Building polyphenol and gelatin films as implant coating, evaluating from in vitro and in vivo performances

Bone related implants have huge potential market in global. Improving the implant outcomes and probability of implant success are highly pursued to relieve the pain of patients and burden on native healthy system. There are growing evidence to support reactive oxygen species (ROS) directly involved in bone diseases and failure of implants. Taking advantage of the antioxidant property of tannic acid (TA) and biocompatibility of gelatin (Gel), the TA/Gel multilayer film was fabricated by layer by layer method, and the growing process of this film was monitored by QCM-D. The physical properties of TA/Gel film were further well characterized and modulated. In cellular test, TA/Gel multilayer film displayed good antioxidant properties under ROS stress environment (after H₂O₂ treatment flourscence intensity increased 38.9-fold for glasses, only ˜6-fold for (TA/Gel)₈), facilitating cell attachment, fastening spreading at early stage and accelerating proliferation in beginning 2 day. Area per cell on (TA/ Gel)_4-0.15 M is 1.5-fold higher than that on glass at 2 h, while it became 2.3-fold higher at 4 h. Moreover, these films performed both enhanced osteogenesis in vitro test and bone formation in vivo in the animal bone implanting model. Our results supported discovered the antioxidant coating played the critical role one the success of bone related implants, which could be particularly noted in the future implant design. And the strategy applied here, utilizing the interactions between polyphenol and proteins to construct multilayer film, will pave the way to fabricating an antioxidant coating.