Inducing proliferation of human amnion epithelial and mesenchymal cells for prospective engineering of membrane repair.

OBJECTIVE To prepare a tissue engineering approach to fetal membrane repair after premature rupture of the membranes (PROM) by characterizing the proliferation potential of human amnion epithelial and mesenchymal cells from preterm and term placenta in primary culture. METHODS Amnion epithelial and mesenchymal cells from 15 preterm (23-36 week) and 27 term placentas collected at cesarean section were separated enzymatically, characterized immunohistochemically (anti-cytokeratin 18 and anti-E-cadherin, and anti-vimentin, respectively), and their ratio determined. Proliferation on tissue culture polystyrene (TCPS) or collagen in one medium and on TCPS in four different media after 14 days was measured photometrically and compared in preterm vs. term placenta. For statistical analysis the Mann-Whitney test was used. RESULTS Preterm and term epithelial:mesenchymal cell ratios were 4.3:1 and 7.8:1. Term epithelial cells proliferated similarly on TCPS or collagen. Mesenchymal cells proliferated only with fetal bovine serum (FBS). Proliferation of term amnion cells in medium containing FBS, epithelial growth factor (EGF), insulin, transferrin and triidothyronine(T3) was significantly increased (p < 0.001) compared with the other three media, and percentage proliferation was slightly higher in preterm cells. CONCLUSION Characterization of human amnion epithelial and mesenchymal cells identified the most potent proliferation-inducing medium yet. Studies of the wound-healing potential of these cells are needed, examining their behavior and proliferation on fibrin microbeads and other extracellular matrixes as the next step towards engineering membrane repair in PROM.