A co-dispersion nanosystem of graphene oxide @silicon-doped hydroxyapatite to improve scaffold properties

Highlights: • A co-dispersion nanosystem of GO@Si-HA was constructed via in-situ growth technique. • The dispersibility of GO and Si-HA nanoparticles in PLLA scaffold can be simultaneously improved, achieving a co-dispersion reinforcing effect. • The PLLA/GO@Si-HA scafffold was prepared via selective laser sintering. • Compressive strength and modulus of the scaffold have increased by 85% and 120% compared with PLLA scaffolds. • The scaffold promoted cell adhesion, proliferation and differentiation. Poly l-lactic acid (PLLA) was limited in the further orthopaedic application due to its insufficient mechanical property and poor bioactivity. Graphene oxide (GO) is an effective reinforcement, whereas silicon-doped hydroxyapatite (Si-HA) possesses excellent bioactivity, but either GO or Si-HA tends to aggregate in PLLA matrix. In this study, a GO@Si-HA nanosystem was achieved by in-situ growth of Si-HA on GO, and then incorporated into PLLA scaffold fabricated by laser sintering technology. On one hand, Si-HA on the surface of GO effectively prevented the aggregation of GO by acting as a barrier between GO nanosheets. On the other hand, GO hindered the aggregation of Si-HA by means of anchoring Si-HA. Results displayed that the compressive strength and modulus of the PLLA/GO@Si-HA composite scaffold were enhanced by 85% and 120%, respectively. Meanwhile, the scaffold exhibited significantly improved bioactivity, and consequently promoted cell adhesion, proliferation and differentiation. The developed PLLA/GO@Si-HA composite scaffold with excellent mechanical properties and superior bioactivity could serve as a promising substitute for bone repairing.