Biomimetic Surface Nanoengineering of Biodegradable Zn-Based Membranes Enables Phase-Specific Metal Ion Delivery for Synergistic Anti-Infection and Bone Regeneration.

Abstract

Guided bone regeneration (GBR) membranes that provide sound osteogenic activity while also providing effective bacteriostatic characteristics are an unmet therapeutic need for alveolar ridge enhancement. While biodegradable zinc (Zn)-based metals have tremendous potential as barrier membrane materials, their concentration-dependent duality of Zn²⁺ actions poses a crucial therapeutic problem. At low levels, Zn²⁺ shows constrained osteoinductive capabilities; at high levels, it has strong antibacterial effects but may reduce cell viability. To resolve this therapeutic paradox, we engineered a biomimetic polydopamine (PDA)-based nanohybrid coating with precisely controlled Cu²⁺ concentrations (0-0.2 mM) on pure Zn membranes. Our findings revealed three significant functional advantages of this membrane system: Broad-spectrum antibacterial effectiveness against bacterial microorganisms via synergistic Zn²⁺/Cu²⁺ release, damaging bacterial membranes and reducing biofilm formation. Mechanical stability resists deformation-induced microcracks while showing compatibility with the bone healing timeline. Ion release kinetics are phase-specific and adjust dynamically to bone healing stages, with quick initial release for infection control, cumulative release during osteogenesis/angiogenesis, and sustained release for mineralization. Its wide use is due to balanced degradation and ion levels, tackling infection, durability, and bone growth. This simple one-step method gives a practical, multifunctional solution for complex alveolar defects with easy scaling up.