Bio-Nano Interfaces and Engineering Applications: Bio-Nano Interfaces: Fundamentals II
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

Tuesday 8:30 AM
February 28, 2017
Room: Pacific 21
Location: Marriott Marquis Hotel

Session Chair: Hendrik Heinz, University of Colorado Boulder; Stefano Corni, University of Modena

8:30 AM  Invited
Computational Models of Peptide-Surface Interactions Drawn from Bacterial Display Studies: Margaret Hurley1; Meagan Small1; Dimitra Stratis-Cullum1; Deborah Sarkes1; Justin Jahnke1; Jessica Terrell1; Hong Dong1; 1US Army Research Laboratory
    Over the last decade, concurrent advances in both computer hardware and in experimental techniques have led to the possibility of a truly iterative research process in which both modeling and experiment play a vital role. Here we discuss the development of classical and quantum mechanical computational models of the interaction of genetically engineered peptides with metal and metal oxide surfaces such as gold and alumina. Use of these models in conjunction with experiment imparts a deeper fundamental understanding of the binding process and is essential to design and ultimate control of the living material interface.

9:00 AM  
Formation of Planer Lipid Bilayers on 2D Materials Assisted by Self-assembled Peptides: Takakazu Seki1; Tomohiro Tanaka1; Yuhei Hayamizu1; 1Tokyo Institute of Technology
    Biological molecules, such as lipids and proteins, largely govern intricate biological functions of cells through ion channels, molecular recognizers, and catalysts embedded in the cell membrane. These sophisticated functions might come from interplays between a fluidic lipid bilayer and proteins in a controllable self-assembling manner. Aiming to combine the biological sophisticated functions with a two dimensional (2D) materials such as MoS2, we utilize peptides self-assembling on 2D nano-sheet as a glue between a lipid bilayer and 2D materials towards the opto-electronic applications. Using appropriate peptides, planer lipid bilayers were successfully formed on various 2D materials. The fluidity of lipid bilayer was modulated by the type of peptides. Using fluorophore tagged lipids, the fluidity of the planer lipid bilayer was evaluated by a technique of the fluorescence recovery after photo-bleaching. Optoelectronic property of MoS2 coated with assembled peptide/lipid was also investigated.

9:20 AM  Invited
Computational Design of Biological-Inorganic Materials from the Nanoscale: Hendrik Heinz1; 1University Of Colorado-Boulder
    The mechanism of specific adsorption of bio-macromolecules onto metallic and oxidic nanostructures will be explained in atomic resolution resulting from simulations with novel force fields and surface models in comparison to measurements. As an example, variations in peptide adsorption on Pd and Pt nanoparticles depending on shape, size, and location of peptides on specific bounding facets are determined by soft epitaxial processes and induced charges. On oxidic nanoparticles such as silica and apatites, it is shown how changes in pH lead to similarity scores of attracted peptides lower than 20%, supported by model surfaces of appropriate surface chemistry and adsorption isotherms. The results demonstrate how new computational methods can support the design of structured hydrogels, nanoparticle carriers for drug release, and the understanding of calcification mechanisms in the human body. The main features of the INTERFACE force field for accurate simulations of inorganic/organic and inorganic/biological interfaces will be discussed.

9:50 AM Break

10:10 AM  Invited
Atomistic Simulations of the Interaction of Gold Surfaces and Nanoparticles with Amyloidogenic Proteins and Peptides: Stefano Corni1; 1CNR Istituto Nanoscienze
    Experiments have demonstrated that inorganic nanoparticles and surfaces can either accelerate or inhibit the fibrillation of amyloidogenic proteins and peptides, depending on the nanoparticle material, their size, and the experimental conditions of the experiment. Some general mechanisms leading to acceleration and inhibition (such as enhanced nucleation or sequestration from the solution, respectively) have been identified; much less is understood on the role of the specific interactions between a given peptide and a given surface in affecting fibrillation propensity. In this contribution, our atomistic simulation results for amyloid-beta peptides and b2-microglobulin protein interacting with bare and functionalized gold surfaces and nanoparticles will be presented, and the possible mechanisms leading to inhibition or enhancement of fibrillation will be discussed.

10:40 AM  Invited
Modeling of Nanocomposite Scaffolds and Interfacial Behavior during Tissue Regeneration and Scaffold Degradation: A Multiscale Mechanics Approach: Dinesh Katti1; Anurag Sharma1; Kalpana Katti1; 1North Dakota State University
    Mechanical response of biomaterials over time is currently experimentally driven through animal testing. These studies do not provide accurate prediction of mechanical properties of scaffolds over time. In this work, a multiscale mechanics-based approach is developed to model the degradation of nanocomposite bone tissue engineering scaffolds. The scaffolds are fabricated from amino acid modified montmorillonite nanoclay (OMMT), with biomineralized hydroxyapatite (HAP) followed by incorporation into polycaprolactone (PCL). We have built molecular models of the OMMT-HAP-PCL that accurately predict its mechanics and structure. Steered molecular dynamics simulations evaluate the load-deformation behavior which is used to develop finite element models of scaffolds with the microstructural details from microCT. The evolution of scaffold mechanics due to degradation and tissue growth is experimentally obtained and used with damage-mechanics models to develop a predictive capability of scaffold property evolution. This unique multiscale mechanics based approach allows prediction of response of implanted bone scaffolds over time.

11:10 AM  
Designing Peptides with Antimicrobial Properties using Rules of Induction: Kyle Boone1; Kyle Camarda1; Candan Tamerler1; 1University of Kansas
    The emergence of multi-drug resistant bacteria has become a major concern in recent decades. On the other hand, many biological organisms have been relying on antimicrobial peptides to fight off bacterial infections through innate immunity responses. As an example of recent antimicrobial peptide design, we have demonstrated their utilization as novel localizable molecules onto medical implant surfaces with bactericidal effect. Further development of peptides with targeted properties can be offered using a computer-assisted molecular design (CAMD) problem. Many databases for antimicrobial peptides provide sequences for quantitative sequence-activity models solving the forward problem in CAMD. We built a method for classifying antibacterial sequences using descriptive classifiers from rule induction. In addition, we combine the classification technique with a genetic algorithm to solve the reverse problem of CAMD. Our model presented here provides a method to design novel antimicrobial peptides through rule induction by discovering sequence-function relationships building upon chemical property analysis.

11:30 AM  Invited
Interfacing Biomolecules with Nanomaterials: Structure and Function at the Atomic-scale: Tiff Walsh1; 1Deakin University
    Exerting molecular-level control over the interaction of peptides with materials interfaces, including nanoparticles will benefit a range of areas such as biosensing, catalysis, energy, and nano-medicine. Exploitation of materials-selective binding of biomolecules is key to success in these areas; i.e. by realizing preferential adsorption of a biomolecule onto a desired materials composition, facet or polymorph. Structural characterization of the surface-adsorbed biomolecules is essential for establishing the required structure/property relationships in these systems, but is challenging to accomplish via experimental approaches alone. In partnership with experiment, molecular simulations can bring complementary insights into the origins of this selectivity, and suggest routes to manipulating these phenomena. Our team develop and apply advanced molecular simulation techniques to investigate biomolecule/materials interfaces. I will outline our recent progress in this area and discuss our findings for bio/nano applications in e.g. sensing, catalysis and energy applications.