A COMPARISON OF THE ABILITY OF INTRA ORAL AND EXTRA ORAL FIBROBLASTS TO STIMULATE EXTRACELLULAR-MATRIX REORGANIZATION IN A MODEL OF WOUND CONTRACTION

Intra-oral wounds, like wounds in children, demonstrate privileged hea ling when compared with adult wounds at extra-oral sites. This study i nvestigated whether this preferential healing is related to an increas ed ability of oral mucosal fibroblasts to reorganize extracellular mat rix (ECM) when compared with their dermal counterparts. ECM reorganiza tion was investigated by means of a fibroblast-populated collagen latt ice (FPCL) system. The effect of donor age was also investigated in th is system. Differences in ECM reorganization and FPCL contraction were evident: FPCL contraction was more rapid by oral mucosal fibroblasts than dermal fibroblasts (p < 0.01). FPCL contraction was also greater in child (donor < 10 years) than adult (donor > 18 years) oral mucosal fibroblasts (p < 0.01). These differences were not related to phenoty pic differences in cell viability (p > 0.5), DNA synthesis (p > 0.05), and cell number (p > 0.5) within the FPCLs, or cellular attachment to collagen (p > 0.07). FPCL contraction was not stimulated by the addit ion of conditioned medium from oral mucosal or dermal fibroblasts (p > 0.05). These data show that the significantly increased ability of or al mucosal fibroblasts to reorganize ECM in vitro, when compared with dermal fibroblasts, represents a distinct phenotypic contractile diffe rence, rather than differences in their production of soluble mediator s or cell attachment to ECM.