Synthesis and Characterization of Novel pH-Responsive Aminated Alginate Derivatives Hydrogels for Tissue Engineering and Drug Delivery.

DAP-g-SA and DAH-g-SA pH-sensitive hydrogels were successfully synthesized through amide bond linkages. The new synthesis derivatives showed lower swelling levels at low pH (4.4). In contrast, their swelling levels at higher pH (7.4) were significantly enhanced. Higher swelling degree could be obtained at high pH. pH-responsive hydrogels are especially useful for various biological applications due to their unique feature of controlled swelling, biodegradability, biocompatibility, and fluid retention in their network structures. pH-responsive hydrogels, as intelligent systems, can be used in controlled-release drug delivery systems such as insulin delivery.