Mechanical Behaviour Of Bioactive Glass/Polymer Composte Scaffolds For Repairig Load Bearing Bones

Developing a glass scaffold suitable for repairing defects in load-bearing bones, has been a challenging task due to the brittle and catastrophic failure characteristics of glass, especially when subjected to flexural or tensile stresses. In the present work, the flexural strength of cylindrical scaffolds composed of thermally bonded, unidirectional 13-93 silicate glass fibres, was compared with the flexural strength of a cylindrical composite scaffold. The composite scaffold consisted of a core of the same thermally bonded, unidirectional glass fibres, but the core was encased with a nominal 500 micron thick layer of a biodegradable polymer polylactic acid (PLA). The flexural strength of the PLA composite scaffold (~120 MPa) was more than twice that of the all-glass "bare" scaffolds (no PLA) and was within the range for the flexural strength of cortical bone. Unlike the brittle, catastrophic failure observed for bare scaffolds, the composite scaffold behaved as a ductile material under flexural loads and remained load bearing even after significant physical/mechanical damage had occurred during flexural loading. The higher flexural strength of composite scaffolds along with their ductility under flexural loads and their cylindrical geometry are important advantages compared to all-glass "bare" scaffolds.