Chitosan (CS) coatings produced via electrophoretic deposition (EPD) have been widely applied to improve the bioactivity of implants, but the low-coating adhesion strength and water electrolysis during electrophoresis weaken the resulting coatings. Accordingly, we initially fabricated porous micro-nano structures on the Ti–6Al–4V alloy by micro-arc oxidation (MAO) to serve as interlocking sites. Then a CS coating was prepared via EPD, during which, an asymmetric AC pulse voltage was applied. The adverse impacts of hydrolysis were effectively avoided; thus, a flat MAO/CS coating was eventually prepared. The effect of positive bias during EPD on the surface morphology, chemical compositions, wettability, corrosion resistance, and in vitro bioactivity of the coating had been analyzed. The results indicated that the as-obtained composite coating significantly enhanced the corrosion resistance of the substrate in simulated body fluids (SBF). After immersion in SBF, the MAO/CS coating was found to induce the formation of a bone-like apatite layer on the alloy surface, indicating excellent bioactivity. When the positive bias reached 70 V, the as-prepared coating showed the best performance in all aspects. All results suggest that the modified alloy is very promising for biomedical applications.

通过电泳沉积 (EPD) 生产的壳聚糖 (CS) 涂层已被广泛应用于提高植入物的生物活性，但低涂层粘附强度和电泳过程中的水电解削弱了所得涂层。因此，我们最初通过微弧氧化（MAO）在 Ti-6Al-4V 合金上制造多孔微纳米结构作为互锁位点。然后通过EPD制备CS涂层，在此期间施加不对称的交流脉冲电压。有效避免水解的不利影响；因此，最终制备了平坦的 MAO/CS 涂层。分析了 EPD 过程中正偏压对涂层表面形态、化学成分、润湿性、耐腐蚀性和体外生物活性的影响。结果表明，所获得的复合涂层显着提高了基体在模拟体液（SBF）中的耐腐蚀性。浸入 SBF 后，发现 MAO/CS 涂层诱导合金表面形成骨状磷灰石层，表明具有优异的生物活性。当正偏压达到 70 V 时，所制备的涂层在各个方面都表现出最佳性能。所有结果表明，改性合金在生物医学应用中非常有前途。所制备的涂层在各方面均表现出最佳性能。所有结果表明，改性合金在生物医学应用中非常有前途。所制备的涂层在各方面均表现出最佳性能。所有结果表明，改性合金在生物医学应用中非常有前途。