Micro-patterned hydroxyapatite/silk fibroin coatings on Mg--Zn--Y--Nd--Zr alloys for better corrosion resistance and cell behavior guidance

In this study, a micro-patterned hydroxyapatite/silk fibroin (HA-SF) coating was firstly fabricated on the surface of Mg–Zn–Y–Nd–Zr alloy by template-assisted electrospraying technique coupling with spin coating technique. Two types of micro-patterns were achieved with high contour accuracy, namely HA-SF(line-pattern) and HA-SF(dot-pattern). The microstructure, composition, surface wettability and corrosion behaviors of the coatings were investigated by SEM, EDS, FTIR, XRD, water contact angle and potentiodynamic polarization test. The results revealed the hydrophilic nature of coatings and two orders of magnitude reduction of corrosion density (i_corr) as compared with that of the substrate. All the micro-patterned surfaces promoted the attachment of MC3T3-E1 cells with visible filopodia after 1 d incubation. In addition, coatings with line pattern exhibited the superior guidance to cell migration as compared to dot pattern, and the preference of cell attachment in the convex zone was observed. In summary, the obtained micro-patterned HA-SF coatings possessed the remarkably improvement of anticorrosion ability and good efficacy in guidance of cell attachment and alignment, which can serve as a promising strategy for cellular response modulation at the interface of magnesium-based implants and bone.