Development, characterisation and application of a tissue engineered human oral mucosal model for biocompatibility studies
Restorative materials and oral health care products come into direct contact with oral mucosa and can cause adverse reactions. To obtain an accurate risk assessment, the in vitro test model must reflect the clinical situation as closely as possible. The aim of this project was to develop, characterise and examine a three-dimensional full-thickness engineered human oral mucosal model for biocompatibility assessment of dental materials.
Above: Histological section through a sample of the engineered human oral mucosal model developed at Sheffield.
In a study approved by the South Sheffield Research Ethics Committee oral keratinocytes and fibroblasts were isolated from patients having oral surgery with their written informed consent. The cells were expanded in vitro and seeded onto a number of collagen-based and synthetic scaffolds using a variety of cell seeding techniques and grown at the air/liquid interface to construct human oral mucosa equivalents. Suitability of ten different scaffolds for engineering oral mucosa was evaluated in terms of biocompatibility, biostability, porosity, and the ability to mimic normal human oral mucosa morphology. An optimised full-thickness engineered oral mucosa was developed and characterised using histology, transmission electron microscopy and immunofluorescence studies. Finally the engineered human oral mucosa was exposed to different experimental dental composite resins in a direct contact format and the biological response of the oral mucosal model was evaluated by histology, Alamar Blue tissue viability assay and human IL-1 release measurement by ELISA.
Above: Oral mucosal models inside cell culture inserts cultured at the air/liquid interface.
The optimised oral mucosa reconstruct resembled native human oral mucosa and it is believed to be more clinically relevant than monolayer culture of epithelial cells and the results obtained from multiple-endpoint analysis of the oral mucosal model were more informative.
Researchers active in this area include Prof. Ian M Brook, Dr Keyvan Moharamzadeh, Dr Andy Scutt (Engineering Materials) and Prof. Richard van Noort.