Magnetostriction enhanced self-powered nanofiber sheet as cardiac patch with magnetoelectric synergistic effect on actuating Na+ k+-ATPase

[Display omitted] •Developed a potential magnetostrictive cardiac patch, CoFe2O4-PVDF, for injured myocardium.•Enhanced piezoelectric effect due to the deformation of CoFe2O4 and increased β phase and crystallinity of PVDF.•The magnetoelectric cues of CoFe2O4-PVDF synergistically positively influence on cardiomyocytes.•A new mechanism of magnetoelectric cues included steroid hormone biosynthesis, Na+ K+-ATPase and intracelluar Ca2+. Cardiac tissue engineering has great promise in the treatment of heart disease. Aiming to develop the novel magnetoelectric cardiac patch for improving the non-conduction of injured myocardium after myocardial infarction, the self-powered nanofiber sheet was electro-spun by doping magnetostrictive CoFe2O4 in piezoelectric Poly (vinylidene fluoride) (PVDF). The piezoelectric ratios increased several folds with the doping of CoFe2O4 due to the increased β phase and crystallinity of CoFe2O4-PVDF confirmed by experimental data. Molecular Dynamics and Finite Element Simulation demonstrated that non-β phase transformed to β phase of PVDF with doping CoFe2O4 and the deformation of CoFe2O4 enhanced the piezoelectric effect of PVDF, respectively. The proliferation and spread area of Doxorubicin-induced oxidative stress injured cardiomyocytes, H9c2 cells, were significantly improved under magnetoelectric cue compared with those without magnetoelectric cue when co-cultured with CoFe2O4-PVDF. Importantly, a new mechanism pathway of magnetoelectric cue on cardiomyocytes has been found, including up-regulating of steroid hormone biosynthesis, enhancing of sodium–potassium enzyme, and increasing of intracellular Ca2+, which would trigger the cardiomyocyte contraction to overcome the non-conduction of injured cardiomyocytes by RNA-seq transcriptome sequencing, Polymerase Chain Reaction and downstream expression analysis. Hence, this CoFe2O4-PVDF composite nanofiber sheet would be potentially used as the magnetoelectric cardiac patch to treat injured myocardium after myocardial infarction clinical.