A One-stage Approach to Reconstruction of Oral Mucosa Defects

Objectives: The aim of this study was to assess the effectiveness of combining freshly excised oral mucosa tissue with different biological and synthetic scaffolds for production of graft material for one stage soft tissue reconstruction. Methods: Rat oral mucosa biopsies (3 mm) were finely minced and transplanted onto a circular subcutaneous wound bed (size 10 mm in diameter) on the back of the animals using custom made stainless steel wound chambers. Test groups included explants seeded onto (1) PLGA electrospun scaffold, (2) Alloderm on the basement membrane side and (3) directly on the muscle fascia with no membrane (N=3). The animals were sacrificed 14 days after implantation and the soft tissue implants were excised and processed for histology and immunohistochemical analysis for cytokeratins (CK) 5, 10, 13, and 19. Results: Mucosal explants grew into multilayered and fully developed epithelium complete with keratinisation. Surprisingly, instead of spreading over the surface of the membranes, the epithelial explants curled up and formed cyst-like structures in all test groups. The epithelial layer of the cysts originated from mucosal explants grown on the electrospun scaffold showed weak positive staining for CK5, CK10, and CK19 similar to native rat oral mucosa. The cysts grown on Alloderm and on the muscle fascia with no carrier membrane showed negative staining for the cytokeratins. Conclusion: Subcutaneous transplantation of freshly excised oral mucosa explants resulted in the growth of the explants and formation of inclusion cyst-like structures. The phenotype of the cyst epithelium was affected by the underlying connective tissue substrate.

This study was supported by a pump priming research grant from Yorkshire Cancer Research.