 2017
Room: Pacific 21
Location: Marriott Marquis Hotel

Session Chair: Candan Tamerler, University of Kansas; Terry Lowe, Colorado School of Mines

8:30 AM  Keynote
Principles of Molecular Biomimetics versus Materials Science and Engineering: Mehmet Sarikaya1; 1University of Washington
    Predictably interfacing biomolecules with solid materials is key for drug delivery, enzyme immobilization, implant biofunctionalization, and biosensor signal transduction. Highly specific interactions controlled by proteins enable explicit recognition of solids and formation of intricate supramolecular architectures in nature. Mimicking natural proteins, GEPIs, Genetically Engineered Peptides for Inorganic solids, have recently become ubiquitous molecular tools in the addressable functionalization of and organizations at solid interfaces. Using these highly versatile biomolecules, one can synthesize solids under biological conditions, use them as molecular erectors in nanotechnology, linkers in probe design, and assemblers in bioelectronics. The principles of molecular biomimetics comprise explicit peptide sequences corresponding to definitive folding patterns via molecular recognition leading to specific chemical or physical functions, the process analogous to MSE where processing leads to microstructures and to materials’ functions. Utility of peptides in MSE is the major factor in translating fundamental bio/solid interface knowledge towards novel genetically engineered future technologies.

9:10 AM  Invited
Materials Construction through Peptide Design and Solution Assembly: Darrin Pochan1; 1University of Delaware
    By considering peptidic molecules in the bottom-up materials self-assembly design process, one can take advantage of inherently biomolecular attributes; intramolecular folding events, secondary structure, and electrostatic interactions; to define hierarchical material structure and consequent properties. These self-assembled materials range from hydrogels for biomaterials to nanostructures with defined morphology and chemistry display for inorganic materials templating. The local nanostructure and overall network structure, and resultant material properties, of hydrogels that are formed via beta-hairpin self-assembly will be presented. Slight design variations of the peptide sequence allow for tunability of the self-assembly/hydrogelation kinetics as well as the tunability of the local peptide nanostructure and hierarchical network structure. Additionally, a new system comprised of coiled coil motifs designed theoretically to assemble into two-dimensional nanostructures not observed in nature will be introduced. The molecules and nanostructures are not natural sequences and provide opportunity for arbitrary nanostructure creation and inorganic material templating.

9:40 AM  Invited
Interfaces Drive the Mechanics of Hard Biological Materials: Discrete Element Models and Bioinspired Prototypes: Francois Barthelat1; 1McGill University
    The high performance of hard biological materials relies on the interplay between their architecture and the weak interfaces they contain. Weak interfaces can deflect and bridge cracks, or dissipate energy which would otherwise propagate large cracks. Various numerical models have been used to capture synergies between architecture and interfaces and to guide the design of new engineering materials. Here I will discuss a new approach where we consider the material as an assembly of interfaces which interact through rigid building blocks. This new approach, equivalent to the discrete element method used to model large numbers of small particles, can capture nonlinear behaviors, contacts mechanics and rate effects in a computationally efficient manner. We have used this method to capture the effects of long range interactions in nacre-like staggered composites and in conch-shell like cross plies. These findings are now guiding the design of bio-inspired materials built from ceramics and polymers.

10:10 AM Break

10:30 AM  Keynote
Engineering Solid Binding Proteins to Control Functional Nanostructure Assembly, Solid Interactions and Inorganic Mineralization: François Baneyx1; 1University of Washington
    The integration of combinatorially selected solid-binding peptides (SBPs) within protein scaffolds is a powerful approach to produce hybrid architectures, control biotic-abiotic interactions, and study and manipulate inorganic morphogenesis. Here, I will illustrate each of these processes with an example from our laboratory. In the first, GFP engineered with two SBPs is used to couple biofabricated ZnS:Mn nanocrystals to silica beads and the optical properties of the resulting assembly are exploited for sensitive detection of chloramphenicol following chemical conjugation of a DNA aptamer to the protein shell. In the second, proteins fitted with a silica-binding SBP are homogeneously entrapped within silica sol-gels and chemically released in a continuous or dynamic manner with pH-tunable kinetics. Lastly, mutagenesis of the same silica-binding SBP is used to modulate titania precipitation under equilibrium and non-equilibrium conditions.

11:10 AM  Cancelled
Quasiparticle Approach to Self-assembly Kinetics of DNA and RNA Molecules: Helena Zapolsky1; Mykola Lavrskyi1; Armen Khachaturyan2; 1University of Normandy, Rouen; 2University of California and Rutgers University
    A self-organization is an universal phenomenon in nature and, in particular, is highly important in biological systems. However, there are still significant difficulties of atomic scale prototyping of a slow diffusional self-organization of atoms in complex structures. Our goal was to develop a new theory that provides a computationally effective approach to model this phenomenon. In this approach two novelties have been introduced, a concept of quasiparticles, fratons, used for a description of dynamic degrees of freedom and model Hamiltonian taking into account a directionality, length and strength of interatomic bonds. In this paper the results of modelling describing the spontaneous self-assembly of four different kinds of monomers into a single-stranded polymeric helix and the formation of a double-helix structure obtained by aggregation of complementary monomers on the single-stranded helix playing the role of a template will be presented.

11:30 AM  Keynote
Multidimensional Atomic Force Microscopy for Physical and Biological Interfaces: Seeing the Invisible and Feeling the Insensible?: Ratnesh Lal1; 1University California, San Diego
    All interfacial structures, activity and mechanics at nanoscale have different and mostly undefined features compared to their macroscale conglomerates. Existing tools and methods to obtain such information, including electron microscopy, X-ray diffractions, STM, and super resolution light and fluorescence microscopy and single molecule force/mechanics measurement tools have limited ability for studying complex non-conducting interfaces. We develop multimodal "SMART AFM" integrated with functional analytical tools each individual AFM consisting of an array of conducting cantilevered probes with self-sensing and actuation capabilities. The new AFM-array will enable 1) imaging the network structures and connectivity at nano-to-macro scale, 2) measuring localized electrical and chemical activity, and 3) creating nanoscale functional structures with applications ranging from new opto-electrical devices to imaging of live neural cells at multiple locations simultaneously with independent imaging feedback. Integration of an ion sensing tip on the cantilevers will allow for localized and highly parallel electrical recording of synaptic activity.