Conditioned medium produced by fibroblasts cultured in low oxygen pressure allows the formation of highly structured capillary-like networks in fibrin gels

Abstract

Tissue engineering is an emerging and promising concept to replace or cure failing organs, but its clinical translation currently encounters issues due to the inability to quickly produce inexpensive thick tissues, which are necessary for many applications. To circumvent this problem, we postulate that cells secrete the optimal cocktail required to promote angiogenesis when they are placed in physiological conditions where their oxygen supply is reduced. Thus, dermal fibroblasts were cultivated under hypoxia (2% O2) to condition their cell culture medium. The potential of this conditioned medium was tested for human umbilical vein endothelial cell proliferation and for their ability to form capillary-like networks into fibrin gels. The medium conditioned by dermal fibroblasts under hypoxic conditions (DF-Hx) induced a more significant proliferation of endothelial cells compared to medium conditioned by dermal fibroblasts under normoxic conditions (DF-Nx). In essence, doubling time for endothelial cells in DF-Hx was reduced by 10.4% compared to DF-Nx after 1 week of conditioning, and by 20.3% after 2 weeks. The DF-Hx allowed the formation of more extended and more structured capillary-like networks than DF-Nx or commercially available medium, paving the way to further refinements.

Evaluation of a Serum-Free Medium for Human Epithelial and Stromal Cell Culture

“…The current SFM could be adapted for cell cultures intended for various clinical or fundamental applications. For example, a FBSCM has already been adapted for endothelial cell cultures [ 38 ]. The same conditioning could be applied to the current SFM to cultivate endothelial cells in serum-free and low-cost conditions.…”

Vascularization in skin wound healing: where do we stand and where do we go?

“…The crosstalk between keratinocytes-fibroblasts-ECs is thought to be responsible for regulating microvascular density within the papillary and reticular dermis [52], being therefore also an axis of interest to target during wound healing. Keratinocytes secretome was shown to trigger the secretion of factors such as VEGF-A, FGFs, Ang-1 and hepatocyte growth factor/scatter factor (HGF/ SF) by fibroblasts [53][54][55], known to induce EC migration, tubule formation and stabilization [56,57 ]. Additionally, a stiffer microenvironment formed by ECM proteins deposited by fibroblasts correlates with enhanced EC vessel sprouting with lumen formation [58].…”

Tissue Engineering in Gynecology

“…It presents some of the advantages of collagen but without having exactly the same properties, especially concerning the mechanical properties [16]. Fibrin is the main constituent of blood clots and forms a glue which is widely used as an efficient biological sealant in vivo [17] or to study angiogenesis in vitro in a very simplistic way [18], [19]. Fibrinogen is composed of three regions.…”