Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Via Giustiniani 2, 35128 Padova, Italy.
Eur J Cardiothorac Surg. 2011 Apr;39(4):523-31. doi: 10.1016/j.ejcts.2010.07.030. Epub 2010 Dec 15.
The development of viable and functional tissue-engineered heart valves (TEHVs) is a challenge that, for almost two decades, the scientific community has been committed to face to create life-lasting prosthetic devices for treating heart valve diseases. One of the main drawbacks of tissue-based commercial substitutes, xenografts and homografts, is their lack of viability, and hence failure to grow, repair, and remodel. In adults, the average bioprostheses life span is around 13 years, followed by structural valve degeneration, such as calcification; in pediatric, mechanical valves are commonly used instead of biological substitutes, as in young patients, the mobilization of calcium, due to bone remodeling, accelerates the calcification process. Moreover, neither mechanical nor bioprostheses are able to follow children's body growth. Cell seeding and repopulation of acellular heart valve scaffolds, biological and polymeric, appears as a promising way to create a living valve. Biomechanical stimuli have significant impact on cell behavior including in vitro differentiation, and physiological hemodynamic conditioning has been found to promote new tissue development. These concepts have led scientists to design bioreactors to mimic the in vivo environment of heart valves. Many different types of somatic and stem cells have been tested for colonizing both the surface and the core of the valve matrix but controversial results have been achieved so far.
开发具有活力和功能的组织工程心脏瓣膜 (TEHV) 是科学界近二十年来一直致力于解决的挑战，以创建用于治疗心脏瓣膜疾病的持久假体装置。基于组织的商业替代品、异种移植物和同种移植物的主要缺点之一是它们缺乏活力，因此无法生长、修复和重塑。在成年人中，平均生物假体的使用寿命约为 13 年，随后会出现结构性瓣膜退化，如钙化；在儿科中，机械瓣膜通常被用于替代生物替代品，因为在年轻患者中，由于骨骼重塑导致的钙动员会加速钙化过程。此外，机械瓣膜和生物假体都无法适应儿童的身体生长。细胞接种和去细胞心脏瓣膜支架的再细胞化，无论是生物的还是聚合的，都似乎是创造活瓣的一种有前途的方法。生物力学刺激对细胞行为有重大影响，包括体外分化，并且已经发现生理血液动力学调节可以促进新组织的发育。这些概念促使科学家设计生物反应器来模拟心脏瓣膜的体内环境。已经测试了许多不同类型的体细胞和干细胞来定植瓣膜基质的表面和核心，但迄今为止取得的结果仍存在争议。
