Biological Materials Science: Biological Materials Science Poster Session
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Biomaterials Committee
Program Organizers: Po-Yu Chen, National Tsing Hua University; Francois Barthelat, McGill University; Michael Porter, Clemson University; Steven Naleway, University of Utah

Tuesday 6:00 PM
February 28, 2017
Room: Hall B1
Location: San Diego Convention Ctr

H-10: Effect of Cu Content on the Antimicrobial Properties of Copper Alloys: Monika Walkowicz1; Piotr Osuch1; Beata Smyrak1; Andrzej Mamala1; Tadeusz Knych2; Anna Rozanska1; Agnieszka Chmielarczyk2; Dorota Romaniszyn2; Malgorzata Bulanda2; 1AGH University of Science and Technology; 2Jagiellonian University Medical College
    Although the antimicrobial properties of copper have been known to cultures all around the world for many centuries, this phenomenon is currently receiving renewed attention, and copper-based touch surfaces are currently being installed in healthcare facilities all over the world, contributing to reduction of nosocomial infections. Application of copper-based touch surfaces often requires using of copper alloys, in which the content of bacteria killing-copper ions at the surface is connected not only with the copper content within alloy, but also with the oxygen affinity of other alloy components, which can significantly translate into antimicrobial efficacy of particular commercial copper alloys. Research contain results of microbiological tests with common microbes, such as S.aureus and E.coli on various commercial copper alloys. The project was financially supported by The Polish National Centre for Research and Development (PBS3/A9/32/2015)

H-11: Effect of the Oxidation of Copper and its Alloys on the Antimicrobial Efficacy of Touch Surfaces: Monika Walkowicz1; Piotr Osuch1; Beata Smyrak1; Andrzej Mamala1; Tadeusz Knych1; Anna Rżańska2; Agnieszka Chmielarczyk2; Dorota Romaniszyn2; Malgorzata Bulanda2; 1AGH University of Science and Technology; 2Jagiellonian University Medical College
    Over the last years there has been a renaissance of the use of copper for touch surfaces, as an effective weapon in the fight against infections caused by touch-transmitted, antibiotic resistant microbes. Products intended for contact with human skin, made from copper and its alloys, especially due to corrosive effect of human sweat, are prone to oxidation. It can lead to change in product appearance over time, which in turn gives rise to questions on the impact of human sweat-induced surface oxidation on antimicrobial efficacy of copper touch surfaces. Within our research samples of copper and some of its commercial alloys were subjected to oxidation in controlled laboratory conditions. Oxide layers were characterized in terms of its thickness, chemical composition, roughness and wettability. Research were completed with results of microbiological tests with common microbes. The project was financially supported by The Polish National Centre for Research and Development - PBS3/A9/32/2015

H-12: Investigating Biochemical Constituents of Cymbopogon Citratus Leaf: Prospects on Total Corrosion of Concrete Steel-rebar in Acidic-Sulphate Medium: Joshua Okeniyi1; Elizabeth Okeniyi1; Olubanke Ogunlana1; Taiwo Owoeye1; Oluseyi Ogunlana2; 1Covenant University, Ota, Nigeria; 2Crawford University, Igbesa, Nigeria
    In this paper, the biochemical constituents of Cymbopogon citratus leaf were investigated by atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FT-IR) and phytochemical screening analyses for assessing its steel-rebar corrosion-protection prospects. AAS results showed that the leaf contained Fe = 4,641.025 μg/g, Mn = 849.5069 μg/g, Cu = 171.045 μg/g, Pb = 13.2938 μg/g, Ni = 11.5187 μg/g, Cd = 4.9310 μg/g, but Cr = 0.0 μg/g. FT-IR indicates the leaf-extract contained S-, N-, O-containing heteroatoms and aromatic compounds, which are rich in π-electrons and that are known to inhibit steel-rebar corrosion. Phytochemical screening results showed that Cymbopogon citratus leaf-extract contains tannins, phlobatannins, saponins, glycosides, flavonoids, steroids and terpenoids. Macrocell corrosion tests, as per ASTM G109-99a, showed that the plant reduced total corrosion in 0.5 M H2SO4-immersed steel-reinforced concrete samples. These indicated positive prospects of Cymbopogon citratus as an eco-friendly inhibitor of steel-reinforcement corrosion in concretes designed for acidic sulphate service-environment.

