ABSTRACT
This study investigated the influence of surface wettability on competitive protein adsorption and the initial attachment of osteoblasts. A thin-film coating of hexamethyldisiloxane (HMDSO) and subsequent O(2)-plasma treatment was carried out on substrates with a mirror surface in order to create a wide range of wettabilities. The adsorption behavior of fibronectin (Fn) and albumin (Alb) in both individual and competitive mode, and the initial attachment of mouse osteoblastic cells (MC3T3-E1) over a wide range of wettabilities were investigated. The contact angle of HMDSO coatings without O(2)-plasma treatment against double-distilled water was more than 100 degrees, whereas it dramatically decreased after the O(2)-plasma treatment to almost 0 degrees, resulting in super-hydrophilicity. Individually, Fn adsorption showed a biphasic inclination, whereas Alb showed greater adsorption to hydrophobic surfaces. In the competitive mode, in a solution containing both Fn and Alb, Fn showed greater adsorption on hydrophilic surfaces, whereas Alb predominantly adsorbed on hydrophobic surfaces. The initial attachment of osteoblastic cells increased with an increase in surface wettability, in particular, on a super-hydrophilic surface, which correlated well with Fn adsorption in the competitive mode. These results suggest that Fn adsorption may be responsible for increasing cell adhesion on hydrophilic surfaces in a body fluid or culture media under physiological conditions.
Subject(s)
Albumins/chemistry , Coated Materials, Biocompatible/chemistry , Fibronectins/chemistry , Osteoblasts/physiology , Siloxanes/chemistry , Adsorption , Animals , Cell Adhesion , Cells, Cultured , Fluorescein-5-isothiocyanate/metabolism , Fluorescent Antibody Technique, Indirect , Fluorescent Dyes/metabolism , Hydrophobic and Hydrophilic Interactions , Mice , Osteoblasts/cytology , Osteoblasts/ultrastructure , Rhodamines/metabolism , Surface Properties , Time Factors , WettabilityABSTRACT
Oral manifestations of Down syndrome include high susceptibility to gingival inflammation with early onset and rapidly progressive periodontitis. The influence of reactive oxygen species (ROS) on periodontitis of Down syndrome is unclear. The aim of this study was to characterize ROS formation in Down syndrome-gingival fibroblasts (DS-GF) using electron spin resonance (ESR) spin trapping with 5,5-dimetyl-1-pyrolline-N-oxide (DMPO), and to determine whether ROS generation plays a role in the pathogenesis of periodontitis in Down syndrome patients. We observed formation of the DMPO-OH spin adduct, indicating HO* generation from cultured DS-GF and non-DS-GF. The increased HO* generation in cultured DS-GF was strongly decreased in the presence of the H2O2 scavenger, catalase, or the iron chelator, desferal. This may due to the enzymatic ability of over-expressed CuZn-superoxide dismutase in Down syndrome to catalyze the formation of H2O2 from O2*-, thereby increasing the availability of substrate H2O2 for the iron-dependent generation of HO* via the Fenton reaction, suggesting that HO* generated from DS-GF may be involved in progressive periodontitis of Down syndrome.
