Introduction :

Additive manufacturing (AM), the process of joining materials to make objects from 3D CAD model data, such as 3D printing, is showing a high potential to radically disrupt the global consumer market and trigger a manufacturing revolution in a broad spectrum of applications in many industry sectors. 3D printing is mostly well-known for custom-fabrication of industrial prototypes and parts using standard fabrication materials such as plastics and metals has recently infiltrated into many industries such as aviation, automobile, dental, electronic and fashion. The successful implementation of AM in the healthcare industry has resulted in the development of surgical equipment, prosthetics, medical devices, and implants. More recently, 3D printing has been adopted to utilize life cells and gels as printing materials (bioinks) to create ex vivo and in vitro tissue models. Such technology heralds new frontiers in medicine.

In vitro, cells cannot arrange themselves in three-dimensional (3D) structure similar to that in real tissue in vivo. Various tissue engineering techniques were developed, aiming to develop tools that are able to mimic the living tissue structure and function. Biofabrication is an innovative technique that evolved from various fabrication technologies, particularly 3D printing and bioreactor, opening the door for new technology (AM-based tissue engineering). 3D printing is the process of integration of living cells with biomaterials that allows controlled deposition of cells/bioink with maintained cellular viability in 3-dimensional space to create complex multifaceted tissues.