The present invention features linear and three-dimensional supramolecular materials self-assembled from block copolymers comprising oligo(ethylene sulfide) (OES). The block copolymers assemble into fibrils, micelles, or matrices. The fibrillar materials are sensitive to oxidation, which leads to decreased OES block hydrophobicity and crystallinity, and increased water solubility of the polymer constituents. Molecular loading options, coupled with oxidative sensitivity, allow implantable or injectable fibrillar suspensions or cross-linked three-dimensional matrices to demonstrate significant biomedical potential, especially in the context of extracellular and intracellular molecular delivery and applications related to infection and disease.