Development of an Asymmetric Hydrophobic/Hydrophilic Ultrathin Graphene Oxide Membrane as Actuator and Conformable Patch for Heart Repair

A conductive engineered cardiac patch (ECP) can reconstruct the biomimetic regenerative microenvironment of an infarcted myocardium. Direct ink writing (DIW) and 3D printing can produce an ECP with precisely controlled microarchitectures. However, developing a printed ECP with high conductivity and flexibility for gapless attachment to conform to epicardial geometry remains a challenge. Herein, an asymmetrical DIW hydrophobic/hydrophilic membrane using heat-processed graphene oxide (GO) ink is developed. The Masked spin coating method is also developed that leads to a microscale GO (hydrophilic)/reduced GO (rGO, hydrophobic) physiological sensor, as well as a macroscale moisture-driven GO/rGO actuator. Depositing mussel-inspired polydopamine (PDA) coating on the one side of the DIW rGO , the ultrathin (approximately 500 nm) PDA-rGO (hydrophilic)/rGO (hydrophobic) microlattice (DrGOM) ECP is bestowed with the flexibility and moisture-responsive actuation that allows gapless attachment to the curved surface of the epicardium. Conformable DrGOM exhibits a promising therapeutic effect on rats' infarcted hearts through conductive microenvironment reconstruction and improved neovascularization.

Automated summary

An asymmetrical DIW hydrophobic/hydrophilic membrane was developed using heat-processed graphene oxide (GO) ink. Additionally, a Masked spin coating method was utilized to create a microscale GO/hydrophilic reduced GO (rGO) physiological sensor and a macroscale moisture-driven GO/rGO actuator. Depositing mussel-inspired polydopamine (PDA) coating on the one side of the DIW rGO resulted in a flexible and moisture-responsive PDA-rGO/hydrophilic rGO microlattice (ECP) that could attach to the curved surface of the epicardium without gaps. This conformable ECP demonstrated promising therapeutic effects on rats' infarcted hearts by reconstructing the conductive microenvironment and enhancing neovascularization.