Evaluation of calcium phosphate–coated polycaprolactone/graphene oxide scaffold with macro- and microporous structure for bone tissue engineering

Objectives: This study aimed to fabricate porous PCL/GO scaffolds by adding graphene oxide (GO) which is a hydrophilic material to improve cell affinity of PCL. Calcium phosphate (CaP) coating was performed to enhance the bioactivity of the composite scaffold. The phase separation methods and the salt leaching process were used to impart high porosity and pores of various sizes in the scaffolds. Methods: The scaffolds were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), water contact angle test, swelling test, and mechanical tests. For in vitro evaluation, cell morphology and viability test, alkaline phosphatase (ALP) activity, and double-stranded DNA (dsDNA) quantification were performed using mouse bone marrow stem cells (mBMSCs). Results: All scaffolds had interconnected pore networks for transporting nutrients, oxygen, and waste products. GO addition and CaP coating improved hydrophilicity, swelling behavior, mechanical properties, and cell proliferation properties of the scaffolds by creating a biomimetic 3D microenvironment. The PCL/GO/CaP scaffold laden with mBMSCs had no clear cytotoxicity and further promoted osteogenic differentiation compared to the groups without GO or CaP. Conclusions: Our results suggest that the porous PCL/GO/CaP scaffold showed enhanced hydrophilicity and swelling behavior and exerted beneficial effects on cell proliferation and differentiation. This composite scaffold shows potential for clinical application in bone tissue engineering.