Table 1.

Criteria of an ideal scaffold for bone tissue engineering (Bruder and Caplan 2000; Chen et al. 2008; Liu et al. 2013)

Criteria	Requirement
Biocompatibility	Support and foster cells’ attachment, proliferation and differentiation, and initiate tissue regeneration both in vitro and in vivo
Osteoconductivity	Encourage host bone adherence and growth into the scaffold
Biodegradability	Be able to degrade at a physiologically relevant rate
Mechanical properties	Maintain proper mechanical stability for tissue regeneration
Porous structure	Be highly porous (>90 %) and interconnected, with pore diameters between 300 and 500 μm, to allow cells to penetrate into a pore structure, and promote new bone formation, as well as vascularisation. It must be able to deliver nutrients into the scaffold and transport undesirable metabolites outside scaffold
Fabrication	Possess desired fabrication capabilities (e.g. being readily produced into irregular shapes of scaffolds that match the defects in the bone of individual patients)
Commercialisation	Be fabricated at an acceptable cost for commercialisation