Background Most cardiac regenerative approaches can restore injured heart muscles.In this study,we investigated iffibrin sealant could help neonatal cardiomyocytes restore myocardial function in a rat model of myocardial infarction.Methods The left anterior descending artery in adult female Sprague-Dawley(SD)rats was ligated to make amyocardial infarction model.Neonatal ventricular cardiomyocytes from one-day male SD rats were isolated,labeled andcultured.The cells were injected into the infarcted area three weeks later.The animals were randomized into fourrecipient groups:(1)cardiomyocytes plus fibrin sealant(group CF,n=10);(2)cardiomyocytes alone(group C,n=10);(3)fibrin sealant recipients alone(group F,n=10);(4)control group(n=10).Four weeks after transplantation,echocardiography and Langerdoff model were used to assess heart function.Immunohistochemical staining andpolymerase chain reaction(PCR)were performed to track the implanted cardiomyocytes and detect the sex-determiningregion Y gene on Y chromosome.Results Echocardiography showed the fraction shortening(FS)in groups CF,C,F and control group was(27.80±6.32)%,(22.29±4.54)%,(19.24±6.29)% and(20.36±3.29)% respectively with statistically significant differences ingroup CF compared with the other groups(P<0.05).The Langendoff model revealed that the left ventricular developmentof peak pressure(LVDPmax,mmHg)in groups CF,C,F and control group was 104.81±17.05,80.97±21.60,72.07±26.17and 71.42±17.55 respectively with statistically significant differences in group CF compared with the other groups(P<0.05).Pathological examination and PCR indicated that transplanted cardiomyocytes in group CF survived betterthan those in the other groups.Conclusion Transplanted neonatal cardiomyocytes plus fibrin sealant can survive in myocardial infarctioned area andimprove heart function greatly in rat models. Background Most cardiac regenerative approaches can restore injured heart muscles. In this study, we investigated iffibrin sealant could help neonatal cardiomyocytes restore myocardial function in a rat model of myocardial infarction. Methods The left anterior descending artery in adult female Sprague-Dawley (SD) rats was ligated to make amyocardial infarction model. Neonatal ventricular cardiomyocytes from one-day male SD rats were isolated, labeled and cultured. The cells were injected into the infarcted area three weeks later. The animals were randomized into fourrecipient groups: (1) cardiomyocytes plus fibrin sealant (group CF, n = 10); (2) cardiomyocytes alone (group C, n = 10); (3) fibrin sealant recipients alone .Fours weeks after transplantation, echocardiography and Langerdoff model were used to assess heart function. Immunohistochemical staining and polymerase chain reaction (PCR) were performed to track the implanted cardiomyocytes and detect the sex-determiningregion Y gene on Y chromosome. Results Echocardiography showed the fraction shortening (FS) in groups CF, C, F and control group was (27.80 ± 6.32)%, (22.29 ± 4.54)%, (19.24 ± 6.29)% and (20.36 ± 3.29)% respectively with significant differences in group CF compared with the other groups (P <0.05). Langendoff model revealed that the left ventricular development of peak pressure (LVDPmax, mmHg) in groups CF, C, F and control group was 104.81 ± 17.05, 80.97 ± 21.60, 72.07 ± 26.17 and 71.42 ± 17.55 respectively with significant significant differences in group CF compared with the other groups (P <0.05). Pathological examination and PCR showed that transplanted cardiomyocytes in group CF survived betterthan those in the other groups .Conclusion Transplanted neonatal cardiomyocytes plus fibrin sealant can survive in myocardial infarctioned area andimprove heart function greatly in rat models.