Comparison Study of Osteoblast Cells Adhesion on the 3D-printed Scaffolds

Objectives: The polymeric scaffolds were fabricated from polycaprolactone through 3D printing. The surface of the scaffolds was coated with the mixture of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) to increase the mechanical properties, cell proliferation, and adhesion of the scaffolds.
Methods: The printing parameters were optimized and PCL scaffolds were 3D-printed. A facile and high-performance approach was developed to coat the surface of PCL scaffolds with a slurry mixture of β-TCP and HA using hydrostatic pressure. A 2-ml cylindrical reservoir was used for coating β-TCP and HA slurry with the concentration of 60 % wt. and kept under pressure at 65 C for an hour. The biocompatibility, cell proliferation, and differentiation of scaffolds were investigated by culturing the osteoblast cells on the coated scaffolds.
Results: The results revealed that the scaffolds were completely coated with the mixture of β-TCP and HA slurry. The surface roughness measurements showed that the coated scaffolds possess more roughness for cell adhesion compared to the uncoated scaffolds. The mechanical properties of uncoated and coated scaffolds revealed that the modulus of the coated scaffolds significantly increased. The cell culture results showed that adhesion and proliferation of osteoblast cells significantly improved while using a coated scaffold in the presence of HA. The alkaline phosphate (ALP) assay displayed a gradual increase in ALP activity at each time point (days 7, 14, 21). These results also signify a higher osteogenic differentiation capacity for the coated scaffolds with HA. A Presto blue cell proliferation assay confirmed the superiority of coated scaffolds compared to controls at each time point tested (days 7, 14, 21), as well as a gradual increase across time points.
Conclusions: The obtained experimental results ascertain that coating the surface of scaffolds with a mixture of β-TCP and HA slurry shows high potential application for bone tissue engineering.