Bioinspired triple-layered membranes for periodontal guided bone regeneration applications

Barrier membranes have been used for the treatment of alveolar bone loss caused by periodontal diseases or trauma. However, an optimal barrier membrane must satisfy multiple requirements simultaneously, which are challenging to combine into a single material. We herein report the design of a bioinspired membrane consisting of three functional layers. The primary layer is composed of clay nanosheets and chitin, which form a nacre-inspired laminated structure. A calcium phosphate mineral layer is deposited on the inner surface of the nacre-inspired layer, while a poly(lactic acid) layer is coated on the outer surface. The composite membrane integrates good mechanical strength and deformability because of the nacre-inspired structure, facilitating operations during the implant surgery. The mineral layer induces the osteogenic differentiation of bone marrow mesenchymal stem cells and increases the stiffness of the membrane, which is an important factor for the regeneration process. The poly(lactic acid) layer can prevent unwanted mineralization on the outer surface of the membrane in oral environments. Cell experiments reveal that the membrane exhibits good biocompatibility and anti-infiltration capability toward connective tissue/epithelium cells. Furthermore, in vitro analyses show that the membrane does not degrade too fast, allowing enough time for bone regeneration. In vivo experiments prove that the membrane can effectively induce better bone regeneration and higher trabecular bone density in alveolar bone defects. This study demonstrates the potential of this bioinspired triple-layered membrane with hierarchical structures as a promising barrier material for periodontal guided tissue regeneration.