Gallium-doped titania nanotubes elicit anti-bacterial efficacy in vivo against Escherichia coli and Staphylococcus aureus biofilm

In this work, the modification of titanium surface with TiO2 nano-tubes (TNTs), and a solvent casting of biocompatible polymer (poly-DL-lactic acid) film combines gallium (III), as a factor of anti-inflammatory and bone resorption inhibitors, was assessed in the spinal infection rat model. Under in vitro condition, it is found that S. aureus and E. coli can attach and competitively survive on the TiO2 nano-tube surface and form the mixed bacteria biofilm. By contrasting the in vivo implantation of Cp Ti, TNTs and Ga-Cp Ti scaffolds, Ga-doped TNTs showed distinct and excellent anti-bacterial property and reduced inflammation and favorable compatibility with osteoblasts, which reveal a large potential of exploiting and modifying the multi-biofunction of implantable biomaterials. The described in vivo work expands the fundamental understanding of the advantages of gallium (III) and titania nano-array on antiresorptive and antimicrobial properties and the designing strategy of the composite coating is broadly applicable to a wide range of multifunctional biomaterials.