The Permeability of Human Oral Mucosa and Skin to Water

Abstract

Specimens from four regions of oral mucosa (palate, buccal mucosa, lateral border of the tongue, and the floor of the mouth) and of abdominal skin were taken from 58 individuals at autopsy, for determination of permeability constants (Kp) to tritium-labeled water. Comparisons between fresh specimens and those stored at -80 degrees C revealed no significant effect on Kp as a result of freezing; similar results were found with use of specimens from corresponding regions of the pig. Values for Kp were significantly different for all of the tissue regions examined and ranged from 44 +/- 4 x 10(-7) cm/min for skin to 973 +/- 33 x 10(-7) cm/min for the floor of the mouth, which was the most permeable region. Similar differences were evident among corresponding regions of porcine oral mucosa and skin. Moreover, the Kp values obtained for human tissues were not significantly different from those of the pig, except for the floor of the mouth, which was more permeable in human than in pig tissue. The results reveal interesting differences in the permeability of human oral mucosa that might be related to susceptibility to mucosal disease in those conditions where local extrinsic etiological agents are implicated.

The biological seal of the implant–soft tissue interface evaluated in a tissue-engineered oral mucosal model

“…The test substance, such as radioactive tritiated water, is inoculated in the donor compartment and then the HTO penetrates through the model, which is then collected in the receiver compartment. The samples are normally positioned vertically in the perfusion chamber [22,23]. This is not suitable in our study, as the weight of the Ti disc could damage the interface if it were placed vertically.…”

“…The use of adhesive to form the peripheral seal has been reported in another study on biopsied tissues [23]. Implant -soft tissue interface W. L. Chai et al 3535 Although extra precautions were taken during the clamping of the two components of the inserts, it is possible that the penetration of HTO through the periphery of the inserts could not be completely eliminated.…”

Effect of Freezing and Type of Mucosa on Ex Vivo Drug Permeability Parameters

“…The histological studies were carried out within 2 h after slaughtering. Some samples of these tissues were stored at −80°C (9), no longer than a month, to evaluate the freezing effects of tissues and storage on permeability and barrier integrity. All studies were performed using tissues of different animals in order to check inter-animal variations and to increase the experimental precision.…”

Effect of Experimental Temperature on the Permeation of Model Diffusants Across Porcine Buccal Mucosa

“…However, individual laboratories have used different controlled temperatures, such as room temperature (25°C) (10,(12)(13)(14), 30°C (1), 34°C (15)(16)(17)(18)(19)(20), or physiological temperature (37°C) (21)(22)(23)(24)(25)(26)(27)(28)(29)(30). In the literature, the use of ambient or room temperature (25°C) for permeation studies has been justified by stating that diffusant permeation is not significantly different at body and ambient temperatures (14). It is also stated that since diffusant permeation occurs by simple diffusion across the oral mucosa, it is not affected by metabolic inhibitors (14).…”

“…In the literature, the use of ambient or room temperature (25°C) for permeation studies has been justified by stating that diffusant permeation is not significantly different at body and ambient temperatures (14). It is also stated that since diffusant permeation occurs by simple diffusion across the oral mucosa, it is not affected by metabolic inhibitors (14).…”