Generation of a vascularised heart patch for cardiac regeneration

干细胞来源的心肌细胞（CMs）移植已成为一个潜在的新的治疗选择心力衰竭患者在过去的20年。已在小型和大型动物模型中证明了疗效。一种方法是移植体外工程心脏组织（EHT）补片。虽然EHT移植已被证明可以显著改善心肌梗死（MI）后的心功能，但移植物的大小和相关的功能改善仍然相对较小。这种方法的一个问题是移植后功能细胞的大量损失。原因是移植后直接缺乏氧气供应。缺失或非常缓慢的血管形成导致移植物中大部分细胞的死亡。该项目旨在促进移植后立即有效和实际可行的组织血管化。为此，将采用潜在的促血管生成心外膜细胞（EPI）和内皮细胞（EC）来实现多细胞方法的产生，每种细胞在胚胎发育期间的心脏血管化和成熟中发挥重要作用。Sinha教授小组的初步工作表明，CM与EPI的共同移植促进了心脏功能的改善，组织中心肌细胞的成熟和受体血管化的增加。此外，开发了一种新的冻干胶原蛋白贴片基质，其在鸡胚中血管化，并在掺入CM后改善了大鼠MI模型的心脏功能。基于这项初步工作，该项目将生产一种具有合适载体基质和优化血管化潜力的多细胞EHT贴剂。为此，将首先在共培养物中优化三种细胞类型（EPI、EC、CM）的组成。随后，将在不同的载体材料上测试合适的共培养物，以确定哪种基质为细胞存活提供最佳特性。为此，将EHT皮下移植到成年大鼠的背部。如果血管化成功并且可以确认细胞存活，则将在研究中将EHT移植到受伤的大鼠心脏上，以研究优化的EHT贴片是否可以血管化并显着增加心脏功能。该项目将证明多细胞EHT贴片中不同细胞类型对血管形成、成熟、功能的影响，从而证明这种构建体的生物学相关性。因此，该项目为心脏再生治疗领域的知识和进步做出了重要贡献。

The transplantation of stem cell-derived cardiomyocytes (CMs) has emerged as a potentially novel therapy option for heart failure patients within the past 20 years. Efficacy has been demonstrated in both small and large animal models. One approach is the transplantation of in vitro engineered heart tissue (EHT) patches. Although transplantation of EHT has been shown to significantly improve cardiac function after myocardial infarction (MI), but the size of the grafts and the associated functional improvement remains relatively small. One problem with this approach is the high loss of functional cells after transplantation. The reason for this is the lack of oxygen supply directly after transplantation. The missing or very slow vascularisation leads to the death of a large part of the cells in the transplant. The project applied for here aims to promote efficient and practically feasible vascularisation of the tissue immediately after transplantation. For this purpose, the generation of a multicellular approach will be pursued with potentially proangiogenic epicardial cells (EPIs) and endothelial cells (ECs), each playing an important role in vascularisation and maturation of the heart during embryological development. Preliminary work by Prof. Sinha's group has shown that co-transplantation of CMs with EPIs promotes improved cardiac function, maturation of cardiomyocytes in the tissue and increased vascularisation on the part of the recipient. In addition, a new patch matrix of freeze-dried collagen was developed, which was vascularised in the chicken embryo and improved cardiac function in the rat MI model after incorporation of CMs. Based on this preliminary work, this project will produce a multicellular EHT patch with a suitable carrier matrix and optimised vascularisation potential. For this purpose, the composition of three cell types (EPIs, ECs, CMs) will first be optimised in a co-culture. Subsequently, the suitable co-culture will be tested on different carrier materials to determine which of the matrices offers the best properties for cell survival. For this purpose, the EHT will be transplanted subcutaneously into the dorsum of adult rats. If vascularisation is successful and cell survival can be confirmed, EHTs will be transplanted onto injured rat hearts in a study to investigate whether the optimised EHT patches can vascularise and significantly increase cardiac function. This project will demonstrate the influence of different cell types in a multicellular EHT patch on vascularisation, maturation, function and thus the biological relevance of such a construct. This project thus makes an important contribution to knowledge and progress in the field of cardiac regenerative therapy.