2017 Symposium on Functional Nanomaterials: Emerging Nanomaterials and Nanotechnology: Nanomaterials for BT Applications
Sponsored by: TMS Functional Materials Division, TMS: Nanomaterials Committee
Program Organizers: Jiyoung Kim, University of Texas; Stephen McDonnell, University of Virginia; Chang-Yong Nam, Brookhaven National Laboratory; V. U. Unnikrishnan, The University of Alabama; Nitin Chopra, The University of Alabama

Wednesday 8:30 AM
March 1, 2017
Room: Pacific 24
Location: Marriott Marquis Hotel

Session Chair: Stephen McDonnell, University of Virginia; Lanxia Cheng, The University of Texas at Dallas

8:30 AM  
Probing Osteogenic Cell Functionality on Architected Nanolattices with Stiffness Spanning the Low Megapascal Region: Alessandro Maggi1; 1California Institute of Technology
    Creating prostheses that lead to optimal bone remodeling has been a challenge for more than two decades because of a current lack of knowledge of mechanotransduction in three-dimensional environments. Limitations in traditional fabrication and characterization techniques have limited our understanding of the effects that pore size and mechanical cues have on cell behavior. Pore dimensions smaller than 100μm in 3D scaffolds with stiffnesses higher than a few hundred KPa have not been achieved yet. Recent advances in multiphoton lithography allowed us to create 3-dimensional architectures with tunable porosity and variable local and global stiffnesses that reached a region spanning from 2 to 9 MPa. Our nanolattices enabled us to explore how scaffold mechanical properties influence osteoblasts’ functionality in a microenvironment that simulates conditions found in natural bone. Understanding the lower and upper stiffness boundaries for which osteogenic cell functionality is preserved has the potential of leading to better orthopedic implants.

8:50 AM  
Antimicrobial Clay-based Ceramic with Copper Nanoparticles Embedded in 3-D Porosity: Adam Drelich1; Jaroslaw Drelich1; 1Michigan Technological University
    There is an increasing demand for products with surfaces that “intelligently” respond to changing environment and/or personal needs. For example, those surfaces and products that are repeatedly touched in the course of daily activity as well as those in possible contact with bacteria-contaminated water and food, currently pose a serious health threat by harboring infectious agents. The antibacterial and antifungal attributes of copper have been known for thousands of years, although the rational recognition of this antimicrobial property has only occurred in recent decades. In this study, pottery clay was used to manufacture porous ceramic stones. Copper ions were introduced into the inter-planar and porous structure of the clay through an ion exchange process. Then the introduced ions were converted to metallic copper nanoparticles in a hydrogen-reduced atmosphere at elevated temperature. Such ceramic stones with embedded copper nanoparticles release copper ions at a reduced rate and disinfect bacteria-contaminated water.

9:10 AM  
Engineered Bio-functional Silver Nanoparticle Interface Offers Antimicrobial Efficacy with Reduced Cellular Cytotoxicity: Sarah VanOosten1; Esra Yuca1; Banu Taktak Karaca1; Kyle Boone1; Malcolm Snead2; Paulette Spencer1; Candan Tamerler1; 1University of Kansas; 2University of Southern California
    Intrinsic antimicrobial efficacy of silver nanoparticles (AgNPs) makes them a favorable candidate in combating drug-resistant infections. However, cytotoxic effects of AgNP on host cells remains a major safety concern. Functional coatings play a critical role in the biofunctional properties of AgNPs as surfaces directly contact the biological environment. Our approach harnesses the competitive advantage offered by engineered proteins for biomimetic surface functionalization. Here, we produce a bifunctional protein featuring a silver binding domain (AgBP) and green fluorescence protein (GFP) for tracking surface self-assembly. Functionalization was confirmed using localized surface plasmon resonance spectral measurements. GFP-AgBP-coated AgNPs maintained antibacterial efficacy at low concentrations against Streptococcus mutans and out-performed citrate-coated AgNP controls in parallel studies run on fibroblast cells (NIH/3T3) cellular viability and cytotoxicity. The biointerface engineering demonstrated here offers a promising potential to promote the antimicrobial properties of silver while reducing adverse cellular interactions. Support provided by NIH-NIDCR R01DE025476-01.

