Novel biomimetic sandwich-structured electrospun cardiac patches with moderate adhesiveness and excellent electrical conductivity

Clinical cardiac patches exhibit unsatisfied biocompatibility, low adhesion, and inadequate compliance and
suboptimal mechanical properties for cardiac disorders repair. To address these challenges, herein we have
innovatively proposed a biomimetic nanofiber electrospun membrane with a sandwich structure strategy. The
composite patch comprises a stretchable polyurethane (PU) as basic material, then infiltrated with biocompatible
silk fibroin methacryloyl (Silk-MA) as the middle layer via electrospinning and finally covered with Bio-ILs
(chemically modified biocompatible ionic liquids) to impart electrical conductivity. Results indicated that the
incorporation of Bio-ILs significantly enhances the conductivity reaching 2877 mS/m; particularly due to the
positive charges of Bio-ILs, the composite film exhibits mild adhesive properties, inducing minimal damage to the
substrate tissue. Furthermore, the basic PU of bilayer nanofiber membrane increased the film’s stretching strain
to approximately 250%, the Silk-MA hydrogel coating changed the film from hydrophobic to hydrophilic,
creating a favorable and biocompatible microenvironment. Finally, in vitro experiments on cardiomyocytes
confirmed that the material exhibits low cytotoxicity and excellent biocompatibility. Overall, the biomimetic
sandwich electrospun membrane could restore electrical conduction and synchronized contraction function,
providing a promising strategy for the treatment of cardiac tissue engineering.