Sequential use of human‐derived medium supplements favours cardiovascular tissue engineering

Abstract

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. Cells were isolated from venous grafts of 10 patients and expanded in media supplemented with PL or HS, to determine proliferation rates and expression of genes related to collagen production and maturation. Zymography was used to assess protease expression. Collagen contraction assays were used as a two-dimensional (2D) model for matrix contraction. As a prove of principle, 3D tissue culture and tensile testing was performed for two patients, to determine tissue strength. Cell proliferation was lower in HS-supplemented medium than in PL medium. The HS cells produced less active matrix metallo-proteinase 2 (MMP2) and showed increased matrix contraction as indicated by gel contraction assays and 3D-tissue culture. Tensile testing showed increased strength for tissues cultured in HS when compared to PL. This effect was more pronounced if cells were sequentially cultured in PL, followed by tissue culture in HS. These data suggest that sequential use of PL and HS as substitutes for FBS in culture medium for cardiovascular tissue engineering results in improved cell proliferation and tissue mechanical properties, as compared to use of PL or HS apart.

Serum and supplement optimization for EU GMP‐compliance in cardiospheres cell culture

“…To try all possible alternatives to FBS, we tested some commercially available serum-free formulation and PL as well, which have been also described in other stem cell models 12 , 19 , 50 – 52 , without any success in primary explant culture or CS viability (data not shown). Interestingly, sequential use of PL and HS has been shown effective for cardiovascular tissue engineering approaches on collagen scaffolds 53 , but, despite CS being suitable for tissue engineering approaches as well 54 , 55 , our results suggest that this kind of media formulation would not be effective with this cell model.…”