Design of Advanced Polymeric Hydrogels for Tissue Regenerative Medicine: Oxygen-Controllable Hydrogel Materials.

Engineered polymeric hydrogels have been extensively utilized in tissue engineering and regenerative medicine because of their biocompatibility, tunable properties, and structural similarity in their native extracellular microenvironment. The native extracellular matrix (ECM) has been implicated as a crucial factor in the regulation of cellular behaviors and their fate. The emerging trend in the design of hydrogels involves the development of advanced materials to precisely recapitulate the native ECM or to stimulate the surrounding tissues via physical, chemical, or biological stimuli. The ECM presents various parameters such as ECM components, soluble factors, cell-to-cell and cell-to-matrix interactions, physical forces, and physicochemical environments. Among these environmental factors, oxygen is considered as an essential signaling molecule. In particular, abnormal oxygen tension such as a lack of oxygen (defined as hypoxia) and an excess supply of oxygen (defined as hyperoxia) plays a pivotal role during early vascular development, tissue regeneration and repair, and tumor progression and metastasis. In this chapter, we discuss how engineered polymeric hydrogels serve as either an artificial extracellular microenvironment to create engineered tissues or as an acellular matrix to stimulate the native tissues for a wide range of biomedical applications including tissue engineering and regenerative medicine, wound healing, and engineered disease models. Specifically, we focus on emerging technologies to create advanced polymeric hydrogel materials that accurately mimic or stimulate the native ECM.