The Design of Scaffolds for Use in Tissue Engineering. Part II. Rapid Prototyping Techniques

Abstract

Tissue engineering (TE) is an important emerging area in biomedical engineering for creating biological alternatives for harvested tissues, implants, and prostheses. In TE, a highly porous artificial extracellular matrix or scaffold is required to accommodate mammalian cells and guide their growth and tissue regeneration in three-dimension (3D). However, existing 3D scaffolds for TE proved less than ideal for actual applications because they lack mechanical strength, interconnected channels, and controlled porosity or pores distribution. In this paper, the authors review the application and advancement of rapid prototyping (RP) techniques in the design and creation of synthetic scaffolds for use in TE. We also review the advantages and benefits, and limitations and shortcomings of current RP techniques as well as the future direction of RP development in TE scaffold fabrication.

Biomimetic materials for tissue engineering

“…To tackle this problem, computer-assisted-design and computerassisted-manufacture (CAD/CAM) techniques, a.k.a. solid freeform fabrication (SFF) or rapid prototyping, that have been widely used in modern manufacture industry, are adopted by the field of tissue engineering [3,[95][96][97][98]. However, the existing SFF techniques also have their limitations such as limited material selections, inadequate resolution, and structural heterogeneity due to the "pixel assembly" nature of these fabrication processes [2].…”

Scaffolding in tissue engineering: general approaches and tissue-specific considerations

“…Over the last decade, development of fabrication technologies for porous scaffolds has been an intensive area of research. Readers are also directed to several excellent review articles for various fabrication technologies [25,34,50,54,107,109,124,125]. In general, these technologies can be classified into (1) processes using porogens in biomaterials, (2) solid free-form or rapid prototyping technologies and (3) techniques using woven or non-woven fibers.…”

“…Porogens are removed after fabrication using methods such as sublimation, evaporation and melting to leave behind a porous structure in the scaffold. Example techniques include solvent casting and particulate leaching, gas foaming, freezedrying and phase separation [124]. In the second category, hierarchical porous structures are manufactured by sequential delivery of material and/or energy needed to bond the materials to preset points in space [50].…”

Porous magnesium-based scaffolds for tissue engineering

“…Present tissue engineering approaches are focused on the development of porous scaffolds made of different biomaterials with the aim of replacing and restoring the pathologically altered tissues by transplantation of the cells [9,10]. Such scaffolds for engineering of hard tissues need suitable mechanical integrity [11].…”