Magnetically Assisted Electrodeposition of Aligned Collagen Coatings

Well-aligned collagen nanofibers are crucial in engineering bioinspired regenerative strategies, such as bone, muscle and cornea. However, keeping the natural bioactive of collagen and controlling its orientation in a coating still remain a challenge. Here we present a novel magnetically assisted electrochemical technique to deposit type-I collagen nanofibers with high alignment onto titanium. The magnetic assistance involved mainly the incorporation of iron oxide nanoparticles (IOPs) and the application of an external magnetic field during the electrochemical deposition. The combination of IOPs with the collagen nanofibrils in electrolyte endowed the nanofibrils with magnetism, which forced the collagen nanofibrils to be straightened and assembled into aligned nanofibers under magnetic field during electrodeposition. The influence of the applied magnetic field on orientational order of the collagen nanofibers in the coatings extended to drying stage. The aligned collagen coatings demonstrated to favorably guide the bone marrow mesenchymal stem cells (BMSCs) grow in the form of elongated morphology, which promoted the cellular osteogenic differentiation dramatically. The present magnetically assisted electrodeposition could emerge as an attractive approach to fabrication of aligned nanofibers on substrates for subsequent uses such as bone tissue engineering.