Novel Palladium Hydride Surface Enabling Simultaneous Bacterial Killing and Osteogenic Formation through Proton Capturing and Activation of Antioxidant System in Immune Microenvironments

• Published in: Advanced materials (Weinheim) 2024-08, Vol.36 (31), p.e2404485-n/a
• Main Authors: Zhang, Dongdong, Li, Mei, Chen, Shuhan, Du, Huihui, Zhong, Hua, Wu, Jun, Liu, Feihong, Zhang, Qian, Peng, Feng, Liu, Xuanyong, Yeung, Kelvin W.K.
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antioxidants; Antioxidants - chemistry; Antioxidants - metabolism; Antioxidants - pharmacology; Bacteria; bacterial killing; Disruption; enzyme‐like activity; Humans; Hydrides; Hydrogen - chemistry; Hydrogen - metabolism; Immune system; Osteogenesis - drug effects; osteogenic immune microenvironment; Oxidative Stress - drug effects; Palladium; Palladium - chemistry; palladium hydride film; Proton transfer; Protons; Reactive Oxygen Species - metabolism; Regeneration (physiology); Surface Properties; Tissue engineering
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202404485

Achieving bacterial killing and osteogenic formation on an implant surface rarely occurs. In this study, a novel surface design–a palladium hydride (PdHx) film that enables these two distinct features to coexist is introduced. The PdHx lattice captures protons in the extracellular microenvironment of bacteria, disrupting their normal metabolic activities, such as ATP synthesis, nutrient co‐transport, and oxidative stress. This disruption leads to significant bacterial death, as evidenced by RNA sequence analysis. Additionally, the unique enzymatic activity and hydrogen‐loading properties of PdHx activate the human antioxidant system, resulting in the rapid clearance of reactive oxygen species. This process reshapes the osteogenic immune microenvironment, promoting accelerated osteogenesis. These findings reveal that the downregulation of the NOD‐like receptor signaling pathway is critical for activating immune cells toward M2 phenotype polarization. This novel surface design provides new strategies for modifying implant coatings to simultaneously prevent bacterial infection, reduce inflammation, and enhance tissue regeneration, making it a noteworthy contribution to the field of advanced materials. A palladium hydride (PdHx) film, fabricated on titanium implants, exhibits a lattice capable of capturing protons within the bacterial microenvironment, consequently inducing bacterial death. Furthermore, it mimics human antioxidant systems, reshaping the osteogenic immune microenvironment and promoting osteogenesis.