Assessment of novel chemical strategies for covalent attachment of adhesive peptides to rough titanium surfaces: XPS analysis and biological evaluation

Abstract

Bioactive molecules have been proposed to promote beneficial interactions at bone-implant interfaces for enhancing integration. The main objective of this study was to develop novel methods to functionalize oxidized titanium surfaces by the covalent immobilization of bioactive peptides, through selective reaction involving single functional groups. In the first protocol, an aminoalkylsilane was covalently linked to the Ti oxide layer, followed by covalent binding of glutaric anhydride to the free NH(2) groups. The carboxylic group of glutaric anhydride was used to condense the free N-terminal group of the side-chain protected peptide sequence. Finally, the surface was treated with trifluoroacetic acid to deprotect side-chain groups. In the second protocol, the peptide was directly anchored to the Ti oxide surface via UV activation of an arylazide peptide analogue. X-ray photoelectron spectroscopy analyses confirmed that modifications induced onto surface composition were in agreement with the reactions performed. The peptide density of each biomimetic surface was determined on the basis of radiolabeling and XPS derived reaction yields. The in vitro cellular response of the biomimetic surfaces was evaluated using a primary human osteoblast cell model. Cell adhesion, proliferation, differentiation, and mineralization were examined at initial-, short-, and long-time periods. In was shown that the biomimetic surface obtained through photoprobe-marked analogue that combines an easily-performed modification provides a favorable surface for an enhanced cellular response.

Biochemical surface modifications to titanium implants using the tresyl chlorideactivated method

“…Covalent immobilization using silane coupling reagents has been widely employed to immobilize cell adhesive proteins [8][9][10][11][12][13] . For example, heparin was grafted onto titanium surfaces using 3-aminopropyltriethoxysilnae and bone morphogenic protein (BMP)-2 was then immobilized onto the heparingrafted titanium surfaces 14) .…”

Bone response of TGF-β2 immobilized titanium in a rat model

“…TGF-β2 could be easily immobilized onto titanium by using the tesyl chloride-activation technique and enhancement of bone formation was recognized with TGF-β2/Ti. For the immobilization of proteins onto titanium, silane coupling agents have been widely employed [29][30][31][32] . However, the use of silane coupling agents requires multiple steps of treatment, for example, acidic pretreatment of the titanium surface and a condensation reaction between silane coupling agents and proteins.…”

Effects of Ti surface treatments with silane and arginylglycylaspartic acid peptide on bone cell progenitors

“…Previous studies have indicated that surface chemical composition and morphology of dental implant affect osseointegration [3]. Surface modifications can be categorized into two types: alteration of the surface morphology and grafting with biological proteins [4]. Different types and amounts of adsorbed proteins would dynamically change when the surface is in contact with biological solutions.…”

“…Numerous studies have focused on using various surface treatments, such as altering the surface hydrophobicity and hydrophilicity, surface charge, roughness, and microstructure, to modify the physicochemical surface properties of dental implants [2,[4][5][6]. Alternatively, biochemical modifications can be used to graft specific proteins, such as collagen, peptides, or genetically modified carriers, on dental implant surfaces by bioactive ceramic coatings, silane treatments, and protein/peptide coatings to reduce the time required for osseointegration, enhance the initial stability of dental implant, and increase long-term success rate [5][6][7][8].…”