Proliferation of osteoblasts and fibroblasts on model surfaces of varying roughness and surface chemistry

Abstract

Phys. and chem. properties of the surfaces of implants are of considerable interest for dental and orthopedic applications. We used self-assembled monolayers (SAMs) terminated by various functional chem. groups to study the effect of surface chem. on cell behavior. Cell morphol. and proliferation on silicon wafers of various roughnesses and topogs. created by chem. etching in caustic soln. and by corundum sandblasting were analyzed as well. Water contact angle data indicated that oxidized wafer surfaces displayed high hydrophilicity, modification with poly(ethylene glycol) (PEG) created a hydrophilic surface, and an amino group (NH2) led to a moderately wettable surface. A hydrophobic surface was formed by hydrocarbon chains terminated by CH3, but this hydrophobicity was even further increased by a fluorocarbon (CF3) group. Cell proliferation on these surfaces was different depending primarily on the chem. of the terminating groups rather than on wettability. Cell proliferation on CH3 was as high as on NH2 and hydrophilic oxidized surfaces, but significantly lower on CF3. Precoating of silicon wafers with cell culture serum had no significant influence on cell proliferation. SEM indicated a very weak initial cell-surface contact on CF3. The cell no. of osteoblasts was significantly lower on sandblasted surfaces compared with other rough surfaces but no differences were detected with 3T3 mouse fibroblasts. The different surface roughnesses and topogs. were recognized by MG-63 osteoblasts. The cells spread well on smooth surfaces but appeared smaller on a rough and unique pyramid-shaped surface and on a rough sandblasted surface.