3D nanoscale analysis of bone healing around degrading Mg implants evaluated by X-ray scattering tensor tomography
Artikel i vetenskaplig tidskrift, 2021

The nanostructural adaptation of bone is crucial for its biocompatibility with orthopedic implants. The bone nanostructure also determines its mechanical properties and performance. However, the bone's temporal and spatial nanoadaptation around degrading implants remains largely unknown. Here, we present insights into this important bone adaptation by applying scanning electron microscopy, elemental analysis, and small-angle X-ray scattering tensor tomography (SASTT). We extend the novel SASTT reconstruction method and provide a 3D scattering reciprocal space map per voxel of the sample's volume. From this reconstruction, parameters such as the thickness of the bone mineral particles are quantified, which provide additional information on nanostructural adaptation of bone during healing. We selected a rat femoral bone and a degrading ZX10 magnesium implant as model system, and investigated it over the course of 18 months, using a sham as control. We observe that the bone's nanostructural adaptation starts with an initially fast interfacial bone growth close to the implant, which spreads by a re-orientation of the nanostructure in the bone volume around the implant, and is consolidated in the later degradation stages. These observations reveal the complex bulk bone-implant interactions and enable future research on the related biomechanical bone responses. Statement of significance: Traumatic bone injuries are among the most frequent causes of surgical treatment, and often require the placement of an implant. The ideal implant supports and induces bone formation, while being mechanically and chemically adapted to the bone structure, ensuring a gradual load transfer. While magnesium implants fulfill these requirements, the nanostructural changes during bone healing and implant degradation remain not completely elucidated. Here, we unveil these processes in rat femoral bones with ZX10 magnesium implants and show different stages of bone healing in such a model system.

Tomography

X-ray scattering

Biomineralization

Degradable magnesium implants

Implant degradation

Författare

Marianne Liebi

Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa)

Chalmers, Fysik, Materialfysik

Paul Scherrer Institut

Viviane Lutz-Bueno

Paul Scherrer Institut

Manuel Guizar-Sicairos

Paul Scherrer Institut

Bernd M. Schönbauer

Universität für Bodenkultur

Johannes Eichler

Medizinische Universität Graz

Elisabeth Martinelli

Medizinische Universität Graz

Jörg F. Löffler

Eidgenössische Technische Hochschule Zürich (ETH)

Annelie Weinberg

Medizinische Universität Graz

Helga Lichtenegger

Universität für Bodenkultur

Tilman A. Grünewald

European Synchrotron Radiation Facility (ESRF)

Acta Biomaterialia

1742-7061 (ISSN)

Vol. In Press

Ämneskategorier

Biomaterial

Biomaterialvetenskap

Medicinska material och protesteknik

DOI

10.1016/j.actbio.2021.07.060

Mer information

Senast uppdaterat

2021-08-26