Copper as an alternative antimicrobial coating for implants - An in vitro study

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Surface Chemistry

Background:

• Orthopedic implants are susceptible to bacterial colonization and biofilm formation, leading to complications.
• Developing effective antimicrobial surface coatings is crucial for improving implant success rates.
• Titanium-based coatings offer potential for enhanced biocompatibility and antimicrobial properties.

Purpose of the Study:

• To evaluate the osteoconductive and antimicrobial properties of a titanium-copper-nitride (TiCuN) film, with and without an additional BONIT® coating, on titanium substrates.
• To assess the impact of these coatings on osteoblast behavior and bacterial growth.
• To understand the ion release dynamics and surface characteristics of the coated titanium samples.

Main Methods:

• Titanium substrates were micro-structured using titanium plasma spray (TPS).
• TiCuN and BONIT® layers were applied via physical vapor deposition and electrochemical coating, respectively.
• Copper ion release was quantified using atomic absorption spectrometry, while cell adhesion, viability, and spreading of MG-63 osteoblasts and Staphylococcus epidermidis were analyzed.

Main Results:

• TiCuN coatings demonstrated rapid release of copper ions, leading to complete inhibition of Staphylococcus epidermidis growth and biofilm formation within 2 days.
• Initial direct cultivation of MG-63 osteoblasts on TiCuN impaired viability, but pre-incubation significantly enhanced cell colonization and spreading.
• The additional BONIT® coating reduced copper ion release and positively influenced initial osteoblast adhesion.

Conclusions:

• The TiCuN coating effectively inhibits bacterial biofilm formation on orthopedic implants.
• The coating influences the "race for the surface" dynamics, favoring osteoblast colonization after appropriate pre-incubation.
• TiCuN and BONIT® coatings present a promising strategy for developing advanced orthopedic implant surfaces with combined antimicrobial and osteoconductive properties.