We report on the synthesis of 700 nm thick bioglass thin films by magnetron sputtering from 45S5 bioglass targets in the argon atmosphere. The adhesion of films to Ti substrates increased 1 75 times when introducing an similar to 70 nm thick mixed glass-Ti buffer layer (BG(1-x)Ti(x) (x = 0-1)) with gradient of composition by co-sputtering. The morphological and structural properties of the films were studied by XRD, ETIR and microscopic techniques, showing an improvement after the two-hour thermal air treatment at 650 degrees C. We investigated in vitro the viability and proliferation of human osteoblast cells cultivated onto the surface of the films The osteoblasts spread over the surface adopting typical polyhedral shapes with numerous focal adhesion points and protrusions infiltrating deep into the films. We assigned this evolution to the improved mechanical properties and enhanced bioactivity due to the prevalent formation of combeite and wollastonite crystalline phases in the heat treated bioglass films (C) 2010 Elsevier B.V All rights reserved