Effect of pore size on tissue ingrowth and osteoconductivity in biodegradable Mg alloy scaffolds

authored by: Julia Augustin, Franziska Feichtner, Anja Christina Waselau, Stefan Julmi, Christian Klose, Peter Wriggers, Hans Jürgen Maier, Andrea Meyer-Lindenberg
Abstract: Magnesium has mechanical properties similar to those of bone and is being considered as a potential bone substitute. In the present study, two different pore sized scaffolds of the Mg alloy LAE442, coated with magnesium fluoride, were compared. The scaffolds had interconnecting pores of either 400 (p400) or 500 µm (p500). ß-TCP served as control. Ten scaffolds per time group (6, 12, 24, 36 weeks) were implanted in the trochanter major of rabbits. Histological analyses, µCT scans, and SEM/EDX were performed. The scaffolds showed slow volume decreases (week 36 p400: 9.9%; p500: 7.5%), which were accompanied by uncritical gas releases. In contrast, ß-TCP showed accelerated resorption (78.5%) and significantly more new bone inside (18.19 ± 1.47 mm3). Bone fragments grew into p400 (0.17 ± 0.19 mm3) and p500 (0.36 ± 0.26 mm3), reaching the centrally located pores within p500 more frequently. In particular, p400 displayed a more uneven and progressively larger surface area (week 36 p400: 253.22 ± 19.44; p500: 219.19 ± 4.76 mm2). A better osseointegration of p500 was indicated by significantly more trabecular contacts and a 200 µm wide bone matrix being in the process of mineralization and in permanent contact with the scaffold. The number of macrophages and foreign body giant cells were at an acceptable level concerning resorbable biomaterials. In terms of ingrown bone and integrative properties, LAE442 scaffolds could not achieve the results of ß-TCP. In this long-term study, p500 appears to be a biocompatible and more osteoconductive pore size for the Mg alloy LAE442.
Organisation(s): Institute of Materials Science
Institute of Continuum Mechanics
External Organisation(s): Ludwig-Maximilians-Universität München (LMU)
Type: Article
Journal: Journal of applied biomaterials & functional materials
Volume: 20
ISSN: 2280-8000
Publication date: 21.02.2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Biophysics, Bioengineering, Biomaterials, Biomedical Engineering
Electronic version(s): https://doi.org/10.1177/22808000221078168 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{cc26786fbfb24190ae158922ebea29cc,
title = "Effect of pore size on tissue ingrowth and osteoconductivity in biodegradable Mg alloy scaffolds",
abstract = "Magnesium has mechanical properties similar to those of bone and is being considered as a potential bone substitute. In the present study, two different pore sized scaffolds of the Mg alloy LAE442, coated with magnesium fluoride, were compared. The scaffolds had interconnecting pores of either 400 (p400) or 500 µm (p500). {\ss}-TCP served as control. Ten scaffolds per time group (6, 12, 24, 36 weeks) were implanted in the trochanter major of rabbits. Histological analyses, µCT scans, and SEM/EDX were performed. The scaffolds showed slow volume decreases (week 36 p400: 9.9%; p500: 7.5%), which were accompanied by uncritical gas releases. In contrast, {\ss}-TCP showed accelerated resorption (78.5%) and significantly more new bone inside (18.19 ± 1.47 mm3). Bone fragments grew into p400 (0.17 ± 0.19 mm3) and p500 (0.36 ± 0.26 mm3), reaching the centrally located pores within p500 more frequently. In particular, p400 displayed a more uneven and progressively larger surface area (week 36 p400: 253.22 ± 19.44; p500: 219.19 ± 4.76 mm2). A better osseointegration of p500 was indicated by significantly more trabecular contacts and a 200 µm wide bone matrix being in the process of mineralization and in permanent contact with the scaffold. The number of macrophages and foreign body giant cells were at an acceptable level concerning resorbable biomaterials. In terms of ingrown bone and integrative properties, LAE442 scaffolds could not achieve the results of {\ss}-TCP. In this long-term study, p500 appears to be a biocompatible and more osteoconductive pore size for the Mg alloy LAE442.",
keywords = "bone ingrowth, LAE442, osseointegration, osteoconductivity, Pore size",
author = "Julia Augustin and Franziska Feichtner and Waselau, {Anja Christina} and Stefan Julmi and Christian Klose and Peter Wriggers and Maier, {Hans J{\"u}rgen} and Andrea Meyer-Lindenberg",
note = "Funding Information: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the German Research Foundation within the project “Interfacial effects and integration behavior of magnesium-based sponges as bioresorbable bone substitute material” [grant number: 271761343].",
year = "2022",
month = feb,
day = "21",
doi = "10.1177/22808000221078168",
language = "English",
volume = "20",
journal = "Journal of applied biomaterials & functional materials",
issn = "2280-8000",
publisher = "SAGE Publications Inc.",
}