H-Bonding Supramolecular Hydrogels with Promising Mechanical Strength and Shape Memory Properties for Postoperative Antiadhesion Application

Development of a physical barrier with mechanical properties similar to human smooth muscle and an on-demand degradation profile is crucial for the clinical prevention of postoperative adhesion. Herein, a series of supramolecular hydrogels (PMI hydrogels) composed of poly(ethylene glycol) (PEG), methylenediphenyl 4, 4-diisocyanate (MDI), and imidazolidinyl urea (IU, hydrogen bonding reinforced factor) with biodegradability and high toughness are reported to serve as physical barriers for abdominal adhesion prevention. The tensile fracture strength and strain of the PMI hydrogels could be adjusted in the ranges of 0.6-2.3 MPa and 100-440%, respectively, and their Young's moduli (0.2-1.6 MPa) are close to that of human soft tissues like smooth muscle and skin tissue as well as they have outstanding shape memory properties. The PMI hydrogels show good cell and tissue biocompatibility, and the in vivo retention time is in accord with the needs for the postoperative antiadhesion physical barriers. Through an abdominal defect model on mice, this study shows that the PMI hydrogel can completely prevent tissue adhesion compared to the commercialized Seprafilm with high safety. Owing to the promising mechanical properties and good biocompatibility, the PMI hydrogels may be extended for various biomedical applications and the development of advanced flexible electronic devices.