Yuan Ha, Jie Yang, Fei Tao, Qian Wu, Yunjia Song, Haorong Wang, Xu Zhang*, Peng Yang*. Phase-Transited Lysozyme as a Universal Route to Bioactive Hydroxyapatite Crystalline Film. Adv. Funct. Mater. in press (adfm.201704476). Yuan Ha and Jie Yang contributed equally to this work.
A key factor for successful design of bioactive complex, organic-inorganic hybrid biomaterials is the facilitation and control of adhesion at the interfaces, as many current synthetic biomaterials are inert, lacking interfacial bioactivity. In this regard, the development of a simple, unified way to biofunctionalize diverse organic and inorganic materials towards biomineralization remains a critical challenge. In this report, a universal biomimetic mineralization route that can be applied to virtually any type and morphology of scaffold materials was provided to induce nucleation and growth of hydroxyapatite (HAp) crystals based on the Phase-Transited Lysozyme (PTL) coating. Surface-anchored abundant functional groups in the PTL enrich the interface with strongly bonded calcium ions, facilitating the formation of HAp crystals in simulated body fluid (SBF) with the morphology and alignment being similar to that observed in natural HAp in mineralized tissues. Inspired by the adhesion mechanism of amyloid structure contained in the PTL, such protein assembly could readily integrate HAp on ceramics, metals, semiconductors, and synthetic polymers irrespective of their size and morphology, with robust bonding stability and corresponding ultralow wear extent under normal bone pressure. This bottom-up crystal construction successfully improves the osteoconductivity of Ti-based implant in rat model, underpinning the expectation for such biomaterial in future biointerface and tissue engineering.