Sculpting Bio-Inspired Surface Textures: An Adhesive Janus Periosteum

Existing artificial periostea faces difficulty in supporting the entire bone repair cycle due to the absence of adhesion-centric design and effective cell manipulation, leading to poor inhibition of soft tissue infiltration and induction of osteogenesis and angiogenesis. Here, a Janus periosteum with interior surface adhesion and exterior anatomical patterns to mimic the structure and function of natural periosteum is presented. Photo-crosslinkable polymers are employed to replicate the exterior anisotropic surface structured microgrooves for cell fate manipulation and assemble gecko-inspired fibrillar setae arrays for interior surface adhesion. To further bolster its underwater adhesiveness, mussel-inspired poly (dopamine methacrylamide-co-hydroxyethyl methacrylate) (PDMH) is coated onto the periosteum surfaces. This periosteum presents adhesiveness with strong shear and normal adhesion in both dry and wet conditions due to the coordinated interactions of micro setae arrays and PDMH coating; it also boasts effective cell modulation for enhanced synchronous osteogenesis and angiogenesis, without the aid of growth factors. Moreover, the Janus periosteum is found to enhance bone regeneration in vivo with increased new bone formation and neovascularization. It is envisioned that this Janus periosteum will be able to streamline bone fracture surgical repair as a rapidly adhesive, low-maintenance yet robust bandage to significantly cut down the healing phase.