Sandwich-like chitosan/collagen barrier membrane with passivated magnesium mesh as the skeleton

Guided bone regeneration (GBR) technique is a standard therapy for reconstructing alveolar bone defects clinically, with the GBR membrane serving as the key medical device in this technique. However, the most commonly used collagen barrier membranes usually have poor mechanical properties and are prone to collapse during clinical use. Herein, a sandwich-like barrier membrane was developed with crosslinked chitosan as dense layer, crosslinked collagen as loose layer and passivated magnesium mesh as the skeleton. Surface modification has improved the corrosion resistance of magnesium mesh. Thanks to the introduction of magnesium mesh skeleton and crosslinking modification, the mechanical properties and supporting effects of barrier membrane have been improved. The dense layer of barrier membrane showed dense structure while the loose layer showed porous structure as expected. The barrier membrane showed good antibacterial performance against gram-positive and gram-negative bacteria owing to the antibacterial activity of chitosan and the added chlorhexidine acetate. Furthermore, the barrier membrane met the requirements of biocompatibility for implanted biomaterials. Interestingly, the barrier membrane had good anti-inflammatory activity to accelerate the transition from inflammatory to proliferative stage and can promote osteogenic differentiation of MC3T3-E1 cells. Overall, the sandwich-like barrier membrane has a wide application prospect to guide bone regeneration.