Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland.
University Heart Center Zurich, University Hospital Zurich, Zurich, Switzerland.
Sci Transl Med. 2018 May 9;10(440). doi: 10.1126/scitranslmed.aan4587.
Valvular heart disease is a major cause of morbidity and mortality worldwide. Current heart valve prostheses have considerable clinical limitations due to their artificial, nonliving nature without regenerative capacity. To overcome these limitations, heart valve tissue engineering (TE) aiming to develop living, native-like heart valves with self-repair, remodeling, and regeneration capacity has been suggested as next-generation technology. A major roadblock to clinically relevant, safe, and robust TE solutions has been the high complexity and variability inherent to bioengineering approaches that rely on cell-driven tissue remodeling. For heart valve TE, this has limited long-term performance in vivo because of uncontrolled tissue remodeling phenomena, such as valve leaflet shortening, which often translates into valve failure regardless of the bioengineering methodology used to develop the implant. We tested the hypothesis that integration of a computationally inspired heart valve design into our TE methodologies could guide tissue remodeling toward long-term functionality in tissue-engineered heart valves (TEHVs). In a clinically and regulatory relevant sheep model, TEHVs implanted as pulmonary valve replacements using minimally invasive techniques were monitored for 1 year via multimodal in vivo imaging and comprehensive tissue remodeling assessments. TEHVs exhibited good preserved long-term in vivo performance and remodeling comparable to native heart valves, as predicted by and consistent with computational modeling. TEHV failure could be predicted for nonphysiological pressure loading. Beyond previous studies, this work suggests the relevance of an integrated in silico, in vitro, and in vivo bioengineering approach as a basis for the safe and efficient clinical translation of TEHVs.
心脏瓣膜病是全球发病率和死亡率的主要原因。由于目前的人工心脏瓣膜不具有再生能力,属于非生物性质,因此具有相当大的临床局限性。为了克服这些局限性,人们提出了心脏瓣膜组织工程(TE)技术,旨在开发具有自我修复、重塑和再生能力的活的、类似天然的心脏瓣膜,作为下一代技术。心脏瓣膜组织工程的一个主要障碍是,依赖于细胞驱动的组织重塑的生物工程方法具有很高的复杂性和变异性,这限制了其在临床上的相关、安全和强大的解决方案。对于心脏瓣膜 TE,由于不受控制的组织重塑现象,如瓣叶缩短,导致其在体内的长期性能受到限制,这通常会导致瓣膜失效,而不管用于开发植入物的生物工程方法如何。我们测试了这样一个假设,即把计算启发式的心脏瓣膜设计整合到我们的 TE 方法中,可以引导组织重塑,从而实现组织工程心脏瓣膜(TEHV)的长期功能。在一个具有临床和监管相关性的绵羊模型中,使用微创技术作为肺动脉瓣置换物植入的 TEHV 通过多模态体内成像和全面的组织重塑评估进行了为期 1 年的监测。TEHV 表现出良好的长期体内保留性能和重塑,与天然心脏瓣膜相似,这与计算模型的预测和一致。非生理压力负荷可以预测 TEHV 的失效。与以前的研究相比,这项工作表明,基于计算、体外和体内生物工程方法的综合方法是 TEHV 安全高效的临床转化的基础。