Cardiac Function in Rat Model Improved by 3D Printed Cardiac Patch

A 3D printed cardiac patch may improve cardiac function in patients with a myocardial infarction, based on results observed in a rat model, according to new research.

“Stem cell injection therapy in animal models has been investigated extensively,” said study author Enoch Yeung, BDS, MBBS, of Johns Hopkins University in Baltimore, Md., who presented the findings. However, this form of therapy has largely poor retention rates for the injected stem cells. Yeung and his colleagues tried a different solution.

“Our research team has demonstrated the creation of a scaffold-free cardiac patch with organized electric activity in vivo,” said Yeung. “The objective of this study was to evaluate the in vivo regenerative potential of the bio 3D bioprinted cardiac tissue,” the study authors wrote.

Six patches were implanted into rat myocardial infarction models (experimental group), and there were six control group models that did not receive a patch (control group). Four weeks after implantation, researchers performed echocardiography, histology, scar area analysis and quantification of vascularization. At follow-up, the experimental group had a 100% survival rate, compared to 83% in the control group. The experimental group had a higher mean vessel count within the infarcted area compared to the control group (15.13 vs. 7.17, P = 0.001), as well as a much smaller scar area than the control group (10.6% vs. 19.39%, P = 0.048). The patch group also had greater ejection fraction percentage (50.0% vs. 40.1%, P = 0.36) and cardiac output (104.6 mL/min vs 68.6 mL/min, P = 0.1) than the control group. Mean left ventricular mass was 860.9 grams in the patch group and 1,150.5 grams in the control group (P = 0.1).

Yeung added that “the  patch implantation provides significant scar tissue reduction” in the infarcted area.

“These patches were engrafted onto rat hearts within a myocardial infarction model, and they achieved a remarkable 95% cell viability at four weeks, with increased vascularity, decreased scar [tissue] and a trend toward improved cardiac function,” discussant Joseph Turek, MD, PhD, of Duke University Medical Center in Durham, N.C., said of the results.