Mechanochemically Reprogrammed Interface Orchestrates Neutrophil Bactericidal Activity and Apoptosis for Preventing...

Area of Science:

• Biomaterials Science
• Immunology
• Orthopedic Surgery

Background:

• Implant-associated infections (IAI) are a major complication, often initiated by bacterial factors impairing neutrophil function.
• Bacterial aggregation and hypoxia post-implantation are key risk factors for IAI development.

Purpose of the Study:

• To develop a novel implant surface (CPZTs) that modulates the host immune response to prevent IAI.
• To enhance neutrophil function and promote bone-implant integration.

Main Methods:

• Fabrication of TiO2 nanopillar arrays functionalized with phytic acid-Zn2+ and CaO2 nanoparticles (CPZTs).
• Evaluation of CPZTs' ability to inhibit biofilm formation, exhibit antibacterial adhesion, mechanobactericidal, and chemobiocidal effects.
• Assessment of CPZTs' impact on neutrophil function, apoptosis, and M2 macrophage-mediated osteogenesis in vitro and in vivo.

Main Results:

• Engineered CPZTs interface demonstrated multi-property inhibition of nascent biofilm formation.
• Continuous oxygenation from CPZTs enhanced neutrophil reactive oxygen species (ROS) production for bacterial elimination.
• Surface modulation accelerated neutrophil apoptosis and promoted M2 macrophage-mediated osteogenesis in vitro and in a rat IAI model.

Conclusions:

• Targeting neutrophils via immunomodulation is a viable strategy for preventing IAI.
• The developed CPZTs surface effectively prevents infection and promotes bone-implant integration.