The effect of titanium surface roughening on protein absorption, cell attachment, and cell spreading

Purpose: The purpose of this study was to compare properties of roughened and polished titanium with respect to their ability to attach to cells and bind to protein as well as their cell spreading behavior. Materials and Methods: Three different titanium surface treatments were compared for their ability to support cell attachment and spreading: sandblasted and acid-etched, resorbable blast media, and machine-polished titanium. The surface of the materials was characterized for surface roughness, surface energy, and surface chemistry. Osteoblast-like MG-63 cells were tested for in vitro attachment and spreading in the presence of serum proteins. Cell attachment was assessed by direct counting, dye binding, and microculture titanium assays. Cell spreading was determined by measuring area/cell in phalloidin-AlexaFluor 488 stained cells. Absorption of bovine serum albumin was determined by assay. Results: Scanning electron micrography and x-ray diffractometry confirmed increased surface roughness of the roughened materials. All 3 materials had similar albumin binding kinetics. Three different methods confirmed that roughened surfaces enhance early cell attachment to titanium in the presence of serum. Cells spread better on smoother machined surfaces than on the roughened surfaces. Conclusion: Roughened titanium surfaces exhibited better early cell attachment than smooth surfaces in the presence of serum. The cells attached to roughened titanium were less spread than those attached to machined titanium. Although albumin binding was not different for roughened surfaces, it is possible that roughened surfaces preferentially bound to serum adhesive proteins to promote early cell attachment.