Surface Properties of Biomaterials: Cell-Biomaterial Interactions
Program Organizers: Ryan Bock, SINTX Technologies; Jason Langhorn, DePuy Synthes Joint Reconstruction; Susmita Bose, Washington State University; Amit Bandyopadhyay, Washington State University; Mangal Roy, Indian Institute of Technology-Kharagpur; Venu Varanasi, University of Texas at Arlington

Monday 2:00 PM
September 30, 2019
Room: C121
Location: Oregon Convention Center

Session Chair: Susmita Bose, Washington State University; Amit Bandyopadhyay, Washington State University; Ryan Bock, SINTX Technologies

2:00 PM  Invited
Biological Applications of Nanoscale Janus Particles with Dual Biofunctionalization: Michael Maas1; Reshma Kadam1; Kurosch Rezwan1; 1University of Bremen
    We present a scalable and adaptive platform for the preparation of nanoscale Janus particles with dual biofunctionality. Based on this platform, we designed magnetic Janus nanoparticles which are capable of performing bacterial capture while preventing agglomeration between bacterial cells. The magnetic Janus nanoparticles selectively interact with one type of bacteria from a mixture of bacteria via specific antigen-antibody interactions. In contrast to bacterial capture with isotropically functionalized particles, the bacterial suspensions remain free from cell-nanoparticle-cell agglomerates owing to the passivation coating with polyethylene glycol chains attached to the other half of the Janus particle. This approach is a promising method for rapid and agglomeration-free separation of live bacteria for identification, enrichment and cell counting of bacteria from biological samples. Based on these findings, we are currently also investigating similar dual biofunctionalized Janus nanoparticles for use as markers of cell surfaces, both for bacteria and eukaryotic cells.

2:40 PM  Invited
Interaction between Graphene Surfaces and Extracellular Polymeric Substances of Biofilms: Hideyuki Kanematsu1; Ryoichi Nakagawa1; Dana Barry2; Katsuhiko Sano3; Masatou Ishihara4; Masahito Ban5; Noriyuki Wada1; Nobumitsu Hirai1; Akiko Ogawa1; Takeshi Kogo1; Daisuke Kuroda1; 1National Institute of Technology (KOSEN), Suzuka College; 2Clarkson University / SUNY Canton; 3D & D Corporation; 4National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan; 5Nippon Institute of Technology
    Many researchers and we confirmed that biofilms are very sensitive to biofilm formation. Since biofilms are composed of many kinds of organic polymers and inorganic matters as complicated system, we have to clarify which components would react with graphene and how the reaction would occur depending on the combinations of bacteria, production processes of graphene, experimental conditions etc. In this study, we carried out some experiments to show which components of biofilms would tend to attach to graphene preferentially and how the tendency would change according to the difference among experimental conditions. And we will marshal the experimental data so far, discuss on the sensitivity of graphene for biofilms and propose how we could apply the results to practical applications in the future.

3:20 PM Break

3:40 PM  
The Importance of Base Plate to Barnacle Adhesion: Heonjune Ryou1; Andrew Geltmacher2; Richard Everett3; James Wollmershauser2; Kathryn Wahl2; 1ASEE Postdoc cited at US Naval Research Laboratory; 2US Naval Research Laboratory; 3University of Maryland Baltimore County
    Barnacles adhere to many surfaces by creating a chemically complex interface. For many acorn barnacles, the interface is protected by a hard-calcareous base plate, which may provide further enhancement to the barnacle adhesion. To examine the adhesion enhancing mechanisms of the barnacle base plate, we performed peel tests using adult Balanus amphitrite barnacles attached to flexible polydimethylsiloxane (PDMS) strips. The adhesion force was recorded using a load cell and the peel front was monitored by a digital microscope, simultaneously. Results show that the architecture of barnacle base plate provides means to resist crack initiation and peel propagation. However, the effectiveness of these mechanisms disappeared for barnacles with thicker adhesive layers. This study provides a better understanding of barnacle-surface attachment mechanisms and can aid the development of new anti-fouling coating systems.

