Biodegradable Materials for Medical Applications II: Zinc and Iron Implants
Sponsored by: TMS Functional Materials Division, TMS: Biomaterials Committee
Program Organizers: Jaroslaw Drelich, Michigan Technological University; Ehsan Mostaed, Michigan Technological University; Malgorzata Sikora-Jasinska, Michigan Technological University; Jan-Marten Seitz, Syntellix AG; Petra Maier, University of Applied Sciences Stralsund; Norbert Hort, Helmholtz-Zentrum Hereon; Huinan Liu, University Of California Riverside
Tuesday 2:00 PM
February 25, 2020
Room: Vista
Location: Marriott Marquis Hotel
Session Chair: Ehsan Mostaed, Michigan Technological University; Malgorzata Sikora-Jasinska, Michigan Technological University
2:00 PM Keynote
Advances in Zinc and its Alloys as Biodgradable Metals for Medical Applications: Yufeng Zheng1; 1Peking University
The recent works of biomedical zinc and its alloys will be reported in this talk. Firstly the in vivo degradation of pure zinc stent within the blood vessel microenvironment will be presented; secondly several kinds of Zn-based biocomposites aiming for orthopaedic application usage were developed, and their in vivo degradation behavior within bone microenvironment will be reported; thirdly we will show you our works on the development of binary Zn alloys, with over 10 kinds of alloying elements were added into Zn to enhance its mechanical properties and bioactivities; finally we will demonstrate how to use surface modification techniques to adjust the degradation rate and enhance the biocompatibility of pure Zn. All these preliminary in vitro and in vivo studies showed acceptable biodegradability and reasonable biocompatibility in the bone and blood micro-environments for the experimental Zn-based biodegradable metals, and for some alloy systems superior mechanical performance than biomedical Mg alloys.
2:35 PM Invited
Surface Engineering on Zinc for Better Biocompatibility: Donghui Zhu1; 1Stony Brook University
Zinc (Zn) has recently emerged as a novel biodegradable metal thanks to its important physiological roles and promising degradation behavior. However, cytocompatibility of pure Zn is still suboptimal, in part, due to the excessive Zn ions released during degradation. To enhance the biocompatibility of Zn metallics, bioactive coatings including zinc phosphate (ZnP), zinc oxide (ZnO), and zinc hydroxide (Zn(OH)2) were prepared on pure Zn to enhance its biocompatibility. Data shows that ZnP, not ZnO or Zn(OH)2, significantly enhances its biocompatibility. The surface morphology and controlled Zn ion release were shown to be pivotal for the cytocompatibility and antibacterial performance of ZnP coated materials. The decreased Zn ion release and surface morphology significantly enhanced the pre-osteoblast and vascular cell adhesion, viability, and proliferation. Moreover, the micro- and nano-structures of ZnP formed on Zn surface significantly reduced the bacterial adhesion and growth.
3:00 PM Invited
Fe-based Alloys with Extreme Properties for Thinner Absorbable Devices: Sergio Loffredo1; Carlo Paternoster1; Nicolas Giguere2; Maurizio Vedani3; Diego Mantovani1; 1Laval University; 2Quebec Metallurgy Center; 3Mechanics, Polytechnic of Milan
Over the last 50 years, biomaterials, prostheses and implants saved and prolonged the life of millions of humans around the globe. Today, nanotechnology, nanomaterials and surface modifications provides a new insight to the current problem of biomaterial complications, and even allows us to envisage strategies for the organ shortage. In this talk, the potential of nanostructured metallic degradable metals to provide innovative solutions at medium term will be depicted. Focus will be on Fe-based biodegradable metals with exceptional resistance, ductility and elasticity, for pushing innovative applications in vascular surgery. The intrinsic goal of this talk is to present an extremely personal look at how biodegradable metals can impact materials, surfaces and interfaces, and how the resulting unique properties allowed biomedical functional applications to progress, from their introduction, to the promising future that biodegradable metals may or may not hold for improving the quality of the life of millions worldwide.
