Variation in tissue outcome of ovine and human engineered heart valve constructs: relevance for tissue engineering.

Aim: Clinical application of tissue engineered heart valves requires precise control of the tissue culture process to predict tissue composition and mechanical properties prior to implantation, and to understand the variation in tissue outcome. To this end we investigated cellular phenotype and tissue properties of ovine (n = 8) and human (n = 7) tissue engineered heart valve constructs to quantify variations in tissue outcome within species, study the differences between species and determine possible indicators of tissue outcome.

Materials & Methods: Tissue constructs consisted of polyglycolic acid/poly-4-hydroxybutyrate scaffolds, seeded with myofibroblasts obtained from the jugular vein (sheep) or the saphenous vein (from humans undergoing cardiac surgery) and cultured under static conditions.

Sequential use of human-derived medium supplements favours cardiovascular tissue engineering.

For clinical application of tissue engineering strategies, the use of animal-derived serum in culture medium is not recommended, because it can evoke immune responses in patients. We previously observed that human platelet-lysate (PL) is favourable for cell expansion, but generates weaker tissue as compared to culture in foetal bovine serum (FBS). We investigated if human serum (HS) is a better human supplement to increase tissue strength.

Lack of fibronectin-EDA promotes survival and prevents adverse remodeling and heart function deterioration after myocardial infarction.

Rationale: The extracellular matrix may induce detrimental inflammatory responses on degradation, causing adverse cardiac remodeling and heart failure. The extracellular matrix protein fibronectin-EDA (EIIIA; EDA) is upregulated after tissue injury and may act as a "danger signal" for leukocytes to cause adverse cardiac remodeling after infarction.

Objective: In the present study, we evaluated the role of EDA in regulation of postinfarct inflammation and repair after myocardial infarction.

Decreased mechanical properties of heart valve tissue constructs cultured in platelet lysate as compared to fetal bovine serum.

In autologous heart valve tissue engineering, there is an ongoing search for alternatives of fetal bovine serum (FBS). Human platelet-lysate (PL) might be a promising substitute. In the present article, we aimed to examine the tissue formation, functionality, and mechanical properties of engineered three-dimensional tissue constructs cultured in PL as a substitute for FBS.

Environmental regulation of valvulogenesis: implications for tissue engineering.

Ongoing research efforts aim at improving the creation of tissue-engineered heart valves for in vivo systemic application. Hence, in vitro studies concentrate on optimising culture protocols incorporating biological as well as biophysical stimuli for tissue development. Important lessons can be drawn from valvulogenesis to mimic natural valve development in vitro.

Platelet-lysate as an autologous alternative for fetal bovine serum in cardiovascular tissue engineering.

There is an ongoing search for alternative tissue culture sera to engineer autologous tissues, since use of fetal bovine serum (FBS) is limited under Good Tissue Practice guidelines. We compared FBS with human platelet-lysate (PL) in media for in vitro cell culture. A threefold increase in duplication rate was found when human, saphenous vein-derived myofibroblasts were cultured in PL, whereas expression of marker proteins (alpha-smooth muscle actin, vimentin, desmin, and nonmuscle myosin heavy chain) was similar.