The emergence of polylactide composites reinforced with bioresorbable silicate glass\nfibers has allowed for the long-term success of biodegradable polymers in load-bearing orthopedic\napplications. However, few studies have reported on the degradation behavior and bioactivity of\nsuch biocomposites. The aim of this work was to investigate the degradation behavior and in vitro\nbioactivity of a novel biocomposite pin composed of bioresorbable continuous glass fibers and\npoly-L-D-lactide in simulated body fluid for 78 weeks. As the materials degraded, periodic spiral\ndelamination formed microtubes and funnel-shaped structures in the biocomposite pins. It was\nspeculated that the direction of degradation, from both ends towards the middle of the fibers\nand from the surface through to the bulk of the polymer matrix, could facilitate bone healing.\nFollowing immersion in simulated body fluid, a bone-like apatite layer formed on the biocomposite\npins which had a similar composition and structure to natural bone. The sheet- and needle-like\napatite nanostructure was doped with sodium, magnesium, and carbonate ions, which acted to lower\nthe Ca/P atomic ratio to less than the stoichiometric apatite and presented a calcium-deficient apatite\nwith low crystallinity. These findings demonstrated the bioactivity of the new biocomposite pins\nin vitro and their excellent potential for load-bearing applications.
Loading....