9:30 AM  
Potential of Magnetotactic Bacteria for the Fabrication of Iron Nanoparticles: T. Thuy Minh Nguyen1; Manish Baviskar1; Paul Bernazzani1; 1Lamar University
    Magnetotactic bacteria are typically found in soils rich in iron. These prokaryote bacteria have the property of using ingesting atoms of iron and generating magnetosomes of nanoparticles of either diamagnetic or paramagnetic nature within each cell. We report on the use of magnerotatic bacteria for the production of uniform nanoparticles of iron (II) oxide (Fe2O3). The potential for applications in the medical field was investigated along with the molecular, physical, magnetic, and thermal properties of the magnetosomes using Fourier transform infrared spectroscopy, epifluorescence microscopy, gel electrophoresis, and differential scanning calorimetry. Results reveal that the magnetic particles are stable and covered by a lipid that layer that suggests a potential application as a drug carrier targeting specific locations.

9:50 AM  
Facile Green Synthesis and Characterization of Water-soluble Superparamagnetic Iron Oxide Nanoparticles-gold Porphyrin Conjugate for Improved Photodynamic Therapy: Olayemi Fakayode1; Oluwafemi Oluwatobi1; Sandile Songca2; 1University of Johannesburg; 2Walter Sisulu University
    Porphyrin has been proven to be an efficient photosensitizer for photodynamic therapy (PDT). However, the problem of undesired localization in non-tumour environments which causes prolong photosensitivity and requirement for more dose has lowered its therapeutic efficacy.To make porphyrin tumour specific, we have successfully conjugated a meso-substituted symmetric 4-hydroxyphenyl porphyrin (THPP) to superparamagnetic iron oxide nanoparticles-gold core-shell nanostructure (SPIONs-Au) via a facile green approach. The SPIONs were precipitated in an alkaline medium from a preheated mixture of glucose and ferric ion before coating with gold. The core-shell nanostructres were characterized using UV-Vis, FT-IR, XRD, TEM, HRTEM, SAED, EDS and vibrating sample magnetometry(VSM) while the conjugate was characterized using UV-Vis, Photoluminescence spectroscopy (PL), FTIR, DLS and Zeta potential. The as-synthesized magnetic porphyrin conjugate exhibited strong attraction towards external magnetic field and high singlet oxygen generation potential sufficient for the eradication of breast cancer cells in vitro.

10:10 AM Break

10:30 AM  
Silver Nanowire Heaters on Glass and Textiles: Sahin Coskun1; Orcun Ergun1; Doga Doganay1; Sevim Polat1; Yusuf Yusufoglu2; Husnu Unalan1; 1Middle East Technical University; 2Material Technologies Department, R&D Center, Arcelik A.S.
    Silver nanowire based thin film heaters can be made transparent and can be easily integrated to textiles. For transparent heaters (TH), Ag NWs were deposited onto glass substrates via simple spray coating. The effect of nanowire density, contact geometry, applied bias, flexing and incremental bias application on TH performance of Ag NW networks were investigated. Ag NW network based THs with a sheet resistance, percent transmittance of 4.3 Ω/sq and 83.3% with a nanowire density of 1.6 NW/μm2 reached to a maximum temperature of 275°C under incremental bias application (5V maximum). On the other hand, silver nanowire decorated cotton fabrics can be heated to 50°C under an applied power density of as low as 0.05 W/cm2. Time dependent thermal response of the fabrics under different applied voltages was investigated. Time dependent stability of the fabrics as well as their stability under different bending and washing conditions were examined.

