The Role of Fetuin-A on the Attachment and Proliferation of Osteoblast-like Cells on Model Gold Surfaces

Fetuin-A is a plasma protein of interest for bone-interfacing applications because of its role in mineralization processes through calcium/phosphate ion-binding capabilities. However, the role of fetuin A in the initial stages of cellular interaction with biomaterials and the mechanisms involved are not fully clear. This work investigated the response of osteoblast-like Saos-2 cells to model gold substrates presenting preadsorbed fetuin-A as a surface modification to determine the role of the protein in cell attachment and proliferation. Correlative quartz crystal microbalance with dissipation (QCM-D), surface plasmon resonance, and radiolabeling confirmed that fetuin-A adsorbed on model surfaces in similar quantities compared to serum albumin but formed a less packed layer with increased water entrapment. Cells attached to gold surfaces presenting preadsorbed fetuin-A displayed morphological characteristics similar to those with preadsorbed albumin with lower average surface area and maximum axis compared to the fibronectin control. Over 3 days, fetuin-A exhibited lower cellular proliferation compared to the fibronectin control, likely correlated to the decrease in cellular metabolism observed at the same time point, and persisted over 7 days. These results provide insight into the role of adsorbed fetuin-A for bone-interfacing implant applications, suggesting that the preadsorption of the protein alone is not sufficient to promote early stages of osseointegration.