The book provides an overview of the development and applications of clinically relevant hydrogels, used particularly in tissue engineering, regenerative medicine, and drug delivery. It approaches the topic from chemistry, materials science, biology, medicine, nanotechnology, and bioengineering points of view. The book first reviews proteins and polysaccharides that mimic extracellular matrix. This is followed by the discussion of generation and applications of supramolecular hydrogels. The final part of the book covers design and functions of cell encapsulation systems.