Introducing Students to the Medical Applications of Cross-Linked Hydrogels Using Nontoxic Materials and Experiments Suitable for Many Settings

摘要

We report a series of three experiments that introduce students at different stages of their academic preparation to the medical applications of hydrogels for controlled drug delivery and wound healing. The laboratory activity bridges the fundamental concepts of chemistry (acids and bases, equilibria, solvation, and reversible esterification) with the chemistry of polymers and cross-linking, which are among the main tools of nanotechnology. The activity is customizable for students ranging from middle school to undergraduate college academic backgrounds. The two simple experiments demonstrate acid- or glucose-triggered release of a dye (model drug) from cross-linked poly(vinyl alcohol)-based gels. This mimics controlled drug delivery to more acidic cancer cells and controlled release of insulin from antidiabetic patches. The third, more technically challenging experiment demonstrates irreversible solidification of a phosphate-cross-linked chitosan gel upon heating from room temperature to body temperature. This experiment demonstrates wound healing materials that seal the wound with a nontoxic biocompatible gel. All experiments involve only nontoxic materials and can be performed under any settings.