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Society for Biomaterials: Student Poster Contest + Rapid Fire: Society for Biomaterials: Student Poster Contest + Rapid Fire
Program Organizers: Roger Narayan, University of North Carolina; Thomas Dziubla, University of Kentucky; Jessica Jennings, University of Memphis; Bob Hastings, Depuy Synthes, J&J

Monday 5:00 PM
October 10, 2022
Room: Ballroom BC
Location: David L. Lawrence Convention Center

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Cancelled
C-10: 3D Printing of Zirconia-alumina Composites via Digital Light Processing: Optimization of the Slurry and the Debinding Process: Barbara Inserra¹; ¹Politecnico di Torino
    Among additive manufacturing technologies, Digital Light Processing (DLP) is regarded as one of the most promising techniques for its high forming precision, excellent surface quality, and fast printing speed. However, the precise composition of the slurry and the optimization of the debinding process, are still challenges that need to be addressed. The present work investigates the printability of zirconia-alumina composites through a stereolithography process. Commercially available 10 mol% CeO2 and 12 mol% CeO2-stabilized zirconia were mechanically mixed with alumina, to provide 11 mol% CeO2-stabilized ZrO2 / 16 vol% Al2O3 composite material. As a result, it was possible to manufacture a > 99 % dense defect-free zirconia-alumina composite with a bending strength of ∼450 MPa. FE-SEM observations showed highly homogeneous microstructures (Fig 1), free from the typical 3D printing flaws, such as delamination between layers and cracks due to the organic matter decomposition.

C-11: Applying Bioactive Glass to Long-term Drug Delivery: Marie Sykes¹; Casey Schwarz¹; ¹Ursinus College
    Ever since bioactive glasses were discovered in 1969, they have traditionally been used for bone repair and regeneration. However, they carry other useful purposes as well, and have shown they have potential in long-term drug delivery. I have characterized Mo-Sci's OL-GL 1756B and proven that with their porous structure they can both absorb solution and release it over a period of a few days.

C-12: Aqueous Chemical Deposition of K0.5Na0.5NbO3 Ferroelectric Thin Films for Biomedical Applications: Ahmed Mohammed; ¹
    K0.5Na0.5NbO3 (KNN) is a lead-free material often lauded for its piezoelectric properties. It is suitable for a wide variety of applications, such as sensors and actuators. Although the material has been extensively studied in bulk ceramic forms, thin films are less well understood. Furthermore, KNN films have not been adapted in industrial settings due to difficulties in synthesizing high-quality samples with high throughput. The most promising fabrication approaches are chemical solution deposition (CSD)techniques which rely on hazardous organic solvents (2-methoxy ethanol). In our approach, we synthesize aqueous solutions at room temperature derived from commercially available niobium, sodium and potassium precursors. This technique allows precise control of stoichiometry, with which we can optimize the functional properties of our films. Moreover, this simple wet chemistry fabrication process is not as energy intensive, expensive, or complex as most thin film deposition techniques which will offer an opportunity for commercialization.

C-13: Blood Coagulation Response to Four Medical Grade Polyurethanes Biomaterials: Lan Nguyen¹; Li-Chong Xu²; Christopher Siedlecki²; ¹Gettysburg College; ²Penn State College of Medicine
    It is important to improve the blood coagulation responses of biomaterials used in cardiovascular devices. Polyurethanes has been widely used in implantable cardiovascular medical devices due to their biocompatibility and excellent mechanical properties. In this study, we characterized the surface properties of four polyurethane biomaterials: MS 0.4, BioSpan S, BioSpan 2F, and CarboSil 20 80A, including surface chemistry, topography, phase structure and wettability. We also studied the ovine, bovine, and human blood plasma coagulation responses to these materials in vitro, as well as the FXII contact activation. Results showed that BioSpan 2F contains high amount of F while other materials consist mostly of Si. An in vitro coagulation assay and a chromogenic assay were performed to show FXII contact activation. These materials demonstrated improved blood coagulation responses compared to the control, there was no significant difference in the coagulation time and the activated FXII yield among the polymers.

