Preparation of Three-Dimensional Graphene Oxide Electric-Field/Temperature-Sensitive Hydrogels and Transdermal-Controlled Release Drug Delivery Study

The environmental responsiveness of smart responsive gels under specific conditions has attracted great attention in recent years. In this paper, we have investigated the preparation of previously unreported electric field/temperature-sensitive three-dimensional graphene oxide hydrogels and their transdermal absorption studies, choosing indapamide (IND) as a model drug. Three-dimensional graphene oxide (3D@GO) has a unique three-dimensional network-like structure, excellent electrical properties, and mechanical properties. Three-dimensional graphene oxide network structures were prepared based on graphene oxide (GO) with the addition of formaldehyde, resorcinol, and sodium carbonate as reactants and catalysts. 3D@GO was compounded with a temperature-sensitive gel matrix, hydroxybutyl chitosan (HBC), to obtain a temperature-sensitive composite hydrogel with enhanced mechanical, electrical, and thermal properties. After applying 3D@GO–HBC to the skin, it can rapidly convert from liquid to semi-solid and adhere to the skin at the skin temperature. It can also be used as a carrier for controlled drug release under electric field conditions. This study of transdermal-controlled release drug delivery under electric field modulation showed that the cumulative release values of IND were 2.02 μg/cm2, 2.21 μg/cm2, 2.45 μg/cm2, 2.85 μg/cm2 , and 3.16 μg/cm2 in 24 h under the application of electric fields of 0 μA, 50 μA, 100 μA, 150 μA and 200 μA, respectively. The results indicated that 3D@GO–HBC hydrogels have good electrical sensitivity and can enhance the cumulative transdermal release of drugs under electric field conditions, providing an advantage not previously reported for controlled release of drugs.