When adsorbed to implant surfaces, osteogenic proteins such as fibronectin induce bone cell adhesion, growth, maturation and the formation of a mineralized matrix. Therefore, such proteins may be useful in accelerating osseointegration of dental and orthopedic implants and prolong their longevity. Studies of nteractions between fibronectin and titanium materials suggest that the negative charge of the surface oxide modulates the structure of the protein to increase the functional presentation of its cell binding domain to osteoblast integrin receptors. Furthermore, the biological potency of fibronectin as a bone cell adhesive protein may be increased by the use of surface treatments such as thermal oxidation and radiofrequency glow discharge which increase the concentration and negative charge of surface oxides. It is our hypothesis that this latter oxide property is uniquely capable of inducing adsorbed fibronectin to bind with higher affinity to functional bone cell receptors and thereby attach to more cells, stimulate cell spreading and accelerate and strengthen implant integration. To test this hypothesis we will address the following aims:
Aim I. To demonstrate that negatively charged metallic surface oxides increase the number of bone cells that attach to preadsorbed fibronectin and exhibit a spreading response associated with cell adhesion;
Aim II. To demonstrate that negatively charged metallic surface oxides induce adsorbed fibronectin to bind with higher affinity to functional bone receptors and promote osteogenesis;
Aim III. To demonstrate that negatively charged metallic surface oxides enhance the ability of adsorbed fibronectin to accelerate and strengthen implant bonding to bone in an animal model. This proposal intends to validate our strategy of forming a more highly charged implant surface oxide followed by fibronectin coating to achieve a more robust fixation in less time. Therefore, the implant's longevity may be enhanced by using this simple and relatively inexpensive preparative procedure.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE017695-04
Application #
7851437
Study Section
Oral, Dental and Craniofacial Sciences Study Section (ODCS)
Program Officer
Drummond, James
Project Start
2007-08-01
Project End
2012-06-30
Budget Start
2010-07-01
Budget End
2011-06-30
Support Year
4
Fiscal Year
2010
Total Cost
$425,310
Indirect Cost
Name
Hospital for Special Surgery
Department
Type
DUNS #
622146454
City
New York
State
NY
Country
United States
Zip Code
10021
Rapuano, Bruce E; MacDonald, Daniel E (2013) Structure-activity relationship of human bone sialoprotein peptides. Eur J Oral Sci 121:600-9
Rapuano, Bruce E; Singh, Herman; Boskey, Adele L et al. (2013) Heat and radiofrequency plasma glow discharge pretreatment of a titanium alloy: evidence [corrected] for enhanced osteoinductive properties. J Cell Biochem 114:1917-27
MacDonald, Daniel E; Rapuano, Bruce E; Vyas, Parth et al. (2013) Heat and radiofrequency plasma glow discharge pretreatment of a titanium alloy promote bone formation and osseointegration. J Cell Biochem 114:2363-74
Rapuano, Bruce E; Lee, Jani J E; MacDonald, Daniel E (2012) Titanium alloy surface oxide modulates the conformation of adsorbed fibronectin to enhance its binding to ýý(5) ýý(1) integrins in osteoblasts. Eur J Oral Sci 120:185-94
Rapuano, Bruce E; Hackshaw, Kyle; Macdonald, Daniel E (2012) Heat or radiofrequency plasma glow discharge treatment of a titanium alloy stimulates osteoblast gene expression in the MC3T3 osteoprogenitor cell line. J Periodontal Implant Sci 42:95-104
Rapuano, Bruce E; Hackshaw, Kyle M; Schniepp, Hannes C et al. (2012) Effects of coating a titanium alloy with fibronectin on the expression of osteoblast gene markers in the MC3T3 osteoprogenitor cell line. Int J Oral Maxillofac Implants 27:1081-90
MacDonald, Daniel E; Rapuano, Bruce E; Schniepp, Hannes C (2011) Surface oxide net charge of a titanium alloy: comparison between effects of treatment with heat or radiofrequency plasma glow discharge. Colloids Surf B Biointerfaces 82:173-81
Rapuano, Bruce E; MacDonald, Daniel E (2011) Surface oxide net charge of a titanium alloy: modulation of fibronectin-activated attachment and spreading of osteogenic cells. Colloids Surf B Biointerfaces 82:95-103