Antimicrobial Electrodeposited Silver-Containing Calcium Phosphate Coatings

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Nanotechnology

Background:

• Orthopedic implant infections pose a significant clinical challenge, necessitating advanced antimicrobial strategies.
• Biocompatible coatings containing minerals native to bone, like hydroxyapatite, and antimicrobial agents such as silver, are crucial for enhancing implant functionality.
• Electrochemical deposition offers precise control for creating complex coatings on titanium substrates.

Purpose of the Study:

• To develop and compare two silver-containing calcium phosphate (Ag/Ca-P) coatings fabricated via electrochemical deposition.
• To evaluate the antimicrobial efficacy and biocompatibility of one-step (Ag/Ca-P(1)) and two-step (Ag/Ca-P(2)) deposition methods.
• To assess the impact of preincubation in phosphate-buffered saline on coating performance.

Main Methods:

• Electrochemical deposition of Ag/Ca-P coatings on titanium substrates using one-step and two-step approaches.
• Characterization of coatings for silver ion leaching and nanoparticle formation.
• Assessment of bacterial reduction through Ag-ion leaching and contact killing mechanisms.
• Evaluation of osteoblast cytotoxicity and overall biocompatibility.

Main Results:

• The Ag/Ca-P(1) coating achieved 76.1 ± 8.3% bacterial reduction via ion leaching; Ag/Ca-P(2) achieved 83.7 ± 4.5% via contact killing.
• Preincubation in phosphate-buffered saline significantly enhanced bacterial reduction to 97.6 ± 2.7% (Ag/Ca-P(1)) and 99.7 ± 0.4% (Ag/Ca-P(2)) due to AgCl species leaching.
• Ag/Ca-P(1) coatings exhibited cytotoxicity towards osteoblasts, whereas Ag/Ca-P(2) coatings demonstrated excellent biocompatibility.

Conclusions:

• The two-step electrochemical deposition method (Ag/Ca-P(2)) yields highly bactericidal coatings with excellent biocompatibility.
• These Ag/Ca-P(2) coatings show significant potential for preventing infections in orthopedic implants, including those with complex geometries.
• Further development of these coatings could revolutionize infection control in bone implant applications.