H-14: Structure-Property Relations of the Ironclad Beetle (Zopherus nodulus haldemani) Exoskeleton: Vina Nguyen1; Parker Berthelsen1; Hongjoo Rhee1; Melanae Garrett1; Mark Horstemeyer1; Lakiesha Williams1; Jun Liao1; Robert Moser2; Rajkumar Prabhu1; 1Mississippi State University; 2U.S. Army Engineer Research and Development Center
    In this study, structure-property relationships in the ironclad beetle (Zopherus nodulus haldemani) exoskeleton are quantified for impact-resistance. Impact resistant materials require constant innovation. In response, arthropod exoskeleton are researched to determine new design strategies. Determination of structure-property relationships in ironclad beetle exoskeletons provides a means to develop bio-inspired materials to be applied for impact-resistant material applications. Experimental study required examination of the microstructure through scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDS) and measurement of the mechanical properties through indentation testing. The exoskeleton is a multi-layer material consisting of chitin in the form of a Bouligand structure. EDS showed the existence of elements such as those comprising chitin, calcium, manganese, and zinc. Mechanical testing was completed on the elytra and pronotum of the exoskeleton on the normal surfaces and on cross-sections. Future studies will involve the design of a novel bio-inspired material based on insights gained from ironclad beetle exoskeletons.

H-15: Synthesis and Characterization of Mesoporous Forsterite/Magnesium Oxide Composite Powder: Seyed Mehdi Mirhadi1; Fariborz Tavangarian2; 1Shahreza Branch, Islamic Azad University; 2Penn State Harrisburg
    Forsterite with the chemical formula Mg2SiO4 has attracted the attention of many scientists as a bioceramic in the recent decades. Si and Mg components of forsterite play a vital role in the growth and mineralization of the bones in human bodies. Silicon involves in the early stage of bone calcification in physiological conditions. Furthermore, it was found that silicon deficiency in rats resulted in skull deformations. Magnesium also plays a significant role in the bone fragility, bone-growth, osteoblastic activities and degradation of hydroxyapatite crystals. In this paper, mesoporous forsterite powder was synthesized by a sol-gel method. X-ray diffractometry (XRD), and Fourier transform infrared spectroscopy (FT-IR) were utilized to characterize the forsterite powder. The mesoporous structure can boost cell growth, bioactivity, and biological fixation in bone defect. The results showed that mesoporous forsterite/magnesium oxide composite powder can be synthesized after sintering the dried gel at 610 C for 6h.

H-16: The Protective Scales of Atractosteus Spatula and the Production of a Bioinspired Armor: Vincent Sherman1; Nicholas Yaraghi2; Marc Meyers1; David Kisailus2; 1University of California, San Diego; 2University of California, Riverside
    The Atractosteus spatula is a fish which has existed for over 100 million years due to its scales which provide a highly resilient armor. We present an in-depth investigation of the protective function of the scales and identify features which lead to their resistance to failure. Microstructural features include crack inhibiting mineral decussation in the external ganoine layer, mineral crystals which deflect cracks in the bony region, and sawtooth ridges along the interface between the two scale layers which direct cracks away from the intrinsically weak interface. The geometry of the scales is shown to retain full coverage while conforming to physiologically required strain and flexibility in spite of minimal overlap between adjacent scales via a process in which adjacent rows of scales slide and reorient. Key features of the scale morphology are replicated in a simplified bioinspired model, and subsequently manufactured form zirconia.

H-17: Microstructural Characterization of Freeze-casted Al2O3 Scaffold: Guan-Lin Liu1; Yi-Ting Liao1; Joe-Ming Chang1; Hsiao-Ming Tung1; 1Institute of Nuclear Energy Research
    The purpose of this study is to investigate the effects of cooling rates on the microstructure of Al2O3 Scaffold prepared by a freeze-casted process. The cooling rates were 2, 5 and 8oC/min. Pore size distribution and porosity of porous Al2O3 were examined using mercury porosimetry. Micro–computed tomography (Micro-CT) was used to exhibit the inner structure of porous Al2O3. The experimental results show that the average pore size and porosity increase with increasing cooling rates. Large pores appear to be located near the center of Al2O3 scaffold.

H-18: Two-step Sintering Effects on the Microstructure and Mechanical Properties of Forsterite Scaffolds: Fariborz Tavangarian1; Lindsay Childs2; Guoqiang Li3; Dakota Wooten2; Bryant Cornwell2; 1Penn State Harrisburg; 2Morehead State University; 3Louisiana State University
    In this study, we evaluate the effects of two-step sintering on the microstructure, compressive strength and porosity of forsterite scaffolds for tissue engineering application. Forsterite slurry was prepared and pre-cut foams were immersed in the slurry for 1h. The saturated foams were then annealed at various times and temperatures using the two-step sintering method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The results showed that two-step sintering method can prevent the grain growth which occurs during the sintering process of scaffolds at high temperatures and subsequently provides higher compressive strength compared to conventional sintering method. The first step of the sintering process, which occurs at a higher temperature, is to provide initial binding through sintering and localized melting between the contact surfaces of adjacent grains and the second step at a lower temperature is to strengthen and complete the sintering process.