In Vitro Histological Investigation of Interactions between Rat's Mesenchymal Stem Cells and Human Gingival Matrix

Extracellular matrix of natural tissues can be used as a scaffold for reconstructing biological tissues and organs. In this study, decellularized human gingival matrix was used as a scaffold for investigating the interactions of rat’s bone marrow mesenchymal stem cells with human gingival matrix.

To reach this goal, human gingival tissues were decellularized by two detergents sodium dodecyl sulfate (SDS) and Triton X-100. After washing and sterilization procedures, scaffolds were divided into 3 groups. Low density (LD) group was cultivated with 8×104 cells /cm2, high density (HD) group was cultivated with 8×105 cells/cm2, and control (C) group, was maintained in culture medium without any cells. Microscopic sections were prepared from the scaffoldsbefore and after 1, 2 and 4 weeks of culture with mesenchymal cells and were stained with Hematoxylin-Eosin. Repeated measure ANOVA was used to study the cell density alteration significance within the matrixes and post tests of means comparisons were performed within and between the groups. Also, gingival samples before and after decellularization procedure were investigated by scanning electron microscopy.

Histological study of decellularized scaffolds revealed that nuclear and cellular components of the tissues were completely removed. Scanning electron microscopy of the scaffolds indicated that collagen fibers of connective tissue remained intact. Study of the scaffolds 1, 2 and 4 weeks after culture, revealed penetration of mesenchymal stem cells in scaffold, migration of cells towards connective tissue’s papilla, and moreover epithelium-like structures. Statistical analysis indicated that cell density in HD group was significantly (P<0.05) higher than LD group. Cell density in both LD and HD groups significantly increased at 2nd week and decreased after4 weeks of culture.

According to the results, scaffolds prepared from human gingival matrix can be a suitable scaffold for studying In vitro cell behaviors during oral wound healing.