From Mesenchymal Cell News:
Researchers report a new approach to controlled drug release based upon exploiting the dynamic equilibrium that exists between Diels-Alder reactants and products, demonstrating the release of a furan containing dexamethasone peptide from a maleimide containing hydrogel. Using a reaction-diffusion model, the release kinetics were tuned to achieve sustained concentrations conducive to osteogenic differentiation of human mesenchymal stem cells.
http://connexoncreative.com/publications/archives/MSC509.aspx