An Asymmetric Zn Membrane with Degradability, Antimicrobial, and Bone Immunomodulation for Guided Bone Regeneration

As a biodegradable metal, zinc (Zn) offers a promising material option for barrier membranes in the field of bone regeneration due to its suitable degradation rate and mechanical properties. An ideal barrier membrane not only blocks the growth of epithelial fibers but also promotes bone regeneration. Therefore, we prepared an asymmetric Zn membrane with micrometer-sized pores on one side by laser etching, with the pore side facilitating cell adhesion and proliferation, and the smooth side facilitating the blocking of epithelial cell growth entry. And the antimicrobial peptide GL13K (P1) was loaded onto the smooth surface of Zn by Zn-specific binding peptide (NCS) to resist postoperative bacterial infections, and the small intestinal submucosal hydrogel complex (SIS-P2), which was specifically loaded with Substance P (SP), was placed in the pores on the pore side to modulate the immunity and promote osteogenesis. This innovative asymmetric zinc barrier membrane (Zn-P1-SIS-P2 membrane) exhibited excellent mechanical, antimicrobial, and biocompatibility properties. More importantly, the Zn-P1-SIS-P2 membrane promotes macrophage polarization toward the M2 type, thereby promoting osteogenic differentiation and providing a good immune microenvironment for bone regeneration. In addition, the Zn-P1-SIS-P2 membrane inhibited RANKL-induced osteoclast formation and suppressed bone resorption at the site of bone defects. In conclusion, the Zn-P1-SIS-P2 membrane demonstrated all the desirable qualities of a GBR therapeutic barrier membrane.