Migration of human gingival fibroblasts over guided tissue regeneration barrier materials
The purpose of this investigation was to determine the ability of human gingival fibroblasts, in vitro, to migrate along a chemotactic gradient over three different GTR barrier materials: expanded polytetrafluoroethylene (ePTFE), polylactic acid (PLA), and sterile calcium sulfate.
Human gingival fibroblasts were grown from explants of normal tissue obtained during surgical reduction of retromolar tissues. The in vitro cell migration assay used the under-agarose technique. Forty petri dishes were divided into four equal groups of 10, each with a different cell substrate over which cells migrated: (1) controls (used the polystyrene floor of the petri dish), (2) ePTFE barrier membrane, (3) PLA barrier membrane, and (4) sterile calcium sulfate. Cellular migration was determined by cell polarity, indicating direction of migration, and by identifying a minimum of 20 cells that were used as markers to establish the leading front of migration. The distance from the edge of the central well to the leading front then was measured by using an inverted microscope of 40 times magnification. Three wells were positioned to overlay the barrier substrate. One well (the center well) contained the fibroblasts, one well contained a neutral Hank's solution as a control, and the remaining well contained platelet-derived growth factor-BB homodimer (PDGF-BB).
Of the three barrier materials, calcium sulfate facilitated fibroblast migration to a greater degree than did either ePTFE or PLA. Fibroblast migration for controls was significantly greater than any of the three barrier materials. Scanning electron microscopic examination of fibroblasts cultured directly on barrier membranes and compared to controls indicated that the calcium sulfate substrate appeared to facilitate cell attachment and spreading, whereas cells on ePTFE and PLA barriers exhibited a morphology not conducive to migration or cell health.
Based on the limited results in this study, it appears that of the three experimental barrier materials, the calcium sulfate offers the greatest potential for GTR in surgical sites lacking primary closure. [D.S.S.]
Payne, J., C. Cobb, J. Rapley, W. Killoy, and P. Spencer, J Periodont, 67:236, 1996