Electrodeposited biodegradable Zn-Fe alloy foams: Synergistic control of degradation kinetics and biomechanical properties for cranial bone implants.

Abstract

Critical-sized craniocerebral defects pose significant reconstruction challenges due to inadequate self-repair capacity and limitations of autologous bone grafts. Addressing this, we pioneer biodegradable Zn-Fe alloy foams fabricated via dual-anode co-deposition, which overcomes elemental segregation in conventional gradient-coated foams, to achieve integrated mechanical and degradation properties. By tailoring deposition current (0.4-0.6 A), electrolyte pH (2.8-3.0), and temperature (25-35 °C), this study establishes a critical link between process-induced microstructural evolution and the resultant scaffold performance in critical-sized cranial defect repair. Key results demonstrate: current-induced densification and pH-mediated defect control enable mechanically-optimized architectures with Plastic Collapse Stress (PCS, 151 ± 6 kPa) and Compressive Young's Modulus (CYM, 500 ± 19 kPa). Degradation kinetics self-regulate physiological pH (7.5-8.0) via mineralized byproducts (Ca₃Fe₂(OH)₁₂/Zn(OH)₂), with degradation rates tunable to 17.67-44.14 mm/y while sustaining >95 % osteoblast viability through controlled Zn²⁺/Fe³⁺ release (1.20-1.69/0.25-0.73 mg/L). The 0.5 A/pH = 3.0/30 °C parameters emerge as a clinically translatable solution, concurrently satisfying cranial bone-matching degradation, biomechanics, and biocompatibility.