Special Issue "Bioabsorbable and Permanent Materials for Highly Loaded Implants"

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Biomaterials".

Deadline for manuscript submissions: 30 June 2021.

Special Issue Editor

Dr. Bernhard Mingler
E-Mail Website
Guest Editor
Competence Unit Biomedical Systems, Center for Health & Bioresources, AIT Austrian Institute of Technology GmbH, Viktor Kaplan Strasse 2, 2700 Wiener Neustadt, Austria
Interests: Metallic biomaterials and their characterization; microstructure and mechanical properties of light metals; bioabsorbable magnesium and zinc alloys and their in vitro and in vivo behaviour; pure titanium and titanium alloys; severe plastic deformation; equal channel angular pressing (ECAP); ultrafine grained and nanocrystalline metals; application of metallic biomaterials for medical devices such as implants and prostheses

Special Issue Information

Dear Colleagues,

Factors like the ongoing significant demographic change with an increasing number of elderly people who want to be active as long as possible, new sports with high risk for injury, physical inactivity, overweight, and allergies trigger an enormous demand from society and industry for innovative biomaterials with superior properties. These biomaterials include permanent ones, like pure titanium or titanium alloys, as well as bioabsorbable ones, like magnesium alloys, all providing the necessary stabilizing function in the healing time after implantation. Especially bioabsorbable implants attract high medical interest, as they degrade without any harm to the human body after fullfilling their function. These materials offer, therefore, the invaluable advantage that burdensome and costly explantations can be omitted.

Innovations and further improvements are required, especially for highly loaded implants including orthopedic, trauma, craniomaxillofacial, cardiovascular, dental as well as reconstruction implants. In line with these demands, the main focus of this Special Issue is to collect scientific contributions dealing with the development of biomaterials with improved and unique mechanical properties for applications in highly loaded implants, longer implant lifespans and implant miniaturization while maintaining strength.

As an example, with regard to bioabsorbable implants, low-alloyed Mg–Zn–Ca alloys are very promising materials due to their high biocompatibility and slow and homogenous degradation behaviour. However, their strength is limited due to only very weak solid solution and precipitation hardening. Therefore, the low strength of lean Mg-alloys has to be compensated by systematic alloy development and thermomechanical processing using conventional and severe plastic deformation methods. Scientific contributions to other bioabsorbable metals, such as iron and zinc alloys, as well as to nonmetallic materials are also very welcome.

There is also a great need for research to improve the mechanical properties of permanent implant materials. In general, strength improvements combined with high ductility enable materials to withstand higher loads or implants to be miniaturized under a given load. One research goal in this context is, for example, the following one: In order to be able to replace the widely used high-strength Ti–6Al–4V alloy, containing the problematic alloying elements aluminium and vanadium, the strength of the much more biocompatible pure titanium has to be increased to a similar level using suitable processing methods.

Finally, as the biointerface plays a critical role in implant–tissue interactions, contributions to implant coating strategies and their effects on the implant biofunctionality and corrosion behaviour are equally highly welcome. 

It is my pleasure to invite you to contribute your research articles, communications or reviews to this Special Issue.

Dr. Bernhard Mingler
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Bioabsorbable and permanent biomaterials
  • Mg alloys
  • Pure titanium, titanium alloys
  • Highly loaded implants
  • Mechanical properties
  • Severe plastic deformation
  • Biofunctional coatings

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Comparative Study of the Structure, Properties, and Corrosion Behavior of Sr-Containing Biocoatings on Mg0.8Ca
Materials 2020, 13(8), 1942; https://doi.org/10.3390/ma13081942 - 20 Apr 2020
Cited by 5 | Viewed by 847
Abstract
A comparative analysis of the structure, properties and the corrosion behavior of the micro-arc coatings based on Sr-substituted hydroxyapatite (Sr-HA) and Sr-substituted tricalcium phosphate (Sr-TCP) deposited on Mg0.8Ca alloy substrates was performed. The current density during the formation of the Sr-HA coatings was [...] Read more.
A comparative analysis of the structure, properties and the corrosion behavior of the micro-arc coatings based on Sr-substituted hydroxyapatite (Sr-HA) and Sr-substituted tricalcium phosphate (Sr-TCP) deposited on Mg0.8Ca alloy substrates was performed. The current density during the formation of the Sr-HA coatings was higher than that for the Sr-TCP coatings. As a result, the Sr-HA coatings were thicker and had a greater surface roughness Ra than the Sr-TCP coatings. In addition, pore sizes of the Sr-HA were almost two times larger. The ratio (Ca + Sr + Mg)/P were equal 1.64 and 1.47 for Sr-HA and Sr-TCP coatings, respectively. Thus, it can be assumed that the composition of Sr-HA and Sr-TCP coatings was predominantly presented by (Sr,Mg)-substituted hydroxyapatite and (Sr,Mg)-substituted tricalcium phosphate. However, the average content of Sr was approximately the same for both types of the coatings and was equal to 1.8 at.%. The Sr-HA coatings were less soluble and had higher corrosion resistance than the Sr-TCP coatings. Cytotoxic tests in vitro demonstrated a higher cell viability after cultivation with extracts of the Sr-HA coatings. Full article
(This article belongs to the Special Issue Bioabsorbable and Permanent Materials for Highly Loaded Implants)
Show Figures

