Tough and Strong Porous Bioactive Glass-PLA Composites for Structural Bone Repair

Abstract

Bioactive glass scaffolds have been used to heal small contained bone defects, but their application to repairing structural bone is limited by concerns about their mechanical reliability. In the present study, the addition of an adherent polymer layer to the external surface of strong porous bioactive glass (13-93) scaffolds was investigated to improve their toughness. Finite element modeling (FEM) of the flexural mechanical response of beams composed of a porous glass and an adherent polymer layer predicted a reduction in the tensile stress in the glass with increasing thickness and elastic modulus of the polymer layer. Mechanical testing of composites with structures similar to the models, formed from 13-93 glass and polylactic acid (PLA), showed trends predicted by the FEM simulations, but the observed effects were considerably more dramatic. A PLA layer of thickness ~400 µm, equal to ~12.5% of the scaffold thickness, increased the load-bearing capacity of the scaffold in four-point bending by ~50%. The work of fracture increased by more than 10000%, resulting in a non-brittle mechanical response. These bioactive glass-PLA composites, combining bioactivity, high strength, high work of fracture and an internal architecture shown to be conducive to bone infiltration, could provide optimal implants for healing structural bone defects.

Department(s)

Materials Science and Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Keywords and Phrases

Bone; Bone Cement; Brittle Fracture; Finite Element Method; Fracture; Mechanical Testing; Polymers; Repair; Scaffolds; External Surfaces; Four Point Bending; Internal Architecture; Load-Bearing Capacity; Mechanical Reliability; Mechanical Response; Porous Bioactive Glass; Scaffold Thickness; Bioactive Glass

International Standard Serial Number (ISSN)

0022-2461

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2017 Springer US, All rights reserved.

Publication Date

01 Aug 2017

Link to Full Text

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