Novel thermo- and pH-responsive hydroxypropyl cellulose- and poly (l-glutamic acid)-based microgels for oral insulin controlled release

► In this article we synthesized a series of thermo- and pH-responsive microgel particles. ► The particles may undergo reversible volume phase transitions in response to both pH and temperature changes. ► In vitro the amount of insulin released from microgels is much less at pH 1.2 than that at pH 6.8.