In vitro behaviour of osteoblasts cultured on orthopaedic biomaterials with different surface roughness, uncoated and fluorohydroxyapatite-coated, relative to the in vivo osteointegration rate

The effects of two surfaces with different roughness (Low Roughness, LR: Ra: 5.6-5.9 μm; High Roughness, HR: Ra: 21.5-22.5 μm), uncoated and fluorohydroxyapatite(FHA)-coated, were investigated in MG-63 osteoblasts. At 72 hours, cells proliferated on biomaterials more slowly than in the control group (p < 0.0001), the proliferation rate was higher on FHA-coated LR than uncoated HR (p = 0.037). Collagen-I production was positively affected by the LR surface (p = 0.001) as compared to controls, while it was significantly lower (p = 0.0001) in the HR surfaces. Compared to controls, LR and HR surfaces led to enhanced production of TGF-β1, further improved by FHA (FHA-coated LR: p = 0.007; FHA-coated HR p < 0.0001 respectively). ALP, OC, IL-6 and TNF-α levels were not significantly different from the controls. Results suggest that collagen-I production could be useful in predicting the in vivo osteointegration rate of biocompatible biomaterials observed in previous studies.