Polyanionic self-healing hydrogels for the controlled release of cisplatin

The development of multifunctional self-healing hydrogels is limited by the lack of simple methods to prepare multifunctional polymers. In this work, a multifunctional polymer containing phenylboronic acid (PBA) and phosphonic acid (PA) groups was prepared via a one-step Kabachnik-Fields (KF) reaction and free radical polymerization followed by an effective hydrolysis reaction. The negatively-charged polymer can react with poly (vinyl alcohol) to generate a polyanionic self-healing hydrogel under mild conditions (25 degrees C, pH = 7.4) via dynamic borate ester bonds. The hydrogel has a low cytotoxicity and can be used for 3D cell culture. The negative charged PA groups in this hydrogel efficiently bind positively-charged cisplatin, resulting in a significant improvement of its safety. The polyanionic self-healing hydrogel demonstrates a new application of the KF reaction in interdisciplinary areas that will prompt broader studies on multicomponent reactions in polymer chemistry and material science.