In vitro Transcript Expression by Gingival Fibroblasts on Barrier Membranes

Objectives: The ideal barrier membrane (BM) for periodontal surgeries should be cell-occlusive, non-reactive, maintain space, promote healing, and easy to handle. Collagen membranes are widely used, providing a biocompatible scaffold, but success depends on primary closure during healing in order to prevent infection or rapid resorption of the material. Amnion chorion membranes, derived from human placenta, are more recently developed and marketed as having enhanced healing potential for periodontal procedures. Three different barrier membranes were compared for their ability to support cell attachment, differentiation and promote wound healing.
Methods: Three BMs were examined: Bio-Gide™ (collagen), BioMend-Extend™(collagen), and BioXclude™(amnion chorion). Gingival fibroblasts (GFs) were allowed to attach to BMs for 24 hours in minimal essential media containing 10% fetal bovine serum. After attachment, membranes and GFs were transferred to fresh media, and allowed to grow for an additional 48 hours. RNA was isolated from these cells, and differentiation transcripts were examined via RT-PCR.
Results: In general, exposure of GFs to any of the BMs examined resulted in the reduction of expression of growth factor transcripts. However, Biomend-Extend™enhanced the expression of GDF5 and FGF2. Exposure of GFs to BMs resulted in differential increase in expression of cytokine transcripts. Specifically, IL-1β, IL-6, and IL-8 were increased with BioXclude™, while TNFα was increased with Biomend-Extend™. Collagen transcripts were reduced for all membranes. The greatest reduction was observed for Collagen III, V, and VI transcripts.
Conclusions: While all three membranes are designed to block epithelial invasion into a graft site, they also support the survival of gingival fibroblasts. Additionally, these membranes inhibit the expression of transcripts (e.g. BMPs) that would tend to promote epithelial cell differentiation. These membranes differentially support GF expression of growth factors and cytokines that promote wound healing (GDF5, FGF2, IL-1β, IL-6, IL-8, and TNFα).