Self-healing polyurethane elastomers based on charge-transfer interactions for biomedical applications

One promising application of self-healing polymeric materials is biomedical use. Although charge-transfer (CT) interactions have been employed to construct self-healing polymers as well as other reversible bonds and interactions, their potential for biomedical applications has never been investigated. In this study, we fabricated self-healable and cell-compatible polyurethane elastomers cross-linked by CT complexes between electron-rich pyrene (Py) and electron-deficient naphthalene diimide (NDI) by simply blending two linear polymers with Py or NDI as a repeating unit. The elastomers with different blend ratios self-healed damage over 1 day in mild conditions, including in air and water at 30-100 degrees C. The mechanical properties of damaged elastomers were almost restored after healing in air at 100 degrees C, and even in air at 30 degrees C and in water at 70 degrees C, healing was also possible to a certain extent. The good cell compatibility of the polyurethane elastomers was demonstrated by culturing two kinds of cells on the thin film substrates.