TiO₂ foams with poly-(d,l-lactic acid) (PDLLA) and PDLLA/Bioglass^® coatings for bone tissue engineering scaffolds

TiO₂ foam-like scaffolds with pore size ~300 μm and >95% porosity were fabricated by the foam replication method. A new approach to improve the structural integrity of the as-sintered foams, which exhibit extremely low compression strength, was explored by coating them with poly-(d,l-lactic acid) (PDLLA) or PDLLA/Bioglass^® layers. The PDLLA coating was shown to improve the mechanical properties of the scaffold: the compressive strength was increased by a factor of ~7. The composite coating involving Bioglass^® particles was shown to impart the rutile TiO₂ scaffold with the necessary bioactivity for the intended applications in bone tissue engineering. A dense hydroxyapatite layer formed on the surface of the foams upon immersion in simulated body fluid for 1 week.