@article {19620, title = {Endothelial - Smooth Muscle - Fibroblastic co-culture systems prospecting the development of Tissue-Engineered Vascular Grafts}, booktitle = {29th Annual Meeting of the European Society for Biomaterials}, year = {2018}, month = {2018-09-10 00:00:00}, address = {Maastricht, Netherlands}, abstract = {

INTRODUCTION

Cardiovascular diseases, including coronary artery diseases, are a major cause of mortality worldwide. Consequently, there is a pressing need to develop small-diameter vascular vessels for bypass surgery and other vascular reconstructive procedures. Tissue engineering offers the prospect of being able to meet this medical demand, as it allows the development of structurally complex blood vessels substitutes1. Accordingly, the ultimate aim of this work is to develop small diameter vascular substitutes based on layering multiple cell types (i.e. endothelial, smooth muscle and fibroblastic cells)2.

METHODS

Electrospun nanofibrous meshes, which restrict cell migration although enabling biochemical communication3, were used as substrate. Co-culture systems of human endothelial-smooth muscle cells and fibroblastic-smooth muscle cells were established. These co-cultures were then assembled to develop a tri-culture system, which mimics the structural organization of a blood vessel.

RESULTS AND DISCUSSION

In both co-culture conditions was possible to observe a viable and proliferative cell population through the 7 days of culture. From the histological (Figure 1) and immunofluorescence micrographs of the co-culture systems was possible to observe that the endothelial, smooth muscle and fibroblastic cells remained phenotypically stable, even in the presence of another cell type. Concerning the tri-culture system, cell viability and proliferation presents a similar trend to the co-cultures. Interestingly, the tri-culture system presents values of protein synthesis much higher than the co-cultures, mostly of collagen. Quantification of lineage-specific growth factors, namely vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), on conditioned media of co- and tri-culture systems demonstrated a synergistic interplay between VEGF and bFGF. VEGF is mainly expressed by smooth muscle cells, which leads to increase levels in the co- and tri-culture systems. A similar trend is observed with the levels of bFGF, expectedly produced by the fibroblast cells. By its side, PDGF levels remain unaltered among conditions. Altogether, these results demonstrate the potential inter-cellular communication mediated by these soluble proteins.

CONCLUSION

This study demonstrated the fundamental importance of the intercellular crosstalk between endothelial, smooth muscle and fibroblastic cells, in the mechanism of vessels{\textquoteright} regeneration. These experimental results reinforce the potential of a tri-culture system in the development of tissue engineered blood vessel substitutes.

}, keywords = {co- and tri-culture systems, growth factors secretion, intercellular communication, vascular substitute; extracellular matrix synthesis}, author = {Felizardo, T. and Neves, N. M. and Martins, A. and Reis, R. L.} }