4:00 PM  
Time Lapse in Vitro Vibrational Spectroscopic Assessment of Antibacterial Activity of Oxide and Nitride Bioceramics Used in Implantable Medical Devices: Francesco Boschetto1; Ryan Bock2; Bryan McEntire2; Tetsuya Adachi3; Elia Marin3; Wenliang Zhu4; Osam Mazda3; B. Sonny Bal2; Giuseppe Pezzotti1; 1Kyoto Institute of Technology; 2SINTX Technologies; 3Kyoto Prefectural University of Medicine; 4Osaka University
    Time-lapse Fourier Transform Infrared Spectroscopy (FTIR) was used to probe the metabolic response of Gram-positive Staphylococcus epidermidis (S. epidermidis), a major cause of periprosthetic infections, to Zirconia-toughened alumina (ZTA) and silicon nitride (SiN) bioceramics during in vitro exposure. FTIR spectral features reflective of amide and phosphate groups were strongly dependent on substrate type and exposure time. Vibrations associated with amides suggested pH shifts in the bacterial environment toward acidic (ZTA) and alkaline (SiN) values. The acidic pH trend upon exposure to ZTA was correlated to the vibrational behavior of carboxylic acid groups and phosphates, which was not observed during exposure to SiN. Complimented by local pH measurements, a local pH buffering mechanism was spectroscopically observed in situ for SiN. This local pH buffering effect is thought to be at least partially responsible for SiN’s ability to inhibit the spread of common periprosthetic infections.

4:20 PM  
Fe-Mn-Cu Alloy as a Novel Antibacterial Biodegradable Material: Santanu Mandal1; Mangal Roy1; 1Metallurgical and Materials Engineering Department, IIT Kharagpur
    Biodegradable materials are being widely investigated for internal fracture fixation devices in current years. Implants made of pure iron provide good mechanical support but their lower degradation rate is a concern for temporary applications. In this presentation we will discuss about a new antibacterial Fe-Mn-Cu alloy. The hypothesis is that Cu beyond solubility in Fe-Mn, will enhance degradation rate by forming local galvanic cells. In this work, Fe-Mn-(0-10wt%)Cu alloys were prepared by powder metallurgy route. Six times increase in corrosion rate for Fe-Mn-10wt.%Cu alloy was observed compared to Fe-Mn alloy. Broth micro-dilution test showed increased antibacterial activity with Cu addition in Fe-Mn alloy while in vitro cytocompatibility study showed more than 70% cell viability for all alloys. Therefore, Cu alloying in Fe-Mn alloy has high potential to be used for internal fracture fixation devices with enhanced antibacterial activity.

4:40 PM  
Preparation of Anatase-type Titanium Dioxide Having Strong Antibacterial Activity under Dark Conditions: Ken Hirota1; Phuong Nguyen1; Masaki Kato1; Kazuhiko Tsukagoshi1; Atsuki Terabe2; Hideto Mizutani2; 1Doshisha University; 2Sakai Chemical Industry Co., LTD
    Abstract available in late September.

5:00 PM  
Effect of Transition Metal Doping Sites on Biological Properties of Hydroxyapatite: Arjak Bhattacharjee1; Anshul Gupta1; Madhu Verma1; Prem Murugan1; Pradyut Sengupta2; Saravanan Matheshwaran1; Indranil Manna3; Kantesh Balani1; 1IIT Kanpur; 2CSIR-IMMT; 3IIT Kharagpur
    Hydroxyapatite [HA, Ca10(PO4)6(OH)2] is an ideal implant material due to its similarities with human bone. Major cause of hydroxyapatite based implant failure can be attributed to bio film development over the implant surface. Additionally, flexible crystal structure of hydroxyapatite allows substitution of several cations not only on the Ca sites but also on 2b Wyckoff and 12i sites of HA crystal structure. In this work, antibacterial transition metal cations (Zn, Co) are doped on different substitution sites of HA and the substitution sites are confirmed by Rietveld refinement. It has been found that altering the substitution sites results in improved antibacterial efficacy and restricted cytotoxicity of doped HA. Thus this work proves that transition metal doped hydroxyapatite is a suitable candidate for orthopedic implants with tailored biological properties.