Evaluating protein binding specificity of titanium surfaces through mass spectrometry-based proteomics

Area of Science:

• Biomaterials Science
• Proteomics
• Surface Chemistry

Background:

• Surface characteristics of dental implants influence biological interactions.
• Salivary pellicle formation is a critical early step in osseointegration.
• Understanding protein adsorption on titanium is key for improving implant success.

Purpose of the Study:

• To investigate how different titanium surface modifications affect salivary pellicle composition.
• To analyze the salivary proteome adsorbed onto various titanium surfaces using mass spectrometry.
• To determine the surface specificity of protein binding on modified titanium.

Main Methods:

• Characterization of titanium discs (machined, SLA, SLActive) for topography, chemistry, and energy.
• Incubation of titanium discs in saliva for 2 hours to form a salivary pellicle.
• Analysis of the adsorbed protein layer using liquid chromatography-electrospray ionization tandem mass spectrometry (nLC-ESI-MS/MS).

Main Results:

• Salivary pellicle composition was more complex on rougher titanium surfaces (SLA and SLActive).
• Limited surface specificity for protein binding was observed, with most proteins detected on multiple surfaces.
• The SLActive surface showed an increased number of proteins related to immune response, adhesion, and biomineralization.

Conclusions:

• Titanium surface topography, chemistry, and energy did not solely determine salivary pellicle specificity.
• Adsorbed salivary proteins on titanium surfaces play roles in essential biointegration functions.
• Development of bioactive surfaces promoting specific protein layers is necessary for enhanced tissue response and dental implant biointegration.