Endothelial Network Formation Within Human Tissue-Engineered Skeletal Muscle

Dacha Gholobova, Lieselot Decroix, Vicky Van Muylder, Linda Desender, Melanie Gerard, Gilles Carpentier, Herman Vandenburgh, Lieven Thorrez
2015 Tissue Engineering. Part A  
The size of in vitro engineered skeletal muscle tissue is limited due to the lack of a vascular network in vitro. In this paper, we report tissue engineered skeletal muscle consisting of human aligned myofibers with interspersed endothelial networks. We extend our bio-artificial muscle (BAM) model by co-culturing human muscle progenitor cells with human umbilical vein endothelial ce lls (HUVECs) in a fibrin extracellular matrix. First, the optimal medium conditions for co-culturing myoblasts
more » ... h HUVECs were determined in a fusion assay. Endothelial growth medium proved the best compromise for the coculture, without affecting myoblast fusion index. Second, both cell types were cocultured in a BAM maintained under tension to stimulate myofiber alignment. We then tested different total cell numbers containing 50% HUVECs and found that BAMs with a total cell number of 2.10 6 resulted in well aligned and densely packed myofibers while allowing for improved interspersed endothelial network formation. Third, we compared different myoblast-HUVEC ratios. Including higher numbers of myoblasts improved endothelial network formation at lower total cell density, however improvement of network characteristics reached a plateau when 1.10 6 or more myoblasts were present. Finally, addition of Matrigel to the fibrin ECM did not enhance overall myofiber and endothelial network formation. Therefore, in our BAM model, we suggest the use of a fibrin extracellular matrix containing 2.10 6 cells of which 50-70% are muscle cells. Optimizing these coculture conditions allows for a physiologically more relevant muscle model and paves the way towards engineering of larger in vitro muscle constructs.
doi:10.1089/ten.tea.2015.0093 pmid:26177063 pmcid:PMC4605445 fatcat:fqp6c3qs3fh7vgxfaocwz4c2ju