Abstract
Tissue Engineering (TE) has emerged to help regenerate tissue/organ by engineering biological substitutes for the damaged tissues/organs. One of the methods in TE is to create TE scaffold as a temporary Extra Cellular Matrix (ECM) for growing cells in order to regenerate new tissues. The complex requirements from different cell types in terms of scaffold structure and material should be fulfilled in order to mimic the native ECM. Due to this reason, the control over the scaffold microstructure becomes an important issue in fabricating TE scaffolds. However, conventional scaffold fabrication techniques lack the ability to control the scaffold microstructure. Therefore, Rapid Prototyping (RP) techniques are deemed suitable for TE applications. In the case of regenerating tissues with structural gradients or multiple tissues with tissues interfaces, designing TE scaffolds can be difficult as one scaffold may have structural gradients to cater for the different requirement of each tissue/cell type. Researches have sought to create computer-aided systems to help design scaffolds with such complex structures. This paper reviews some RP techniques that have been able to fabricate TE scaffolds with structural gradients. TE with computer-aided systems will also be included and the challenges in creating functionally graded scaffolds will be discussed.