A multifunctional collagen-base bilayer membrane integrated with a bimetallic/polydopamine network for enhanced guided bone regeneration

The guided bone regeneration (GBR) technique is an effective treatment for small and medium-sized bone defects in the oral and maxillofacial region. However, currently available collagen membranes have limited functionality and are inadequate for clinical requirements. To address this challenge, this study pioneeringly developed a multifunctional bilayer membrane. Specifically, a bimetallic/polydopamine network (BPN), consisting of silver, magnesium, and dopamine, was successfully synthesized for the first time and integrated with collagen and hydroxyapatite. The resulting material was characterized, and its physicochemical properties, along with its barrier, osteogenic, angiogenic, antibacterial, hemostatic, and biosafety effects, were evaluated through both in vitro and in vivo studies. The results indicated that the BPN, composed of magnesium ions, silver nanoparticles (Ag NPs), and polydopamine (PDA), exhibited excellent thermal stability and slow release of silver and magnesium elements. The BPN/Col-HA membrane featured a bilayer structure with uniform distribution of silver and magnesium. It also demonstrated good hydrophilicity, suitable degradation and mechanical properties, as well as sustained release of silver and magnesium. In vitro experiments showed that the BPN/Col-HA membrane possessed desirable barrier, osteogenic, angiogenic, antibacterial, hemostatic, and biocompatible properties. In vivo results further confirmed its biosafety, hemostatic efficacy, and ability to effectively promote bone defect repair and angiogenesis. Thus, the BPN/Col-HA membrane emerges as a multifunctional GBR membrane with potential for clinical translation.