Preparation of novel β-CD/P(AA-co-AM) hydrogels by frontal polymerization

In this paper, betaine (Bet) was used as a hydrogen bond acceptor (HBA), acrylic acid (AA) and acrylamide (AM) were used as hydrogen bond donors (HBD) and mixed to form a deep eutectic solvent (DES). Different concentrations of β-cyclodextrin (β-CD) were dispersed in DES, and a novel β-CD/P(AA-Co-AM) hydrogel was prepared by frontal polymerization (FP). Characteristic structure and morphology of the hydrogels were analyzed using Fourier infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), and the properties of the hydrogels were investigated. The results show that the mechanical properties of the hydrogel were improved by β-CD acting as a second cross-linking agent in the polymerization process, thus increasing the cross-link density of the hydrogel. Because the carboxyl groups contained in acrylic acid dissociate under alkaline conditions, the composite hydrogel shows excellent pH responsiveness under alkaline conditions. Tetracycline hydrochloride was used as a drug model to test the drug loading and drug release performance of hydrogels. With the increase of β-CD content, the loading capacity of hydrogels to tetracycline hydrochloride gradually increased. The data of drug release indicated that the hydrogel has good drug delivery performance and has promising applications in drug delivery systems and other areas.