Biomimetic Calcium Phosphate Coated Macro-Microporous Poly(ε-caprolactone)/Silk Fibroin (PCL/SF) Scaffold for Bone Tissue Engineering

Because of an aging population and social development, tissue engineering techniques have been widely studied and used for patient treatment. To improve bone regeneration and overcome disadvantages, suitable biomaterials have to be chosen. Polycaprolactone (PCL) is extensively used in bone tissue engineering, known for its excellent mechanical properties, high crystallinity, toughness, and bio-compatibility. In addition, porous PCL can induce bone ingrowth into its macropores and can be used for the repair and regeneration of the bone. However, PCL has limited cell affinity primarily owing to the lack of cell recognition sites due to its hydrophobic surface. To compensate drawbacks of PCL scaffolds, silk fibroin (SF), non-solvent and thermal-induced phase separation (N-TIPS), and salt-leaching were utilized in this study. Additionally, to overcome the disadvantage that the polymeric scaffold may be insignificant for osteoinduction, PCL/SF scaffolds were coated with calcium phosphate (CaP) (c-PCL/SF). Physicochemical properties, biological activity, and mechanical characters were analyzed to confirm applicability in bone tissue engineering. Also, in vitro study was performed with viability test, morphology study, proliferation test, and gene expression evaluation. The mechanical property of the c-PCL/SF scaffold was improved when compared to the coated PCL scaffold (c-PCL), and the bioactivity of the c-PCL/SF showed a high amount of apatite formation. Also, bone marrow stem cells (BMSC) cultured in c-PCL/SF scaffolds showed enhanced viability and bone-specific gene expression than the BMSC cultured in c-PCL. Overall, the c-PCL/SF scaffolds were compatible material to apply in bone tissue engineering biomaterial.