Biomimetic Hydrogels for Regenerative Medicine

Assembled from either natural and/or synthetic polymers, hydrogels are one of the most versatile structures in biomedicine. They are made up of hydrophilic polymer chains forming a three-dimensional network that can absorb hundreds if not thousands of times their dry weight in water and can be cast into almost any desired form, shape, and size. The interaction between water and polymer defines their structural and physical properties and gives these materials practical advantages in numerous biomedical applications. For example, hydrogels have been used as medical implants, such as contact lenses or cosmetic dermal fillers, because they provide a means of precisely controlling the interface with living cells, tissues, and endogenous macromolecules in that environment. Biomimetic hydrogel features that can be engineered at the macroscale and microscale, including compositional and physical properties, are practical for guiding cellular fate, whereas nanoscale features are used for mediating interactions specific with endogenous proteins, lipids, carbohydrates, nutrients, and soluble gasses. Hydrogels are engineered with tissue-like compatibility by leveraging on the polymeric network and its relationship with waterborne molecules that surround it - a concept derived from natural tissue structure-function. Biomedical hydrogels can thus be applied to a very broad spectrum of research and clinical functions, ranging from surgical adhesives to materials for cell and tissue culture. This chapter explores the fundamental aspects of designing biomimetic, cell-responsive hydrogels for some of these biomedical applications.