Biological Materials Science: Student Poster Competition
Sponsored by: TMS Functional Materials Division, TMS Structural Materials Division, TMS: Biomaterials Committee
Program Organizers: Steven Naleway, University of Utah; Jing Du, Pennsylvania State University; Rajendra Kasinath, DePuy Synthes (Johnson and Johnson); David Restrepo, University of Texas at San Antonio
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
Session Chair: Steven Naleway, University of Utah; Jing Du, Pennsylvania State University; Rajendra Kasinath, DePuy Synthes (Johnson and Johnson); David Restrepo, University of Texas at San Antonio
B-13: 3D Printed Models of the Arrangement of Components in Two-phase Composites: Frances Su1; Fereshteh Sabet2; Katherine Tang1; Sean Garner1; Michael Tolley1; Iwona Jasiuk2; Joanna McKittrick1; 1University of California, San Diego; 2University of Illinois at Urbana-Champaign
Bone is a biological composite with mineral and collagen phases. To better understand the nanostructural arrangement of the phases on the mechanical properties, the effects of phase arrangement using 3D printed samples of simplified models of interpenetrating phases, matrix-inclusion, and discontinuous phase composites were examined. Samples were printed with a stiff polymer (VeroClear) to represent the mineral phase and a soft polymer (TangoBlack) to represent the collagen phase. Analysis of uniaxial compression stress-strain behavior showed that samples with a stiff continuous phase and soft inclusions had the highest stiffness, while samples with discontinuous phases exhibited the lowest stiffnesses. Moreover, these data demonstrated that stiff-inclusion interpenetrating composites have similar stiffnesses to soft-inclusion interpenetrating composites. Samples were also printed in varying scales and revealed that the stiffness and strength of the composites decreased as size decreased. This research is supported by the National Science Foundation (DMR-1507978).
B-14: Biodegradable 3D Fibrous Scaffold with Co-axially Aligned Carbon Nanotubes for Directional Regeneration of Peripheral Nerves: Souvik Ghosh1; Swati Haldar1; Sumeet Gupta2; Ankita Bisth1; Samrat Chauhan2; Partha Roy1; Debrupa Lahiri1; 1Indian Institute of Technology, Roorkee; 2Maharshi Markandeshwar University
Connecting nerve sprouts and Büngner bands arising respectively, from the anterior and distal ends of a nerve gap is critical for its bridging. However, inefficient reconnection between nerve sprouts and Büngner bands causes incomplete axonal regeneration. Nerve conduits partially alleviate this situation. Electrical impulses stimulate directional growth of nerves. But provision for electrical cues is absent in available conduits. Design, fabrication, characterization and functional validation of a novel biodegradable conductive electrospun scaffold with nanfibers co-axially re-inforced with MWCNTs is described here. Anisotropic conductivity in the scaffold is provided by aligning the reinforced nanofibers while spinning. The scaffold could regenerate injured rat nerve completely and restored lost motor function to the injured limb. The electrical conductivity of the scaffold facilitated Wallerian degeneration and guided of nerve sprouts towards the freshly formed Büngner bands. Therefore, the reported scaffold is a peerless recourse among neural regenerative templates known thus far.
B-15: Electrochemical Evaluation of Ti-13Nb-13Zr-B Alloys for Knee Implants: Thu Nguyen1; Jacob Giacomi1; Vilupanur Ravi1; 1California Polytechnical State University, Pomona
To increase the longevity and to optimize the performance of biomedical implants, a new class of β-titanium alloys, specifically Ti-Nb-Zr (TNZ) is being explored. TNZ alloys demonstrate advantageous properties including non-toxicity, biocompatibility and low elastic modulii. Moreover, previous studies have shown that the addition of trace amounts of boron (0-1 wt.%) in titanium alloys increases the tensile strength and corrosion resistance of the alloys. However, the corrosion behavior of boron-containing TNZ alloys is yet to be investigated. Therefore, the objective of this study was to investigate the corrosion behavior of Ti-13Nb-13Zr (wt %) (Ti-1313) with 0.01, 0.1 to 1 wt% boron additions. Cast billets of TNZ alloys were hot isostatically pressed to reduce internal porosity. Materials were characterized using optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The electrochemical characterization was carried out in accordance with ASTM standards.
B-16: Fracture Mechanisms of Epoxy-alumina Composites: Jiacheng Gao1; Ruyi Man1; Yuyang Wang1; Yichun Tang1; Kangning Su1; Michael Hillman1; Jing Du1; 1Penn State University
Polymer-ceramic composite materials are commonly used in biomedical applications, such as drug delivery, tissue engineering, and bone repair. In our prior work, epoxy-alumina composites were used in the bio-inspired design of functionally graded dental materials. This work presents the results of an experimental study of the fracture behaviors of epoxy-alumina composites. Epoxy-alumina composite specimens are made by mixing epoxy resin with alumina particle fillers of various volume fractions. Fracture toughness values are then measured using three-point bending test on single-edge notched bend (SENB) specimens. The three-point bending tests are also paused to allow micro- X-ray computed tomography (micro-CT) scans of the specimen. The propagation of fracture paths is revealed in the micro-CT image stacks. The effects of ceramic filler volume fractions on the fracture mechanisms are studied, and the implications of the results on the design of robust composite materials are discussed for future design of robust biomaterials.
