Synthesis and characterization of pH- and temperature-sensitive materials based on alginate and poly(N-isopropylacrylamide/acrylic acid) for drug delivery

The significant developments in the field of polymer have advanced the synthesis of polymer-based materials and have expanded their use in a wide variety of applications. Today, polymers can be designed to change their properties in response to a single stimulus or multiple stimuli. Such types of polymers are called stimuli-sensitive or stimuli-responsive polymers, and have been utilized for controlled release in the field of biomedicine. Herein, we report the use of alginate (SA) based graft copolymer with poly(N-isopropylacrylamide) (PIPAAm) and poly(acrylic acid) (PAA) to synthesize dual stimuli-sensitive beads via microwave-assisted graft copolymerization method for controlled release of indomethacin (IND). It is demonstrated that the polymer beads composed of SA-g-PIPAAm/PAA are sensitive to pH and temperature. The structure of successfully prepared stimuli-sensitive beads by cross-linking via glutaraldehyde is characterized by FTIR, X-RD and SEM analysis.