The amniotic membrane may be considered as an attractive dressing material. However, the application of a fresh amnion in clinical practice meets several obstacles, mainly its limited availability, and possible risk of infectious factors transmission. Therefore, different procedures of sterilization and preservation of the amniotic membrane have been developed. Although these procedures destroy all viable components of tissue, the biostatic amniotic dressing may still display some beneficial properties. The aim of the study was to explain a possible mechanism of its action using in vitro HaCaT cell proliferation assay and biochemical analysis of accelerated electron beam-sterilized amniotic membrane dressing. The presence of biologically active factors in the amnion samples was assessed using protein microarray, whereas the amount and quality of hyaluronan was verified using polyacrylamide gel electrophoresis/silver staining method.
The sterilized amniotic membrane stimulated HaCaT cells proliferation in vitro. Interestingly, although hyaluronidase itself did not reveal toxicity against HaCaT cells, this effect was partially reduced by addition of hyaluronidase to the culture. As expected, a gel electrophoresis has confirmed the presence of high molecular weight hyaluronan polymers in amniotic dressing. Moreover, the sterilization procedure did not significantly influence the amount and quality of these molecules.
A protein microarray analysis of radiation-sterilized amniotic membranes revealed significant amounts of various proliferation-stimulating factors, including epidermal growth factor (EGF), angiogenin (ANG), insulin-like growth factor-binding protein (IGFBP) and serpin E1. It is plausible that all of them, together with high molecular weight hyaluronan polymers, could contribute to the proliferation-stimulating action of irradiated amniotic membrane dressing.