Construction of Zn-incorporated multilayer films to promote osteoblasts growth and reduce bacterial adhesion

To improve the biological performance of titanium substrates, a bioactive multilayered structure of chitosan/gelatin pair, containing zinc ions, was constructed via a layer-by-layer self-assembly technique. The successful preparation of zinc ions incorporated multilayer films was demonstrated by scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle measurements, respectively. The biological behaviors of osteoblasts adhered to modified Ti substrates were investigated in vitro via cytoskeleton observation, cell viability measurement, and alkaline phosphatase activity assay. The cytocompatibility evaluation verified that the present system was capable of promoting the growth of osteoblasts. In addition, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria were used to evaluate antibacterial property of modified Ti substrates. Bacterial adhesion and viability assay confirmed that Zn-loaded multilayer films were able to inhibit the adhesion and growth of bacteria. The approach presented here affords an alternative to reduce bacterial infection and promote osteoblast growth for titanium-based implants.