Photocoupling of fibronectin to titanium surfaces influences keratinocyte adhesion, pellicle formation and thrombogenicity

Scheideler, Lutz; Rupp, Frank; Wendel, Hans P.; Sathe, Shila; Geis-Gerstorfer, Jürgen

doi:10.1016/j.dental.2006.03.005

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Volume 23, Issue 4 , Pages 469-478, April 2007

Photocoupling of fibronectin to titanium surfaces influences keratinocyte adhesion, pellicle formation and thrombogenicity

Lutz Scheideler
- Department of Prosthodontics, Section Medical Materials and Technology, Center for Dental, Oral and Maxillofacial Medicine, University of Tübingen, Germany
- Corresponding author. Tel.: +49 7071 2985781; fax: +49 7071 293982.
Frank Rupp
- Department of Prosthodontics, Section Medical Materials and Technology, Center for Dental, Oral and Maxillofacial Medicine, University of Tübingen, Germany
Hans P. Wendel
- Department of Thoracic, Cardiac and Vascular Surgery, University of Tübingen, Germany
Shila Sathe
- Department of Prosthodontics, Section Medical Materials and Technology, Center for Dental, Oral and Maxillofacial Medicine, University of Tübingen, Germany
Jürgen Geis-Gerstorfer
- Department of Prosthodontics, Section Medical Materials and Technology, Center for Dental, Oral and Maxillofacial Medicine, University of Tübingen, Germany

Received 3 June 2005; received in revised form 13 February 2006; accepted 9 March 2006.

Abstract

Objectives

Coating of implant surfaces with biomolecules can influence basic host responses and enhance subsequent tissue integration. The biological factors have to be immobilized on the implant material. Human fibronectin (Fn) was used as a model protein and covalently coupled to titanium (Ti) surfaces via silanization and an anthraquinone linker. The impact on several aspects of initial host/biomaterial interactions (keratinocyte adhesion, platelet interactions and pellicle formation) was studied.

Methods

Coupling efficiency was characterized by immunological techniques. The effects of coupled Fn on initial host/biomaterial interactions were assessed. Cell adhesion and spreading were investigated by fluorescent staining, pellicle formation by an acoustic sensor system (quartz crystal microbalance with dissipation, QCM-D), and platelet adhesion as one parameter mediating the inflammatory response by scanning electron microscopy (SEM) and immunological assays.

Results

Coupling efficiency was related to irradiation time used for photochemical coupling of the UV-activated anthraquinone to the silanized Ti surface. With an optimized protocol, the amount of Fn coupled to the surface could be almost doubled compared to standard dip-coating methods. On the anthraquinone-coupled Fn coatings, cell adhesion and spreading of human keratinocytes was significantly enhanced. Online detection of pellicle formation revealed strong reversibility of saliva protein adhesion on Fn coated surfaces compared to the pure Ti surface. Furthermore, the Fn coated Ti showed a low thrombogenicity.

Significance

This study suggests that anthraquinone-coupled biological coatings may be useful for biofunctionalization of Ti dental implants by enhancement of soft tissue re-integration (restoration of the epithelial seal) combined with diminished pellicle formation.

Keywords: Dental implants, Titanium, Biofunctionalization, Fibronectin, Anthraquinone photocoupling, Epithelial seal, Keratinocyte adhesion, Platelet activation, Pellicle formation, QCM-D