pH-responsive hydrogels: synthesis and physicochemical properties

Here, the synthetic aspecs and physical chemistry of pH sensitive hydrogels as well as some of their applications in the biomedical field are revised. pH-sensitive hydrogels respond to changes in pH by swelling or collapsing and can be classified as cationic and anionic. Cationic are hydrogels display amine groups and capable of protonating at low pH while anionic hydrogels usually display carboxylate groups and charge at basic pHs. Changes in the swelling of hydrogels pH induce the opening or closing of pores in the hydrogel. pH is a stimulus which is easy to control and has biological relevance. pH-sensitive hydrogels have multiple applications in drug delivery for encapsulation and delivery of drugs and for tissue engineering.