C-14: Characterization of the Microstructure, Microhardness and Electrochemical Corrosion Behavior of a NbTiCr Multicomponent Alloy: A First Step Toward an Orthopedic-implant Application: Isabela Dainezi¹; João Passos²; Carlos Rovere¹; ¹Federal University of São Carlos; ²EESC/USP
    Bearing in mind the innovative multicomponent alloy (MCA) concept and the properties required for an orthopedic-implant application, we elaborated a NbTiCr MCA and studied it in the as-cast and hot isostatically pressed conditions. The microstructures, hardness properties, and electrochemical polarization behavior in physiological saline solution (0.9%wt NaCl) were characterized in depth. Our main findings indicated that in both processing conditions the NbTiCr MCA consisted of two phases, namely: a Ti-rich body-centered cubic structure (disordered BCC, A2) matrix with Cr-rich ordered face-centered cubic structure (Laves, C15) precipitates. The NbTiCr MCA presented excellent mechanical strength and microhardness values around 579 HV were obtained for the as-cast condition. Also, in both processing conditions, the NbTiCr MCA exhibited a pitting corrosion resistance superior to that of CoCrMo alloy in 0.9%wt NaCl solution. These preliminary results can be taken as an opportunity to develop new orthopedic-implant alloys based on the NbTiCr MCA composition.

Cancelled
C-15: Controlling Biofilm Formation on Biomaterials by Small Molecules that Interfere with Nucleotide Second Messenger Signaling: Alyssa Ochetto¹; Christopher Siedlecki¹; Li-Chong Xu¹; ¹Penn State College of Medicine
    Interference of bacterial intracellular nucleotide second messenger signaling pathway may allow a way to control pathogenic bacterial adhesion and biofilm formation on biomaterial surfaces. In this study, we identified three small molecules (Nitric Oxide (NO), SP02 and SP03) with potential to interfere with nucleotide messenger signaling in Staphylococcus bacteria that are the most found in microbial infections on medical devices. The analysis of nucleotide molecules shows that NO releasing materials significantly decrease the c-di-GMP levels in both S. epidermidis and S. aureus cells. Furthermore, S. epidermidis also showed a significant decrease in c-di-AMP while no significant changes were observed on S. aureus. A crystal violet staining method shows that both SP02 and SP03 are effective in inhibiting S. epidermidis biofilm formation and enhancing biofilm dispersal. However, a decrease in nucleotide molecule levels were only observed for SP02, suggesting that SP02 can control biofilm formations via interference with nucleotide messenger signaling.

C-16: Decanoic Anhydride-modified Chitosan Membranes Loaded with Bupivacaine and cis-2-decanoic Acid Affect Cytokine Expression of Keratinocytes: Emily Montgomery¹; Zoe Harrison¹; J. Amber Jennings¹; ¹The University of Memphis
    Biomaterials that support the natural inflammatory response and inhibit infections can aid in decreasing the severity of inflammation associated with burn wounds. Electrospun chitosan membranes are promising local drug delivery systems due to their biocompatibility and fibrous nanostructure. Local delivery of cis-2-decenoic acid (C2DA) for infection prevention in combination with an antimicrobial local anesthetic such as bupivacaine (BUP) can address both infection and pain. Chitosan membranes were electrospun using 71% DDA chitosan in 70:30% (v/v) trifluoroacetic acid to dichloromethane. Membrane discs 1 cm in diameter were treated in 50:50 pyridine to decanoic anhydride (DA). DA-modified membranes were loaded with BUP, C2DA, or a combination at low, medium, and high concentrations. Membranes were UV sterilized and directly exposed to normal human epidermal keratinocytes (NHEK) for 24 and 72 hours, and cytokines IL-12 and IL-10 in supernatants were measured using ELISA. Results indicate that C2DA combined with BUP promotes anti-inflammatory cytokine release.

C-17: Effect of Strain on the Thermoelectric Properties of Epitaxial La0.8Sr0.2CoO3 Thin Films: Mohammad El Loubani¹; Gene Yang¹; David Hill¹; Dongkyu Lee¹; ¹University of South Carolina
    ABO3 oxides have been highlighted as an alternative material for thermoelectric (TE) generators, which convert heat energy into electricity. The TE efficiency is mainly dependent on the intrinsic properties such as the thermopower and electrical conductivity of oxides, where oxygen defects play a determining role in such properties. In this regard, using epitaxial strain induced by the lattice mismatch between the film and the substrate is a promising approach to modulate the concentration of oxygen defects controlling the TE efficiency. However, the influence of strain on the thermoelectric properties of oxide materials is not fully understood. In this study, using epitaxial La0.8Sr0.2CoO3 thin films as a model system, we investigate the effect of strain-controlled oxygen defects on the thermoelectric properties of oxides. Films with zero-, tensile-, compressive strain are evaluated in terms of oxygen vacancies, thermopower, and electrical conductivity. We show that strain can effectively control the TE efficiency.

