The Preparation And Bioactivity Of Micro/Nano Structural Titanium Loading Antimicrobial Peptide And Alginate

Due to their good mechanical properties and excellent biocompatibility, titanium and titanium alloy have been widely used as hard tissue implants. However, there are still some disadvantages such as inadequate osteogenesis inducing ability and susceptibility to bacterial infections. In this study, we use acid etching and anodization to aquire micro/nano structure on pure Ti. Then antimicrobial peptide (AMP) and sodium alginate (ALG) were loaded through layer by layer assembly. The surface morphology, composition, structure and drug release behavior were studied by various kinds of analysis methods. The effects of materials on bone tissue growth were studied by biomimetic mineraliztion and osteoblast culture. At last the antimicrobial property was tested by bacterial culture.By acid etching and anodiztion, the material surface with microporous and naotubes were fabricated. Nanotubes with 50nm diameter and 100nm diameter were prepared under 10V and 20V voltage, respectively. The X-ray diffraction result showed that the amorphous titania of the nanotubes turned into anatase crystal through 450℃ heat treatment. Tafel curve test indicated that the corrosion resistance of the materials was weakened.The X-ray photoelectron spectroscopy result showed that AMP and ALG were successfully loaded onto these materials by layer by layer assembly. And layer by layer assembly mainly relied on electrostatic force, rather than simply physical absorption. The loaded drug amount and drug release experiment showed that micro/nano structure was good for drug carrying. The nanotubes with bigger diameter can load more drugs. Drug loading efficiency can be improved by adding more layers in the same total drug amount. Besides, nanotube structure and crosslink treatment enhanced controlled release effect.The biomimetic mineralization experiment indicated that the assembled drug layers could improve HA deposition on the material surface and accelerate biomineralization.The osteoblast culture result showed that micro/nano structure was helpful for osteoblasts proliferation and differentiation. So were the drug layers. And nanotubes with bigger diameter had more significant effects.The bacterial culture showed that short-term antimicrobial property of drug-loaded samples was quite obvious while long-term antimicrobial property was weak. The antimicrobial property mostly depended on AMP release behavior of the materials.Our study indicated that it was an effective way to combine surface micro/nano morphology modification and antimicrobial drug loading. It could both benefit materials’ biocompatibility with bone tissue and antimicrobial property against infection.