Effect of silane coupling agent treated bovine bone based carbonated hydroxyapatite on in vitro degradation behavior and bioactivity of PLA composites

In this study, effect of treating bovine bone based carbonated hydroxyapatite (CHA) with silane coupling agent on in vitro degradation and bioactivity of PLA composites were investigated. PLA composite specimens containing CHA and silane-treated CHA were immersed in phosphate-buffered solution at 37 °C for the periods of time up to 8 weeks. The changes in specimen weights and morphologies, pH of PBS solution and PLA molecular weight were examined. The results showed that the strong interfacial bonding between silane-treated CHA and PLA matrix significantly delayed in vitro degradation of the PLA composites. However, the bioactivity of the PLA/silane treated CHA composites, determined by the formation of poorly crystalline calcium phosphate compounds on the specimen surface after immersion in simulated body fluid (SBF), seemed to be lower than that of the PLA/CHA composite.

► Natural carbonated hydroxyapatite (CHA) was obtained from bovine bone waste.
► Strong interfacial bonding occurred between silane treated CHA and PLA matrix.
► This led to good mechanical and thermal properties of the PLA composites.
► PLA/silane treated CHA composites had no toxicity to human cells.
► Silane treated CHA delayed in vitro degradation and reduced bioactivity of PLA composites.