Ciprofloxacin-Loaded Polyaniline and Biopolymer Coatings on Magnesium Alloys: New Insights for Enhanced Corrosion Resistance and Osteointegration Performance

Abstract

Implant failure due to infection and poor osseointegration is a major challenge in orthopedic surgery. Developing implant surfaces with long-lasting antimicrobial effects while maintaining bioactivity and mechanical strength is complex. Magnesium (Mg) alloys are promising bone implants due to their excellent biocompatibility and natural degradation in the body. However, their rapid corrosion rate and susceptibility to infections limit clinical use. Drug-loaded polymer composite coatings on Mg alloy surfaces offer a potential solution. This study explores polyaniline-based coatings to enhance mechanical properties and corrosion resistance, while egg albumin and leucine coatings aim to improve biocompatibility. Ciprofloxacin (CIP)-loaded coatings are developed to enhance antibacterial properties and promote cell growth. Coatings are fabricated using electrophoretic deposition (EPD) and dip-coating. The process includes anodizing Mg alloys to form a MgO layer, followed by electrodeposition of Polyaniline and Triethylamine (PANI-TEA), dip-coating with biopolymer and amino acid, and incorporating ciprofloxacin. Characterization techniques such as ATR-FTIR, XRD, FE-SEM, and EDX confirm the coatings' formation and structure. These coatings exhibit strong mechanical properties, excellent corrosion resistance, antimicrobial effects, and good biological compatibility. In vitro tests show significant bone cell adhesion and growth on PANI-TEA/EA-Leu-3 coated MgO composites, suggesting effective prevention of osteomyelitis and promotion of bone healing.

Keywords: Magnesium alloys, Polyaniline-based coatings, Ciprofloxacin-loaded coatings, Corrosion resistance, Osteointegration