Collagenase Impacts the Quantity and Quality of Native Mesenchymal Stem/Stromal Cells Derived during Processing of Umbilical Cord Tissue.

Enzymes are commonly used as a biochemical means to liberate cells from a host of tissues for use in in vitro studies and/or in vivo transplantations. However, very little understanding exists of the biological and functional effects that enzymes have on cells during the process of releasing the native cells from a given tissue. One specific reason for this is that no technology has existed as a nonenzymatic control to compare baseline biology and function for a given processed tissue. We have developed a sterile, onetime use, disposable system (referred to as the AuxoCell Processing System or AC:Px®) that allows for processing of solid tissue in a closed, standardized system using mechanical means to liberate cells without the need and/or use of any biochemical, enzymatic digestion. In this report, for the first time, we directly compare the cellular outputs derived from processing the same umbilical cord tissue (UCT) in the presence and absence of collagenase. In the presence of collagenase, we observed on average, approximately a 2.7-fold reduction in native mesenchymal stem/stromal cell (MSC) yields and a reduction in MSC-specific markers CD90, CD29, CD105, CD73, CD44, CD36, CD49b, CD49a, CD146, CD295, and CD166 and in endothelial marker CD31. These data directly exhibit that the use of collagenase to process UCT to release cells impacts cell recovery with respect to number and cell surface marker expression and, hence, could affect the in vivo function of the recovered native cellular population.

Placental and pregnancy stem cells: everyone is, or should be, interested in the placenta.

The placenta is indeed a miraculous organ. Not only does it provide nutrition in the form of amino acids and glucose to the developing embryo and fetus in the form of amino acids and glucose, but it also acts as an organ of respiration providing oxygen and removing carbon dioxide. It is also an excretory organ. One of the most amazing things about the placenta is its role in stem cell physiology, a role which is only recently being studied and is presented in this issue of Stem Cell Reviews. The placenta may prove to be a noncontroversial source of hematapoetic stem cells (HSCs) and mesenchymal stem cells (MSCs) as well amniotic epitherial (AE) stem cells and endothelial progenitor cells.