Biomimetic metal-phenolic network with cyclolactam hydrogel coating on PPENK implant facilitate bone repair

Bone defects are often accompanied by infection, which causes great physical pain to patients. Metal-phenolic networks (MPNs) are a newly organic–inorganic hybrid networks system, which has become a multifunctional surface modifier based on the universal adhesion properties of phenolic molecules. Hence, we fabricate a MPN hydrogel coating based on cyclolactam network by spin-coating a mixture of gelatin, iron ions, and polyphenol monomer containing phthalazinone structure (THPZB) on the surface of poly(aryl ether nitrile ketone) (PPENK) (G/THPZB/Fe/PPENK). The method can easily obtain a high strength and versatile surface hydrogel coating based on the combination of the entangled structure on phthalazinone and the characteristic functions of MPNs. The residual polyphenol on the surface not only confer good adhesion ability, but also can cooperate with lactam ring to confer outstanding antibacterial ability to the PPENK implant. Importantly, the antibacterial mechanism of this modified PPENK implant might be consistent with that of penicillin. Besides, it has excellent ability to promote angiogenesis and healing in vitro. Notably, significant effects on biomineralization and osteogenesis in vitro and in vivo are observed. We hypothesis that cyclolactam-based MPN multifunctional hydrogel coating can provide great application prospects for PPENK bone implant materials in the field of bone defect repair.