Injectable Photocrosslinkable Nanocomposite Based on Poly(glycerol Sebacate) Fumarate and Hydroxyapatite: Development, Biocompatibility and Bone Regeneration in a Rat Calvarial Bone Defect Model

Aim: An injectable, photocrosslinkable nanocomposite was prepared using a fumarate derivative of poly(glycerol sebacate) and nanohydroxyapatite.

Materials & Methods: Polymers with varying physical and mechanical properties were synthesized. Furthermore, nanocomposites were developed using a homogenization process by combining nanohydroxyapatite within poly(glycerol sebacate) matrix via photocrosslinking and evaluated both in vitro and in vivo.

Results & Discussion: The nanocomposites were injectable, highly bioactive and biocompatible. Addition of nanohydroxyapatite led to enhanced mechanical properties with an ultimate strength of 8 MPa. The optimized nanocomposite showed good in vitro cell attachment, proliferation and differentiation of rat bone marrow-derived mesenchymal stem cells. The in vivo evaluation in a rat calvarial bone defect model showed significantly high alkaline phosphatase activity and bone regeneration.

Conclusion: This injectable, biocompatible and bioactive in situ hardening composite graft was found to be suitable for load-bearing bone regeneration applications using minimally invasive surgery.