Biodegradable Magnesium alloy Janus membrane with surface-selective osteoinduction and soft tissue healing properties...

Given that the guided bone regeneration (GBR) membrane acts at the interface between the bone and connective tissue, the membrane imposes high demands on the organization of the material. Magnesium (Mg) alloys have emerged as promising candidates for GBR due to their biodegradability and favorable biocompatibility. However, challenges remain in the risk of soft tissue dehiscence and limited osteogenesis for Mg membranes in the clinical application. A dicalcium phosphate dihydrate (CaHPO₄·2H₂O, denoted as DCPD)/MgF₂ Janus membrane was fabricated via chemical conversion and deposition, showcasing suitable degradability, surface-selective osteogenic property and soft tissue healing in vitro and vivo. The DCPD coating was designed to support osteogenesis, while the MgF₂ coating was specifically engineered to facilitate soft tissue healing. Furthermore, the Janus membrane utilized its two-sided properties to show selectivity in adhesion, proliferation, and migration of the MC3T3-E1 and HGFs. In vivo results exhibited its capability to promote bone formation and optimal space maintenance ability. Notably, further RNA-seq analysis demonstrated that different functional cells may respond specifically to two coatings and exert functions. Taken together, these results provide an alternative method for designing surface-selective biomaterials, underlining effective potential applications in bone tissue engineering. STATEMENT OF SIGNIFICANCE: Traditional clinical treatment of bone defects with GBR membranes is frequently constrained to a single superimposed osteogenesis without structural-functional integration. Such a DCPD/MgF₂ coated Janus membrane was fabricated by incorporating chemical deposition and transformation to satisfy optimal osteogenesis and soft tissue healing. Of particular interest, the Janus membrane allowed for chemotactic movement with specific cellular responses to stimuli from different coatings. In vivo, the membrane demonstrated promising effects and showcased space maintenance ability. The design concept exhibits a new avenue to regulate tissue regeneration between different tissue interface, presenting new horizons for the development of GBR membranes.