Regeneration of neomucosa using cell-seeded collagen-GAG matrices in athymic mice

Tissue engineering of oral mucosa could allow improved reconstructive options for intraoral tissue defects. Porous collagen-glycosaminoglycan (CG) matrices coated with a silicone elastomer were seeded by centrifugation with cultured human oral mucosal epithelial cells (strain OKG4 gingival keratinocytes) at a density of 250,000 cells per square centimeter. Full-thickness dorsal wounds (1.5 × 1.5 cm) were created surgically on each athymic mouse and were treated with either a seeded matrix or an unseeded matrix, or they were left open as a control. The CG matrices reduced the degree of wound contraction at day 14 compared with open wounds. The epithelial thickness of seeded matrices at day 14 was significantly greater (p = 0.0001) than that of unseeded matrices. Seeded matrices had more rapid degradation at 14 days compared with unseeded matrices. Human oral mucosal cells seeded into CG matrices contribute to form a stratified and differentiated epithelial layer during revascularization, cellular infiltration, and degradation of the CG matrix.