3:25 PM Invited
Additive Manufacturing of Biodegradable Fe-alloys for Orthopedic Applications: Ali Gokhan Demir1; Danilo Carluccio2; Chun Xu2; Qingsong Ye2; Matthew Dargusch2; Barbara Previtali1; 1Politecnico di Milano; 2University of Queensland
Additive manufacturing (AM) and biomedical devices appear as a natural match for enabling new functional devices with enhanced biological performance, customized to patient specifications. Concerning biodegradable metals, SLM allows for accurate control over the implant geometries and indirectly control over the mechanical properties and degradation behavior. This work focuses on SLM of biodegradable metals and alloys, such as Mg, Fe, Zn and Fe35Mn, and presents a comprehensive overview of the current research on this technology. In particular, SLM of pure Fe and Fe35Mn alloy for orthopedic applications is assessed. Initially, the processability of these materials for high density bulk components as well as thin struts is investigated. Material properties are characterized in terms of microstructure, strength and corrosion behavior. Then, porous bone scaffolds are manufactured and biological performance via in vitro and in vivo testing is presented.
3:50 PM Break
4:05 PM
Different Approaches to Achieving the Appropriate Biodegradability for the Fe-Mn Alloy: Matjaz Godec1; Irena Paulin1; Črtomir Donik1; Jaka Burja1; Matej Hočevar1; Peter Gregorčič2; Aleksandra Kocijan1; 1Institute of Metals and Technology; 2Faculty of Mechanical Engineering
Biodegradable metallic materials are bioactive materials with a temporary support function, which then gradually degrade without a negative effect on the organism. Fe-based alloys possess excellent mechanical properties that can make them ideal candidates for applications where long-term support is needed. The main drawback of Fe-based alloys is their very slow degradation. Also, the very high Young’s modulus of elasticity can be a serious drawback, because human bone has higher value. Different approaches to achieving the appropriate biodegradability will be presented. The research is focused on Fe-Mn alloys, with the aim being to tailor the degradation rate using different approaches, such as chemical alloying, grain-boundary engineering and surface laser texturing, depending on the specific applications. The emerging additive-manufacturing (AM) technology makes it possible to advance the design and production of ideal, topologically porous metals that are suited to temporary implants. The AM process enables freedom of design to achieve bone-mimicking.
4:25 PM
Thermal Treatment of Zn-based Alloys for Vascular Stenting – Effect of Microstructure on Degradation Behavior and In-vivo Response: Malgorzata Sikora-Jasinska1; Ehsan Mostaed1; Roger J. Guillory II1; Jeremy Goldman1; Jaroslaw W. Drelich1; 1Michigan Technological University
Zn-based alloys have become promising materials for bioresorbable vascular stenting due to their favorable degradation rate and adaptability to tissue regeneration. The ability to tune both the corrosion rate and uniformity of stents with a complex geometry is an essential consideration to biosafety of these temporary implants. In our laboratory, high-strength Zn-based multi-element alloys are formulated. In these alloys, intermetallic particles (IMPs) are the important microstructural constituents, influencing their electrochemical properties. By adjusting the IMPs fraction, size and distribution, corrosion behavior of the alloy can be modulated. The presence and characteristics of IMPs are controlled through thermal treatments applied to the alloy. In this presentation, we will show that biocorrosion and biocompatibility of Zn-based alloys correlate with the microstructural evolution induced by thermal treatments.
4:45 PM
Novel Zn-Fe Matrix Nanocomposite as Biodegradable Material: Zeyi Guan1; Jingke Liu1; Xiaochun Li1; 1University of California, Los Angeles
Zinc and zinc alloys as biodegradable metals have been investigated widely for orthopedic and vascular stents due to its ideal bio-corrosion behavior and biocompatibility. Alloying zinc with other elements often results in a compromise in ductility. Here, WC nanoparticles were introduced to the Zn-Fe alloy system aiming to providing additional strengthening and microstructure modification to retain ductility. Thermally stable WC nanoparticles refined the primary grains and modified the FeZn13 precipitate morphology and significantly. Consequently, WC nanoparticles simultaneously enhance the mechanical strength and ductility while maintaining the good corrosion rate and biocompatibility. Overall, this novel Zn-Fe-WC nanocomposite could be potentially applied as a biodegradable material for widespread biomedical applications.
5:05 PM Concluding Comments