Development of Composite Scaffolds for Load-Bearing Segmental Bone Defects

Table 3

Bone tissue-engineered scaffold requirements.

Biological properties	Osteogenicity: ability of a bone scaffold to allow bone cells to induce differentiation from uncommitted mesenchymal cells to preosteoblast lineage and to secrete and mineralize extracellular matrix.
	Osteoconductivity: quality of a bone scaffold having a surface that is bioactive and promotes cell attachment and migration, as well as penetration within the construct.
	Osteoinductivity: ability of a bone scaffold to not only support but also to initiate bone growth through growth factor or hormone release.
	Biocompatibility: ability of a bone scaffold to not cause an immune reaction or rejection when interacting with the body.
	Promotes vasculogenesis: ability of a bone scaffold to promote and/or easily allow for vasculogenesis to occur within the construct.
Material properties	Mechanical Stability: quality of a bone scaffold to have an ultimate compression strength that is similar to bone, while maintaining the appropriate architecture.
	Biodegradability: the quality of a bone scaffold to degrade naturally without creating toxic byproducts while being resorbed. The rate of degradation should match the rate of new bone formation, to avoid possible gaps in regeneration.
	Architecture: the quality of a bone scaffold to have a very open porous structure that is interconnected throughout the construct. This allows for greater attachment surface area, higher cell density, and easier nutrient/growth factor flow within the construct.
	Pore size/porosity: quality of a bone scaffold to have pore size and porosity percent similar to established guidelines. Ideal pore size ranges from 300 to 900 um in diameter, whereas overall porosity ranges from 60 to 99%.