Chitosan coating as an antibacterial surface for biomedical applications

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Infectious Disease Prevention

Background:

• Post-surgical complications, such as infections, pose a significant public health challenge.
• Developing effective antibacterial implants is crucial for preventing these complications.

Purpose of the Study:

• To evaluate the antibacterial activity of animal-free chitosan grafted onto a titanium alloy.
• To confirm successful chitosan immobilization on the titanium alloy surface.

Main Methods:

• Chitosan was grafted onto a titanium alloy using TriEthoxySilylPropyl Succinic Anhydride (TESPSA) as a coupling agent.
• Surface characterization was performed using X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight secondary ion mass spectrometry (ToF-SIMS), and Dynamic-mode Secondary Ion Mass Spectrometry (DSIMS).
• Antibacterial activity was assessed against Escherichia coli and Staphylococcus aureus by quantifying colony-forming units (CFU).

Main Results:

• XPS confirmed a significant increase in carbon and nitrogen atomic percentages, indicating successful chitosan grafting.
• ToF-SIMS and DSIMS analyses validated the formation of a thick chitosan polymer layer on the titanium alloy.
• The developed coating demonstrated significant antibacterial activity against both Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria.

Conclusions:

• The study successfully immobilized animal-free chitosan onto a titanium alloy using established surface chemistry techniques.
• The resulting chitosan-coated titanium alloy exhibited potent antibacterial properties against key pathogenic bacteria.
• This approach offers a promising strategy for developing antibacterial implants to mitigate post-surgical infections.