Phosphonate/quaternary ammonium copolymers as high-efficiency antibacterial coating for metallic substrates

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Engineering

Background:

• Bacterial infections are a significant risk for metallic implants.
• Developing effective antibacterial coatings is crucial for medical devices.

Purpose of the Study:

• To develop and characterize novel metal-anchorable antibacterial coatings.
• To investigate the relationship between copolymer composition and antibacterial efficacy.

Main Methods:

• Random radical polymerization to synthesize phosphonate/quaternary ammonium copolymers (p(DEMMP-co-TMAEMA)).
• One-step coating of copolymers onto titanium alloy (TC4) substrates via covalent phosphonate bonding.
• XPS and water contact angle tests to confirm substrate bonding.
• Evaluation of bactericidal activity against S. aureus and E. coli.
• Cytotoxicity assessment using C2C12 cells.

Main Results:

• Copolymers successfully anchored to TC4 substrates with as little as 6.3% pDEMMP content.
• Antibacterial efficacy increased with higher pTMAEMA content, reaching 98.8% for S. aureus and 99.4% for E. coli.
• Coatings demonstrated limited cytotoxicity to C2C12 cells.
• The coating method was effective on various biomedical metals (Ti, SS, Ni/Cr alloys).

Conclusions:

• Phosphonate/quaternary ammonium copolymers offer a versatile and efficient antibacterial coating solution.
• The developed coatings provide robust, long-lasting antibacterial properties for metallic implants.
• This technology has broad applicability across different biomedical metal substrates.