Despite the advantage of preserving ECM architecture, acellular xenogeneic valves may retain a slight immunogenicity, mainly due to the native fibrous proteins, collagen, and elastin. Preservation of matrix integrity and the effect of different detergents used for cell removal have been studied using new techniques such as laser-scanning calorimetry. Morphological, mechanical, and biochemical characteristics of decellularized scaffolds, obtained from biological valves, are also under investigation. 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.īioreactors, Tissue engineering, Heart valves, Dynamic conditioning 1 Overview of tissue engineering applied to bioreactorsĬomplete and exhaustive characterization of cell populations in native semilunar valves as well as of the extracellular matrix (ECM) composition is still in progress. These concepts have led scientists to design bioreactors to mimic the in vivo environment of heart valves. Biomechanical stimuli have significant impact on cell behavior including in vitro differentiation, and physiological hemodynamic conditioning has been found to promote new tissue development. Cell seeding and repopulation of acellular heart valve scaffolds, biological and polymeric, appears as a promising way to create a living valve. Moreover, neither mechanical nor bioprostheses are able to follow children’s body growth. 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. 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. 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.
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