Recent studies confirm that the phenotypes with "classically activated" M1 macrophages and "alternatively activated" M2 macrophages play a key role in regulating immune their polarization into pro-inflammatory M1 and anti-inflammatory M2 macrophages. M1 macrophages initiate angiogenesis in early stage. However, the predominance of M1 macrophages for a long time would lead to a chronic inflammatory disease. We reasoned that biomedical implants had the potential to shift M1 macrophages to M2 macrophages at desirable time point would result in tissue repair and wound healing effectively. In this study, double-layer sol–gel coatings on TiO2 nanotubes (TNTs) were fabricated for cytokine IL-4 controllable release in desired time period in order to mediate M1 macrophages switching to the M2 phenotype. The first layer of sol-gel formed on TNTs was carboxymethyl chitosan (CMCS) hydrogel using CMCS as the biopolymer and EDC/NHS as the crosslinker for cytokine IL-4loading, denoted as IL4/TNTs. The second layer fabricated on IL4/TNTs sample was another type of CMCS hydrogel using genipin as the crosslinker, which is designed for the encapsulation of inner layer to realize IL-4 controllable release at desired time point. The resulted sample was n medGH/IL4/TNTs. Samples were characterized by scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The toxicity of the sample was examined using Alamar Blue test and live/dead cell staining with two types of cells osteoblast and macrophages. We analyzed the in vitro kinetics of macrophage phenotype switch using gene expression, flow cytometry, and cytokine secretion analysis. The results showed that the double-layer sol–gel coatings were fabricated on TNTs and the second layer covered on the first layer to realize IL-4 controllable release. In vitro release study demonstrated IL-4 was released from sample after 48 h and followed with a prolonged period. These samples promoted M2 polarization of macrophages as measured by gene expression of M1 and M2 markers and the secretion of the cytokines. Thus, the strategy described here provides a new approach to utilizing biomaterials for directing the polarization of macrophages. phenotype switch using gene expression, flow cytometry, and cytokine secretion analysis. The results showed that the double-layer sol–gel coatings were fabricated on TNTs and the second layer covered on the first layer to realize IL-4 controllable release. In vitro release study demonstrated IL-4 was released from sample after 48 h and followed with a prolonged period. These samples promoted M2 polarization of macrophages as measured by gene expression of M1 and M2 markers and the secretion of the cytokines. Thus, the strategy described here provides a new approach to utilizing biomaterials for directing the polarization of macrophages.