ABSTRACT
Hydrogels are widely utilised throughout healthcare for a variety of medical applications including for biomaterial and drug delivery purposes. This chapter explores how biomolecular hydrogels, composed of the building blocks of life (carbohydrates, lipids, proteins, and nucleic acids) can be tailored to respond to the presence of physiological stimuli. The primary emphasis of this chapter is protein-based hydrogels, composed of peptide and amino acid monomer units, due to their significant contribution to the structure of mammalian tissues and the extracellular matrix. In proteins and peptides, amino acid monomers provide functional flexibility due to their chemical versatility. Hydrogel formation, mediated by intermolecular interactions and a self-assembly process, can be triggered by changes in pH, ionic strength, oxidation/reduction, temperature, specific enzymes, presence of shear forces, light and electrical stimuli. This is advantageous as drug release and pharmacological activity can be controlled in response to such changes. This chapter will discuss each of these stimuli linking to named examples. Future perspectives are provided with regard to how these could be utilised particularly within the fields of 3D cell culture, drug delivery, regenerative medicine and tissue repair.
