Background: Compromised wound healing in irradiated tissues is a common and challenging clinical problem. The pathophysiology and underlying cellular mechanisms including the complex interaction of cytokines and growth factors are still incompletely understood.
Objectives: In this article, the potential of adipose-derived stem cells concerning the treatment of wound healing complications after radiotherapy is discussed.
Methods: Human dermal fibroblasts (NHF), microvascular endothelial cells (HDMEC) and human adipose-derived stem cells (ASC) were cultured in a co-culture setting and irradiated with doses of 2-12Gy. Cell count was determined and levels of cytokines and growth factors relevant for wound healing were measured using enzyme-linked immunosorbent assays (ELISA) and qPCR techniques. Irradiated NHF, HDMEC and ASC as well as non-irradiated mono and co-cultures, NHF, HDMEC or ASC respectively were used as controls.
Results: Cell count was significantly reduced in irradiated co-cultures of NHF, HDMEC and ASC compared to non-irradiated controls. Levels of IL-6, bFGF, ICAM-1 and VCAM-1 in the supernatants of the co-cultures were significantly less affected by external radiation in comparison to HDMEC. Levels of IL-6 and VEGF in the supernatants of co-cultures were significantly less affected by external radiation in comparison to NHF.
Discussion: The increased expression of cytokines and adhesion molecules by NHF and HDMEC after external radiation is mitigated in the co-culture setting with ASC. These in vitro changes seem to support the clinical observation that ASC may have a stabilizing effect when injected into irradiated wounds.