Mussel-inspired controllable drug release hydrogel for transdermal drug delivery: Hydrogen bond and ion-dipole interactions

Hydrogels have broad application prospects in drug delivery due to their biocompatibility, high water content and three-dimensional structure. However, the regulation of drug release from hydrogels is an important issue in medical applications. At the same time, water also has an important impact on drug release. In this study, a hydrogel with hydrogen bond and ion dipole interaction (PAHDP) was prepared by introducing catechol group into polymer to regulate drug release. Ten model drugs were selected to explore the relationship and mechanism of action among polymer, drug and water. The results showed that PAHDP had excellent adhesion and safety. Drug release test showed that 10 kinds of drugs had different drug release trends, and the release amount was negatively correlated with drug polarizability and LogP. In addition, in vitro transdermal test and pharmacokinetic results showed that the hydrogel based on PAHDP achieved increased or decreased blood drug concentration, and the area under the concentration-time curve (AUC) of >1.5 times showed its potential to regulate drug release. The mechanism study showed that the hydrogen bond and ion dipole interaction between polymer and drug were affected by drug polarizability and LogP, and the distribution of water in different states was changed. Hydrogen bond and ion dipole interactions synergistically control drug release. Therefore, the mussel inspired PAHDP hydrogel has the potential to become a controllable drug delivery system.