10:50 AM  
A Novel Strategy for Synthesis of Ultrathin Au Nanowires inside Carbon Nanotubes and Their Atomic Structure Study: Wenbo Xin1; Igor De Rosa1; Jenn-Ming Yang1; Larry Carlson1; 1UCLA
    Ultrathin gold nanowires (AuNWs) have attracted intensive research attention recently. Of particular interest is the study of their crystalline structures at atomic scale. However, it is challenging to reveal their structures at atomic scale because they are extremely fragile under electron irradiation. Herein, we show a novel method for synthesizing ultrathin AuNWs inside carbon nanotubes (CNTs). With the protection of rigid carbon shells, structure stability of ultrathin AuNWs with diameter less than 5 nm is significantly enhanced. Accordingly, gold atoms orientation is well resolved, showing the single-crystalline FCC structure. Furthermore, after CNT walls are removed with 300 keV electron irradiation, bare AuNWs eventually degrade and break into nanoparticles. Angstrom-scaled twins of the nanowires created by electron irradiation could effectively enhance their structure stability.

11:10 AM  
Wetting Kinetics and Self-pinning of Nanosuspension Droplets: Baiou Shi1; Edmund Webb1; 1Lehigh University
    Depositing nanoparticles from spreading droplets and removing the liquid carrier is a proposed path to fabricating functional materials based on supported 2D nanoparticle arrays. Deterministic engineering of nanoparticle distribution requires thorough understanding of the thermodynamics and associated wetting kinetics of nanosuspension droplets. Quantitative understanding of forces acting on suspended nanoparticles is needed; however, such measurements remain experimentally inaccessible. Herein, we present results from molecular dynamics simulations of nanosuspension droplets spreading on solid surfaces, with emphasis on revealing forces on suspended particles. Pinning of the advancing three phase contact line occurs for low contact angle while de-pinning occurs at higher angles; forces associated with such behaviors are presented. For increasing particle size, a transition from de-pinning to pinning is observed and interpreted in terms of the increasing capillary force between suspended nanoparticles and the solid/liquid/vapor interfaces. At higher nanoparticle concentrations, particle pile up occurs, leading to pinning and non-equilibrium droplet morphology.

11:30 AM  
Acoustic Foucsing for Bulk Assembly of Colloidal Solids from Nanoscale Building Blocks: Tyler Ray1; Rachel Collino1; Leanne Friedrich1; Matthew Begley1; 1University of California, Santa Barbara
    A central challenge to harnessing the unique properties of nanomaterials is the scalable fabrication of bulk, engineered hierarchical materials from nanoscale components. Bottom-up self-assembly offers a promising avenue towards this end, but is limited by diffusive timescales. Increasing assembly speed typically involves the application of external fields (e.g., magnetic, electric) to decrease assembly time vs. diffusional assembly; however, these methods are limited in applicability as a result of material requirements, scalability, or ability to control the assembled structure. This talk presents a “material agnostic” platform for the rapid assembly of nanoscale components into large-scale hierarchical materials using acoustic fields. Coupled with self-assembly, this technique can yield a continuous, unified, and extruded colloidal solid O[1 mm] from nanoscale components as demonstrated with gold nanorods / polystyrene beads, DNA/silica, and Si nanoparticles/block copolymer material systems. This platform offers a compelling approach for rapidly (O[10 s]) assembling and depositing bulk nanomaterial systems.

11:50 AM  
Synthesis and Characterization of Polycaprolactone Nanofibers by Electrospinning Method with Hormone: Cynthia Matos1; Marivalda Pereira2; Rodrigo Oréfice1; 1Federal University of Minas Gerais; 2 Federal University of Minas Gerais
    The implantable systems that have been developed based on polycaprolactone polymer, in the form of contraceptive implants, has gained prominence in researches on new structures. The various studies involving the incorporation of drugs in polymers through electrospinning methods are relatively new and need further exploration. Studies have demonstrated integrity of the drug and it's improved dispersion along the fiber, or more controlled release using nanoparticles. The aim of this article was the production of a biodegradable PCL nanofiber system produced by electrospinning technique, using the acetic acid as a solvent, for controlled release of progesterone. Samples obtained from solutions with different concentrations of PCL, and varying voltage and injection speed parameters, were analyzed after electrospinning. Based on the results, PCL nanofibers were synthetized, using the solvent acetic acid and incorporating the hormone progesterone, by the electrospinning method. Samples with 16%w/w and 23%w/w progesterone showed the best results in all analyzes.