Cancelled
C-18: Engineering 18F-Thermo-Responsive Assembled Protein through Bioconjugation to a Bimodal Fluorescent/PET Probe for Theranostic Purposes: Aparajita Bhattacharya¹; ¹NYU
    Theranostic agents are being developed for their ability to diagnose various diseases and improve therapeutic delivery. Traditional drug delivery has been inefficient due to factors such as drug insolubility, tissue indiscriminate cytotoxicity, their inability to stimulate release and their lack of direct monitoring. Recently, we have engineered a protein-based theranostic agent fluorinated thermo-responsive assembled protein (F-TRAP) bearing fluorinated amino acids. F-TRAP self-assembles into micellar structures and consist of hydrophobic pores capable of encapsulating the chemotherapeutic drug molecule, doxorubicin. Moreover, F-TRAP is traceable via 19F magnetic resonance imaging (MRI). To increase the sensitivity for imaging, we are developing a positron emission tomography (PET) visible agent, 18F-TRAP. We employ residue-specific incorporation of an azide-bearing methionine analog, azidohomoalanine to give rise to clickable azide-functionalized TRAP that can be subsequently conjugated to a 18F bearing alkyne analog of boron-dipyrromethene (BODIPY) dye, imparting it an ability to be used as a dual modality PET probe.

C-19: Polymerized High Internal Phase Emulsions Derived from Photocurable Polycaprolactone for Tissue Engineering Applications: Sierra Kucko¹; Timothy Keenan¹; ¹Alfred University
    Polycaprolactone (PCL) is a polymer of the poly(α-hydroxyester) variety that is utilized extensively in tissue engineering, as it is approved for human clinical use. PCL can be functionalized with methacrylate end groups to render it photocurable, lending itself to numerous fabrication techniques. Polymerized high internal phase emulsions (polyHIPEs) produce highly porous and interconnected scaffolds that are advantageous for tissue regeneration purposes. PolyHIPEs developed with such photocurable PCL can be cured almost instantaneously to create tailorable scaffolds. Polymer chemistry reactions are described, and chemical species of the resulting product are confirmed with Raman and ATR-FTIR spectroscopy. Porosity and interconnectivity are demonstrated with SEM imaging.

C-20: Understanding of Interface-property Relationships of Vertically Aligned Mixed Ionic Electronic Conductor-ionic Conductor Heterostructures: Gene Yang¹; Mohammad El Loubani¹; Dongkyu Lee¹; ¹University of South Carolina
    To develop oxide-based energy applications such as solid oxide fuel cells, the sluggish reaction kinetics at the electrode needs to be overcome. Among various approaches to improve the electrode performance, oxide multilayer thin films consisting of mixed ionic-electronic conducting oxides (MIEC) and ionic conductors have recently attracted increasing attention since both ion conduction and electrocatalytic activity can be enhanced by interfacial strain. However, nanoscale thickness required for maintaining interfacial strain along the lateral direction is impractical. Thus, new design concepts are required to realize heterostructures with micron-scale thickness for commercial applications. In this work, a combination of MIECs and Gd-doped CeO2 (GDC) is used in the form of vertically aligned heterostructures to investigate the relationships between structure, interface, and material property. Our finding will provide a rational design strategy to precisely control the strained interfaces facilitating the development of high-performance electrochemical energy applications.

C-21: Villi Inspired Elastomeric Interlocking Device for Intestinal Retentive Applications: Durva Naik¹; ¹Carnegie Mellon University
    Achieving prolonged retention of medical devices in the small intestine remains a significant clinical challenge. Here, we investigate mechanical interlocking between high-aspect-ratio elastomeric microposts and villi to develop intestinal retentive platforms. Preliminary assessment of this strategy is done via FEA based mechanical simulations. Interlocking efficiency of microposts is characterized as a function of their moduli and extent of overlap between the micropost and villus. Further, we analyze interlocking between devices laminated with microposts and villi to evaluate their efficacy to resist peristaltic stresses by varying the design and material properties. Simulations are then validated by performing lap-shear tests between artificial villi and devices fabricated by DLP 3D printing in tandem with a multi-step replica molding technique. We demonstrate that these devices effortlessly consolidate within the villi under contractile pressure and resist peristaltic shear via mechanical interlocking. This study presents a novel, compliant and non-penetrative strategy to develop intestinal retentive platforms.

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