Using sodium tetraborate as electrolyte, a porous titania (TiO2) coating with a novel morphology of cortex-like slots was successfully prepared on the Ti surface through micro-arc oxidation (MAO). The effect of MAO treating time on surface layer was investigated. In this paper, we compared the cortex-like coatings with the conventional volcanic coatings. Results show that the cortex-like coatings with interconnected pores and slots have better wettability than volcanic coatings. The cell responses of TiO2 coatings, examined by culturing MG-63 cells on the samples, revealed that both cortex-like coating and volcanic coating presented good cell attachment after culturing for 1, 5 and 7 days, suggesting good biocompatibility. However, the cell growth of cortex-like coating occurred with cell ingrowth into the deep slots, which is different from that of the conventional volcanic coating. Results of this study indicated that the cortex-like coating was conducive to cell retention and implant stabilization. (c) 2012 Elsevier B.V. All rights reserved.