B-17: Microsphere Calcium Phosphate Cements to Improve Injectability and 3D-printability of Dental Biomaterials: Tony Yin1; Krista Carlson1; Steven Naleway1; 1University of Utah
Self-setting calcium phosphate cements (CPCs) are successfully used in various dental and orthopedic applications for bone repair. However, CPCs have shown poor injectability due to phase separation during extrusion. As such, there is a need to improve the delivery of CPCs without negatively impacting the setting time and mechanical properties. To solve this issue, microspheres made from calcium phosphate powder were used to create an injectable CPC. CPC injectability, setting time, and mechanical strength were tested by comparing CPCs made from either microspheres and irregularly shaped particles. The results of this provided a microsphere CPC with improved injectability without detriment to the mechanical properties. These results were further explored in applications of 3D-printing, where CPCs were successfully extruded as a bio-ink into complex structures. With improved injectability and potential in 3D-printing, microsphere CPCs can be used as bone grafts to improve clinical surgeries where minimally-invasive techniques are desired.
B-18: Modulation of Neurogenic Differentiation by Reinforcement of Polymeric Scaffolds with Different Carbon Nanofillers: Souvik Ghosh1; Swati Haldar1; Viney Kumar1; Partha Roy1; Debrupa Lahiri1; 1Indian Institute of Technology, Roorkee
Regeneration and differentiation of neuronal cells are required for treating various neurological disorders and can be achieved through neural tissue engineering.Electrical impulses are needed for neural regeneration and differentiation.Available options either do not have the provision for electrical cues or they require high end techniques for synthesis.This study approaches towards synthesis of inexpensive and easy to tailor neural scaffold.In this study the fabrication and characterization of composite scaffold reinforced with either multi-walled carbon nanotubes (MWCNTs) or graphene nanoplatelets (GNPs) was described.These reinforcements were aligned along particular directions to impart anisotropic conductivity to the scaffolds.The scaffolds promoted cell differentiation in the presence of electrical field. Interestingly, structural differences of the carbon nanofillers dictated the morphology of growing neurons: elongated in case of MWCNTs and astral for GNPs. Differences achieved in the morphology of the neurons through different nanofillers create options of using these scaffold in both PNS and CNS tissue engineering.
B-19: Structural and Mechanical Characterization of Quasi-indestructible Armillaria ostoyae Rhizomorphs: Debora Lyn Porter1; Alexander Bradshaw2; Bryn Dentinger2; Steven Naleway1; 1The University of Utah Department of Mechanical Engineering; 2The University of Utah Department of Biology
Armillaria ostoyae (Romagn.) Herink is a pathogenic species of fungus found across the globe that uses exploratory, root-like structures called rhizomorphs to seek out new sources of nutrition. These rhizomorphs, which do not react to traditional fungal control methods, infect crops and forest vegetation, resulting in significant economic and ecological losses. Little is known about the structure or mechanics of these quasi-indestructible Armillaria components. We employ imaging techniques, mechanical testing, heat and pH treatments to characterize the structure and strength of the rhizomorphs. Imaging, hardness and tensile strength testing, are used to track the changes that occur to the structure and affect the mechanical properties of the rhizomorphs after undergoing heat and pH treatment. This characterization and understanding of the rhizomorph’s intricate structure will serve as a model for bioinspired designs with high tensile strength, and also provide new insight on how A.ostoyae can effectively be managed.
Cancelled
B-20: The Effect of the Addition of Cobalt Powder on Compressive Properties of Porous Titanium as Bone Substitute Materials: Feng Zhang1; Guibao Qiu1; Hanghang Zhou1; Tengfei Lu1; 1Chongqing University
Titanium foam considered as a potential bone substitute because of its good biocompatibility. In the preparation of porous titanium, titanium and cobalt can be distributed evenly in the matrix of porous titanium alloy with cobalt as an alloy element. Such intermetallic compounds possess better mechanical properties.the compressive properties of porous titanium with different cobalt powder addition on it were studied when the volume fraction of urea was 60%, the sintering temperature was 1100℃, and the holding time was 1.5 hours. The results show that with the increase of cobalt content, the compressive properties of porous titanium-cobalt alloy is obviously improved compared with pure porous titanium. When the cobalt content is 10Wt%, the yield strength of the material reaches the maximum value of 363.76MPa.
B-21: Using Microspheres to Understand the Effect of Particle Geometry in Freeze Casting: Sierra Freitas1; Lauren Kochaver1; Krista Carlson1; Steven Naleway1; 1University of Utah
Porous scaffolds are used in many engineering applications such as biomedical implants, aerospace composites, and radioactive waste filters. Their fabrication, specifically the use of irregularly shaped particle frit as a base material, often result in scaffolds that fail to give the structural properties necessary to fulfil their target applications. This project aims to use microspheres as a base material to produce porous scaffolds with microstructures that produce desirable properties when compared to irregular shaped frit. These scaffolds are fabricated using freeze casting, a technique that employs ice crystals to template porous ceramic scaffolds and will be compared to the mechanical properties and microstructure of scaffolds fabricated with irregular shaped frit. Using microspheres produces porous scaffolds with microstructures that have desirable properties when compared to irregular shaped frit. These microsphere-based freeze cast scaffolds can be used to promote cell growth and as filter materials to pick up radioactive waste.