Materials for bone-tissue regeneration ceramics and polymers

4 Materials for bone-tissue regeneration ceramics and polymers 

The selection of the most appropriate material to produce a scaffold is a very important step towards the construction of a tissue-engineered product. Most of the time, the material properties will determine the properties of the scaffold itself. Up to now, several materials such as metals, ceramics and polymers from both natural and synthetic origins have been proposed. However, metals and most of the ceramics are not 

However, these materials have some major drawbacks. They are brittle and present a low mechanical stability, which prevent their use in the regeneration of large bone defects [8]. Furthermore, due to in vivo osteoclastic activity, their degradation/ dissolution rates are difficult to predict. Too-fast degradation will compromise the mechanical stability of the scaffold, which is low by itself. At the same time, a quick degradation would dramatically increase the extracellular concentrations of Ca and P, leading to cellular death [28], 

The characteristics of the main bioceramics for bone-tissue regeneration are synthetically reported in the following. In Table 15.4, their main mechanical properties and major clinical uses are collected. 

The most common types of calcium phosphate (CP) materials investigated for synthetic bone scaffolds are HA, Caio(P04)6(OH)2, a- or 3-TCP, Ca3(P04 2, biphasic calcium phosphates (BCP, consisting of HA-TCP mixtures) and multiphasic bioglasses. 

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