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Updated: Sep 11, 2025
Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo
Published on: July 1, 2013
pH-modulated electrostatic steering enhances SPAAC-mediated peptide grafting on titanium implants
Ru Zhong1, Gaosheng Zhang2, Lin Wang1
1National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China; School of Material Science and Engineering, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006, China.
Peptide charge significantly impacts surface grafting efficiency on titanium. Cationic peptides bind well to negatively charged surfaces, while anionic peptides require pH adjustments for optimal binding, enabling versatile implant functionalization.
Area of Science:
- Biomaterials Science
- Surface Chemistry
- Peptide Chemistry
Background:
- Titanium-based implants require surface functionalization for enhanced biocompatibility and therapeutic delivery.
- Strain-promoted azide-alkyne cycloaddition (SPAAC) is a bioorthogonal click chemistry reaction for surface modification.
- Peptide grafting efficiency is crucial for successful implant functionalization.
Purpose of the Study:
- To investigate the influence of peptide charge states on SPAAC-mediated grafting efficiency onto titanium-based substrates.
- To determine optimal conditions for grafting both cationic and anionic peptides.
- To develop a pH-tuned strategy for universal surface functionalization of titanium implants.
Main Methods:
- Utilized SPAAC click chemistry for peptide grafting.
- Employed titanium-based substrates functionalized with dibenzocyclooctyne (DBCO).
- Investigated the effect of peptide charge (cationic vs. anionic) and solution pH on grafting efficiency.
Main Results:
- Cationic peptides showed high grafting efficiency in neutral aqueous conditions due to electrostatic attraction to negatively charged DBCO surfaces.
- Anionic peptides exhibited low grafting efficiency at neutral pH but significantly improved binding at lower pH.
- pH modulation effectively reversed charge disparities, enabling efficient grafting of anionic peptides.
Conclusions:
- Peptide charge state is a critical determinant of SPAAC grafting efficiency on titanium.
- A pH-tuning strategy allows for controlled and efficient grafting of diverse therapeutic peptides onto titanium-based implants.
- This approach facilitates universal surface functionalization for advanced biomedical applications.
