Mechanochemically Reprogrammed Interface Orchestrates Neutrophil Bactericidal Activity and Apoptosis for Preventing Implant‐Associated Infection

Abstract

The onset of implant‐associated infection (IAI) triggers a cascade of immune responses, which are initially dominated by neutrophils. Bacterial aggregate formation and hypoxic microenvironment, which occur shortly after implantation, may be two major risk factors that impair neutrophil function and lead to IAI. Here, the implant surface with phytic acid–Zn2+ coordinated TiO2 nanopillar arrays (PA–Zn@TiNPs) and oxygen self‐supporting CaO2 nanoparticles, named as CPZTs, is mechanochemically reprogrammed. The engineered CPZTs interface integrates multiple properties to inhibit the formation of nascent biofilm, encompassing antibacterial adhesion, mechanobactericidal effect, and chemobiocidal effect. Meanwhile, continuous oxygenation fuels the neutrophils with reactive oxygen species (ROS) for efficient bacterial elimination on the implant surface and inside the neutrophils. Furthermore, this surface modulation strategy accelerates neutrophil apoptosis and promotes M2 macrophage‐mediated osteogenesis both in vitro and in a rat model of IAI. In conclusion, targeting neutrophils for immunomodulation is a practical and effective strategy to prevent IAI and promote bone–implant integration.

Smart responsive staple for dynamic promotion of anastomotic stoma healing

“…For example, antibacterial agents such as antibiotics, metal ions, metal oxides, and antimicrobial peptides are highly effective, but their use may inhibit cell proliferation and lead to drug resistance over time ( Fig. 1 b) [ [16] , [17] , [18] ]. Conversely, bioactive molecules such as miR-21, BMP-2, gelatin-CaPO, and MOFs, incorporated into titanium materials can promote cell proliferation but lack antibacterial and anti-inflammatory properties, which can lead to bacterial adhesion and proliferation during the early phases of tissue repair [ [19] , [20] , [21] ].…”