Microfabrication of three-dimensional engineered scaffolds.

One of the principal challenges facing the field of tissue engineering over the past 2 decades has been the requirement for large-scale engineered constructs comprising precisely organized cellular microenvironments. For vital organ assist and replacement devices, microfluidic-based systems such as the microcirculation, biliary, or renal filtration and resorption systems and other functional elements containing multiple cell types must be generated to provide for viable engineered tissues and clinical benefit. Over the last several years, microfabrication technology has emerged as a versatile and powerful approach for generating precisely engineered scaffolds for engineered tissues. Fabrication process tools such as photolithography, etching, molding, and lamination have been established for applications involving a range of biocompatible and biodegradable polymeric scaffolding materials. Computational fluid dynamic designs have been used to generate scaffold designs suitable for microvasculature and a number of organ-specific constructs; these designs have been translated into 3-dimensional scaffolding using microfabrication processes. Here a brief overview of the fundamental microfabrication technologies used for tissue engineering will be presented, along with a summary of progress in a number of applications, including the liver and kidney.