The effects of preservation procedures on amniotic membrane’s ability to serve as a substrate for cultivation of endothelial cells

Cryopreserved amniotic membrane as transplant allograft: viability and post-transplant outcome

“…Cell viability in different layers of the AM was assessed using fluorescent nuclear dyes detectable by confocal microscopy, a technique not routinely performed by clinical tissue banks. Others have shown that trypan blue exclusion and Giemsa staining are sufficient to provide an indication of tissue integrity (Kruse et al 2000;Rama et al 2001;Hennerbichler et al 2007;Niknejad et al 2011;Laurent et al 2014). However, confocal microscopy offers distinct advantages over conventional fluorescent microscopy including the capability to control the depth of field, eliminate or reduce background noise from the focal plane, collect serial optical sections, and obtain extremely high-quality images from thick specimens.…”

“…This becomes relevant in situations when AM allografts are primarily used as a matrix or scaffold. For example, lyophilized AM is a suitable matrix for ex vivo culture of rat endothelial cells because lyophilisation exposed the extracellular components of the basement membrane which induced the adhesion and proliferation of the endothelial cells (Niknejad et al 2011). Decellularized or denuded AM grafts are also preferred for tissue engineering applications (Niknejad et al 2008;Hopkinson et al 2008).…”

“…The cells in the epithelial and stromal layers produce biological factors and mediators that contribute to the therapeutic benefits of AM including anti-bacterial, antiviral, anti-inflammatory, anti-fibrotic, anti-angiogenic, pro-apoptotic, pro-epithelialization and analgesic properties (Wolbank et al 2009;Mamede et al 2012;Werber and Martin 2013;Ricci et al 2013;Fairbairn et al 2014). Aside from being a source of non-immunogenic multipotent cells, AM can also serve as a scaffold and substrate for the growth, migration and adhesion of resident cells and thus find widespread applications in regenerative medicine, cellular therapy and tissue engineering (Niknejad et al 2008(Niknejad et al , 2011Shortt et al 2009;Mamede et al 2012;Kim et al 2014). In addition to its favourable features, AM is readily available because placentas are traditionally considered as medical waste after childbirth.…”

Extract of fetal membrane would inhibit thrombosis and hemolysis

“…Limbal epithelial cells [46], corneal endothelial cells [47], and also vascular endothelial cells [48,49] have been successfully cultivated on the basement membrane of the AM for ophthalmological purposes or vascular tissue engineering. The cultivated cells on the AM basement membrane have appropriate attachment and also good proliferation capacity [47,48]. So, there is an opportunity to have a confluent layer of endothelial cells on the AM to prevent coagulation after contact with blood.…”

Safety of placental, umbilical cord and fetal membrane explants after cryopreservation

“…Described bio-objects can be used to produce stem cells [14,20], in an experiment, testing of pharmaceuticals [10], auto-banking [17], for laboratory studies [7,9]. Fetal membranes are used as scaffolds for constructions in tissue engineering [15,16], allografts in reconstructive surgery [11,18] and ophthalmology [13,6]. Several studies have considered the expediency of isolating cells not from the native, but from the frozen placental material [19], which greatly simplifies the technology of low-temperature banking, eliminating the need to isolate cells in a short time after the birth of the placenta.…”