Figure 1

Open AccessFeature PaperArticle
Surface Analysis of Biodegradable Mg-Alloys after Immersion in Simulated Body Fluid
Materials 2020, 13(7), 1740; https://doi.org/10.3390/ma13071740 - 08 Apr 2020
Cited by 2 | Viewed by 885
Abstract
Two binary biodegradable Mg-alloys and one ternary biodegradable Mg-alloy (Mg-0.3Ca, Mg-5Zn and Mg-5Zn-0.3Ca, all in wt%) were investigated. Surface-sensitive X-ray photoelectron spectroscopy analyses (XPS) of the alloy surfaces before and after immersion in simulated body fluid (SBF) were performed. The XPS analysis of [...] Read more.
Two binary biodegradable Mg-alloys and one ternary biodegradable Mg-alloy (Mg-0.3Ca, Mg-5Zn and Mg-5Zn-0.3Ca, all in wt%) were investigated. Surface-sensitive X-ray photoelectron spectroscopy analyses (XPS) of the alloy surfaces before and after immersion in simulated body fluid (SBF) were performed. The XPS analysis of the samples before the immersion in SBF revealed that the top layer of the alloy might have a non-homogeneous composition relative to the bulk. Degradation during the SBF immersion testing was monitored by measuring the evolution of H2. It was possible to evaluate the thickness of the sample degradation layers after the SBF immersion based on scanning electron microscopy (SEM) of the tilted sample. The thickness was in the order of 10–100 µm. The typical bio-corrosion products of all of the investigated alloys consisted of Mg, Ca, P and O, which suggests the formation of apatite (calcium phosphate hydroxide), magnesium hydrogen phosphate hydrate and magnesium hydroxide. The bioapplicability of the analyzed alloys with regard to surface composition and degradation kinetics is discussed. Full article
(This article belongs to the Special Issue Bioabsorbable and Permanent Materials for Highly Loaded Implants)
Show Figures

Figure 1

Open AccessFeature PaperArticle
Exceptional Strengthening of Biodegradable Mg-Zn-Ca Alloys through High Pressure Torsion and Subsequent Heat Treatment
Materials 2019, 12(15), 2460; https://doi.org/10.3390/ma12152460 - 02 Aug 2019
Cited by 9 | Viewed by 1353
Abstract
In this study, two biodegradable Mg-Zn-Ca alloys with alloy content of less than 1 wt % were strengthened via high pressure torsion (HPT). A subsequent heat treatment at temperatures of around 0.45 Tm led to an additional, sometimes even larger increase in [...] Read more.
In this study, two biodegradable Mg-Zn-Ca alloys with alloy content of less than 1 wt % were strengthened via high pressure torsion (HPT). A subsequent heat treatment at temperatures of around 0.45 Tm led to an additional, sometimes even larger increase in both hardness and tensile strength. A hardness of more than 110 HV and tensile strength of more than 300 MPa were achieved in Mg-0.2Zn-0.5Ca by this procedure. Microstructural analyses were conducted by scanning and transmission electron microscopy (SEM and TEM, respectively) and atom probe tomography (APT) to reveal the origin of this strength increase. They indicated a grain size in the sub-micron range, Ca-rich precipitates, and segregation of the alloying elements at the grain boundaries after HPT-processing. While the grain size and segregation remained mostly unchanged during the heat treatment, the size and density of the precipitates increased slightly. However, estimates with an Orowan-type equation showed that precipitation hardening cannot account for the strength increase observed. Instead, the high concentration of vacancies after HPT-processing is thought to lead to the formation of vacancy agglomerates and dislocation loops in the basal plane, where they represent particularly strong obstacles to dislocation movement, thus, accounting for the considerable strength increase observed. This idea is substantiated by theoretical considerations and quenching experiments, which also show an increase in hardness when the same heat treatment is applied. Full article
(This article belongs to the Special Issue Bioabsorbable and Permanent Materials for Highly Loaded Implants)
Show Figures

Graphical abstract

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Exceptional strengthening of biodegradable Mg–Zn–Ca alloys through high pressure torsion and subsequent heat treatment
Authors: All the authors’ names and emails:
Jelena Horky 1,2, Abdul Ghaffar 1,3, Katharina Werbach 1, Bernhard Mingler 2,  Stefan Pogatscher 4,5, Robin Schäublin 4, Daria Setman 1, Peter J. Uggowitzer 4, Jörg F. Löffler 4 and Michael J. Zehetbauer 1
Affiliations:
1 Physics of Nanostructured Materials, Faculty of Physics, University of Vienna, 1090 Vienna, Austria; [email protected] (J.H.); [email protected] (A.G.); [email protected] (K.W.); [email protected] (D.S.); [email protected] (M.J.Z.)
2 Center for Health & Bioresources, Biomedical Systems, AIT Austrian Institute of Technology GmbH, 2700 Wiener Neustadt, Austria; [email protected]
3 Department of Physics, GC University, 54000 Lahore, Pakistan
4 Laboratory of Metal Physics and Technology, Department of Materials, ETH Zurich, 8093 Zurich, Switzerland; [email protected] (S.P.); [email protected] (R.S.); [email protected] (P.J.U.); [email protected] (J.F.L.)
5 Institute of Nonferrous Metallurgy, Montanuniversität Leoben, 8700 Leoben, Austria

Back to TopTop