Cell-derived Extracellular Matrix - a promising Biomaterial for in
vitro-vascularization in Adipose Tissue Engineering
Abstract
Tissue constructs of physiologically relevant scale require a vascular
system to maintain cell viability. However, in vitro vascularization of
engineered tissues is still a major challenge. Successful approaches are
based on a feeder layer (FL) to support vascularization. Here, we
investigated whether the supporting effect on the self-assembled
formation of vascular-like structures by microvascular endothelial cells
(mvECs) originates from the FL itself or from its extracellular matrix
(ECM). Therefore, we compared the influence of ECM, either derived from
adipose-derived stem cells (ASCs) or adipogenic differentiated ASCs,
with the classical approaches based on a cellular FL. All cell-derived
ECM (cdECM) substrates enable mvEC growth with high viability.
Vascular-like structure formation was visualized by immunofluorescence
staining of endothelial surface protein CD 31 and can be observed on all
cdECM and FL substrates but not on control substrate collagen I. On
adipogenic differentiated ECM longer and higher branched structures can
be found compared to stem cell cdECM. An increased concentration of
pro-angiogenic factors can be found in cdECM substrates and FL
approaches compared to controls. Finally, expression of proteins
associated with tube formation (E-selectin and thrombomodulin) was
confirmed. These results highlight cdECM as promising biomaterial for in
vitro vascularization in adipose tissue engineering.