(734c) Block Copolymer Organogels As Potential Payload Delivery Media

Block copolymer gels, specifically those containing hydrocarbon solvents (i.e., organogels) have been recognized for a number of decades due to their tunable mechanical behavior and thermally reversible sol-gel transitions. These attributes make them amenable for applications such as gel cushioning in consumer goods and as hydrophobic filler in transoceanic fiber optic cables. Concurrently, physically and covalently crosslinked hydrogels have been investigated as drug delivery media due to their ability to encapsulate and controllably release therapeutic compounds. While organogels have been designed for drug delivery, existing technologies are heavily focused on low-molecular-weight and homopolymer gelators. The present work initiates consideration of block copolymer organogels as media capable of retaining and delivering compounds – both hydrophobic (as dispersed molecules) and hydrophilic/amphiphilic (as encapsulants within reverse micelles). First, a structural description of block copolymer organogels (unloaded and loaded) will be provided in the context of delivery media. Particular emphasis will be placed upon the precise tunability of nanoscale features through molecular and formulation design, which are experimentally captured via small angle x-ray scattering (SAXS). Next, cargo release kinetics will be discussed with a focus on the role of nanoscale structure.