Editorial: Smart Hydrogels in Tissue Engineering and Regenerative Medicine

Tissue engineering, consisting of scaffolds, cells, favorable growth factors, and biomechanical stimulation, has been a most promising therapeutic strategy for tissue reconstruction and regenerative medicine. In general, an ideal tissue-engineered scaffold should be porous, non-toxic, with a matched biodegradable rate, high mechanics, and diffused nutrients and metabolite properties, which can effectively benefit the cell growth, proliferation, and migration, as well as the tissue vascularization process to promote tissue generation. Hydrogels, occurring abundantly with characteristics such as high-water absorption, biodegradation, adjustable porosity, and biocompatibility like that of the natural extracellular matrix (ECM), have been recognized as one of the most suitable scaffold biomaterials for tissue engineering and regenerative medicine. In addition, these scaffold-oriented hydrogels can also be utilized as idea carriers for embedding living cells, transporting tissue cells and growth factors, controlling degradation profiles and releasing stimulatory growth into the specific tissues at different time scales. Due to this, many researchers have been greatly interested in hydrogels with hierarchical structures to mimic the complex interaction of cells with their microenvironment at multiple length scales.