A multifunctional polypyrrole/zinc oxide composite coating on biodegradable magnesium alloys for orthopedic implants

Magnesium (Mg) and its alloys exhibit great potential in clinical applications owing to the outstanding biological performance and excellent mechanical properties, whereas the quick corrosion rate in the physiological environment has limited their further clinical application. In this work, we designed and developed a multifunctional polypyrrole/zinc oxide (Ppy/ZnO) composite coating by cyclic voltammetry method, aiming to enhance the biocorrosion resistance, biocompatibility and antibacterial property of the Mg alloys. The electrochemical and immersion tests indicated that the corrosion resistance of the Mg alloy was improved significantly by the composite coating. A systematic in vitro investigation of cellular response confirmed that the composite coating significantly promoted the adhesion and proliferation of cells. In addition, the composite coating showed a remarkable antibacterial ability of 96.5 +/- 2.6 % against Escherichia coli (E.coli). The enhanced corrosion resistance, cytocompatibility, and antibacterial property of the Ppy/ZnO coated Mg alloy makes it a promising candidate as orthopedic implants material.