Biofunctionalization of a "clickable" organic layer photochemically grafted on titanium substrates

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Nanotechnology

Background:

• Titanium and its oxides are widely used in biomedical implants.
• Biofunctionalization is crucial for improving implant performance and biocompatibility.
• Existing surface modification methods can be complex and limited in scope.

Purpose of the Study:

• To develop a versatile and efficient method for biofunctionalizing titanium surfaces.
• To create a "clickable" platform for attaching biomolecules.
• To investigate the impact of surface modification on protein, cell adhesion, and cell spreading.

Main Methods:

• Photochemical grafting of an α,ω-alkenyne onto titanium dioxide/titanium (TiO(2)/Ti) substrates.
• Utilizing a trimethylgermanyl (TMG) protecting group for selective surface functionalization.
• Employing copper-catalyzed click chemistry for attaching oligo(ethylene glycol) (OEG) derivatives and GRGD peptides.
• Characterization using X-ray photoelectron spectroscopy (XPS), contact angle goniometry, ellipsometry, and atomic force microscopy (AFM).

Main Results:

• Successfully created a "clickable" thin film platform on titanium substrates.
• Demonstrated significant reduction in nonspecific protein and cell attachment on OEG-modified surfaces.
• Showcased the ability to coimmobilize OEG and GRGD peptides.
• Confirmed that GRGD-presenting surfaces promote specific adhesion and spreading of AsPC-1 cells.

Conclusions:

• The combined photochemical grafting and click chemistry approach offers a general and effective strategy for titanium surface biofunctionalization.
• The developed platform enhances biocompatibility by minimizing nonspecific interactions.
• The platform supports targeted cell adhesion and spreading, indicating potential for advanced biomedical applications.