Finite Element Modeling of the Flexural Mechanical Response of Polymer-Coated Bioactive Glass Scaffolds Composed of Thermally-Bonded Unidirectional Fibers

摘要

Bioactive glasses have attractive characteristics as a scaffold material for healing bone defects but their brittle mechanical response, particularly in bending, is a concern. Recent studies have shown that coating the external surface of strong porous bioactive glass (13-93) scaffolds with an adherent biodegradable polymer layer can significantly improve their load-bearing capacity andwork of fracture, resulting in a non-brittle mechanical response. In the present study, finite element modeling (FEM) was used to analyze the mechanical response in four-point bending of composites composed of a porous glass scaffold and an adherent polymer surface layer. The glass scaffold with a cylindrical geometry (diameter = 4.2 mm; porosity = 20%) was composed of randomly arranged unidirectional fibers (diameter 200-700 μm) thatwere bonded at their contact points. The thickness of the polymer layer was 500 μm. By analyzing the stresses in the individual glass fibers, the simulations can account for the main trends in the observed mechanical response of practical composites with a similar architecture composed of a bioactive glass (13-93) scaffold and an adherent polylactic acid surface layer. These FEM simulations could play a useful role in designing bioactive glass composites with improved mechanical properties.