Silver-doped hydroxyapatite coatings formed on Ti-6Al-4V substrates and their characterization

Area of Science:

• Biomaterials Science
• Nanotechnology
• Infectious Disease Research

Background:

• Bacterial infections pose a significant risk for medical implants.
• Antibacterial coatings are crucial for preventing implant-associated infections.
• Hydroxyapatite (HA) coatings are biocompatible but can be enhanced with antimicrobial agents.

Purpose of the Study:

• To develop and evaluate hydroxyapatite (HA) coatings incorporating chitosan (CS) and silver (Ag) for enhanced antibacterial properties on Ti-6Al-4V substrates.
• To investigate the influence of chitosan surface modification on HA-Ag and HA-CS-Ag coating formation and antibacterial efficacy.
• To assess the impact of silver ions and chitosan on bacterial adhesion.

Main Methods:

• Ti-6Al-4V substrates were modified with a chitosan film.
• HA-CS-Ag coatings were prepared using a thermal substrate method at 90°C.
• Coated surfaces were analyzed using X-ray diffraction, scanning electron microscopy, and atomic absorption spectroscopy for silver content.

Main Results:

• Chitosan surface modification promoted the formation of HA-Ag and HA-CS-Ag coatings.
• The presence of silver ions inhibited bacterial adhesins, reducing E. coli adhesion by 14%.
• The combined action of silver ions and chitosan resulted in a 21% decrease in the bacterial adhesive index.

Conclusions:

• Chitosan-modified surfaces facilitate the formation of effective HA-Ag and HA-CS-Ag coatings.
• These novel coatings exhibit significant antibacterial activity against Escherichia coli.
• The synergistic effect of silver ions and chitosan offers a promising strategy for developing infection-resistant medical implants.