Monday, November 5, 2007 - 3:55 PM

Nanostructured Titania/plga Composite Scaffolds Improve Cytocompatibility and Mechanical Strength for Better Bone Regeneration

Huinan Liu, Division of Engineering, Brown University, 182 Hope street, Box D, Providence, RI 02912 and Thomas J. Webster, Division of Engineering&Division of Orthopedics, Brown University, 182 Hope Street, Box D, Providence, RI 02912.

The design of synthetic scaffolds is crucial for replacing functions to diseased or injured bones. The desired scaffolds should be able to rapidly induce new bone formation, should possess initial sufficient mechanical strength for load-bearing applications before new bone has been regenerated, and should maintain their mechanical integrity until new bone formation has occurred. In this study, a bio-inspired ceramic/polymer nanocomposite was developed to serve as a mirror template for new bone growth. Specifically, nano-sized titania particles were dispersed in a model polymer (PLGA or poly-lactide-co-glycolide) matrix using controlled sonication. Results of this study showed that the nano-titania/PLGA composites provided better biological and mechanical properties. For example, in vitro studies provided evidence of increased osteoblast (bone-forming cell) adhesion and calcium-containing mineral deposition on well-dispersed nano-titania in PLGA composites compared to pure PLGA scaffolds and the more agglomerated nano-titania in PLGA scaffolds. Moreover, well-dispersed nano-titania in PLGA increased the compressive modulus of scaffolds compared to pure PLGA scaffolds and the more agglomerated nano-titania in PLGA scaffolds. The addition of titania nanoparticles in PLGA also decreased the weight loss of scaffolds, reduced harmful acidic pH changes during PLGA degradation, and prolonged mechanical integrity of such scaffolds. In summary, the combination of PLGA with a strong and biocompatible well-dispersed nano-titania phase created better materials for bone regeneration.