Bone tissue engineering: state of the union

• Clinically inspired performance criteria for designing holistic tissue regenerative therapeutics.
• Recent advances in the design of therapeutics using stem cells, growth factors, and scaffolds.
• Major obstacles to successful tissue regeneration in the clinic and potential solutions to them.
• The potential roles of emerging technologies in future bone tissue engineered products.

The quest to surpass the clinical efficacy of the allogeneic bone graft has had limited success, an outcome that is symbolic of tissue engineering as a whole. In this ‘State of the Union’-type review, we highlight recent advances in the design of bone regenerative therapeutics using the primary elements of stem cells, growth factors and scaffolds, and identify major obstacles in their paths to the clinic. We underscore the need for rigorous performance criteria in the design of holistic tissue regenerative therapeutics, and an increased emphasis on the product production, storage and handling issues that will ultimately influence clinical success.