A review on the construction of hydrogel scaffolds by various chemically techniques for tissue engineering

The field of tissue engineering places complex demands on the natural and synthetic biomaterials that have been applied for organ/tissue development. The materials selected to support the complicated processes of tissue development and repairs which assist to the structural and mechanical requirements of the target tissue. Hydrogels have in situ formability which permits an actual and homogeneous encapsulation of drugs/cells, and useful in vivo surgical operation in a minimally invasive way, causing less discomfort for patients. This review provides an overview on the current chemically gelling techniques, with an explanation of the state of the art on the various synthesis methods and biomedical applications of chemically gelling hydrogels, contrasting and comparing the many chemistries available for biomedical hydrogel generation using both biologic and synthetic base materials. So, we discuss about the versatile methods to design the hydrogels including click chemistry, Michael-type addition reaction and Schiff base reaction.