Permeability barrier properties of oral keratinocyte cultures: a model of intact human oral mucosa.
OBJECTIVE
The aim of this study was to establish whether an in vitro model of human oral mucosa had similar permeability characteristics to normal oral mucosa. Such a model would have considerable value as an alternative to the use of mucosal biopsies in studies of transmucosal drug delivery.


METHODS
Keratinocytes obtained from buccal mucosa, hard palate and abdominal skin were seeded onto inert collagen membranes (Cellagen Discs) or dead de-epidermised dermis (DDED) and grown either as submerged or air-liquid interface cultures. Subsequently the ultrastructural characteristics, permeability to water and barrier lipid content of the epithelial cultures were assessed and compared with samples of intact mucosa and skin.


RESULTS
All the cultures stratified into multilayered epithelia and displayed features of differentiation including tonofilaments, desmosomes and membrane coating granules. The permeability characteristics and barrier lipid content of the oral mucosal cultures resembled those of intact mucosa. By contrast, epidermal keratinocytes failed to produce a permeability barrier comparable with that of skin and had low levels of barrier associated lipids.


CONCLUSIONS
Cultures of human oral mucosal keratinocytes obtained from healthy adults develop similar permeability properties and barrier lipid composition to their site of origin. This model system may be useful for the evaluation of local and systemic oral mucosal drug delivery.
Selvaratnam
L
L
Clinical and Diagnostic Oral Sciences, Barts and the London, Queen Mary's School of Medicine and Dentistry, Whitechapel, UK.
Cruchley
A T
AT
Navsaria
H
H
Wertz
P W
PW
Hagi-Pavli
E P
EP
Leigh
I M
IM
Squier
C A
CA
Williams
D M
DM
D000328:Adult; D000704:Analysis of Variance; D002454:Cell Differentiation; D002462:Cell Membrane / Q000648:ultrastructure; D002478:Cells, Cultured; D002518:Ceramides / Q000032:analysis; D002784:Cholesterol / Q000032:analysis; D003094:Collagen; D020405:Dermis; D003896:Desmosomes / Q000648:ultrastructure; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism / Q000648:ultrastructure; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007382:Intermediate Filaments / Q000648:ultrastructure; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D008055:Lipids / Q000032:analysis; D008567:Membranes, Artificial; D009061:Mouth Mucosa / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D021362:Palate, Hard / Q000166:cytology; D010539:Permeability; D010743:Phospholipids / Q000032:analysis; D012867:Skin / Q000166:cytology; D013223:Statistics as Topic; D014867:Water / Q000378:metabolism
D002518:Ceramides; D008055:Lipids; D008567:Membranes, Artificial; D010743:Phospholipids; D014867:Water; D003094:Collagen; D002784:Cholesterol