Li Hanjun, Shadrin Ilya, Helfer Abbigail, Heman Karen, Rao Lingjun, Curtis Caroline, Palmer Gregory M, Bursac Nenad
Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
Department of Radiation Oncology, Cancer Biology Division at Duke University Medical Center, Duke University, NC 27708, USA.
Acta Biomater. 2024 Nov 10. doi: 10.1016/j.actbio.2024.11.014.
Engineered human cardiac tissues hold great promise for disease modeling, drug development, and regenerative therapy. For regenerative applications, successful engineered tissue engraftment in vivo requires rapid vascularization and blood perfusion post-implantation. In the present study, we engineered highly functional, vascularized cardiac tissues ("cardiopatches") by co-culturing human induced pluripotent stem cell-derived cardiomyocytes (hiPSCCMs) and endothelial cells (hiPSC-ECs) in optimized serum-free media. The vascularized cardiopatches displayed stable capillary networks over 4 weeks of culture, the longest reported in the field, while maintaining high contractile stress (>15 mN/mm) and fast conduction velocity (>20 cm/s). Robustness of the method was confirmed using two distinct hiPSC-EC sources. Upon implantation into dorsal-skinfold chambers in immunocompromised mice, in vitro vascularized cardiopatches exhibited improved angiogenesis compared to avascular implants. Significant lumenization of the engineered human vasculature and anastomosis with host mouse vessels yielded the formation of hybrid human-mouse capillaries and robust cardiopatch perfusion by blood. Moreover, compared to avascular tissues, the implanted vascularized cardiopatches exhibited significantly higher conduction velocity and Ca transient amplitude, longitudinally monitored in live mice for the first time. Overall, we demonstrate successful 4-week vascularization of engineered human cardiac tissues without loss of function in vitro, which promotes tissue functionality upon implantation in vivo. STATEMENT OF SIGNIFICANCE: Complex interactions between cardiac muscle fibers and surrounding capillaries are critical for everyday function of the heart. Tissue engineering is a powerful method to recreate functional cardiac muscle and its vascular network, which are both lost during a heart attack. Our study demonstrates in vitro engineering of dense capillary networks within highly functional engineered heart tissues that successfully maintain the structure, electrical, and mechanical function long-term. In mice, human capillaries from these engineered tissues integrate with host mouse capillaries to allow blood perfusion and support improved implant function. In the future, the developed vascularized engineered heart tissues will be used for in vitro studies of cardiac development and disease and as a potential regenerative therapy for heart attack.
工程化的人类心脏组织在疾病建模、药物开发和再生治疗方面具有巨大潜力。对于再生应用而言，工程化组织在体内的成功植入需要在植入后迅速实现血管化和血液灌注。在本研究中，我们通过在优化的无血清培养基中共培养人诱导多能干细胞衍生的心肌细胞（hiPSCCMs）和内皮细胞（hiPSC-ECs），构建了功能高度完善、血管化的心脏组织（“心脏贴片”）。这些血管化的心脏贴片在长达4周的培养过程中展现出稳定的毛细血管网络，这是该领域报道的最长培养时间，同时保持了较高的收缩应力（>15 mN/mm）和快速传导速度（>20 cm/s）。使用两种不同的hiPSC-EC来源证实了该方法的稳健性。将体外血管化的心脏贴片植入免疫缺陷小鼠的背皮褶腔后，与无血管植入物相比，其血管生成情况得到改善。工程化的人类血管系统显著形成管腔，并与宿主小鼠血管吻合，从而形成了人鼠混合毛细血管，并实现了心脏贴片由血液进行的强劲灌注。此外，与无血管组织相比，植入的血管化心脏贴片展现出显著更高的传导速度和钙瞬变幅度，这是首次在活体小鼠中进行纵向监测。总体而言，我们证明了工程化的人类心脏组织在体外成功实现了为期4周的血管化且未丧失功能，这在植入体内后促进了组织功能。重要性声明：心肌纤维与周围毛细血管之间的复杂相互作用对于心脏的日常功能至关重要。组织工程是一种强大的方法，可用于重建功能性心肌及其血管网络，而这些在心脏病发作期间均会丧失。我们的研究展示了在功能高度完善的工程化心脏组织内进行密集毛细血管网络的体外工程构建，该组织能够长期成功维持结构、电学和机械功能。在小鼠体内，这些工程化组织中的人类毛细血管与宿主小鼠毛细血管整合，以实现血液灌注并支持植入物功能的改善。未来，所开发的血管化工程化心脏组织将用于心脏发育和疾病的体外研究，并作为心脏病发作的潜在再生治疗手段。
