Sina Farzaneh - Department of Tissue Engineering and Regenerative Medicine, School of Advanced Technology in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Reza Samanipour - Department of Tissue Engineering and Regenerative Medicine, School of Advanced Technology in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Designing of biologically active scaffolds with optimal characteristics is one of the key factors for successful tissue engineering. Recently, hydrogels have received a considerable interest as leading candidates for engineered tissue scaffolds due to their unique compositional and structural similarities to the natural extracellular matrix, in addition to their desirable framework for cellular proliferation andsurvival. More recently, the ability to control the shape, porosity, surface morphology, and size of hydrogel scaffolds has created new opportunities to overcome various challenges in tissue engineering such as vascularization, tissue architecture and simultaneous seeding of multiple cells. This review provides an overview of the different types of hydrogels, the approaches that can be used tofabricate hydrogel matrices with specific features and the recent applications of hydrogels in tissue engineering. Special attention was given to the various design considerations for an efficient hydrogel scaffold in tissue engineering. Also, the challenges associated with the use of hydrogel scaffolds were described. In this review, an attempt was made, from the materials science point of view, to provide an overviewof the different classes of hydrogels, the available approaches for fabricating hydrogel scaffolds with specific features, and the recent discoveries and applications of hydrogels in tissue engineering. Special attention was also given to the various design criteria toward an efficient hydrogel scaffold. The challenges associated with the use of hydrogel scaffolds were also described.

Hydrogels, Scaffolds, Biodegradability, Biocompatibility, Tissue engineering