Department of Radiology, The First Hospital of Shanxi Medical University, Shanxi Medical University, Taiyuan, China; Division of Cardiac Surgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada; Toronto General Research Institute, Division of Cardiovascular Surgery, University Health Network, Toronto, Ontario, Canada.
Division of Cardiac Surgery, Department of Surgery, University of Toronto, Toronto, Ontario, Canada; Toronto General Research Institute, Division of Cardiovascular Surgery, University Health Network, Toronto, Ontario, Canada.
J Heart Lung Transplant. 2018 Jul;37(7):912-924. doi: 10.1016/j.healun.2017.12.011. Epub 2017 Dec 20.
Both stable and biodegradable biomaterials have been used to surgically repair congenital cardiac defects. However, neither type of biomaterial can conduct electrical activity. We evaluated the conductivity and efficacy of a newly synthesized conductive polypyrrole-chitosan (Ppy+Chi) gelfoam patch to support cardiomyocyte (CM) viability and function in vitro and to surgically repair a cardiac defect in vivo.
Ppy+Chi was incorporated into gelfoam (Gel) to form a 3-dimensional conductive patch. In vitro, patch characteristics were evaluated and biocompatibility and bioconductivity were investigated by culturing neonatal rat CMs on the patches. In vivo, a full-thickness right ventricular outflow tract defect was created in rats and the patches were implanted. Four weeks after patch repair, cardiac electrical activation and conduction velocity were evaluated using an optical mapping system.
In vitro, the Ppy+Chi+Gel patch had a higher mean breaking stress than the Gel or Chi+Gel patches, and the highest conductivity. None of the patches altered cell growth. The Ca transient velocity of CMs cultured on the Ppy+Chi+Gel patch was 2.5-fold higher than that of CMs cultured on the Gel or Chi+Gel patches. In vivo, optical mapping at 4 weeks post-implantation demonstrated that Ppy+Chi+Gel patch-implanted hearts had faster conduction velocities, as measured on the epicardial surface. Continuous electrocardiographic telemetry did not reveal any pathologic arrhythmias after patch implantation. Ex-vivo patch conductivity testing also revealed that the Ppy+Chi+Gel patch was more conductive than the Gel and Chi+Gel patches.
The Ppy+Chi+Gel patch was biocompatible, safe and conductive, making it an attractive candidate for a new biomaterial platform for cardiac surgical repair to preserve synchronous ventricular contraction.
稳定和可生物降解的生物材料都被用于心脏先天性缺损的外科修复。然而，这两种生物材料都不具备传导电活动的能力。我们评估了一种新合成的导电性聚吡咯-壳聚糖（Ppy+Chi）明胶海绵贴片在体外支持心肌细胞（CM）活力和功能以及在体内修复心脏缺损的效果和传导性能。
将 Ppy+Chi 掺入明胶海绵（Gel）中形成三维导电贴片。在体外，评估贴片的特性，并通过在贴片上培养新生大鼠的 CM 来研究其生物相容性和生物导电性。在体内，制作大鼠全层右心室流出道缺损，并植入贴片。在贴片修复 4 周后，使用光学映射系统评估心脏电激活和传导速度。
在体外，Ppy+Chi+Gel 贴片的平均断裂应力高于 Gel 或 Chi+Gel 贴片，且导电性最高。这些贴片都没有改变细胞生长。培养在 Ppy+Chi+Gel 贴片上的 CM 的 Ca 瞬态速度比培养在 Gel 或 Chi+Gel 贴片上的 CM 快 2.5 倍。在体内，植入后 4 周的光学映射显示，Ppy+Chi+Gel 贴片植入的心脏在心脏表面具有更快的传导速度。植入贴片后连续的心电图遥测未发现任何病理性心律失常。离体贴片导电性测试也显示 Ppy+Chi+Gel 贴片比 Gel 和 Chi+Gel 贴片更具导电性。
Ppy+Chi+Gel 贴片具有生物相容性、安全性和导电性，是一种有吸引力的候选材料，可用于心脏外科修复的新生物材料平台，以保持心室同步收缩。
