Microstructures and properties of polycaprolactone/tricalcium phosphate scaffolds containing polyethylene glycol fabricated by 3D printing

Polymer scaffolds have attracted extensive attention in tissue engineering, especially polycaprolactone (PCL) scaffolds. However, the lack of biological activity and inherent hydrophobicity of PCL limits its application. PCL composites scaffolds have been produced to improve the material properties. Here, the scaffold with polyethylene glycol (PEG)-coated beta-tricalcium phosphate (TCP) surface structure was made from PCL/TCP/PEG composite materials through 3D printing. SEM, OM, and Micro-CT were used to determine the scaffold morphology. The scaffolds had uniform filament diameters (approximately 400 mu m) and interconnected pore structures. Compared with the PCL scaffolds, the PCL/TCP/PEG scaffolds exhibited good wettability (contact angle decreased from 85 degrees to 0 degrees, showing complete wettability). The compressive mechanical test showed that the yield strength of the PCL/TCP/PEG scaffold was 1.35 MPa. In vitro mineralization experiments showed that hydroxyapatite formed on the PCL/TCP/PEG scaffolds after 14 days of immersion. After 5 days of cell co-culture, cells on the PCL/TCP/PEG scaffolds exhibited the highest cell viability. The osteogenic differentiation of cells on the PCL/TCP/PEG scaffolds was significantly increased. Meanwhile, after 14 days of co-culture, the ALP content of PCL/TCP/PEG scaffolds was 2.5 times that of PCL scaffolds. This study shows that the PEG-coated TCP structure of PCL/TCP/PEG scaffolds improved the hydrophilicity, mineralization properties, cell proliferation, and osteogenic differentiation, showing potential applications in bone defect repair.

Automated summary

PCL/TCP/PEG composite scaffolds with PEG-coated TCP structure were prepared to improve the biological activity and hydrophobicity issues of PCL materials. The scaffolds exhibited good wettability, morphology, and mechanical properties, and promoted cell proliferation and osteogenic differentiation.