Fabricationof Supramolecular Polymers Based On The Interaction Between Tripeptide Of FGG And Curcubit [8] Uril

Supramolecular polymers are polymers fabricated by monomers through noncovalent interactions. The dynamic nature of noncovalent interactions givessupramolecular polymers some new properties that do not exist in most conventional covalent polymers, such asrecyclability, stimuli-responsivity, processibility, and even self-healing property.Because of these unique properties, supramolecular polymers draw more and more attentionand many people start to work on thisfield. Although this field has progressed rapidly, it is stillhighly desirable to find new driving forces for supramolecular polymerization, and to fabricatefunctional supramolecular polymers.Selenium-containing polymers are a type of promising biomedical materials with redox responsiveness. In recent years, this field is developing rapidly, and it is very important to develop new type of selenium-containing polymers to enrich the class of biomedical materials.In this work, we prepared supramolecular polymers throughthe specific interaction between tripeptide of FGG and cucurbit[8]uril(CB[8]), and fabricatedselenium-containing supramolecular polymers for the first time, including the following two parts:1. We prepared water-soluble supramolecular polymers through the specific interaction between tripeptide of FGG and CB[8]. To promote supramolecular polymerization, the following points were take n into consideration:(1) a long spacer is helpful for avoiding cyclization(2) a water-soluble linker can increase the solubility of monomers in water.To this end, we designed and synthesized a bifunctional monomer bearing a water-soluble linker ofoctaethylene glycol between two FGG residues. By equimolarly mixingthe bifunctional monomer and CB[8]in aqueous solution, we fabricated supramolecular polymers, and developed a new driving force for supramolecular polymerization.2. We fabricatedthe selenium-containing supramolecular polymers for the first time through the specific interaction between tripeptide of FGG and CB[8]. The amphiphilic diselenide-containing supramolecular polymers can further aggregate, and the small molecule Nile Red can be loaded in the formed aggregation.Under a low concentration of hydrogen peroxide as an oxidant or tris(2-carboxyethyl)phosphine as a reductant, the aggregation can be destroyed with the break of the deselelide bond. By this way, the redox-stimuli controlled release can be realized.Our research demonstrates that the bifunctional monomer with a long soft spacer can facilitate the formationof supramolecular polymers. Considering the biocompatible nature of the building blocks,we expect that this method of supramolecular polymerizationcan be further applied in fabricating environmentally friendlyand biocompatible supramolecular polymeric materials. Moreover, the construction of selenium-containing supramolecular polymers not only expands the library of selenium-containing polymers, but also offers a new strategy to develop functional supramolecular polymers.