State of the art and future directions of scaffold-based bone engineering from a biomaterials perspective

Abstract

Scaffold-based bone tissue engineering aims to repair/regenerate bone defects. Such a treatment concept involves seeding autologous osteogenic cells throughout a biodegradable scaffold to create a scaffold-cell hybrid that may be called a tissue-engineered construct (TEC). A variety of materials and scaffolding fabrication techniques for bone tissue engineering have been investigated over the past two decades. This review aims to discuss the advances in bone engineering from a scaffold material point of view. In the first part the reader is introduced to the basic principles of bone engineering. The important properties of the biomaterials and the scaffold design in the making of tissue engineered bone constructs are discussed in detail, with special emphasis placed on the new material developments, namely composites made of synthetic polymers and calcium phosphates. Advantages and limitations of these materials are analysed along with various architectural parameters of scaffolds important for bone tissue engineering, e.g. porosity, pore size, interconnectivity and pore-wall microstructures.

Bone tissue engineering: A review in bone biomimetics and drug delivery strategies

“…115,116 Research has shown that a synthetic bone scaffold should maintain its mechanical properties for at least 1-3 months after implantation (without shielding cells from mechanostimulation) and then should be totally resorbed through metabolic pathways after $12-18 months so that it does not impeded tissue ingrowth and regeneration. 59,117 Because of the difficulties associated with measuring the mechanical properties of bone and the synthetic scaffold during tissue regeneration and scaffold degradation in vivo, researchers have developed 3D computational modeling techniques with the goal of determining the optimal degradation rate of a synthetic scaffold. For example, assuming the scaffold degradation rate is proportional to the water penetration rate and ester bond hydrolysis (polymer degradation), and bone regeneration rate is governed by the rate equation for trabecular surface remodeling.…”

In vitro degradation of calcium phosphates: Effect of multiscale porosity, textural properties and composition

“…The need for synthetic bone grafts is clear, but their choice and design remain still complex due to many considerations such as material composition, architecture, mechanical stability, degradation products, etc. that can potentially affect the remodelling process [4].…”

Synthesis and characterisation of nanohydroxyapatite using an ultrasound assisted method

“…Hydroxyapatite (HAP) is the main inorganic calcium phosphate mineral component of bone and teeth, with a general formula of Ca 10 (OH) 2 (PO 4 ) 6 . The close chemical similarity of HAP to natural bone has led to extensive research efforts to use synthetic HAP as a bone substitute and/or replacement in therapeutic cases [3,4].…”