Rationale: Researches on conductive engineering cardiac patch (ECP) for myocardial infarction (MI) treatment have achieved some progress in the animal while the availability of traditional conductive materials in ECP is still limited because of their controversial cytotoxicity. Here we aim to introduce a novel hydrophilic biocompatible conductive material: MXene Ti₂C and mussel-inspired dopamine into PEGDA-GelMA cryogel to construct a bio-functional ECP of which the property closes to natural heart for the repair of MI.

Method: MXene Ti₂C was etched from MAX Ti₂AlC, then uniformly dispersed into the prepolymer composed with dopamine-N′, N′-methylene-bisacrylamide, methacrylate-gelatin, and poly (ethylene glycol) diacrylate by simple water bath sonication. The resilient conductive Ti₂C-cryogel was fabricated by chemical cryogelation. The conductive ECP was evaluated in vitro and transplanted to the MI rat model for MI treatment.

Results: In vitro, the 3D vessels-shape framework was observed in Ti₂C-8-cryogel which was seeded with rats aortic endothelial cells. When the Ti₂C-cryogels were cocultured with CMs, remarkably aligned sarcomere and the primitive intercalated disc between the mature CMs were formed on day 7. The as-prepared Ti₂C-8-cryogel ECP also demonstrated rapid calcium transients and synchronous tissue-like beating. When transplanted into the infarcted heart of the MI rat model, the Ti₂C-8-cryogel ECP could improve the cardiac function, reduce the infarct size, and inhibit the inflammatory response. Obvious vasculation especially newly formed arteriole was also found.

Conclusion: A novel conductive Ti₂C-embedded cardiac patch with suitable conductivity and the mechanical property was developed and could be served as an ideal candidate for MI repair.

原理：用于动物心肌梗死（MI）治疗的导电性工程性心脏贴片（ECP）的研究已在动物中取得了一些进展，而由于有争议的细胞毒性，ECP中传统导电材料的可用性仍然受到限制。在这里，我们旨在将一种新型的亲水性生物相容性导电材料：MXene Ti ₂ C和贻贝启发的多巴胺引入PEGDA-GelMA冷冻凝胶中，以构建一种生物功能性ECP，其性能接近自然心脏，可修复MI。

方法：从MAX Ti ₂ AlC中蚀刻出MXene Ti ₂ C ，然后通过简单的水浴超声处理将其均匀分散到由多巴胺-N'，N'-亚甲基-双丙烯酰胺，甲基丙烯酸酯-明胶和聚乙二醇二丙烯酸酯组成的预聚物中。通过化学冷冻凝胶化制备弹性导电的Ti ₂ C-cryogel。在体外评估了传导性ECP ，并将其移植到MI大鼠模型中进行MI治疗。

结果：在体外，在接种有大鼠主动脉内皮细胞的Ti ₂ C-8-cryogel中观察到3D血管形状的骨架。当Ti ₂ C-cryogels与CMs共培养时，显着排列的肌节和成熟CMs之间的原始插入盘在第7天形成。制备的Ti ₂ C-8-cryogel ECP还显示出快速的钙瞬变和同步组织。像跳动。当将其移植到MI大鼠模型的梗塞心脏中时，Ti ₂ C-8-cryogel ECP可以改善心脏功能，减小梗塞面积并抑制炎症反应。还发现明显的血管收缩，尤其是新形成的小动脉。

结论：开发了一种新型的具有导电性和机械性能的导电性Ti ₂ C嵌入式心脏贴片，可作为MI修复的理想候选者。