Endowing polyetheretherketone with synergistic bactericidal effects and improved osteogenic ability

Area of Science:

• Biomaterials Science
• Infectious Diseases
• Nanotechnology

Background:

• Biomedical associated infections (BAI) pose a significant threat, exacerbated by antibiotic-resistant bacteria, leading to severe complications including amputation and death.
• Polyetheretherketone (PEEK) is a widely used biomaterial, but its susceptibility to bacterial colonization and infection necessitates advanced protective strategies.
• Developing effective antimicrobial coatings for medical implants is crucial to prevent and treat BAI.

Purpose of the Study:

• To engineer a multifunctional coating for PEEK implants that synergistically combines multiple bactericidal agents for comprehensive eradication of planktonic and adherent bacteria.
• To create a 'smart' coating capable of releasing antimicrobial agents in response to the acidic environment typically found during infection.
• To evaluate the biocompatibility and osteogenic potential of the developed coating.

Main Methods:

• Fabrication of a mussel-inspired coating incorporating silver nanoparticles (AgNPs) and gentamicin sulfate (GS) onto a porous PEEK surface.
• Assessment of bactericidal efficiency against both Gram-positive and Gram-negative bacteria, quantifying reductions in surviving planktonic and adhered bacteria.
• Investigation of the pH-dependent release kinetics of Ag+ and GS, and evaluation of cytocompatibility and osteogenic ability.

Main Results:

• The AgNPs/SF/GS coating demonstrated a remarkable 10^6-fold reduction in surviving planktonic bacteria and a 10^5-fold reduction in adhered bacteria compared to untreated PEEK.
• The coating exhibited 'smart' functionality, with increased release of Ag+ and GS at lower pH, indicating bacteria-triggered self-defense.
• The functionalized PEEK exhibited favorable cytocompatibility and osteogenic potential, alongside potent antimicrobial activity.

Conclusions:

• The developed mussel-inspired, AgNPs/SF/GS coating provides a synergistic bactericidal effect, significantly enhancing PEEK's resistance to bacterial infections.
• The 'smart' pH-responsive nature of the coating offers targeted antimicrobial delivery, crucial for combating BAI.
• This dual-function coating presents a promising strategy to improve the clinical performance of PEEK implants and address the challenge of increasingly severe BAI.