Bionic manufacturing strategy of hydroxyapatite-coated polyether ether ketone scaffolds for promoting mineralization and osseointegration

Porous polyether ether ketone (PEEK) scaffolds with hydroxyapatite (HA) layer coated on the pore wall surface were prepared using sacrificial porogen of HA-coated sodium chloride (NaCl) microspheres. The manufacture of bionic porogen was structurally inspired by the Chinese traditional food Matuan, which is a glutinous rice ball stuck with sesames. Spherical-shaped NaCl@HA microspheres with a uniform size facilitated the generation of an interconnected porous PEEK@HA scaffold with a HA coating layer on the pore surface. And the mechanical properties of PEEK@HA scaffolds were not affected by the coating layer of HA compared with PEEK porous scaffolds. After immersing in simulated body fluid and transplanting in rat proximal tibia, the PEEK@HA porous implants possessed superior in vitro biomineralization and in vivo osseointegration due to the favorable environment of the HA layer for bone ingrowth. This facile manufacturing strategy provides a unique perspective to integratedly fabricate bionic porous PEEK scaffolds with a mineralized coating layer enhancing the osseointegration of PEEK materials with bony tissue interfaces in orthopedics and stomatology. It also presents a general platform for further creating multifunctional porous PEEK implants, such as antibacterial, immunomodulatory, and photothermal therapy, by coating various inorganic nanoparticles with desired characteristics on the pore wall surface.